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Revision 793 - (show annotations)
Wed Dec 7 16:52:34 2011 UTC (9 years, 9 months ago) by ph10
File size: 223284 byte(s)
Computation of memory needed for the table of names of groups was giving an 
unnecessarily large value.
1 ChangeLog for PCRE
2 ------------------
4 Version 8.21 05-Dec-2011
5 ------------------------
7 1. Updating the JIT compiler.
9 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
10 are added as well.
12 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
13 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
14 calling _pcre_jit_exec. Some extra comments are added.
16 4. (*MARK) settings inside atomic groups that do not contain any capturing
17 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
18 was introduced by change 18 for 8.20.
20 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
21 ECMA-262 standard.
23 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
24 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
25 This bug was probably introduced by change 9 of 8.13.
27 7. While fixing 6 above, I noticed that a number of other items were being
28 incorrectly rejected as "not fixed length". This arose partly because newer
29 opcodes had not been added to the fixed-length checking code. I have (a)
30 corrected the bug and added tests for these items, and (b) arranged for an
31 error to occur if an unknown opcode is encountered while checking for fixed
32 length instead of just assuming "not fixed length". The items that were
33 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
34 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
35 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
37 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
38 being incorrectly compiled and would have given unpredicatble results.
40 9. A possessively repeated subpattern with minimum repeat count greater than
41 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
42 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
43 the first (A) could occur when it should not.
45 10. Add a cast and remove a redundant test from the code.
47 11. JIT should use pcre_malloc/pcre_free for allocation.
49 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
50 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
51 is anything other than /usr, -L is still shown).
53 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
55 14. Perl does not support \N without a following name in a [] class; PCRE now
56 also gives an error.
58 15. If a forward reference was repeated with an upper limit of around 2000,
59 it caused the error "internal error: overran compiling workspace". The
60 maximum number of forward references (including repeats) was limited by the
61 internal workspace, and dependent on the LINK_SIZE. The code has been
62 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
63 the default depends on LINK_SIZE. There is a new upper limit (for safety)
64 of around 200,000 forward references. While doing this, I also speeded up
65 the filling in of repeated forward references.
67 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
68 incorrectly expecting the subject to contain another "a" after the start.
70 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
71 in the match, the SKIP should be ignored. This was not happening; instead
72 the SKIP was being treated as NOMATCH. For patterns such as
73 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
74 tested.
76 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
77 now much more compatible with Perl, in particular in cases where the result
78 is a non-match for a non-anchored pattern. For example, if
79 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
80 "m", where previously it did not return a name. A side effect of this
81 change is that for partial matches, the last encountered mark name is
82 returned, as for non matches. A number of tests that were previously not
83 Perl-compatible have been moved into the Perl-compatible test files. The
84 refactoring has had the pleasing side effect of removing one argument from
85 the match() function, thus reducing its stack requirements.
87 19. If the /S+ option was used in pcretest to study a pattern using JIT,
88 subsequent uses of /S (without +) incorrectly behaved like /S+.
90 21. Retrieve executable code size support for the JIT compiler and fixing
91 some warnings.
93 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
94 not work when the shorter character appeared right at the end of the
95 subject string.
97 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
98 systems.
100 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
101 output it when the /M option is used in pcretest.
103 25. The CheckMan script was not being included in the distribution. Also, added
104 an explicit "perl" to run Perl scripts from the PrepareRelease script
105 because this is reportedly needed in Windows.
107 26. If study data was being save in a file and studying had not found a set of
108 "starts with" bytes for the pattern, the data written to the file (though
109 never used) was taken from uninitialized memory and so caused valgrind to
110 complain.
112 27. Updated RunTest.bat as provided by Sheri Pierce.
114 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
116 29. Computation of memory usage for the table of capturing group names was
117 giving an unnecessarily large value.
120 Version 8.20 21-Oct-2011
121 ------------------------
123 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
124 a POSIX class. After further experiments with Perl, which convinced me that
125 Perl has bugs and confusions, a closing square bracket is no longer allowed
126 in a POSIX name. This bug also affected patterns with classes that started
127 with full stops.
129 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
130 captured substring, but while checking the failing first alternative,
131 substring 1 is temporarily captured. If the output vector supplied to
132 pcre_exec() was not big enough for this capture, the yield of the function
133 was still zero ("insufficient space for captured substrings"). This cannot
134 be totally fixed without adding another stack variable, which seems a lot
135 of expense for a edge case. However, I have improved the situation in cases
136 such as /(a)(b)x|abc/ matched against "abc", where the return code
137 indicates that fewer than the maximum number of slots in the ovector have
138 been set.
140 3. Related to (2) above: when there are more back references in a pattern than
141 slots in the output vector, pcre_exec() uses temporary memory during
142 matching, and copies in the captures as far as possible afterwards. It was
143 using the entire output vector, but this conflicts with the specification
144 that only 2/3 is used for passing back captured substrings. Now it uses
145 only the first 2/3, for compatibility. This is, of course, another edge
146 case.
148 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
149 main code base, and can be used by building with --enable-jit. When this is
150 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
151 runtime --no-jit option is given.
153 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
154 ovector, the return from the function was zero, implying that there were
155 other matches that did not fit. The correct "exactly full" value is now
156 returned.
158 6. If a subpattern that was called recursively or as a subroutine contained
159 (*PRUNE) or any other control that caused it to give a non-standard return,
160 invalid errors such as "Error -26 (nested recursion at the same subject
161 position)" or even infinite loops could occur.
163 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
164 computing the minimum length on reaching *ACCEPT, and so ended up with the
165 wrong value of 1 rather than 0. Further investigation indicates that
166 computing a minimum subject length in the presence of *ACCEPT is difficult
167 (think back references, subroutine calls), and so I have changed the code
168 so that no minimum is registered for a pattern that contains *ACCEPT.
170 8. If (*THEN) was present in the first (true) branch of a conditional group,
171 it was not handled as intended. [But see 16 below.]
173 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
174 Sheri Pierce.
176 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
177 the first byte in a match must be "a".
179 11. Change 17 for 8.13 increased the recursion depth for patterns like
180 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
181 pattern contains any instances of (*THEN). If it does not, the old
182 optimizations are restored. It would be nice to do this on a per-group
183 basis, but at the moment that is not feasible.
185 12. In some environments, the output of pcretest -C is CRLF terminated. This
186 broke RunTest's code that checks for the link size. A single white space
187 character after the value is now allowed for.
189 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
190 For "fr", it uses the Windows-specific input and output files.
192 14. If (*THEN) appeared in a group that was called recursively or as a
193 subroutine, it did not work as intended. [But see next item.]
195 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
196 pattern fragments (but not containing any | characters). If A and B are
197 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
198 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
199 D. In other words, Perl considers parentheses that do not contain any |
200 characters to be part of a surrounding alternative, whereas PCRE was
201 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
202 differently. PCRE now behaves in the same way as Perl, except in the case
203 of subroutine/recursion calls such as (?1) which have in any case always
204 been different (but PCRE had them first :-).
206 16. Related to 15 above: Perl does not treat the | in a conditional group as
207 creating alternatives. Such a group is treated in the same way as an
208 ordinary group without any | characters when processing (*THEN). PCRE has
209 been changed to match Perl's behaviour.
211 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
212 RunGrepTest script failed.
214 18. Change 22 for version 13 caused atomic groups to use more stack. This is
215 inevitable for groups that contain captures, but it can lead to a lot of
216 stack use in large patterns. The old behaviour has been restored for atomic
217 groups that do not contain any capturing parentheses.
219 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
220 suppress the check for a minimum subject length at run time. (If it was
221 given to pcre_exec() or pcre_dfa_exec() it did work.)
223 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
224 fail to work when decoding hex characters in data strings in EBCDIC
225 environments.
227 21. It appears that in at least one Mac OS environment, the isxdigit() function
228 is implemented as a macro that evaluates to its argument more than once,
229 contravening the C 90 Standard (I haven't checked a later standard). There
230 was an instance in pcretest which caused it to go wrong when processing
231 \x{...} escapes in subject strings. The has been rewritten to avoid using
232 things like p++ in the argument of isxdigit().
235 Version 8.13 16-Aug-2011
236 ------------------------
238 1. The Unicode data tables have been updated to Unicode 6.0.0.
240 2. Two minor typos in pcre_internal.h have been fixed.
242 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
243 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
244 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
246 4. There were a number of related bugs in the code for matching backrefences
247 caselessly in UTF-8 mode when codes for the characters concerned were
248 different numbers of bytes. For example, U+023A and U+2C65 are an upper
249 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
250 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
251 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
252 2-byte code at the end of the subject (it thought there wasn't enough data
253 left).
255 5. Comprehensive information about what went wrong is now returned by
256 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
257 as the output vector has at least 2 elements. The offset of the start of
258 the failing character and a reason code are placed in the vector.
260 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
261 now returned is for the first byte of the failing character, instead of the
262 last byte inspected. This is an incompatible change, but I hope it is small
263 enough not to be a problem. It makes the returned offset consistent with
264 pcre_exec() and pcre_dfa_exec().
266 7. pcretest now gives a text phrase as well as the error number when
267 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
268 failure, the offset and reason code are output.
270 8. When \R was used with a maximizing quantifier it failed to skip backwards
271 over a \r\n pair if the subsequent match failed. Instead, it just skipped
272 back over a single character (\n). This seems wrong (because it treated the
273 two characters as a single entity when going forwards), conflicts with the
274 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
275 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
276 has been changed.
278 9. Some internal refactoring has changed the processing so that the handling
279 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
280 time (the PCRE_DOTALL option was changed this way some time ago: version
281 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
282 which was always a bit of a fudge. It also means that there is one less
283 argument for the match() function, which reduces its stack requirements
284 slightly. This change also fixes an incompatibility with Perl: the pattern
285 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
287 10. More internal refactoring has drastically reduced the number of recursive
288 calls to match() for possessively repeated groups such as (abc)++ when
289 using pcre_exec().
291 11. While implementing 10, a number of bugs in the handling of groups were
292 discovered and fixed:
294 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
295 (a|)*(?1) gave a compile-time internal error.
296 ((a|)+)+ did not notice that the outer group could match an empty string.
297 (^a|^)+ was not marked as anchored.
298 (.*a|.*)+ was not marked as matching at start or after a newline.
300 12. Yet more internal refactoring has removed another argument from the match()
301 function. Special calls to this function are now indicated by setting a
302 value in a variable in the "match data" data block.
304 13. Be more explicit in pcre_study() instead of relying on "default" for
305 opcodes that mean there is no starting character; this means that when new
306 ones are added and accidentally left out of pcre_study(), testing should
307 pick them up.
309 14. The -s option of pcretest has been documented for ages as being an old
310 synonym of -m (show memory usage). I have changed it to mean "force study
311 for every regex", that is, assume /S for every regex. This is similar to -i
312 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
313 using it. It makes it easier to run collections of tests with and without
314 study enabled, and thereby test pcre_study() more easily. All the standard
315 tests are now run with and without -s (but some patterns can be marked as
316 "never study" - see 20 below).
318 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
319 restoration of the capturing data to the outer values was not happening
320 correctly.
322 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
323 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
324 pattern had matched an empty string, and so incorrectly returned a no
325 match.
327 17. There was optimizing code for the last branch of non-capturing parentheses,
328 and also for the obeyed branch of a conditional subexpression, which used
329 tail recursion to cut down on stack usage. Unfortunately, now that there is
330 the possibility of (*THEN) occurring in these branches, tail recursion is
331 no longer possible because the return has to be checked for (*THEN). These
332 two optimizations have therefore been removed. [But see 8.20/11 above.]
334 18. If a pattern containing \R was studied, it was assumed that \R always
335 matched two bytes, thus causing the minimum subject length to be
336 incorrectly computed because \R can also match just one byte.
338 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
339 was incorrectly computed.
341 20. If /S is present twice on a test pattern in pcretest input, it now
342 *disables* studying, thereby overriding the use of -s on the command line
343 (see 14 above). This is necessary for one or two tests to keep the output
344 identical in both cases.
346 21. When (*ACCEPT) was used in an assertion that matched an empty string and
347 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
349 22. When an atomic group that contained a capturing parenthesis was
350 successfully matched, but the branch in which it appeared failed, the
351 capturing was not being forgotten if a higher numbered group was later
352 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
353 group 1 to "a", when in fact it should be unset. This applied to multi-
354 branched capturing and non-capturing groups, repeated or not, and also to
355 positive assertions (capturing in negative assertions does not happen
356 in PCRE) and also to nested atomic groups.
358 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
359 subject after a captured substring, to make it easier to tell which of a
360 number of identical substrings has been captured.
362 24. The way atomic groups are processed by pcre_exec() has been changed so that
363 if they are repeated, backtracking one repetition now resets captured
364 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
365 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
366 "aaa". Previously, it would have been "a". As part of this code
367 refactoring, the way recursive calls are handled has also been changed.
369 25. If an assertion condition captured any substrings, they were not passed
370 back unless some other capturing happened later. For example, if
371 (?(?=(a))a) was matched against "a", no capturing was returned.
373 26. When studying a pattern that contained subroutine calls or assertions,
374 the code for finding the minimum length of a possible match was handling
375 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
376 group 1 called group 2 while simultaneously a separate group 2 called group
377 1). A stack overflow occurred in this case. I have fixed this by limiting
378 the recursion depth to 10.
380 27. Updated RunTest.bat in the distribution to the version supplied by Tom
381 Fortmann. This supports explicit test numbers on the command line, and has
382 argument validation and error reporting.
384 28. An instance of \X with an unlimited repeat could fail if at any point the
385 first character it looked at was a mark character.
387 29. Some minor code refactoring concerning Unicode properties and scripts
388 should reduce the stack requirement of match() slightly.
390 30. Added the '=' option to pcretest to check the setting of unused capturing
391 slots at the end of the pattern, which are documented as being -1, but are
392 not included in the return count.
394 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
395 compiled something random. Now it gives a compile-time error (as does
396 Perl).
398 32. A *MARK encountered during the processing of a positive assertion is now
399 recorded and passed back (compatible with Perl).
401 33. If --only-matching or --colour was set on a pcregrep call whose pattern
402 had alternative anchored branches, the search for a second match in a line
403 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
404 matched the line "0102" twice. The same bug affected patterns that started
405 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
406 twice.
408 34. Previously, PCRE did not allow quantification of assertions. However, Perl
409 does, and because of capturing effects, quantifying parenthesized
410 assertions may at times be useful. Quantifiers are now allowed for
411 parenthesized assertions.
413 35. A minor code tidy in pcre_compile() when checking options for \R usage.
415 36. \g was being checked for fancy things in a character class, when it should
416 just be a literal "g".
418 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
419 appearance of a nested POSIX class supersedes an apparent external class.
420 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
421 unescaped square brackets may also appear as part of class names. For
422 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
423 more like Perl. (But see 8.20/1 above.)
425 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
426 was because it thought it was \N{name}, which is not supported).
428 39. Add minix to OS list not supporting the -S option in pcretest.
430 40. PCRE tries to detect cases of infinite recursion at compile time, but it
431 cannot analyze patterns in sufficient detail to catch mutual recursions
432 such as ((?1))((?2)). There is now a runtime test that gives an error if a
433 subgroup is called recursively as a subpattern for a second time at the
434 same position in the subject string. In previous releases this might have
435 been caught by the recursion limit, or it might have run out of stack.
437 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
438 happen only once. PCRE was, however incorrectly giving a compile time error
439 "recursive call could loop indefinitely" because it cannot analyze the
440 pattern in sufficient detail. The compile time test no longer happens when
441 PCRE is compiling a conditional subpattern, but actual runaway loops are
442 now caught at runtime (see 40 above).
444 42. It seems that Perl allows any characters other than a closing parenthesis
445 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
446 has been changed to be the same.
448 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
449 as not to get warnings when autogen.sh is called. Also changed
450 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
452 44. To help people who use pcregrep to scan files containing exceedingly long
453 lines, the following changes have been made:
455 (a) The default value of the buffer size parameter has been increased from
456 8K to 20K. (The actual buffer used is three times this size.)
458 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
459 PCRE is built.
461 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
462 to be set at run time.
464 (d) Numerical values in pcregrep options can be followed by K or M, for
465 example --buffer-size=50K.
467 (e) If a line being scanned overflows pcregrep's buffer, an error is now
468 given and the return code is set to 2.
470 45. Add a pointer to the latest mark to the callout data block.
472 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
473 partial match of an empty string instead of no match. This was specific to
474 the use of ".".
476 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
477 complete match instead of a partial match. This bug was dependent on both
478 the PCRE_UTF8 and PCRE_DOTALL options being set.
480 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
481 starting byte set, because \b was not being ignored.
484 Version 8.12 15-Jan-2011
485 ------------------------
487 1. Fixed some typos in the markup of the man pages, and wrote a script that
488 checks for such things as part of the documentation building process.
490 2. On a big-endian 64-bit system, pcregrep did not correctly process the
491 --match-limit and --recursion-limit options (added for 8.11). In
492 particular, this made one of the standard tests fail. (The integer value
493 went into the wrong half of a long int.)
495 3. If the --colour option was given to pcregrep with -v (invert match), it
496 did strange things, either producing crazy output, or crashing. It should,
497 of course, ignore a request for colour when reporting lines that do not
498 match.
500 4. Another pcregrep bug caused similar problems if --colour was specified with
501 -M (multiline) and the pattern match finished with a line ending.
503 5. In pcregrep, when a pattern that ended with a literal newline sequence was
504 matched in multiline mode, the following line was shown as part of the
505 match. This seems wrong, so I have changed it.
507 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
508 the check for further matches in the same line (so they could be coloured)
509 to overrun the end of the current line. If another match was found, it was
510 incorrectly shown (and then shown again when found in the next line).
512 7. If pcregrep was compiled under Windows, there was a reference to the
513 function pcregrep_exit() before it was defined. I am assuming this was
514 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
515 reported by a user. I've moved the definition above the reference.
518 Version 8.11 10-Dec-2010
519 ------------------------
521 1. (*THEN) was not working properly if there were untried alternatives prior
522 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
523 backtracked to try for "b" instead of moving to the next alternative branch
524 at the same level (in this case, to look for "c"). The Perl documentation
525 is clear that when (*THEN) is backtracked onto, it goes to the "next
526 alternative in the innermost enclosing group".
528 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
529 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
530 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
531 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
532 (*THEN).
534 3. If \s appeared in a character class, it removed the VT character from
535 the class, even if it had been included by some previous item, for example
536 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
537 of \s, but is part of the POSIX "space" class.)
539 4. A partial match never returns an empty string (because you can always
540 match an empty string at the end of the subject); however the checking for
541 an empty string was starting at the "start of match" point. This has been
542 changed to the "earliest inspected character" point, because the returned
543 data for a partial match starts at this character. This means that, for
544 example, /(?<=abc)def/ gives a partial match for the subject "abc"
545 (previously it gave "no match").
547 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
548 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
549 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
550 has an implication that the given string is incomplete (because a partial
551 match is preferred over a full match). For this reason, these items now
552 give a partial match in this situation. [Aside: previously, the one case
553 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
554 match rather than a full match, which was wrong by the old rules, but is
555 now correct.]
557 6. There was a bug in the handling of #-introduced comments, recognized when
558 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
559 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
560 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
561 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
562 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
563 places in pcre_compile().
565 7. Related to (6) above, when pcre_compile() was skipping #-introduced
566 comments when looking ahead for named forward references to subpatterns,
567 the only newline sequence it recognized was NL. It now handles newlines
568 according to the set newline convention.
570 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
571 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
572 cater for a lack of strerror(). These oversights have been fixed.
574 9. Added --match-limit and --recursion-limit to pcregrep.
576 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
578 11. When the -o option was used, pcregrep was setting a return code of 1, even
579 when matches were found, and --line-buffered was not being honoured.
581 12. Added an optional parentheses number to the -o and --only-matching options
582 of pcregrep.
584 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
585 can match an empty string. The code to do it in pcretest and pcredemo
586 needed fixing:
588 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
589 only one byte after an empty string match just before CRLF (this case
590 just got forgotten; "any" and "anycrlf" were OK).
592 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
593 mode when an empty string match preceded an ASCII character followed by
594 a non-ASCII character. (The code for advancing by one character rather
595 than one byte was nonsense.)
597 (c) The pcredemo.c sample program did not have any code at all to handle
598 the cases when CRLF is a valid newline sequence.
600 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
601 as a starting offset was within the subject string. There is now a new
602 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
603 negative or greater than the length of the string. In order to test this,
604 pcretest is extended to allow the setting of negative starting offsets.
606 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
607 starting offset points to the beginning of a UTF-8 character was
608 unnecessarily clumsy. I tidied it up.
610 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
611 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
613 17. Nobody had reported that the --include_dir option, which was added in
614 release 7.7 should have been called --include-dir (hyphen, not underscore)
615 for compatibility with GNU grep. I have changed it to --include-dir, but
616 left --include_dir as an undocumented synonym, and the same for
617 --exclude-dir, though that is not available in GNU grep, at least as of
618 release 2.5.4.
620 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
621 characters from a string of bytes) have been redefined so as not to use
622 loops, in order to improve performance in some environments. At the same
623 time, I abstracted some of the common code into auxiliary macros to save
624 repetition (this should not affect the compiled code).
626 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
627 compile-time error is now given if \c is not followed by an ASCII
628 character, that is, a byte less than 128. (In EBCDIC mode, the code is
629 different, and any byte value is allowed.)
631 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
632 START_OPTIMIZE option, which is now allowed at compile time - but just
633 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
634 to pcregrep and other applications that have no direct access to PCRE
635 options. The new /Y option in pcretest sets this option when calling
636 pcre_compile().
638 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
639 back references. Groups containing recursive back references were forced to
640 be atomic by that change, but in the case of named groups, the amount of
641 memory required was incorrectly computed, leading to "Failed: internal
642 error: code overflow". This has been fixed.
644 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
645 pcretest.c, to avoid build problems in some Borland environments.
648 Version 8.10 25-Jun-2010
649 ------------------------
651 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
652 THEN.
654 2. (*ACCEPT) was not working when inside an atomic group.
656 3. Inside a character class, \B is treated as a literal by default, but
657 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
658 causes the error). The code is unchanged, but I tidied the documentation.
660 4. Inside a character class, PCRE always treated \R and \X as literals,
661 whereas Perl faults them if its -w option is set. I have changed PCRE so
662 that it faults them when PCRE_EXTRA is set.
664 5. Added support for \N, which always matches any character other than
665 newline. (It is the same as "." when PCRE_DOTALL is not set.)
667 6. When compiling pcregrep with newer versions of gcc which may have
668 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
669 declared with attribute warn_unused_result" were given. Just casting the
670 result to (void) does not stop the warnings; a more elaborate fudge is
671 needed. I've used a macro to implement this.
673 7. Minor change to pcretest.c to avoid a compiler warning.
675 8. Added four artifical Unicode properties to help with an option to make
676 \s etc use properties (see next item). The new properties are: Xan
677 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
679 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
680 use Unicode properties. (*UCP) at the start of a pattern can be used to set
681 this option. Modified pcretest to add /W to test this facility. Added
682 REG_UCP to make it available via the POSIX interface.
684 10. Added --line-buffered to pcregrep.
686 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
687 studied, and the match started with a letter with a code point greater than
688 127 whose first byte was different to the first byte of the other case of
689 the letter, the other case of this starting letter was not recognized
690 (#976).
692 12. If a pattern that was studied started with a repeated Unicode property
693 test, for example, \p{Nd}+, there was the theoretical possibility of
694 setting up an incorrect bitmap of starting bytes, but fortunately it could
695 not have actually happened in practice until change 8 above was made (it
696 added property types that matched character-matching opcodes).
698 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
699 possible starting bytes for non-anchored patterns.
701 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
702 \R, and also a number of cases that involve Unicode properties, both
703 explicit and implicit when PCRE_UCP is set.
705 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
706 input, it could crash or give wrong results if characters with values
707 greater than 0xc0 were present in the subject string. (Detail: it assumed
708 UTF-8 input when processing these items.)
710 16. Added a lot of (int) casts to avoid compiler warnings in systems where
711 size_t is 64-bit (#991).
713 17. Added a check for running out of memory when PCRE is compiled with
714 --disable-stack-for-recursion (#990).
716 18. If the last data line in a file for pcretest does not have a newline on
717 the end, a newline was missing in the output.
719 19. The default pcre_chartables.c file recognizes only ASCII characters (values
720 less than 128) in its various bitmaps. However, there is a facility for
721 generating tables according to the current locale when PCRE is compiled. It
722 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
723 characters, are recognized by isspace() and therefore were getting set in
724 these tables, and indeed these tables seem to approximate to ISO 8859. This
725 caused a problem in UTF-8 mode when pcre_study() was used to create a list
726 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
727 which of course cannot start UTF-8 characters. I have changed the code so
728 that only real ASCII characters (less than 128) and the correct starting
729 bytes for UTF-8 encodings are set for characters greater than 127 when in
730 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
731 altogether.)
733 20. Added the /T option to pcretest so as to be able to run tests with non-
734 standard character tables, thus making it possible to include the tests
735 used for 19 above in the standard set of tests.
737 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
738 reference to a subpattern the other side of a comment that contains an
739 opening parenthesis caused either an internal compiling error, or a
740 reference to the wrong subpattern.
743 Version 8.02 19-Mar-2010
744 ------------------------
746 1. The Unicode data tables have been updated to Unicode 5.2.0.
748 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
749 configured.
751 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
752 original author of that file, following a query about its status.
754 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
755 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
757 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
758 quantifier applied to a forward-referencing subroutine call, could compile
759 incorrect code or give the error "internal error: previously-checked
760 referenced subpattern not found".
762 6. Both MS Visual Studio and Symbian OS have problems with initializing
763 variables to point to external functions. For these systems, therefore,
764 pcre_malloc etc. are now initialized to local functions that call the
765 relevant global functions.
767 7. There were two entries missing in the vectors called coptable and poptable
768 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
769 I've fixed the data, and added a kludgy way of testing at compile time that
770 the lengths are correct (equal to the number of opcodes).
772 8. Following on from 7, I added a similar kludge to check the length of the
773 eint vector in pcreposix.c.
775 9. Error texts for pcre_compile() are held as one long string to avoid too
776 much relocation at load time. To find a text, the string is searched,
777 counting zeros. There was no check for running off the end of the string,
778 which could happen if a new error number was added without updating the
779 string.
781 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
783 11. \K was not working if it appeared in an atomic group or in a group that
784 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
785 \K is "not well defined" if used in an assertion. PCRE now accepts it if
786 the assertion is positive, but not if it is negative.
788 12. Change 11 fortuitously reduced the size of the stack frame used in the
789 "match()" function of pcre_exec.c by one pointer. Forthcoming
790 implementation of support for (*MARK) will need an extra pointer on the
791 stack; I have reserved it now, so that the stack frame size does not
792 decrease.
794 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
795 item in branch that calls a recursion is a subroutine call - as in the
796 second branch in the above example - was incorrectly given the compile-
797 time error "recursive call could loop indefinitely" because pcre_compile()
798 was not correctly checking the subroutine for matching a non-empty string.
800 14. The checks for overrunning compiling workspace could trigger after an
801 overrun had occurred. This is a "should never occur" error, but it can be
802 triggered by pathological patterns such as hundreds of nested parentheses.
803 The checks now trigger 100 bytes before the end of the workspace.
805 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
808 Version 8.01 19-Jan-2010
809 ------------------------
811 1. If a pattern contained a conditional subpattern with only one branch (in
812 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
813 computed the wrong minimum data length (which is of course zero for such
814 subpatterns). This could cause incorrect "no match" results.
816 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
817 the pattern is reset in the first branch, pcre_compile() failed with
818 "internal error: code overflow at offset...". This happened only when
819 the reset was to the original external option setting. (An optimization
820 abstracts leading options settings into an external setting, which was the
821 cause of this.)
823 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
824 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
825 assertion pattern did not match (meaning that the assertion was true), it
826 was incorrectly treated as false if the SKIP had been reached during the
827 matching. This also applied to assertions used as conditions.
829 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
830 assertion subpattern, including such a pattern used as a condition,
831 unpredictable results occurred, instead of the error return
834 5. The C++ GlobalReplace function was not working like Perl for the special
835 situation when an empty string is matched. It now does the fancy magic
836 stuff that is necessary.
838 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
839 removed. (These were left over from very, very early versions of PCRE.)
841 7. Some cosmetic changes to the code to make life easier when compiling it
842 as part of something else:
844 (a) Change DEBUG to PCRE_DEBUG.
846 (b) In pcre_compile(), rename the member of the "branch_chain" structure
847 called "current" as "current_branch", to prevent a collision with the
848 Linux macro when compiled as a kernel module.
850 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
851 prevent a collision with the Linux macro when compiled as a kernel
852 module.
854 8. In pcre_compile() there are some checks for integer overflows that used to
855 cast potentially large values to (double). This has been changed to that
856 when building, a check for int64_t is made, and if it is found, it is used
857 instead, thus avoiding the use of floating point arithmetic. (There is no
858 other use of FP in PCRE.) If int64_t is not found, the fallback is to
859 double.
861 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
862 2005 (difference between two addresses compared to an unsigned value).
864 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
865 custom one, because of the following reported problem in Windows:
867 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
868 under Win32.
869 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
870 therefore missing the function definition.
871 - The compiler thus generates a "C" signature for the test function.
872 - The linker fails to find the "C" function.
873 - PCRE fails to configure if asked to do so against libbz2.
875 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
876 messages were output:
878 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
879 rerunning libtoolize, to keep the correct libtool macros in-tree.
880 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
882 I have done both of these things.
884 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
885 most of the time, it *can* run out if it is given a pattern that contains a
886 runaway infinite recursion. I updated the discussion in the pcrestack man
887 page.
889 13. Now that we have gone to the x.xx style of version numbers, the minor
890 version may start with zero. Using 08 or 09 is a bad idea because users
891 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
892 interpreted as invalid octal numbers. I've updated the previous comment in
893 configure.ac, and also added a check that gives an error if 08 or 09 are
894 used.
896 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
897 causing partial matching to fail when the end of the subject matched \W
898 in a UTF-8 pattern where \W was quantified with a minimum of 3.
900 15. There were some discrepancies between the declarations in pcre_internal.h
901 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
902 their definitions. The declarations used "const uschar *" and the
903 definitions used USPTR. Even though USPTR is normally defined as "const
904 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
905 reported that: "This difference in casting confuses some C++ compilers, for
906 example, SunCC recognizes above declarations as different functions and
907 generates broken code for hbpcre." I have changed the declarations to use
908 USPTR.
910 16. GNU libtool is named differently on some systems. The autogen.sh script now
911 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
912 (FreeBSD).
914 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
915 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
916 comment: "Figure out how to create a longlong from a string: strtoll and
917 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
918 instance, but it only takes 2 args instead of 3!"
920 18. A subtle bug concerned with back references has been fixed by a change of
921 specification, with a corresponding code fix. A pattern such as
922 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
923 refers, was giving matches when it shouldn't. For example, xa=xaaa would
924 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
925 same bug. Such groups have to be quantified to be useful, or contained
926 inside another quantified group. (If there's no repetition, the reference
927 can never match.) The problem arises because, having left the group and
928 moved on to the rest of the pattern, a later failure that backtracks into
929 the group uses the captured value from the final iteration of the group
930 rather than the correct earlier one. I have fixed this in PCRE by forcing
931 any group that contains a reference to itself to be an atomic group; that
932 is, there cannot be any backtracking into it once it has completed. This is
933 similar to recursive and subroutine calls.
936 Version 8.00 19-Oct-09
937 ----------------------
939 1. The table for translating pcre_compile() error codes into POSIX error codes
940 was out-of-date, and there was no check on the pcre_compile() error code
941 being within the table. This could lead to an OK return being given in
942 error.
944 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
945 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
946 in a Windows environment.
948 3. The pcregrep --count option prints the count for each file even when it is
949 zero, as does GNU grep. However, pcregrep was also printing all files when
950 --files-with-matches was added. Now, when both options are given, it prints
951 counts only for those files that have at least one match. (GNU grep just
952 prints the file name in this circumstance, but including the count seems
953 more useful - otherwise, why use --count?) Also ensured that the
954 combination -clh just lists non-zero counts, with no names.
956 4. The long form of the pcregrep -F option was incorrectly implemented as
957 --fixed_strings instead of --fixed-strings. This is an incompatible change,
958 but it seems right to fix it, and I didn't think it was worth preserving
959 the old behaviour.
961 5. The command line items --regex=pattern and --regexp=pattern were not
962 recognized by pcregrep, which required --regex pattern or --regexp pattern
963 (with a space rather than an '='). The man page documented the '=' forms,
964 which are compatible with GNU grep; these now work.
966 6. No libpcreposix.pc file was created for pkg-config; there was just
967 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
969 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
970 when UCP support is not needed, by modifying the Python script that
971 generates it from Unicode data files. This should not matter if the module
972 is correctly used as a library, but I received one complaint about 50K of
973 unwanted data. My guess is that the person linked everything into his
974 program rather than using a library. Anyway, it does no harm.
976 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
977 was a minimum greater than 1 for a wide character in a possessive
978 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
979 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
980 character. Chaos in the form of incorrect output or a compiling loop could
981 result.
983 9. The restrictions on what a pattern can contain when partial matching is
984 requested for pcre_exec() have been removed. All patterns can now be
985 partially matched by this function. In addition, if there are at least two
986 slots in the offset vector, the offset of the earliest inspected character
987 for the match and the offset of the end of the subject are set in them when
988 PCRE_ERROR_PARTIAL is returned.
990 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
991 synonymous with PCRE_PARTIAL, for backwards compatibility, and
992 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
993 and may be more useful for multi-segment matching.
995 11. Partial matching with pcre_exec() is now more intuitive. A partial match
996 used to be given if ever the end of the subject was reached; now it is
997 given only if matching could not proceed because another character was
998 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
999 string "Z", which now yields "no match" instead of "partial match". In the
1000 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1001 final character ended with (*FAIL).
1003 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1004 if the pattern had a "must contain" character that was already found in the
1005 earlier partial match, unless partial matching was again requested. For
1006 example, with the pattern /dog.(body)?/, the "must contain" character is
1007 "g". If the first part-match was for the string "dog", restarting with
1008 "sbody" failed. This bug has been fixed.
1010 13. The string returned by pcre_dfa_exec() after a partial match has been
1011 changed so that it starts at the first inspected character rather than the
1012 first character of the match. This makes a difference only if the pattern
1013 starts with a lookbehind assertion or \b or \B (\K is not supported by
1014 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1015 matching functions compatible, and I think it's the right thing to do.
1017 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1018 so that the demonstration program is easily available in environments where
1019 PCRE has not been installed from source.
1021 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1022 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1023 library.
1025 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1026 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1027 is not the first non-POSIX option to be added. Clearly some people find
1028 these options useful.
1030 17. If a caller to the POSIX matching function regexec() passes a non-zero
1031 value for nmatch with a NULL value for pmatch, the value of
1032 nmatch is forced to zero.
1034 18. RunGrepTest did not have a test for the availability of the -u option of
1035 the diff command, as RunTest does. It now checks in the same way as
1036 RunTest, and also checks for the -b option.
1038 19. If an odd number of negated classes containing just a single character
1039 interposed, within parentheses, between a forward reference to a named
1040 subpattern and the definition of the subpattern, compilation crashed with
1041 an internal error, complaining that it could not find the referenced
1042 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1043 [The bug was that it was starting one character too far in when skipping
1044 over the character class, thus treating the ] as data rather than
1045 terminating the class. This meant it could skip too much.]
1047 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1048 /g option in pcretest when the pattern contains \K, which makes it possible
1049 to have an empty string match not at the start, even when the pattern is
1050 anchored. Updated pcretest and pcredemo to use this option.
1052 21. If the maximum number of capturing subpatterns in a recursion was greater
1053 than the maximum at the outer level, the higher number was returned, but
1054 with unset values at the outer level. The correct (outer level) value is
1055 now given.
1057 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1058 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1059 make it do so. The string so far is captured, making this feature
1060 compatible with Perl.
1062 23. The tests have been re-organized, adding tests 11 and 12, to make it
1063 possible to check the Perl 5.10 features against Perl 5.10.
1065 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1066 pattern matches a fixed length string. PCRE did not allow this; now it
1067 does. Neither allows recursion.
1069 25. I finally figured out how to implement a request to provide the minimum
1070 length of subject string that was needed in order to match a given pattern.
1071 (It was back references and recursion that I had previously got hung up
1072 on.) This code has now been added to pcre_study(); it finds a lower bound
1073 to the length of subject needed. It is not necessarily the greatest lower
1074 bound, but using it to avoid searching strings that are too short does give
1075 some useful speed-ups. The value is available to calling programs via
1076 pcre_fullinfo().
1078 26. While implementing 25, I discovered to my embarrassment that pcretest had
1079 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1080 study optimizations had never been tested with that matching function.
1081 Oops. What is worse, even when it was passed study data, there was a bug in
1082 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1083 were also very few tests of studied patterns with pcre_dfa_exec().
1085 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1086 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1087 on the other side of the coin, they are no longer allowed to have different
1088 names, because these cannot be distinguished in PCRE, and this has caused
1089 confusion. (This is a difference from Perl.)
1091 28. When duplicate subpattern names are present (necessarily with different
1092 numbers, as required by 27 above), and a test is made by name in a
1093 conditional pattern, either for a subpattern having been matched, or for
1094 recursion in such a pattern, all the associated numbered subpatterns are
1095 tested, and the overall condition is true if the condition is true for any
1096 one of them. This is the way Perl works, and is also more like the way
1097 testing by number works.
1100 Version 7.9 11-Apr-09
1101 ---------------------
1103 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1104 (pcretest), all targets were linked against these libraries. This included
1105 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1106 libraries. This caused unwanted dependencies to be created. This problem
1107 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1108 pcretest is linked with readline.
1110 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1111 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1112 moved outside it again, because FALSE and TRUE are already defined in AIX,
1113 but BOOL is not.
1115 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1116 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1118 4. The pcregrep documentation said spaces were inserted as well as colons (or
1119 hyphens) following file names and line numbers when outputting matching
1120 lines. This is not true; no spaces are inserted. I have also clarified the
1121 wording for the --colour (or --color) option.
1123 5. In pcregrep, when --colour was used with -o, the list of matching strings
1124 was not coloured; this is different to GNU grep, so I have changed it to be
1125 the same.
1127 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1128 each matching line was coloured. Now it goes on to look for further matches
1129 of any of the test patterns, which is the same behaviour as GNU grep.
1131 7. A pattern that could match an empty string could cause pcregrep to loop; it
1132 doesn't make sense to accept an empty string match in pcregrep, so I have
1133 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1134 seems to be how GNU grep behaves.
1136 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1137 start or after a newline", because the conditional assertion was not being
1138 correctly handled. The rule now is that both the assertion and what follows
1139 in the first alternative must satisfy the test.
1141 9. If auto-callout was enabled in a pattern with a conditional group whose
1142 condition was an assertion, PCRE could crash during matching, both with
1143 pcre_exec() and pcre_dfa_exec().
1145 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1146 used for matching.
1148 11. Unicode property support in character classes was not working for
1149 characters (bytes) greater than 127 when not in UTF-8 mode.
1151 12. Added the -M command line option to pcretest.
1153 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1155 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1157 16. Added comments and documentation about mis-use of no_arg in the C++
1158 wrapper.
1160 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1161 from Martin Jerabek that uses macro names for all relevant character and
1162 string constants.
1164 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1165 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1166 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1167 these, but not everybody uses configure.
1169 19. A conditional group that had only one branch was not being correctly
1170 recognized as an item that could match an empty string. This meant that an
1171 enclosing group might also not be so recognized, causing infinite looping
1172 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1173 with the subject "ab", where knowledge that the repeated group can match
1174 nothing is needed in order to break the loop.
1176 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1177 exec(), but without supplying a callout function, matching went wrong.
1179 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1180 leak if the size of the offset vector was greater than 30. When the vector
1181 is smaller, the saved offsets during recursion go onto a local stack
1182 vector, but for larger vectors malloc() is used. It was failing to free
1183 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1184 error, in fact).
1186 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1187 heapframe that is used only when UTF-8 support is enabled. This caused no
1188 problem, but was untidy.
1190 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1191 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1192 included within another project.
1194 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1195 slightly modified by me:
1197 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1198 not building pcregrep.
1200 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1201 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1203 25. Forward references, both numeric and by name, in patterns that made use of
1204 duplicate group numbers, could behave incorrectly or give incorrect errors,
1205 because when scanning forward to find the reference group, PCRE was not
1206 taking into account the duplicate group numbers. A pattern such as
1207 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1209 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1210 the feature of a custom pointer more persuasive (as requested by a user).
1212 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1213 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1214 pre-defined.
1216 28. Added support for (*UTF8) at the start of a pattern.
1218 29. Arrange for flags added by the "release type" setting in CMake to be shown
1219 in the configuration summary.
1222 Version 7.8 05-Sep-08
1223 ---------------------
1225 1. Replaced UCP searching code with optimized version as implemented for Ad
1226 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1227 stage table and inline lookup instead of a function, giving speed ups of 2
1228 to 5 times on some simple patterns that I tested. Permission was given to
1229 distribute the MultiStage2.py script that generates the tables (it's not in
1230 the tarball, but is in the Subversion repository).
1232 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1233 scripts.
1235 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1236 a group with a zero qualifier. The result of the study could be incorrect,
1237 or the function might crash, depending on the pattern.
1239 4. Caseless matching was not working for non-ASCII characters in back
1240 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1241 It now works when Unicode Property Support is available.
1243 5. In pcretest, an escape such as \x{de} in the data was always generating
1244 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1245 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1246 truncation.
1248 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1250 7. Added two (int) casts to pcregrep when printing the difference of two
1251 pointers, in case they are 64-bit values.
1253 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1254 test 2 if it fails.
1256 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1257 and a #define of that name to empty if it is not externally set. This is to
1258 allow users of MSVC to set it if necessary.
1260 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1261 the convenience functions in the pcre_get.c source file.
1263 11. An option change at the start of a pattern that had top-level alternatives
1264 could cause overwriting and/or a crash. This command provoked a crash in
1265 some environments:
1267 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1269 This potential security problem was recorded as CVE-2008-2371.
1271 12. For a pattern where the match had to start at the beginning or immediately
1272 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1273 pcre_dfa_exec() could read past the end of the passed subject if there was
1274 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1275 pcretest so that it places the subject at the end of its malloc-ed buffer.
1277 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1278 exec() might read past the end of the data buffer in UTF-8 mode.
1280 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1281 the data contained the byte 0x85 as part of a UTF-8 character within its
1282 first line. This applied both to normal and DFA matching.
1284 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1285 /^[^d]*?$/8 failed to match "abc".
1287 16. Added a missing copyright notice to pcrecpp_internal.h.
1289 17. Make it more clear in the documentation that values returned from
1290 pcre_exec() in ovector are byte offsets, not character counts.
1292 18. Tidied a few places to stop certain compilers from issuing warnings.
1294 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1295 supplied by Stefan Weber. I made a further small update for 7.8 because
1296 there is a change of source arrangements: the pcre_searchfuncs.c module is
1297 replaced by pcre_ucd.c.
1300 Version 7.7 07-May-08
1301 ---------------------
1303 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1304 a string to a long long, pretend we don't even have a long long." This is
1305 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1307 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1308 pre-7.6 versions, which defined a global no_arg variable instead of putting
1309 it in the RE class. (See also #8 below.)
1311 3. Remove a line of dead code, identified by coverity and reported by Nuno
1312 Lopes.
1314 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1316 (1) The include/exclude patterns were being applied to the whole pathnames
1317 of files, instead of just to the final components.
1319 (2) If there was more than one level of directory, the subdirectories were
1320 skipped unless they satisfied the include/exclude conditions. This is
1321 inconsistent with GNU grep (and could even be seen as contrary to the
1322 pcregrep specification - which I improved to make it absolutely clear).
1323 The action now is always to scan all levels of directory, and just
1324 apply the include/exclude patterns to regular files.
1326 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1327 --exclude_dir in the tests to avoid scanning .svn directories.
1329 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1330 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1331 doesn't support NULs in patterns.
1333 7. Added some missing "const"s to declarations of static tables in
1334 pcre_compile.c and pcre_dfa_exec.c.
1336 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1337 caused by fix #2 above. (Subsequently also a second patch to fix the
1338 first patch. And a third patch - this was a messy problem.)
1340 9. Applied Craig's patch to remove the use of push_back().
1342 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1343 matching function regexec().
1345 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1346 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1347 references. PCRE supports relative numbers with this syntax (I don't think
1348 Oniguruma does).
1350 12. Previously, a group with a zero repeat such as (...){0} was completely
1351 omitted from the compiled regex. However, this means that if the group
1352 was called as a subroutine from elsewhere in the pattern, things went wrong
1353 (an internal error was given). Such groups are now left in the compiled
1354 pattern, with a new opcode that causes them to be skipped at execution
1355 time.
1357 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1358 to the way PCRE behaves:
1360 (a) A lone ] character is dis-allowed (Perl treats it as data).
1362 (b) A back reference to an unmatched subpattern matches an empty string
1363 (Perl fails the current match path).
1365 (c) A data ] in a character class must be notated as \] because if the
1366 first data character in a class is ], it defines an empty class. (In
1367 Perl it is not possible to have an empty class.) The empty class []
1368 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1369 The negative empty class [^] matches any one character, independently
1370 of the DOTALL setting.
1372 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1373 non-existent subpattern following a character class starting with ']' and
1374 containing () gave an internal compiling error instead of "reference to
1375 non-existent subpattern". Fortunately, when the pattern did exist, the
1376 compiled code was correct. (When scanning forwards to check for the
1377 existencd of the subpattern, it was treating the data ']' as terminating
1378 the class, so got the count wrong. When actually compiling, the reference
1379 was subsequently set up correctly.)
1381 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1382 it was being rejected as not supported by pcre_dfa_exec(), even though
1383 other assertions are supported. I have made pcre_dfa_exec() support
1384 (*FAIL).
1386 16. The implementation of 13c above involved the invention of a new opcode,
1387 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1388 cannot be changed at match time, I realized I could make a small
1389 improvement to matching performance by compiling OP_ALLANY instead of
1390 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1391 on the OP_ANY path.
1393 17. Compiling pcretest on Windows with readline support failed without the
1394 following two fixes: (1) Make the unistd.h include conditional on
1395 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1397 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1398 ncurses library to be included for pcretest when ReadLine support is
1399 requested, but also to allow for it to be overridden. This patch came from
1400 Daniel Bergström.
1402 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1403 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1404 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1405 spotting this.
1408 Version 7.6 28-Jan-08
1409 ---------------------
1411 1. A character class containing a very large number of characters with
1412 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1413 overflow.
1415 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1416 HAVE_LONG_LONG is not defined.
1418 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1419 bring them up to date and include new features. This patch includes:
1421 - Fixed PH's badly added libz and libbz2 support.
1422 - Fixed a problem with static linking.
1423 - Added pcredemo. [But later removed - see 7 below.]
1424 - Fixed dftables problem and added an option.
1425 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1427 - Added readline support for pcretest.
1428 - Added an listing of the option settings after cmake has run.
1430 4. A user submitted a patch to Makefile that makes it easy to create
1431 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1432 Makefile.am that cause it to include this special target, without
1433 affecting anything else. Note that the same mingw target plus all
1434 the other distribution libraries and programs are now supported
1435 when configuring with CMake (see 6 below) instead of with
1436 Configure/Make.
1438 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1439 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1440 exported in the Windows port". It has not yet been confirmed that the patch
1441 solves the problem, but it does no harm.
1443 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1444 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1445 with CMake, and also correct the comment about stack recursion.
1447 7. Remove the automatic building of pcredemo from the ./configure system and
1448 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1449 of a program that users should build themselves after PCRE is installed, so
1450 building it automatically is not really right. What is more, it gave
1451 trouble in some build environments.
1453 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1456 Version 7.5 10-Jan-08
1457 ---------------------
1459 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1460 values in parens when parsing an RE using the C++ wrapper."
1462 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1463 Characters greater than 255 were excluded from the class instead of being
1464 included.
1466 3. The same bug as (2) above applied to negated POSIX classes such as
1467 [:^space:].
1469 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1470 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1471 I have changed it.
1473 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1474 first named subpattern) and a construct such as (?&a) would reference the
1475 first named subpattern whose name started with "a" (in other words, the
1476 length check was missing). Both these problems are fixed. "Subpattern name
1477 expected" is now given for (?&) (a zero-length name), and this patch also
1478 makes it give the same error for \k'' (previously it complained that that
1479 was a reference to a non-existent subpattern).
1481 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1482 this is right because (?- can be followed by option settings as well as by
1483 digits. I have, however, made the messages clearer.
1485 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1486 than the number used in the conditional) now cause a compile-time error.
1487 This is actually not compatible with Perl, which accepts such patterns, but
1488 treats the conditional as always being FALSE (as PCRE used to), but it
1489 seems to me that giving a diagnostic is better.
1491 8. Change "alphameric" to the more common word "alphanumeric" in comments
1492 and messages.
1494 9. Fix two occurrences of "backslash" in comments that should have been
1495 "backspace".
1497 10. Remove two redundant lines of code that can never be obeyed (their function
1498 was moved elsewhere).
1500 11. The program that makes PCRE's Unicode character property table had a bug
1501 which caused it to generate incorrect table entries for sequences of
1502 characters that have the same character type, but are in different scripts.
1503 It amalgamated them into a single range, with the script of the first of
1504 them. In other words, some characters were in the wrong script. There were
1505 thirteen such cases, affecting characters in the following ranges:
1507 U+002b0 - U+002c1
1508 U+0060c - U+0060d
1509 U+0061e - U+00612
1510 U+0064b - U+0065e
1511 U+0074d - U+0076d
1512 U+01800 - U+01805
1513 U+01d00 - U+01d77
1514 U+01d9b - U+01dbf
1515 U+0200b - U+0200f
1516 U+030fc - U+030fe
1517 U+03260 - U+0327f
1518 U+0fb46 - U+0fbb1
1519 U+10450 - U+1049d
1521 12. The -o option (show only the matching part of a line) for pcregrep was not
1522 compatible with GNU grep in that, if there was more than one match in a
1523 line, it showed only the first of them. It now behaves in the same way as
1524 GNU grep.
1526 13. If the -o and -v options were combined for pcregrep, it printed a blank
1527 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1528 does the same. The return code can be used to tell if there were any
1529 non-matching lines.
1531 14. Added --file-offsets and --line-offsets to pcregrep.
1533 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1534 infinitely looping recursion. The bug was that positive lookaheads were not
1535 being skipped when checking for a possible empty match (negative lookaheads
1536 and both kinds of lookbehind were skipped).
1538 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1539 inclusion of <windows.h> to before rather than after the definition of
1540 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1542 17. Specifying a possessive quantifier with a specific limit for a Unicode
1543 character property caused pcre_compile() to compile bad code, which led at
1544 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1545 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1546 caused the error; without that there was no problem.
1548 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1550 19. Added --enable-pcretest-libreadline.
1552 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1553 RE::GlobalReplace(). As a result, the number of replacements returned was
1554 double what it should be. I removed one of the increments, but Craig sent a
1555 later patch that removed the other one (the right fix) and added unit tests
1556 that check the return values (which was not done before).
1558 21. Several CMake things:
1560 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1561 the names libpcre and libpcreposix, not just pcre and pcreposix.
1563 (2) The above change means that pcretest and pcregrep are now correctly
1564 linked with the newly-built libraries, not previously installed ones.
1568 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1569 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1570 UTF-8 newline character). The key issue is that the pattern starts .*;
1571 this means that the match must be either at the beginning, or after a
1572 newline. The bug was in the code for advancing after a failed match and
1573 checking that the new position followed a newline. It was not taking
1574 account of UTF-8 characters correctly.
1576 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1577 character classes. PCRE was not treating the sequence [:...:] as a
1578 character class unless the ... were all letters. Perl, however, seems to
1579 allow any characters between [: and :], though of course it rejects as
1580 unknown any "names" that contain non-letters, because all the known class
1581 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1582 for example, whereas PCRE did not - it did not recognize a POSIX character
1583 class. This seemed a bit dangerous, so the code has been changed to be
1584 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1585 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1586 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1587 Perl does, and where it didn't before.
1589 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1590 Windows environments %n is disabled by default.
1593 Version 7.4 21-Sep-07
1594 ---------------------
1596 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1597 means that a class such as [\s] counted as "explicit reference to CR or
1598 LF". That isn't really right - the whole point of the change was to try to
1599 help when there was an actual mention of one of the two characters. So now
1600 the change happens only if \r or \n (or a literal CR or LF) character is
1601 encountered.
1603 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1604 of both had grown to the point where there were only 3 bits left.
1605 Fortunately, there was spare space in the data structure, and so I have
1606 moved the internal flags into a new 16-bit field to free up more option
1607 bits.
1609 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1610 but did not set the internal JCHANGED flag - either of these is enough to
1611 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1612 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1613 start sets both bits.
1615 4. Added options (at build time, compile time, exec time) to change \R from
1616 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1618 5. doc/pcresyntax.html was missing from the distribution.
1620 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1621 compatibility, even though it is no longer used.
1623 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1624 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1625 windows.h file is present (where different names are used). [This was
1626 reversed later after testing - see 16 below.]
1628 8. Changed all #include <config.h> to #include "config.h". There were also
1629 some further <pcre.h> cases that I changed to "pcre.h".
1631 9. When pcregrep was used with the --colour option, it missed the line ending
1632 sequence off the lines that it output.
1634 10. It was pointed out to me that arrays of string pointers cause lots of
1635 relocations when a shared library is dynamically loaded. A technique of
1636 using a single long string with a table of offsets can drastically reduce
1637 these. I have refactored PCRE in four places to do this. The result is
1638 dramatic:
1640 Originally: 290
1641 After changing UCP table: 187
1642 After changing error message table: 43
1643 After changing table of "verbs" 36
1644 After changing table of Posix names 22
1646 Thanks to the folks working on Gregex for glib for this insight.
1648 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1649 unicode-properties was also set.
1651 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1653 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1654 checked only for CRLF.
1656 14. Added casts to pcretest.c to avoid compiler warnings.
1658 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1660 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1661 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1662 entirely. This removes changes made in 7 above.
1664 17. The CMake files have been updated, and there is now more information about
1665 building with CMake in the NON-UNIX-USE document.
1668 Version 7.3 28-Aug-07
1669 ---------------------
1671 1. In the rejigging of the build system that eventually resulted in 7.1, the
1672 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1673 brackets there is not right, since it causes compilers to look for an
1674 installed pcre.h, not the version that is in the source that is being
1675 compiled (which of course may be different). I have changed it back to:
1677 #include "pcre.h"
1679 I have a vague recollection that the change was concerned with compiling in
1680 different directories, but in the new build system, that is taken care of
1681 by the VPATH setting the Makefile.
1683 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1684 when the subject happened to end in the byte 0x85 (e.g. if the last
1685 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1686 characters but of course it shouldn't be taken as a newline when it is part
1687 of another character. The bug was that, for an unlimited repeat of . in
1688 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1689 characters when looking for a newline.
1691 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1693 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1694 in debug output.
1696 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1697 long printing in the pcrecpp unittest when running under MinGW.
1699 6. ESC_K was left out of the EBCDIC table.
1701 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1702 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1703 limit also applies to "virtual nesting" when a pattern is recursive, and in
1704 this case 1000 isn't so big. I have been able to remove this limit at the
1705 expense of backing off one optimization in certain circumstances. Normally,
1706 when pcre_exec() would call its internal match() function recursively and
1707 immediately return the result unconditionally, it uses a "tail recursion"
1708 feature to save stack. However, when a subpattern that can match an empty
1709 string has an unlimited repetition quantifier, it no longer makes this
1710 optimization. That gives it a stack frame in which to save the data for
1711 checking that an empty string has been matched. Previously this was taken
1712 from the 1000-entry workspace that had been reserved. So now there is no
1713 explicit limit, but more stack is used.
1715 8. Applied Daniel's patches to solve problems with the import/export magic
1716 syntax that is required for Windows, and which was going wrong for the
1717 pcreposix and pcrecpp parts of the library. These were overlooked when this
1718 problem was solved for the main library.
1720 9. There were some crude static tests to avoid integer overflow when computing
1721 the size of patterns that contain repeated groups with explicit upper
1722 limits. As the maximum quantifier is 65535, the maximum group length was
1723 set at 30,000 so that the product of these two numbers did not overflow a
1724 32-bit integer. However, it turns out that people want to use groups that
1725 are longer than 30,000 bytes (though not repeat them that many times).
1726 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1727 made it possible to implement the integer overflow checks in a much more
1728 dynamic way, which I have now done. The artificial limitation on group
1729 length has been removed - we now have only the limit on the total length of
1730 the compiled pattern, which depends on the LINK_SIZE setting.
1732 10. Fixed a bug in the documentation for get/copy named substring when
1733 duplicate names are permitted. If none of the named substrings are set, the
1734 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1735 empty string.
1737 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1738 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1739 because the ] is interpreted as the first data character and the
1740 terminating ] is not found. PCRE has been made compatible with Perl in this
1741 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1742 cause memory overwriting.
1744 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1745 string has been matched (to stop an infinite loop). It was not recognizing
1746 a conditional subpattern that could match an empty string if that
1747 subpattern was within another subpattern. For example, it looped when
1748 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1749 condition was not nested. This bug has been fixed.
1751 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1752 past the start of the subject in the presence of bytes with the top bit
1753 set, for example "\x8aBCD".
1755 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1756 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1758 14. Optimized (?!) to (*FAIL).
1760 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1761 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1762 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1763 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1764 does: it's just the validity check that is more restrictive.
1766 16. Inserted checks for integer overflows during escape sequence (backslash)
1767 processing, and also fixed erroneous offset values for syntax errors during
1768 backslash processing.
1770 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1771 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1773 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1774 caused an overrun.
1776 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1777 something other than just ASCII characters) inside a group that had an
1778 unlimited repeat caused a loop at compile time (while checking to see
1779 whether the group could match an empty string).
1781 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1782 [\P{Any}] did so. (Error in the code for printing property names.)
1784 21. An orphan \E inside a character class could cause a crash.
1786 22. A repeated capturing bracket such as (A)? could cause a wild memory
1787 reference during compilation.
1789 23. There are several functions in pcre_compile() that scan along a compiled
1790 expression for various reasons (e.g. to see if it's fixed length for look
1791 behind). There were bugs in these functions when a repeated \p or \P was
1792 present in the pattern. These operators have additional parameters compared
1793 with \d, etc, and these were not being taken into account when moving along
1794 the compiled data. Specifically:
1796 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1797 length.
1799 (b) An item such as \pL+ within a repeated group could cause crashes or
1800 loops.
1802 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1803 "reference to non-existent subpattern" error.
1805 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1807 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1808 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1810 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1812 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1813 character were causing crashes (broken optimization).
1815 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1816 \p or \P) caused a compile-time loop.
1818 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1819 break. For example, the unstudied pattern [\r\n]A does not match the string
1820 "\r\nA" because change 7.0/46 below moves the current point on by two
1821 characters after failing to match at the start. However, the pattern \nA
1822 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1823 the same is true. There doesn't seem any very clean way out of this, but
1824 what I have chosen to do makes the common cases work: PCRE now takes note
1825 of whether there can be an explicit match for \r or \n anywhere in the
1826 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1827 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1828 pattern has explicit CR or LF references.
1830 29. Added (*CR) etc for changing newline setting at start of pattern.
1833 Version 7.2 19-Jun-07
1834 ---------------------
1836 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1837 which is apparently normally available under Windows.
1839 2. Re-jig the pcregrep tests with different newline settings in an attempt
1840 to make them independent of the local environment's newline setting.
1842 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1844 4. Some of the "internals" tests were previously cut out when the link size
1845 was not 2, because the output contained actual offsets. The recent new
1846 "Z" feature of pcretest means that these can be cut out, making the tests
1847 usable with all link sizes.
1849 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1850 stack recursion. This gives a massive performance boost under BSD, but just
1851 a small improvement under Linux. However, it saves one field in the frame
1852 in all cases.
1854 6. Added more features from the forthcoming Perl 5.10:
1856 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1857 recursion call. It refers to the nth most recently opened parentheses.
1859 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1860 to be opened parentheses.
1862 (c) Conditions that refer to capturing parentheses can be specified
1863 relatively, for example, (?(-2)... or (?(+3)...
1865 (d) \K resets the start of the current match so that everything before
1866 is not part of it.
1868 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1870 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1871 reference syntax.
1873 (g) (?| introduces a group in which the numbering of parentheses in each
1874 alternative starts with the same number.
1876 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1878 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1881 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1882 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1883 for detecting groups that can match an empty string.
1885 9. A pattern with a very large number of alternatives (more than several
1886 hundred) was running out of internal workspace during the pre-compile
1887 phase, where pcre_compile() figures out how much memory will be needed. A
1888 bit of new cunning has reduced the workspace needed for groups with
1889 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1890 workspace instead of running out of the 4096 that are available.
1892 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1894 11. Applied patch from Google to remove an optimization that didn't quite work.
1895 The report of the bug said:
1897 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1898 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1899 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1901 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1902 it matched the wrong number of bytes.
1905 Version 7.1 24-Apr-07
1906 ---------------------
1908 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1909 that is more "standard", making use of automake and other Autotools. There
1910 is some re-arrangement of the files and adjustment of comments consequent
1911 on this.
1913 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1914 for recursive directory scanning broke on some systems because the files
1915 are not scanned in any specific order and on different systems the order
1916 was different. A call to "sort" has been inserted into RunGrepTest for the
1917 approprate test as a short-term fix. In the longer term there may be an
1918 alternative.
1920 3. I had an email from Eric Raymond about problems translating some of PCRE's
1921 man pages to HTML (despite the fact that I distribute HTML pages, some
1922 people do their own conversions for various reasons). The problems
1923 concerned the use of low-level troff macros .br and .in. I have therefore
1924 removed all such uses from the man pages (some were redundant, some could
1925 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1926 HTML has been updated to handle .nf/.fi and to complain if it encounters
1927 .br or .in.
1929 4. Updated comments in configure.ac that get placed in config.h.in and also
1930 arranged for config.h to be included in the distribution, with the name
1931 config.h.generic, for the benefit of those who have to compile without
1932 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1934 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1935 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1936 makevp.bat for the current PCRE, using the additional files
1937 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1939 6. A Windows user reported a minor discrepancy with test 2, which turned out
1940 to be caused by a trailing space on an input line that had got lost in his
1941 copy. The trailing space was an accident, so I've just removed it.
1943 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1944 that is needed.
1946 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1947 as "const" (a) because they are and (b) because it helps the PHP
1948 maintainers who have recently made a script to detect big data structures
1949 in the php code that should be moved to the .rodata section. I remembered
1950 to update Builducptable as well, so it won't revert if ucptable.h is ever
1951 re-created.
1953 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1954 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1955 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1956 support is not required. This saves 1.5-2K of code, which is important in
1957 some applications.
1959 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1960 so as not to refer to the tables, even though these functions will never be
1961 called when UTF-8 support is disabled. Otherwise there are problems with a
1962 shared library.
1964 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1966 (a) It was defining its arguments as char * instead of void *.
1968 (b) It was assuming that all moves were upwards in memory; this was true
1969 a long time ago when I wrote it, but is no longer the case.
1971 The emulated memove() is provided for those environments that have neither
1972 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1973 is clearly not the case, as these two bugs were recently reported.
1975 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1976 and Detrail to create the HTML documentation, the .txt form of the man
1977 pages, and it removes trailing spaces from listed files. It also creates
1978 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1979 case, it wraps all the #defines with #ifndefs. This script should be run
1980 before "make dist".
1982 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1983 with Unicode property support.
1985 (a) For a maximizing quantifier, if the two different cases of the
1986 character were of different lengths in their UTF-8 codings (there are
1987 some cases like this - I found 11), and the matching function had to
1988 back up over a mixture of the two cases, it incorrectly assumed they
1989 were both the same length.
1991 (b) When PCRE was configured to use the heap rather than the stack for
1992 recursion during matching, it was not correctly preserving the data for
1993 the other case of a UTF-8 character when checking ahead for a match
1994 while processing a minimizing repeat. If the check also involved
1995 matching a wide character, but failed, corruption could cause an
1996 erroneous result when trying to check for a repeat of the original
1997 character.
1999 13. Some tidying changes to the testing mechanism:
2001 (a) The RunTest script now detects the internal link size and whether there
2002 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2003 values substituted by "configure". (The RunGrepTest script already did
2004 this for UTF-8.) The configure.ac script no longer substitutes the
2005 relevant variables.
2007 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2008 with length and offset values. This means that the output is different
2009 for different internal link sizes. Test 2 is skipped for link sizes
2010 other than 2 because of this, bypassing the problem. Unfortunately,
2011 there was also a test in test 3 (the locale tests) that used /B and
2012 failed for link sizes other than 2. Rather than cut the whole test out,
2013 I have added a new /Z option to pcretest that replaces the length and
2014 offset values with spaces. This is now used to make test 3 independent
2015 of link size. (Test 2 will be tidied up later.)
2017 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2018 segmentation fault instead of returning the appropriate error message.
2020 15. In multiline mode when the newline sequence was set to "any", the pattern
2021 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2022 This doesn't seem right; it now treats the CRLF combination as the line
2023 ending, and so does not match in that case. It's only a pattern such as ^$
2024 that would hit this one: something like ^ABC$ would have failed after \r
2025 and then tried again after \r\n.
2027 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2028 in an attempt to make files that differ only in their line terminators
2029 compare equal. This works on Linux.
2031 17. Under certain error circumstances pcregrep might try to free random memory
2032 as it exited. This is now fixed, thanks to valgrind.
2034 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2035 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2036 was because its rules for how to advance for /g after matching an empty
2037 string at the end of a line did not allow for this case. They now check for
2038 it specially.
2040 20. pcretest is supposed to handle patterns and data of any length, by
2041 extending its buffers when necessary. It was getting this wrong when the
2042 buffer for a data line had to be extended.
2044 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2045 CRLF as a newline sequence.
2047 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2048 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2049 I have nevertheless tidied it up.
2051 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2053 24. Added a man page for pcre-config.
2056 Version 7.0 19-Dec-06
2057 ---------------------
2059 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2060 moving to gcc 4.1.1.
2062 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2063 sys/time.h, which is documented as needed for this function. It doesn't
2064 seem to matter on Linux, but it showed up on some releases of OS X.
2066 3. It seems that there are systems where bytes whose values are greater than
2067 127 match isprint() in the "C" locale. The "C" locale should be the
2068 default when a C program starts up. In most systems, only ASCII printing
2069 characters match isprint(). This difference caused the output from pcretest
2070 to vary, making some of the tests fail. I have changed pcretest so that:
2072 (a) When it is outputting text in the compiled version of a pattern, bytes
2073 other than 32-126 are always shown as hex escapes.
2075 (b) When it is outputting text that is a matched part of a subject string,
2076 it does the same, unless a different locale has been set for the match
2077 (using the /L modifier). In this case, it uses isprint() to decide.
2079 4. Fixed a major bug that caused incorrect computation of the amount of memory
2080 required for a compiled pattern when options that changed within the
2081 pattern affected the logic of the preliminary scan that determines the
2082 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2083 that the computed length was too small. The symptoms of this bug were
2084 either the PCRE error "internal error: code overflow" from pcre_compile(),
2085 or a glibc crash with a message such as "pcretest: free(): invalid next
2086 size (fast)". Examples of patterns that provoked this bug (shown in
2087 pcretest format) are:
2089 /(?-x: )/x
2090 /(?x)(?-x: \s*#\s*)/
2091 /((?i)[\x{c0}])/8
2092 /(?i:[\x{c0}])/8
2094 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2095 is now done differently.
2097 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2098 wrapper classes; (b) implement a new function in the C++ scanner that is
2099 more efficient than the old way of doing things because it avoids levels of
2100 recursion in the regex matching; (c) add a paragraph to the documentation
2101 for the FullMatch() function.
2103 6. The escape sequence \n was being treated as whatever was defined as
2104 "newline". Not only was this contrary to the documentation, which states
2105 that \n is character 10 (hex 0A), but it also went horribly wrong when
2106 "newline" was defined as CRLF. This has been fixed.
2108 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2109 was being set to -1 for the "end of line" case (supposedly a value that no
2110 character can have). Though this value is never used (the check for end of
2111 line is "zero bytes in current character"), it caused compiler complaints.
2112 I've changed it to 0xffffffff.
2114 8. In pcre_version.c, the version string was being built by a sequence of
2115 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2116 string (as it is for production releases) called a macro with an empty
2117 argument. The C standard says the result of this is undefined. The gcc
2118 compiler treats it as an empty string (which was what was wanted) but it is
2119 reported that Visual C gives an error. The source has been hacked around to
2120 avoid this problem.
2122 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2123 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2124 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2125 of them did).
2127 10. Originally, pcretest opened its input and output without "b"; then I was
2128 told that "b" was needed in some environments, so it was added for release
2129 5.0 to both the input and output. (It makes no difference on Unix-like
2130 systems.) Later I was told that it is wrong for the input on Windows. I've
2131 now abstracted the modes into two macros, to make it easier to fiddle with
2132 them, and removed "b" from the input mode under Windows.
2134 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2136 12. Added -help and --help to pcretest as an official way of being reminded
2137 of the options.
2139 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2140 and pcrecpp.cc because they annoy compilers at high warning levels.
2142 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2144 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2145 scripts are not C programs :-) and which was not noticed because it works
2146 on Linux.
2148 16. pcretest is supposed to handle any length of pattern and data line (as one
2149 line or as a continued sequence of lines) by extending its input buffer if
2150 necessary. This feature was broken for very long pattern lines, leading to
2151 a string of junk being passed to pcre_compile() if the pattern was longer
2152 than about 50K.
2154 17. I have done a major re-factoring of the way pcre_compile() computes the
2155 amount of memory needed for a compiled pattern. Previously, there was code
2156 that made a preliminary scan of the pattern in order to do this. That was
2157 OK when PCRE was new, but as the facilities have expanded, it has become
2158 harder and harder to keep it in step with the real compile phase, and there
2159 have been a number of bugs (see for example, 4 above). I have now found a
2160 cunning way of running the real compile function in a "fake" mode that
2161 enables it to compute how much memory it would need, while actually only
2162 ever using a few hundred bytes of working memory and without too many
2163 tests of the mode. This should make future maintenance and development
2164 easier. A side effect of this work is that the limit of 200 on the nesting
2165 depth of parentheses has been removed (though this was never a serious
2166 limitation, I suspect). However, there is a downside: pcre_compile() now
2167 runs more slowly than before (30% or more, depending on the pattern). I
2168 hope this isn't a big issue. There is no effect on runtime performance.
2170 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2171 newline (only possible for the last line of a file) and it was a
2172 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2174 19. Added additional timing features to pcretest. (1) The -tm option now times
2175 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2176 separate command line item, by a number that specifies the number of
2177 repeats to use when timing. The default is 50000; this gives better
2178 precision, but takes uncomfortably long for very large patterns.
2180 20. Extended pcre_study() to be more clever in cases where a branch of a
2181 subpattern has no definite first character. For example, (a*|b*)[cd] would
2182 previously give no result from pcre_study(). Now it recognizes that the
2183 first character must be a, b, c, or d.
2185 21. There was an incorrect error "recursive call could loop indefinitely" if
2186 a subpattern (or the entire pattern) that was being tested for matching an
2187 empty string contained only one non-empty item after a nested subpattern.
2188 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2189 incorrectly, because the \d was being skipped in the check.
2191 22. The pcretest program now has a new pattern option /B and a command line
2192 option -b, which is equivalent to adding /B to every pattern. This causes
2193 it to show the compiled bytecode, without the additional information that
2194 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2195 is the same as /B/I).
2197 23. A new optimization is now able automatically to treat some sequences such
2198 as a*b as a*+b. More specifically, if something simple (such as a character
2199 or a simple class like \d) has an unlimited quantifier, and is followed by
2200 something that cannot possibly match the quantified thing, the quantifier
2201 is automatically "possessified".
2203 24. A recursive reference to a subpattern whose number was greater than 39
2204 went wrong under certain circumstances in UTF-8 mode. This bug could also
2205 have affected the operation of pcre_study().
2207 25. Realized that a little bit of performance could be had by replacing
2208 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2210 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2212 27. Possessive quantifiers such as a++ were previously implemented by turning
2213 them into atomic groups such as ($>a+). Now they have their own opcodes,
2214 which improves performance. This includes the automatically created ones
2215 from 23 above.
2217 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2218 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2219 the first matched character to be a colon. This applied both to named and
2220 numbered groups.
2222 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2224 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2225 building PCRE on Windows easier, so I have included it in the distribution.
2227 31. There is now a check in pcretest against a ridiculously large number being
2228 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2229 loop, the loop is abandoned.
2231 32. Forward references to subpatterns in conditions such as (?(2)...) where
2232 subpattern 2 is defined later cause pcre_compile() to search forwards in
2233 the pattern for the relevant set of parentheses. This search went wrong
2234 when there were unescaped parentheses in a character class, parentheses
2235 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2237 33. "Subroutine" calls and backreferences were previously restricted to
2238 referencing subpatterns earlier in the regex. This restriction has now
2239 been removed.
2241 34. Added a number of extra features that are going to be in Perl 5.10. On the
2242 whole, these are just syntactic alternatives for features that PCRE had
2243 previously implemented using the Python syntax or my own invention. The
2244 other formats are all retained for compatibility.
2246 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2247 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2248 also .NET compatible.
2250 (b) A recursion or subroutine call to a named group can now be defined as
2251 (?&name) as well as (?P>name).
2253 (c) A backreference to a named group can now be defined as \k<name> or
2254 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2255 5.10, are also .NET compatible.
2257 (d) A conditional reference to a named group can now use the syntax
2258 (?(<name>) or (?('name') as well as (?(name).
2260 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2261 groups (named and numbered) that are never evaluated inline, but can be
2262 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2263 is always false. There may be only one alternative in such a group.
2265 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2266 as the simple (?(R). The condition is true only if the most recent
2267 recursion is that of the given number or name. It does not search out
2268 through the entire recursion stack.
2270 (g) The escape \gN or \g{N} has been added, where N is a positive or
2271 negative number, specifying an absolute or relative reference.
2273 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2274 some "unreachable code" warnings.
2276 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2277 things, this adds five new scripts.
2279 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2280 There were also incompatibilities regarding the handling of \Q..\E inside
2281 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2282 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2284 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2285 matches an empty string, and forcibly breaks the loop. There were bugs in
2286 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2287 against aaaa the result was just "a" rather than "aaaa", for example. Two
2288 separate and independent bugs (that affected different cases) have been
2289 fixed.
2291 39. Refactored the code to abolish the use of different opcodes for small
2292 capturing bracket numbers. This is a tidy that I avoided doing when I
2293 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2294 The new approach is not only tidier, it makes it possible to reduce the
2295 memory needed to fix the previous bug (38).
2297 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2298 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2299 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2300 mode.
2302 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2303 report.
2305 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2306 copy construction and assignment in the C++ wrapper.
2308 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2309 couple of bugs that could have given wrong results in the "--newline=crlf"
2310 case.
2312 44. Added a number of casts and did some reorganization of signed/unsigned int
2313 variables following suggestions from Dair Grant. Also renamed the variable
2314 "this" as "item" because it is a C++ keyword.
2316 45. Arranged for dftables to add
2318 #include "pcre_internal.h"
2320 to pcre_chartables.c because without it, gcc 4.x may remove the array
2321 definition from the final binary if PCRE is built into a static library and
2322 dead code stripping is activated.
2324 46. For an unanchored pattern, if a match attempt fails at the start of a
2325 newline sequence, and the newline setting is CRLF or ANY, and the next two
2326 characters are CRLF, advance by two characters instead of one.
2329 Version 6.7 04-Jul-06
2330 ---------------------
2332 1. In order to handle tests when input lines are enormously long, pcretest has
2333 been re-factored so that it automatically extends its buffers when
2334 necessary. The code is crude, but this _is_ just a test program. The
2335 default size has been increased from 32K to 50K.
2337 2. The code in pcre_study() was using the value of the re argument before
2338 testing it for NULL. (Of course, in any sensible call of the function, it
2339 won't be NULL.)
2341 3. The memmove() emulation function in pcre_internal.h, which is used on
2342 systems that lack both memmove() and bcopy() - that is, hardly ever -
2343 was missing a "static" storage class specifier.
2345 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2346 containing an extended class (one that cannot be represented by a bitmap
2347 because it contains high-valued characters or Unicode property items, e.g.
2348 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2349 pattern, but PCRE should not loop if you do not (it no longer does).
2350 [Detail: two cases were found: (a) a repeated subpattern containing an
2351 extended class; (b) a recursive reference to a subpattern that followed a
2352 previous extended class. It wasn't skipping over the extended class
2353 correctly when UTF-8 mode was not set.]
2355 5. A negated single-character class was not being recognized as fixed-length
2356 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2357 compile error "lookbehind assertion is not fixed length".
2359 6. The RunPerlTest auxiliary script was showing an unexpected difference
2360 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2361 write a Perl script that can interpret lines of an input file either as
2362 byte characters or as UTF-8, which is what "perltest" was being required to
2363 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2364 can't do is switch easily at run time between having the "use utf8;" pragma
2365 or not. In the end, I fudged it by using the RunPerlTest script to insert
2366 "use utf8;" explicitly for the UTF-8 tests.
2368 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2369 the end of the subject string, contrary to the documentation and to what
2370 Perl does. This was true of both matching functions. Now it matches only at
2371 the start of the subject and immediately after *internal* newlines.
2373 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2374 a pointer to an int instead of a pointer to an unsigned long int. This
2375 caused problems on 64-bit systems.
2377 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2378 instance of the 'standard' template library not being so standard".
2380 10. There was no check on the number of named subpatterns nor the maximum
2381 length of a subpattern name. The product of these values is used to compute
2382 the size of the memory block for a compiled pattern. By supplying a very
2383 long subpattern name and a large number of named subpatterns, the size
2384 computation could be caused to overflow. This is now prevented by limiting
2385 the length of names to 32 characters, and the number of named subpatterns
2386 to 10,000.
2388 11. Subpatterns that are repeated with specific counts have to be replicated in
2389 the compiled pattern. The size of memory for this was computed from the
2390 length of the subpattern and the repeat count. The latter is limited to
2391 65535, but there was no limit on the former, meaning that integer overflow
2392 could in principle occur. The compiled length of a repeated subpattern is
2393 now limited to 30,000 bytes in order to prevent this.
2395 12. Added the optional facility to have named substrings with the same name.
2397 13. Added the ability to use a named substring as a condition, using the
2398 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2399 are numbers (not recommended). Forward references are permitted.
2401 14. Added forward references in named backreferences (if you see what I mean).
2403 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2404 pattern could run off the end of the subject. For example, the pattern
2405 "(?s)(.{1,5})"8 did this with the subject "ab".
2407 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2408 PCRE_CASELESS was set when matching characters that were quantified with ?
2409 or *.
2411 17. A character class other than a single negated character that had a minimum
2412 but no maximum quantifier - for example [ab]{6,} - was not handled
2413 correctly by pce_dfa_exec(). It would match only one character.
2415 18. A valid (though odd) pattern that looked like a POSIX character
2416 class but used an invalid character after [ (for example [[,abc,]]) caused
2417 pcre_compile() to give the error "Failed: internal error: code overflow" or
2418 in some cases to crash with a glibc free() error. This could even happen if
2419 the pattern terminated after [[ but there just happened to be a sequence of
2420 letters, a binary zero, and a closing ] in the memory that followed.
2422 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2423 over the years. Originally (before any Unicode support), just the bottom 8
2424 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2425 output from "man perlunicode" includes this:
2427 The regular expression compiler produces polymorphic opcodes. That
2428 is, the pattern adapts to the data and automatically switches to
2429 the Unicode character scheme when presented with Unicode data--or
2430 instead uses a traditional byte scheme when presented with byte
2431 data.
2433 Sadly, a wide octal escape does not cause a switch, and in a string with
2434 no other multibyte characters, these octal escapes are treated as before.
2435 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2436 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2437 Unicode string.
2439 I have not perpetrated such confusion in PCRE. Up till now, it took just
2440 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2441 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2442 translate to the appropriate multibyte character.
2444 29. Applied some refactoring to reduce the number of warnings from Microsoft
2445 and Borland compilers. This has included removing the fudge introduced
2446 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2447 a warning about an unused variable.
2449 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2450 characters since release 4.0, because Perl (from release 5.004) does not.
2451 [Or at least, is documented not to: some releases seem to be in conflict
2452 with the documentation.] However, when a pattern was studied with
2453 pcre_study() and all its branches started with \s, PCRE still included VT
2454 as a possible starting character. Of course, this did no harm; it just
2455 caused an unnecessary match attempt.
2457 22. Removed a now-redundant internal flag bit that recorded the fact that case
2458 dependency changed within the pattern. This was once needed for "required
2459 byte" processing, but is no longer used. This recovers a now-scarce options
2460 bit. Also moved the least significant internal flag bit to the most-
2461 significant bit of the word, which was not previously used (hangover from
2462 the days when it was an int rather than a uint) to free up another bit for
2463 the future.
2465 23. Added support for CRLF line endings as well as CR and LF. As well as the
2466 default being selectable at build time, it can now be changed at runtime
2467 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2468 specify that it is scanning data with non-default line endings.
2470 24. Changed the definition of CXXLINK to make it agree with the definition of
2471 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2473 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2474 recursions. This makes a big different to stack usage for some patterns.
2476 26. If a subpattern containing a named recursion or subroutine reference such
2477 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2478 the space required for the compiled pattern went wrong and gave too small a
2479 value. Depending on the environment, this could lead to "Failed: internal
2480 error: code overflow at offset 49" or "glibc detected double free or
2481 corruption" errors.
2483 27. Applied patches from Google (a) to support the new newline modes and (b) to
2484 advance over multibyte UTF-8 characters in GlobalReplace.
2486 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2487 difference for some implementation of PCRE in some Windows version.
2489 29. Added some extra testing facilities to pcretest:
2491 \q<number> in a data line sets the "match limit" value
2492 \Q<number> in a data line sets the "match recursion limt" value
2493 -S <number> sets the stack size, where <number> is in megabytes
2495 The -S option isn't available for Windows.
2498 Version 6.6 06-Feb-06
2499 ---------------------
2501 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2502 in pcreposix.h. I have copied the definition from pcre.h.
2504 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2505 because pcre.h is no longer a built file.
2507 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2508 not normally included in the compiled code.
2511 Version 6.5 01-Feb-06
2512 ---------------------
2514 1. When using the partial match feature with pcre_dfa_exec(), it was not
2515 anchoring the second and subsequent partial matches at the new starting
2516 point. This could lead to incorrect results. For example, with the pattern
2517 /1234/, partially matching against "123" and then "a4" gave a match.
2519 2. Changes to pcregrep:
2521 (a) All non-match returns from pcre_exec() were being treated as failures
2522 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2523 error message is output. Some extra information is given for the
2525 probably the only errors that are likely to be caused by users (by
2526 specifying a regex that has nested indefinite repeats, for instance).
2527 If there are more than 20 of these errors, pcregrep is abandoned.
2529 (b) A binary zero was treated as data while matching, but terminated the
2530 output line if it was written out. This has been fixed: binary zeroes
2531 are now no different to any other data bytes.
2533 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2534 used to set a locale for matching. The --locale=xxxx long option has
2535 been added (no short equivalent) to specify a locale explicitly on the
2536 pcregrep command, overriding the environment variables.
2538 (d) When -B was used with -n, some line numbers in the output were one less
2539 than they should have been.
2541 (e) Added the -o (--only-matching) option.
2543 (f) If -A or -C was used with -c (count only), some lines of context were
2544 accidentally printed for the final match.
2546 (g) Added the -H (--with-filename) option.
2548 (h) The combination of options -rh failed to suppress file names for files
2549 that were found from directory arguments.
2551 (i) Added the -D (--devices) and -d (--directories) options.
2553 (j) Added the -F (--fixed-strings) option.
2555 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2557 (l) Added the --colo(u)r option.
2559 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2560 is not present by default.
2562 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2563 items such as (?R) or (?1), when the recursion could match a number of
2564 alternatives. If it matched one of the alternatives, but subsequently,
2565 outside the recursion, there was a failure, the code tried to back up into
2566 the recursion. However, because of the way PCRE is implemented, this is not
2567 possible, and the result was an incorrect result from the match.
2569 In order to prevent this happening, the specification of recursion has
2570 been changed so that all such subpatterns are automatically treated as
2571 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2573 4. I had overlooked the fact that, in some locales, there are characters for
2574 which isalpha() is true but neither isupper() nor islower() are true. In
2575 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2576 and ordfeminine) are like this. This affected the treatment of \w and \W
2577 when they appeared in character classes, but not when they appeared outside
2578 a character class. The bit map for "word" characters is now created
2579 separately from the results of isalnum() instead of just taking it from the
2580 upper, lower, and digit maps. (Plus the underscore character, of course.)
2582 5. The above bug also affected the handling of POSIX character classes such as
2583 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2584 permanent tables. Instead, the bit maps for such a class were previously
2585 created as the appropriate unions of the upper, lower, and digit bitmaps.
2586 Now they are created by subtraction from the [[:word:]] class, which has
2587 its own bitmap.
2589 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2590 It is created by subtracting the vertical space characters (\x09, \x0a,
2591 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2592 subtraction was done in the overall bitmap for a character class, meaning
2593 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2594 be recognized. This bug has been fixed.
2596 7. Patches from the folks at Google:
2598 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2599 real life, but is still worth protecting against".
2601 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2602 regular expressions".
2604 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2605 have it.
2607 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2608 "configure" and the latter not, in order to fix a problem somebody had
2609 with compiling the Arg class on HP-UX.
2611 (e) Improve the error-handling of the C++ wrapper a little bit.
2613 (f) New tests for checking recursion limiting.
2615 8. The pcre_memmove() function, which is used only if the environment does not
2616 have a standard memmove() function (and is therefore rarely compiled),
2617 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2618 returning a result (though PCRE never actually uses the result).
2620 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2621 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2622 returned instead of calling malloc() with an overflowing number that would
2623 most likely cause subsequent chaos.
2625 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2627 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2628 with this option is matched, the nmatch and pmatch options of regexec() are
2629 ignored.
2631 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2632 provided in case anyone wants to the the POSIX interface with UTF-8
2633 strings.
2635 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2636 C++ linking (needed for some HP-UX environments).
2638 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2639 (unused parameter) and in the pcre_printint() function (omitted "default"
2640 switch label when the default is to do nothing).
2642 15. Added some code to make it possible, when PCRE is compiled as a C++
2643 library, to replace subject pointers for pcre_exec() with a smart pointer
2644 class, thus making it possible to process discontinuous strings.
2646 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2647 much the same function. They were added by different people who were trying
2648 to make PCRE easy to compile on non-Unix systems. It has been suggested
2649 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2650 for compiling on Windows systems. I have therefore replaced it with
2651 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2652 defaults to "extern" for C or "extern C" for C++, which works fine on
2653 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2654 SCOPE with something explicit in config.h. In addition:
2656 (a) pcreposix.h still had just "extern" instead of either of these macros;
2657 I have replaced it with PCRE_DATA_SCOPE.
2659 (b) Functions such as _pcre_xclass(), which are internal to the library,
2660 but external in the C sense, all had PCRE_EXPORT in their definitions.
2661 This is apparently wrong for the Windows case, so I have removed it.
2662 (It makes no difference on Unix-like systems.)
2664 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2665 of recursive calls to match(). This is different to MATCH_LIMIT because
2666 that limits the total number of calls to match(), not all of which increase
2667 the depth of recursion. Limiting the recursion depth limits the amount of
2668 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2669 when PCRE is compiled, and changed at run time. A patch from Google adds
2670 this functionality to the C++ interface.
2672 18. Changes to the handling of Unicode character properties:
2674 (a) Updated the table to Unicode 4.1.0.
2676 (b) Recognize characters that are not in the table as "Cn" (undefined).
2678 (c) I revised the way the table is implemented to a much improved format
2679 which includes recognition of ranges. It now supports the ranges that
2680 are defined in UnicodeData.txt, and it also amalgamates other
2681 characters into ranges. This has reduced the number of entries in the
2682 table from around 16,000 to around 3,000, thus reducing its size
2683 considerably. I realized I did not need to use a tree structure after
2684 all - a binary chop search is just as efficient. Having reduced the
2685 number of entries, I extended their size from 6 bytes to 8 bytes to
2686 allow for more data.
2688 (d) Added support for Unicode script names via properties such as \p{Han}.
2690 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2691 matching that character.
2693 20. When matching a repeated Unicode property with a minimum greater than zero,
2694 (for example \pL{2,}), PCRE could look past the end of the subject if it
2695 reached it while seeking the minimum number of characters. This could
2696 happen only if some of the characters were more than one byte long, because
2697 there is a check for at least the minimum number of bytes.
2699 21. Refactored the implementation of \p and \P so as to be more general, to
2700 allow for more different types of property in future. This has changed the
2701 compiled form incompatibly. Anybody with saved compiled patterns that use
2702 \p or \P will have to recompile them.
2704 22. Added "Any" and "L&" to the supported property types.
2706 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2707 but give a compile time error if the value is greater than 0xff.
2709 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2710 accidentally not being installed or uninstalled.
2712 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2713 made were to insert the current release number. This seemed silly, because
2714 it made things harder for people building PCRE on systems that don't run
2715 "configure". I have turned pcre.h into a distributed file, no longer built
2716 by "configure", with the version identification directly included. There is
2717 no longer a pcre.h.in file.
2719 However, this change necessitated a change to the pcre-config script as
2720 well. It is built from pcre-config.in, and one of the substitutions was the
2721 release number. I have updated configure.ac so that ./configure now finds
2722 the release number by grepping pcre.h.
2724 26. Added the ability to run the tests under valgrind.
2727 Version 6.4 05-Sep-05
2728 ---------------------
2730 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2731 "--" to be printed when multiple files were scanned, even when none of the
2732 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2733 consider it to be a bug, and have restored the previous behaviour.
2735 2. A couple of code tidies to get rid of compiler warnings.
2737 3. The pcretest program used to cheat by referring to symbols in the library
2738 whose names begin with _pcre_. These are internal symbols that are not
2739 really supposed to be visible externally, and in some environments it is
2740 possible to suppress them. The cheating is now confined to including
2741 certain files from the library's source, which is a bit cleaner.
2743 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2744 file's purpose clearer.
2746 5. Reorganized pcre_ucp_findchar().
2749 Version 6.3 15-Aug-05
2750 ---------------------
2752 1. The file libpcre.pc.in did not have general read permission in the tarball.
2754 2. There were some problems when building without C++ support:
2756 (a) If C++ support was not built, "make install" and "make test" still
2757 tried to test it.
2759 (b) There were problems when the value of CXX was explicitly set. Some
2760 changes have been made to try to fix these, and ...
2762 (c) --disable-cpp can now be used to explicitly disable C++ support.
2764 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2765 backslash in a target when C++ was disabled. This confuses some
2766 versions of "make", apparently. Using an intermediate variable solves
2767 this. (Same for CPP_LOBJ.)
2769 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2770 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2771 necessary on certain architectures.
2773 4. Added a setting of -export-symbols-regex to the link command to remove
2774 those symbols that are exported in the C sense, but actually are local
2775 within the library, and not documented. Their names all begin with
2776 "_pcre_". This is not a perfect job, because (a) we have to except some
2777 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2778 available (and never for static libraries). I have made a note to try to
2779 find a way round (a) in the future.
2782 Version 6.2 01-Aug-05
2783 ---------------------
2785 1. There was no test for integer overflow of quantifier values. A construction
2786 such as {1111111111111111} would give undefined results. What is worse, if
2787 a minimum quantifier for a parenthesized subpattern overflowed and became
2788 negative, the calculation of the memory size went wrong. This could have
2789 led to memory overwriting.
2791 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2793 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2794 operating environments where this matters.
2796 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2797 PCRE options from within the C++ wrapper.
2799 5. Named capturing subpatterns were not being correctly counted when a pattern
2800 was compiled. This caused two problems: (a) If there were more than 100
2801 such subpatterns, the calculation of the memory needed for the whole
2802 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2803 back references of the form \12, where the number was greater than 9, were
2804 not recognized as back references, even though there were sufficient
2805 previous subpatterns.
2807 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2808 versions of gcc, e.g. 2.95.4.
2811 Version 6.1 21-Jun-05
2812 ---------------------
2814 1. There was one reference to the variable "posix" in pcretest.c that was not
2815 surrounded by "#if !defined NOPOSIX".
2817 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2818 the cross-check on the old pcre_info() function, for the benefit of the
2819 cut-down version of PCRE that is currently imported into Exim.
2821 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2822 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2823 patterns that start (?i) but I don't think that matters. The use of (?i) is
2824 just an example; this all applies to the other options as well.
2826 4. Since libtool seems to echo the compile commands it is issuing, the output
2827 from "make" can be reduced a bit by putting "@" in front of each libtool
2828 compile command.
2830 5. Patch from the folks at Google for configure.in to be a bit more thorough
2831 in checking for a suitable C++ installation before trying to compile the
2832 C++ stuff. This should fix a reported problem when a compiler was present,
2833 but no suitable headers.
2835 6. The man pages all had just "PCRE" as their title. I have changed them to
2836 be the relevant file name. I have also arranged that these names are
2837 retained in the file doc/pcre.txt, which is a concatenation in text format
2838 of all the man pages except the little individual ones for each function.
2840 7. The NON-UNIX-USE file had not been updated for the different set of source
2841 files that come with release 6. I also added a few comments about the C++
2842 wrapper.
2845 Version 6.0 07-Jun-05
2846 ---------------------
2848 1. Some minor internal re-organization to help with my DFA experiments.
2850 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2851 didn't matter for the library itself when fully configured, but did matter
2852 when compiling without UCP support, or within Exim, where the ucp files are
2853 not imported.
2855 3. Refactoring of the library code to split up the various functions into
2856 different source modules. The addition of the new DFA matching code (see
2857 below) to a single monolithic source would have made it really too
2858 unwieldy, quite apart from causing all the code to be include in a
2859 statically linked application, when only some functions are used. This is
2860 relevant even without the DFA addition now that patterns can be compiled in
2861 one application and matched in another.
2863 The downside of splitting up is that there have to be some external
2864 functions and data tables that are used internally in different modules of
2865 the library but which are not part of the API. These have all had their
2866 names changed to start with "_pcre_" so that they are unlikely to clash
2867 with other external names.
2869 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2870 a different (DFA) algorithm. Although it is slower than the original
2871 function, it does have some advantages for certain types of matching
2872 problem.
2874 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2875 including restarting after a partial match.
2877 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2878 defined when compiling for Windows was sent to me. I have put it into the
2879 code, though I have no means of testing or verifying it.
2881 7. Added the pcre_refcount() auxiliary function.
2883 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2884 match before or at the first newline in the subject string. In pcretest,
2885 the /f option on a pattern can be used to set this.
2887 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2888 would behave wrongly. This has been present in PCRE since release 4.0.
2890 10. A number of changes to the pcregrep command:
2892 (a) Refactored how -x works; insert ^(...)$ instead of setting
2893 PCRE_ANCHORED and checking the length, in preparation for adding
2894 something similar for -w.
2896 (b) Added the -w (match as a word) option.
2898 (c) Refactored the way lines are read and buffered so as to have more
2899 than one at a time available.
2901 (d) Implemented a pcregrep test script.
2903 (e) Added the -M (multiline match) option. This allows patterns to match
2904 over several lines of the subject. The buffering ensures that at least
2905 8K, or the rest of the document (whichever is the shorter) is available
2906 for matching (and similarly the previous 8K for lookbehind assertions).
2908 (f) Changed the --help output so that it now says
2910 -w, --word-regex(p)
2912 instead of two lines, one with "regex" and the other with "regexp"
2913 because that confused at least one person since the short forms are the
2914 same. (This required a bit of code, as the output is generated
2915 automatically from a table. It wasn't just a text change.)
2917 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2918 option but starts with a hyphen. Could be a pattern or a path name
2919 starting with a hyphen, for instance.
2921 (h) "-" can be given as a file name to represent stdin.
2923 (i) When file names are being printed, "(standard input)" is used for
2924 the standard input, for compatibility with GNU grep. Previously
2925 "<stdin>" was used.
2927 (j) The option --label=xxx can be used to supply a name to be used for
2928 stdin when file names are being printed. There is no short form.
2930 (k) Re-factored the options decoding logic because we are going to add
2931 two more options that take data. Such options can now be given in four
2932 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2934 (l) Added the -A, -B, and -C options for requesting that lines of context
2935 around matches be printed.
2937 (m) Added the -L option to print the names of files that do not contain
2938 any matching lines, that is, the complement of -l.
2940 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2941 continue to scan other files.
2943 (o) The -s option was incorrectly implemented. For compatibility with other
2944 greps, it now suppresses the error message for a non-existent or non-
2945 accessible file (but not the return code). There is a new option called
2946 -q that suppresses the output of matching lines, which was what -s was
2947 previously doing.
2949 (p) Added --include and --exclude options to specify files for inclusion
2950 and exclusion when recursing.
2952 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2953 Hopefully, it now does.
2955 12. Missing cast in pcre_study().
2957 13. Added an "uninstall" target to the makefile.
2959 14. Replaced "extern" in the function prototypes in Makefile.in with
2960 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2961 world, but is set differently for Windows.
2963 15. Added a second compiling function called pcre_compile2(). The only
2964 difference is that it has an extra argument, which is a pointer to an
2965 integer error code. When there is a compile-time failure, this is set
2966 non-zero, in addition to the error test pointer being set to point to an
2967 error message. The new argument may be NULL if no error number is required
2968 (but then you may as well call pcre_compile(), which is now just a
2969 wrapper). This facility is provided because some applications need a
2970 numeric error indication, but it has also enabled me to tidy up the way
2971 compile-time errors are handled in the POSIX wrapper.
2973 16. Added VPATH=.libs to the makefile; this should help when building with one
2974 prefix path and installing with another. (Or so I'm told by someone who
2975 knows more about this stuff than I do.)
2977 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2978 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2979 match everything, including newlines. This is not POSIX-compatible, but
2980 somebody wanted the feature. From pcretest it can be activated by using
2981 both the P and the s flags.
2983 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2985 19. libpcre.pc was being incorrectly installed as executable.
2987 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2988 it now also looks for '\r' so that it will work unmodified on Windows.
2990 21. Added Google's contributed C++ wrapper to the distribution.
2992 22. Added some untidy missing memory free() calls in pcretest, to keep
2993 Electric Fence happy when testing.
2997 Version 5.0 13-Sep-04
2998 ---------------------
3000 1. Internal change: literal characters are no longer packed up into items
3001 containing multiple characters in a single byte-string. Each character
3002 is now matched using a separate opcode. However, there may be more than one
3003 byte in the character in UTF-8 mode.
3005 2. The pcre_callout_block structure has two new fields: pattern_position and
3006 next_item_length. These contain the offset in the pattern to the next match
3007 item, and its length, respectively.
3009 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3010 insertion of callouts before each pattern item. Added the /C option to
3011 pcretest to make use of this.
3013 4. On the advice of a Windows user, the lines
3015 #if defined(_WIN32) || defined(WIN32)
3016 _setmode( _fileno( stdout ), 0x8000 );
3017 #endif /* defined(_WIN32) || defined(WIN32) */
3019 have been added to the source of pcretest. This apparently does useful
3020 magic in relation to line terminators.
3022 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3023 for the benefit of those environments where the "b" makes a difference.
3025 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3026 to know about it. I have put a hack into configure.in that adds in code
3027 to set GCC=yes if CC=icc. This seems to end up at a point in the
3028 generated configure script that is early enough to affect the setting of
3029 compiler options, which is what is needed, but I have no means of testing
3030 whether it really works. (The user who reported this had patched the
3031 generated configure script, which of course I cannot do.)
3033 LATER: After change 22 below (new libtool files), the configure script
3034 seems to know about icc (and also ecc). Therefore, I have commented out
3035 this hack in configure.in.
3037 7. Added support for pkg-config (2 patches were sent in).
3039 8. Negated POSIX character classes that used a combination of internal tables
3040 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3041 [[:^ascii]]. Typically, they would match almost any characters. The other
3042 POSIX classes were not broken in this way.
3044 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3045 to find the match, as PCRE was deluded into thinking that the match had to
3046 start at the start point or following a newline. The same bug applied to
3047 patterns with negative forward assertions or any backward assertions
3048 preceding ".*" at the start, unless the pattern required a fixed first
3049 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3051 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3052 starting at the last subject character, bytes beyond the end of the subject
3053 string were read.
3055 11. Renamed the variable "class" as "classbits" to make life easier for C++
3056 users. (Previously there was a macro definition, but it apparently wasn't
3057 enough.)
3059 12. Added the new field "tables" to the extra data so that tables can be passed
3060 in at exec time, or the internal tables can be re-selected. This allows
3061 a compiled regex to be saved and re-used at a later time by a different
3062 program that might have everything at different addresses.
3064 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3065 -R library as well as a -L library.
3067 14. The debugging options of pcretest (-d on the command line or D on a
3068 pattern) showed incorrect output for anything following an extended class
3069 that contained multibyte characters and which was followed by a quantifier.
3071 15. Added optional support for general category Unicode character properties
3072 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3073 support. It adds about 90K to the size of the library. The meanings of the
3074 inbuilt class escapes such as \d and \s have NOT been changed.
3076 16. Updated pcredemo.c to include calls to free() to release the memory for the
3077 compiled pattern.
3079 17. The generated file chartables.c was being created in the source directory
3080 instead of in the building directory. This caused the build to fail if the
3081 source directory was different from the building directory, and was
3082 read-only.
3084 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3085 file. No doubt somebody will tell me if they don't make sense... Also added
3086 Dan Mooney's comments about building on OpenVMS.
3088 19. Added support for partial matching via the PCRE_PARTIAL option for
3089 pcre_exec() and the \P data escape in pcretest.
3091 20. Extended pcretest with 3 new pattern features:
3093 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3094 write the compiled pattern to the file whose name is "rest-of-line".
3095 This is a straight binary dump of the data, with the saved pointer to
3096 the character tables forced to be NULL. The study data, if any, is
3097 written too. After writing, pcretest reads a new pattern.
3099 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3100 compiled pattern from the given file. There must not be any
3101 occurrences of "<" in the file name (pretty unlikely); if there are,
3102 pcretest will instead treat the initial "<" as a pattern delimiter.
3103 After reading in the pattern, pcretest goes on to read data lines as
3104 usual.
3106 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3107 and 16-bit fields in a compiled pattern, to simulate a pattern that
3108 was compiled on a host of opposite endianness.
3110 21. The pcre-exec() function can now cope with patterns that were compiled on
3111 hosts of opposite endianness, with this restriction:
3113 As for any compiled expression that is saved and used later, the tables
3114 pointer field cannot be preserved; the extra_data field in the arguments
3115 to pcre_exec() should be used to pass in a tables address if a value
3116 other than the default internal tables were used at compile time.
3118 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3119 now diagnosed as an error. Previously, most of the time, a negative number
3120 would have been treated as zero, but if in addition "ovector" was passed as
3121 NULL, a crash could occur.
3123 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3124 new versions from the libtool 1.5 distribution (the last one is a copy of
3125 a file called libtool.m4). This seems to have fixed the need to patch
3126 "configure" to support Darwin 1.3 (which I used to do). However, I still
3127 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3128 workstation).
3130 24. Changed the PCRE licence to be the more standard "BSD" licence.
3133 Version 4.5 01-Dec-03
3134 ---------------------
3136 1. There has been some re-arrangement of the code for the match() function so
3137 that it can be compiled in a version that does not call itself recursively.
3138 Instead, it keeps those local variables that need separate instances for
3139 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3140 needs to "recurse". Keeping track of where control must go is done by means
3141 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3142 hide most of the details from the main code, and operates only if
3143 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3144 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3145 operating.
3147 To make it easier for callers to provide specially tailored get/free
3148 functions for this usage, two new functions, pcre_stack_malloc, and
3149 pcre_stack_free, are used. They are always called in strict stacking order,
3150 and the size of block requested is always the same.
3152 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3153 PCRE has been compiled to use the stack or the heap for recursion. The
3154 -C option of pcretest uses this to show which version is compiled.
3156 A new data escape \S, is added to pcretest; it causes the amounts of store
3157 obtained and freed by both kinds of malloc/free at match time to be added
3158 to the output.
3160 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3161 what's available on my current Linux desktop machine.
3163 3. When matching a UTF-8 string, the test for a valid string at the start has
3164 been extended. If start_offset is not zero, PCRE now checks that it points
3165 to a byte that is the start of a UTF-8 character. If not, it returns
3166 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3167 this is necessary because there may be backward assertions in the pattern.
3168 When matching the same subject several times, it may save resources to use
3169 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3171 4. The code for checking the validity of UTF-8 strings has been tightened so
3172 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3173 containing "overlong sequences".
3175 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3176 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3177 should have been "&", but it just so happened that all the cases this let
3178 through by mistake were picked up later in the function.
3180 6. I had used a variable called "isblank" - this is a C99 function, causing
3181 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3183 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3184 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3185 so the version is shown; (c) stop "make test" echoing "./RunTest".
3187 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3189 9. The prototype for memmove() for systems that don't have it was using
3190 size_t, but the inclusion of the header that defines size_t was later. I've
3191 moved the #includes for the C headers earlier to avoid this.
3193 10. Added some adjustments to the code to make it easier to compiler on certain
3194 special systems:
3196 (a) Some "const" qualifiers were missing.
3197 (b) Added the macro EXPORT before all exported functions; by default this
3198 is defined to be empty.
3199 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3200 that it reads its output file name as an argument instead of writing
3201 to the standard output and assuming this can be redirected.
3203 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3204 class containing characters with values greater than 255, PCRE compilation
3205 went into a loop.
3207 12. A recursive reference to a subpattern that was within another subpattern
3208 that had a minimum quantifier of zero caused PCRE to crash. For example,
3209 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3210 recursion. If the recursively-called subpattern itself had a zero repeat,
3211 that was OK.
3213 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3214 buffer into which it was copied (for escape processing) was still set at
3215 1024, so long lines caused crashes.
3217 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3218 "internal error: code overflow...". This applied to any character class
3219 that was followed by a possessive quantifier.
3221 15. Modified the Makefile to add libpcre.la as a prerequisite for
3222 libpcreposix.la because I was told this is needed for a parallel build to
3223 work.
3225 16. If a pattern that contained .* following optional items at the start was
3226 studied, the wrong optimizing data was generated, leading to matching
3227 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3228 matching string must start with a or b or c. The correct conclusion for
3229 this pattern is that a match can start with any character.
3232 Version 4.4 13-Aug-03
3233 ---------------------
3235 1. In UTF-8 mode, a character class containing characters with values between
3236 127 and 255 was not handled correctly if the compiled pattern was studied.
3237 In fixing this, I have also improved the studying algorithm for such
3238 classes (slightly).
3240 2. Three internal functions had redundant arguments passed to them. Removal
3241 might give a very teeny performance improvement.
3243 3. Documentation bug: the value of the capture_top field in a callout is *one
3244 more than* the number of the hightest numbered captured substring.
3246 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3247 in incorrectly linking with a previously installed version. They now link
3248 explicitly with libpcre.la.
3250 5. configure.in no longer needs to recognize Cygwin specially.
3252 6. A problem in pcre.in for Windows platforms is fixed.
3254 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3255 pcretest, it used to include the size of the study block as part of its
3256 output. Unfortunately, the structure contains a field that has a different
3257 size on different hardware architectures. This meant that the tests that
3258 showed this size failed. As the block is currently always of a fixed size,
3259 this information isn't actually particularly useful in pcretest output, so
3260 I have just removed it.
3262 8. Three pre-processor statements accidentally did not start in column 1.
3263 Sadly, there are *still* compilers around that complain, even though
3264 standard C has not required this for well over a decade. Sigh.
3266 9. In pcretest, the code for checking callouts passed small integers in the
3267 callout_data field, which is a void * field. However, some picky compilers
3268 complained about the casts involved for this on 64-bit systems. Now
3269 pcretest passes the address of the small integer instead, which should get
3270 rid of the warnings.
3272 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3273 both compile and run time, and gives an error if an invalid UTF-8 sequence
3274 is found. There is a option for disabling this check in cases where the
3275 string is known to be correct and/or the maximum performance is wanted.
3277 11. In response to a bug report, I changed one line in Makefile.in from
3279 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3280 to
3281 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3283 to look similar to other lines, but I have no way of telling whether this
3284 is the right thing to do, as I do not use Windows. No doubt I'll get told
3285 if it's wrong...
3288 Version 4.3 21-May-03
3289 ---------------------
3291 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3292 Makefile.
3294 2. Some refactoring to improve the quality of the code:
3296 (i) The utf8_table... variables are now declared "const".
3298 (ii) The code for \cx, which used the "case flipping" table to upper case
3299 lower case letters, now just substracts 32. This is ASCII-specific,
3300 but the whole concept of \cx is ASCII-specific, so it seems
3301 reasonable.
3303 (iii) PCRE was using its character types table to recognize decimal and
3304 hexadecimal digits in the pattern. This is silly, because it handles
3305 only 0-9, a-f, and A-F, but the character types table is locale-
3306 specific, which means strange things might happen. A private
3307 table is now used for this - though it costs 256 bytes, a table is
3308 much faster than multiple explicit tests. Of course, the standard
3309 character types table is still used for matching digits in subject
3310 strings against \d.
3312 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3313 ending in _t are). So I've renamed it as ESC_tee.
3315 3. The first argument for regexec() in the POSIX wrapper should have been
3316 defined as "const".
3318 4. Changed pcretest to use malloc() for its buffers so that they can be
3319 Electric Fenced for debugging.
3321 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3322 to read one or more bytes before the start of the subject string. Often this
3323 had no effect on PCRE's behaviour, but in some circumstances it could
3324 provoke a segmentation fault.
3326 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3327 to try to read one or more bytes before the start of the subject string.
3329 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3330 UTF-8 support could misbehave in various ways if the subject string
3331 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3332 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3333 back over UTF-8 characters.)
3336 Version 4.2 14-Apr-03
3337 ---------------------
3339 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3341 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3342 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3343 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3344 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3345 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3347 Note: automatic setting of the BUILD variables is not yet working
3348 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3349 compile-time but not at link-time
3350 [LINK]: use for linking executables only
3351 make different versions for Windows and non-Windows
3352 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3353 libraries
3354 [LINK_FOR_BUILD]: new variable
3355 [OBJEXT]: use throughout
3356 [EXEEXT]: use throughout
3357 <winshared>: new target
3358 <wininstall>: new target
3359 <dftables.o>: use native compiler
3360 <dftables>: use native linker
3361 <install>: handle Windows platform correctly
3362 <clean>: ditto
3363 <check>: ditto
3364 copy DLL to top builddir before testing
3366 As part of these changes, -no-undefined was removed again. This was reported
3367 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3368 in any case.
3370 3. Some tidies to get rid of compiler warnings:
3372 . In the match_data structure, match_limit was an unsigned long int, whereas
3373 match_call_count was an int. I've made them both unsigned long ints.
3375 . In pcretest the fact that a const uschar * doesn't automatically cast to
3376 a void * provoked a warning.
3378 . Turning on some more compiler warnings threw up some "shadow" variables
3379 and a few more missing casts.
3381 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3382 option, a class that contained a single character with a value between 128
3383 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3385 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3386 option, a class that contained several characters, but with at least one
3387 whose value was between 128 and 255 caused PCRE to crash.
3390 Version 4.1 12-Mar-03
3391 ---------------------
3393 1. Compiling with gcc -pedantic found a couple of places where casts were
3394 needed, and a string in dftables.c that was longer than standard compilers are
3395 required to support.
3397 2. Compiling with Sun's compiler found a few more places where the code could
3398 be tidied up in order to avoid warnings.
3400 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3401 first of these names is deprecated in the latest Autoconf in favour of the name
3402 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3403 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3404 analogy I have changed it to CFLAGS_FOR_BUILD.
3406 4. Added -no-undefined to the linking command in the Makefile, because this is
3407 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3408 linking step for the pcreposix library.
3410 5. PCRE was failing to diagnose the case of two named groups with the same
3411 name.
3413 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3414 literal character that is needed in the subject for a match, and scans along to
3415 ensure that it is present before embarking on the full matching process. This
3416 saves time in cases of nested unlimited repeats that are never going to match.
3417 Problem: the scan can take a lot of time if the subject is very long (e.g.
3418 megabytes), thus penalizing straightforward matches. It is now done only if the
3419 amount of subject to be scanned is less than 1000 bytes.
3421 7. A lesser problem with the same optimization is that it was recording the
3422 first character of an anchored pattern as "needed", thus provoking a search
3423 right along the subject, even when the first match of the pattern was going to
3424 fail. The "needed" character is now not set for anchored patterns, unless it
3425 follows something in the pattern that is of non-fixed length. Thus, it still
3426 fulfils its original purpose of finding quick non-matches in cases of nested
3427 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3430 Version 4.0 17-Feb-03
3431 ---------------------
3433 1. If a comment in an extended regex that started immediately after a meta-item
3434 extended to the end of string, PCRE compiled incorrect data. This could lead to
3435 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3437 2. Moved to autoconf 2.53 and libtool 1.4.2.
3439 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3440 the special perltest8 script is no longer needed - all the tests can be run
3441 from a single perltest script.
3443 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3444 by \s. It has now been removed in PCRE. This means it isn't recognized as
3445 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3446 class [:space:] *does* include VT, thereby creating a mess.
3448 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3449 space and tab.
3451 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3452 its new features into the main test script, reducing the number of scripts.
3454 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3455 were backward compatible, and made the (?i) apply to the whole pattern, as if
3456 /i were given. Now it behaves more logically, and applies the option setting
3457 only to what follows. PCRE has been changed to follow suit. However, if it
3458 finds options settings right at the start of the pattern, it extracts them into
3459 the global options, as before. Thus, they show up in the info data.
3461 8. Added support for the \Q...\E escape sequence. Characters in between are
3462 treated as literals. This is slightly different from Perl in that $ and @ are
3463 also handled as literals inside the quotes. In Perl, they will cause variable
3464 interpolation. Note the following examples:
3466 Pattern PCRE matches Perl matches
3468 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3469 \Qabc\$xyz\E abc\$xyz abc\$xyz
3470 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3472 For compatibility with Perl, \Q...\E sequences are recognized inside character
3473 classes as well as outside them.
3475 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3476 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3477 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3478 signed/unsigned warnings.
3480 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3481 option for pcretest, so I've replaced it by a simple function that does just
3482 that job.
3484 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3485 "pcregrep -".
3487 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3488 Java package. This provides some syntactic sugar for simple cases of what my
3489 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3490 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3491 item, you can use this simplified notation. Note that only makes sense with
3492 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3493 greediness, whatever the setting of the PCRE_UNGREEDY option.
3495 13. A change of greediness default within a pattern was not taking effect at
3496 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3497 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3498 was abstracted outside.
3500 14. PCRE now supports the \G assertion. It is true when the current matching
3501 position is at the start point of the match. This differs from \A when the
3502 starting offset is non-zero. Used with the /g option of pcretest (or similar
3503 code), it works in the same way as it does for Perl's /g option. If all
3504 alternatives of a regex begin with \G, the expression is anchored to the start
3505 match position, and the "anchored" flag is set in the compiled expression.
3507 15. Some bugs concerning the handling of certain option changes within patterns
3508 have been fixed. These applied to options other than (?ims). For example,
3509 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3510 been the other way round. Some of this was related to change 7 above.
3512 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3513 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3514 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3515 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3517 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3518 mode. Unlike ".", it always matches newline, whatever the setting of
3519 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3520 assertions. Perl allows it, but it doesn't (in general) work because it can't
3521 calculate the length of the lookbehind. At least, that's the case for Perl
3522 5.8.0 - I've been told they are going to document that it doesn't work in
3523 future.
3525 18. Added an error diagnosis for escapes that PCRE does not support: these are
3526 \L, \l, \N, \P, \p, \U, \u, and \X.
3528 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3529 reading past the end of the pattern in cases such as /[abcd/.
3531 20. PCRE was getting more memory than necessary for patterns with classes that
3532 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3534 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3535 compiling PCRE for use with Virtual Pascal.
3537 22. Small fix to the Makefile to make it work properly if the build is done
3538 outside the source tree.
3540 23. Added a new extension: a condition to go with recursion. If a conditional
3541 subpattern starts with (?(R) the "true" branch is used if recursion has
3542 happened, whereas the "false" branch is used only at the top level.
3544 24. When there was a very long string of literal characters (over 255 bytes
3545 without UTF support, over 250 bytes with UTF support), the computation of how
3546 much memory was required could be incorrect, leading to segfaults or other
3547 strange effects.
3549 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3550 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3551 there was a subsequent back reference to those brackets. This meant that, for
3552 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3553 possible to check for precisely this case. All we can do is abandon the
3554 optimization if .* occurs inside capturing brackets when there are any back
3555 references whatsoever. (See below for a better fix that came later.)
3557 26. The handling of the optimization for finding the first character of a
3558 non-anchored pattern, and for finding a character that is required later in the
3559 match were failing in some cases. This didn't break the matching; it just
3560 failed to optimize when it could. The way this is done has been re-implemented.
3562 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3564 28. Added a new feature that provides some of the functionality that Perl
3565 provides with (?{...}). The facility is termed a "callout". The way it is done
3566 in PCRE is for the caller to provide an optional function, by setting
3567 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3568 global variable. By default it is unset, which disables all calling out. To get
3569 the function called, the regex must include (?C) at appropriate points. This
3570 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3571 This provides a means of identifying different callout points. When PCRE
3572 reaches such a point in the regex, if pcre_callout has been set, the external
3573 function is called. It is provided with data in a structure called
3574 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3575 matching continues; if it returns a non-zero value, the match at the current
3576 point fails. However, backtracking will occur if possible. [This was changed
3577 later and other features added - see item 49 below.]
3579 29. pcretest is upgraded to test the callout functionality. It provides a
3580 callout function that displays information. By default, it shows the start of
3581 the match and the current position in the text. There are some new data escapes
3582 to vary what happens:
3584 \C+ in addition, show current contents of captured substrings
3585 \C- do not supply a callout function
3586 \C!n return 1 when callout number n is reached
3587 \C!n!m return 1 when callout number n is reached for the mth time
3589 30. If pcregrep was called with the -l option and just a single file name, it
3590 output "<stdin>" if a match was found, instead of the file name.
3592 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3593 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3594 pcre_exec(). This saves a malloc/free per call. The default value of
3595 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3596 when configuring.
3598 32. The default maximum size of a compiled pattern is 64K. There have been a
3599 few cases of people hitting this limit. The code now uses macros to handle the
3600 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3601 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3602 configuring. Tests 2 and 5 work only with 2-byte links because they output
3603 debugging information about compiled patterns.
3605 33. Internal code re-arrangements:
3607 (a) Moved the debugging function for printing out a compiled regex into
3608 its own source file (printint.c) and used #include to pull it into
3609 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3610 separate copies.
3612 (b) Defined the list of op-code names for debugging as a macro in
3613 internal.h so that it is next to the definition of the opcodes.
3615 (c) Defined a table of op-code lengths for simpler skipping along compiled
3616 code. This is again a macro in internal.h so that it is next to the
3617 definition of the opcodes.
3619 34. Added support for recursive calls to individual subpatterns, along the
3620 lines of Robin Houston's patch (but implemented somewhat differently).
3622 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3623 allow it to read and process whole directories in Win32. This code was
3624 contributed by Lionel Fourquaux; it has not been tested by me.
3626 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3627 used to name a group. Names consist of alphanumerics and underscores, and must
3628 be unique. Back references use the syntax (?P=name) and recursive calls use
3629 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3630 numbers. The function pcre_fullinfo() can be used after compilation to extract
3631 a name/number map. There are three relevant calls:
3633 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3634 PCRE_INFO_NAMECOUNT yields the number of entries
3635 PCRE_INFO_NAMETABLE yields a pointer to the map.
3637 The map is a vector of fixed-size entries. The size of each entry depends on
3638 the length of the longest name used. The first two bytes of each entry are the
3639 group number, most significant byte first. There follows the corresponding
3640 name, zero terminated. The names are in alphabetical order.
3642 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3643 case instead of 255. Making it the same both with and without UTF-8 support
3644 means that the same test output works with both.
3646 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3647 calling malloc() with a zero argument.
3649 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3650 optimization. I've improved things by keeping a bitmap of backreferences with
3651 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3652 fact referenced, the optimization can be applied. It is unlikely that a
3653 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3654 the match to follow \n) will appear inside brackets with a number greater than
3655 31, but if it does, any back reference > 31 suppresses the optimization.
3657 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3658 of disabling numbered capturing parentheses. Any opening parenthesis that is
3659 not followed by ? behaves as if it were followed by ?: but named parentheses
3660 can still be used for capturing (and they will acquire numbers in the usual
3661 way).
3663 41. Redesigned the return codes from the match() function into yes/no/error so
3664 that errors can be passed back from deep inside the nested calls. A malloc
3665 failure while inside a recursive subpattern call now causes the
3666 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3668 42. It is now possible to set a limit on the number of times the match()
3669 function is called in a call to pcre_exec(). This facility makes it possible to
3670 limit the amount of recursion and backtracking, though not in a directly
3671 obvious way, because the match() function is used in a number of different
3672 circumstances. The count starts from zero for each position in the subject
3673 string (for non-anchored patterns). The default limit is, for compatibility, a
3674 large number, namely 10 000 000. You can change this in two ways:
3676 (a) When configuring PCRE before making, you can use --with-match-limit=n
3677 to set a default value for the compiled library.
3679 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3680 a different value is set. See 45 below.
3682 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3684 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3685 of things that can be changed at compile time. The first argument specifies
3686 what is wanted and the second points to where the information is to be placed.
3687 The current list of available information is:
3691 The output is an integer that is set to one if UTF-8 support is available;
3692 otherwise it is set to zero.
3696 The output is an integer that it set to the value of the code that is used for
3697 newline. It is either LF (10) or CR (13).
3701 The output is an integer that contains the number of bytes used for internal
3702 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3706 The output is an integer that contains the threshold above which the POSIX
3707 interface uses malloc() for output vectors. See item 31 above.
3711 The output is an unsigned integer that contains the default limit of the number
3712 of match() calls in a pcre_exec() execution. See 42 above.
3714 44. pcretest has been upgraded by the addition of the -C option. This causes it
3715 to extract all the available output from the new pcre_config() function, and to
3716 output it. The program then exits immediately.
3718 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3719 order to support additional features. One way would have been to define
3720 pcre_exec2() (for example) with extra arguments, but this would not have been
3721 extensible, and would also have required all calls to the original function to
3722 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3723 is used for passing in "extra" data from pcre_study().
3725 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3726 contains the following fields:
3728 flags a bitmap indicating which of the following fields are set
3729 study_data opaque data from pcre_study()
3730 match_limit a way of specifying a limit on match() calls for a specific
3731 call to pcre_exec()
3732 callout_data data for callouts (see 49 below)
3734 The flag bits are also defined in pcre.h, and are
3740 The pcre_study() function now returns one of these new pcre_extra blocks, with
3741 the actual study data pointed to by the study_data field, and the
3742 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3743 before. That is, this change is entirely upwards-compatible and requires no
3744 change to existing code.
3746 If you want to pass in additional data to pcre_exec(), you can either place it
3747 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3748 block.
3750 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3751 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3752 times with different match limits, until it finds the minimum value needed for
3753 pcre_exec() to complete. The value is then output. This can be instructive; for
3754 most simple matches the number is quite small, but for pathological cases it
3755 gets very large very quickly.
3757 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3758 returns the size of the data block pointed to by the study_data field in a
3759 pcre_extra block, that is, the value that was passed as the argument to
3760 pcre_malloc() when PCRE was getting memory in which to place the information
3761 created by pcre_study(). The fourth argument should point to a size_t variable.
3762 pcretest has been extended so that this information is shown after a successful
3763 pcre_study() call when information about the compiled regex is being displayed.
3765 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3766 because what follows is always an absolute path. (Later: it turns out that this
3767 is more than cosmetic for MinGW, because it doesn't like empty path
3768 components.)
3770 49. Some changes have been made to the callout feature (see 28 above):
3772 (i) A callout function now has three choices for what it returns:
3774 0 => success, carry on matching
3775 > 0 => failure at this point, but backtrack if possible
3776 < 0 => serious error, return this value from pcre_exec()
3778 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3779 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3780 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3781 use by callout functions. It will never be used by PCRE itself.
3783 (ii) The pcre_extra structure (see 45 above) has a void * field called
3784 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3785 pcre_callout_block structure has a field of the same name. The contents of
3786 the field passed in the pcre_extra structure are passed to the callout
3787 function in the corresponding field in the callout block. This makes it
3788 easier to use the same callout-containing regex from multiple threads. For
3789 testing, the pcretest program has a new data escape
3791 \C*n pass the number n (may be negative) as callout_data
3793 If the callout function in pcretest receives a non-zero value as
3794 callout_data, it returns that value.
3796 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3797 there were some redundant $(CFLAGS) in commands that are now specified as
3798 $(LINK), which already includes $(CFLAGS).
3800 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3801 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3802 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3803 one-byte characters throughout. Note that case-insensitive matching applies
3804 only to characters whose values are less than 256. PCRE doesn't support the
3805 notion of cases for higher-valued characters.
3807 (i) A character class whose characters are all within 0-255 is handled as
3808 a bit map, and the map is inverted for negative classes. Previously, a
3809 character > 255 always failed to match such a class; however it should
3810 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3812 (ii) A negated character class with a single character < 255 is coded as
3813 "not this character" (OP_NOT). This wasn't working properly when the test
3814 character was multibyte, either singly or repeated.
3816 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3817 mode, for example: \x{100}{2,3}.
3819 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3820 singly or repeated) now correctly test multibyte characters. However,
3821 PCRE doesn't recognize any characters with values greater than 255 as
3822 digits, spaces, or word characters. Such characters always match \D, \S,
3823 and \W, and never match \d, \s, or \w.
3825 (v) Classes may now contain characters and character ranges with values
3826 greater than 255. For example: [ab\x{100}-\x{400}].
3828 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3829 PCRE in UTF-8 mode.
3831 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3832 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3833 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3834 value.)
3836 53. The single man page has become too large. I have therefore split it up into
3837 a number of separate man pages. These also give rise to individual HTML pages;
3838 these are now put in a separate directory, and there is an index.html page that
3839 lists them all. Some hyperlinking between the pages has been installed.
3841 54. Added convenience functions for handling named capturing parentheses.
3843 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3844 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3845 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3846 are faulted.
3848 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3849 calling configure. These values are used when compiling the dftables.c program
3850 which is run to generate the source of the default character tables. They
3851 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3852 you will need to set these values.
3854 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3857 Version 3.9 02-Jan-02
3858 ---------------------
3860 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3862 2. If --disable-static was given, the building process failed when trying to
3863 build pcretest and pcregrep. (For some reason it was using libtool to compile
3864 them, which is not right, as they aren't part of the library.)
3867 Version 3.8 18-Dec-01
3868 ---------------------
3870 1. The experimental UTF-8 code was completely screwed up. It was packing the
3871 bytes in the wrong order. How dumb can you get?
3874 Version 3.7 29-Oct-01
3875 ---------------------
3877 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3878 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3879 this didn't happen under Solaris 8, where I normally test things.
3881 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3882 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3883 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3884 this fix an hour or so after the initial 3.7 release.)
3887 Version 3.6 23-Oct-01
3888 ---------------------
3890 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3891 offsets passed as NULL with zero offset count.
3893 2. The config.guess and config.sub files had not been updated when I moved to
3894 the latest autoconf.
3897 Version 3.5 15-Aug-01
3898 ---------------------
3900 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3901 had been forgotten.
3903 2. By using declared but undefined structures, we can avoid using "void"
3904 definitions in pcre.h while keeping the internal definitions of the structures
3905 private.
3907 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3908 user point of view, this means that both static and shared libraries are built
3909 by default, but this can be individually controlled. More of the work of
3910 handling this static/shared cases is now inside libtool instead of PCRE's make
3911 file.
3913 4. The pcretest utility is now installed along with pcregrep because it is
3914 useful for users (to test regexs) and by doing this, it automatically gets
3915 relinked by libtool. The documentation has been turned into a man page, so
3916 there are now .1, .txt, and .html versions in /doc.
3918 5. Upgrades to pcregrep:
3919 (i) Added long-form option names like gnu grep.
3920 (ii) Added --help to list all options with an explanatory phrase.
3921 (iii) Added -r, --recursive to recurse into sub-directories.
3922 (iv) Added -f, --file to read patterns from a file.
3924 6. pcre_exec() was referring to its "code" argument before testing that
3925 argument for NULL (and giving an error if it was NULL).
3927 7. Upgraded Makefile.in to allow for compiling in a different directory from
3928 the source directory.
3930 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3931 options bits, the pointer it was passed was to an int instead of to an unsigned
3932 long int. This mattered only on 64-bit systems.
3934 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3935 generated) instead of pcre.in, which it its source. Also made the same change
3936 in several of the .c files.
3938 10. A new release of gcc defines printf() as a macro, which broke pcretest
3939 because it had an ifdef in the middle of a string argument for printf(). Fixed
3940 by using separate calls to printf().
3942 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3943 script, to force use of CR or LF instead of \n in the source. On non-Unix
3944 systems, the value can be set in config.h.
3946 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3947 absolute limit. Changed the text of the error message to make this clear, and
3948 likewise updated the man page.
3950 13. The limit of 99 on the number of capturing subpatterns has been removed.
3951 The new limit is 65535, which I hope will not be a "real" limit.
3954 Version 3.4 22-Aug-00
3955 ---------------------
3957 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3959 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3962 Version 3.3 01-Aug-00
3963 ---------------------
3965 1. If an octal character was given, but the value was greater than \377, it
3966 was not getting masked to the least significant bits, as documented. This could
3967 lead to crashes in some systems.
3969 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3970 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3972 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3973 These just pass their arguments on to (pcre_free)(), but they are provided
3974 because some uses of PCRE bind it to non-C systems that can call its functions,
3975 but cannot call free() or pcre_free() directly.
3977 4. Add "make test" as a synonym for "make check". Corrected some comments in
3978 the Makefile.
3980 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3981 Makefile.
3983 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3984 command called pgrep for grepping around the active processes.
3986 7. Added the beginnings of support for UTF-8 character strings.
3988 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3989 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3990 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3991 out for the ar command.)
3994 Version 3.2 12-May-00
3995 ---------------------
3997 This is purely a bug fixing release.
3999 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4000 of ZA. This was just one example of several cases that could provoke this bug,
4001 which was introduced by change 9 of version 2.00. The code for breaking
4002 infinite loops after an iteration that matches an empty string was't working
4003 correctly.
4005 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4006 when matched against abbab (for example). After matching an empty string, it
4007 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4008 caused it to match further down the string than it should.
4010 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4011 was there because it doesn't seem to be needed, and it causes trouble on some
4012 systems, as it is not a Standard C header. It has been removed.
4014 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4015 were reported on the Macintosh. The changes were from
4017 while ((c = *(++ptr)) != 0 && c != '\n');
4018 to
4019 while ((c = *(++ptr)) != 0 && c != '\n') ;
4021 Totally extraordinary, but if that's what it takes...
4023 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4024 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4025 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4026 assumes the way PCRE uses memmove() (always moving upwards).
4028 6. PCRE is being used in one environment where strchr() is not available. There
4029 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4030 faster code anyway.
4033 Version 3.1 09-Feb-00
4034 ---------------------
4036 The only change in this release is the fixing of some bugs in Makefile.in for
4037 the "install" target:
4039 (1) It was failing to install pcreposix.h.
4041 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4044 Version 3.0 01-Feb-00
4045 ---------------------
4047 1. Add support for the /+ modifier to perltest (to output $` like it does in
4048 pcretest).
4050 2. Add support for the /g modifier to perltest.
4052 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4053 matches null strings.
4055 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4056 pattern. Perl treats empty patterns specially - it reuses the most recent
4057 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4058 effect.
4060 5. The POSIX interface was broken in that it was just handing over the POSIX
4061 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4062 required a bigger vector, with some working space on the end. This means that
4063 the POSIX wrapper now has to get and free some memory, and copy the results.
4065 6. Added some simple autoconf support, placing the test data and the
4066 documentation in separate directories, re-organizing some of the
4067 information files, and making it build pcre-config (a GNU standard). Also added
4068 libtool support for building PCRE as a shared library, which is now the
4069 default.
4071 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4072 09 are not valid octal constants. Single digits will be used for minor values
4073 less than 10.
4075 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4076 existing programs that set these in the POSIX interface can use PCRE without
4077 modification.
4079 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4080 return all that pcre_info() returns, plus additional data. The pcre_info()
4081 function is retained for compatibility, but is considered to be obsolete.
4083 10. Added experimental recursion feature (?R) to handle one common case that
4084 Perl 5.6 will be able to do with (?p{...}).
4086 11. Added support for POSIX character classes like [:alpha:], which Perl is
4087 adopting.
4090 Version 2.08 31-Aug-99
4091 ----------------------
4093 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4094 trying to match at the startoffset position, but instead was moving forward to
4095 the next newline as if a previous match had failed.
4097 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4098 and could get into a loop if a null string was matched other than at the start
4099 of the subject.
4101 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4102 be distinguished at compile time, and for completeness also added PCRE_DATE.
4104 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4105 in GnuWin32 environments.
4108 Version 2.07 29-Jul-99
4109 ----------------------
4111 1. The documentation is now supplied in plain text form and HTML as well as in
4112 the form of man page sources.
4114 2. C++ compilers don't like assigning (void *) values to other pointer types.
4115 In particular this affects malloc(). Although there is no problem in Standard
4116 C, I've put in casts to keep C++ compilers happy.
4118 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4119 should be (const char *).
4121 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4122 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4123 However, I haven't made this a standard facility. The documentation doesn't
4124 mention it, and the Makefile doesn't support it.
4126 5. The Makefile now contains an "install" target, with editable destinations at
4127 the top of the file. The pcretest program is not installed.
4129 6. pgrep -V now gives the PCRE version number and date.
4131 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4132 causing the entire string to be ignored, instead of just the last character.
4134 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4135 non-matching string, it can take a very, very long time, even for strings of
4136 quite modest length, because of the nested recursion. PCRE now does better in
4137 some of these cases. It does this by remembering the last required literal
4138 character in the pattern, and pre-searching the subject to ensure it is present
4139 before running the real match. In other words, it applies a heuristic to detect
4140 some types of certain failure quickly, and in the above example, if presented
4141 with a string that has no trailing " it gives "no match" very quickly.
4143 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4144 other alternatives are tried instead.
4147 Version 2.06 09-Jun-99
4148 ----------------------
4150 1. Change pcretest's output for amount of store used to show just the code
4151 space, because the remainder (the data block) varies in size between 32-bit and
4152 64-bit systems.
4154 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4155 start matching at. This allows lookbehinds to work when searching for multiple
4156 occurrences in a string.
4158 3. Added additional options to pcretest for testing multiple occurrences:
4160 /+ outputs the rest of the string that follows a match
4161 /g loops for multiple occurrences, using the new startoffset argument
4162 /G loops for multiple occurrences by passing an incremented pointer
4164 4. PCRE wasn't doing the "first character" optimization for patterns starting
4165 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4166 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4167 the letter 'x'. On long subject strings, this gives a significant speed-up.
4170 Version 2.05 21-Apr-99
4171 ----------------------
4173 1. Changed the type of magic_number from int to long int so that it works
4174 properly on 16-bit systems.
4176 2. Fixed a bug which caused patterns starting with .* not to work correctly
4177 when the subject string contained newline characters. PCRE was assuming
4178 anchoring for such patterns in all cases, which is not correct because .* will
4179 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4180 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4181 must be retried after every newline in the subject.
4184 Version 2.04 18-Feb-99
4185 ----------------------
4187 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4188 computation of the store needed to hold the pattern was incorrect (too large).
4189 If such patterns were nested a few deep, this could multiply and become a real
4190 problem.
4192 2. Added /M option to pcretest to show the memory requirement of a specific
4193 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4195 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4196 compiled in such a way that the backtracking after subsequent failure was
4197 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4198 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4201 Version 2.03 02-Feb-99
4202 ----------------------
4204 1. Fixed typo and small mistake in man page.
4206 2. Added 4th condition (GPL supersedes if conflict) and created separate
4207 LICENCE file containing the conditions.
4209 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4210 Perl, that is the internal \ allows the delimiter to be included in the
4211 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4212 the final delimiter, add \ to the end of the pattern (to test the error).
4214 4. Added the convenience functions for extracting substrings after a successful
4215 match. Updated pcretest to make it able to test these functions.
4218 Version 2.02 14-Jan-99
4219 ----------------------
4221 1. Initialized the working variables associated with each extraction so that
4222 their saving and restoring doesn't refer to uninitialized store.
4224 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4225 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4226 fix the problem.
4228 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4229 calls, and wasn't printing the correct value for compiling calls. Increased the
4230 default value of LOOPREPEAT, and the number of significant figures in the
4231 times.
4233 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4235 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4236 a building problem on Windows NT with a FAT file system.
4239 Version 2.01 21-Oct-98
4240 ----------------------
4242 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4243 to character tables built by pcre_maketables() in the current locale. If NULL
4244 is passed, the default tables are used.
4247 Version 2.00 24-Sep-98
4248 ----------------------
4250 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4251 it any more.
4253 2. Allow quantification of (?>) groups, and make it work correctly.
4255 3. The first character computation wasn't working for (?>) groups.
4257 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4258 end of the subject) and add 5.005's \z, which really does match only at the
4259 very end of the subject.
4261 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4263 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4264 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4265 localized options. All options to pcre_study() were also removed.
4267 7. Add other new features from 5.005:
4269 $(?<= positive lookbehind
4270 $(?<! negative lookbehind
4271 (?imsx-imsx) added the unsetting capability
4272 such a setting is global if at outer level; local otherwise
4273 (?imsx-imsx:) non-capturing groups with option setting
4274 (?(cond)re|re) conditional pattern matching
4276 A backreference to itself in a repeated group matches the previous
4277 captured string.
4279 8. General tidying up of studying (both automatic and via "study")
4280 consequential on the addition of new assertions.
4282 9. As in 5.005, unlimited repeated groups that could match an empty substring
4283 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4284 runtime if any iteration does actually match an empty substring.
4286 10. Include the RunTest script in the distribution.
4288 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4289 discrepancies, some of which were old and were also with respect to 5.004. They
4290 have now been fixed.
4293 Version 1.09 28-Apr-98
4294 ----------------------
4296 1. A negated single character class followed by a quantifier with a minimum
4297 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4298 program crashes, or just wrong answers. This did not apply to negated classes
4299 containing more than one character, or to minima other than one.
4302 Version 1.08 27-Mar-98
4303 ----------------------
4305 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4307 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4308 latter must appear before anything that relies on it in the pattern.
4311 Version 1.07 16-Feb-98
4312 ----------------------
4314 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4315 repeat of a potentially empty string).
4318 Version 1.06 23-Jan-98
4319 ----------------------
4321 1. Added Markus Oberhumer's little patches for C++.
4323 2. Literal strings longer than 255 characters were broken.
4326 Version 1.05 23-Dec-97
4327 ----------------------
4329 1. Negated character classes containing more than one character were failing if
4330 PCRE_CASELESS was set at run time.
4333 Version 1.04 19-Dec-97
4334 ----------------------
4336 1. Corrected the man page, where some "const" qualifiers had been omitted.
4338 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4339 input syntax.
4341 3. Fixed memory leak which occurred when a regex with back references was
4342 matched with an offsets vector that wasn't big enough. The temporary memory
4343 that is used in this case wasn't being freed if the match failed.
4345 4. Tidied pcretest to ensure it frees memory that it gets.
4347 5. Temporary memory was being obtained in the case where the passed offsets
4348 vector was exactly big enough.
4350 6. Corrected definition of offsetof() from change 5 below.
4352 7. I had screwed up change 6 below and broken the rules for the use of
4353 setjmp(). Now fixed.
4356 Version 1.03 18-Dec-97
4357 ----------------------
4359 1. A erroneous regex with a missing opening parenthesis was correctly
4360 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4361 on some systems.
4363 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4364 it was reported that one broken compiler failed on the former because "code" is
4365 also an independent variable.
4367 3. The erroneous regex a[]b caused an array overrun reference.
4369 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4370 fail on data ending with that character. (It was going on too far, and checking
4371 the next character, typically a binary zero.) This was specific to the
4372 optimized code for single-character negative classes.
4374 5. Added a contributed patch from the TIN world which does the following:
4376 + Add an undef for memmove, in case the the system defines a macro for it.
4378 + Add a definition of offsetof(), in case there isn't one. (I don't know
4379 the reason behind this - offsetof() is part of the ANSI standard - but
4380 it does no harm).
4382 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4383 most of the places where whitespace preceded '#'. I have given up and
4384 allowed the remaining 2 cases to be at the margin.
4386 + Rename some variables in pcre to eliminate shadowing. This seems very
4387 pedantic, but does no harm, of course.
4389 6. Moved the call to setjmp() into its own function, to get rid of warnings
4390 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4392 7. Constructs such as \d{8,} were compiling into the equivalent of
4393 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4394 outcome, but in this particular case used more store than had been allocated,
4395 which caused the bug to be discovered because it threw up an internal error.
4397 8. The debugging code in both pcre and pcretest for outputting the compiled
4398 form of a regex was going wrong in the case of back references followed by
4399 curly-bracketed repeats.
4402 Version 1.02 12-Dec-97
4403 ----------------------
4405 1. Typos in pcre.3 and comments in the source fixed.
4407 2. Applied a contributed patch to get rid of places where it used to remove
4408 'const' from variables, and fixed some signed/unsigned and uninitialized
4409 variable warnings.
4411 3. Added the "runtest" target to Makefile.
4413 4. Set default compiler flag to -O2 rather than just -O.
4416 Version 1.01 19-Nov-97
4417 ----------------------
4419 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4420 like /([ab]*)*/, that is, for classes with more than one character in them.
4422 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4423 as /((?>a*))*/ (a PCRE_EXTRA facility).
4426 Version 1.00 18-Nov-97
4427 ----------------------
4429 1. Added compile-time macros to support systems such as SunOS4 which don't have
4430 memmove() or strerror() but have other things that can be used instead.
4432 2. Arranged that "make clean" removes the executables.
4435 Version 0.99 27-Oct-97
4436 ----------------------
4438 1. Fixed bug in code for optimizing classes with only one character. It was
4439 initializing a 32-byte map regardless, which could cause it to run off the end
4440 of the memory it had got.
4442 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4445 Version 0.98 22-Oct-97
4446 ----------------------
4448 1. Fixed bug in code for handling temporary memory usage when there are more
4449 back references than supplied space in the ovector. This could cause segfaults.
4452 Version 0.97 21-Oct-97
4453 ----------------------
4455 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4457 2. Optimized negated single characters not to use a bit map.
4459 3. Brought error texts together as macro definitions; clarified some of them;
4460 fixed one that was wrong - it said "range out of order" when it meant "invalid
4461 escape sequence".
4463 4. Changed some char * arguments to const char *.
4465 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4467 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4468 pcretest.
4471 Version 0.96 16-Oct-97
4472 ----------------------
4474 1. Added a simple "pgrep" utility to the distribution.
4476 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4477 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4478 where "ddd" means "one or more decimal digits".
4480 3. Fixed serious bug. If a pattern had a back reference, but the call to
4481 pcre_exec() didn't supply a large enough ovector to record the related
4482 identifying subpattern, the match always failed. PCRE now remembers the number
4483 of the largest back reference, and gets some temporary memory in which to save
4484 the offsets during matching if necessary, in order to ensure that
4485 backreferences always work.
4487 4. Increased the compatibility with Perl in a number of ways:
4489 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4490 to request this handling. The option can be set at compile or exec time.
4492 (b) $ matches before a terminating newline by default; an option
4493 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4494 mode). The option can be set at compile or exec time.
4496 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4497 the same as Perl's. If the decimal number it represents is less than 10
4498 or there aren't that many previous left capturing parentheses, an octal
4499 escape is read. Inside a character class, it's always an octal escape,
4500 even if it is a single digit.
4502 (d) An escaped but undefined alphabetic character is taken as a literal,
4503 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4504 escapes.
4506 (e) {0} is now permitted. (The previous item is removed from the compiled
4507 pattern).
4509 5. Changed all the names of code files so that the basic parts are no longer
4510 than 10 characters, and abolished the teeny "globals.c" file.
4512 6. Changed the handling of character classes; they are now done with a 32-byte
4513 bit map always.
4515 7. Added the -d and /D options to pcretest to make it possible to look at the
4516 internals of compilation without having to recompile pcre.
4519 Version 0.95 23-Sep-97
4520 ----------------------
4522 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4523 \x20 at the start of a run of normal characters. These were being treated as
4524 real characters, instead of the source characters being re-checked.
4527 Version 0.94 18-Sep-97
4528 ----------------------
4530 1. The functions are now thread-safe, with the caveat that the global variables
4531 containing pointers to malloc() and free() or alternative functions are the
4532 same for all threads.
4534 2. Get pcre_study() to generate a bitmap of initial characters for non-
4535 anchored patterns when this is possible, and use it if passed to pcre_exec().
4538 Version 0.93 15-Sep-97
4539 ----------------------
4541 1. /(b)|(:+)/ was computing an incorrect first character.
4543 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4544 but not actually doing anything yet.
4546 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4547 as Perl does (e.g. [-az] or [az-]).
4549 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4550 all possible positions.
4552 5. Split up into different modules to avoid including unneeded functions in a
4553 compiled binary. However, compile and exec are still in one module. The "study"
4554 function is split off.
4556 6. The character tables are now in a separate module whose source is generated
4557 by an auxiliary program - but can then be edited by hand if required. There are
4558 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4559 toupper() in the code.
4561 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4562 make them global. Abolish the function for setting them, as the caller can now
4563 set them directly.
4566 Version 0.92 11-Sep-97
4567 ----------------------
4569 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4570 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4572 2. Caseless matching was not working in character classes if the characters in
4573 the pattern were in upper case.
4575 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4577 4. Make PCRE_ANCHORED public and accept as a compile option.
4579 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4580 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4581 pass them.
4583 6. Give an error if bad option bits passed at compile or run time.
4585 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4586 pcretest to cause it to pass that flag.
4588 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4589 options, and the first character, if set.
4591 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4594 Version 0.91 10-Sep-97
4595 ----------------------
4597 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4598 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4600 2. PCRE was looping on encountering an indefinitely repeated back reference to
4601 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4602 Perl does - treats the match as successful.
4604 ****


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