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Revision 218 - (show annotations) (download)
Thu Aug 16 10:13:23 2007 UTC (7 years ago) by ph10
File size: 137184 byte(s)
Fix several compile bugs involving repeated \p or \P items.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.3 09-Aug-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" and "%I64u" instead of "%llu" for
33 long printing in the pcrecpp 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 9. There were some crude static tests to avoid integer overflow when computing
57 the size of patterns that contain repeated groups with explicit upper
58 limits. As the maximum quantifier is 65535, the maximum group length was
59 set at 30,000 so that the product of these two numbers did not overflow a
60 32-bit integer. However, it turns out that people want to use groups that
61 are longer than 30,000 bytes (though not repeat them that many times).
62 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
63 made it possible to implement the integer overflow checks in a much more
64 dynamic way, which I have now done. The artificial limitation on group
65 length has been removed - we now have only the limit on the total length of
66 the compiled pattern, which depends on the LINK_SIZE setting.
67
68 10. Fixed a bug in the documentation for get/copy named substring when
69 duplicate names are permitted. If none of the named substrings are set, the
70 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
71 empty string.
72
73 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
74 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
75 because the ] is interpreted as the first data character and the
76 terminating ] is not found. PCRE has been made compatible with Perl in this
77 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
78 cause memory overwriting.
79
80 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
81 string has been matched (to stop an infinite loop). It was not recognizing
82 a conditional subpattern that could match an empty string if that
83 subpattern was within another subpattern. For example, it looped when
84 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
85 condition was not nested. This bug has been fixed.
86
87 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
88 past the start of the subject in the presence of bytes with the top bit
89 set, for example "\x8aBCD".
90
91 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
92 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
93
94 14. Optimized (?!) to (*FAIL).
95
96 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
97 This restricts code points to be within the range 0 to 0x10FFFF, excluding
98 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
99 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
100 does: it's just the validity check that is more restrictive.
101
102 16. Inserted checks for integer overflows during escape sequence (backslash)
103 processing, and also fixed erroneous offset values for syntax errors during
104 backslash processing.
105
106 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
107 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
108
109 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
110 caused an overrun.
111
112 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
113 something other than just ASCII characters) inside a group that had an
114 unlimited repeat caused a loop at compile time (while checking to see
115 whether the group could match an empty string).
116
117 20. Debugging a pattern containing \p or \P could cause a crash. For example,
118 [\P{Any}] did so. (Error in the code for printing property names.)
119
120 21. An orphan \E inside a character class could cause a crash.
121
122 22. A repeated capturing bracket such as (A)? could cause a wild memory
123 reference during compilation.
124
125 23. There are several functions in pcre_compile() that scan along a compiled
126 expression for various reasons (e.g. to see if it's fixed length for look
127 behind). There were bugs in these functions when a repeated \p or \P was
128 present in the pattern. These operators have additional parameters compared
129 with \d, etc, and these were not being taken into account when moving along
130 the compiled data. Specifically:
131
132 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
133 length.
134
135 (b) An item such as \pL+ within a repeated group could cause crashes or
136 loops.
137
138 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
139 "reference to non-existent subpattern" error.
140
141
142 Version 7.2 19-Jun-07
143 ---------------------
144
145 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
146 which is apparently normally available under Windows.
147
148 2. Re-jig the pcregrep tests with different newline settings in an attempt
149 to make them independent of the local environment's newline setting.
150
151 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
152
153 4. Some of the "internals" tests were previously cut out when the link size
154 was not 2, because the output contained actual offsets. The recent new
155 "Z" feature of pcretest means that these can be cut out, making the tests
156 usable with all link sizes.
157
158 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
159 stack recursion. This gives a massive performance boost under BSD, but just
160 a small improvement under Linux. However, it saves one field in the frame
161 in all cases.
162
163 6. Added more features from the forthcoming Perl 5.10:
164
165 (a) (?-n) (where n is a string of digits) is a relative subroutine or
166 recursion call. It refers to the nth most recently opened parentheses.
167
168 (b) (?+n) is also a relative subroutine call; it refers to the nth next
169 to be opened parentheses.
170
171 (c) Conditions that refer to capturing parentheses can be specified
172 relatively, for example, (?(-2)... or (?(+3)...
173
174 (d) \K resets the start of the current match so that everything before
175 is not part of it.
176
177 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
178
179 (f) \g{name} is another synonym - part of Perl 5.10's unification of
180 reference syntax.
181
182 (g) (?| introduces a group in which the numbering of parentheses in each
183 alternative starts with the same number.
184
185 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
186
187 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
188 PCRE_INFO_JCHANGED.
189
190 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
191 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
192 for detecting groups that can match an empty string.
193
194 9. A pattern with a very large number of alternatives (more than several
195 hundred) was running out of internal workspace during the pre-compile
196 phase, where pcre_compile() figures out how much memory will be needed. A
197 bit of new cunning has reduced the workspace needed for groups with
198 alternatives. The 1000-alternative test pattern now uses 12 bytes of
199 workspace instead of running out of the 4096 that are available.
200
201 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
202
203 11. Applied patch from Google to remove an optimization that didn't quite work.
204 The report of the bug said:
205
206 pcrecpp::RE("a*").FullMatch("aaa") matches, while
207 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
208 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
209
210 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
211 it matched the wrong number of bytes.
212
213
214 Version 7.1 24-Apr-07
215 ---------------------
216
217 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
218 that is more "standard", making use of automake and other Autotools. There
219 is some re-arrangement of the files and adjustment of comments consequent
220 on this.
221
222 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
223 for recursive directory scanning broke on some systems because the files
224 are not scanned in any specific order and on different systems the order
225 was different. A call to "sort" has been inserted into RunGrepTest for the
226 approprate test as a short-term fix. In the longer term there may be an
227 alternative.
228
229 3. I had an email from Eric Raymond about problems translating some of PCRE's
230 man pages to HTML (despite the fact that I distribute HTML pages, some
231 people do their own conversions for various reasons). The problems
232 concerned the use of low-level troff macros .br and .in. I have therefore
233 removed all such uses from the man pages (some were redundant, some could
234 be replaced by .nf/.fi pairs). The 132html script that I use to generate
235 HTML has been updated to handle .nf/.fi and to complain if it encounters
236 .br or .in.
237
238 4. Updated comments in configure.ac that get placed in config.h.in and also
239 arranged for config.h to be included in the distribution, with the name
240 config.h.generic, for the benefit of those who have to compile without
241 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
242
243 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
244 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
245 makevp.bat for the current PCRE, using the additional files
246 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
247
248 6. A Windows user reported a minor discrepancy with test 2, which turned out
249 to be caused by a trailing space on an input line that had got lost in his
250 copy. The trailing space was an accident, so I've just removed it.
251
252 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
253 that is needed.
254
255 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
256 as "const" (a) because they are and (b) because it helps the PHP
257 maintainers who have recently made a script to detect big data structures
258 in the php code that should be moved to the .rodata section. I remembered
259 to update Builducptable as well, so it won't revert if ucptable.h is ever
260 re-created.
261
262 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
263 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
264 order to be able to cut out the UTF-8 tables in the latter when UTF-8
265 support is not required. This saves 1.5-2K of code, which is important in
266 some applications.
267
268 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
269 so as not to refer to the tables, even though these functions will never be
270 called when UTF-8 support is disabled. Otherwise there are problems with a
271 shared library.
272
273 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
274
275 (a) It was defining its arguments as char * instead of void *.
276
277 (b) It was assuming that all moves were upwards in memory; this was true
278 a long time ago when I wrote it, but is no longer the case.
279
280 The emulated memove() is provided for those environments that have neither
281 memmove() nor bcopy(). I didn't think anyone used it these days, but that
282 is clearly not the case, as these two bugs were recently reported.
283
284 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
285 and Detrail to create the HTML documentation, the .txt form of the man
286 pages, and it removes trailing spaces from listed files. It also creates
287 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
288 case, it wraps all the #defines with #ifndefs. This script should be run
289 before "make dist".
290
291 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
292 with Unicode property support.
293
294 (a) For a maximizing quantifier, if the two different cases of the
295 character were of different lengths in their UTF-8 codings (there are
296 some cases like this - I found 11), and the matching function had to
297 back up over a mixture of the two cases, it incorrectly assumed they
298 were both the same length.
299
300 (b) When PCRE was configured to use the heap rather than the stack for
301 recursion during matching, it was not correctly preserving the data for
302 the other case of a UTF-8 character when checking ahead for a match
303 while processing a minimizing repeat. If the check also involved
304 matching a wide character, but failed, corruption could cause an
305 erroneous result when trying to check for a repeat of the original
306 character.
307
308 13. Some tidying changes to the testing mechanism:
309
310 (a) The RunTest script now detects the internal link size and whether there
311 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
312 values substituted by "configure". (The RunGrepTest script already did
313 this for UTF-8.) The configure.ac script no longer substitutes the
314 relevant variables.
315
316 (b) The debugging options /B and /D in pcretest show the compiled bytecode
317 with length and offset values. This means that the output is different
318 for different internal link sizes. Test 2 is skipped for link sizes
319 other than 2 because of this, bypassing the problem. Unfortunately,
320 there was also a test in test 3 (the locale tests) that used /B and
321 failed for link sizes other than 2. Rather than cut the whole test out,
322 I have added a new /Z option to pcretest that replaces the length and
323 offset values with spaces. This is now used to make test 3 independent
324 of link size. (Test 2 will be tidied up later.)
325
326 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
327 segmentation fault instead of returning the appropriate error message.
328
329 15. In multiline mode when the newline sequence was set to "any", the pattern
330 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
331 This doesn't seem right; it now treats the CRLF combination as the line
332 ending, and so does not match in that case. It's only a pattern such as ^$
333 that would hit this one: something like ^ABC$ would have failed after \r
334 and then tried again after \r\n.
335
336 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
337 in an attempt to make files that differ only in their line terminators
338 compare equal. This works on Linux.
339
340 17. Under certain error circumstances pcregrep might try to free random memory
341 as it exited. This is now fixed, thanks to valgrind.
342
343 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
344 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
345 was because its rules for how to advance for /g after matching an empty
346 string at the end of a line did not allow for this case. They now check for
347 it specially.
348
349 20. pcretest is supposed to handle patterns and data of any length, by
350 extending its buffers when necessary. It was getting this wrong when the
351 buffer for a data line had to be extended.
352
353 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
354 CRLF as a newline sequence.
355
356 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
357 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
358 I have nevertheless tidied it up.
359
360 23. Added some casts to kill warnings from HP-UX ia64 compiler.
361
362 24. Added a man page for pcre-config.
363
364
365 Version 7.0 19-Dec-06
366 ---------------------
367
368 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
369 moving to gcc 4.1.1.
370
371 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
372 sys/time.h, which is documented as needed for this function. It doesn't
373 seem to matter on Linux, but it showed up on some releases of OS X.
374
375 3. It seems that there are systems where bytes whose values are greater than
376 127 match isprint() in the "C" locale. The "C" locale should be the
377 default when a C program starts up. In most systems, only ASCII printing
378 characters match isprint(). This difference caused the output from pcretest
379 to vary, making some of the tests fail. I have changed pcretest so that:
380
381 (a) When it is outputting text in the compiled version of a pattern, bytes
382 other than 32-126 are always shown as hex escapes.
383
384 (b) When it is outputting text that is a matched part of a subject string,
385 it does the same, unless a different locale has been set for the match
386 (using the /L modifier). In this case, it uses isprint() to decide.
387
388 4. Fixed a major bug that caused incorrect computation of the amount of memory
389 required for a compiled pattern when options that changed within the
390 pattern affected the logic of the preliminary scan that determines the
391 length. The relevant options are -x, and -i in UTF-8 mode. The result was
392 that the computed length was too small. The symptoms of this bug were
393 either the PCRE error "internal error: code overflow" from pcre_compile(),
394 or a glibc crash with a message such as "pcretest: free(): invalid next
395 size (fast)". Examples of patterns that provoked this bug (shown in
396 pcretest format) are:
397
398 /(?-x: )/x
399 /(?x)(?-x: \s*#\s*)/
400 /((?i)[\x{c0}])/8
401 /(?i:[\x{c0}])/8
402
403 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
404 is now done differently.
405
406 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
407 wrapper classes; (b) implement a new function in the C++ scanner that is
408 more efficient than the old way of doing things because it avoids levels of
409 recursion in the regex matching; (c) add a paragraph to the documentation
410 for the FullMatch() function.
411
412 6. The escape sequence \n was being treated as whatever was defined as
413 "newline". Not only was this contrary to the documentation, which states
414 that \n is character 10 (hex 0A), but it also went horribly wrong when
415 "newline" was defined as CRLF. This has been fixed.
416
417 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
418 was being set to -1 for the "end of line" case (supposedly a value that no
419 character can have). Though this value is never used (the check for end of
420 line is "zero bytes in current character"), it caused compiler complaints.
421 I've changed it to 0xffffffff.
422
423 8. In pcre_version.c, the version string was being built by a sequence of
424 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
425 string (as it is for production releases) called a macro with an empty
426 argument. The C standard says the result of this is undefined. The gcc
427 compiler treats it as an empty string (which was what was wanted) but it is
428 reported that Visual C gives an error. The source has been hacked around to
429 avoid this problem.
430
431 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
432 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
433 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
434 of them did).
435
436 10. Originally, pcretest opened its input and output without "b"; then I was
437 told that "b" was needed in some environments, so it was added for release
438 5.0 to both the input and output. (It makes no difference on Unix-like
439 systems.) Later I was told that it is wrong for the input on Windows. I've
440 now abstracted the modes into two macros, to make it easier to fiddle with
441 them, and removed "b" from the input mode under Windows.
442
443 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
444
445 12. Added -help and --help to pcretest as an official way of being reminded
446 of the options.
447
448 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
449 and pcrecpp.cc because they annoy compilers at high warning levels.
450
451 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
452
453 15. Fixed an occurrence of == in configure.ac that should have been = (shell
454 scripts are not C programs :-) and which was not noticed because it works
455 on Linux.
456
457 16. pcretest is supposed to handle any length of pattern and data line (as one
458 line or as a continued sequence of lines) by extending its input buffer if
459 necessary. This feature was broken for very long pattern lines, leading to
460 a string of junk being passed to pcre_compile() if the pattern was longer
461 than about 50K.
462
463 17. I have done a major re-factoring of the way pcre_compile() computes the
464 amount of memory needed for a compiled pattern. Previously, there was code
465 that made a preliminary scan of the pattern in order to do this. That was
466 OK when PCRE was new, but as the facilities have expanded, it has become
467 harder and harder to keep it in step with the real compile phase, and there
468 have been a number of bugs (see for example, 4 above). I have now found a
469 cunning way of running the real compile function in a "fake" mode that
470 enables it to compute how much memory it would need, while actually only
471 ever using a few hundred bytes of working memory and without too many
472 tests of the mode. This should make future maintenance and development
473 easier. A side effect of this work is that the limit of 200 on the nesting
474 depth of parentheses has been removed (though this was never a serious
475 limitation, I suspect). However, there is a downside: pcre_compile() now
476 runs more slowly than before (30% or more, depending on the pattern). I
477 hope this isn't a big issue. There is no effect on runtime performance.
478
479 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
480 newline (only possible for the last line of a file) and it was a
481 pattern that set a locale (followed by /Lsomething), pcretest crashed.
482
483 19. Added additional timing features to pcretest. (1) The -tm option now times
484 matching only, not compiling. (2) Both -t and -tm can be followed, as a
485 separate command line item, by a number that specifies the number of
486 repeats to use when timing. The default is 50000; this gives better
487 precision, but takes uncomfortably long for very large patterns.
488
489 20. Extended pcre_study() to be more clever in cases where a branch of a
490 subpattern has no definite first character. For example, (a*|b*)[cd] would
491 previously give no result from pcre_study(). Now it recognizes that the
492 first character must be a, b, c, or d.
493
494 21. There was an incorrect error "recursive call could loop indefinitely" if
495 a subpattern (or the entire pattern) that was being tested for matching an
496 empty string contained only one non-empty item after a nested subpattern.
497 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
498 incorrectly, because the \d was being skipped in the check.
499
500 22. The pcretest program now has a new pattern option /B and a command line
501 option -b, which is equivalent to adding /B to every pattern. This causes
502 it to show the compiled bytecode, without the additional information that
503 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
504 is the same as /B/I).
505
506 23. A new optimization is now able automatically to treat some sequences such
507 as a*b as a*+b. More specifically, if something simple (such as a character
508 or a simple class like \d) has an unlimited quantifier, and is followed by
509 something that cannot possibly match the quantified thing, the quantifier
510 is automatically "possessified".
511
512 24. A recursive reference to a subpattern whose number was greater than 39
513 went wrong under certain circumstances in UTF-8 mode. This bug could also
514 have affected the operation of pcre_study().
515
516 25. Realized that a little bit of performance could be had by replacing
517 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
518
519 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
520
521 27. Possessive quantifiers such as a++ were previously implemented by turning
522 them into atomic groups such as ($>a+). Now they have their own opcodes,
523 which improves performance. This includes the automatically created ones
524 from 23 above.
525
526 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
527 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
528 the first matched character to be a colon. This applied both to named and
529 numbered groups.
530
531 29. The ucpinternal.h header file was missing its idempotency #ifdef.
532
533 30. I was sent a "project" file called libpcre.a.dev which I understand makes
534 building PCRE on Windows easier, so I have included it in the distribution.
535
536 31. There is now a check in pcretest against a ridiculously large number being
537 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
538 loop, the loop is abandoned.
539
540 32. Forward references to subpatterns in conditions such as (?(2)...) where
541 subpattern 2 is defined later cause pcre_compile() to search forwards in
542 the pattern for the relevant set of parentheses. This search went wrong
543 when there were unescaped parentheses in a character class, parentheses
544 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
545
546 33. "Subroutine" calls and backreferences were previously restricted to
547 referencing subpatterns earlier in the regex. This restriction has now
548 been removed.
549
550 34. Added a number of extra features that are going to be in Perl 5.10. On the
551 whole, these are just syntactic alternatives for features that PCRE had
552 previously implemented using the Python syntax or my own invention. The
553 other formats are all retained for compatibility.
554
555 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
556 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
557 also .NET compatible.
558
559 (b) A recursion or subroutine call to a named group can now be defined as
560 (?&name) as well as (?P>name).
561
562 (c) A backreference to a named group can now be defined as \k<name> or
563 \k'name' as well as (?P=name). The new forms, as well as being in Perl
564 5.10, are also .NET compatible.
565
566 (d) A conditional reference to a named group can now use the syntax
567 (?(<name>) or (?('name') as well as (?(name).
568
569 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
570 groups (named and numbered) that are never evaluated inline, but can be
571 called as "subroutines" from elsewhere. In effect, the DEFINE condition
572 is always false. There may be only one alternative in such a group.
573
574 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
575 as the simple (?(R). The condition is true only if the most recent
576 recursion is that of the given number or name. It does not search out
577 through the entire recursion stack.
578
579 (g) The escape \gN or \g{N} has been added, where N is a positive or
580 negative number, specifying an absolute or relative reference.
581
582 35. Tidied to get rid of some further signed/unsigned compiler warnings and
583 some "unreachable code" warnings.
584
585 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
586 things, this adds five new scripts.
587
588 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
589 There were also incompatibilities regarding the handling of \Q..\E inside
590 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
591 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
592
593 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
594 matches an empty string, and forcibly breaks the loop. There were bugs in
595 this code in non-simple cases. For a pattern such as ^(a()*)* matched
596 against aaaa the result was just "a" rather than "aaaa", for example. Two
597 separate and independent bugs (that affected different cases) have been
598 fixed.
599
600 39. Refactored the code to abolish the use of different opcodes for small
601 capturing bracket numbers. This is a tidy that I avoided doing when I
602 removed the limit on the number of capturing brackets for 3.5 back in 2001.
603 The new approach is not only tidier, it makes it possible to reduce the
604 memory needed to fix the previous bug (38).
605
606 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
607 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
608 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
609 mode.
610
611 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
612 report.
613
614 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
615 copy construction and assignment in the C++ wrapper.
616
617 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
618 couple of bugs that could have given wrong results in the "--newline=crlf"
619 case.
620
621 44. Added a number of casts and did some reorganization of signed/unsigned int
622 variables following suggestions from Dair Grant. Also renamed the variable
623 "this" as "item" because it is a C++ keyword.
624
625 45. Arranged for dftables to add
626
627 #include "pcre_internal.h"
628
629 to pcre_chartables.c because without it, gcc 4.x may remove the array
630 definition from the final binary if PCRE is built into a static library and
631 dead code stripping is activated.
632
633 46. For an unanchored pattern, if a match attempt fails at the start of a
634 newline sequence, and the newline setting is CRLF or ANY, and the next two
635 characters are CRLF, advance by two characters instead of one.
636
637
638 Version 6.7 04-Jul-06
639 ---------------------
640
641 1. In order to handle tests when input lines are enormously long, pcretest has
642 been re-factored so that it automatically extends its buffers when
643 necessary. The code is crude, but this _is_ just a test program. The
644 default size has been increased from 32K to 50K.
645
646 2. The code in pcre_study() was using the value of the re argument before
647 testing it for NULL. (Of course, in any sensible call of the function, it
648 won't be NULL.)
649
650 3. The memmove() emulation function in pcre_internal.h, which is used on
651 systems that lack both memmove() and bcopy() - that is, hardly ever -
652 was missing a "static" storage class specifier.
653
654 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
655 containing an extended class (one that cannot be represented by a bitmap
656 because it contains high-valued characters or Unicode property items, e.g.
657 [\pZ]). Almost always one would set UTF-8 mode when processing such a
658 pattern, but PCRE should not loop if you do not (it no longer does).
659 [Detail: two cases were found: (a) a repeated subpattern containing an
660 extended class; (b) a recursive reference to a subpattern that followed a
661 previous extended class. It wasn't skipping over the extended class
662 correctly when UTF-8 mode was not set.]
663
664 5. A negated single-character class was not being recognized as fixed-length
665 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
666 compile error "lookbehind assertion is not fixed length".
667
668 6. The RunPerlTest auxiliary script was showing an unexpected difference
669 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
670 write a Perl script that can interpret lines of an input file either as
671 byte characters or as UTF-8, which is what "perltest" was being required to
672 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
673 can't do is switch easily at run time between having the "use utf8;" pragma
674 or not. In the end, I fudged it by using the RunPerlTest script to insert
675 "use utf8;" explicitly for the UTF-8 tests.
676
677 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
678 the end of the subject string, contrary to the documentation and to what
679 Perl does. This was true of both matching functions. Now it matches only at
680 the start of the subject and immediately after *internal* newlines.
681
682 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
683 a pointer to an int instead of a pointer to an unsigned long int. This
684 caused problems on 64-bit systems.
685
686 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
687 instance of the 'standard' template library not being so standard".
688
689 10. There was no check on the number of named subpatterns nor the maximum
690 length of a subpattern name. The product of these values is used to compute
691 the size of the memory block for a compiled pattern. By supplying a very
692 long subpattern name and a large number of named subpatterns, the size
693 computation could be caused to overflow. This is now prevented by limiting
694 the length of names to 32 characters, and the number of named subpatterns
695 to 10,000.
696
697 11. Subpatterns that are repeated with specific counts have to be replicated in
698 the compiled pattern. The size of memory for this was computed from the
699 length of the subpattern and the repeat count. The latter is limited to
700 65535, but there was no limit on the former, meaning that integer overflow
701 could in principle occur. The compiled length of a repeated subpattern is
702 now limited to 30,000 bytes in order to prevent this.
703
704 12. Added the optional facility to have named substrings with the same name.
705
706 13. Added the ability to use a named substring as a condition, using the
707 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
708 are numbers (not recommended). Forward references are permitted.
709
710 14. Added forward references in named backreferences (if you see what I mean).
711
712 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
713 pattern could run off the end of the subject. For example, the pattern
714 "(?s)(.{1,5})"8 did this with the subject "ab".
715
716 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
717 PCRE_CASELESS was set when matching characters that were quantified with ?
718 or *.
719
720 17. A character class other than a single negated character that had a minimum
721 but no maximum quantifier - for example [ab]{6,} - was not handled
722 correctly by pce_dfa_exec(). It would match only one character.
723
724 18. A valid (though odd) pattern that looked like a POSIX character
725 class but used an invalid character after [ (for example [[,abc,]]) caused
726 pcre_compile() to give the error "Failed: internal error: code overflow" or
727 in some cases to crash with a glibc free() error. This could even happen if
728 the pattern terminated after [[ but there just happened to be a sequence of
729 letters, a binary zero, and a closing ] in the memory that followed.
730
731 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
732 over the years. Originally (before any Unicode support), just the bottom 8
733 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
734 output from "man perlunicode" includes this:
735
736 The regular expression compiler produces polymorphic opcodes. That
737 is, the pattern adapts to the data and automatically switches to
738 the Unicode character scheme when presented with Unicode data--or
739 instead uses a traditional byte scheme when presented with byte
740 data.
741
742 Sadly, a wide octal escape does not cause a switch, and in a string with
743 no other multibyte characters, these octal escapes are treated as before.
744 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
745 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
746 Unicode string.
747
748 I have not perpetrated such confusion in PCRE. Up till now, it took just
749 the bottom 8 bits, as in old Perl. I have now made octal escapes with
750 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
751 translate to the appropriate multibyte character.
752
753 29. Applied some refactoring to reduce the number of warnings from Microsoft
754 and Borland compilers. This has included removing the fudge introduced
755 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
756 a warning about an unused variable.
757
758 21. PCRE has not included VT (character 0x0b) in the set of whitespace
759 characters since release 4.0, because Perl (from release 5.004) does not.
760 [Or at least, is documented not to: some releases seem to be in conflict
761 with the documentation.] However, when a pattern was studied with
762 pcre_study() and all its branches started with \s, PCRE still included VT
763 as a possible starting character. Of course, this did no harm; it just
764 caused an unnecessary match attempt.
765
766 22. Removed a now-redundant internal flag bit that recorded the fact that case
767 dependency changed within the pattern. This was once needed for "required
768 byte" processing, but is no longer used. This recovers a now-scarce options
769 bit. Also moved the least significant internal flag bit to the most-
770 significant bit of the word, which was not previously used (hangover from
771 the days when it was an int rather than a uint) to free up another bit for
772 the future.
773
774 23. Added support for CRLF line endings as well as CR and LF. As well as the
775 default being selectable at build time, it can now be changed at runtime
776 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
777 specify that it is scanning data with non-default line endings.
778
779 24. Changed the definition of CXXLINK to make it agree with the definition of
780 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
781
782 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
783 recursions. This makes a big different to stack usage for some patterns.
784
785 26. If a subpattern containing a named recursion or subroutine reference such
786 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
787 the space required for the compiled pattern went wrong and gave too small a
788 value. Depending on the environment, this could lead to "Failed: internal
789 error: code overflow at offset 49" or "glibc detected double free or
790 corruption" errors.
791
792 27. Applied patches from Google (a) to support the new newline modes and (b) to
793 advance over multibyte UTF-8 characters in GlobalReplace.
794
795 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
796 difference for some implementation of PCRE in some Windows version.
797
798 29. Added some extra testing facilities to pcretest:
799
800 \q<number> in a data line sets the "match limit" value
801 \Q<number> in a data line sets the "match recursion limt" value
802 -S <number> sets the stack size, where <number> is in megabytes
803
804 The -S option isn't available for Windows.
805
806
807 Version 6.6 06-Feb-06
808 ---------------------
809
810 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
811 in pcreposix.h. I have copied the definition from pcre.h.
812
813 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
814 because pcre.h is no longer a built file.
815
816 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
817 not normally included in the compiled code.
818
819
820 Version 6.5 01-Feb-06
821 ---------------------
822
823 1. When using the partial match feature with pcre_dfa_exec(), it was not
824 anchoring the second and subsequent partial matches at the new starting
825 point. This could lead to incorrect results. For example, with the pattern
826 /1234/, partially matching against "123" and then "a4" gave a match.
827
828 2. Changes to pcregrep:
829
830 (a) All non-match returns from pcre_exec() were being treated as failures
831 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
832 error message is output. Some extra information is given for the
833 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
834 probably the only errors that are likely to be caused by users (by
835 specifying a regex that has nested indefinite repeats, for instance).
836 If there are more than 20 of these errors, pcregrep is abandoned.
837
838 (b) A binary zero was treated as data while matching, but terminated the
839 output line if it was written out. This has been fixed: binary zeroes
840 are now no different to any other data bytes.
841
842 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
843 used to set a locale for matching. The --locale=xxxx long option has
844 been added (no short equivalent) to specify a locale explicitly on the
845 pcregrep command, overriding the environment variables.
846
847 (d) When -B was used with -n, some line numbers in the output were one less
848 than they should have been.
849
850 (e) Added the -o (--only-matching) option.
851
852 (f) If -A or -C was used with -c (count only), some lines of context were
853 accidentally printed for the final match.
854
855 (g) Added the -H (--with-filename) option.
856
857 (h) The combination of options -rh failed to suppress file names for files
858 that were found from directory arguments.
859
860 (i) Added the -D (--devices) and -d (--directories) options.
861
862 (j) Added the -F (--fixed-strings) option.
863
864 (k) Allow "-" to be used as a file name for -f as well as for a data file.
865
866 (l) Added the --colo(u)r option.
867
868 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
869 is not present by default.
870
871 3. A nasty bug was discovered in the handling of recursive patterns, that is,
872 items such as (?R) or (?1), when the recursion could match a number of
873 alternatives. If it matched one of the alternatives, but subsequently,
874 outside the recursion, there was a failure, the code tried to back up into
875 the recursion. However, because of the way PCRE is implemented, this is not
876 possible, and the result was an incorrect result from the match.
877
878 In order to prevent this happening, the specification of recursion has
879 been changed so that all such subpatterns are automatically treated as
880 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
881
882 4. I had overlooked the fact that, in some locales, there are characters for
883 which isalpha() is true but neither isupper() nor islower() are true. In
884 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
885 and ordfeminine) are like this. This affected the treatment of \w and \W
886 when they appeared in character classes, but not when they appeared outside
887 a character class. The bit map for "word" characters is now created
888 separately from the results of isalnum() instead of just taking it from the
889 upper, lower, and digit maps. (Plus the underscore character, of course.)
890
891 5. The above bug also affected the handling of POSIX character classes such as
892 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
893 permanent tables. Instead, the bit maps for such a class were previously
894 created as the appropriate unions of the upper, lower, and digit bitmaps.
895 Now they are created by subtraction from the [[:word:]] class, which has
896 its own bitmap.
897
898 6. The [[:blank:]] character class matches horizontal, but not vertical space.
899 It is created by subtracting the vertical space characters (\x09, \x0a,
900 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
901 subtraction was done in the overall bitmap for a character class, meaning
902 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
903 be recognized. This bug has been fixed.
904
905 7. Patches from the folks at Google:
906
907 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
908 real life, but is still worth protecting against".
909
910 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
911 regular expressions".
912
913 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
914 have it.
915
916 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
917 "configure" and the latter not, in order to fix a problem somebody had
918 with compiling the Arg class on HP-UX.
919
920 (e) Improve the error-handling of the C++ wrapper a little bit.
921
922 (f) New tests for checking recursion limiting.
923
924 8. The pcre_memmove() function, which is used only if the environment does not
925 have a standard memmove() function (and is therefore rarely compiled),
926 contained two bugs: (a) use of int instead of size_t, and (b) it was not
927 returning a result (though PCRE never actually uses the result).
928
929 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
930 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
931 returned instead of calling malloc() with an overflowing number that would
932 most likely cause subsequent chaos.
933
934 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
935
936 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
937 with this option is matched, the nmatch and pmatch options of regexec() are
938 ignored.
939
940 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
941 provided in case anyone wants to the the POSIX interface with UTF-8
942 strings.
943
944 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
945 C++ linking (needed for some HP-UX environments).
946
947 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
948 (unused parameter) and in the pcre_printint() function (omitted "default"
949 switch label when the default is to do nothing).
950
951 15. Added some code to make it possible, when PCRE is compiled as a C++
952 library, to replace subject pointers for pcre_exec() with a smart pointer
953 class, thus making it possible to process discontinuous strings.
954
955 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
956 much the same function. They were added by different people who were trying
957 to make PCRE easy to compile on non-Unix systems. It has been suggested
958 that PCRE_EXPORT be abolished now that there is more automatic apparatus
959 for compiling on Windows systems. I have therefore replaced it with
960 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
961 defaults to "extern" for C or "extern C" for C++, which works fine on
962 Unix-like systems. It is now possible to override the value of PCRE_DATA_
963 SCOPE with something explicit in config.h. In addition:
964
965 (a) pcreposix.h still had just "extern" instead of either of these macros;
966 I have replaced it with PCRE_DATA_SCOPE.
967
968 (b) Functions such as _pcre_xclass(), which are internal to the library,
969 but external in the C sense, all had PCRE_EXPORT in their definitions.
970 This is apparently wrong for the Windows case, so I have removed it.
971 (It makes no difference on Unix-like systems.)
972
973 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
974 of recursive calls to match(). This is different to MATCH_LIMIT because
975 that limits the total number of calls to match(), not all of which increase
976 the depth of recursion. Limiting the recursion depth limits the amount of
977 stack (or heap if NO_RECURSE is set) that is used. The default can be set
978 when PCRE is compiled, and changed at run time. A patch from Google adds
979 this functionality to the C++ interface.
980
981 18. Changes to the handling of Unicode character properties:
982
983 (a) Updated the table to Unicode 4.1.0.
984
985 (b) Recognize characters that are not in the table as "Cn" (undefined).
986
987 (c) I revised the way the table is implemented to a much improved format
988 which includes recognition of ranges. It now supports the ranges that
989 are defined in UnicodeData.txt, and it also amalgamates other
990 characters into ranges. This has reduced the number of entries in the
991 table from around 16,000 to around 3,000, thus reducing its size
992 considerably. I realized I did not need to use a tree structure after
993 all - a binary chop search is just as efficient. Having reduced the
994 number of entries, I extended their size from 6 bytes to 8 bytes to
995 allow for more data.
996
997 (d) Added support for Unicode script names via properties such as \p{Han}.
998
999 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1000 matching that character.
1001
1002 20. When matching a repeated Unicode property with a minimum greater than zero,
1003 (for example \pL{2,}), PCRE could look past the end of the subject if it
1004 reached it while seeking the minimum number of characters. This could
1005 happen only if some of the characters were more than one byte long, because
1006 there is a check for at least the minimum number of bytes.
1007
1008 21. Refactored the implementation of \p and \P so as to be more general, to
1009 allow for more different types of property in future. This has changed the
1010 compiled form incompatibly. Anybody with saved compiled patterns that use
1011 \p or \P will have to recompile them.
1012
1013 22. Added "Any" and "L&" to the supported property types.
1014
1015 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1016 but give a compile time error if the value is greater than 0xff.
1017
1018 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1019 accidentally not being installed or uninstalled.
1020
1021 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1022 made were to insert the current release number. This seemed silly, because
1023 it made things harder for people building PCRE on systems that don't run
1024 "configure". I have turned pcre.h into a distributed file, no longer built
1025 by "configure", with the version identification directly included. There is
1026 no longer a pcre.h.in file.
1027
1028 However, this change necessitated a change to the pcre-config script as
1029 well. It is built from pcre-config.in, and one of the substitutions was the
1030 release number. I have updated configure.ac so that ./configure now finds
1031 the release number by grepping pcre.h.
1032
1033 26. Added the ability to run the tests under valgrind.
1034
1035
1036 Version 6.4 05-Sep-05
1037 ---------------------
1038
1039 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1040 "--" to be printed when multiple files were scanned, even when none of the
1041 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1042 consider it to be a bug, and have restored the previous behaviour.
1043
1044 2. A couple of code tidies to get rid of compiler warnings.
1045
1046 3. The pcretest program used to cheat by referring to symbols in the library
1047 whose names begin with _pcre_. These are internal symbols that are not
1048 really supposed to be visible externally, and in some environments it is
1049 possible to suppress them. The cheating is now confined to including
1050 certain files from the library's source, which is a bit cleaner.
1051
1052 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1053 file's purpose clearer.
1054
1055 5. Reorganized pcre_ucp_findchar().
1056
1057
1058 Version 6.3 15-Aug-05
1059 ---------------------
1060
1061 1. The file libpcre.pc.in did not have general read permission in the tarball.
1062
1063 2. There were some problems when building without C++ support:
1064
1065 (a) If C++ support was not built, "make install" and "make test" still
1066 tried to test it.
1067
1068 (b) There were problems when the value of CXX was explicitly set. Some
1069 changes have been made to try to fix these, and ...
1070
1071 (c) --disable-cpp can now be used to explicitly disable C++ support.
1072
1073 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1074 backslash in a target when C++ was disabled. This confuses some
1075 versions of "make", apparently. Using an intermediate variable solves
1076 this. (Same for CPP_LOBJ.)
1077
1078 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1079 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1080 necessary on certain architectures.
1081
1082 4. Added a setting of -export-symbols-regex to the link command to remove
1083 those symbols that are exported in the C sense, but actually are local
1084 within the library, and not documented. Their names all begin with
1085 "_pcre_". This is not a perfect job, because (a) we have to except some
1086 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1087 available (and never for static libraries). I have made a note to try to
1088 find a way round (a) in the future.
1089
1090
1091 Version 6.2 01-Aug-05
1092 ---------------------
1093
1094 1. There was no test for integer overflow of quantifier values. A construction
1095 such as {1111111111111111} would give undefined results. What is worse, if
1096 a minimum quantifier for a parenthesized subpattern overflowed and became
1097 negative, the calculation of the memory size went wrong. This could have
1098 led to memory overwriting.
1099
1100 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1101
1102 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1103 operating environments where this matters.
1104
1105 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1106 PCRE options from within the C++ wrapper.
1107
1108 5. Named capturing subpatterns were not being correctly counted when a pattern
1109 was compiled. This caused two problems: (a) If there were more than 100
1110 such subpatterns, the calculation of the memory needed for the whole
1111 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1112 back references of the form \12, where the number was greater than 9, were
1113 not recognized as back references, even though there were sufficient
1114 previous subpatterns.
1115
1116 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1117 versions of gcc, e.g. 2.95.4.
1118
1119
1120 Version 6.1 21-Jun-05
1121 ---------------------
1122
1123 1. There was one reference to the variable "posix" in pcretest.c that was not
1124 surrounded by "#if !defined NOPOSIX".
1125
1126 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1127 the cross-check on the old pcre_info() function, for the benefit of the
1128 cut-down version of PCRE that is currently imported into Exim.
1129
1130 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1131 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1132 patterns that start (?i) but I don't think that matters. The use of (?i) is
1133 just an example; this all applies to the other options as well.
1134
1135 4. Since libtool seems to echo the compile commands it is issuing, the output
1136 from "make" can be reduced a bit by putting "@" in front of each libtool
1137 compile command.
1138
1139 5. Patch from the folks at Google for configure.in to be a bit more thorough
1140 in checking for a suitable C++ installation before trying to compile the
1141 C++ stuff. This should fix a reported problem when a compiler was present,
1142 but no suitable headers.
1143
1144 6. The man pages all had just "PCRE" as their title. I have changed them to
1145 be the relevant file name. I have also arranged that these names are
1146 retained in the file doc/pcre.txt, which is a concatenation in text format
1147 of all the man pages except the little individual ones for each function.
1148
1149 7. The NON-UNIX-USE file had not been updated for the different set of source
1150 files that come with release 6. I also added a few comments about the C++
1151 wrapper.
1152
1153
1154 Version 6.0 07-Jun-05
1155 ---------------------
1156
1157 1. Some minor internal re-organization to help with my DFA experiments.
1158
1159 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1160 didn't matter for the library itself when fully configured, but did matter
1161 when compiling without UCP support, or within Exim, where the ucp files are
1162 not imported.
1163
1164 3. Refactoring of the library code to split up the various functions into
1165 different source modules. The addition of the new DFA matching code (see
1166 below) to a single monolithic source would have made it really too
1167 unwieldy, quite apart from causing all the code to be include in a
1168 statically linked application, when only some functions are used. This is
1169 relevant even without the DFA addition now that patterns can be compiled in
1170 one application and matched in another.
1171
1172 The downside of splitting up is that there have to be some external
1173 functions and data tables that are used internally in different modules of
1174 the library but which are not part of the API. These have all had their
1175 names changed to start with "_pcre_" so that they are unlikely to clash
1176 with other external names.
1177
1178 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1179 a different (DFA) algorithm. Although it is slower than the original
1180 function, it does have some advantages for certain types of matching
1181 problem.
1182
1183 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1184 including restarting after a partial match.
1185
1186 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1187 defined when compiling for Windows was sent to me. I have put it into the
1188 code, though I have no means of testing or verifying it.
1189
1190 7. Added the pcre_refcount() auxiliary function.
1191
1192 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1193 match before or at the first newline in the subject string. In pcretest,
1194 the /f option on a pattern can be used to set this.
1195
1196 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1197 would behave wrongly. This has been present in PCRE since release 4.0.
1198
1199 10. A number of changes to the pcregrep command:
1200
1201 (a) Refactored how -x works; insert ^(...)$ instead of setting
1202 PCRE_ANCHORED and checking the length, in preparation for adding
1203 something similar for -w.
1204
1205 (b) Added the -w (match as a word) option.
1206
1207 (c) Refactored the way lines are read and buffered so as to have more
1208 than one at a time available.
1209
1210 (d) Implemented a pcregrep test script.
1211
1212 (e) Added the -M (multiline match) option. This allows patterns to match
1213 over several lines of the subject. The buffering ensures that at least
1214 8K, or the rest of the document (whichever is the shorter) is available
1215 for matching (and similarly the previous 8K for lookbehind assertions).
1216
1217 (f) Changed the --help output so that it now says
1218
1219 -w, --word-regex(p)
1220
1221 instead of two lines, one with "regex" and the other with "regexp"
1222 because that confused at least one person since the short forms are the
1223 same. (This required a bit of code, as the output is generated
1224 automatically from a table. It wasn't just a text change.)
1225
1226 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1227 option but starts with a hyphen. Could be a pattern or a path name
1228 starting with a hyphen, for instance.
1229
1230 (h) "-" can be given as a file name to represent stdin.
1231
1232 (i) When file names are being printed, "(standard input)" is used for
1233 the standard input, for compatibility with GNU grep. Previously
1234 "<stdin>" was used.
1235
1236 (j) The option --label=xxx can be used to supply a name to be used for
1237 stdin when file names are being printed. There is no short form.
1238
1239 (k) Re-factored the options decoding logic because we are going to add
1240 two more options that take data. Such options can now be given in four
1241 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1242
1243 (l) Added the -A, -B, and -C options for requesting that lines of context
1244 around matches be printed.
1245
1246 (m) Added the -L option to print the names of files that do not contain
1247 any matching lines, that is, the complement of -l.
1248
1249 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1250 continue to scan other files.
1251
1252 (o) The -s option was incorrectly implemented. For compatibility with other
1253 greps, it now suppresses the error message for a non-existent or non-
1254 accessible file (but not the return code). There is a new option called
1255 -q that suppresses the output of matching lines, which was what -s was
1256 previously doing.
1257
1258 (p) Added --include and --exclude options to specify files for inclusion
1259 and exclusion when recursing.
1260
1261 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1262 Hopefully, it now does.
1263
1264 12. Missing cast in pcre_study().
1265
1266 13. Added an "uninstall" target to the makefile.
1267
1268 14. Replaced "extern" in the function prototypes in Makefile.in with
1269 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1270 world, but is set differently for Windows.
1271
1272 15. Added a second compiling function called pcre_compile2(). The only
1273 difference is that it has an extra argument, which is a pointer to an
1274 integer error code. When there is a compile-time failure, this is set
1275 non-zero, in addition to the error test pointer being set to point to an
1276 error message. The new argument may be NULL if no error number is required
1277 (but then you may as well call pcre_compile(), which is now just a
1278 wrapper). This facility is provided because some applications need a
1279 numeric error indication, but it has also enabled me to tidy up the way
1280 compile-time errors are handled in the POSIX wrapper.
1281
1282 16. Added VPATH=.libs to the makefile; this should help when building with one
1283 prefix path and installing with another. (Or so I'm told by someone who
1284 knows more about this stuff than I do.)
1285
1286 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1287 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1288 match everything, including newlines. This is not POSIX-compatible, but
1289 somebody wanted the feature. From pcretest it can be activated by using
1290 both the P and the s flags.
1291
1292 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1293
1294 19. libpcre.pc was being incorrectly installed as executable.
1295
1296 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1297 it now also looks for '\r' so that it will work unmodified on Windows.
1298
1299 21. Added Google's contributed C++ wrapper to the distribution.
1300
1301 22. Added some untidy missing memory free() calls in pcretest, to keep
1302 Electric Fence happy when testing.
1303
1304
1305
1306 Version 5.0 13-Sep-04
1307 ---------------------
1308
1309 1. Internal change: literal characters are no longer packed up into items
1310 containing multiple characters in a single byte-string. Each character
1311 is now matched using a separate opcode. However, there may be more than one
1312 byte in the character in UTF-8 mode.
1313
1314 2. The pcre_callout_block structure has two new fields: pattern_position and
1315 next_item_length. These contain the offset in the pattern to the next match
1316 item, and its length, respectively.
1317
1318 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1319 insertion of callouts before each pattern item. Added the /C option to
1320 pcretest to make use of this.
1321
1322 4. On the advice of a Windows user, the lines
1323
1324 #if defined(_WIN32) || defined(WIN32)
1325 _setmode( _fileno( stdout ), 0x8000 );
1326 #endif /* defined(_WIN32) || defined(WIN32) */
1327
1328 have been added to the source of pcretest. This apparently does useful
1329 magic in relation to line terminators.
1330
1331 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1332 for the benefit of those environments where the "b" makes a difference.
1333
1334 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1335 to know about it. I have put a hack into configure.in that adds in code
1336 to set GCC=yes if CC=icc. This seems to end up at a point in the
1337 generated configure script that is early enough to affect the setting of
1338 compiler options, which is what is needed, but I have no means of testing
1339 whether it really works. (The user who reported this had patched the
1340 generated configure script, which of course I cannot do.)
1341
1342 LATER: After change 22 below (new libtool files), the configure script
1343 seems to know about icc (and also ecc). Therefore, I have commented out
1344 this hack in configure.in.
1345
1346 7. Added support for pkg-config (2 patches were sent in).
1347
1348 8. Negated POSIX character classes that used a combination of internal tables
1349 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1350 [[:^ascii]]. Typically, they would match almost any characters. The other
1351 POSIX classes were not broken in this way.
1352
1353 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1354 to find the match, as PCRE was deluded into thinking that the match had to
1355 start at the start point or following a newline. The same bug applied to
1356 patterns with negative forward assertions or any backward assertions
1357 preceding ".*" at the start, unless the pattern required a fixed first
1358 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1359
1360 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1361 starting at the last subject character, bytes beyond the end of the subject
1362 string were read.
1363
1364 11. Renamed the variable "class" as "classbits" to make life easier for C++
1365 users. (Previously there was a macro definition, but it apparently wasn't
1366 enough.)
1367
1368 12. Added the new field "tables" to the extra data so that tables can be passed
1369 in at exec time, or the internal tables can be re-selected. This allows
1370 a compiled regex to be saved and re-used at a later time by a different
1371 program that might have everything at different addresses.
1372
1373 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1374 -R library as well as a -L library.
1375
1376 14. The debugging options of pcretest (-d on the command line or D on a
1377 pattern) showed incorrect output for anything following an extended class
1378 that contained multibyte characters and which was followed by a quantifier.
1379
1380 15. Added optional support for general category Unicode character properties
1381 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1382 support. It adds about 90K to the size of the library. The meanings of the
1383 inbuilt class escapes such as \d and \s have NOT been changed.
1384
1385 16. Updated pcredemo.c to include calls to free() to release the memory for the
1386 compiled pattern.
1387
1388 17. The generated file chartables.c was being created in the source directory
1389 instead of in the building directory. This caused the build to fail if the
1390 source directory was different from the building directory, and was
1391 read-only.
1392
1393 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1394 file. No doubt somebody will tell me if they don't make sense... Also added
1395 Dan Mooney's comments about building on OpenVMS.
1396
1397 19. Added support for partial matching via the PCRE_PARTIAL option for
1398 pcre_exec() and the \P data escape in pcretest.
1399
1400 20. Extended pcretest with 3 new pattern features:
1401
1402 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1403 write the compiled pattern to the file whose name is "rest-of-line".
1404 This is a straight binary dump of the data, with the saved pointer to
1405 the character tables forced to be NULL. The study data, if any, is
1406 written too. After writing, pcretest reads a new pattern.
1407
1408 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1409 compiled pattern from the given file. There must not be any
1410 occurrences of "<" in the file name (pretty unlikely); if there are,
1411 pcretest will instead treat the initial "<" as a pattern delimiter.
1412 After reading in the pattern, pcretest goes on to read data lines as
1413 usual.
1414
1415 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1416 and 16-bit fields in a compiled pattern, to simulate a pattern that
1417 was compiled on a host of opposite endianness.
1418
1419 21. The pcre-exec() function can now cope with patterns that were compiled on
1420 hosts of opposite endianness, with this restriction:
1421
1422 As for any compiled expression that is saved and used later, the tables
1423 pointer field cannot be preserved; the extra_data field in the arguments
1424 to pcre_exec() should be used to pass in a tables address if a value
1425 other than the default internal tables were used at compile time.
1426
1427 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1428 now diagnosed as an error. Previously, most of the time, a negative number
1429 would have been treated as zero, but if in addition "ovector" was passed as
1430 NULL, a crash could occur.
1431
1432 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1433 new versions from the libtool 1.5 distribution (the last one is a copy of
1434 a file called libtool.m4). This seems to have fixed the need to patch
1435 "configure" to support Darwin 1.3 (which I used to do). However, I still
1436 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1437 workstation).
1438
1439 24. Changed the PCRE licence to be the more standard "BSD" licence.
1440
1441
1442 Version 4.5 01-Dec-03
1443 ---------------------
1444
1445 1. There has been some re-arrangement of the code for the match() function so
1446 that it can be compiled in a version that does not call itself recursively.
1447 Instead, it keeps those local variables that need separate instances for
1448 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1449 needs to "recurse". Keeping track of where control must go is done by means
1450 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1451 hide most of the details from the main code, and operates only if
1452 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1453 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1454 operating.
1455
1456 To make it easier for callers to provide specially tailored get/free
1457 functions for this usage, two new functions, pcre_stack_malloc, and
1458 pcre_stack_free, are used. They are always called in strict stacking order,
1459 and the size of block requested is always the same.
1460
1461 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1462 PCRE has been compiled to use the stack or the heap for recursion. The
1463 -C option of pcretest uses this to show which version is compiled.
1464
1465 A new data escape \S, is added to pcretest; it causes the amounts of store
1466 obtained and freed by both kinds of malloc/free at match time to be added
1467 to the output.
1468
1469 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1470 what's available on my current Linux desktop machine.
1471
1472 3. When matching a UTF-8 string, the test for a valid string at the start has
1473 been extended. If start_offset is not zero, PCRE now checks that it points
1474 to a byte that is the start of a UTF-8 character. If not, it returns
1475 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1476 this is necessary because there may be backward assertions in the pattern.
1477 When matching the same subject several times, it may save resources to use
1478 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1479
1480 4. The code for checking the validity of UTF-8 strings has been tightened so
1481 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1482 containing "overlong sequences".
1483
1484 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1485 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1486 should have been "&", but it just so happened that all the cases this let
1487 through by mistake were picked up later in the function.
1488
1489 6. I had used a variable called "isblank" - this is a C99 function, causing
1490 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1491
1492 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1493 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1494 so the version is shown; (c) stop "make test" echoing "./RunTest".
1495
1496 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1497
1498 9. The prototype for memmove() for systems that don't have it was using
1499 size_t, but the inclusion of the header that defines size_t was later. I've
1500 moved the #includes for the C headers earlier to avoid this.
1501
1502 10. Added some adjustments to the code to make it easier to compiler on certain
1503 special systems:
1504
1505 (a) Some "const" qualifiers were missing.
1506 (b) Added the macro EXPORT before all exported functions; by default this
1507 is defined to be empty.
1508 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1509 that it reads its output file name as an argument instead of writing
1510 to the standard output and assuming this can be redirected.
1511
1512 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1513 class containing characters with values greater than 255, PCRE compilation
1514 went into a loop.
1515
1516 12. A recursive reference to a subpattern that was within another subpattern
1517 that had a minimum quantifier of zero caused PCRE to crash. For example,
1518 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1519 recursion. If the recursively-called subpattern itself had a zero repeat,
1520 that was OK.
1521
1522 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1523 buffer into which it was copied (for escape processing) was still set at
1524 1024, so long lines caused crashes.
1525
1526 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1527 "internal error: code overflow...". This applied to any character class
1528 that was followed by a possessive quantifier.
1529
1530 15. Modified the Makefile to add libpcre.la as a prerequisite for
1531 libpcreposix.la because I was told this is needed for a parallel build to
1532 work.
1533
1534 16. If a pattern that contained .* following optional items at the start was
1535 studied, the wrong optimizing data was generated, leading to matching
1536 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1537 matching string must start with a or b or c. The correct conclusion for
1538 this pattern is that a match can start with any character.
1539
1540
1541 Version 4.4 13-Aug-03
1542 ---------------------
1543
1544 1. In UTF-8 mode, a character class containing characters with values between
1545 127 and 255 was not handled correctly if the compiled pattern was studied.
1546 In fixing this, I have also improved the studying algorithm for such
1547 classes (slightly).
1548
1549 2. Three internal functions had redundant arguments passed to them. Removal
1550 might give a very teeny performance improvement.
1551
1552 3. Documentation bug: the value of the capture_top field in a callout is *one
1553 more than* the number of the hightest numbered captured substring.
1554
1555 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1556 in incorrectly linking with a previously installed version. They now link
1557 explicitly with libpcre.la.
1558
1559 5. configure.in no longer needs to recognize Cygwin specially.
1560
1561 6. A problem in pcre.in for Windows platforms is fixed.
1562
1563 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1564 pcretest, it used to include the size of the study block as part of its
1565 output. Unfortunately, the structure contains a field that has a different
1566 size on different hardware architectures. This meant that the tests that
1567 showed this size failed. As the block is currently always of a fixed size,
1568 this information isn't actually particularly useful in pcretest output, so
1569 I have just removed it.
1570
1571 8. Three pre-processor statements accidentally did not start in column 1.
1572 Sadly, there are *still* compilers around that complain, even though
1573 standard C has not required this for well over a decade. Sigh.
1574
1575 9. In pcretest, the code for checking callouts passed small integers in the
1576 callout_data field, which is a void * field. However, some picky compilers
1577 complained about the casts involved for this on 64-bit systems. Now
1578 pcretest passes the address of the small integer instead, which should get
1579 rid of the warnings.
1580
1581 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1582 both compile and run time, and gives an error if an invalid UTF-8 sequence
1583 is found. There is a option for disabling this check in cases where the
1584 string is known to be correct and/or the maximum performance is wanted.
1585
1586 11. In response to a bug report, I changed one line in Makefile.in from
1587
1588 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1589 to
1590 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1591
1592 to look similar to other lines, but I have no way of telling whether this
1593 is the right thing to do, as I do not use Windows. No doubt I'll get told
1594 if it's wrong...
1595
1596
1597 Version 4.3 21-May-03
1598 ---------------------
1599
1600 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1601 Makefile.
1602
1603 2. Some refactoring to improve the quality of the code:
1604
1605 (i) The utf8_table... variables are now declared "const".
1606
1607 (ii) The code for \cx, which used the "case flipping" table to upper case
1608 lower case letters, now just substracts 32. This is ASCII-specific,
1609 but the whole concept of \cx is ASCII-specific, so it seems
1610 reasonable.
1611
1612 (iii) PCRE was using its character types table to recognize decimal and
1613 hexadecimal digits in the pattern. This is silly, because it handles
1614 only 0-9, a-f, and A-F, but the character types table is locale-
1615 specific, which means strange things might happen. A private
1616 table is now used for this - though it costs 256 bytes, a table is
1617 much faster than multiple explicit tests. Of course, the standard
1618 character types table is still used for matching digits in subject
1619 strings against \d.
1620
1621 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1622 ending in _t are). So I've renamed it as ESC_tee.
1623
1624 3. The first argument for regexec() in the POSIX wrapper should have been
1625 defined as "const".
1626
1627 4. Changed pcretest to use malloc() for its buffers so that they can be
1628 Electric Fenced for debugging.
1629
1630 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1631 to read one or more bytes before the start of the subject string. Often this
1632 had no effect on PCRE's behaviour, but in some circumstances it could
1633 provoke a segmentation fault.
1634
1635 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1636 to try to read one or more bytes before the start of the subject string.
1637
1638 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1639 UTF-8 support could misbehave in various ways if the subject string
1640 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1641 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1642 back over UTF-8 characters.)
1643
1644
1645 Version 4.2 14-Apr-03
1646 ---------------------
1647
1648 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1649
1650 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1651 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1652 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1653 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1654 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1655 and BUILD_EXEEXT
1656 Note: automatic setting of the BUILD variables is not yet working
1657 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1658 compile-time but not at link-time
1659 [LINK]: use for linking executables only
1660 make different versions for Windows and non-Windows
1661 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1662 libraries
1663 [LINK_FOR_BUILD]: new variable
1664 [OBJEXT]: use throughout
1665 [EXEEXT]: use throughout
1666 <winshared>: new target
1667 <wininstall>: new target
1668 <dftables.o>: use native compiler
1669 <dftables>: use native linker
1670 <install>: handle Windows platform correctly
1671 <clean>: ditto
1672 <check>: ditto
1673 copy DLL to top builddir before testing
1674
1675 As part of these changes, -no-undefined was removed again. This was reported
1676 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1677 in any case.
1678
1679 3. Some tidies to get rid of compiler warnings:
1680
1681 . In the match_data structure, match_limit was an unsigned long int, whereas
1682 match_call_count was an int. I've made them both unsigned long ints.
1683
1684 . In pcretest the fact that a const uschar * doesn't automatically cast to
1685 a void * provoked a warning.
1686
1687 . Turning on some more compiler warnings threw up some "shadow" variables
1688 and a few more missing casts.
1689
1690 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1691 option, a class that contained a single character with a value between 128
1692 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1693
1694 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1695 option, a class that contained several characters, but with at least one
1696 whose value was between 128 and 255 caused PCRE to crash.
1697
1698
1699 Version 4.1 12-Mar-03
1700 ---------------------
1701
1702 1. Compiling with gcc -pedantic found a couple of places where casts were
1703 needed, and a string in dftables.c that was longer than standard compilers are
1704 required to support.
1705
1706 2. Compiling with Sun's compiler found a few more places where the code could
1707 be tidied up in order to avoid warnings.
1708
1709 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1710 first of these names is deprecated in the latest Autoconf in favour of the name
1711 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1712 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1713 analogy I have changed it to CFLAGS_FOR_BUILD.
1714
1715 4. Added -no-undefined to the linking command in the Makefile, because this is
1716 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1717 linking step for the pcreposix library.
1718
1719 5. PCRE was failing to diagnose the case of two named groups with the same
1720 name.
1721
1722 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1723 literal character that is needed in the subject for a match, and scans along to
1724 ensure that it is present before embarking on the full matching process. This
1725 saves time in cases of nested unlimited repeats that are never going to match.
1726 Problem: the scan can take a lot of time if the subject is very long (e.g.
1727 megabytes), thus penalizing straightforward matches. It is now done only if the
1728 amount of subject to be scanned is less than 1000 bytes.
1729
1730 7. A lesser problem with the same optimization is that it was recording the
1731 first character of an anchored pattern as "needed", thus provoking a search
1732 right along the subject, even when the first match of the pattern was going to
1733 fail. The "needed" character is now not set for anchored patterns, unless it
1734 follows something in the pattern that is of non-fixed length. Thus, it still
1735 fulfils its original purpose of finding quick non-matches in cases of nested
1736 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1737
1738
1739 Version 4.0 17-Feb-03
1740 ---------------------
1741
1742 1. If a comment in an extended regex that started immediately after a meta-item
1743 extended to the end of string, PCRE compiled incorrect data. This could lead to
1744 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1745
1746 2. Moved to autoconf 2.53 and libtool 1.4.2.
1747
1748 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1749 the special perltest8 script is no longer needed - all the tests can be run
1750 from a single perltest script.
1751
1752 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1753 by \s. It has now been removed in PCRE. This means it isn't recognized as
1754 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1755 class [:space:] *does* include VT, thereby creating a mess.
1756
1757 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1758 space and tab.
1759
1760 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1761 its new features into the main test script, reducing the number of scripts.
1762
1763 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1764 were backward compatible, and made the (?i) apply to the whole pattern, as if
1765 /i were given. Now it behaves more logically, and applies the option setting
1766 only to what follows. PCRE has been changed to follow suit. However, if it
1767 finds options settings right at the start of the pattern, it extracts them into
1768 the global options, as before. Thus, they show up in the info data.
1769
1770 8. Added support for the \Q...\E escape sequence. Characters in between are
1771 treated as literals. This is slightly different from Perl in that $ and @ are
1772 also handled as literals inside the quotes. In Perl, they will cause variable
1773 interpolation. Note the following examples:
1774
1775 Pattern PCRE matches Perl matches
1776
1777 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1778 \Qabc\$xyz\E abc\$xyz abc\$xyz
1779 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1780
1781 For compatibility with Perl, \Q...\E sequences are recognized inside character
1782 classes as well as outside them.
1783
1784 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1785 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1786 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1787 signed/unsigned warnings.
1788
1789 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1790 option for pcretest, so I've replaced it by a simple function that does just
1791 that job.
1792
1793 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1794 "pcregrep -".
1795
1796 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1797 Java package. This provides some syntactic sugar for simple cases of what my
1798 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1799 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1800 item, you can use this simplified notation. Note that only makes sense with
1801 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1802 greediness, whatever the setting of the PCRE_UNGREEDY option.
1803
1804 13. A change of greediness default within a pattern was not taking effect at
1805 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1806 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1807 was abstracted outside.
1808
1809 14. PCRE now supports the \G assertion. It is true when the current matching
1810 position is at the start point of the match. This differs from \A when the
1811 starting offset is non-zero. Used with the /g option of pcretest (or similar
1812 code), it works in the same way as it does for Perl's /g option. If all
1813 alternatives of a regex begin with \G, the expression is anchored to the start
1814 match position, and the "anchored" flag is set in the compiled expression.
1815
1816 15. Some bugs concerning the handling of certain option changes within patterns
1817 have been fixed. These applied to options other than (?ims). For example,
1818 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1819 been the other way round. Some of this was related to change 7 above.
1820
1821 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1822 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1823 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1824 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1825
1826 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1827 mode. Unlike ".", it always matches newline, whatever the setting of
1828 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1829 assertions. Perl allows it, but it doesn't (in general) work because it can't
1830 calculate the length of the lookbehind. At least, that's the case for Perl
1831 5.8.0 - I've been told they are going to document that it doesn't work in
1832 future.
1833
1834 18. Added an error diagnosis for escapes that PCRE does not support: these are
1835 \L, \l, \N, \P, \p, \U, \u, and \X.
1836
1837 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1838 reading past the end of the pattern in cases such as /[abcd/.
1839
1840 20. PCRE was getting more memory than necessary for patterns with classes that
1841 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1842
1843 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1844 compiling PCRE for use with Virtual Pascal.
1845
1846 22. Small fix to the Makefile to make it work properly if the build is done
1847 outside the source tree.
1848
1849 23. Added a new extension: a condition to go with recursion. If a conditional
1850 subpattern starts with (?(R) the "true" branch is used if recursion has
1851 happened, whereas the "false" branch is used only at the top level.
1852
1853 24. When there was a very long string of literal characters (over 255 bytes
1854 without UTF support, over 250 bytes with UTF support), the computation of how
1855 much memory was required could be incorrect, leading to segfaults or other
1856 strange effects.
1857
1858 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1859 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1860 there was a subsequent back reference to those brackets. This meant that, for
1861 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1862 possible to check for precisely this case. All we can do is abandon the
1863 optimization if .* occurs inside capturing brackets when there are any back
1864 references whatsoever. (See below for a better fix that came later.)
1865
1866 26. The handling of the optimization for finding the first character of a
1867 non-anchored pattern, and for finding a character that is required later in the
1868 match were failing in some cases. This didn't break the matching; it just
1869 failed to optimize when it could. The way this is done has been re-implemented.
1870
1871 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1872
1873 28. Added a new feature that provides some of the functionality that Perl
1874 provides with (?{...}). The facility is termed a "callout". The way it is done
1875 in PCRE is for the caller to provide an optional function, by setting
1876 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1877 global variable. By default it is unset, which disables all calling out. To get
1878 the function called, the regex must include (?C) at appropriate points. This
1879 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1880 This provides a means of identifying different callout points. When PCRE
1881 reaches such a point in the regex, if pcre_callout has been set, the external
1882 function is called. It is provided with data in a structure called
1883 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1884 matching continues; if it returns a non-zero value, the match at the current
1885 point fails. However, backtracking will occur if possible. [This was changed
1886 later and other features added - see item 49 below.]
1887
1888 29. pcretest is upgraded to test the callout functionality. It provides a
1889 callout function that displays information. By default, it shows the start of
1890 the match and the current position in the text. There are some new data escapes
1891 to vary what happens:
1892
1893 \C+ in addition, show current contents of captured substrings
1894 \C- do not supply a callout function
1895 \C!n return 1 when callout number n is reached
1896 \C!n!m return 1 when callout number n is reached for the mth time
1897
1898 30. If pcregrep was called with the -l option and just a single file name, it
1899 output "<stdin>" if a match was found, instead of the file name.
1900
1901 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1902 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1903 pcre_exec(). This saves a malloc/free per call. The default value of
1904 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1905 when configuring.
1906
1907 32. The default maximum size of a compiled pattern is 64K. There have been a
1908 few cases of people hitting this limit. The code now uses macros to handle the
1909 storing of links as offsets within the compiled pattern. It defaults to 2-byte
1910 links, but this can be changed to 3 or 4 bytes by --with-link-size when
1911 configuring. Tests 2 and 5 work only with 2-byte links because they output
1912 debugging information about compiled patterns.
1913
1914 33. Internal code re-arrangements:
1915
1916 (a) Moved the debugging function for printing out a compiled regex into
1917 its own source file (printint.c) and used #include to pull it into
1918 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1919 separate copies.
1920
1921 (b) Defined the list of op-code names for debugging as a macro in
1922 internal.h so that it is next to the definition of the opcodes.
1923
1924 (c) Defined a table of op-code lengths for simpler skipping along compiled
1925 code. This is again a macro in internal.h so that it is next to the
1926 definition of the opcodes.
1927
1928 34. Added support for recursive calls to individual subpatterns, along the
1929 lines of Robin Houston's patch (but implemented somewhat differently).
1930
1931 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1932 allow it to read and process whole directories in Win32. This code was
1933 contributed by Lionel Fourquaux; it has not been tested by me.
1934
1935 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1936 used to name a group. Names consist of alphanumerics and underscores, and must
1937 be unique. Back references use the syntax (?P=name) and recursive calls use
1938 (?P>name) which is a PCRE extension to the Python extension. Groups still have
1939 numbers. The function pcre_fullinfo() can be used after compilation to extract
1940 a name/number map. There are three relevant calls:
1941
1942 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
1943 PCRE_INFO_NAMECOUNT yields the number of entries
1944 PCRE_INFO_NAMETABLE yields a pointer to the map.
1945
1946 The map is a vector of fixed-size entries. The size of each entry depends on
1947 the length of the longest name used. The first two bytes of each entry are the
1948 group number, most significant byte first. There follows the corresponding
1949 name, zero terminated. The names are in alphabetical order.
1950
1951 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1952 case instead of 255. Making it the same both with and without UTF-8 support
1953 means that the same test output works with both.
1954
1955 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1956 calling malloc() with a zero argument.
1957
1958 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1959 optimization. I've improved things by keeping a bitmap of backreferences with
1960 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1961 fact referenced, the optimization can be applied. It is unlikely that a
1962 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1963 the match to follow \n) will appear inside brackets with a number greater than
1964 31, but if it does, any back reference > 31 suppresses the optimization.
1965
1966 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1967 of disabling numbered capturing parentheses. Any opening parenthesis that is
1968 not followed by ? behaves as if it were followed by ?: but named parentheses
1969 can still be used for capturing (and they will acquire numbers in the usual
1970 way).
1971
1972 41. Redesigned the return codes from the match() function into yes/no/error so
1973 that errors can be passed back from deep inside the nested calls. A malloc
1974 failure while inside a recursive subpattern call now causes the
1975 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1976
1977 42. It is now possible to set a limit on the number of times the match()
1978 function is called in a call to pcre_exec(). This facility makes it possible to
1979 limit the amount of recursion and backtracking, though not in a directly
1980 obvious way, because the match() function is used in a number of different
1981 circumstances. The count starts from zero for each position in the subject
1982 string (for non-anchored patterns). The default limit is, for compatibility, a
1983 large number, namely 10 000 000. You can change this in two ways:
1984
1985 (a) When configuring PCRE before making, you can use --with-match-limit=n
1986 to set a default value for the compiled library.
1987
1988 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1989 a different value is set. See 45 below.
1990
1991 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
1992
1993 43. Added a new function pcre_config(int, void *) to enable run-time extraction
1994 of things that can be changed at compile time. The first argument specifies
1995 what is wanted and the second points to where the information is to be placed.
1996 The current list of available information is:
1997
1998 PCRE_CONFIG_UTF8
1999
2000 The output is an integer that is set to one if UTF-8 support is available;
2001 otherwise it is set to zero.
2002
2003 PCRE_CONFIG_NEWLINE
2004
2005 The output is an integer that it set to the value of the code that is used for
2006 newline. It is either LF (10) or CR (13).
2007
2008 PCRE_CONFIG_LINK_SIZE
2009
2010 The output is an integer that contains the number of bytes used for internal
2011 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2012
2013 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2014
2015 The output is an integer that contains the threshold above which the POSIX
2016 interface uses malloc() for output vectors. See item 31 above.
2017
2018 PCRE_CONFIG_MATCH_LIMIT
2019
2020 The output is an unsigned integer that contains the default limit of the number
2021 of match() calls in a pcre_exec() execution. See 42 above.
2022
2023 44. pcretest has been upgraded by the addition of the -C option. This causes it
2024 to extract all the available output from the new pcre_config() function, and to
2025 output it. The program then exits immediately.
2026
2027 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2028 order to support additional features. One way would have been to define
2029 pcre_exec2() (for example) with extra arguments, but this would not have been
2030 extensible, and would also have required all calls to the original function to
2031 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2032 is used for passing in "extra" data from pcre_study().
2033
2034 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2035 contains the following fields:
2036
2037 flags a bitmap indicating which of the following fields are set
2038 study_data opaque data from pcre_study()
2039 match_limit a way of specifying a limit on match() calls for a specific
2040 call to pcre_exec()
2041 callout_data data for callouts (see 49 below)
2042
2043 The flag bits are also defined in pcre.h, and are
2044
2045 PCRE_EXTRA_STUDY_DATA
2046 PCRE_EXTRA_MATCH_LIMIT
2047 PCRE_EXTRA_CALLOUT_DATA
2048
2049 The pcre_study() function now returns one of these new pcre_extra blocks, with
2050 the actual study data pointed to by the study_data field, and the
2051 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2052 before. That is, this change is entirely upwards-compatible and requires no
2053 change to existing code.
2054
2055 If you want to pass in additional data to pcre_exec(), you can either place it
2056 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2057 block.
2058
2059 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2060 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2061 times with different match limits, until it finds the minimum value needed for
2062 pcre_exec() to complete. The value is then output. This can be instructive; for
2063 most simple matches the number is quite small, but for pathological cases it
2064 gets very large very quickly.
2065
2066 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2067 returns the size of the data block pointed to by the study_data field in a
2068 pcre_extra block, that is, the value that was passed as the argument to
2069 pcre_malloc() when PCRE was getting memory in which to place the information
2070 created by pcre_study(). The fourth argument should point to a size_t variable.
2071 pcretest has been extended so that this information is shown after a successful
2072 pcre_study() call when information about the compiled regex is being displayed.
2073
2074 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2075 because what follows is always an absolute path. (Later: it turns out that this
2076 is more than cosmetic for MinGW, because it doesn't like empty path
2077 components.)
2078
2079 49. Some changes have been made to the callout feature (see 28 above):
2080
2081 (i) A callout function now has three choices for what it returns:
2082
2083 0 => success, carry on matching
2084 > 0 => failure at this point, but backtrack if possible
2085 < 0 => serious error, return this value from pcre_exec()
2086
2087 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2088 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2089 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2090 use by callout functions. It will never be used by PCRE itself.
2091
2092 (ii) The pcre_extra structure (see 45 above) has a void * field called
2093 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2094 pcre_callout_block structure has a field of the same name. The contents of
2095 the field passed in the pcre_extra structure are passed to the callout
2096 function in the corresponding field in the callout block. This makes it
2097 easier to use the same callout-containing regex from multiple threads. For
2098 testing, the pcretest program has a new data escape
2099
2100 \C*n pass the number n (may be negative) as callout_data
2101
2102 If the callout function in pcretest receives a non-zero value as
2103 callout_data, it returns that value.
2104
2105 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2106 there were some redundant $(CFLAGS) in commands that are now specified as
2107 $(LINK), which already includes $(CFLAGS).
2108
2109 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2110 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2111 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2112 one-byte characters throughout. Note that case-insensitive matching applies
2113 only to characters whose values are less than 256. PCRE doesn't support the
2114 notion of cases for higher-valued characters.
2115
2116 (i) A character class whose characters are all within 0-255 is handled as
2117 a bit map, and the map is inverted for negative classes. Previously, a
2118 character > 255 always failed to match such a class; however it should
2119 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2120
2121 (ii) A negated character class with a single character < 255 is coded as
2122 "not this character" (OP_NOT). This wasn't working properly when the test
2123 character was multibyte, either singly or repeated.
2124
2125 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2126 mode, for example: \x{100}{2,3}.
2127
2128 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2129 singly or repeated) now correctly test multibyte characters. However,
2130 PCRE doesn't recognize any characters with values greater than 255 as
2131 digits, spaces, or word characters. Such characters always match \D, \S,
2132 and \W, and never match \d, \s, or \w.
2133
2134 (v) Classes may now contain characters and character ranges with values
2135 greater than 255. For example: [ab\x{100}-\x{400}].
2136
2137 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2138 PCRE in UTF-8 mode.
2139
2140 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2141 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2142 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2143 value.)
2144
2145 53. The single man page has become too large. I have therefore split it up into
2146 a number of separate man pages. These also give rise to individual HTML pages;
2147 these are now put in a separate directory, and there is an index.html page that
2148 lists them all. Some hyperlinking between the pages has been installed.
2149
2150 54. Added convenience functions for handling named capturing parentheses.
2151
2152 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2153 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2154 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2155 are faulted.
2156
2157 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2158 calling configure. These values are used when compiling the dftables.c program
2159 which is run to generate the source of the default character tables. They
2160 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2161 you will need to set these values.
2162
2163 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2164
2165
2166 Version 3.9 02-Jan-02
2167 ---------------------
2168
2169 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2170
2171 2. If --disable-static was given, the building process failed when trying to
2172 build pcretest and pcregrep. (For some reason it was using libtool to compile
2173 them, which is not right, as they aren't part of the library.)
2174
2175
2176 Version 3.8 18-Dec-01
2177 ---------------------
2178
2179 1. The experimental UTF-8 code was completely screwed up. It was packing the
2180 bytes in the wrong order. How dumb can you get?
2181
2182
2183 Version 3.7 29-Oct-01
2184 ---------------------
2185
2186 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2187 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2188 this didn't happen under Solaris 8, where I normally test things.
2189
2190 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2191 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2192 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2193 this fix an hour or so after the initial 3.7 release.)
2194
2195
2196 Version 3.6 23-Oct-01
2197 ---------------------
2198
2199 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2200 offsets passed as NULL with zero offset count.
2201
2202 2. The config.guess and config.sub files had not been updated when I moved to
2203 the latest autoconf.
2204
2205
2206 Version 3.5 15-Aug-01
2207 ---------------------
2208
2209 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2210 had been forgotten.
2211
2212 2. By using declared but undefined structures, we can avoid using "void"
2213 definitions in pcre.h while keeping the internal definitions of the structures
2214 private.
2215
2216 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2217 user point of view, this means that both static and shared libraries are built
2218 by default, but this can be individually controlled. More of the work of
2219 handling this static/shared cases is now inside libtool instead of PCRE's make
2220 file.
2221
2222 4. The pcretest utility is now installed along with pcregrep because it is
2223 useful for users (to test regexs) and by doing this, it automatically gets
2224 relinked by libtool. The documentation has been turned into a man page, so
2225 there are now .1, .txt, and .html versions in /doc.
2226
2227 5. Upgrades to pcregrep:
2228 (i) Added long-form option names like gnu grep.
2229 (ii) Added --help to list all options with an explanatory phrase.
2230 (iii) Added -r, --recursive to recurse into sub-directories.
2231 (iv) Added -f, --file to read patterns from a file.
2232
2233 6. pcre_exec() was referring to its "code" argument before testing that
2234 argument for NULL (and giving an error if it was NULL).
2235
2236 7. Upgraded Makefile.in to allow for compiling in a different directory from
2237 the source directory.
2238
2239 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2240 options bits, the pointer it was passed was to an int instead of to an unsigned
2241 long int. This mattered only on 64-bit systems.
2242
2243 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2244 generated) instead of pcre.in, which it its source. Also made the same change
2245 in several of the .c files.
2246
2247 10. A new release of gcc defines printf() as a macro, which broke pcretest
2248 because it had an ifdef in the middle of a string argument for printf(). Fixed
2249 by using separate calls to printf().
2250
2251 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2252 script, to force use of CR or LF instead of \n in the source. On non-Unix
2253 systems, the value can be set in config.h.
2254
2255 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2256 absolute limit. Changed the text of the error message to make this clear, and
2257 likewise updated the man page.
2258
2259 13. The limit of 99 on the number of capturing subpatterns has been removed.
2260 The new limit is 65535, which I hope will not be a "real" limit.
2261
2262
2263 Version 3.4 22-Aug-00
2264 ---------------------
2265
2266 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2267
2268 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2269
2270
2271 Version 3.3 01-Aug-00
2272 ---------------------
2273
2274 1. If an octal character was given, but the value was greater than \377, it
2275 was not getting masked to the least significant bits, as documented. This could
2276 lead to crashes in some systems.
2277
2278 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2279 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2280
2281 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2282 These just pass their arguments on to (pcre_free)(), but they are provided
2283 because some uses of PCRE bind it to non-C systems that can call its functions,
2284 but cannot call free() or pcre_free() directly.
2285
2286 4. Add "make test" as a synonym for "make check". Corrected some comments in
2287 the Makefile.
2288
2289 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2290 Makefile.
2291
2292 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2293 command called pgrep for grepping around the active processes.
2294
2295 7. Added the beginnings of support for UTF-8 character strings.
2296
2297 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2298 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2299 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2300 out for the ar command.)
2301
2302
2303 Version 3.2 12-May-00
2304 ---------------------
2305
2306 This is purely a bug fixing release.
2307
2308 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2309 of ZA. This was just one example of several cases that could provoke this bug,
2310 which was introduced by change 9 of version 2.00. The code for breaking
2311 infinite loops after an iteration that matches an empty string was't working
2312 correctly.
2313
2314 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2315 when matched against abbab (for example). After matching an empty string, it
2316 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2317 caused it to match further down the string than it should.
2318
2319 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2320 was there because it doesn't seem to be needed, and it causes trouble on some
2321 systems, as it is not a Standard C header. It has been removed.
2322
2323 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2324 were reported on the Macintosh. The changes were from
2325
2326 while ((c = *(++ptr)) != 0 && c != '\n');
2327 to
2328 while ((c = *(++ptr)) != 0 && c != '\n') ;
2329
2330 Totally extraordinary, but if that's what it takes...
2331
2332 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2333 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2334 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2335 assumes the way PCRE uses memmove() (always moving upwards).
2336
2337 6. PCRE is being used in one environment where strchr() is not available. There
2338 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2339 faster code anyway.
2340
2341
2342 Version 3.1 09-Feb-00
2343 ---------------------
2344
2345 The only change in this release is the fixing of some bugs in Makefile.in for
2346 the "install" target:
2347
2348 (1) It was failing to install pcreposix.h.
2349
2350 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2351
2352
2353 Version 3.0 01-Feb-00
2354 ---------------------
2355
2356 1. Add support for the /+ modifier to perltest (to output $` like it does in
2357 pcretest).
2358
2359 2. Add support for the /g modifier to perltest.
2360
2361 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2362 matches null strings.
2363
2364 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2365 pattern. Perl treats empty patterns specially - it reuses the most recent
2366 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2367 effect.
2368
2369 5. The POSIX interface was broken in that it was just handing over the POSIX
2370 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2371 required a bigger vector, with some working space on the end. This means that
2372 the POSIX wrapper now has to get and free some memory, and copy the results.
2373
2374 6. Added some simple autoconf support, placing the test data and the
2375 documentation in separate directories, re-organizing some of the
2376 information files, and making it build pcre-config (a GNU standard). Also added
2377 libtool support for building PCRE as a shared library, which is now the
2378 default.
2379
2380 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2381 09 are not valid octal constants. Single digits will be used for minor values
2382 less than 10.
2383
2384 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2385 existing programs that set these in the POSIX interface can use PCRE without
2386 modification.
2387
2388 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2389 return all that pcre_info() returns, plus additional data. The pcre_info()
2390 function is retained for compatibility, but is considered to be obsolete.
2391
2392 10. Added experimental recursion feature (?R) to handle one common case that
2393 Perl 5.6 will be able to do with (?p{...}).
2394
2395 11. Added support for POSIX character classes like [:alpha:], which Perl is
2396 adopting.
2397
2398
2399 Version 2.08 31-Aug-99
2400 ----------------------
2401
2402 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2403 trying to match at the startoffset position, but instead was moving forward to
2404 the next newline as if a previous match had failed.
2405
2406 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2407 and could get into a loop if a null string was matched other than at the start
2408 of the subject.
2409
2410 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2411 be distinguished at compile time, and for completeness also added PCRE_DATE.
2412
2413 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2414 in GnuWin32 environments.
2415
2416
2417 Version 2.07 29-Jul-99
2418 ----------------------
2419
2420 1. The documentation is now supplied in plain text form and HTML as well as in
2421 the form of man page sources.
2422
2423 2. C++ compilers don't like assigning (void *) values to other pointer types.
2424 In particular this affects malloc(). Although there is no problem in Standard
2425 C, I've put in casts to keep C++ compilers happy.
2426
2427 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2428 should be (const char *).
2429
2430 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2431 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2432 However, I haven't made this a standard facility. The documentation doesn't
2433 mention it, and the Makefile doesn't support it.
2434
2435 5. The Makefile now contains an "install" target, with editable destinations at
2436 the top of the file. The pcretest program is not installed.
2437
2438 6. pgrep -V now gives the PCRE version number and date.
2439
2440 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2441 causing the entire string to be ignored, instead of just the last character.
2442
2443 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2444 non-matching string, it can take a very, very long time, even for strings of
2445 quite modest length, because of the nested recursion. PCRE now does better in
2446 some of these cases. It does this by remembering the last required literal
2447 character in the pattern, and pre-searching the subject to ensure it is present
2448 before running the real match. In other words, it applies a heuristic to detect
2449 some types of certain failure quickly, and in the above example, if presented
2450 with a string that has no trailing " it gives "no match" very quickly.
2451
2452 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2453 other alternatives are tried instead.
2454
2455
2456 Version 2.06 09-Jun-99
2457 ----------------------
2458
2459 1. Change pcretest's output for amount of store used to show just the code
2460 space, because the remainder (the data block) varies in size between 32-bit and
2461 64-bit systems.
2462
2463 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2464 start matching at. This allows lookbehinds to work when searching for multiple
2465 occurrences in a string.
2466
2467 3. Added additional options to pcretest for testing multiple occurrences:
2468
2469 /+ outputs the rest of the string that follows a match
2470 /g loops for multiple occurrences, using the new startoffset argument
2471 /G loops for multiple occurrences by passing an incremented pointer
2472
2473 4. PCRE wasn't doing the "first character" optimization for patterns starting
2474 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2475 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2476 the letter 'x'. On long subject strings, this gives a significant speed-up.
2477
2478
2479 Version 2.05 21-Apr-99
2480 ----------------------
2481
2482 1. Changed the type of magic_number from int to long int so that it works
2483 properly on 16-bit systems.
2484
2485 2. Fixed a bug which caused patterns starting with .* not to work correctly
2486 when the subject string contained newline characters. PCRE was assuming
2487 anchoring for such patterns in all cases, which is not correct because .* will
2488 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2489 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2490 must be retried after every newline in the subject.
2491
2492
2493 Version 2.04 18-Feb-99
2494 ----------------------
2495
2496 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2497 computation of the store needed to hold the pattern was incorrect (too large).
2498 If such patterns were nested a few deep, this could multiply and become a real
2499 problem.
2500
2501 2. Added /M option to pcretest to show the memory requirement of a specific
2502 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2503
2504 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2505 compiled in such a way that the backtracking after subsequent failure was
2506 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2507 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2508
2509
2510 Version 2.03 02-Feb-99
2511 ----------------------
2512
2513 1. Fixed typo and small mistake in man page.
2514
2515 2. Added 4th condition (GPL supersedes if conflict) and created separate
2516 LICENCE file containing the conditions.
2517
2518 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2519 Perl, that is the internal \ allows the delimiter to be included in the
2520 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2521 the final delimiter, add \ to the end of the pattern (to test the error).
2522
2523 4. Added the convenience functions for extracting substrings after a successful
2524 match. Updated pcretest to make it able to test these functions.
2525
2526
2527 Version 2.02 14-Jan-99
2528 ----------------------
2529
2530 1. Initialized the working variables associated with each extraction so that
2531 their saving and restoring doesn't refer to uninitialized store.
2532
2533 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2534 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2535 fix the problem.
2536
2537 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2538 calls, and wasn't printing the correct value for compiling calls. Increased the
2539 default value of LOOPREPEAT, and the number of significant figures in the
2540 times.
2541
2542 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2543
2544 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2545 a building problem on Windows NT with a FAT file system.
2546
2547
2548 Version 2.01 21-Oct-98
2549 ----------------------
2550
2551 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2552 to character tables built by pcre_maketables() in the current locale. If NULL
2553 is passed, the default tables are used.
2554
2555
2556 Version 2.00 24-Sep-98
2557 ----------------------
2558
2559 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2560 it any more.
2561
2562 2. Allow quantification of (?>) groups, and make it work correctly.
2563
2564 3. The first character computation wasn't working for (?>) groups.
2565
2566 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2567 end of the subject) and add 5.005's \z, which really does match only at the
2568 very end of the subject.
2569
2570 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2571
2572 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2573 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2574 localized options. All options to pcre_study() were also removed.
2575
2576 7. Add other new features from 5.005:
2577
2578 $(?<= positive lookbehind
2579 $(?<! negative lookbehind
2580 (?imsx-imsx) added the unsetting capability
2581 such a setting is global if at outer level; local otherwise
2582 (?imsx-imsx:) non-capturing groups with option setting
2583 (?(cond)re|re) conditional pattern matching
2584
2585 A backreference to itself in a repeated group matches the previous
2586 captured string.
2587
2588 8. General tidying up of studying (both automatic and via "study")
2589 consequential on the addition of new assertions.
2590
2591 9. As in 5.005, unlimited repeated groups that could match an empty substring
2592 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2593 runtime if any iteration does actually match an empty substring.
2594
2595 10. Include the RunTest script in the distribution.
2596
2597 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2598 discrepancies, some of which were old and were also with respect to 5.004. They
2599 have now been fixed.
2600
2601
2602 Version 1.09 28-Apr-98
2603 ----------------------
2604
2605 1. A negated single character class followed by a quantifier with a minimum
2606 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2607 program crashes, or just wrong answers. This did not apply to negated classes
2608 containing more than one character, or to minima other than one.
2609
2610
2611 Version 1.08 27-Mar-98
2612 ----------------------
2613
2614 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2615
2616 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2617 latter must appear before anything that relies on it in the pattern.
2618
2619
2620 Version 1.07 16-Feb-98
2621 ----------------------
2622
2623 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2624 repeat of a potentially empty string).
2625
2626
2627 Version 1.06 23-Jan-98
2628 ----------------------
2629
2630 1. Added Markus Oberhumer's little patches for C++.
2631
2632 2. Literal strings longer than 255 characters were broken.
2633
2634
2635 Version 1.05 23-Dec-97
2636 ----------------------
2637
2638 1. Negated character classes containing more than one character were failing if
2639 PCRE_CASELESS was set at run time.
2640
2641
2642 Version 1.04 19-Dec-97
2643 ----------------------
2644
2645 1. Corrected the man page, where some "const" qualifiers had been omitted.
2646
2647 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2648 input syntax.
2649
2650 3. Fixed memory leak which occurred when a regex with back references was
2651 matched with an offsets vector that wasn't big enough. The temporary memory
2652 that is used in this case wasn't being freed if the match failed.
2653
2654 4. Tidied pcretest to ensure it frees memory that it gets.
2655
2656 5. Temporary memory was being obtained in the case where the passed offsets
2657 vector was exactly big enough.
2658
2659 6. Corrected definition of offsetof() from change 5 below.
2660
2661 7. I had screwed up change 6 below and broken the rules for the use of
2662 setjmp(). Now fixed.
2663
2664
2665 Version 1.03 18-Dec-97
2666 ----------------------
2667
2668 1. A erroneous regex with a missing opening parenthesis was correctly
2669 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2670 on some systems.
2671
2672 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2673 it was reported that one broken compiler failed on the former because "code" is
2674 also an independent variable.
2675
2676 3. The erroneous regex a[]b caused an array overrun reference.
2677
2678 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2679 fail on data ending with that character. (It was going on too far, and checking
2680 the next character, typically a binary zero.) This was specific to the
2681 optimized code for single-character negative classes.
2682
2683 5. Added a contributed patch from the TIN world which does the following:
2684
2685 + Add an undef for memmove, in case the the system defines a macro for it.
2686
2687 + Add a definition of offsetof(), in case there isn't one. (I don't know
2688 the reason behind this - offsetof() is part of the ANSI standard - but
2689 it does no harm).
2690
2691 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2692 most of the places where whitespace preceded '#'. I have given up and
2693 allowed the remaining 2 cases to be at the margin.
2694
2695 + Rename some variables in pcre to eliminate shadowing. This seems very
2696 pedantic, but does no harm, of course.
2697
2698 6. Moved the call to setjmp() into its own function, to get rid of warnings
2699 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2700
2701 7. Constructs such as \d{8,} were compiling into the equivalent of
2702 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2703 outcome, but in this particular case used more store than had been allocated,
2704 which caused the bug to be discovered because it threw up an internal error.
2705
2706 8. The debugging code in both pcre and pcretest for outputting the compiled
2707 form of a regex was going wrong in the case of back references followed by
2708 curly-bracketed repeats.
2709
2710
2711 Version 1.02 12-Dec-97
2712 ----------------------
2713
2714 1. Typos in pcre.3 and comments in the source fixed.
2715
2716 2. Applied a contributed patch to get rid of places where it used to remove
2717 'const' from variables, and fixed some signed/unsigned and uninitialized
2718 variable warnings.
2719
2720 3. Added the "runtest" target to Makefile.
2721
2722 4. Set default compiler flag to -O2 rather than just -O.
2723
2724
2725 Version 1.01 19-Nov-97
2726 ----------------------
2727
2728 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2729 like /([ab]*)*/, that is, for classes with more than one character in them.
2730
2731 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2732 as /((?>a*))*/ (a PCRE_EXTRA facility).
2733
2734
2735 Version 1.00 18-Nov-97
2736 ----------------------
2737
2738 1. Added compile-time macros to support systems such as SunOS4 which don't have
2739 memmove() or strerror() but have other things that can be used instead.
2740
2741 2. Arranged that "make clean" removes the executables.
2742
2743
2744 Version 0.99 27-Oct-97
2745 ----------------------
2746
2747 1. Fixed bug in code for optimizing classes with only one character. It was
2748 initializing a 32-byte map regardless, which could cause it to run off the end
2749 of the memory it had got.
2750
2751 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2752
2753
2754 Version 0.98 22-Oct-97
2755 ----------------------
2756
2757 1. Fixed bug in code for handling temporary memory usage when there are more
2758 back references than supplied space in the ovector. This could cause segfaults.
2759
2760
2761 Version 0.97 21-Oct-97
2762 ----------------------
2763
2764 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2765
2766 2. Optimized negated single characters not to use a bit map.
2767
2768 3. Brought error texts together as macro definitions; clarified some of them;
2769 fixed one that was wrong - it said "range out of order" when it meant "invalid
2770 escape sequence".
2771
2772 4. Changed some char * arguments to const char *.
2773
2774 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2775
2776 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2777 pcretest.
2778
2779
2780 Version 0.96 16-Oct-97
2781 ----------------------
2782
2783 1. Added a simple "pgrep" utility to the distribution.
2784
2785 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2786 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2787 where "ddd" means "one or more decimal digits".
2788
2789 3. Fixed serious bug. If a pattern had a back reference, but the call to
2790 pcre_exec() didn't supply a large enough ovector to record the related
2791 identifying subpattern, the match always failed. PCRE now remembers the number
2792 of the largest back reference, and gets some temporary memory in which to save
2793 the offsets during matching if necessary, in order to ensure that
2794 backreferences always work.
2795
2796 4. Increased the compatibility with Perl in a number of ways:
2797
2798 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2799 to request this handling. The option can be set at compile or exec time.
2800
2801 (b) $ matches before a terminating newline by default; an option
2802 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2803 mode). The option can be set at compile or exec time.
2804
2805 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2806 the same as Perl's. If the decimal number it represents is less than 10
2807 or there aren't that many previous left capturing parentheses, an octal
2808 escape is read. Inside a character class, it's always an octal escape,
2809 even if it is a single digit.
2810
2811 (d) An escaped but undefined alphabetic character is taken as a literal,
2812 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2813 escapes.
2814
2815 (e) {0} is now permitted. (The previous item is removed from the compiled
2816 pattern).
2817
2818 5. Changed all the names of code files so that the basic parts are no longer
2819 than 10 characters, and abolished the teeny "globals.c" file.
2820
2821 6. Changed the handling of character classes; they are now done with a 32-byte
2822 bit map always.
2823
2824 7. Added the -d and /D options to pcretest to make it possible to look at the
2825 internals of compilation without having to recompile pcre.
2826
2827
2828 Version 0.95 23-Sep-97
2829 ----------------------
2830
2831 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2832 \x20 at the start of a run of normal characters. These were being treated as
2833 real characters, instead of the source characters being re-checked.
2834
2835
2836 Version 0.94 18-Sep-97
2837 ----------------------
2838
2839 1. The functions are now thread-safe, with the caveat that the global variables
2840 containing pointers to malloc() and free() or alternative functions are the
2841 same for all threads.
2842
2843 2. Get pcre_study() to generate a bitmap of initial characters for non-
2844 anchored patterns when this is possible, and use it if passed to pcre_exec().
2845
2846
2847 Version 0.93 15-Sep-97
2848 ----------------------
2849
2850 1. /(b)|(:+)/ was computing an incorrect first character.
2851
2852 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2853 but not actually doing anything yet.
2854
2855 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2856 as Perl does (e.g. [-az] or [az-]).
2857
2858 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2859 all possible positions.
2860
2861 5. Split up into different modules to avoid including unneeded functions in a
2862 compiled binary. However, compile and exec are still in one module. The "study"
2863 function is split off.
2864
2865 6. The character tables are now in a separate module whose source is generated
2866 by an auxiliary program - but can then be edited by hand if required. There are
2867 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2868 toupper() in the code.
2869
2870 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2871 make them global. Abolish the function for setting them, as the caller can now
2872 set them directly.
2873
2874
2875 Version 0.92 11-Sep-97
2876 ----------------------
2877
2878 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2879 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2880
2881 2. Caseless matching was not working in character classes if the characters in
2882 the pattern were in upper case.
2883
2884 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2885
2886 4. Make PCRE_ANCHORED public and accept as a compile option.
2887
2888 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
2889 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
2890 pass them.
2891
2892 6. Give an error if bad option bits passed at compile or run time.
2893
2894 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
2895 pcretest to cause it to pass that flag.
2896
2897 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
2898 options, and the first character, if set.
2899
2900 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
2901
2902
2903 Version 0.91 10-Sep-97
2904 ----------------------
2905
2906 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
2907 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
2908
2909 2. PCRE was looping on encountering an indefinitely repeated back reference to
2910 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
2911 Perl does - treats the match as successful.
2912
2913 ****

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