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Revision 222 - (show annotations) (download)
Fri Aug 17 10:48:51 2007 UTC (7 years, 3 months ago) by ph10
File size: 137413 byte(s)
Fix pcregrep -Mv looping bug.

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

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