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Revision 195 - (show annotations) (download)
Mon Jul 30 13:23:28 2007 UTC (7 years, 1 month ago) by ph10
File size: 131434 byte(s)
Add words about EBCDIC to doc and ./configure --help (somebody thought it might
be a useful option and tried it on an ASCII system). Fixed one missing table
entry for EBCDIC. 

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

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