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Revision 197 - (show annotations) (download)
Tue Jul 31 10:50:18 2007 UTC (7 years ago) by ph10
File size: 132375 byte(s)
Abolish the NULLWSLIMIT error at the expense of using more stack when an 
unlimited repeat could match an empty string. Also, doc tidies for a test 
release.

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

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