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Revision 200 - (show annotations) (download)
Wed Aug 1 09:10:40 2007 UTC (7 years, 3 months ago) by ph10
File size: 132652 byte(s)
Correct errors in previous patch; tidy for 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 8. Applied Daniel's patches to solve problems with the import/export magic
52 syntax that is required for Windows, and which was going wrong for the
53 pcreposix and pcrecpp parts of the library. These were overlooked when this
54 problem was solved for the main library.
55
56
57 Version 7.2 19-Jun-07
58 ---------------------
59
60 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
61 which is apparently normally available under Windows.
62
63 2. Re-jig the pcregrep tests with different newline settings in an attempt
64 to make them independent of the local environment's newline setting.
65
66 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
67
68 4. Some of the "internals" tests were previously cut out when the link size
69 was not 2, because the output contained actual offsets. The recent new
70 "Z" feature of pcretest means that these can be cut out, making the tests
71 usable with all link sizes.
72
73 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
74 stack recursion. This gives a massive performance boost under BSD, but just
75 a small improvement under Linux. However, it saves one field in the frame
76 in all cases.
77
78 6. Added more features from the forthcoming Perl 5.10:
79
80 (a) (?-n) (where n is a string of digits) is a relative subroutine or
81 recursion call. It refers to the nth most recently opened parentheses.
82
83 (b) (?+n) is also a relative subroutine call; it refers to the nth next
84 to be opened parentheses.
85
86 (c) Conditions that refer to capturing parentheses can be specified
87 relatively, for example, (?(-2)... or (?(+3)...
88
89 (d) \K resets the start of the current match so that everything before
90 is not part of it.
91
92 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
93
94 (f) \g{name} is another synonym - part of Perl 5.10's unification of
95 reference syntax.
96
97 (g) (?| introduces a group in which the numbering of parentheses in each
98 alternative starts with the same number.
99
100 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
101
102 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
103 PCRE_INFO_JCHANGED.
104
105 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
106 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
107 for detecting groups that can match an empty string.
108
109 9. A pattern with a very large number of alternatives (more than several
110 hundred) was running out of internal workspace during the pre-compile
111 phase, where pcre_compile() figures out how much memory will be needed. A
112 bit of new cunning has reduced the workspace needed for groups with
113 alternatives. The 1000-alternative test pattern now uses 12 bytes of
114 workspace instead of running out of the 4096 that are available.
115
116 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
117
118 11. Applied patch from Google to remove an optimization that didn't quite work.
119 The report of the bug said:
120
121 pcrecpp::RE("a*").FullMatch("aaa") matches, while
122 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
123 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
124
125 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
126 it matched the wrong number of bytes.
127
128
129 Version 7.1 24-Apr-07
130 ---------------------
131
132 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
133 that is more "standard", making use of automake and other Autotools. There
134 is some re-arrangement of the files and adjustment of comments consequent
135 on this.
136
137 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
138 for recursive directory scanning broke on some systems because the files
139 are not scanned in any specific order and on different systems the order
140 was different. A call to "sort" has been inserted into RunGrepTest for the
141 approprate test as a short-term fix. In the longer term there may be an
142 alternative.
143
144 3. I had an email from Eric Raymond about problems translating some of PCRE's
145 man pages to HTML (despite the fact that I distribute HTML pages, some
146 people do their own conversions for various reasons). The problems
147 concerned the use of low-level troff macros .br and .in. I have therefore
148 removed all such uses from the man pages (some were redundant, some could
149 be replaced by .nf/.fi pairs). The 132html script that I use to generate
150 HTML has been updated to handle .nf/.fi and to complain if it encounters
151 .br or .in.
152
153 4. Updated comments in configure.ac that get placed in config.h.in and also
154 arranged for config.h to be included in the distribution, with the name
155 config.h.generic, for the benefit of those who have to compile without
156 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
157
158 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
159 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
160 makevp.bat for the current PCRE, using the additional files
161 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
162
163 6. A Windows user reported a minor discrepancy with test 2, which turned out
164 to be caused by a trailing space on an input line that had got lost in his
165 copy. The trailing space was an accident, so I've just removed it.
166
167 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
168 that is needed.
169
170 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
171 as "const" (a) because they are and (b) because it helps the PHP
172 maintainers who have recently made a script to detect big data structures
173 in the php code that should be moved to the .rodata section. I remembered
174 to update Builducptable as well, so it won't revert if ucptable.h is ever
175 re-created.
176
177 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
178 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
179 order to be able to cut out the UTF-8 tables in the latter when UTF-8
180 support is not required. This saves 1.5-2K of code, which is important in
181 some applications.
182
183 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
184 so as not to refer to the tables, even though these functions will never be
185 called when UTF-8 support is disabled. Otherwise there are problems with a
186 shared library.
187
188 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
189
190 (a) It was defining its arguments as char * instead of void *.
191
192 (b) It was assuming that all moves were upwards in memory; this was true
193 a long time ago when I wrote it, but is no longer the case.
194
195 The emulated memove() is provided for those environments that have neither
196 memmove() nor bcopy(). I didn't think anyone used it these days, but that
197 is clearly not the case, as these two bugs were recently reported.
198
199 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
200 and Detrail to create the HTML documentation, the .txt form of the man
201 pages, and it removes trailing spaces from listed files. It also creates
202 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
203 case, it wraps all the #defines with #ifndefs. This script should be run
204 before "make dist".
205
206 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
207 with Unicode property support.
208
209 (a) For a maximizing quantifier, if the two different cases of the
210 character were of different lengths in their UTF-8 codings (there are
211 some cases like this - I found 11), and the matching function had to
212 back up over a mixture of the two cases, it incorrectly assumed they
213 were both the same length.
214
215 (b) When PCRE was configured to use the heap rather than the stack for
216 recursion during matching, it was not correctly preserving the data for
217 the other case of a UTF-8 character when checking ahead for a match
218 while processing a minimizing repeat. If the check also involved
219 matching a wide character, but failed, corruption could cause an
220 erroneous result when trying to check for a repeat of the original
221 character.
222
223 13. Some tidying changes to the testing mechanism:
224
225 (a) The RunTest script now detects the internal link size and whether there
226 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
227 values substituted by "configure". (The RunGrepTest script already did
228 this for UTF-8.) The configure.ac script no longer substitutes the
229 relevant variables.
230
231 (b) The debugging options /B and /D in pcretest show the compiled bytecode
232 with length and offset values. This means that the output is different
233 for different internal link sizes. Test 2 is skipped for link sizes
234 other than 2 because of this, bypassing the problem. Unfortunately,
235 there was also a test in test 3 (the locale tests) that used /B and
236 failed for link sizes other than 2. Rather than cut the whole test out,
237 I have added a new /Z option to pcretest that replaces the length and
238 offset values with spaces. This is now used to make test 3 independent
239 of link size. (Test 2 will be tidied up later.)
240
241 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
242 segmentation fault instead of returning the appropriate error message.
243
244 15. In multiline mode when the newline sequence was set to "any", the pattern
245 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
246 This doesn't seem right; it now treats the CRLF combination as the line
247 ending, and so does not match in that case. It's only a pattern such as ^$
248 that would hit this one: something like ^ABC$ would have failed after \r
249 and then tried again after \r\n.
250
251 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
252 in an attempt to make files that differ only in their line terminators
253 compare equal. This works on Linux.
254
255 17. Under certain error circumstances pcregrep might try to free random memory
256 as it exited. This is now fixed, thanks to valgrind.
257
258 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
259 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
260 was because its rules for how to advance for /g after matching an empty
261 string at the end of a line did not allow for this case. They now check for
262 it specially.
263
264 20. pcretest is supposed to handle patterns and data of any length, by
265 extending its buffers when necessary. It was getting this wrong when the
266 buffer for a data line had to be extended.
267
268 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
269 CRLF as a newline sequence.
270
271 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
272 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
273 I have nevertheless tidied it up.
274
275 23. Added some casts to kill warnings from HP-UX ia64 compiler.
276
277 24. Added a man page for pcre-config.
278
279
280 Version 7.0 19-Dec-06
281 ---------------------
282
283 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
284 moving to gcc 4.1.1.
285
286 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
287 sys/time.h, which is documented as needed for this function. It doesn't
288 seem to matter on Linux, but it showed up on some releases of OS X.
289
290 3. It seems that there are systems where bytes whose values are greater than
291 127 match isprint() in the "C" locale. The "C" locale should be the
292 default when a C program starts up. In most systems, only ASCII printing
293 characters match isprint(). This difference caused the output from pcretest
294 to vary, making some of the tests fail. I have changed pcretest so that:
295
296 (a) When it is outputting text in the compiled version of a pattern, bytes
297 other than 32-126 are always shown as hex escapes.
298
299 (b) When it is outputting text that is a matched part of a subject string,
300 it does the same, unless a different locale has been set for the match
301 (using the /L modifier). In this case, it uses isprint() to decide.
302
303 4. Fixed a major bug that caused incorrect computation of the amount of memory
304 required for a compiled pattern when options that changed within the
305 pattern affected the logic of the preliminary scan that determines the
306 length. The relevant options are -x, and -i in UTF-8 mode. The result was
307 that the computed length was too small. The symptoms of this bug were
308 either the PCRE error "internal error: code overflow" from pcre_compile(),
309 or a glibc crash with a message such as "pcretest: free(): invalid next
310 size (fast)". Examples of patterns that provoked this bug (shown in
311 pcretest format) are:
312
313 /(?-x: )/x
314 /(?x)(?-x: \s*#\s*)/
315 /((?i)[\x{c0}])/8
316 /(?i:[\x{c0}])/8
317
318 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
319 is now done differently.
320
321 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
322 wrapper classes; (b) implement a new function in the C++ scanner that is
323 more efficient than the old way of doing things because it avoids levels of
324 recursion in the regex matching; (c) add a paragraph to the documentation
325 for the FullMatch() function.
326
327 6. The escape sequence \n was being treated as whatever was defined as
328 "newline". Not only was this contrary to the documentation, which states
329 that \n is character 10 (hex 0A), but it also went horribly wrong when
330 "newline" was defined as CRLF. This has been fixed.
331
332 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
333 was being set to -1 for the "end of line" case (supposedly a value that no
334 character can have). Though this value is never used (the check for end of
335 line is "zero bytes in current character"), it caused compiler complaints.
336 I've changed it to 0xffffffff.
337
338 8. In pcre_version.c, the version string was being built by a sequence of
339 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
340 string (as it is for production releases) called a macro with an empty
341 argument. The C standard says the result of this is undefined. The gcc
342 compiler treats it as an empty string (which was what was wanted) but it is
343 reported that Visual C gives an error. The source has been hacked around to
344 avoid this problem.
345
346 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
347 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
348 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
349 of them did).
350
351 10. Originally, pcretest opened its input and output without "b"; then I was
352 told that "b" was needed in some environments, so it was added for release
353 5.0 to both the input and output. (It makes no difference on Unix-like
354 systems.) Later I was told that it is wrong for the input on Windows. I've
355 now abstracted the modes into two macros, to make it easier to fiddle with
356 them, and removed "b" from the input mode under Windows.
357
358 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
359
360 12. Added -help and --help to pcretest as an official way of being reminded
361 of the options.
362
363 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
364 and pcrecpp.cc because they annoy compilers at high warning levels.
365
366 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
367
368 15. Fixed an occurrence of == in configure.ac that should have been = (shell
369 scripts are not C programs :-) and which was not noticed because it works
370 on Linux.
371
372 16. pcretest is supposed to handle any length of pattern and data line (as one
373 line or as a continued sequence of lines) by extending its input buffer if
374 necessary. This feature was broken for very long pattern lines, leading to
375 a string of junk being passed to pcre_compile() if the pattern was longer
376 than about 50K.
377
378 17. I have done a major re-factoring of the way pcre_compile() computes the
379 amount of memory needed for a compiled pattern. Previously, there was code
380 that made a preliminary scan of the pattern in order to do this. That was
381 OK when PCRE was new, but as the facilities have expanded, it has become
382 harder and harder to keep it in step with the real compile phase, and there
383 have been a number of bugs (see for example, 4 above). I have now found a
384 cunning way of running the real compile function in a "fake" mode that
385 enables it to compute how much memory it would need, while actually only
386 ever using a few hundred bytes of working memory and without too many
387 tests of the mode. This should make future maintenance and development
388 easier. A side effect of this work is that the limit of 200 on the nesting
389 depth of parentheses has been removed (though this was never a serious
390 limitation, I suspect). However, there is a downside: pcre_compile() now
391 runs more slowly than before (30% or more, depending on the pattern). I
392 hope this isn't a big issue. There is no effect on runtime performance.
393
394 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
395 newline (only possible for the last line of a file) and it was a
396 pattern that set a locale (followed by /Lsomething), pcretest crashed.
397
398 19. Added additional timing features to pcretest. (1) The -tm option now times
399 matching only, not compiling. (2) Both -t and -tm can be followed, as a
400 separate command line item, by a number that specifies the number of
401 repeats to use when timing. The default is 50000; this gives better
402 precision, but takes uncomfortably long for very large patterns.
403
404 20. Extended pcre_study() to be more clever in cases where a branch of a
405 subpattern has no definite first character. For example, (a*|b*)[cd] would
406 previously give no result from pcre_study(). Now it recognizes that the
407 first character must be a, b, c, or d.
408
409 21. There was an incorrect error "recursive call could loop indefinitely" if
410 a subpattern (or the entire pattern) that was being tested for matching an
411 empty string contained only one non-empty item after a nested subpattern.
412 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
413 incorrectly, because the \d was being skipped in the check.
414
415 22. The pcretest program now has a new pattern option /B and a command line
416 option -b, which is equivalent to adding /B to every pattern. This causes
417 it to show the compiled bytecode, without the additional information that
418 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
419 is the same as /B/I).
420
421 23. A new optimization is now able automatically to treat some sequences such
422 as a*b as a*+b. More specifically, if something simple (such as a character
423 or a simple class like \d) has an unlimited quantifier, and is followed by
424 something that cannot possibly match the quantified thing, the quantifier
425 is automatically "possessified".
426
427 24. A recursive reference to a subpattern whose number was greater than 39
428 went wrong under certain circumstances in UTF-8 mode. This bug could also
429 have affected the operation of pcre_study().
430
431 25. Realized that a little bit of performance could be had by replacing
432 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
433
434 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
435
436 27. Possessive quantifiers such as a++ were previously implemented by turning
437 them into atomic groups such as ($>a+). Now they have their own opcodes,
438 which improves performance. This includes the automatically created ones
439 from 23 above.
440
441 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
442 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
443 the first matched character to be a colon. This applied both to named and
444 numbered groups.
445
446 29. The ucpinternal.h header file was missing its idempotency #ifdef.
447
448 30. I was sent a "project" file called libpcre.a.dev which I understand makes
449 building PCRE on Windows easier, so I have included it in the distribution.
450
451 31. There is now a check in pcretest against a ridiculously large number being
452 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
453 loop, the loop is abandoned.
454
455 32. Forward references to subpatterns in conditions such as (?(2)...) where
456 subpattern 2 is defined later cause pcre_compile() to search forwards in
457 the pattern for the relevant set of parentheses. This search went wrong
458 when there were unescaped parentheses in a character class, parentheses
459 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
460
461 33. "Subroutine" calls and backreferences were previously restricted to
462 referencing subpatterns earlier in the regex. This restriction has now
463 been removed.
464
465 34. Added a number of extra features that are going to be in Perl 5.10. On the
466 whole, these are just syntactic alternatives for features that PCRE had
467 previously implemented using the Python syntax or my own invention. The
468 other formats are all retained for compatibility.
469
470 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
471 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
472 also .NET compatible.
473
474 (b) A recursion or subroutine call to a named group can now be defined as
475 (?&name) as well as (?P>name).
476
477 (c) A backreference to a named group can now be defined as \k<name> or
478 \k'name' as well as (?P=name). The new forms, as well as being in Perl
479 5.10, are also .NET compatible.
480
481 (d) A conditional reference to a named group can now use the syntax
482 (?(<name>) or (?('name') as well as (?(name).
483
484 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
485 groups (named and numbered) that are never evaluated inline, but can be
486 called as "subroutines" from elsewhere. In effect, the DEFINE condition
487 is always false. There may be only one alternative in such a group.
488
489 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
490 as the simple (?(R). The condition is true only if the most recent
491 recursion is that of the given number or name. It does not search out
492 through the entire recursion stack.
493
494 (g) The escape \gN or \g{N} has been added, where N is a positive or
495 negative number, specifying an absolute or relative reference.
496
497 35. Tidied to get rid of some further signed/unsigned compiler warnings and
498 some "unreachable code" warnings.
499
500 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
501 things, this adds five new scripts.
502
503 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
504 There were also incompatibilities regarding the handling of \Q..\E inside
505 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
506 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
507
508 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
509 matches an empty string, and forcibly breaks the loop. There were bugs in
510 this code in non-simple cases. For a pattern such as ^(a()*)* matched
511 against aaaa the result was just "a" rather than "aaaa", for example. Two
512 separate and independent bugs (that affected different cases) have been
513 fixed.
514
515 39. Refactored the code to abolish the use of different opcodes for small
516 capturing bracket numbers. This is a tidy that I avoided doing when I
517 removed the limit on the number of capturing brackets for 3.5 back in 2001.
518 The new approach is not only tidier, it makes it possible to reduce the
519 memory needed to fix the previous bug (38).
520
521 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
522 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
523 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
524 mode.
525
526 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
527 report.
528
529 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
530 copy construction and assignment in the C++ wrapper.
531
532 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
533 couple of bugs that could have given wrong results in the "--newline=crlf"
534 case.
535
536 44. Added a number of casts and did some reorganization of signed/unsigned int
537 variables following suggestions from Dair Grant. Also renamed the variable
538 "this" as "item" because it is a C++ keyword.
539
540 45. Arranged for dftables to add
541
542 #include "pcre_internal.h"
543
544 to pcre_chartables.c because without it, gcc 4.x may remove the array
545 definition from the final binary if PCRE is built into a static library and
546 dead code stripping is activated.
547
548 46. For an unanchored pattern, if a match attempt fails at the start of a
549 newline sequence, and the newline setting is CRLF or ANY, and the next two
550 characters are CRLF, advance by two characters instead of one.
551
552
553 Version 6.7 04-Jul-06
554 ---------------------
555
556 1. In order to handle tests when input lines are enormously long, pcretest has
557 been re-factored so that it automatically extends its buffers when
558 necessary. The code is crude, but this _is_ just a test program. The
559 default size has been increased from 32K to 50K.
560
561 2. The code in pcre_study() was using the value of the re argument before
562 testing it for NULL. (Of course, in any sensible call of the function, it
563 won't be NULL.)
564
565 3. The memmove() emulation function in pcre_internal.h, which is used on
566 systems that lack both memmove() and bcopy() - that is, hardly ever -
567 was missing a "static" storage class specifier.
568
569 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
570 containing an extended class (one that cannot be represented by a bitmap
571 because it contains high-valued characters or Unicode property items, e.g.
572 [\pZ]). Almost always one would set UTF-8 mode when processing such a
573 pattern, but PCRE should not loop if you do not (it no longer does).
574 [Detail: two cases were found: (a) a repeated subpattern containing an
575 extended class; (b) a recursive reference to a subpattern that followed a
576 previous extended class. It wasn't skipping over the extended class
577 correctly when UTF-8 mode was not set.]
578
579 5. A negated single-character class was not being recognized as fixed-length
580 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
581 compile error "lookbehind assertion is not fixed length".
582
583 6. The RunPerlTest auxiliary script was showing an unexpected difference
584 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
585 write a Perl script that can interpret lines of an input file either as
586 byte characters or as UTF-8, which is what "perltest" was being required to
587 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
588 can't do is switch easily at run time between having the "use utf8;" pragma
589 or not. In the end, I fudged it by using the RunPerlTest script to insert
590 "use utf8;" explicitly for the UTF-8 tests.
591
592 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
593 the end of the subject string, contrary to the documentation and to what
594 Perl does. This was true of both matching functions. Now it matches only at
595 the start of the subject and immediately after *internal* newlines.
596
597 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
598 a pointer to an int instead of a pointer to an unsigned long int. This
599 caused problems on 64-bit systems.
600
601 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
602 instance of the 'standard' template library not being so standard".
603
604 10. There was no check on the number of named subpatterns nor the maximum
605 length of a subpattern name. The product of these values is used to compute
606 the size of the memory block for a compiled pattern. By supplying a very
607 long subpattern name and a large number of named subpatterns, the size
608 computation could be caused to overflow. This is now prevented by limiting
609 the length of names to 32 characters, and the number of named subpatterns
610 to 10,000.
611
612 11. Subpatterns that are repeated with specific counts have to be replicated in
613 the compiled pattern. The size of memory for this was computed from the
614 length of the subpattern and the repeat count. The latter is limited to
615 65535, but there was no limit on the former, meaning that integer overflow
616 could in principle occur. The compiled length of a repeated subpattern is
617 now limited to 30,000 bytes in order to prevent this.
618
619 12. Added the optional facility to have named substrings with the same name.
620
621 13. Added the ability to use a named substring as a condition, using the
622 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
623 are numbers (not recommended). Forward references are permitted.
624
625 14. Added forward references in named backreferences (if you see what I mean).
626
627 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
628 pattern could run off the end of the subject. For example, the pattern
629 "(?s)(.{1,5})"8 did this with the subject "ab".
630
631 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
632 PCRE_CASELESS was set when matching characters that were quantified with ?
633 or *.
634
635 17. A character class other than a single negated character that had a minimum
636 but no maximum quantifier - for example [ab]{6,} - was not handled
637 correctly by pce_dfa_exec(). It would match only one character.
638
639 18. A valid (though odd) pattern that looked like a POSIX character
640 class but used an invalid character after [ (for example [[,abc,]]) caused
641 pcre_compile() to give the error "Failed: internal error: code overflow" or
642 in some cases to crash with a glibc free() error. This could even happen if
643 the pattern terminated after [[ but there just happened to be a sequence of
644 letters, a binary zero, and a closing ] in the memory that followed.
645
646 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
647 over the years. Originally (before any Unicode support), just the bottom 8
648 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
649 output from "man perlunicode" includes this:
650
651 The regular expression compiler produces polymorphic opcodes. That
652 is, the pattern adapts to the data and automatically switches to
653 the Unicode character scheme when presented with Unicode data--or
654 instead uses a traditional byte scheme when presented with byte
655 data.
656
657 Sadly, a wide octal escape does not cause a switch, and in a string with
658 no other multibyte characters, these octal escapes are treated as before.
659 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
660 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
661 Unicode string.
662
663 I have not perpetrated such confusion in PCRE. Up till now, it took just
664 the bottom 8 bits, as in old Perl. I have now made octal escapes with
665 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
666 translate to the appropriate multibyte character.
667
668 29. Applied some refactoring to reduce the number of warnings from Microsoft
669 and Borland compilers. This has included removing the fudge introduced
670 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
671 a warning about an unused variable.
672
673 21. PCRE has not included VT (character 0x0b) in the set of whitespace
674 characters since release 4.0, because Perl (from release 5.004) does not.
675 [Or at least, is documented not to: some releases seem to be in conflict
676 with the documentation.] However, when a pattern was studied with
677 pcre_study() and all its branches started with \s, PCRE still included VT
678 as a possible starting character. Of course, this did no harm; it just
679 caused an unnecessary match attempt.
680
681 22. Removed a now-redundant internal flag bit that recorded the fact that case
682 dependency changed within the pattern. This was once needed for "required
683 byte" processing, but is no longer used. This recovers a now-scarce options
684 bit. Also moved the least significant internal flag bit to the most-
685 significant bit of the word, which was not previously used (hangover from
686 the days when it was an int rather than a uint) to free up another bit for
687 the future.
688
689 23. Added support for CRLF line endings as well as CR and LF. As well as the
690 default being selectable at build time, it can now be changed at runtime
691 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
692 specify that it is scanning data with non-default line endings.
693
694 24. Changed the definition of CXXLINK to make it agree with the definition of
695 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
696
697 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
698 recursions. This makes a big different to stack usage for some patterns.
699
700 26. If a subpattern containing a named recursion or subroutine reference such
701 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
702 the space required for the compiled pattern went wrong and gave too small a
703 value. Depending on the environment, this could lead to "Failed: internal
704 error: code overflow at offset 49" or "glibc detected double free or
705 corruption" errors.
706
707 27. Applied patches from Google (a) to support the new newline modes and (b) to
708 advance over multibyte UTF-8 characters in GlobalReplace.
709
710 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
711 difference for some implementation of PCRE in some Windows version.
712
713 29. Added some extra testing facilities to pcretest:
714
715 \q<number> in a data line sets the "match limit" value
716 \Q<number> in a data line sets the "match recursion limt" value
717 -S <number> sets the stack size, where <number> is in megabytes
718
719 The -S option isn't available for Windows.
720
721
722 Version 6.6 06-Feb-06
723 ---------------------
724
725 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
726 in pcreposix.h. I have copied the definition from pcre.h.
727
728 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
729 because pcre.h is no longer a built file.
730
731 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
732 not normally included in the compiled code.
733
734
735 Version 6.5 01-Feb-06
736 ---------------------
737
738 1. When using the partial match feature with pcre_dfa_exec(), it was not
739 anchoring the second and subsequent partial matches at the new starting
740 point. This could lead to incorrect results. For example, with the pattern
741 /1234/, partially matching against "123" and then "a4" gave a match.
742
743 2. Changes to pcregrep:
744
745 (a) All non-match returns from pcre_exec() were being treated as failures
746 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
747 error message is output. Some extra information is given for the
748 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
749 probably the only errors that are likely to be caused by users (by
750 specifying a regex that has nested indefinite repeats, for instance).
751 If there are more than 20 of these errors, pcregrep is abandoned.
752
753 (b) A binary zero was treated as data while matching, but terminated the
754 output line if it was written out. This has been fixed: binary zeroes
755 are now no different to any other data bytes.
756
757 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
758 used to set a locale for matching. The --locale=xxxx long option has
759 been added (no short equivalent) to specify a locale explicitly on the
760 pcregrep command, overriding the environment variables.
761
762 (d) When -B was used with -n, some line numbers in the output were one less
763 than they should have been.
764
765 (e) Added the -o (--only-matching) option.
766
767 (f) If -A or -C was used with -c (count only), some lines of context were
768 accidentally printed for the final match.
769
770 (g) Added the -H (--with-filename) option.
771
772 (h) The combination of options -rh failed to suppress file names for files
773 that were found from directory arguments.
774
775 (i) Added the -D (--devices) and -d (--directories) options.
776
777 (j) Added the -F (--fixed-strings) option.
778
779 (k) Allow "-" to be used as a file name for -f as well as for a data file.
780
781 (l) Added the --colo(u)r option.
782
783 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
784 is not present by default.
785
786 3. A nasty bug was discovered in the handling of recursive patterns, that is,
787 items such as (?R) or (?1), when the recursion could match a number of
788 alternatives. If it matched one of the alternatives, but subsequently,
789 outside the recursion, there was a failure, the code tried to back up into
790 the recursion. However, because of the way PCRE is implemented, this is not
791 possible, and the result was an incorrect result from the match.
792
793 In order to prevent this happening, the specification of recursion has
794 been changed so that all such subpatterns are automatically treated as
795 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
796
797 4. I had overlooked the fact that, in some locales, there are characters for
798 which isalpha() is true but neither isupper() nor islower() are true. In
799 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
800 and ordfeminine) are like this. This affected the treatment of \w and \W
801 when they appeared in character classes, but not when they appeared outside
802 a character class. The bit map for "word" characters is now created
803 separately from the results of isalnum() instead of just taking it from the
804 upper, lower, and digit maps. (Plus the underscore character, of course.)
805
806 5. The above bug also affected the handling of POSIX character classes such as
807 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
808 permanent tables. Instead, the bit maps for such a class were previously
809 created as the appropriate unions of the upper, lower, and digit bitmaps.
810 Now they are created by subtraction from the [[:word:]] class, which has
811 its own bitmap.
812
813 6. The [[:blank:]] character class matches horizontal, but not vertical space.
814 It is created by subtracting the vertical space characters (\x09, \x0a,
815 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
816 subtraction was done in the overall bitmap for a character class, meaning
817 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
818 be recognized. This bug has been fixed.
819
820 7. Patches from the folks at Google:
821
822 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
823 real life, but is still worth protecting against".
824
825 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
826 regular expressions".
827
828 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
829 have it.
830
831 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
832 "configure" and the latter not, in order to fix a problem somebody had
833 with compiling the Arg class on HP-UX.
834
835 (e) Improve the error-handling of the C++ wrapper a little bit.
836
837 (f) New tests for checking recursion limiting.
838
839 8. The pcre_memmove() function, which is used only if the environment does not
840 have a standard memmove() function (and is therefore rarely compiled),
841 contained two bugs: (a) use of int instead of size_t, and (b) it was not
842 returning a result (though PCRE never actually uses the result).
843
844 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
845 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
846 returned instead of calling malloc() with an overflowing number that would
847 most likely cause subsequent chaos.
848
849 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
850
851 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
852 with this option is matched, the nmatch and pmatch options of regexec() are
853 ignored.
854
855 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
856 provided in case anyone wants to the the POSIX interface with UTF-8
857 strings.
858
859 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
860 C++ linking (needed for some HP-UX environments).
861
862 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
863 (unused parameter) and in the pcre_printint() function (omitted "default"
864 switch label when the default is to do nothing).
865
866 15. Added some code to make it possible, when PCRE is compiled as a C++
867 library, to replace subject pointers for pcre_exec() with a smart pointer
868 class, thus making it possible to process discontinuous strings.
869
870 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
871 much the same function. They were added by different people who were trying
872 to make PCRE easy to compile on non-Unix systems. It has been suggested
873 that PCRE_EXPORT be abolished now that there is more automatic apparatus
874 for compiling on Windows systems. I have therefore replaced it with
875 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
876 defaults to "extern" for C or "extern C" for C++, which works fine on
877 Unix-like systems. It is now possible to override the value of PCRE_DATA_
878 SCOPE with something explicit in config.h. In addition:
879
880 (a) pcreposix.h still had just "extern" instead of either of these macros;
881 I have replaced it with PCRE_DATA_SCOPE.
882
883 (b) Functions such as _pcre_xclass(), which are internal to the library,
884 but external in the C sense, all had PCRE_EXPORT in their definitions.
885 This is apparently wrong for the Windows case, so I have removed it.
886 (It makes no difference on Unix-like systems.)
887
888 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
889 of recursive calls to match(). This is different to MATCH_LIMIT because
890 that limits the total number of calls to match(), not all of which increase
891 the depth of recursion. Limiting the recursion depth limits the amount of
892 stack (or heap if NO_RECURSE is set) that is used. The default can be set
893 when PCRE is compiled, and changed at run time. A patch from Google adds
894 this functionality to the C++ interface.
895
896 18. Changes to the handling of Unicode character properties:
897
898 (a) Updated the table to Unicode 4.1.0.
899
900 (b) Recognize characters that are not in the table as "Cn" (undefined).
901
902 (c) I revised the way the table is implemented to a much improved format
903 which includes recognition of ranges. It now supports the ranges that
904 are defined in UnicodeData.txt, and it also amalgamates other
905 characters into ranges. This has reduced the number of entries in the
906 table from around 16,000 to around 3,000, thus reducing its size
907 considerably. I realized I did not need to use a tree structure after
908 all - a binary chop search is just as efficient. Having reduced the
909 number of entries, I extended their size from 6 bytes to 8 bytes to
910 allow for more data.
911
912 (d) Added support for Unicode script names via properties such as \p{Han}.
913
914 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
915 matching that character.
916
917 20. When matching a repeated Unicode property with a minimum greater than zero,
918 (for example \pL{2,}), PCRE could look past the end of the subject if it
919 reached it while seeking the minimum number of characters. This could
920 happen only if some of the characters were more than one byte long, because
921 there is a check for at least the minimum number of bytes.
922
923 21. Refactored the implementation of \p and \P so as to be more general, to
924 allow for more different types of property in future. This has changed the
925 compiled form incompatibly. Anybody with saved compiled patterns that use
926 \p or \P will have to recompile them.
927
928 22. Added "Any" and "L&" to the supported property types.
929
930 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
931 but give a compile time error if the value is greater than 0xff.
932
933 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
934 accidentally not being installed or uninstalled.
935
936 25. The pcre.h file was built from pcre.h.in, but the only changes that were
937 made were to insert the current release number. This seemed silly, because
938 it made things harder for people building PCRE on systems that don't run
939 "configure". I have turned pcre.h into a distributed file, no longer built
940 by "configure", with the version identification directly included. There is
941 no longer a pcre.h.in file.
942
943 However, this change necessitated a change to the pcre-config script as
944 well. It is built from pcre-config.in, and one of the substitutions was the
945 release number. I have updated configure.ac so that ./configure now finds
946 the release number by grepping pcre.h.
947
948 26. Added the ability to run the tests under valgrind.
949
950
951 Version 6.4 05-Sep-05
952 ---------------------
953
954 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
955 "--" to be printed when multiple files were scanned, even when none of the
956 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
957 consider it to be a bug, and have restored the previous behaviour.
958
959 2. A couple of code tidies to get rid of compiler warnings.
960
961 3. The pcretest program used to cheat by referring to symbols in the library
962 whose names begin with _pcre_. These are internal symbols that are not
963 really supposed to be visible externally, and in some environments it is
964 possible to suppress them. The cheating is now confined to including
965 certain files from the library's source, which is a bit cleaner.
966
967 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
968 file's purpose clearer.
969
970 5. Reorganized pcre_ucp_findchar().
971
972
973 Version 6.3 15-Aug-05
974 ---------------------
975
976 1. The file libpcre.pc.in did not have general read permission in the tarball.
977
978 2. There were some problems when building without C++ support:
979
980 (a) If C++ support was not built, "make install" and "make test" still
981 tried to test it.
982
983 (b) There were problems when the value of CXX was explicitly set. Some
984 changes have been made to try to fix these, and ...
985
986 (c) --disable-cpp can now be used to explicitly disable C++ support.
987
988 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
989 backslash in a target when C++ was disabled. This confuses some
990 versions of "make", apparently. Using an intermediate variable solves
991 this. (Same for CPP_LOBJ.)
992
993 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
994 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
995 necessary on certain architectures.
996
997 4. Added a setting of -export-symbols-regex to the link command to remove
998 those symbols that are exported in the C sense, but actually are local
999 within the library, and not documented. Their names all begin with
1000 "_pcre_". This is not a perfect job, because (a) we have to except some
1001 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1002 available (and never for static libraries). I have made a note to try to
1003 find a way round (a) in the future.
1004
1005
1006 Version 6.2 01-Aug-05
1007 ---------------------
1008
1009 1. There was no test for integer overflow of quantifier values. A construction
1010 such as {1111111111111111} would give undefined results. What is worse, if
1011 a minimum quantifier for a parenthesized subpattern overflowed and became
1012 negative, the calculation of the memory size went wrong. This could have
1013 led to memory overwriting.
1014
1015 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1016
1017 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1018 operating environments where this matters.
1019
1020 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1021 PCRE options from within the C++ wrapper.
1022
1023 5. Named capturing subpatterns were not being correctly counted when a pattern
1024 was compiled. This caused two problems: (a) If there were more than 100
1025 such subpatterns, the calculation of the memory needed for the whole
1026 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1027 back references of the form \12, where the number was greater than 9, were
1028 not recognized as back references, even though there were sufficient
1029 previous subpatterns.
1030
1031 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1032 versions of gcc, e.g. 2.95.4.
1033
1034
1035 Version 6.1 21-Jun-05
1036 ---------------------
1037
1038 1. There was one reference to the variable "posix" in pcretest.c that was not
1039 surrounded by "#if !defined NOPOSIX".
1040
1041 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1042 the cross-check on the old pcre_info() function, for the benefit of the
1043 cut-down version of PCRE that is currently imported into Exim.
1044
1045 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1046 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1047 patterns that start (?i) but I don't think that matters. The use of (?i) is
1048 just an example; this all applies to the other options as well.
1049
1050 4. Since libtool seems to echo the compile commands it is issuing, the output
1051 from "make" can be reduced a bit by putting "@" in front of each libtool
1052 compile command.
1053
1054 5. Patch from the folks at Google for configure.in to be a bit more thorough
1055 in checking for a suitable C++ installation before trying to compile the
1056 C++ stuff. This should fix a reported problem when a compiler was present,
1057 but no suitable headers.
1058
1059 6. The man pages all had just "PCRE" as their title. I have changed them to
1060 be the relevant file name. I have also arranged that these names are
1061 retained in the file doc/pcre.txt, which is a concatenation in text format
1062 of all the man pages except the little individual ones for each function.
1063
1064 7. The NON-UNIX-USE file had not been updated for the different set of source
1065 files that come with release 6. I also added a few comments about the C++
1066 wrapper.
1067
1068
1069 Version 6.0 07-Jun-05
1070 ---------------------
1071
1072 1. Some minor internal re-organization to help with my DFA experiments.
1073
1074 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1075 didn't matter for the library itself when fully configured, but did matter
1076 when compiling without UCP support, or within Exim, where the ucp files are
1077 not imported.
1078
1079 3. Refactoring of the library code to split up the various functions into
1080 different source modules. The addition of the new DFA matching code (see
1081 below) to a single monolithic source would have made it really too
1082 unwieldy, quite apart from causing all the code to be include in a
1083 statically linked application, when only some functions are used. This is
1084 relevant even without the DFA addition now that patterns can be compiled in
1085 one application and matched in another.
1086
1087 The downside of splitting up is that there have to be some external
1088 functions and data tables that are used internally in different modules of
1089 the library but which are not part of the API. These have all had their
1090 names changed to start with "_pcre_" so that they are unlikely to clash
1091 with other external names.
1092
1093 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1094 a different (DFA) algorithm. Although it is slower than the original
1095 function, it does have some advantages for certain types of matching
1096 problem.
1097
1098 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1099 including restarting after a partial match.
1100
1101 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1102 defined when compiling for Windows was sent to me. I have put it into the
1103 code, though I have no means of testing or verifying it.
1104
1105 7. Added the pcre_refcount() auxiliary function.
1106
1107 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1108 match before or at the first newline in the subject string. In pcretest,
1109 the /f option on a pattern can be used to set this.
1110
1111 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1112 would behave wrongly. This has been present in PCRE since release 4.0.
1113
1114 10. A number of changes to the pcregrep command:
1115
1116 (a) Refactored how -x works; insert ^(...)$ instead of setting
1117 PCRE_ANCHORED and checking the length, in preparation for adding
1118 something similar for -w.
1119
1120 (b) Added the -w (match as a word) option.
1121
1122 (c) Refactored the way lines are read and buffered so as to have more
1123 than one at a time available.
1124
1125 (d) Implemented a pcregrep test script.
1126
1127 (e) Added the -M (multiline match) option. This allows patterns to match
1128 over several lines of the subject. The buffering ensures that at least
1129 8K, or the rest of the document (whichever is the shorter) is available
1130 for matching (and similarly the previous 8K for lookbehind assertions).
1131
1132 (f) Changed the --help output so that it now says
1133
1134 -w, --word-regex(p)
1135
1136 instead of two lines, one with "regex" and the other with "regexp"
1137 because that confused at least one person since the short forms are the
1138 same. (This required a bit of code, as the output is generated
1139 automatically from a table. It wasn't just a text change.)
1140
1141 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1142 option but starts with a hyphen. Could be a pattern or a path name
1143 starting with a hyphen, for instance.
1144
1145 (h) "-" can be given as a file name to represent stdin.
1146
1147 (i) When file names are being printed, "(standard input)" is used for
1148 the standard input, for compatibility with GNU grep. Previously
1149 "<stdin>" was used.
1150
1151 (j) The option --label=xxx can be used to supply a name to be used for
1152 stdin when file names are being printed. There is no short form.
1153
1154 (k) Re-factored the options decoding logic because we are going to add
1155 two more options that take data. Such options can now be given in four
1156 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1157
1158 (l) Added the -A, -B, and -C options for requesting that lines of context
1159 around matches be printed.
1160
1161 (m) Added the -L option to print the names of files that do not contain
1162 any matching lines, that is, the complement of -l.
1163
1164 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1165 continue to scan other files.
1166
1167 (o) The -s option was incorrectly implemented. For compatibility with other
1168 greps, it now suppresses the error message for a non-existent or non-
1169 accessible file (but not the return code). There is a new option called
1170 -q that suppresses the output of matching lines, which was what -s was
1171 previously doing.
1172
1173 (p) Added --include and --exclude options to specify files for inclusion
1174 and exclusion when recursing.
1175
1176 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1177 Hopefully, it now does.
1178
1179 12. Missing cast in pcre_study().
1180
1181 13. Added an "uninstall" target to the makefile.
1182
1183 14. Replaced "extern" in the function prototypes in Makefile.in with
1184 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1185 world, but is set differently for Windows.
1186
1187 15. Added a second compiling function called pcre_compile2(). The only
1188 difference is that it has an extra argument, which is a pointer to an
1189 integer error code. When there is a compile-time failure, this is set
1190 non-zero, in addition to the error test pointer being set to point to an
1191 error message. The new argument may be NULL if no error number is required
1192 (but then you may as well call pcre_compile(), which is now just a
1193 wrapper). This facility is provided because some applications need a
1194 numeric error indication, but it has also enabled me to tidy up the way
1195 compile-time errors are handled in the POSIX wrapper.
1196
1197 16. Added VPATH=.libs to the makefile; this should help when building with one
1198 prefix path and installing with another. (Or so I'm told by someone who
1199 knows more about this stuff than I do.)
1200
1201 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1202 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1203 match everything, including newlines. This is not POSIX-compatible, but
1204 somebody wanted the feature. From pcretest it can be activated by using
1205 both the P and the s flags.
1206
1207 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1208
1209 19. libpcre.pc was being incorrectly installed as executable.
1210
1211 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1212 it now also looks for '\r' so that it will work unmodified on Windows.
1213
1214 21. Added Google's contributed C++ wrapper to the distribution.
1215
1216 22. Added some untidy missing memory free() calls in pcretest, to keep
1217 Electric Fence happy when testing.
1218
1219
1220
1221 Version 5.0 13-Sep-04
1222 ---------------------
1223
1224 1. Internal change: literal characters are no longer packed up into items
1225 containing multiple characters in a single byte-string. Each character
1226 is now matched using a separate opcode. However, there may be more than one
1227 byte in the character in UTF-8 mode.
1228
1229 2. The pcre_callout_block structure has two new fields: pattern_position and
1230 next_item_length. These contain the offset in the pattern to the next match
1231 item, and its length, respectively.
1232
1233 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1234 insertion of callouts before each pattern item. Added the /C option to
1235 pcretest to make use of this.
1236
1237 4. On the advice of a Windows user, the lines
1238
1239 #if defined(_WIN32) || defined(WIN32)
1240 _setmode( _fileno( stdout ), 0x8000 );
1241 #endif /* defined(_WIN32) || defined(WIN32) */
1242
1243 have been added to the source of pcretest. This apparently does useful
1244 magic in relation to line terminators.
1245
1246 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1247 for the benefit of those environments where the "b" makes a difference.
1248
1249 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1250 to know about it. I have put a hack into configure.in that adds in code
1251 to set GCC=yes if CC=icc. This seems to end up at a point in the
1252 generated configure script that is early enough to affect the setting of
1253 compiler options, which is what is needed, but I have no means of testing
1254 whether it really works. (The user who reported this had patched the
1255 generated configure script, which of course I cannot do.)
1256
1257 LATER: After change 22 below (new libtool files), the configure script
1258 seems to know about icc (and also ecc). Therefore, I have commented out
1259 this hack in configure.in.
1260
1261 7. Added support for pkg-config (2 patches were sent in).
1262
1263 8. Negated POSIX character classes that used a combination of internal tables
1264 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1265 [[:^ascii]]. Typically, they would match almost any characters. The other
1266 POSIX classes were not broken in this way.
1267
1268 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1269 to find the match, as PCRE was deluded into thinking that the match had to
1270 start at the start point or following a newline. The same bug applied to
1271 patterns with negative forward assertions or any backward assertions
1272 preceding ".*" at the start, unless the pattern required a fixed first
1273 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1274
1275 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1276 starting at the last subject character, bytes beyond the end of the subject
1277 string were read.
1278
1279 11. Renamed the variable "class" as "classbits" to make life easier for C++
1280 users. (Previously there was a macro definition, but it apparently wasn't
1281 enough.)
1282
1283 12. Added the new field "tables" to the extra data so that tables can be passed
1284 in at exec time, or the internal tables can be re-selected. This allows
1285 a compiled regex to be saved and re-used at a later time by a different
1286 program that might have everything at different addresses.
1287
1288 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1289 -R library as well as a -L library.
1290
1291 14. The debugging options of pcretest (-d on the command line or D on a
1292 pattern) showed incorrect output for anything following an extended class
1293 that contained multibyte characters and which was followed by a quantifier.
1294
1295 15. Added optional support for general category Unicode character properties
1296 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1297 support. It adds about 90K to the size of the library. The meanings of the
1298 inbuilt class escapes such as \d and \s have NOT been changed.
1299
1300 16. Updated pcredemo.c to include calls to free() to release the memory for the
1301 compiled pattern.
1302
1303 17. The generated file chartables.c was being created in the source directory
1304 instead of in the building directory. This caused the build to fail if the
1305 source directory was different from the building directory, and was
1306 read-only.
1307
1308 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1309 file. No doubt somebody will tell me if they don't make sense... Also added
1310 Dan Mooney's comments about building on OpenVMS.
1311
1312 19. Added support for partial matching via the PCRE_PARTIAL option for
1313 pcre_exec() and the \P data escape in pcretest.
1314
1315 20. Extended pcretest with 3 new pattern features:
1316
1317 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1318 write the compiled pattern to the file whose name is "rest-of-line".
1319 This is a straight binary dump of the data, with the saved pointer to
1320 the character tables forced to be NULL. The study data, if any, is
1321 written too. After writing, pcretest reads a new pattern.
1322
1323 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1324 compiled pattern from the given file. There must not be any
1325 occurrences of "<" in the file name (pretty unlikely); if there are,
1326 pcretest will instead treat the initial "<" as a pattern delimiter.
1327 After reading in the pattern, pcretest goes on to read data lines as
1328 usual.
1329
1330 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1331 and 16-bit fields in a compiled pattern, to simulate a pattern that
1332 was compiled on a host of opposite endianness.
1333
1334 21. The pcre-exec() function can now cope with patterns that were compiled on
1335 hosts of opposite endianness, with this restriction:
1336
1337 As for any compiled expression that is saved and used later, the tables
1338 pointer field cannot be preserved; the extra_data field in the arguments
1339 to pcre_exec() should be used to pass in a tables address if a value
1340 other than the default internal tables were used at compile time.
1341
1342 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1343 now diagnosed as an error. Previously, most of the time, a negative number
1344 would have been treated as zero, but if in addition "ovector" was passed as
1345 NULL, a crash could occur.
1346
1347 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1348 new versions from the libtool 1.5 distribution (the last one is a copy of
1349 a file called libtool.m4). This seems to have fixed the need to patch
1350 "configure" to support Darwin 1.3 (which I used to do). However, I still
1351 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1352 workstation).
1353
1354 24. Changed the PCRE licence to be the more standard "BSD" licence.
1355
1356
1357 Version 4.5 01-Dec-03
1358 ---------------------
1359
1360 1. There has been some re-arrangement of the code for the match() function so
1361 that it can be compiled in a version that does not call itself recursively.
1362 Instead, it keeps those local variables that need separate instances for
1363 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1364 needs to "recurse". Keeping track of where control must go is done by means
1365 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1366 hide most of the details from the main code, and operates only if
1367 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1368 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1369 operating.
1370
1371 To make it easier for callers to provide specially tailored get/free
1372 functions for this usage, two new functions, pcre_stack_malloc, and
1373 pcre_stack_free, are used. They are always called in strict stacking order,
1374 and the size of block requested is always the same.
1375
1376 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1377 PCRE has been compiled to use the stack or the heap for recursion. The
1378 -C option of pcretest uses this to show which version is compiled.
1379
1380 A new data escape \S, is added to pcretest; it causes the amounts of store
1381 obtained and freed by both kinds of malloc/free at match time to be added
1382 to the output.
1383
1384 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1385 what's available on my current Linux desktop machine.
1386
1387 3. When matching a UTF-8 string, the test for a valid string at the start has
1388 been extended. If start_offset is not zero, PCRE now checks that it points
1389 to a byte that is the start of a UTF-8 character. If not, it returns
1390 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1391 this is necessary because there may be backward assertions in the pattern.
1392 When matching the same subject several times, it may save resources to use
1393 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1394
1395 4. The code for checking the validity of UTF-8 strings has been tightened so
1396 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1397 containing "overlong sequences".
1398
1399 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1400 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1401 should have been "&", but it just so happened that all the cases this let
1402 through by mistake were picked up later in the function.
1403
1404 6. I had used a variable called "isblank" - this is a C99 function, causing
1405 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1406
1407 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1408 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1409 so the version is shown; (c) stop "make test" echoing "./RunTest".
1410
1411 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1412
1413 9. The prototype for memmove() for systems that don't have it was using
1414 size_t, but the inclusion of the header that defines size_t was later. I've
1415 moved the #includes for the C headers earlier to avoid this.
1416
1417 10. Added some adjustments to the code to make it easier to compiler on certain
1418 special systems:
1419
1420 (a) Some "const" qualifiers were missing.
1421 (b) Added the macro EXPORT before all exported functions; by default this
1422 is defined to be empty.
1423 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1424 that it reads its output file name as an argument instead of writing
1425 to the standard output and assuming this can be redirected.
1426
1427 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1428 class containing characters with values greater than 255, PCRE compilation
1429 went into a loop.
1430
1431 12. A recursive reference to a subpattern that was within another subpattern
1432 that had a minimum quantifier of zero caused PCRE to crash. For example,
1433 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1434 recursion. If the recursively-called subpattern itself had a zero repeat,
1435 that was OK.
1436
1437 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1438 buffer into which it was copied (for escape processing) was still set at
1439 1024, so long lines caused crashes.
1440
1441 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1442 "internal error: code overflow...". This applied to any character class
1443 that was followed by a possessive quantifier.
1444
1445 15. Modified the Makefile to add libpcre.la as a prerequisite for
1446 libpcreposix.la because I was told this is needed for a parallel build to
1447 work.
1448
1449 16. If a pattern that contained .* following optional items at the start was
1450 studied, the wrong optimizing data was generated, leading to matching
1451 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1452 matching string must start with a or b or c. The correct conclusion for
1453 this pattern is that a match can start with any character.
1454
1455
1456 Version 4.4 13-Aug-03
1457 ---------------------
1458
1459 1. In UTF-8 mode, a character class containing characters with values between
1460 127 and 255 was not handled correctly if the compiled pattern was studied.
1461 In fixing this, I have also improved the studying algorithm for such
1462 classes (slightly).
1463
1464 2. Three internal functions had redundant arguments passed to them. Removal
1465 might give a very teeny performance improvement.
1466
1467 3. Documentation bug: the value of the capture_top field in a callout is *one
1468 more than* the number of the hightest numbered captured substring.
1469
1470 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1471 in incorrectly linking with a previously installed version. They now link
1472 explicitly with libpcre.la.
1473
1474 5. configure.in no longer needs to recognize Cygwin specially.
1475
1476 6. A problem in pcre.in for Windows platforms is fixed.
1477
1478 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1479 pcretest, it used to include the size of the study block as part of its
1480 output. Unfortunately, the structure contains a field that has a different
1481 size on different hardware architectures. This meant that the tests that
1482 showed this size failed. As the block is currently always of a fixed size,
1483 this information isn't actually particularly useful in pcretest output, so
1484 I have just removed it.
1485
1486 8. Three pre-processor statements accidentally did not start in column 1.
1487 Sadly, there are *still* compilers around that complain, even though
1488 standard C has not required this for well over a decade. Sigh.
1489
1490 9. In pcretest, the code for checking callouts passed small integers in the
1491 callout_data field, which is a void * field. However, some picky compilers
1492 complained about the casts involved for this on 64-bit systems. Now
1493 pcretest passes the address of the small integer instead, which should get
1494 rid of the warnings.
1495
1496 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1497 both compile and run time, and gives an error if an invalid UTF-8 sequence
1498 is found. There is a option for disabling this check in cases where the
1499 string is known to be correct and/or the maximum performance is wanted.
1500
1501 11. In response to a bug report, I changed one line in Makefile.in from
1502
1503 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1504 to
1505 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1506
1507 to look similar to other lines, but I have no way of telling whether this
1508 is the right thing to do, as I do not use Windows. No doubt I'll get told
1509 if it's wrong...
1510
1511
1512 Version 4.3 21-May-03
1513 ---------------------
1514
1515 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1516 Makefile.
1517
1518 2. Some refactoring to improve the quality of the code:
1519
1520 (i) The utf8_table... variables are now declared "const".
1521
1522 (ii) The code for \cx, which used the "case flipping" table to upper case
1523 lower case letters, now just substracts 32. This is ASCII-specific,
1524 but the whole concept of \cx is ASCII-specific, so it seems
1525 reasonable.
1526
1527 (iii) PCRE was using its character types table to recognize decimal and
1528 hexadecimal digits in the pattern. This is silly, because it handles
1529 only 0-9, a-f, and A-F, but the character types table is locale-
1530 specific, which means strange things might happen. A private
1531 table is now used for this - though it costs 256 bytes, a table is
1532 much faster than multiple explicit tests. Of course, the standard
1533 character types table is still used for matching digits in subject
1534 strings against \d.
1535
1536 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1537 ending in _t are). So I've renamed it as ESC_tee.
1538
1539 3. The first argument for regexec() in the POSIX wrapper should have been
1540 defined as "const".
1541
1542 4. Changed pcretest to use malloc() for its buffers so that they can be
1543 Electric Fenced for debugging.
1544
1545 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1546 to read one or more bytes before the start of the subject string. Often this
1547 had no effect on PCRE's behaviour, but in some circumstances it could
1548 provoke a segmentation fault.
1549
1550 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1551 to try to read one or more bytes before the start of the subject string.
1552
1553 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1554 UTF-8 support could misbehave in various ways if the subject string
1555 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1556 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1557 back over UTF-8 characters.)
1558
1559
1560 Version 4.2 14-Apr-03
1561 ---------------------
1562
1563 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1564
1565 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1566 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1567 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1568 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1569 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1570 and BUILD_EXEEXT
1571 Note: automatic setting of the BUILD variables is not yet working
1572 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1573 compile-time but not at link-time
1574 [LINK]: use for linking executables only
1575 make different versions for Windows and non-Windows
1576 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1577 libraries
1578 [LINK_FOR_BUILD]: new variable
1579 [OBJEXT]: use throughout
1580 [EXEEXT]: use throughout
1581 <winshared>: new target
1582 <wininstall>: new target
1583 <dftables.o>: use native compiler
1584 <dftables>: use native linker
1585 <install>: handle Windows platform correctly
1586 <clean>: ditto
1587 <check>: ditto
1588 copy DLL to top builddir before testing
1589
1590 As part of these changes, -no-undefined was removed again. This was reported
1591 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1592 in any case.
1593
1594 3. Some tidies to get rid of compiler warnings:
1595
1596 . In the match_data structure, match_limit was an unsigned long int, whereas
1597 match_call_count was an int. I've made them both unsigned long ints.
1598
1599 . In pcretest the fact that a const uschar * doesn't automatically cast to
1600 a void * provoked a warning.
1601
1602 . Turning on some more compiler warnings threw up some "shadow" variables
1603 and a few more missing casts.
1604
1605 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1606 option, a class that contained a single character with a value between 128
1607 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1608
1609 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1610 option, a class that contained several characters, but with at least one
1611 whose value was between 128 and 255 caused PCRE to crash.
1612
1613
1614 Version 4.1 12-Mar-03
1615 ---------------------
1616
1617 1. Compiling with gcc -pedantic found a couple of places where casts were
1618 needed, and a string in dftables.c that was longer than standard compilers are
1619 required to support.
1620
1621 2. Compiling with Sun's compiler found a few more places where the code could
1622 be tidied up in order to avoid warnings.
1623
1624 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1625 first of these names is deprecated in the latest Autoconf in favour of the name
1626 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1627 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1628 analogy I have changed it to CFLAGS_FOR_BUILD.
1629
1630 4. Added -no-undefined to the linking command in the Makefile, because this is
1631 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1632 linking step for the pcreposix library.
1633
1634 5. PCRE was failing to diagnose the case of two named groups with the same
1635 name.
1636
1637 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1638 literal character that is needed in the subject for a match, and scans along to
1639 ensure that it is present before embarking on the full matching process. This
1640 saves time in cases of nested unlimited repeats that are never going to match.
1641 Problem: the scan can take a lot of time if the subject is very long (e.g.
1642 megabytes), thus penalizing straightforward matches. It is now done only if the
1643 amount of subject to be scanned is less than 1000 bytes.
1644
1645 7. A lesser problem with the same optimization is that it was recording the
1646 first character of an anchored pattern as "needed", thus provoking a search
1647 right along the subject, even when the first match of the pattern was going to
1648 fail. The "needed" character is now not set for anchored patterns, unless it
1649 follows something in the pattern that is of non-fixed length. Thus, it still
1650 fulfils its original purpose of finding quick non-matches in cases of nested
1651 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1652
1653
1654 Version 4.0 17-Feb-03
1655 ---------------------
1656
1657 1. If a comment in an extended regex that started immediately after a meta-item
1658 extended to the end of string, PCRE compiled incorrect data. This could lead to
1659 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1660
1661 2. Moved to autoconf 2.53 and libtool 1.4.2.
1662
1663 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1664 the special perltest8 script is no longer needed - all the tests can be run
1665 from a single perltest script.
1666
1667 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1668 by \s. It has now been removed in PCRE. This means it isn't recognized as
1669 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1670 class [:space:] *does* include VT, thereby creating a mess.
1671
1672 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1673 space and tab.
1674
1675 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1676 its new features into the main test script, reducing the number of scripts.
1677
1678 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1679 were backward compatible, and made the (?i) apply to the whole pattern, as if
1680 /i were given. Now it behaves more logically, and applies the option setting
1681 only to what follows. PCRE has been changed to follow suit. However, if it
1682 finds options settings right at the start of the pattern, it extracts them into
1683 the global options, as before. Thus, they show up in the info data.
1684
1685 8. Added support for the \Q...\E escape sequence. Characters in between are
1686 treated as literals. This is slightly different from Perl in that $ and @ are
1687 also handled as literals inside the quotes. In Perl, they will cause variable
1688 interpolation. Note the following examples:
1689
1690 Pattern PCRE matches Perl matches
1691
1692 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1693 \Qabc\$xyz\E abc\$xyz abc\$xyz
1694 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1695
1696 For compatibility with Perl, \Q...\E sequences are recognized inside character
1697 classes as well as outside them.
1698
1699 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1700 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1701 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1702 signed/unsigned warnings.
1703
1704 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1705 option for pcretest, so I've replaced it by a simple function that does just
1706 that job.
1707
1708 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1709 "pcregrep -".
1710
1711 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1712 Java package. This provides some syntactic sugar for simple cases of what my
1713 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1714 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1715 item, you can use this simplified notation. Note that only makes sense with
1716 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1717 greediness, whatever the setting of the PCRE_UNGREEDY option.
1718
1719 13. A change of greediness default within a pattern was not taking effect at
1720 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1721 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1722 was abstracted outside.
1723
1724 14. PCRE now supports the \G assertion. It is true when the current matching
1725 position is at the start point of the match. This differs from \A when the
1726 starting offset is non-zero. Used with the /g option of pcretest (or similar
1727 code), it works in the same way as it does for Perl's /g option. If all
1728 alternatives of a regex begin with \G, the expression is anchored to the start
1729 match position, and the "anchored" flag is set in the compiled expression.
1730
1731 15. Some bugs concerning the handling of certain option changes within patterns
1732 have been fixed. These applied to options other than (?ims). For example,
1733 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1734 been the other way round. Some of this was related to change 7 above.
1735
1736 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1737 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1738 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1739 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1740
1741 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1742 mode. Unlike ".", it always matches newline, whatever the setting of
1743 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1744 assertions. Perl allows it, but it doesn't (in general) work because it can't
1745 calculate the length of the lookbehind. At least, that's the case for Perl
1746 5.8.0 - I've been told they are going to document that it doesn't work in
1747 future.
1748
1749 18. Added an error diagnosis for escapes that PCRE does not support: these are
1750 \L, \l, \N, \P, \p, \U, \u, and \X.
1751
1752 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1753 reading past the end of the pattern in cases such as /[abcd/.
1754
1755 20. PCRE was getting more memory than necessary for patterns with classes that
1756 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1757
1758 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1759 compiling PCRE for use with Virtual Pascal.
1760
1761 22. Small fix to the Makefile to make it work properly if the build is done
1762 outside the source tree.
1763
1764 23. Added a new extension: a condition to go with recursion. If a conditional
1765 subpattern starts with (?(R) the "true" branch is used if recursion has
1766 happened, whereas the "false" branch is used only at the top level.
1767
1768 24. When there was a very long string of literal characters (over 255 bytes
1769 without UTF support, over 250 bytes with UTF support), the computation of how
1770 much memory was required could be incorrect, leading to segfaults or other
1771 strange effects.
1772
1773 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1774 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1775 there was a subsequent back reference to those brackets. This meant that, for
1776 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1777 possible to check for precisely this case. All we can do is abandon the
1778 optimization if .* occurs inside capturing brackets when there are any back
1779 references whatsoever. (See below for a better fix that came later.)
1780
1781 26. The handling of the optimization for finding the first character of a
1782 non-anchored pattern, and for finding a character that is required later in the
1783 match were failing in some cases. This didn't break the matching; it just
1784 failed to optimize when it could. The way this is done has been re-implemented.
1785
1786 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1787
1788 28. Added a new feature that provides some of the functionality that Perl
1789 provides with (?{...}). The facility is termed a "callout". The way it is done
1790 in PCRE is for the caller to provide an optional function, by setting
1791 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1792 global variable. By default it is unset, which disables all calling out. To get
1793 the function called, the regex must include (?C) at appropriate points. This
1794 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1795 This provides a means of identifying different callout points. When PCRE
1796 reaches such a point in the regex, if pcre_callout has been set, the external
1797 function is called. It is provided with data in a structure called
1798 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1799 matching continues; if it returns a non-zero value, the match at the current
1800 point fails. However, backtracking will occur if possible. [This was changed
1801 later and other features added - see item 49 below.]
1802
1803 29. pcretest is upgraded to test the callout functionality. It provides a
1804 callout function that displays information. By default, it shows the start of
1805 the match and the current position in the text. There are some new data escapes
1806 to vary what happens:
1807
1808 \C+ in addition, show current contents of captured substrings
1809 \C- do not supply a callout function
1810 \C!n return 1 when callout number n is reached
1811 \C!n!m return 1 when callout number n is reached for the mth time
1812
1813 30. If pcregrep was called with the -l option and just a single file name, it
1814 output "<stdin>" if a match was found, instead of the file name.
1815
1816 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1817 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1818 pcre_exec(). This saves a malloc/free per call. The default value of
1819 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1820 when configuring.
1821
1822 32. The default maximum size of a compiled pattern is 64K. There have been a
1823 few cases of people hitting this limit. The code now uses macros to handle the
1824 storing of links as offsets within the compiled pattern. It defaults to 2-byte
1825 links, but this can be changed to 3 or 4 bytes by --with-link-size when
1826 configuring. Tests 2 and 5 work only with 2-byte links because they output
1827 debugging information about compiled patterns.
1828
1829 33. Internal code re-arrangements:
1830
1831 (a) Moved the debugging function for printing out a compiled regex into
1832 its own source file (printint.c) and used #include to pull it into
1833 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1834 separate copies.
1835
1836 (b) Defined the list of op-code names for debugging as a macro in
1837 internal.h so that it is next to the definition of the opcodes.
1838
1839 (c) Defined a table of op-code lengths for simpler skipping along compiled
1840 code. This is again a macro in internal.h so that it is next to the
1841 definition of the opcodes.
1842
1843 34. Added support for recursive calls to individual subpatterns, along the
1844 lines of Robin Houston's patch (but implemented somewhat differently).
1845
1846 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1847 allow it to read and process whole directories in Win32. This code was
1848 contributed by Lionel Fourquaux; it has not been tested by me.
1849
1850 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1851 used to name a group. Names consist of alphanumerics and underscores, and must
1852 be unique. Back references use the syntax (?P=name) and recursive calls use
1853 (?P>name) which is a PCRE extension to the Python extension. Groups still have
1854 numbers. The function pcre_fullinfo() can be used after compilation to extract
1855 a name/number map. There are three relevant calls:
1856
1857 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
1858 PCRE_INFO_NAMECOUNT yields the number of entries
1859 PCRE_INFO_NAMETABLE yields a pointer to the map.
1860
1861 The map is a vector of fixed-size entries. The size of each entry depends on
1862 the length of the longest name used. The first two bytes of each entry are the
1863 group number, most significant byte first. There follows the corresponding
1864 name, zero terminated. The names are in alphabetical order.
1865
1866 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1867 case instead of 255. Making it the same both with and without UTF-8 support
1868 means that the same test output works with both.
1869
1870 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1871 calling malloc() with a zero argument.
1872
1873 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1874 optimization. I've improved things by keeping a bitmap of backreferences with
1875 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1876 fact referenced, the optimization can be applied. It is unlikely that a
1877 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1878 the match to follow \n) will appear inside brackets with a number greater than
1879 31, but if it does, any back reference > 31 suppresses the optimization.
1880
1881 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1882 of disabling numbered capturing parentheses. Any opening parenthesis that is
1883 not followed by ? behaves as if it were followed by ?: but named parentheses
1884 can still be used for capturing (and they will acquire numbers in the usual
1885 way).
1886
1887 41. Redesigned the return codes from the match() function into yes/no/error so
1888 that errors can be passed back from deep inside the nested calls. A malloc
1889 failure while inside a recursive subpattern call now causes the
1890 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1891
1892 42. It is now possible to set a limit on the number of times the match()
1893 function is called in a call to pcre_exec(). This facility makes it possible to
1894 limit the amount of recursion and backtracking, though not in a directly
1895 obvious way, because the match() function is used in a number of different
1896 circumstances. The count starts from zero for each position in the subject
1897 string (for non-anchored patterns). The default limit is, for compatibility, a
1898 large number, namely 10 000 000. You can change this in two ways:
1899
1900 (a) When configuring PCRE before making, you can use --with-match-limit=n
1901 to set a default value for the compiled library.
1902
1903 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1904 a different value is set. See 45 below.
1905
1906 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
1907
1908 43. Added a new function pcre_config(int, void *) to enable run-time extraction
1909 of things that can be changed at compile time. The first argument specifies
1910 what is wanted and the second points to where the information is to be placed.
1911 The current list of available information is:
1912
1913 PCRE_CONFIG_UTF8
1914
1915 The output is an integer that is set to one if UTF-8 support is available;
1916 otherwise it is set to zero.
1917
1918 PCRE_CONFIG_NEWLINE
1919
1920 The output is an integer that it set to the value of the code that is used for
1921 newline. It is either LF (10) or CR (13).
1922
1923 PCRE_CONFIG_LINK_SIZE
1924
1925 The output is an integer that contains the number of bytes used for internal
1926 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
1927
1928 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
1929
1930 The output is an integer that contains the threshold above which the POSIX
1931 interface uses malloc() for output vectors. See item 31 above.
1932
1933 PCRE_CONFIG_MATCH_LIMIT
1934
1935 The output is an unsigned integer that contains the default limit of the number
1936 of match() calls in a pcre_exec() execution. See 42 above.
1937
1938 44. pcretest has been upgraded by the addition of the -C option. This causes it
1939 to extract all the available output from the new pcre_config() function, and to
1940 output it. The program then exits immediately.
1941
1942 45. A need has arisen to pass over additional data with calls to pcre_exec() in
1943 order to support additional features. One way would have been to define
1944 pcre_exec2() (for example) with extra arguments, but this would not have been
1945 extensible, and would also have required all calls to the original function to
1946 be mapped to the new one. Instead, I have chosen to extend the mechanism that
1947 is used for passing in "extra" data from pcre_study().
1948
1949 The pcre_extra structure is now exposed and defined in pcre.h. It currently
1950 contains the following fields:
1951
1952 flags a bitmap indicating which of the following fields are set
1953 study_data opaque data from pcre_study()
1954 match_limit a way of specifying a limit on match() calls for a specific
1955 call to pcre_exec()
1956 callout_data data for callouts (see 49 below)
1957
1958 The flag bits are also defined in pcre.h, and are
1959
1960 PCRE_EXTRA_STUDY_DATA
1961 PCRE_EXTRA_MATCH_LIMIT
1962 PCRE_EXTRA_CALLOUT_DATA
1963
1964 The pcre_study() function now returns one of these new pcre_extra blocks, with
1965 the actual study data pointed to by the study_data field, and the
1966 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
1967 before. That is, this change is entirely upwards-compatible and requires no
1968 change to existing code.
1969
1970 If you want to pass in additional data to pcre_exec(), you can either place it
1971 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
1972 block.
1973
1974 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
1975 data string contains the escape sequence \M, pcretest calls pcre_exec() several
1976 times with different match limits, until it finds the minimum value needed for
1977 pcre_exec() to complete. The value is then output. This can be instructive; for
1978 most simple matches the number is quite small, but for pathological cases it
1979 gets very large very quickly.
1980
1981 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
1982 returns the size of the data block pointed to by the study_data field in a
1983 pcre_extra block, that is, the value that was passed as the argument to
1984 pcre_malloc() when PCRE was getting memory in which to place the information
1985 created by pcre_study(). The fourth argument should point to a size_t variable.
1986 pcretest has been extended so that this information is shown after a successful
1987 pcre_study() call when information about the compiled regex is being displayed.
1988
1989 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
1990 because what follows is always an absolute path. (Later: it turns out that this
1991 is more than cosmetic for MinGW, because it doesn't like empty path
1992 components.)
1993
1994 49. Some changes have been made to the callout feature (see 28 above):
1995
1996 (i) A callout function now has three choices for what it returns:
1997
1998 0 => success, carry on matching
1999 > 0 => failure at this point, but backtrack if possible
2000 < 0 => serious error, return this value from pcre_exec()
2001
2002 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2003 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2004 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2005 use by callout functions. It will never be used by PCRE itself.
2006
2007 (ii) The pcre_extra structure (see 45 above) has a void * field called
2008 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2009 pcre_callout_block structure has a field of the same name. The contents of
2010 the field passed in the pcre_extra structure are passed to the callout
2011 function in the corresponding field in the callout block. This makes it
2012 easier to use the same callout-containing regex from multiple threads. For
2013 testing, the pcretest program has a new data escape
2014
2015 \C*n pass the number n (may be negative) as callout_data
2016
2017 If the callout function in pcretest receives a non-zero value as
2018 callout_data, it returns that value.
2019
2020 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2021 there were some redundant $(CFLAGS) in commands that are now specified as
2022 $(LINK), which already includes $(CFLAGS).
2023
2024 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2025 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2026 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2027 one-byte characters throughout. Note that case-insensitive matching applies
2028 only to characters whose values are less than 256. PCRE doesn't support the
2029 notion of cases for higher-valued characters.
2030
2031 (i) A character class whose characters are all within 0-255 is handled as
2032 a bit map, and the map is inverted for negative classes. Previously, a
2033 character > 255 always failed to match such a class; however it should
2034 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2035
2036 (ii) A negated character class with a single character < 255 is coded as
2037 "not this character" (OP_NOT). This wasn't working properly when the test
2038 character was multibyte, either singly or repeated.
2039
2040 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2041 mode, for example: \x{100}{2,3}.
2042
2043 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2044 singly or repeated) now correctly test multibyte characters. However,
2045 PCRE doesn't recognize any characters with values greater than 255 as
2046 digits, spaces, or word characters. Such characters always match \D, \S,
2047 and \W, and never match \d, \s, or \w.
2048
2049 (v) Classes may now contain characters and character ranges with values
2050 greater than 255. For example: [ab\x{100}-\x{400}].
2051
2052 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2053 PCRE in UTF-8 mode.
2054
2055 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2056 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2057 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2058 value.)
2059
2060 53. The single man page has become too large. I have therefore split it up into
2061 a number of separate man pages. These also give rise to individual HTML pages;
2062 these are now put in a separate directory, and there is an index.html page that
2063 lists them all. Some hyperlinking between the pages has been installed.
2064
2065 54. Added convenience functions for handling named capturing parentheses.
2066
2067 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2068 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2069 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2070 are faulted.
2071
2072 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2073 calling configure. These values are used when compiling the dftables.c program
2074 which is run to generate the source of the default character tables. They
2075 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2076 you will need to set these values.
2077
2078 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2079
2080
2081 Version 3.9 02-Jan-02
2082 ---------------------
2083
2084 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2085
2086 2. If --disable-static was given, the building process failed when trying to
2087 build pcretest and pcregrep. (For some reason it was using libtool to compile
2088 them, which is not right, as they aren't part of the library.)
2089
2090
2091 Version 3.8 18-Dec-01
2092 ---------------------
2093
2094 1. The experimental UTF-8 code was completely screwed up. It was packing the
2095 bytes in the wrong order. How dumb can you get?
2096
2097
2098 Version 3.7 29-Oct-01
2099 ---------------------
2100
2101 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2102 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2103 this didn't happen under Solaris 8, where I normally test things.
2104
2105 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2106 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2107 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2108 this fix an hour or so after the initial 3.7 release.)
2109
2110
2111 Version 3.6 23-Oct-01
2112 ---------------------
2113
2114 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2115 offsets passed as NULL with zero offset count.
2116
2117 2. The config.guess and config.sub files had not been updated when I moved to
2118 the latest autoconf.
2119
2120
2121 Version 3.5 15-Aug-01
2122 ---------------------
2123
2124 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2125 had been forgotten.
2126
2127 2. By using declared but undefined structures, we can avoid using "void"
2128 definitions in pcre.h while keeping the internal definitions of the structures
2129 private.
2130
2131 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2132 user point of view, this means that both static and shared libraries are built
2133 by default, but this can be individually controlled. More of the work of
2134 handling this static/shared cases is now inside libtool instead of PCRE's make
2135 file.
2136
2137 4. The pcretest utility is now installed along with pcregrep because it is
2138 useful for users (to test regexs) and by doing this, it automatically gets
2139 relinked by libtool. The documentation has been turned into a man page, so
2140 there are now .1, .txt, and .html versions in /doc.
2141
2142 5. Upgrades to pcregrep:
2143 (i) Added long-form option names like gnu grep.
2144 (ii) Added --help to list all options with an explanatory phrase.
2145 (iii) Added -r, --recursive to recurse into sub-directories.
2146 (iv) Added -f, --file to read patterns from a file.
2147
2148 6. pcre_exec() was referring to its "code" argument before testing that
2149 argument for NULL (and giving an error if it was NULL).
2150
2151 7. Upgraded Makefile.in to allow for compiling in a different directory from
2152 the source directory.
2153
2154 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2155 options bits, the pointer it was passed was to an int instead of to an unsigned
2156 long int. This mattered only on 64-bit systems.
2157
2158 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2159 generated) instead of pcre.in, which it its source. Also made the same change
2160 in several of the .c files.
2161
2162 10. A new release of gcc defines printf() as a macro, which broke pcretest
2163 because it had an ifdef in the middle of a string argument for printf(). Fixed
2164 by using separate calls to printf().
2165
2166 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2167 script, to force use of CR or LF instead of \n in the source. On non-Unix
2168 systems, the value can be set in config.h.
2169
2170 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2171 absolute limit. Changed the text of the error message to make this clear, and
2172 likewise updated the man page.
2173
2174 13. The limit of 99 on the number of capturing subpatterns has been removed.
2175 The new limit is 65535, which I hope will not be a "real" limit.
2176
2177
2178 Version 3.4 22-Aug-00
2179 ---------------------
2180
2181 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2182
2183 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2184
2185
2186 Version 3.3 01-Aug-00
2187 ---------------------
2188
2189 1. If an octal character was given, but the value was greater than \377, it
2190 was not getting masked to the least significant bits, as documented. This could
2191 lead to crashes in some systems.
2192
2193 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2194 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2195
2196 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2197 These just pass their arguments on to (pcre_free)(), but they are provided
2198 because some uses of PCRE bind it to non-C systems that can call its functions,
2199 but cannot call free() or pcre_free() directly.
2200
2201 4. Add "make test" as a synonym for "make check". Corrected some comments in
2202 the Makefile.
2203
2204 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2205 Makefile.
2206
2207 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2208 command called pgrep for grepping around the active processes.
2209
2210 7. Added the beginnings of support for UTF-8 character strings.
2211
2212 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2213 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2214 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2215 out for the ar command.)
2216
2217
2218 Version 3.2 12-May-00
2219 ---------------------
2220
2221 This is purely a bug fixing release.
2222
2223 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2224 of ZA. This was just one example of several cases that could provoke this bug,
2225 which was introduced by change 9 of version 2.00. The code for breaking
2226 infinite loops after an iteration that matches an empty string was't working
2227 correctly.
2228
2229 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2230 when matched against abbab (for example). After matching an empty string, it
2231 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2232 caused it to match further down the string than it should.
2233
2234 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2235 was there because it doesn't seem to be needed, and it causes trouble on some
2236 systems, as it is not a Standard C header. It has been removed.
2237
2238 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2239 were reported on the Macintosh. The changes were from
2240
2241 while ((c = *(++ptr)) != 0 && c != '\n');
2242 to
2243 while ((c = *(++ptr)) != 0 && c != '\n') ;
2244
2245 Totally extraordinary, but if that's what it takes...
2246
2247 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2248 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2249 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2250 assumes the way PCRE uses memmove() (always moving upwards).
2251
2252 6. PCRE is being used in one environment where strchr() is not available. There
2253 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2254 faster code anyway.
2255
2256
2257 Version 3.1 09-Feb-00
2258 ---------------------
2259
2260 The only change in this release is the fixing of some bugs in Makefile.in for
2261 the "install" target:
2262
2263 (1) It was failing to install pcreposix.h.
2264
2265 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2266
2267
2268 Version 3.0 01-Feb-00
2269 ---------------------
2270
2271 1. Add support for the /+ modifier to perltest (to output $` like it does in
2272 pcretest).
2273
2274 2. Add support for the /g modifier to perltest.
2275
2276 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2277 matches null strings.
2278
2279 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2280 pattern. Perl treats empty patterns specially - it reuses the most recent
2281 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2282 effect.
2283
2284 5. The POSIX interface was broken in that it was just handing over the POSIX
2285 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2286 required a bigger vector, with some working space on the end. This means that
2287 the POSIX wrapper now has to get and free some memory, and copy the results.
2288
2289 6. Added some simple autoconf support, placing the test data and the
2290 documentation in separate directories, re-organizing some of the
2291 information files, and making it build pcre-config (a GNU standard). Also added
2292 libtool support for building PCRE as a shared library, which is now the
2293 default.
2294
2295 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2296 09 are not valid octal constants. Single digits will be used for minor values
2297 less than 10.
2298
2299 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2300 existing programs that set these in the POSIX interface can use PCRE without
2301 modification.
2302
2303 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2304 return all that pcre_info() returns, plus additional data. The pcre_info()
2305 function is retained for compatibility, but is considered to be obsolete.
2306
2307 10. Added experimental recursion feature (?R) to handle one common case that
2308 Perl 5.6 will be able to do with (?p{...}).
2309
2310 11. Added support for POSIX character classes like [:alpha:], which Perl is
2311 adopting.
2312
2313
2314 Version 2.08 31-Aug-99
2315 ----------------------
2316
2317 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2318 trying to match at the startoffset position, but instead was moving forward to
2319 the next newline as if a previous match had failed.
2320
2321 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2322 and could get into a loop if a null string was matched other than at the start
2323 of the subject.
2324
2325 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2326 be distinguished at compile time, and for completeness also added PCRE_DATE.
2327
2328 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2329 in GnuWin32 environments.
2330
2331
2332 Version 2.07 29-Jul-99
2333 ----------------------
2334
2335 1. The documentation is now supplied in plain text form and HTML as well as in
2336 the form of man page sources.
2337
2338 2. C++ compilers don't like assigning (void *) values to other pointer types.
2339 In particular this affects malloc(). Although there is no problem in Standard
2340 C, I've put in casts to keep C++ compilers happy.
2341
2342 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2343 should be (const char *).
2344
2345 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2346 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2347 However, I haven't made this a standard facility. The documentation doesn't
2348 mention it, and the Makefile doesn't support it.
2349
2350 5. The Makefile now contains an "install" target, with editable destinations at
2351 the top of the file. The pcretest program is not installed.
2352
2353 6. pgrep -V now gives the PCRE version number and date.
2354
2355 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2356 causing the entire string to be ignored, instead of just the last character.
2357
2358 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2359 non-matching string, it can take a very, very long time, even for strings of
2360 quite modest length, because of the nested recursion. PCRE now does better in
2361 some of these cases. It does this by remembering the last required literal
2362 character in the pattern, and pre-searching the subject to ensure it is present
2363 before running the real match. In other words, it applies a heuristic to detect
2364 some types of certain failure quickly, and in the above example, if presented
2365 with a string that has no trailing " it gives "no match" very quickly.
2366
2367 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2368 other alternatives are tried instead.
2369
2370
2371 Version 2.06 09-Jun-99
2372 ----------------------
2373
2374 1. Change pcretest's output for amount of store used to show just the code
2375 space, because the remainder (the data block) varies in size between 32-bit and
2376 64-bit systems.
2377
2378 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2379 start matching at. This allows lookbehinds to work when searching for multiple
2380 occurrences in a string.
2381
2382 3. Added additional options to pcretest for testing multiple occurrences:
2383
2384 /+ outputs the rest of the string that follows a match
2385 /g loops for multiple occurrences, using the new startoffset argument
2386 /G loops for multiple occurrences by passing an incremented pointer
2387
2388 4. PCRE wasn't doing the "first character" optimization for patterns starting
2389 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2390 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2391 the letter 'x'. On long subject strings, this gives a significant speed-up.
2392
2393
2394 Version 2.05 21-Apr-99
2395 ----------------------
2396
2397 1. Changed the type of magic_number from int to long int so that it works
2398 properly on 16-bit systems.
2399
2400 2. Fixed a bug which caused patterns starting with .* not to work correctly
2401 when the subject string contained newline characters. PCRE was assuming
2402 anchoring for such patterns in all cases, which is not correct because .* will
2403 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2404 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2405 must be retried after every newline in the subject.
2406
2407
2408 Version 2.04 18-Feb-99
2409 ----------------------
2410
2411 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2412 computation of the store needed to hold the pattern was incorrect (too large).
2413 If such patterns were nested a few deep, this could multiply and become a real
2414 problem.
2415
2416 2. Added /M option to pcretest to show the memory requirement of a specific
2417 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2418
2419 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2420 compiled in such a way that the backtracking after subsequent failure was
2421 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2422 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2423
2424
2425 Version 2.03 02-Feb-99
2426 ----------------------
2427
2428 1. Fixed typo and small mistake in man page.
2429
2430 2. Added 4th condition (GPL supersedes if conflict) and created separate
2431 LICENCE file containing the conditions.
2432
2433 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2434 Perl, that is the internal \ allows the delimiter to be included in the
2435 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2436 the final delimiter, add \ to the end of the pattern (to test the error).
2437
2438 4. Added the convenience functions for extracting substrings after a successful
2439 match. Updated pcretest to make it able to test these functions.
2440
2441
2442 Version 2.02 14-Jan-99
2443 ----------------------
2444
2445 1. Initialized the working variables associated with each extraction so that
2446 their saving and restoring doesn't refer to uninitialized store.
2447
2448 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2449 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2450 fix the problem.
2451
2452 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2453 calls, and wasn't printing the correct value for compiling calls. Increased the
2454 default value of LOOPREPEAT, and the number of significant figures in the
2455 times.
2456
2457 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2458
2459 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2460 a building problem on Windows NT with a FAT file system.
2461
2462
2463 Version 2.01 21-Oct-98
2464 ----------------------
2465
2466 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2467 to character tables built by pcre_maketables() in the current locale. If NULL
2468 is passed, the default tables are used.
2469
2470
2471 Version 2.00 24-Sep-98
2472 ----------------------
2473
2474 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2475 it any more.
2476
2477 2. Allow quantification of (?>) groups, and make it work correctly.
2478
2479 3. The first character computation wasn't working for (?>) groups.
2480
2481 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2482 end of the subject) and add 5.005's \z, which really does match only at the
2483 very end of the subject.
2484
2485 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2486
2487 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2488 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2489 localized options. All options to pcre_study() were also removed.
2490
2491 7. Add other new features from 5.005:
2492
2493 $(?<= positive lookbehind
2494 $(?<! negative lookbehind
2495 (?imsx-imsx) added the unsetting capability
2496 such a setting is global if at outer level; local otherwise
2497 (?imsx-imsx:) non-capturing groups with option setting
2498 (?(cond)re|re) conditional pattern matching
2499
2500 A backreference to itself in a repeated group matches the previous
2501 captured string.
2502
2503 8. General tidying up of studying (both automatic and via "study")
2504 consequential on the addition of new assertions.
2505
2506 9. As in 5.005, unlimited repeated groups that could match an empty substring
2507 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2508 runtime if any iteration does actually match an empty substring.
2509
2510 10. Include the RunTest script in the distribution.
2511
2512 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2513 discrepancies, some of which were old and were also with respect to 5.004. They
2514 have now been fixed.
2515
2516
2517 Version 1.09 28-Apr-98
2518 ----------------------
2519
2520 1. A negated single character class followed by a quantifier with a minimum
2521 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2522 program crashes, or just wrong answers. This did not apply to negated classes
2523 containing more than one character, or to minima other than one.
2524
2525
2526 Version 1.08 27-Mar-98
2527 ----------------------
2528
2529 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2530
2531 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2532 latter must appear before anything that relies on it in the pattern.
2533
2534
2535 Version 1.07 16-Feb-98
2536 ----------------------
2537
2538 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2539 repeat of a potentially empty string).
2540
2541
2542 Version 1.06 23-Jan-98
2543 ----------------------
2544
2545 1. Added Markus Oberhumer's little patches for C++.
2546
2547 2. Literal strings longer than 255 characters were broken.
2548
2549
2550 Version 1.05 23-Dec-97
2551 ----------------------
2552
2553 1. Negated character classes containing more than one character were failing if
2554 PCRE_CASELESS was set at run time.
2555
2556
2557 Version 1.04 19-Dec-97
2558 ----------------------
2559
2560 1. Corrected the man page, where some "const" qualifiers had been omitted.
2561
2562 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2563 input syntax.
2564
2565 3. Fixed memory leak which occurred when a regex with back references was
2566 matched with an offsets vector that wasn't big enough. The temporary memory
2567 that is used in this case wasn't being freed if the match failed.
2568
2569 4. Tidied pcretest to ensure it frees memory that it gets.
2570
2571 5. Temporary memory was being obtained in the case where the passed offsets
2572 vector was exactly big enough.
2573
2574 6. Corrected definition of offsetof() from change 5 below.
2575
2576 7. I had screwed up change 6 below and broken the rules for the use of
2577 setjmp(). Now fixed.
2578
2579
2580 Version 1.03 18-Dec-97
2581 ----------------------
2582
2583 1. A erroneous regex with a missing opening parenthesis was correctly
2584 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2585 on some systems.
2586
2587 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2588 it was reported that one broken compiler failed on the former because "code" is
2589 also an independent variable.
2590
2591 3. The erroneous regex a[]b caused an array overrun reference.
2592
2593 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2594 fail on data ending with that character. (It was going on too far, and checking
2595 the next character, typically a binary zero.) This was specific to the
2596 optimized code for single-character negative classes.
2597
2598 5. Added a contributed patch from the TIN world which does the following:
2599
2600 + Add an undef for memmove, in case the the system defines a macro for it.
2601
2602 + Add a definition of offsetof(), in case there isn't one. (I don't know
2603 the reason behind this - offsetof() is part of the ANSI standard - but
2604 it does no harm).
2605
2606 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2607 most of the places where whitespace preceded '#'. I have given up and
2608 allowed the remaining 2 cases to be at the margin.
2609
2610 + Rename some variables in pcre to eliminate shadowing. This seems very
2611 pedantic, but does no harm, of course.
2612
2613 6. Moved the call to setjmp() into its own function, to get rid of warnings
2614 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2615
2616 7. Constructs such as \d{8,} were compiling into the equivalent of
2617 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2618 outcome, but in this particular case used more store than had been allocated,
2619 which caused the bug to be discovered because it threw up an internal error.
2620
2621 8. The debugging code in both pcre and pcretest for outputting the compiled
2622 form of a regex was going wrong in the case of back references followed by
2623 curly-bracketed repeats.
2624
2625
2626 Version 1.02 12-Dec-97
2627 ----------------------
2628
2629 1. Typos in pcre.3 and comments in the source fixed.
2630
2631 2. Applied a contributed patch to get rid of places where it used to remove
2632 'const' from variables, and fixed some signed/unsigned and uninitialized
2633 variable warnings.
2634
2635 3. Added the "runtest" target to Makefile.
2636
2637 4. Set default compiler flag to -O2 rather than just -O.
2638
2639
2640 Version 1.01 19-Nov-97
2641 ----------------------
2642
2643 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2644 like /([ab]*)*/, that is, for classes with more than one character in them.
2645
2646 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2647 as /((?>a*))*/ (a PCRE_EXTRA facility).
2648
2649
2650 Version 1.00 18-Nov-97
2651 ----------------------
2652
2653 1. Added compile-time macros to support systems such as SunOS4 which don't have
2654 memmove() or strerror() but have other things that can be used instead.
2655
2656 2. Arranged that "make clean" removes the executables.
2657
2658
2659 Version 0.99 27-Oct-97
2660 ----------------------
2661
2662 1. Fixed bug in code for optimizing classes with only one character. It was
2663 initializing a 32-byte map regardless, which could cause it to run off the end
2664 of the memory it had got.
2665
2666 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2667
2668
2669 Version 0.98 22-Oct-97
2670 ----------------------
2671
2672 1. Fixed bug in code for handling temporary memory usage when there are more
2673 back references than supplied space in the ovector. This could cause segfaults.
2674
2675
2676 Version 0.97 21-Oct-97
2677 ----------------------
2678
2679 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2680
2681 2. Optimized negated single characters not to use a bit map.
2682
2683 3. Brought error texts together as macro definitions; clarified some of them;
2684 fixed one that was wrong - it said "range out of order" when it meant "invalid
2685 escape sequence".
2686
2687 4. Changed some char * arguments to const char *.
2688
2689 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2690
2691 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2692 pcretest.
2693
2694
2695 Version 0.96 16-Oct-97
2696 ----------------------
2697
2698 1. Added a simple "pgrep" utility to the distribution.
2699
2700 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2701 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2702 where "ddd" means "one or more decimal digits".
2703
2704 3. Fixed serious bug. If a pattern had a back reference, but the call to
2705 pcre_exec() didn't supply a large enough ovector to record the related
2706 identifying subpattern, the match always failed. PCRE now remembers the number
2707 of the largest back reference, and gets some temporary memory in which to save
2708 the offsets during matching if necessary, in order to ensure that
2709 backreferences always work.
2710
2711 4. Increased the compatibility with Perl in a number of ways:
2712
2713 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2714 to request this handling. The option can be set at compile or exec time.
2715
2716 (b) $ matches before a terminating newline by default; an option
2717 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2718 mode). The option can be set at compile or exec time.
2719
2720 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2721 the same as Perl's. If the decimal number it represents is less than 10
2722 or there aren't that many previous left capturing parentheses, an octal
2723 escape is read. Inside a character class, it's always an octal escape,
2724 even if it is a single digit.
2725
2726 (d) An escaped but undefined alphabetic character is taken as a literal,
2727 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2728 escapes.
2729
2730 (e) {0} is now permitted. (The previous item is removed from the compiled
2731 pattern).
2732
2733 5. Changed all the names of code files so that the basic parts are no longer
2734 than 10 characters, and abolished the teeny "globals.c" file.
2735
2736 6. Changed the handling of character classes; they are now done with a 32-byte
2737 bit map always.
2738
2739 7. Added the -d and /D options to pcretest to make it possible to look at the
2740 internals of compilation without having to recompile pcre.
2741
2742
2743 Version 0.95 23-Sep-97
2744 ----------------------
2745
2746 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2747 \x20 at the start of a run of normal characters. These were being treated as
2748 real characters, instead of the source characters being re-checked.
2749
2750
2751 Version 0.94 18-Sep-97
2752 ----------------------
2753
2754 1. The functions are now thread-safe, with the caveat that the global variables
2755 containing pointers to malloc() and free() or alternative functions are the
2756 same for all threads.
2757
2758 2. Get pcre_study() to generate a bitmap of initial characters for non-
2759 anchored patterns when this is possible, and use it if passed to pcre_exec().
2760
2761
2762 Version 0.93 15-Sep-97
2763 ----------------------
2764
2765 1. /(b)|(:+)/ was computing an incorrect first character.
2766
2767 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2768 but not actually doing anything yet.
2769
2770 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2771 as Perl does (e.g. [-az] or [az-]).
2772
2773 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2774 all possible positions.
2775
2776 5. Split up into different modules to avoid including unneeded functions in a
2777 compiled binary. However, compile and exec are still in one module. The "study"
2778 function is split off.
2779
2780 6. The character tables are now in a separate module whose source is generated
2781 by an auxiliary program - but can then be edited by hand if required. There are
2782 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2783 toupper() in the code.
2784
2785 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2786 make them global. Abolish the function for setting them, as the caller can now
2787 set them directly.
2788
2789
2790 Version 0.92 11-Sep-97
2791 ----------------------
2792
2793 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2794 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2795
2796 2. Caseless matching was not working in character classes if the characters in
2797 the pattern were in upper case.
2798
2799 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2800
2801 4. Make PCRE_ANCHORED public and accept as a compile option.
2802
2803 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
2804 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
2805 pass them.
2806
2807 6. Give an error if bad option bits passed at compile or run time.
2808
2809 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
2810 pcretest to cause it to pass that flag.
2811
2812 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
2813 options, and the first character, if set.
2814
2815 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
2816
2817
2818 Version 0.91 10-Sep-97
2819 ----------------------
2820
2821 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
2822 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
2823
2824 2. PCRE was looping on encountering an indefinitely repeated back reference to
2825 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
2826 Perl does - treats the match as successful.
2827
2828 ****

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