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Revision 264 - (show annotations) (download)
Tue Nov 13 11:07:16 2007 UTC (6 years, 5 months ago) by ph10
File size: 142292 byte(s)
Fix [\S] etc. bug in UTF-8 mode with characters > 255.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.5 12-Nov-07
5 ---------------------
6
7 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
8 values in parens when parsing an RE using the C++ wrapper."
9
10 2. Negative specials like \S did not work in character classes in UTF-8 mode.
11 Characters greater than 255 were excluded from the class instead of being
12 included.
13
14
15 Version 7.4 21-Sep-07
16 ---------------------
17
18 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
19 means that a class such as [\s] counted as "explicit reference to CR or
20 LF". That isn't really right - the whole point of the change was to try to
21 help when there was an actual mention of one of the two characters. So now
22 the change happens only if \r or \n (or a literal CR or LF) character is
23 encountered.
24
25 2. The 32-bit options word was also used for 6 internal flags, but the numbers
26 of both had grown to the point where there were only 3 bits left.
27 Fortunately, there was spare space in the data structure, and so I have
28 moved the internal flags into a new 16-bit field to free up more option
29 bits.
30
31 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
32 but did not set the internal JCHANGED flag - either of these is enough to
33 control the way the "get" function works - but the PCRE_INFO_JCHANGED
34 facility is supposed to tell if (?J) was ever used, so now (?J) at the
35 start sets both bits.
36
37 4. Added options (at build time, compile time, exec time) to change \R from
38 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
39
40 5. doc/pcresyntax.html was missing from the distribution.
41
42 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
43 compatibility, even though it is no longer used.
44
45 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
46 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
47 windows.h file is present (where different names are used). [This was
48 reversed later after testing - see 16 below.]
49
50 8. Changed all #include <config.h> to #include "config.h". There were also
51 some further <pcre.h> cases that I changed to "pcre.h".
52
53 9. When pcregrep was used with the --colour option, it missed the line ending
54 sequence off the lines that it output.
55
56 10. It was pointed out to me that arrays of string pointers cause lots of
57 relocations when a shared library is dynamically loaded. A technique of
58 using a single long string with a table of offsets can drastically reduce
59 these. I have refactored PCRE in four places to do this. The result is
60 dramatic:
61
62 Originally: 290
63 After changing UCP table: 187
64 After changing error message table: 43
65 After changing table of "verbs" 36
66 After changing table of Posix names 22
67
68 Thanks to the folks working on Gregex for glib for this insight.
69
70 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
71 unicode-properties was also set.
72
73 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
74
75 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
76 checked only for CRLF.
77
78 14. Added casts to pcretest.c to avoid compiler warnings.
79
80 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
81
82 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
83 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
84 entirely. This removes changes made in 7 above.
85
86 17. The CMake files have been updated, and there is now more information about
87 building with CMake in the NON-UNIX-USE document.
88
89
90 Version 7.3 28-Aug-07
91 ---------------------
92
93 1. In the rejigging of the build system that eventually resulted in 7.1, the
94 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
95 brackets there is not right, since it causes compilers to look for an
96 installed pcre.h, not the version that is in the source that is being
97 compiled (which of course may be different). I have changed it back to:
98
99 #include "pcre.h"
100
101 I have a vague recollection that the change was concerned with compiling in
102 different directories, but in the new build system, that is taken care of
103 by the VPATH setting the Makefile.
104
105 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
106 when the subject happened to end in the byte 0x85 (e.g. if the last
107 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
108 characters but of course it shouldn't be taken as a newline when it is part
109 of another character. The bug was that, for an unlimited repeat of . in
110 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
111 characters when looking for a newline.
112
113 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
114
115 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
116 in debug output.
117
118 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
119 long printing in the pcrecpp unittest when running under MinGW.
120
121 6. ESC_K was left out of the EBCDIC table.
122
123 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
124 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
125 limit also applies to "virtual nesting" when a pattern is recursive, and in
126 this case 1000 isn't so big. I have been able to remove this limit at the
127 expense of backing off one optimization in certain circumstances. Normally,
128 when pcre_exec() would call its internal match() function recursively and
129 immediately return the result unconditionally, it uses a "tail recursion"
130 feature to save stack. However, when a subpattern that can match an empty
131 string has an unlimited repetition quantifier, it no longer makes this
132 optimization. That gives it a stack frame in which to save the data for
133 checking that an empty string has been matched. Previously this was taken
134 from the 1000-entry workspace that had been reserved. So now there is no
135 explicit limit, but more stack is used.
136
137 8. Applied Daniel's patches to solve problems with the import/export magic
138 syntax that is required for Windows, and which was going wrong for the
139 pcreposix and pcrecpp parts of the library. These were overlooked when this
140 problem was solved for the main library.
141
142 9. There were some crude static tests to avoid integer overflow when computing
143 the size of patterns that contain repeated groups with explicit upper
144 limits. As the maximum quantifier is 65535, the maximum group length was
145 set at 30,000 so that the product of these two numbers did not overflow a
146 32-bit integer. However, it turns out that people want to use groups that
147 are longer than 30,000 bytes (though not repeat them that many times).
148 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
149 made it possible to implement the integer overflow checks in a much more
150 dynamic way, which I have now done. The artificial limitation on group
151 length has been removed - we now have only the limit on the total length of
152 the compiled pattern, which depends on the LINK_SIZE setting.
153
154 10. Fixed a bug in the documentation for get/copy named substring when
155 duplicate names are permitted. If none of the named substrings are set, the
156 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
157 empty string.
158
159 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
160 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
161 because the ] is interpreted as the first data character and the
162 terminating ] is not found. PCRE has been made compatible with Perl in this
163 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
164 cause memory overwriting.
165
166 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
167 string has been matched (to stop an infinite loop). It was not recognizing
168 a conditional subpattern that could match an empty string if that
169 subpattern was within another subpattern. For example, it looped when
170 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
171 condition was not nested. This bug has been fixed.
172
173 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
174 past the start of the subject in the presence of bytes with the top bit
175 set, for example "\x8aBCD".
176
177 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
178 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
179
180 14. Optimized (?!) to (*FAIL).
181
182 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
183 This restricts code points to be within the range 0 to 0x10FFFF, excluding
184 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
185 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
186 does: it's just the validity check that is more restrictive.
187
188 16. Inserted checks for integer overflows during escape sequence (backslash)
189 processing, and also fixed erroneous offset values for syntax errors during
190 backslash processing.
191
192 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
193 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
194
195 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
196 caused an overrun.
197
198 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
199 something other than just ASCII characters) inside a group that had an
200 unlimited repeat caused a loop at compile time (while checking to see
201 whether the group could match an empty string).
202
203 20. Debugging a pattern containing \p or \P could cause a crash. For example,
204 [\P{Any}] did so. (Error in the code for printing property names.)
205
206 21. An orphan \E inside a character class could cause a crash.
207
208 22. A repeated capturing bracket such as (A)? could cause a wild memory
209 reference during compilation.
210
211 23. There are several functions in pcre_compile() that scan along a compiled
212 expression for various reasons (e.g. to see if it's fixed length for look
213 behind). There were bugs in these functions when a repeated \p or \P was
214 present in the pattern. These operators have additional parameters compared
215 with \d, etc, and these were not being taken into account when moving along
216 the compiled data. Specifically:
217
218 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
219 length.
220
221 (b) An item such as \pL+ within a repeated group could cause crashes or
222 loops.
223
224 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
225 "reference to non-existent subpattern" error.
226
227 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
228
229 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
230 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
231
232 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
233
234 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
235 character were causing crashes (broken optimization).
236
237 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
238 \p or \P) caused a compile-time loop.
239
240 28. More problems have arisen in unanchored patterns when CRLF is a valid line
241 break. For example, the unstudied pattern [\r\n]A does not match the string
242 "\r\nA" because change 7.0/46 below moves the current point on by two
243 characters after failing to match at the start. However, the pattern \nA
244 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
245 the same is true. There doesn't seem any very clean way out of this, but
246 what I have chosen to do makes the common cases work: PCRE now takes note
247 of whether there can be an explicit match for \r or \n anywhere in the
248 pattern, and if so, 7.0/46 no longer applies. As part of this change,
249 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
250 pattern has explicit CR or LF references.
251
252 29. Added (*CR) etc for changing newline setting at start of pattern.
253
254
255 Version 7.2 19-Jun-07
256 ---------------------
257
258 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
259 which is apparently normally available under Windows.
260
261 2. Re-jig the pcregrep tests with different newline settings in an attempt
262 to make them independent of the local environment's newline setting.
263
264 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
265
266 4. Some of the "internals" tests were previously cut out when the link size
267 was not 2, because the output contained actual offsets. The recent new
268 "Z" feature of pcretest means that these can be cut out, making the tests
269 usable with all link sizes.
270
271 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
272 stack recursion. This gives a massive performance boost under BSD, but just
273 a small improvement under Linux. However, it saves one field in the frame
274 in all cases.
275
276 6. Added more features from the forthcoming Perl 5.10:
277
278 (a) (?-n) (where n is a string of digits) is a relative subroutine or
279 recursion call. It refers to the nth most recently opened parentheses.
280
281 (b) (?+n) is also a relative subroutine call; it refers to the nth next
282 to be opened parentheses.
283
284 (c) Conditions that refer to capturing parentheses can be specified
285 relatively, for example, (?(-2)... or (?(+3)...
286
287 (d) \K resets the start of the current match so that everything before
288 is not part of it.
289
290 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
291
292 (f) \g{name} is another synonym - part of Perl 5.10's unification of
293 reference syntax.
294
295 (g) (?| introduces a group in which the numbering of parentheses in each
296 alternative starts with the same number.
297
298 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
299
300 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
301 PCRE_INFO_JCHANGED.
302
303 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
304 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
305 for detecting groups that can match an empty string.
306
307 9. A pattern with a very large number of alternatives (more than several
308 hundred) was running out of internal workspace during the pre-compile
309 phase, where pcre_compile() figures out how much memory will be needed. A
310 bit of new cunning has reduced the workspace needed for groups with
311 alternatives. The 1000-alternative test pattern now uses 12 bytes of
312 workspace instead of running out of the 4096 that are available.
313
314 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
315
316 11. Applied patch from Google to remove an optimization that didn't quite work.
317 The report of the bug said:
318
319 pcrecpp::RE("a*").FullMatch("aaa") matches, while
320 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
321 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
322
323 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
324 it matched the wrong number of bytes.
325
326
327 Version 7.1 24-Apr-07
328 ---------------------
329
330 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
331 that is more "standard", making use of automake and other Autotools. There
332 is some re-arrangement of the files and adjustment of comments consequent
333 on this.
334
335 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
336 for recursive directory scanning broke on some systems because the files
337 are not scanned in any specific order and on different systems the order
338 was different. A call to "sort" has been inserted into RunGrepTest for the
339 approprate test as a short-term fix. In the longer term there may be an
340 alternative.
341
342 3. I had an email from Eric Raymond about problems translating some of PCRE's
343 man pages to HTML (despite the fact that I distribute HTML pages, some
344 people do their own conversions for various reasons). The problems
345 concerned the use of low-level troff macros .br and .in. I have therefore
346 removed all such uses from the man pages (some were redundant, some could
347 be replaced by .nf/.fi pairs). The 132html script that I use to generate
348 HTML has been updated to handle .nf/.fi and to complain if it encounters
349 .br or .in.
350
351 4. Updated comments in configure.ac that get placed in config.h.in and also
352 arranged for config.h to be included in the distribution, with the name
353 config.h.generic, for the benefit of those who have to compile without
354 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
355
356 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
357 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
358 makevp.bat for the current PCRE, using the additional files
359 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
360
361 6. A Windows user reported a minor discrepancy with test 2, which turned out
362 to be caused by a trailing space on an input line that had got lost in his
363 copy. The trailing space was an accident, so I've just removed it.
364
365 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
366 that is needed.
367
368 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
369 as "const" (a) because they are and (b) because it helps the PHP
370 maintainers who have recently made a script to detect big data structures
371 in the php code that should be moved to the .rodata section. I remembered
372 to update Builducptable as well, so it won't revert if ucptable.h is ever
373 re-created.
374
375 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
376 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
377 order to be able to cut out the UTF-8 tables in the latter when UTF-8
378 support is not required. This saves 1.5-2K of code, which is important in
379 some applications.
380
381 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
382 so as not to refer to the tables, even though these functions will never be
383 called when UTF-8 support is disabled. Otherwise there are problems with a
384 shared library.
385
386 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
387
388 (a) It was defining its arguments as char * instead of void *.
389
390 (b) It was assuming that all moves were upwards in memory; this was true
391 a long time ago when I wrote it, but is no longer the case.
392
393 The emulated memove() is provided for those environments that have neither
394 memmove() nor bcopy(). I didn't think anyone used it these days, but that
395 is clearly not the case, as these two bugs were recently reported.
396
397 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
398 and Detrail to create the HTML documentation, the .txt form of the man
399 pages, and it removes trailing spaces from listed files. It also creates
400 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
401 case, it wraps all the #defines with #ifndefs. This script should be run
402 before "make dist".
403
404 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
405 with Unicode property support.
406
407 (a) For a maximizing quantifier, if the two different cases of the
408 character were of different lengths in their UTF-8 codings (there are
409 some cases like this - I found 11), and the matching function had to
410 back up over a mixture of the two cases, it incorrectly assumed they
411 were both the same length.
412
413 (b) When PCRE was configured to use the heap rather than the stack for
414 recursion during matching, it was not correctly preserving the data for
415 the other case of a UTF-8 character when checking ahead for a match
416 while processing a minimizing repeat. If the check also involved
417 matching a wide character, but failed, corruption could cause an
418 erroneous result when trying to check for a repeat of the original
419 character.
420
421 13. Some tidying changes to the testing mechanism:
422
423 (a) The RunTest script now detects the internal link size and whether there
424 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
425 values substituted by "configure". (The RunGrepTest script already did
426 this for UTF-8.) The configure.ac script no longer substitutes the
427 relevant variables.
428
429 (b) The debugging options /B and /D in pcretest show the compiled bytecode
430 with length and offset values. This means that the output is different
431 for different internal link sizes. Test 2 is skipped for link sizes
432 other than 2 because of this, bypassing the problem. Unfortunately,
433 there was also a test in test 3 (the locale tests) that used /B and
434 failed for link sizes other than 2. Rather than cut the whole test out,
435 I have added a new /Z option to pcretest that replaces the length and
436 offset values with spaces. This is now used to make test 3 independent
437 of link size. (Test 2 will be tidied up later.)
438
439 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
440 segmentation fault instead of returning the appropriate error message.
441
442 15. In multiline mode when the newline sequence was set to "any", the pattern
443 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
444 This doesn't seem right; it now treats the CRLF combination as the line
445 ending, and so does not match in that case. It's only a pattern such as ^$
446 that would hit this one: something like ^ABC$ would have failed after \r
447 and then tried again after \r\n.
448
449 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
450 in an attempt to make files that differ only in their line terminators
451 compare equal. This works on Linux.
452
453 17. Under certain error circumstances pcregrep might try to free random memory
454 as it exited. This is now fixed, thanks to valgrind.
455
456 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
457 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
458 was because its rules for how to advance for /g after matching an empty
459 string at the end of a line did not allow for this case. They now check for
460 it specially.
461
462 20. pcretest is supposed to handle patterns and data of any length, by
463 extending its buffers when necessary. It was getting this wrong when the
464 buffer for a data line had to be extended.
465
466 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
467 CRLF as a newline sequence.
468
469 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
470 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
471 I have nevertheless tidied it up.
472
473 23. Added some casts to kill warnings from HP-UX ia64 compiler.
474
475 24. Added a man page for pcre-config.
476
477
478 Version 7.0 19-Dec-06
479 ---------------------
480
481 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
482 moving to gcc 4.1.1.
483
484 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
485 sys/time.h, which is documented as needed for this function. It doesn't
486 seem to matter on Linux, but it showed up on some releases of OS X.
487
488 3. It seems that there are systems where bytes whose values are greater than
489 127 match isprint() in the "C" locale. The "C" locale should be the
490 default when a C program starts up. In most systems, only ASCII printing
491 characters match isprint(). This difference caused the output from pcretest
492 to vary, making some of the tests fail. I have changed pcretest so that:
493
494 (a) When it is outputting text in the compiled version of a pattern, bytes
495 other than 32-126 are always shown as hex escapes.
496
497 (b) When it is outputting text that is a matched part of a subject string,
498 it does the same, unless a different locale has been set for the match
499 (using the /L modifier). In this case, it uses isprint() to decide.
500
501 4. Fixed a major bug that caused incorrect computation of the amount of memory
502 required for a compiled pattern when options that changed within the
503 pattern affected the logic of the preliminary scan that determines the
504 length. The relevant options are -x, and -i in UTF-8 mode. The result was
505 that the computed length was too small. The symptoms of this bug were
506 either the PCRE error "internal error: code overflow" from pcre_compile(),
507 or a glibc crash with a message such as "pcretest: free(): invalid next
508 size (fast)". Examples of patterns that provoked this bug (shown in
509 pcretest format) are:
510
511 /(?-x: )/x
512 /(?x)(?-x: \s*#\s*)/
513 /((?i)[\x{c0}])/8
514 /(?i:[\x{c0}])/8
515
516 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
517 is now done differently.
518
519 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
520 wrapper classes; (b) implement a new function in the C++ scanner that is
521 more efficient than the old way of doing things because it avoids levels of
522 recursion in the regex matching; (c) add a paragraph to the documentation
523 for the FullMatch() function.
524
525 6. The escape sequence \n was being treated as whatever was defined as
526 "newline". Not only was this contrary to the documentation, which states
527 that \n is character 10 (hex 0A), but it also went horribly wrong when
528 "newline" was defined as CRLF. This has been fixed.
529
530 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
531 was being set to -1 for the "end of line" case (supposedly a value that no
532 character can have). Though this value is never used (the check for end of
533 line is "zero bytes in current character"), it caused compiler complaints.
534 I've changed it to 0xffffffff.
535
536 8. In pcre_version.c, the version string was being built by a sequence of
537 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
538 string (as it is for production releases) called a macro with an empty
539 argument. The C standard says the result of this is undefined. The gcc
540 compiler treats it as an empty string (which was what was wanted) but it is
541 reported that Visual C gives an error. The source has been hacked around to
542 avoid this problem.
543
544 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
545 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
546 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
547 of them did).
548
549 10. Originally, pcretest opened its input and output without "b"; then I was
550 told that "b" was needed in some environments, so it was added for release
551 5.0 to both the input and output. (It makes no difference on Unix-like
552 systems.) Later I was told that it is wrong for the input on Windows. I've
553 now abstracted the modes into two macros, to make it easier to fiddle with
554 them, and removed "b" from the input mode under Windows.
555
556 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
557
558 12. Added -help and --help to pcretest as an official way of being reminded
559 of the options.
560
561 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
562 and pcrecpp.cc because they annoy compilers at high warning levels.
563
564 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
565
566 15. Fixed an occurrence of == in configure.ac that should have been = (shell
567 scripts are not C programs :-) and which was not noticed because it works
568 on Linux.
569
570 16. pcretest is supposed to handle any length of pattern and data line (as one
571 line or as a continued sequence of lines) by extending its input buffer if
572 necessary. This feature was broken for very long pattern lines, leading to
573 a string of junk being passed to pcre_compile() if the pattern was longer
574 than about 50K.
575
576 17. I have done a major re-factoring of the way pcre_compile() computes the
577 amount of memory needed for a compiled pattern. Previously, there was code
578 that made a preliminary scan of the pattern in order to do this. That was
579 OK when PCRE was new, but as the facilities have expanded, it has become
580 harder and harder to keep it in step with the real compile phase, and there
581 have been a number of bugs (see for example, 4 above). I have now found a
582 cunning way of running the real compile function in a "fake" mode that
583 enables it to compute how much memory it would need, while actually only
584 ever using a few hundred bytes of working memory and without too many
585 tests of the mode. This should make future maintenance and development
586 easier. A side effect of this work is that the limit of 200 on the nesting
587 depth of parentheses has been removed (though this was never a serious
588 limitation, I suspect). However, there is a downside: pcre_compile() now
589 runs more slowly than before (30% or more, depending on the pattern). I
590 hope this isn't a big issue. There is no effect on runtime performance.
591
592 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
593 newline (only possible for the last line of a file) and it was a
594 pattern that set a locale (followed by /Lsomething), pcretest crashed.
595
596 19. Added additional timing features to pcretest. (1) The -tm option now times
597 matching only, not compiling. (2) Both -t and -tm can be followed, as a
598 separate command line item, by a number that specifies the number of
599 repeats to use when timing. The default is 50000; this gives better
600 precision, but takes uncomfortably long for very large patterns.
601
602 20. Extended pcre_study() to be more clever in cases where a branch of a
603 subpattern has no definite first character. For example, (a*|b*)[cd] would
604 previously give no result from pcre_study(). Now it recognizes that the
605 first character must be a, b, c, or d.
606
607 21. There was an incorrect error "recursive call could loop indefinitely" if
608 a subpattern (or the entire pattern) that was being tested for matching an
609 empty string contained only one non-empty item after a nested subpattern.
610 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
611 incorrectly, because the \d was being skipped in the check.
612
613 22. The pcretest program now has a new pattern option /B and a command line
614 option -b, which is equivalent to adding /B to every pattern. This causes
615 it to show the compiled bytecode, without the additional information that
616 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
617 is the same as /B/I).
618
619 23. A new optimization is now able automatically to treat some sequences such
620 as a*b as a*+b. More specifically, if something simple (such as a character
621 or a simple class like \d) has an unlimited quantifier, and is followed by
622 something that cannot possibly match the quantified thing, the quantifier
623 is automatically "possessified".
624
625 24. A recursive reference to a subpattern whose number was greater than 39
626 went wrong under certain circumstances in UTF-8 mode. This bug could also
627 have affected the operation of pcre_study().
628
629 25. Realized that a little bit of performance could be had by replacing
630 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
631
632 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
633
634 27. Possessive quantifiers such as a++ were previously implemented by turning
635 them into atomic groups such as ($>a+). Now they have their own opcodes,
636 which improves performance. This includes the automatically created ones
637 from 23 above.
638
639 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
640 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
641 the first matched character to be a colon. This applied both to named and
642 numbered groups.
643
644 29. The ucpinternal.h header file was missing its idempotency #ifdef.
645
646 30. I was sent a "project" file called libpcre.a.dev which I understand makes
647 building PCRE on Windows easier, so I have included it in the distribution.
648
649 31. There is now a check in pcretest against a ridiculously large number being
650 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
651 loop, the loop is abandoned.
652
653 32. Forward references to subpatterns in conditions such as (?(2)...) where
654 subpattern 2 is defined later cause pcre_compile() to search forwards in
655 the pattern for the relevant set of parentheses. This search went wrong
656 when there were unescaped parentheses in a character class, parentheses
657 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
658
659 33. "Subroutine" calls and backreferences were previously restricted to
660 referencing subpatterns earlier in the regex. This restriction has now
661 been removed.
662
663 34. Added a number of extra features that are going to be in Perl 5.10. On the
664 whole, these are just syntactic alternatives for features that PCRE had
665 previously implemented using the Python syntax or my own invention. The
666 other formats are all retained for compatibility.
667
668 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
669 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
670 also .NET compatible.
671
672 (b) A recursion or subroutine call to a named group can now be defined as
673 (?&name) as well as (?P>name).
674
675 (c) A backreference to a named group can now be defined as \k<name> or
676 \k'name' as well as (?P=name). The new forms, as well as being in Perl
677 5.10, are also .NET compatible.
678
679 (d) A conditional reference to a named group can now use the syntax
680 (?(<name>) or (?('name') as well as (?(name).
681
682 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
683 groups (named and numbered) that are never evaluated inline, but can be
684 called as "subroutines" from elsewhere. In effect, the DEFINE condition
685 is always false. There may be only one alternative in such a group.
686
687 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
688 as the simple (?(R). The condition is true only if the most recent
689 recursion is that of the given number or name. It does not search out
690 through the entire recursion stack.
691
692 (g) The escape \gN or \g{N} has been added, where N is a positive or
693 negative number, specifying an absolute or relative reference.
694
695 35. Tidied to get rid of some further signed/unsigned compiler warnings and
696 some "unreachable code" warnings.
697
698 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
699 things, this adds five new scripts.
700
701 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
702 There were also incompatibilities regarding the handling of \Q..\E inside
703 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
704 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
705
706 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
707 matches an empty string, and forcibly breaks the loop. There were bugs in
708 this code in non-simple cases. For a pattern such as ^(a()*)* matched
709 against aaaa the result was just "a" rather than "aaaa", for example. Two
710 separate and independent bugs (that affected different cases) have been
711 fixed.
712
713 39. Refactored the code to abolish the use of different opcodes for small
714 capturing bracket numbers. This is a tidy that I avoided doing when I
715 removed the limit on the number of capturing brackets for 3.5 back in 2001.
716 The new approach is not only tidier, it makes it possible to reduce the
717 memory needed to fix the previous bug (38).
718
719 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
720 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
721 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
722 mode.
723
724 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
725 report.
726
727 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
728 copy construction and assignment in the C++ wrapper.
729
730 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
731 couple of bugs that could have given wrong results in the "--newline=crlf"
732 case.
733
734 44. Added a number of casts and did some reorganization of signed/unsigned int
735 variables following suggestions from Dair Grant. Also renamed the variable
736 "this" as "item" because it is a C++ keyword.
737
738 45. Arranged for dftables to add
739
740 #include "pcre_internal.h"
741
742 to pcre_chartables.c because without it, gcc 4.x may remove the array
743 definition from the final binary if PCRE is built into a static library and
744 dead code stripping is activated.
745
746 46. For an unanchored pattern, if a match attempt fails at the start of a
747 newline sequence, and the newline setting is CRLF or ANY, and the next two
748 characters are CRLF, advance by two characters instead of one.
749
750
751 Version 6.7 04-Jul-06
752 ---------------------
753
754 1. In order to handle tests when input lines are enormously long, pcretest has
755 been re-factored so that it automatically extends its buffers when
756 necessary. The code is crude, but this _is_ just a test program. The
757 default size has been increased from 32K to 50K.
758
759 2. The code in pcre_study() was using the value of the re argument before
760 testing it for NULL. (Of course, in any sensible call of the function, it
761 won't be NULL.)
762
763 3. The memmove() emulation function in pcre_internal.h, which is used on
764 systems that lack both memmove() and bcopy() - that is, hardly ever -
765 was missing a "static" storage class specifier.
766
767 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
768 containing an extended class (one that cannot be represented by a bitmap
769 because it contains high-valued characters or Unicode property items, e.g.
770 [\pZ]). Almost always one would set UTF-8 mode when processing such a
771 pattern, but PCRE should not loop if you do not (it no longer does).
772 [Detail: two cases were found: (a) a repeated subpattern containing an
773 extended class; (b) a recursive reference to a subpattern that followed a
774 previous extended class. It wasn't skipping over the extended class
775 correctly when UTF-8 mode was not set.]
776
777 5. A negated single-character class was not being recognized as fixed-length
778 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
779 compile error "lookbehind assertion is not fixed length".
780
781 6. The RunPerlTest auxiliary script was showing an unexpected difference
782 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
783 write a Perl script that can interpret lines of an input file either as
784 byte characters or as UTF-8, which is what "perltest" was being required to
785 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
786 can't do is switch easily at run time between having the "use utf8;" pragma
787 or not. In the end, I fudged it by using the RunPerlTest script to insert
788 "use utf8;" explicitly for the UTF-8 tests.
789
790 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
791 the end of the subject string, contrary to the documentation and to what
792 Perl does. This was true of both matching functions. Now it matches only at
793 the start of the subject and immediately after *internal* newlines.
794
795 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
796 a pointer to an int instead of a pointer to an unsigned long int. This
797 caused problems on 64-bit systems.
798
799 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
800 instance of the 'standard' template library not being so standard".
801
802 10. There was no check on the number of named subpatterns nor the maximum
803 length of a subpattern name. The product of these values is used to compute
804 the size of the memory block for a compiled pattern. By supplying a very
805 long subpattern name and a large number of named subpatterns, the size
806 computation could be caused to overflow. This is now prevented by limiting
807 the length of names to 32 characters, and the number of named subpatterns
808 to 10,000.
809
810 11. Subpatterns that are repeated with specific counts have to be replicated in
811 the compiled pattern. The size of memory for this was computed from the
812 length of the subpattern and the repeat count. The latter is limited to
813 65535, but there was no limit on the former, meaning that integer overflow
814 could in principle occur. The compiled length of a repeated subpattern is
815 now limited to 30,000 bytes in order to prevent this.
816
817 12. Added the optional facility to have named substrings with the same name.
818
819 13. Added the ability to use a named substring as a condition, using the
820 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
821 are numbers (not recommended). Forward references are permitted.
822
823 14. Added forward references in named backreferences (if you see what I mean).
824
825 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
826 pattern could run off the end of the subject. For example, the pattern
827 "(?s)(.{1,5})"8 did this with the subject "ab".
828
829 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
830 PCRE_CASELESS was set when matching characters that were quantified with ?
831 or *.
832
833 17. A character class other than a single negated character that had a minimum
834 but no maximum quantifier - for example [ab]{6,} - was not handled
835 correctly by pce_dfa_exec(). It would match only one character.
836
837 18. A valid (though odd) pattern that looked like a POSIX character
838 class but used an invalid character after [ (for example [[,abc,]]) caused
839 pcre_compile() to give the error "Failed: internal error: code overflow" or
840 in some cases to crash with a glibc free() error. This could even happen if
841 the pattern terminated after [[ but there just happened to be a sequence of
842 letters, a binary zero, and a closing ] in the memory that followed.
843
844 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
845 over the years. Originally (before any Unicode support), just the bottom 8
846 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
847 output from "man perlunicode" includes this:
848
849 The regular expression compiler produces polymorphic opcodes. That
850 is, the pattern adapts to the data and automatically switches to
851 the Unicode character scheme when presented with Unicode data--or
852 instead uses a traditional byte scheme when presented with byte
853 data.
854
855 Sadly, a wide octal escape does not cause a switch, and in a string with
856 no other multibyte characters, these octal escapes are treated as before.
857 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
858 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
859 Unicode string.
860
861 I have not perpetrated such confusion in PCRE. Up till now, it took just
862 the bottom 8 bits, as in old Perl. I have now made octal escapes with
863 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
864 translate to the appropriate multibyte character.
865
866 29. Applied some refactoring to reduce the number of warnings from Microsoft
867 and Borland compilers. This has included removing the fudge introduced
868 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
869 a warning about an unused variable.
870
871 21. PCRE has not included VT (character 0x0b) in the set of whitespace
872 characters since release 4.0, because Perl (from release 5.004) does not.
873 [Or at least, is documented not to: some releases seem to be in conflict
874 with the documentation.] However, when a pattern was studied with
875 pcre_study() and all its branches started with \s, PCRE still included VT
876 as a possible starting character. Of course, this did no harm; it just
877 caused an unnecessary match attempt.
878
879 22. Removed a now-redundant internal flag bit that recorded the fact that case
880 dependency changed within the pattern. This was once needed for "required
881 byte" processing, but is no longer used. This recovers a now-scarce options
882 bit. Also moved the least significant internal flag bit to the most-
883 significant bit of the word, which was not previously used (hangover from
884 the days when it was an int rather than a uint) to free up another bit for
885 the future.
886
887 23. Added support for CRLF line endings as well as CR and LF. As well as the
888 default being selectable at build time, it can now be changed at runtime
889 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
890 specify that it is scanning data with non-default line endings.
891
892 24. Changed the definition of CXXLINK to make it agree with the definition of
893 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
894
895 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
896 recursions. This makes a big different to stack usage for some patterns.
897
898 26. If a subpattern containing a named recursion or subroutine reference such
899 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
900 the space required for the compiled pattern went wrong and gave too small a
901 value. Depending on the environment, this could lead to "Failed: internal
902 error: code overflow at offset 49" or "glibc detected double free or
903 corruption" errors.
904
905 27. Applied patches from Google (a) to support the new newline modes and (b) to
906 advance over multibyte UTF-8 characters in GlobalReplace.
907
908 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
909 difference for some implementation of PCRE in some Windows version.
910
911 29. Added some extra testing facilities to pcretest:
912
913 \q<number> in a data line sets the "match limit" value
914 \Q<number> in a data line sets the "match recursion limt" value
915 -S <number> sets the stack size, where <number> is in megabytes
916
917 The -S option isn't available for Windows.
918
919
920 Version 6.6 06-Feb-06
921 ---------------------
922
923 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
924 in pcreposix.h. I have copied the definition from pcre.h.
925
926 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
927 because pcre.h is no longer a built file.
928
929 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
930 not normally included in the compiled code.
931
932
933 Version 6.5 01-Feb-06
934 ---------------------
935
936 1. When using the partial match feature with pcre_dfa_exec(), it was not
937 anchoring the second and subsequent partial matches at the new starting
938 point. This could lead to incorrect results. For example, with the pattern
939 /1234/, partially matching against "123" and then "a4" gave a match.
940
941 2. Changes to pcregrep:
942
943 (a) All non-match returns from pcre_exec() were being treated as failures
944 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
945 error message is output. Some extra information is given for the
946 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
947 probably the only errors that are likely to be caused by users (by
948 specifying a regex that has nested indefinite repeats, for instance).
949 If there are more than 20 of these errors, pcregrep is abandoned.
950
951 (b) A binary zero was treated as data while matching, but terminated the
952 output line if it was written out. This has been fixed: binary zeroes
953 are now no different to any other data bytes.
954
955 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
956 used to set a locale for matching. The --locale=xxxx long option has
957 been added (no short equivalent) to specify a locale explicitly on the
958 pcregrep command, overriding the environment variables.
959
960 (d) When -B was used with -n, some line numbers in the output were one less
961 than they should have been.
962
963 (e) Added the -o (--only-matching) option.
964
965 (f) If -A or -C was used with -c (count only), some lines of context were
966 accidentally printed for the final match.
967
968 (g) Added the -H (--with-filename) option.
969
970 (h) The combination of options -rh failed to suppress file names for files
971 that were found from directory arguments.
972
973 (i) Added the -D (--devices) and -d (--directories) options.
974
975 (j) Added the -F (--fixed-strings) option.
976
977 (k) Allow "-" to be used as a file name for -f as well as for a data file.
978
979 (l) Added the --colo(u)r option.
980
981 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
982 is not present by default.
983
984 3. A nasty bug was discovered in the handling of recursive patterns, that is,
985 items such as (?R) or (?1), when the recursion could match a number of
986 alternatives. If it matched one of the alternatives, but subsequently,
987 outside the recursion, there was a failure, the code tried to back up into
988 the recursion. However, because of the way PCRE is implemented, this is not
989 possible, and the result was an incorrect result from the match.
990
991 In order to prevent this happening, the specification of recursion has
992 been changed so that all such subpatterns are automatically treated as
993 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
994
995 4. I had overlooked the fact that, in some locales, there are characters for
996 which isalpha() is true but neither isupper() nor islower() are true. In
997 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
998 and ordfeminine) are like this. This affected the treatment of \w and \W
999 when they appeared in character classes, but not when they appeared outside
1000 a character class. The bit map for "word" characters is now created
1001 separately from the results of isalnum() instead of just taking it from the
1002 upper, lower, and digit maps. (Plus the underscore character, of course.)
1003
1004 5. The above bug also affected the handling of POSIX character classes such as
1005 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1006 permanent tables. Instead, the bit maps for such a class were previously
1007 created as the appropriate unions of the upper, lower, and digit bitmaps.
1008 Now they are created by subtraction from the [[:word:]] class, which has
1009 its own bitmap.
1010
1011 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1012 It is created by subtracting the vertical space characters (\x09, \x0a,
1013 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1014 subtraction was done in the overall bitmap for a character class, meaning
1015 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1016 be recognized. This bug has been fixed.
1017
1018 7. Patches from the folks at Google:
1019
1020 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1021 real life, but is still worth protecting against".
1022
1023 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1024 regular expressions".
1025
1026 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1027 have it.
1028
1029 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1030 "configure" and the latter not, in order to fix a problem somebody had
1031 with compiling the Arg class on HP-UX.
1032
1033 (e) Improve the error-handling of the C++ wrapper a little bit.
1034
1035 (f) New tests for checking recursion limiting.
1036
1037 8. The pcre_memmove() function, which is used only if the environment does not
1038 have a standard memmove() function (and is therefore rarely compiled),
1039 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1040 returning a result (though PCRE never actually uses the result).
1041
1042 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1043 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1044 returned instead of calling malloc() with an overflowing number that would
1045 most likely cause subsequent chaos.
1046
1047 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1048
1049 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1050 with this option is matched, the nmatch and pmatch options of regexec() are
1051 ignored.
1052
1053 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1054 provided in case anyone wants to the the POSIX interface with UTF-8
1055 strings.
1056
1057 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1058 C++ linking (needed for some HP-UX environments).
1059
1060 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1061 (unused parameter) and in the pcre_printint() function (omitted "default"
1062 switch label when the default is to do nothing).
1063
1064 15. Added some code to make it possible, when PCRE is compiled as a C++
1065 library, to replace subject pointers for pcre_exec() with a smart pointer
1066 class, thus making it possible to process discontinuous strings.
1067
1068 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1069 much the same function. They were added by different people who were trying
1070 to make PCRE easy to compile on non-Unix systems. It has been suggested
1071 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1072 for compiling on Windows systems. I have therefore replaced it with
1073 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1074 defaults to "extern" for C or "extern C" for C++, which works fine on
1075 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1076 SCOPE with something explicit in config.h. In addition:
1077
1078 (a) pcreposix.h still had just "extern" instead of either of these macros;
1079 I have replaced it with PCRE_DATA_SCOPE.
1080
1081 (b) Functions such as _pcre_xclass(), which are internal to the library,
1082 but external in the C sense, all had PCRE_EXPORT in their definitions.
1083 This is apparently wrong for the Windows case, so I have removed it.
1084 (It makes no difference on Unix-like systems.)
1085
1086 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1087 of recursive calls to match(). This is different to MATCH_LIMIT because
1088 that limits the total number of calls to match(), not all of which increase
1089 the depth of recursion. Limiting the recursion depth limits the amount of
1090 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1091 when PCRE is compiled, and changed at run time. A patch from Google adds
1092 this functionality to the C++ interface.
1093
1094 18. Changes to the handling of Unicode character properties:
1095
1096 (a) Updated the table to Unicode 4.1.0.
1097
1098 (b) Recognize characters that are not in the table as "Cn" (undefined).
1099
1100 (c) I revised the way the table is implemented to a much improved format
1101 which includes recognition of ranges. It now supports the ranges that
1102 are defined in UnicodeData.txt, and it also amalgamates other
1103 characters into ranges. This has reduced the number of entries in the
1104 table from around 16,000 to around 3,000, thus reducing its size
1105 considerably. I realized I did not need to use a tree structure after
1106 all - a binary chop search is just as efficient. Having reduced the
1107 number of entries, I extended their size from 6 bytes to 8 bytes to
1108 allow for more data.
1109
1110 (d) Added support for Unicode script names via properties such as \p{Han}.
1111
1112 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1113 matching that character.
1114
1115 20. When matching a repeated Unicode property with a minimum greater than zero,
1116 (for example \pL{2,}), PCRE could look past the end of the subject if it
1117 reached it while seeking the minimum number of characters. This could
1118 happen only if some of the characters were more than one byte long, because
1119 there is a check for at least the minimum number of bytes.
1120
1121 21. Refactored the implementation of \p and \P so as to be more general, to
1122 allow for more different types of property in future. This has changed the
1123 compiled form incompatibly. Anybody with saved compiled patterns that use
1124 \p or \P will have to recompile them.
1125
1126 22. Added "Any" and "L&" to the supported property types.
1127
1128 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1129 but give a compile time error if the value is greater than 0xff.
1130
1131 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1132 accidentally not being installed or uninstalled.
1133
1134 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1135 made were to insert the current release number. This seemed silly, because
1136 it made things harder for people building PCRE on systems that don't run
1137 "configure". I have turned pcre.h into a distributed file, no longer built
1138 by "configure", with the version identification directly included. There is
1139 no longer a pcre.h.in file.
1140
1141 However, this change necessitated a change to the pcre-config script as
1142 well. It is built from pcre-config.in, and one of the substitutions was the
1143 release number. I have updated configure.ac so that ./configure now finds
1144 the release number by grepping pcre.h.
1145
1146 26. Added the ability to run the tests under valgrind.
1147
1148
1149 Version 6.4 05-Sep-05
1150 ---------------------
1151
1152 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1153 "--" to be printed when multiple files were scanned, even when none of the
1154 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1155 consider it to be a bug, and have restored the previous behaviour.
1156
1157 2. A couple of code tidies to get rid of compiler warnings.
1158
1159 3. The pcretest program used to cheat by referring to symbols in the library
1160 whose names begin with _pcre_. These are internal symbols that are not
1161 really supposed to be visible externally, and in some environments it is
1162 possible to suppress them. The cheating is now confined to including
1163 certain files from the library's source, which is a bit cleaner.
1164
1165 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1166 file's purpose clearer.
1167
1168 5. Reorganized pcre_ucp_findchar().
1169
1170
1171 Version 6.3 15-Aug-05
1172 ---------------------
1173
1174 1. The file libpcre.pc.in did not have general read permission in the tarball.
1175
1176 2. There were some problems when building without C++ support:
1177
1178 (a) If C++ support was not built, "make install" and "make test" still
1179 tried to test it.
1180
1181 (b) There were problems when the value of CXX was explicitly set. Some
1182 changes have been made to try to fix these, and ...
1183
1184 (c) --disable-cpp can now be used to explicitly disable C++ support.
1185
1186 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1187 backslash in a target when C++ was disabled. This confuses some
1188 versions of "make", apparently. Using an intermediate variable solves
1189 this. (Same for CPP_LOBJ.)
1190
1191 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1192 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1193 necessary on certain architectures.
1194
1195 4. Added a setting of -export-symbols-regex to the link command to remove
1196 those symbols that are exported in the C sense, but actually are local
1197 within the library, and not documented. Their names all begin with
1198 "_pcre_". This is not a perfect job, because (a) we have to except some
1199 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1200 available (and never for static libraries). I have made a note to try to
1201 find a way round (a) in the future.
1202
1203
1204 Version 6.2 01-Aug-05
1205 ---------------------
1206
1207 1. There was no test for integer overflow of quantifier values. A construction
1208 such as {1111111111111111} would give undefined results. What is worse, if
1209 a minimum quantifier for a parenthesized subpattern overflowed and became
1210 negative, the calculation of the memory size went wrong. This could have
1211 led to memory overwriting.
1212
1213 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1214
1215 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1216 operating environments where this matters.
1217
1218 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1219 PCRE options from within the C++ wrapper.
1220
1221 5. Named capturing subpatterns were not being correctly counted when a pattern
1222 was compiled. This caused two problems: (a) If there were more than 100
1223 such subpatterns, the calculation of the memory needed for the whole
1224 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1225 back references of the form \12, where the number was greater than 9, were
1226 not recognized as back references, even though there were sufficient
1227 previous subpatterns.
1228
1229 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1230 versions of gcc, e.g. 2.95.4.
1231
1232
1233 Version 6.1 21-Jun-05
1234 ---------------------
1235
1236 1. There was one reference to the variable "posix" in pcretest.c that was not
1237 surrounded by "#if !defined NOPOSIX".
1238
1239 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1240 the cross-check on the old pcre_info() function, for the benefit of the
1241 cut-down version of PCRE that is currently imported into Exim.
1242
1243 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1244 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1245 patterns that start (?i) but I don't think that matters. The use of (?i) is
1246 just an example; this all applies to the other options as well.
1247
1248 4. Since libtool seems to echo the compile commands it is issuing, the output
1249 from "make" can be reduced a bit by putting "@" in front of each libtool
1250 compile command.
1251
1252 5. Patch from the folks at Google for configure.in to be a bit more thorough
1253 in checking for a suitable C++ installation before trying to compile the
1254 C++ stuff. This should fix a reported problem when a compiler was present,
1255 but no suitable headers.
1256
1257 6. The man pages all had just "PCRE" as their title. I have changed them to
1258 be the relevant file name. I have also arranged that these names are
1259 retained in the file doc/pcre.txt, which is a concatenation in text format
1260 of all the man pages except the little individual ones for each function.
1261
1262 7. The NON-UNIX-USE file had not been updated for the different set of source
1263 files that come with release 6. I also added a few comments about the C++
1264 wrapper.
1265
1266
1267 Version 6.0 07-Jun-05
1268 ---------------------
1269
1270 1. Some minor internal re-organization to help with my DFA experiments.
1271
1272 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1273 didn't matter for the library itself when fully configured, but did matter
1274 when compiling without UCP support, or within Exim, where the ucp files are
1275 not imported.
1276
1277 3. Refactoring of the library code to split up the various functions into
1278 different source modules. The addition of the new DFA matching code (see
1279 below) to a single monolithic source would have made it really too
1280 unwieldy, quite apart from causing all the code to be include in a
1281 statically linked application, when only some functions are used. This is
1282 relevant even without the DFA addition now that patterns can be compiled in
1283 one application and matched in another.
1284
1285 The downside of splitting up is that there have to be some external
1286 functions and data tables that are used internally in different modules of
1287 the library but which are not part of the API. These have all had their
1288 names changed to start with "_pcre_" so that they are unlikely to clash
1289 with other external names.
1290
1291 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1292 a different (DFA) algorithm. Although it is slower than the original
1293 function, it does have some advantages for certain types of matching
1294 problem.
1295
1296 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1297 including restarting after a partial match.
1298
1299 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1300 defined when compiling for Windows was sent to me. I have put it into the
1301 code, though I have no means of testing or verifying it.
1302
1303 7. Added the pcre_refcount() auxiliary function.
1304
1305 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1306 match before or at the first newline in the subject string. In pcretest,
1307 the /f option on a pattern can be used to set this.
1308
1309 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1310 would behave wrongly. This has been present in PCRE since release 4.0.
1311
1312 10. A number of changes to the pcregrep command:
1313
1314 (a) Refactored how -x works; insert ^(...)$ instead of setting
1315 PCRE_ANCHORED and checking the length, in preparation for adding
1316 something similar for -w.
1317
1318 (b) Added the -w (match as a word) option.
1319
1320 (c) Refactored the way lines are read and buffered so as to have more
1321 than one at a time available.
1322
1323 (d) Implemented a pcregrep test script.
1324
1325 (e) Added the -M (multiline match) option. This allows patterns to match
1326 over several lines of the subject. The buffering ensures that at least
1327 8K, or the rest of the document (whichever is the shorter) is available
1328 for matching (and similarly the previous 8K for lookbehind assertions).
1329
1330 (f) Changed the --help output so that it now says
1331
1332 -w, --word-regex(p)
1333
1334 instead of two lines, one with "regex" and the other with "regexp"
1335 because that confused at least one person since the short forms are the
1336 same. (This required a bit of code, as the output is generated
1337 automatically from a table. It wasn't just a text change.)
1338
1339 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1340 option but starts with a hyphen. Could be a pattern or a path name
1341 starting with a hyphen, for instance.
1342
1343 (h) "-" can be given as a file name to represent stdin.
1344
1345 (i) When file names are being printed, "(standard input)" is used for
1346 the standard input, for compatibility with GNU grep. Previously
1347 "<stdin>" was used.
1348
1349 (j) The option --label=xxx can be used to supply a name to be used for
1350 stdin when file names are being printed. There is no short form.
1351
1352 (k) Re-factored the options decoding logic because we are going to add
1353 two more options that take data. Such options can now be given in four
1354 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1355
1356 (l) Added the -A, -B, and -C options for requesting that lines of context
1357 around matches be printed.
1358
1359 (m) Added the -L option to print the names of files that do not contain
1360 any matching lines, that is, the complement of -l.
1361
1362 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1363 continue to scan other files.
1364
1365 (o) The -s option was incorrectly implemented. For compatibility with other
1366 greps, it now suppresses the error message for a non-existent or non-
1367 accessible file (but not the return code). There is a new option called
1368 -q that suppresses the output of matching lines, which was what -s was
1369 previously doing.
1370
1371 (p) Added --include and --exclude options to specify files for inclusion
1372 and exclusion when recursing.
1373
1374 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1375 Hopefully, it now does.
1376
1377 12. Missing cast in pcre_study().
1378
1379 13. Added an "uninstall" target to the makefile.
1380
1381 14. Replaced "extern" in the function prototypes in Makefile.in with
1382 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1383 world, but is set differently for Windows.
1384
1385 15. Added a second compiling function called pcre_compile2(). The only
1386 difference is that it has an extra argument, which is a pointer to an
1387 integer error code. When there is a compile-time failure, this is set
1388 non-zero, in addition to the error test pointer being set to point to an
1389 error message. The new argument may be NULL if no error number is required
1390 (but then you may as well call pcre_compile(), which is now just a
1391 wrapper). This facility is provided because some applications need a
1392 numeric error indication, but it has also enabled me to tidy up the way
1393 compile-time errors are handled in the POSIX wrapper.
1394
1395 16. Added VPATH=.libs to the makefile; this should help when building with one
1396 prefix path and installing with another. (Or so I'm told by someone who
1397 knows more about this stuff than I do.)
1398
1399 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1400 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1401 match everything, including newlines. This is not POSIX-compatible, but
1402 somebody wanted the feature. From pcretest it can be activated by using
1403 both the P and the s flags.
1404
1405 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1406
1407 19. libpcre.pc was being incorrectly installed as executable.
1408
1409 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1410 it now also looks for '\r' so that it will work unmodified on Windows.
1411
1412 21. Added Google's contributed C++ wrapper to the distribution.
1413
1414 22. Added some untidy missing memory free() calls in pcretest, to keep
1415 Electric Fence happy when testing.
1416
1417
1418
1419 Version 5.0 13-Sep-04
1420 ---------------------
1421
1422 1. Internal change: literal characters are no longer packed up into items
1423 containing multiple characters in a single byte-string. Each character
1424 is now matched using a separate opcode. However, there may be more than one
1425 byte in the character in UTF-8 mode.
1426
1427 2. The pcre_callout_block structure has two new fields: pattern_position and
1428 next_item_length. These contain the offset in the pattern to the next match
1429 item, and its length, respectively.
1430
1431 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1432 insertion of callouts before each pattern item. Added the /C option to
1433 pcretest to make use of this.
1434
1435 4. On the advice of a Windows user, the lines
1436
1437 #if defined(_WIN32) || defined(WIN32)
1438 _setmode( _fileno( stdout ), 0x8000 );
1439 #endif /* defined(_WIN32) || defined(WIN32) */
1440
1441 have been added to the source of pcretest. This apparently does useful
1442 magic in relation to line terminators.
1443
1444 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1445 for the benefit of those environments where the "b" makes a difference.
1446
1447 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1448 to know about it. I have put a hack into configure.in that adds in code
1449 to set GCC=yes if CC=icc. This seems to end up at a point in the
1450 generated configure script that is early enough to affect the setting of
1451 compiler options, which is what is needed, but I have no means of testing
1452 whether it really works. (The user who reported this had patched the
1453 generated configure script, which of course I cannot do.)
1454
1455 LATER: After change 22 below (new libtool files), the configure script
1456 seems to know about icc (and also ecc). Therefore, I have commented out
1457 this hack in configure.in.
1458
1459 7. Added support for pkg-config (2 patches were sent in).
1460
1461 8. Negated POSIX character classes that used a combination of internal tables
1462 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1463 [[:^ascii]]. Typically, they would match almost any characters. The other
1464 POSIX classes were not broken in this way.
1465
1466 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1467 to find the match, as PCRE was deluded into thinking that the match had to
1468 start at the start point or following a newline. The same bug applied to
1469 patterns with negative forward assertions or any backward assertions
1470 preceding ".*" at the start, unless the pattern required a fixed first
1471 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1472
1473 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1474 starting at the last subject character, bytes beyond the end of the subject
1475 string were read.
1476
1477 11. Renamed the variable "class" as "classbits" to make life easier for C++
1478 users. (Previously there was a macro definition, but it apparently wasn't
1479 enough.)
1480
1481 12. Added the new field "tables" to the extra data so that tables can be passed
1482 in at exec time, or the internal tables can be re-selected. This allows
1483 a compiled regex to be saved and re-used at a later time by a different
1484 program that might have everything at different addresses.
1485
1486 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1487 -R library as well as a -L library.
1488
1489 14. The debugging options of pcretest (-d on the command line or D on a
1490 pattern) showed incorrect output for anything following an extended class
1491 that contained multibyte characters and which was followed by a quantifier.
1492
1493 15. Added optional support for general category Unicode character properties
1494 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1495 support. It adds about 90K to the size of the library. The meanings of the
1496 inbuilt class escapes such as \d and \s have NOT been changed.
1497
1498 16. Updated pcredemo.c to include calls to free() to release the memory for the
1499 compiled pattern.
1500
1501 17. The generated file chartables.c was being created in the source directory
1502 instead of in the building directory. This caused the build to fail if the
1503 source directory was different from the building directory, and was
1504 read-only.
1505
1506 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1507 file. No doubt somebody will tell me if they don't make sense... Also added
1508 Dan Mooney's comments about building on OpenVMS.
1509
1510 19. Added support for partial matching via the PCRE_PARTIAL option for
1511 pcre_exec() and the \P data escape in pcretest.
1512
1513 20. Extended pcretest with 3 new pattern features:
1514
1515 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1516 write the compiled pattern to the file whose name is "rest-of-line".
1517 This is a straight binary dump of the data, with the saved pointer to
1518 the character tables forced to be NULL. The study data, if any, is
1519 written too. After writing, pcretest reads a new pattern.
1520
1521 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1522 compiled pattern from the given file. There must not be any
1523 occurrences of "<" in the file name (pretty unlikely); if there are,
1524 pcretest will instead treat the initial "<" as a pattern delimiter.
1525 After reading in the pattern, pcretest goes on to read data lines as
1526 usual.
1527
1528 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1529 and 16-bit fields in a compiled pattern, to simulate a pattern that
1530 was compiled on a host of opposite endianness.
1531
1532 21. The pcre-exec() function can now cope with patterns that were compiled on
1533 hosts of opposite endianness, with this restriction:
1534
1535 As for any compiled expression that is saved and used later, the tables
1536 pointer field cannot be preserved; the extra_data field in the arguments
1537 to pcre_exec() should be used to pass in a tables address if a value
1538 other than the default internal tables were used at compile time.
1539
1540 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1541 now diagnosed as an error. Previously, most of the time, a negative number
1542 would have been treated as zero, but if in addition "ovector" was passed as
1543 NULL, a crash could occur.
1544
1545 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1546 new versions from the libtool 1.5 distribution (the last one is a copy of
1547 a file called libtool.m4). This seems to have fixed the need to patch
1548 "configure" to support Darwin 1.3 (which I used to do). However, I still
1549 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1550 workstation).
1551
1552 24. Changed the PCRE licence to be the more standard "BSD" licence.
1553
1554
1555 Version 4.5 01-Dec-03
1556 ---------------------
1557
1558 1. There has been some re-arrangement of the code for the match() function so
1559 that it can be compiled in a version that does not call itself recursively.
1560 Instead, it keeps those local variables that need separate instances for
1561 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1562 needs to "recurse". Keeping track of where control must go is done by means
1563 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1564 hide most of the details from the main code, and operates only if
1565 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1566 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1567 operating.
1568
1569 To make it easier for callers to provide specially tailored get/free
1570 functions for this usage, two new functions, pcre_stack_malloc, and
1571 pcre_stack_free, are used. They are always called in strict stacking order,
1572 and the size of block requested is always the same.
1573
1574 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1575 PCRE has been compiled to use the stack or the heap for recursion. The
1576 -C option of pcretest uses this to show which version is compiled.
1577
1578 A new data escape \S, is added to pcretest; it causes the amounts of store
1579 obtained and freed by both kinds of malloc/free at match time to be added
1580 to the output.
1581
1582 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1583 what's available on my current Linux desktop machine.
1584
1585 3. When matching a UTF-8 string, the test for a valid string at the start has
1586 been extended. If start_offset is not zero, PCRE now checks that it points
1587 to a byte that is the start of a UTF-8 character. If not, it returns
1588 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1589 this is necessary because there may be backward assertions in the pattern.
1590 When matching the same subject several times, it may save resources to use
1591 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1592
1593 4. The code for checking the validity of UTF-8 strings has been tightened so
1594 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1595 containing "overlong sequences".
1596
1597 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1598 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1599 should have been "&", but it just so happened that all the cases this let
1600 through by mistake were picked up later in the function.
1601
1602 6. I had used a variable called "isblank" - this is a C99 function, causing
1603 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1604
1605 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1606 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1607 so the version is shown; (c) stop "make test" echoing "./RunTest".
1608
1609 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1610
1611 9. The prototype for memmove() for systems that don't have it was using
1612 size_t, but the inclusion of the header that defines size_t was later. I've
1613 moved the #includes for the C headers earlier to avoid this.
1614
1615 10. Added some adjustments to the code to make it easier to compiler on certain
1616 special systems:
1617
1618 (a) Some "const" qualifiers were missing.
1619 (b) Added the macro EXPORT before all exported functions; by default this
1620 is defined to be empty.
1621 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1622 that it reads its output file name as an argument instead of writing
1623 to the standard output and assuming this can be redirected.
1624
1625 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1626 class containing characters with values greater than 255, PCRE compilation
1627 went into a loop.
1628
1629 12. A recursive reference to a subpattern that was within another subpattern
1630 that had a minimum quantifier of zero caused PCRE to crash. For example,
1631 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1632 recursion. If the recursively-called subpattern itself had a zero repeat,
1633 that was OK.
1634
1635 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1636 buffer into which it was copied (for escape processing) was still set at
1637 1024, so long lines caused crashes.
1638
1639 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1640 "internal error: code overflow...". This applied to any character class
1641 that was followed by a possessive quantifier.
1642
1643 15. Modified the Makefile to add libpcre.la as a prerequisite for
1644 libpcreposix.la because I was told this is needed for a parallel build to
1645 work.
1646
1647 16. If a pattern that contained .* following optional items at the start was
1648 studied, the wrong optimizing data was generated, leading to matching
1649 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1650 matching string must start with a or b or c. The correct conclusion for
1651 this pattern is that a match can start with any character.
1652
1653
1654 Version 4.4 13-Aug-03
1655 ---------------------
1656
1657 1. In UTF-8 mode, a character class containing characters with values between
1658 127 and 255 was not handled correctly if the compiled pattern was studied.
1659 In fixing this, I have also improved the studying algorithm for such
1660 classes (slightly).
1661
1662 2. Three internal functions had redundant arguments passed to them. Removal
1663 might give a very teeny performance improvement.
1664
1665 3. Documentation bug: the value of the capture_top field in a callout is *one
1666 more than* the number of the hightest numbered captured substring.
1667
1668 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1669 in incorrectly linking with a previously installed version. They now link
1670 explicitly with libpcre.la.
1671
1672 5. configure.in no longer needs to recognize Cygwin specially.
1673
1674 6. A problem in pcre.in for Windows platforms is fixed.
1675
1676 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1677 pcretest, it used to include the size of the study block as part of its
1678 output. Unfortunately, the structure contains a field that has a different
1679 size on different hardware architectures. This meant that the tests that
1680 showed this size failed. As the block is currently always of a fixed size,
1681 this information isn't actually particularly useful in pcretest output, so
1682 I have just removed it.
1683
1684 8. Three pre-processor statements accidentally did not start in column 1.
1685 Sadly, there are *still* compilers around that complain, even though
1686 standard C has not required this for well over a decade. Sigh.
1687
1688 9. In pcretest, the code for checking callouts passed small integers in the
1689 callout_data field, which is a void * field. However, some picky compilers
1690 complained about the casts involved for this on 64-bit systems. Now
1691 pcretest passes the address of the small integer instead, which should get
1692 rid of the warnings.
1693
1694 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1695 both compile and run time, and gives an error if an invalid UTF-8 sequence
1696 is found. There is a option for disabling this check in cases where the
1697 string is known to be correct and/or the maximum performance is wanted.
1698
1699 11. In response to a bug report, I changed one line in Makefile.in from
1700
1701 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1702 to
1703 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1704
1705 to look similar to other lines, but I have no way of telling whether this
1706 is the right thing to do, as I do not use Windows. No doubt I'll get told
1707 if it's wrong...
1708
1709
1710 Version 4.3 21-May-03
1711 ---------------------
1712
1713 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1714 Makefile.
1715
1716 2. Some refactoring to improve the quality of the code:
1717
1718 (i) The utf8_table... variables are now declared "const".
1719
1720 (ii) The code for \cx, which used the "case flipping" table to upper case
1721 lower case letters, now just substracts 32. This is ASCII-specific,
1722 but the whole concept of \cx is ASCII-specific, so it seems
1723 reasonable.
1724
1725 (iii) PCRE was using its character types table to recognize decimal and
1726 hexadecimal digits in the pattern. This is silly, because it handles
1727 only 0-9, a-f, and A-F, but the character types table is locale-
1728 specific, which means strange things might happen. A private
1729 table is now used for this - though it costs 256 bytes, a table is
1730 much faster than multiple explicit tests. Of course, the standard
1731 character types table is still used for matching digits in subject
1732 strings against \d.
1733
1734 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1735 ending in _t are). So I've renamed it as ESC_tee.
1736
1737 3. The first argument for regexec() in the POSIX wrapper should have been
1738 defined as "const".
1739
1740 4. Changed pcretest to use malloc() for its buffers so that they can be
1741 Electric Fenced for debugging.
1742
1743 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1744 to read one or more bytes before the start of the subject string. Often this
1745 had no effect on PCRE's behaviour, but in some circumstances it could
1746 provoke a segmentation fault.
1747
1748 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1749 to try to read one or more bytes before the start of the subject string.
1750
1751 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1752 UTF-8 support could misbehave in various ways if the subject string
1753 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1754 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1755 back over UTF-8 characters.)
1756
1757
1758 Version 4.2 14-Apr-03
1759 ---------------------
1760
1761 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1762
1763 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1764 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1765 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1766 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1767 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1768 and BUILD_EXEEXT
1769 Note: automatic setting of the BUILD variables is not yet working
1770 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1771 compile-time but not at link-time
1772 [LINK]: use for linking executables only
1773 make different versions for Windows and non-Windows
1774 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1775 libraries
1776 [LINK_FOR_BUILD]: new variable
1777 [OBJEXT]: use throughout
1778 [EXEEXT]: use throughout
1779 <winshared>: new target
1780 <wininstall>: new target
1781 <dftables.o>: use native compiler
1782 <dftables>: use native linker
1783 <install>: handle Windows platform correctly
1784 <clean>: ditto
1785 <check>: ditto
1786 copy DLL to top builddir before testing
1787
1788 As part of these changes, -no-undefined was removed again. This was reported
1789 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1790 in any case.
1791
1792 3. Some tidies to get rid of compiler warnings:
1793
1794 . In the match_data structure, match_limit was an unsigned long int, whereas
1795 match_call_count was an int. I've made them both unsigned long ints.
1796
1797 . In pcretest the fact that a const uschar * doesn't automatically cast to
1798 a void * provoked a warning.
1799
1800 . Turning on some more compiler warnings threw up some "shadow" variables
1801 and a few more missing casts.
1802
1803 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1804 option, a class that contained a single character with a value between 128
1805 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1806
1807 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1808 option, a class that contained several characters, but with at least one
1809 whose value was between 128 and 255 caused PCRE to crash.
1810
1811
1812 Version 4.1 12-Mar-03
1813 ---------------------
1814
1815 1. Compiling with gcc -pedantic found a couple of places where casts were
1816 needed, and a string in dftables.c that was longer than standard compilers are
1817 required to support.
1818
1819 2. Compiling with Sun's compiler found a few more places where the code could
1820 be tidied up in order to avoid warnings.
1821
1822 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1823 first of these names is deprecated in the latest Autoconf in favour of the name
1824 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1825 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1826 analogy I have changed it to CFLAGS_FOR_BUILD.
1827
1828 4. Added -no-undefined to the linking command in the Makefile, because this is
1829 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1830 linking step for the pcreposix library.
1831
1832 5. PCRE was failing to diagnose the case of two named groups with the same
1833 name.
1834
1835 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1836 literal character that is needed in the subject for a match, and scans along to
1837 ensure that it is present before embarking on the full matching process. This
1838 saves time in cases of nested unlimited repeats that are never going to match.
1839 Problem: the scan can take a lot of time if the subject is very long (e.g.
1840 megabytes), thus penalizing straightforward matches. It is now done only if the
1841 amount of subject to be scanned is less than 1000 bytes.
1842
1843 7. A lesser problem with the same optimization is that it was recording the
1844 first character of an anchored pattern as "needed", thus provoking a search
1845 right along the subject, even when the first match of the pattern was going to
1846 fail. The "needed" character is now not set for anchored patterns, unless it
1847 follows something in the pattern that is of non-fixed length. Thus, it still
1848 fulfils its original purpose of finding quick non-matches in cases of nested
1849 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1850
1851
1852 Version 4.0 17-Feb-03
1853 ---------------------
1854
1855 1. If a comment in an extended regex that started immediately after a meta-item
1856 extended to the end of string, PCRE compiled incorrect data. This could lead to
1857 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1858
1859 2. Moved to autoconf 2.53 and libtool 1.4.2.
1860
1861 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1862 the special perltest8 script is no longer needed - all the tests can be run
1863 from a single perltest script.
1864
1865 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1866 by \s. It has now been removed in PCRE. This means it isn't recognized as
1867 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1868 class [:space:] *does* include VT, thereby creating a mess.
1869
1870 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1871 space and tab.
1872
1873 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1874 its new features into the main test script, reducing the number of scripts.
1875
1876 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1877 were backward compatible, and made the (?i) apply to the whole pattern, as if
1878 /i were given. Now it behaves more logically, and applies the option setting
1879 only to what follows. PCRE has been changed to follow suit. However, if it
1880 finds options settings right at the start of the pattern, it extracts them into
1881 the global options, as before. Thus, they show up in the info data.
1882
1883 8. Added support for the \Q...\E escape sequence. Characters in between are
1884 treated as literals. This is slightly different from Perl in that $ and @ are
1885 also handled as literals inside the quotes. In Perl, they will cause variable
1886 interpolation. Note the following examples:
1887
1888 Pattern PCRE matches Perl matches
1889
1890 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1891 \Qabc\$xyz\E abc\$xyz abc\$xyz
1892 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1893
1894 For compatibility with Perl, \Q...\E sequences are recognized inside character
1895 classes as well as outside them.
1896
1897 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1898 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1899 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1900 signed/unsigned warnings.
1901
1902 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1903 option for pcretest, so I've replaced it by a simple function that does just
1904 that job.
1905
1906 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1907 "pcregrep -".
1908
1909 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1910 Java package. This provides some syntactic sugar for simple cases of what my
1911 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1912 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1913 item, you can use this simplified notation. Note that only makes sense with
1914 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1915 greediness, whatever the setting of the PCRE_UNGREEDY option.
1916
1917 13. A change of greediness default within a pattern was not taking effect at
1918 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1919 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1920 was abstracted outside.
1921
1922 14. PCRE now supports the \G assertion. It is true when the current matching
1923 position is at the start point of the match. This differs from \A when the
1924 starting offset is non-zero. Used with the /g option of pcretest (or similar
1925 code), it works in the same way as it does for Perl's /g option. If all
1926 alternatives of a regex begin with \G, the expression is anchored to the start
1927 match position, and the "anchored" flag is set in the compiled expression.
1928
1929 15. Some bugs concerning the handling of certain option changes within patterns
1930 have been fixed. These applied to options other than (?ims). For example,
1931 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1932 been the other way round. Some of this was related to change 7 above.
1933
1934 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1935 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1936 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1937 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1938
1939 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1940 mode. Unlike ".", it always matches newline, whatever the setting of
1941 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1942 assertions. Perl allows it, but it doesn't (in general) work because it can't
1943 calculate the length of the lookbehind. At least, that's the case for Perl
1944 5.8.0 - I've been told they are going to document that it doesn't work in
1945 future.
1946
1947 18. Added an error diagnosis for escapes that PCRE does not support: these are
1948 \L, \l, \N, \P, \p, \U, \u, and \X.
1949
1950 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1951 reading past the end of the pattern in cases such as /[abcd/.
1952
1953 20. PCRE was getting more memory than necessary for patterns with classes that
1954 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1955
1956 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1957 compiling PCRE for use with Virtual Pascal.
1958
1959 22. Small fix to the Makefile to make it work properly if the build is done
1960 outside the source tree.
1961
1962 23. Added a new extension: a condition to go with recursion. If a conditional
1963 subpattern starts with (?(R) the "true" branch is used if recursion has
1964 happened, whereas the "false" branch is used only at the top level.
1965
1966 24. When there was a very long string of literal characters (over 255 bytes
1967 without UTF support, over 250 bytes with UTF support), the computation of how
1968 much memory was required could be incorrect, leading to segfaults or other
1969 strange effects.
1970
1971 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1972 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1973 there was a subsequent back reference to those brackets. This meant that, for
1974 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1975 possible to check for precisely this case. All we can do is abandon the
1976 optimization if .* occurs inside capturing brackets when there are any back
1977 references whatsoever. (See below for a better fix that came later.)
1978
1979 26. The handling of the optimization for finding the first character of a
1980 non-anchored pattern, and for finding a character that is required later in the
1981 match were failing in some cases. This didn't break the matching; it just
1982 failed to optimize when it could. The way this is done has been re-implemented.
1983
1984 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1985
1986 28. Added a new feature that provides some of the functionality that Perl
1987 provides with (?{...}). The facility is termed a "callout". The way it is done
1988 in PCRE is for the caller to provide an optional function, by setting
1989 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1990 global variable. By default it is unset, which disables all calling out. To get
1991 the function called, the regex must include (?C) at appropriate points. This
1992 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1993 This provides a means of identifying different callout points. When PCRE
1994 reaches such a point in the regex, if pcre_callout has been set, the external
1995 function is called. It is provided with data in a structure called
1996 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1997 matching continues; if it returns a non-zero value, the match at the current
1998 point fails. However, backtracking will occur if possible. [This was changed
1999 later and other features added - see item 49 below.]
2000
2001 29. pcretest is upgraded to test the callout functionality. It provides a
2002 callout function that displays information. By default, it shows the start of
2003 the match and the current position in the text. There are some new data escapes
2004 to vary what happens:
2005
2006 \C+ in addition, show current contents of captured substrings
2007 \C- do not supply a callout function
2008 \C!n return 1 when callout number n is reached
2009 \C!n!m return 1 when callout number n is reached for the mth time
2010
2011 30. If pcregrep was called with the -l option and just a single file name, it
2012 output "<stdin>" if a match was found, instead of the file name.
2013
2014 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2015 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2016 pcre_exec(). This saves a malloc/free per call. The default value of
2017 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2018 when configuring.
2019
2020 32. The default maximum size of a compiled pattern is 64K. There have been a
2021 few cases of people hitting this limit. The code now uses macros to handle the
2022 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2023 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2024 configuring. Tests 2 and 5 work only with 2-byte links because they output
2025 debugging information about compiled patterns.
2026
2027 33. Internal code re-arrangements:
2028
2029 (a) Moved the debugging function for printing out a compiled regex into
2030 its own source file (printint.c) and used #include to pull it into
2031 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2032 separate copies.
2033
2034 (b) Defined the list of op-code names for debugging as a macro in
2035 internal.h so that it is next to the definition of the opcodes.
2036
2037 (c) Defined a table of op-code lengths for simpler skipping along compiled
2038 code. This is again a macro in internal.h so that it is next to the
2039 definition of the opcodes.
2040
2041 34. Added support for recursive calls to individual subpatterns, along the
2042 lines of Robin Houston's patch (but implemented somewhat differently).
2043
2044 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2045 allow it to read and process whole directories in Win32. This code was
2046 contributed by Lionel Fourquaux; it has not been tested by me.
2047
2048 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2049 used to name a group. Names consist of alphanumerics and underscores, and must
2050 be unique. Back references use the syntax (?P=name) and recursive calls use
2051 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2052 numbers. The function pcre_fullinfo() can be used after compilation to extract
2053 a name/number map. There are three relevant calls:
2054
2055 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2056 PCRE_INFO_NAMECOUNT yields the number of entries
2057 PCRE_INFO_NAMETABLE yields a pointer to the map.
2058
2059 The map is a vector of fixed-size entries. The size of each entry depends on
2060 the length of the longest name used. The first two bytes of each entry are the
2061 group number, most significant byte first. There follows the corresponding
2062 name, zero terminated. The names are in alphabetical order.
2063
2064 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2065 case instead of 255. Making it the same both with and without UTF-8 support
2066 means that the same test output works with both.
2067
2068 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2069 calling malloc() with a zero argument.
2070
2071 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2072 optimization. I've improved things by keeping a bitmap of backreferences with
2073 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2074 fact referenced, the optimization can be applied. It is unlikely that a
2075 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2076 the match to follow \n) will appear inside brackets with a number greater than
2077 31, but if it does, any back reference > 31 suppresses the optimization.
2078
2079 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2080 of disabling numbered capturing parentheses. Any opening parenthesis that is
2081 not followed by ? behaves as if it were followed by ?: but named parentheses
2082 can still be used for capturing (and they will acquire numbers in the usual
2083 way).
2084
2085 41. Redesigned the return codes from the match() function into yes/no/error so
2086 that errors can be passed back from deep inside the nested calls. A malloc
2087 failure while inside a recursive subpattern call now causes the
2088 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2089
2090 42. It is now possible to set a limit on the number of times the match()
2091 function is called in a call to pcre_exec(). This facility makes it possible to
2092 limit the amount of recursion and backtracking, though not in a directly
2093 obvious way, because the match() function is used in a number of different
2094 circumstances. The count starts from zero for each position in the subject
2095 string (for non-anchored patterns). The default limit is, for compatibility, a
2096 large number, namely 10 000 000. You can change this in two ways:
2097
2098 (a) When configuring PCRE before making, you can use --with-match-limit=n
2099 to set a default value for the compiled library.
2100
2101 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2102 a different value is set. See 45 below.
2103
2104 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2105
2106 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2107 of things that can be changed at compile time. The first argument specifies
2108 what is wanted and the second points to where the information is to be placed.
2109 The current list of available information is:
2110
2111 PCRE_CONFIG_UTF8
2112
2113 The output is an integer that is set to one if UTF-8 support is available;
2114 otherwise it is set to zero.
2115
2116 PCRE_CONFIG_NEWLINE
2117
2118 The output is an integer that it set to the value of the code that is used for
2119 newline. It is either LF (10) or CR (13).
2120
2121 PCRE_CONFIG_LINK_SIZE
2122
2123 The output is an integer that contains the number of bytes used for internal
2124 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2125
2126 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2127
2128 The output is an integer that contains the threshold above which the POSIX
2129 interface uses malloc() for output vectors. See item 31 above.
2130
2131 PCRE_CONFIG_MATCH_LIMIT
2132
2133 The output is an unsigned integer that contains the default limit of the number
2134 of match() calls in a pcre_exec() execution. See 42 above.
2135
2136 44. pcretest has been upgraded by the addition of the -C option. This causes it
2137 to extract all the available output from the new pcre_config() function, and to
2138 output it. The program then exits immediately.
2139
2140 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2141 order to support additional features. One way would have been to define
2142 pcre_exec2() (for example) with extra arguments, but this would not have been
2143 extensible, and would also have required all calls to the original function to
2144 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2145 is used for passing in "extra" data from pcre_study().
2146
2147 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2148 contains the following fields:
2149
2150 flags a bitmap indicating which of the following fields are set
2151 study_data opaque data from pcre_study()
2152 match_limit a way of specifying a limit on match() calls for a specific
2153 call to pcre_exec()
2154 callout_data data for callouts (see 49 below)
2155
2156 The flag bits are also defined in pcre.h, and are
2157
2158 PCRE_EXTRA_STUDY_DATA
2159 PCRE_EXTRA_MATCH_LIMIT
2160 PCRE_EXTRA_CALLOUT_DATA
2161
2162 The pcre_study() function now returns one of these new pcre_extra blocks, with
2163 the actual study data pointed to by the study_data field, and the
2164 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2165 before. That is, this change is entirely upwards-compatible and requires no
2166 change to existing code.
2167
2168 If you want to pass in additional data to pcre_exec(), you can either place it
2169 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2170 block.
2171
2172 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2173 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2174 times with different match limits, until it finds the minimum value needed for
2175 pcre_exec() to complete. The value is then output. This can be instructive; for
2176 most simple matches the number is quite small, but for pathological cases it
2177 gets very large very quickly.
2178
2179 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2180 returns the size of the data block pointed to by the study_data field in a
2181 pcre_extra block, that is, the value that was passed as the argument to
2182 pcre_malloc() when PCRE was getting memory in which to place the information
2183 created by pcre_study(). The fourth argument should point to a size_t variable.
2184 pcretest has been extended so that this information is shown after a successful
2185 pcre_study() call when information about the compiled regex is being displayed.
2186
2187 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2188 because what follows is always an absolute path. (Later: it turns out that this
2189 is more than cosmetic for MinGW, because it doesn't like empty path
2190 components.)
2191
2192 49. Some changes have been made to the callout feature (see 28 above):
2193
2194 (i) A callout function now has three choices for what it returns:
2195
2196 0 => success, carry on matching
2197 > 0 => failure at this point, but backtrack if possible
2198 < 0 => serious error, return this value from pcre_exec()
2199
2200 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2201 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2202 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2203 use by callout functions. It will never be used by PCRE itself.
2204
2205 (ii) The pcre_extra structure (see 45 above) has a void * field called
2206 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2207 pcre_callout_block structure has a field of the same name. The contents of
2208 the field passed in the pcre_extra structure are passed to the callout
2209 function in the corresponding field in the callout block. This makes it
2210 easier to use the same callout-containing regex from multiple threads. For
2211 testing, the pcretest program has a new data escape
2212
2213 \C*n pass the number n (may be negative) as callout_data
2214
2215 If the callout function in pcretest receives a non-zero value as
2216 callout_data, it returns that value.
2217
2218 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2219 there were some redundant $(CFLAGS) in commands that are now specified as
2220 $(LINK), which already includes $(CFLAGS).
2221
2222 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2223 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2224 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2225 one-byte characters throughout. Note that case-insensitive matching applies
2226 only to characters whose values are less than 256. PCRE doesn't support the
2227 notion of cases for higher-valued characters.
2228
2229 (i) A character class whose characters are all within 0-255 is handled as
2230 a bit map, and the map is inverted for negative classes. Previously, a
2231 character > 255 always failed to match such a class; however it should
2232 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2233
2234 (ii) A negated character class with a single character < 255 is coded as
2235 "not this character" (OP_NOT). This wasn't working properly when the test
2236 character was multibyte, either singly or repeated.
2237
2238 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2239 mode, for example: \x{100}{2,3}.
2240
2241 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2242 singly or repeated) now correctly test multibyte characters. However,
2243 PCRE doesn't recognize any characters with values greater than 255 as
2244 digits, spaces, or word characters. Such characters always match \D, \S,
2245 and \W, and never match \d, \s, or \w.
2246
2247 (v) Classes may now contain characters and character ranges with values
2248 greater than 255. For example: [ab\x{100}-\x{400}].
2249
2250 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2251 PCRE in UTF-8 mode.
2252
2253 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2254 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2255 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2256 value.)
2257
2258 53. The single man page has become too large. I have therefore split it up into
2259 a number of separate man pages. These also give rise to individual HTML pages;
2260 these are now put in a separate directory, and there is an index.html page that
2261 lists them all. Some hyperlinking between the pages has been installed.
2262
2263 54. Added convenience functions for handling named capturing parentheses.
2264
2265 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2266 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2267 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2268 are faulted.
2269
2270 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2271 calling configure. These values are used when compiling the dftables.c program
2272 which is run to generate the source of the default character tables. They
2273 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2274 you will need to set these values.
2275
2276 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2277
2278
2279 Version 3.9 02-Jan-02
2280 ---------------------
2281
2282 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2283
2284 2. If --disable-static was given, the building process failed when trying to
2285 build pcretest and pcregrep. (For some reason it was using libtool to compile
2286 them, which is not right, as they aren't part of the library.)
2287
2288
2289 Version 3.8 18-Dec-01
2290 ---------------------
2291
2292 1. The experimental UTF-8 code was completely screwed up. It was packing the
2293 bytes in the wrong order. How dumb can you get?
2294
2295
2296 Version 3.7 29-Oct-01
2297 ---------------------
2298
2299 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2300 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2301 this didn't happen under Solaris 8, where I normally test things.
2302
2303 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2304 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2305 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2306 this fix an hour or so after the initial 3.7 release.)
2307
2308
2309 Version 3.6 23-Oct-01
2310 ---------------------
2311
2312 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2313 offsets passed as NULL with zero offset count.
2314
2315 2. The config.guess and config.sub files had not been updated when I moved to
2316 the latest autoconf.
2317
2318
2319 Version 3.5 15-Aug-01
2320 ---------------------
2321
2322 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2323 had been forgotten.
2324
2325 2. By using declared but undefined structures, we can avoid using "void"
2326 definitions in pcre.h while keeping the internal definitions of the structures
2327 private.
2328
2329 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2330 user point of view, this means that both static and shared libraries are built
2331 by default, but this can be individually controlled. More of the work of
2332 handling this static/shared cases is now inside libtool instead of PCRE's make
2333 file.
2334
2335 4. The pcretest utility is now installed along with pcregrep because it is
2336 useful for users (to test regexs) and by doing this, it automatically gets
2337 relinked by libtool. The documentation has been turned into a man page, so
2338 there are now .1, .txt, and .html versions in /doc.
2339
2340 5. Upgrades to pcregrep:
2341 (i) Added long-form option names like gnu grep.
2342 (ii) Added --help to list all options with an explanatory phrase.
2343 (iii) Added -r, --recursive to recurse into sub-directories.
2344 (iv) Added -f, --file to read patterns from a file.
2345
2346 6. pcre_exec() was referring to its "code" argument before testing that
2347 argument for NULL (and giving an error if it was NULL).
2348
2349 7. Upgraded Makefile.in to allow for compiling in a different directory from
2350 the source directory.
2351
2352 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2353 options bits, the pointer it was passed was to an int instead of to an unsigned
2354 long int. This mattered only on 64-bit systems.
2355
2356 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2357 generated) instead of pcre.in, which it its source. Also made the same change
2358 in several of the .c files.
2359
2360 10. A new release of gcc defines printf() as a macro, which broke pcretest
2361 because it had an ifdef in the middle of a string argument for printf(). Fixed
2362 by using separate calls to printf().
2363
2364 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2365 script, to force use of CR or LF instead of \n in the source. On non-Unix
2366 systems, the value can be set in config.h.
2367
2368 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2369 absolute limit. Changed the text of the error message to make this clear, and
2370 likewise updated the man page.
2371
2372 13. The limit of 99 on the number of capturing subpatterns has been removed.
2373 The new limit is 65535, which I hope will not be a "real" limit.
2374
2375
2376 Version 3.4 22-Aug-00
2377 ---------------------
2378
2379 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2380
2381 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2382
2383
2384 Version 3.3 01-Aug-00
2385 ---------------------
2386
2387 1. If an octal character was given, but the value was greater than \377, it
2388 was not getting masked to the least significant bits, as documented. This could
2389 lead to crashes in some systems.
2390
2391 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2392 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2393
2394 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2395 These just pass their arguments on to (pcre_free)(), but they are provided
2396 because some uses of PCRE bind it to non-C systems that can call its functions,
2397 but cannot call free() or pcre_free() directly.
2398
2399 4. Add "make test" as a synonym for "make check". Corrected some comments in
2400 the Makefile.
2401
2402 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2403 Makefile.
2404
2405 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2406 command called pgrep for grepping around the active processes.
2407
2408 7. Added the beginnings of support for UTF-8 character strings.
2409
2410 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2411 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2412 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2413 out for the ar command.)
2414
2415
2416 Version 3.2 12-May-00
2417 ---------------------
2418
2419 This is purely a bug fixing release.
2420
2421 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2422 of ZA. This was just one example of several cases that could provoke this bug,
2423 which was introduced by change 9 of version 2.00. The code for breaking
2424 infinite loops after an iteration that matches an empty string was't working
2425 correctly.
2426
2427 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2428 when matched against abbab (for example). After matching an empty string, it
2429 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2430 caused it to match further down the string than it should.
2431
2432 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2433 was there because it doesn't seem to be needed, and it causes trouble on some
2434 systems, as it is not a Standard C header. It has been removed.
2435
2436 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2437 were reported on the Macintosh. The changes were from
2438
2439 while ((c = *(++ptr)) != 0 && c != '\n');
2440 to
2441 while ((c = *(++ptr)) != 0 && c != '\n') ;
2442
2443 Totally extraordinary, but if that's what it takes...
2444
2445 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2446 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2447 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2448 assumes the way PCRE uses memmove() (always moving upwards).
2449
2450 6. PCRE is being used in one environment where strchr() is not available. There
2451 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2452 faster code anyway.
2453
2454
2455 Version 3.1 09-Feb-00
2456 ---------------------
2457
2458 The only change in this release is the fixing of some bugs in Makefile.in for
2459 the "install" target:
2460
2461 (1) It was failing to install pcreposix.h.
2462
2463 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2464
2465
2466 Version 3.0 01-Feb-00
2467 ---------------------
2468
2469 1. Add support for the /+ modifier to perltest (to output $` like it does in
2470 pcretest).
2471
2472 2. Add support for the /g modifier to perltest.
2473
2474 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2475 matches null strings.
2476
2477 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2478 pattern. Perl treats empty patterns specially - it reuses the most recent
2479 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2480 effect.
2481
2482 5. The POSIX interface was broken in that it was just handing over the POSIX
2483 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2484 required a bigger vector, with some working space on the end. This means that
2485 the POSIX wrapper now has to get and free some memory, and copy the results.
2486
2487 6. Added some simple autoconf support, placing the test data and the
2488 documentation in separate directories, re-organizing some of the
2489 information files, and making it build pcre-config (a GNU standard). Also added
2490 libtool support for building PCRE as a shared library, which is now the
2491 default.
2492
2493 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2494 09 are not valid octal constants. Single digits will be used for minor values
2495 less than 10.
2496
2497 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2498 existing programs that set these in the POSIX interface can use PCRE without
2499 modification.
2500
2501 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2502 return all that pcre_info() returns, plus additional data. The pcre_info()
2503 function is retained for compatibility, but is considered to be obsolete.
2504
2505 10. Added experimental recursion feature (?R) to handle one common case that
2506 Perl 5.6 will be able to do with (?p{...}).
2507
2508 11. Added support for POSIX character classes like [:alpha:], which Perl is
2509 adopting.
2510
2511
2512 Version 2.08 31-Aug-99
2513 ----------------------
2514
2515 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2516 trying to match at the startoffset position, but instead was moving forward to
2517 the next newline as if a previous match had failed.
2518
2519 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2520 and could get into a loop if a null string was matched other than at the start
2521 of the subject.
2522
2523 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2524 be distinguished at compile time, and for completeness also added PCRE_DATE.
2525
2526 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2527 in GnuWin32 environments.
2528
2529
2530 Version 2.07 29-Jul-99
2531 ----------------------
2532
2533 1. The documentation is now supplied in plain text form and HTML as well as in
2534 the form of man page sources.
2535
2536 2. C++ compilers don't like assigning (void *) values to other pointer types.
2537 In particular this affects malloc(). Although there is no problem in Standard
2538 C, I've put in casts to keep C++ compilers happy.
2539
2540 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2541 should be (const char *).
2542
2543 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2544 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2545 However, I haven't made this a standard facility. The documentation doesn't
2546 mention it, and the Makefile doesn't support it.
2547
2548 5. The Makefile now contains an "install" target, with editable destinations at
2549 the top of the file. The pcretest program is not installed.
2550
2551 6. pgrep -V now gives the PCRE version number and date.
2552
2553 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2554 causing the entire string to be ignored, instead of just the last character.
2555
2556 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2557 non-matching string, it can take a very, very long time, even for strings of
2558 quite modest length, because of the nested recursion. PCRE now does better in
2559 some of these cases. It does this by remembering the last required literal
2560 character in the pattern, and pre-searching the subject to ensure it is present
2561 before running the real match. In other words, it applies a heuristic to detect
2562 some types of certain failure quickly, and in the above example, if presented
2563 with a string that has no trailing " it gives "no match" very quickly.
2564
2565 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2566 other alternatives are tried instead.
2567
2568
2569 Version 2.06 09-Jun-99
2570 ----------------------
2571
2572 1. Change pcretest's output for amount of store used to show just the code
2573 space, because the remainder (the data block) varies in size between 32-bit and
2574 64-bit systems.
2575
2576 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2577 start matching at. This allows lookbehinds to work when searching for multiple
2578 occurrences in a string.
2579
2580 3. Added additional options to pcretest for testing multiple occurrences:
2581
2582 /+ outputs the rest of the string that follows a match
2583 /g loops for multiple occurrences, using the new startoffset argument
2584 /G loops for multiple occurrences by passing an incremented pointer
2585
2586 4. PCRE wasn't doing the "first character" optimization for patterns starting
2587 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2588 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2589 the letter 'x'. On long subject strings, this gives a significant speed-up.
2590
2591
2592 Version 2.05 21-Apr-99
2593 ----------------------
2594
2595 1. Changed the type of magic_number from int to long int so that it works
2596 properly on 16-bit systems.
2597
2598 2. Fixed a bug which caused patterns starting with .* not to work correctly
2599 when the subject string contained newline characters. PCRE was assuming
2600 anchoring for such patterns in all cases, which is not correct because .* will
2601 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2602 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2603 must be retried after every newline in the subject.
2604
2605
2606 Version 2.04 18-Feb-99
2607 ----------------------
2608
2609 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2610 computation of the store needed to hold the pattern was incorrect (too large).
2611 If such patterns were nested a few deep, this could multiply and become a real
2612 problem.
2613
2614 2. Added /M option to pcretest to show the memory requirement of a specific
2615 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2616
2617 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2618 compiled in such a way that the backtracking after subsequent failure was
2619 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2620 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2621
2622
2623 Version 2.03 02-Feb-99
2624 ----------------------
2625
2626 1. Fixed typo and small mistake in man page.
2627
2628 2. Added 4th condition (GPL supersedes if conflict) and created separate
2629 LICENCE file containing the conditions.
2630
2631 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2632 Perl, that is the internal \ allows the delimiter to be included in the
2633 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2634 the final delimiter, add \ to the end of the pattern (to test the error).
2635
2636 4. Added the convenience functions for extracting substrings after a successful
2637 match. Updated pcretest to make it able to test these functions.
2638
2639
2640 Version 2.02 14-Jan-99
2641 ----------------------
2642
2643 1. Initialized the working variables associated with each extraction so that
2644 their saving and restoring doesn't refer to uninitialized store.
2645
2646 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2647 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2648 fix the problem.
2649
2650 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2651 calls, and wasn't printing the correct value for compiling calls. Increased the
2652 default value of LOOPREPEAT, and the number of significant figures in the
2653 times.
2654
2655 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2656
2657 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2658 a building problem on Windows NT with a FAT file system.
2659
2660
2661 Version 2.01 21-Oct-98
2662 ----------------------
2663
2664 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2665 to character tables built by pcre_maketables() in the current locale. If NULL
2666 is passed, the default tables are used.
2667
2668
2669 Version 2.00 24-Sep-98
2670 ----------------------
2671
2672 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2673 it any more.
2674
2675 2. Allow quantification of (?>) groups, and make it work correctly.
2676
2677 3. The first character computation wasn't working for (?>) groups.
2678
2679 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2680 end of the subject) and add 5.005's \z, which really does match only at the
2681 very end of the subject.
2682
2683 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2684
2685 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2686 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2687 localized options. All options to pcre_study() were also removed.
2688
2689 7. Add other new features from 5.005:
2690
2691 $(?<= positive lookbehind
2692 $(?<! negative lookbehind
2693 (?imsx-imsx) added the unsetting capability
2694 such a setting is global if at outer level; local otherwise
2695 (?imsx-imsx:) non-capturing groups with option setting
2696 (?(cond)re|re) conditional pattern matching
2697
2698 A backreference to itself in a repeated group matches the previous
2699 captured string.
2700
2701 8. General tidying up of studying (both automatic and via "study")
2702 consequential on the addition of new assertions.
2703
2704 9. As in 5.005, unlimited repeated groups that could match an empty substring
2705 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2706 runtime if any iteration does actually match an empty substring.
2707
2708 10. Include the RunTest script in the distribution.
2709
2710 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2711 discrepancies, some of which were old and were also with respect to 5.004. They
2712 have now been fixed.
2713
2714
2715 Version 1.09 28-Apr-98
2716 ----------------------
2717
2718 1. A negated single character class followed by a quantifier with a minimum
2719 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2720 program crashes, or just wrong answers. This did not apply to negated classes
2721 containing more than one character, or to minima other than one.
2722
2723
2724 Version 1.08 27-Mar-98
2725 ----------------------
2726
2727 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2728
2729 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2730 latter must appear before anything that relies on it in the pattern.
2731
2732
2733 Version 1.07 16-Feb-98
2734 ----------------------
2735
2736 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2737 repeat of a potentially empty string).
2738
2739
2740 Version 1.06 23-Jan-98
2741 ----------------------
2742
2743 1. Added Markus Oberhumer's little patches for C++.
2744
2745 2. Literal strings longer than 255 characters were broken.
2746
2747
2748 Version 1.05 23-Dec-97
2749 ----------------------
2750
2751 1. Negated character classes containing more than one character were failing if
2752 PCRE_CASELESS was set at run time.
2753
2754
2755 Version 1.04 19-Dec-97
2756 ----------------------
2757
2758 1. Corrected the man page, where some "const" qualifiers had been omitted.
2759
2760 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2761 input syntax.
2762
2763 3. Fixed memory leak which occurred when a regex with back references was
2764 matched with an offsets vector that wasn't big enough. The temporary memory
2765 that is used in this case wasn't being freed if the match failed.
2766
2767 4. Tidied pcretest to ensure it frees memory that it gets.
2768
2769 5. Temporary memory was being obtained in the case where the passed offsets
2770 vector was exactly big enough.
2771
2772 6. Corrected definition of offsetof() from change 5 below.
2773
2774 7. I had screwed up change 6 below and broken the rules for the use of
2775 setjmp(). Now fixed.
2776
2777
2778 Version 1.03 18-Dec-97
2779 ----------------------
2780
2781 1. A erroneous regex with a missing opening parenthesis was correctly
2782 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2783 on some systems.
2784
2785 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2786 it was reported that one broken compiler failed on the former because "code" is
2787 also an independent variable.
2788
2789 3. The erroneous regex a[]b caused an array overrun reference.
2790
2791 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2792 fail on data ending with that character. (It was going on too far, and checking
2793 the next character, typically a binary zero.) This was specific to the
2794 optimized code for single-character negative classes.
2795
2796 5. Added a contributed patch from the TIN world which does the following:
2797
2798 + Add an undef for memmove, in case the the system defines a macro for it.
2799
2800 + Add a definition of offsetof(), in case there isn't one. (I don't know
2801 the reason behind this - offsetof() is part of the ANSI standard - but
2802 it does no harm).
2803
2804 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2805 most of the places where whitespace preceded '#'. I have given up and
2806 allowed the remaining 2 cases to be at the margin.
2807
2808 + Rename some variables in pcre to eliminate shadowing. This seems very
2809 pedantic, but does no harm, of course.
2810
2811 6. Moved the call to setjmp() into its own function, to get rid of warnings
2812 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2813
2814 7. Constructs such as \d{8,} were compiling into the equivalent of
2815 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2816 outcome, but in this particular case used more store than had been allocated,
2817 which caused the bug to be discovered because it threw up an internal error.
2818
2819 8. The debugging code in both pcre and pcretest for outputting the compiled
2820 form of a regex was going wrong in the case of back references followed by
2821 curly-bracketed repeats.
2822
2823
2824 Version 1.02 12-Dec-97
2825 ----------------------
2826
2827 1. Typos in pcre.3 and comments in the source fixed.
2828
2829 2. Applied a contributed patch to get rid of places where it used to remove
2830 'const' from variables, and fixed some signed/unsigned and uninitialized
2831 variable warnings.
2832
2833 3. Added the "runtest" target to Makefile.
2834
2835 4. Set default compiler flag to -O2 rather than just -O.
2836
2837
2838 Version 1.01 19-Nov-97
2839 ----------------------
2840
2841 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2842 like /([ab]*)*/, that is, for classes with more than one character in them.
2843
2844 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2845 as /((?>a*))*/ (a PCRE_EXTRA facility).
2846
2847
2848 Version 1.00 18-Nov-97
2849 ----------------------
2850
2851 1. Added compile-time macros to support systems such as SunOS4 which don't have
2852 memmove() or strerror() but have other things that can be used instead.
2853
2854 2. Arranged that "make clean" removes the executables.
2855
2856
2857 Version 0.99 27-Oct-97
2858 ----------------------
2859
2860 1. Fixed bug in code for optimizing classes with only one character. It was
2861 initializing a 32-byte map regardless, which could cause it to run off the end
2862 of the memory it had got.
2863
2864 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2865
2866
2867 Version 0.98 22-Oct-97
2868 ----------------------
2869
2870 1. Fixed bug in code for handling temporary memory usage when there are more
2871 back references than supplied space in the ovector. This could cause segfaults.
2872
2873
2874 Version 0.97 21-Oct-97
2875 ----------------------
2876
2877 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2878
2879 2. Optimized negated single characters not to use a bit map.
2880
2881 3. Brought error texts together as macro definitions; clarified some of them;
2882 fixed one that was wrong - it said "range out of order" when it meant "invalid
2883 escape sequence".
2884
2885 4. Changed some char * arguments to const char *.
2886
2887 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2888
2889 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2890 pcretest.
2891
2892
2893 Version 0.96 16-Oct-97
2894 ----------------------
2895
2896 1. Added a simple "pgrep" utility to the distribution.
2897
2898 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2899 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2900 where "ddd" means "one or more decimal digits".
2901
2902 3. Fixed serious bug. If a pattern had a back reference, but the call to
2903 pcre_exec() didn't supply a large enough ovector to record the related
2904 identifying subpattern, the match always failed. PCRE now remembers the number
2905 of the largest back reference, and gets some temporary memory in which to save
2906 the offsets during matching if necessary, in order to ensure that
2907 backreferences always work.
2908
2909 4. Increased the compatibility with Perl in a number of ways:
2910
2911 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2912 to request this handling. The option can be set at compile or exec time.
2913
2914 (b) $ matches before a terminating newline by default; an option
2915 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2916 mode). The option can be set at compile or exec time.
2917
2918 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2919 the same as Perl's. If the decimal number it represents is less than 10
2920 or there aren't that many previous left capturing parentheses, an octal
2921 escape is read. Inside a character class, it's always an octal escape,
2922 even if it is a single digit.
2923
2924 (d) An escaped but undefined alphabetic character is taken as a literal,
2925 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2926 escapes.
2927
2928 (e) {0} is now permitted. (The previous item is removed from the compiled
2929 pattern).
2930
2931 5. Changed all the names of code files so that the basic parts are no longer
2932 than 10 characters, and abolished the teeny "globals.c" file.
2933
2934 6. Changed the handling of character classes; they are now done with a 32-byte
2935 bit map always.
2936
2937 7. Added the -d and /D options to pcretest to make it possible to look at the
2938 internals of compilation without having to recompile pcre.
2939
2940
2941 Version 0.95 23-Sep-97
2942 ----------------------
2943
2944 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2945 \x20 at the start of a run of normal characters. These were being treated as
2946 real characters, instead of the source characters being re-checked.
2947
2948
2949 Version 0.94 18-Sep-97
2950 ----------------------
2951
2952 1. The functions are now thread-safe, with the caveat that the global variables
2953 containing pointers to malloc() and free() or alternative functions are the
2954 same for all threads.
2955
2956 2. Get pcre_study() to generate a bitmap of initial characters for non-
2957 anchored patterns when this is possible, and use it if passed to pcre_exec().
2958
2959
2960 Version 0.93 15-Sep-97
2961 ----------------------
2962
2963 1. /(b)|(:+)/ was computing an incorrect first character.
2964
2965 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2966 but not actually doing anything yet.
2967
2968 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2969 as Perl does (e.g. [-az] or [az-]).
2970
2971 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2972 all possible positions.
2973
2974 5. Split up into different modules to avoid including unneeded functions in a
2975 compiled binary. However, compile and exec are still in one module. The "study"
2976 function is split off.
2977
2978 6. The character tables are now in a separate module whose source is generated
2979 by an auxiliary program - but can then be edited by hand if required. There are
2980 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2981 toupper() in the code.
2982
2983 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2984 make them global. Abolish the function for setting them, as the caller can now
2985 set them directly.
2986
2987
2988 Version 0.92 11-Sep-97
2989 ----------------------
2990
2991 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2992 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2993
2994 2. Caseless matching was not working in character classes if the characters in
2995 the pattern were in upper case.
2996
2997 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2998
2999 4. Make PCRE_ANCHORED public and accept as a compile option.
3000
3001 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3002 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3003 pass them.
3004
3005 6. Give an error if bad option bits passed at compile or run time.
3006
3007 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3008 pcretest to cause it to pass that flag.
3009
3010 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3011 options, and the first character, if set.
3012
3013 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3014
3015
3016 Version 0.91 10-Sep-97
3017 ----------------------
3018
3019 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3020 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3021
3022 2. PCRE was looping on encountering an indefinitely repeated back reference to
3023 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3024 Perl does - treats the match as successful.
3025
3026 ****

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