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Revision 71 - (show annotations) (download)
Sat Feb 24 21:40:24 2007 UTC (7 years, 5 months ago) by nigel
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Load pcre-4.4 into code/trunk.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 4.4 13-Aug-03
5 ---------------------
6
7 1. In UTF-8 mode, a character class containing characters with values between
8 127 and 255 was not handled correctly if the compiled pattern was studied.
9 In fixing this, I have also improved the studying algorithm for such
10 classes (slightly).
11
12 2. Three internal functions had redundant arguments passed to them. Removal
13 might give a very teeny performance improvement.
14
15 3. Documentation bug: the value of the capture_top field in a callout is *one
16 more than* the number of the hightest numbered captured substring.
17
18 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
19 in incorrectly linking with a previously installed version. They now link
20 explicitly with libpcre.la.
21
22 5. configure.in no longer needs to recognize Cygwin specially.
23
24 6. A problem in pcre.in for Windows platforms is fixed.
25
26 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
27 pcretest, it used to include the size of the study block as part of its
28 output. Unfortunately, the structure contains a field that has a different
29 size on different hardware architectures. This meant that the tests that
30 showed this size failed. As the block is currently always of a fixed size,
31 this information isn't actually particularly useful in pcretest output, so
32 I have just removed it.
33
34 8. Three pre-processor statements accidentally did not start in column 1.
35 Sadly, there are *still* compilers around that complain, even though
36 standard C has not required this for well over a decade. Sigh.
37
38 9. In pcretest, the code for checking callouts passed small integers in the
39 callout_data field, which is a void * field. However, some picky compilers
40 complained about the casts involved for this on 64-bit systems. Now
41 pcretest passes the address of the small integer instead, which should get
42 rid of the warnings.
43
44 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
45 both compile and run time, and gives an error if an invalid UTF-8 sequence
46 is found. There is a option for disabling this check in cases where the
47 string is known to be correct and/or the maximum performance is wanted.
48
49 11. In response to a bug report, I changed one line in Makefile.in from
50
51 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
52 to
53 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
54
55 to look similar to other lines, but I have no way of telling whether this
56 is the right thing to do, as I do not use Windows. No doubt I'll get told
57 if it's wrong...
58
59
60 Version 4.3 21-May-03
61 ---------------------
62
63 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
64 Makefile.
65
66 2. Some refactoring to improve the quality of the code:
67
68 (i) The utf8_table... variables are now declared "const".
69
70 (ii) The code for \cx, which used the "case flipping" table to upper case
71 lower case letters, now just substracts 32. This is ASCII-specific,
72 but the whole concept of \cx is ASCII-specific, so it seems
73 reasonable.
74
75 (iii) PCRE was using its character types table to recognize decimal and
76 hexadecimal digits in the pattern. This is silly, because it handles
77 only 0-9, a-f, and A-F, but the character types table is locale-
78 specific, which means strange things might happen. A private
79 table is now used for this - though it costs 256 bytes, a table is
80 much faster than multiple explicit tests. Of course, the standard
81 character types table is still used for matching digits in subject
82 strings against \d.
83
84 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
85 ending in _t are). So I've renamed it as ESC_tee.
86
87 3. The first argument for regexec() in the POSIX wrapper should have been
88 defined as "const".
89
90 4. Changed pcretest to use malloc() for its buffers so that they can be
91 Electric Fenced for debugging.
92
93 5. There were several places in the code where, in UTF-8 mode, PCRE would try
94 to read one or more bytes before the start of the subject string. Often this
95 had no effect on PCRE's behaviour, but in some circumstances it could
96 provoke a segmentation fault.
97
98 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
99 to try to read one or more bytes before the start of the subject string.
100
101 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
102 UTF-8 support could misbehave in various ways if the subject string
103 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
104 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
105 back over UTF-8 characters.)
106
107
108 Version 4.2 14-Apr-03
109 ---------------------
110
111 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
112
113 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
114 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
115 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
116 [WIN_PREFIX]: new variable, "cyg" for Cygwin
117 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
118 and BUILD_EXEEXT
119 Note: automatic setting of the BUILD variables is not yet working
120 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
121 compile-time but not at link-time
122 [LINK]: use for linking executables only
123 make different versions for Windows and non-Windows
124 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
125 libraries
126 [LINK_FOR_BUILD]: new variable
127 [OBJEXT]: use throughout
128 [EXEEXT]: use throughout
129 <winshared>: new target
130 <wininstall>: new target
131 <dftables.o>: use native compiler
132 <dftables>: use native linker
133 <install>: handle Windows platform correctly
134 <clean>: ditto
135 <check>: ditto
136 copy DLL to top builddir before testing
137
138 As part of these changes, -no-undefined was removed again. This was reported
139 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
140 in any case.
141
142 3. Some tidies to get rid of compiler warnings:
143
144 . In the match_data structure, match_limit was an unsigned long int, whereas
145 match_call_count was an int. I've made them both unsigned long ints.
146
147 . In pcretest the fact that a const uschar * doesn't automatically cast to
148 a void * provoked a warning.
149
150 . Turning on some more compiler warnings threw up some "shadow" variables
151 and a few more missing casts.
152
153 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
154 option, a class that contained a single character with a value between 128
155 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
156
157 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
158 option, a class that contained several characters, but with at least one
159 whose value was between 128 and 255 caused PCRE to crash.
160
161
162 Version 4.1 12-Mar-03
163 ---------------------
164
165 1. Compiling with gcc -pedantic found a couple of places where casts were
166 needed, and a string in dftables.c that was longer than standard compilers are
167 required to support.
168
169 2. Compiling with Sun's compiler found a few more places where the code could
170 be tidied up in order to avoid warnings.
171
172 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
173 first of these names is deprecated in the latest Autoconf in favour of the name
174 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
175 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
176 analogy I have changed it to CFLAGS_FOR_BUILD.
177
178 4. Added -no-undefined to the linking command in the Makefile, because this is
179 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
180 linking step for the pcreposix library.
181
182 5. PCRE was failing to diagnose the case of two named groups with the same
183 name.
184
185 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
186 literal character that is needed in the subject for a match, and scans along to
187 ensure that it is present before embarking on the full matching process. This
188 saves time in cases of nested unlimited repeats that are never going to match.
189 Problem: the scan can take a lot of time if the subject is very long (e.g.
190 megabytes), thus penalizing straightforward matches. It is now done only if the
191 amount of subject to be scanned is less than 1000 bytes.
192
193 7. A lesser problem with the same optimization is that it was recording the
194 first character of an anchored pattern as "needed", thus provoking a search
195 right along the subject, even when the first match of the pattern was going to
196 fail. The "needed" character is now not set for anchored patterns, unless it
197 follows something in the pattern that is of non-fixed length. Thus, it still
198 fulfils its original purpose of finding quick non-matches in cases of nested
199 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
200
201
202 Version 4.0 17-Feb-03
203 ---------------------
204
205 1. If a comment in an extended regex that started immediately after a meta-item
206 extended to the end of string, PCRE compiled incorrect data. This could lead to
207 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
208
209 2. Moved to autoconf 2.53 and libtool 1.4.2.
210
211 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
212 the special perltest8 script is no longer needed - all the tests can be run
213 from a single perltest script.
214
215 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
216 by \s. It has now been removed in PCRE. This means it isn't recognized as
217 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
218 class [:space:] *does* include VT, thereby creating a mess.
219
220 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
221 space and tab.
222
223 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
224 its new features into the main test script, reducing the number of scripts.
225
226 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
227 were backward compatible, and made the (?i) apply to the whole pattern, as if
228 /i were given. Now it behaves more logically, and applies the option setting
229 only to what follows. PCRE has been changed to follow suit. However, if it
230 finds options settings right at the start of the pattern, it extracts them into
231 the global options, as before. Thus, they show up in the info data.
232
233 8. Added support for the \Q...\E escape sequence. Characters in between are
234 treated as literals. This is slightly different from Perl in that $ and @ are
235 also handled as literals inside the quotes. In Perl, they will cause variable
236 interpolation. Note the following examples:
237
238 Pattern PCRE matches Perl matches
239
240 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
241 \Qabc\$xyz\E abc\$xyz abc\$xyz
242 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
243
244 For compatibility with Perl, \Q...\E sequences are recognized inside character
245 classes as well as outside them.
246
247 9. Re-organized 3 code statements in pcretest to avoid "overflow in
248 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
249 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
250 signed/unsigned warnings.
251
252 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
253 option for pcretest, so I've replaced it by a simple function that does just
254 that job.
255
256 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
257 "pcregrep -".
258
259 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
260 Java package. This provides some syntactic sugar for simple cases of what my
261 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
262 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
263 item, you can use this simplified notation. Note that only makes sense with
264 greedy quantifiers. Consequently, the use of the possessive quantifier forces
265 greediness, whatever the setting of the PCRE_UNGREEDY option.
266
267 13. A change of greediness default within a pattern was not taking effect at
268 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
269 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
270 was abstracted outside.
271
272 14. PCRE now supports the \G assertion. It is true when the current matching
273 position is at the start point of the match. This differs from \A when the
274 starting offset is non-zero. Used with the /g option of pcretest (or similar
275 code), it works in the same way as it does for Perl's /g option. If all
276 alternatives of a regex begin with \G, the expression is anchored to the start
277 match position, and the "anchored" flag is set in the compiled expression.
278
279 15. Some bugs concerning the handling of certain option changes within patterns
280 have been fixed. These applied to options other than (?ims). For example,
281 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
282 been the other way round. Some of this was related to change 7 above.
283
284 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
285 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
286 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
287 POSIX classes only within a class (e.g. /[[:alpha:]]/).
288
289 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
290 mode. Unlike ".", it always matches newline, whatever the setting of
291 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
292 assertions. Perl allows it, but it doesn't (in general) work because it can't
293 calculate the length of the lookbehind. At least, that's the case for Perl
294 5.8.0 - I've been told they are going to document that it doesn't work in
295 future.
296
297 18. Added an error diagnosis for escapes that PCRE does not support: these are
298 \L, \l, \N, \P, \p, \U, \u, and \X.
299
300 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
301 reading past the end of the pattern in cases such as /[abcd/.
302
303 20. PCRE was getting more memory than necessary for patterns with classes that
304 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
305
306 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
307 compiling PCRE for use with Virtual Pascal.
308
309 22. Small fix to the Makefile to make it work properly if the build is done
310 outside the source tree.
311
312 23. Added a new extension: a condition to go with recursion. If a conditional
313 subpattern starts with (?(R) the "true" branch is used if recursion has
314 happened, whereas the "false" branch is used only at the top level.
315
316 24. When there was a very long string of literal characters (over 255 bytes
317 without UTF support, over 250 bytes with UTF support), the computation of how
318 much memory was required could be incorrect, leading to segfaults or other
319 strange effects.
320
321 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
322 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
323 there was a subsequent back reference to those brackets. This meant that, for
324 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
325 possible to check for precisely this case. All we can do is abandon the
326 optimization if .* occurs inside capturing brackets when there are any back
327 references whatsoever. (See below for a better fix that came later.)
328
329 26. The handling of the optimization for finding the first character of a
330 non-anchored pattern, and for finding a character that is required later in the
331 match were failing in some cases. This didn't break the matching; it just
332 failed to optimize when it could. The way this is done has been re-implemented.
333
334 27. Fixed typo in error message for invalid (?R item (it said "(?p").
335
336 28. Added a new feature that provides some of the functionality that Perl
337 provides with (?{...}). The facility is termed a "callout". The way it is done
338 in PCRE is for the caller to provide an optional function, by setting
339 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
340 global variable. By default it is unset, which disables all calling out. To get
341 the function called, the regex must include (?C) at appropriate points. This
342 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
343 This provides a means of identifying different callout points. When PCRE
344 reaches such a point in the regex, if pcre_callout has been set, the external
345 function is called. It is provided with data in a structure called
346 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
347 matching continues; if it returns a non-zero value, the match at the current
348 point fails. However, backtracking will occur if possible. [This was changed
349 later and other features added - see item 49 below.]
350
351 29. pcretest is upgraded to test the callout functionality. It provides a
352 callout function that displays information. By default, it shows the start of
353 the match and the current position in the text. There are some new data escapes
354 to vary what happens:
355
356 \C+ in addition, show current contents of captured substrings
357 \C- do not supply a callout function
358 \C!n return 1 when callout number n is reached
359 \C!n!m return 1 when callout number n is reached for the mth time
360
361 30. If pcregrep was called with the -l option and just a single file name, it
362 output "<stdin>" if a match was found, instead of the file name.
363
364 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
365 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
366 pcre_exec(). This saves a malloc/free per call. The default value of
367 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
368 when configuring.
369
370 32. The default maximum size of a compiled pattern is 64K. There have been a
371 few cases of people hitting this limit. The code now uses macros to handle the
372 storing of links as offsets within the compiled pattern. It defaults to 2-byte
373 links, but this can be changed to 3 or 4 bytes by --with-link-size when
374 configuring. Tests 2 and 5 work only with 2-byte links because they output
375 debugging information about compiled patterns.
376
377 33. Internal code re-arrangements:
378
379 (a) Moved the debugging function for printing out a compiled regex into
380 its own source file (printint.c) and used #include to pull it into
381 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
382 separate copies.
383
384 (b) Defined the list of op-code names for debugging as a macro in
385 internal.h so that it is next to the definition of the opcodes.
386
387 (c) Defined a table of op-code lengths for simpler skipping along compiled
388 code. This is again a macro in internal.h so that it is next to the
389 definition of the opcodes.
390
391 34. Added support for recursive calls to individual subpatterns, along the
392 lines of Robin Houston's patch (but implemented somewhat differently).
393
394 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
395 allow it to read and process whole directories in Win32. This code was
396 contributed by Lionel Fourquaux; it has not been tested by me.
397
398 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
399 used to name a group. Names consist of alphanumerics and underscores, and must
400 be unique. Back references use the syntax (?P=name) and recursive calls use
401 (?P>name) which is a PCRE extension to the Python extension. Groups still have
402 numbers. The function pcre_fullinfo() can be used after compilation to extract
403 a name/number map. There are three relevant calls:
404
405 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
406 PCRE_INFO_NAMECOUNT yields the number of entries
407 PCRE_INFO_NAMETABLE yields a pointer to the map.
408
409 The map is a vector of fixed-size entries. The size of each entry depends on
410 the length of the longest name used. The first two bytes of each entry are the
411 group number, most significant byte first. There follows the corresponding
412 name, zero terminated. The names are in alphabetical order.
413
414 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
415 case instead of 255. Making it the same both with and without UTF-8 support
416 means that the same test output works with both.
417
418 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
419 calling malloc() with a zero argument.
420
421 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
422 optimization. I've improved things by keeping a bitmap of backreferences with
423 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
424 fact referenced, the optimization can be applied. It is unlikely that a
425 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
426 the match to follow \n) will appear inside brackets with a number greater than
427 31, but if it does, any back reference > 31 suppresses the optimization.
428
429 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
430 of disabling numbered capturing parentheses. Any opening parenthesis that is
431 not followed by ? behaves as if it were followed by ?: but named parentheses
432 can still be used for capturing (and they will acquire numbers in the usual
433 way).
434
435 41. Redesigned the return codes from the match() function into yes/no/error so
436 that errors can be passed back from deep inside the nested calls. A malloc
437 failure while inside a recursive subpattern call now causes the
438 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
439
440 42. It is now possible to set a limit on the number of times the match()
441 function is called in a call to pcre_exec(). This facility makes it possible to
442 limit the amount of recursion and backtracking, though not in a directly
443 obvious way, because the match() function is used in a number of different
444 circumstances. The count starts from zero for each position in the subject
445 string (for non-anchored patterns). The default limit is, for compatibility, a
446 large number, namely 10 000 000. You can change this in two ways:
447
448 (a) When configuring PCRE before making, you can use --with-match-limit=n
449 to set a default value for the compiled library.
450
451 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
452 a different value is set. See 45 below.
453
454 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
455
456 43. Added a new function pcre_config(int, void *) to enable run-time extraction
457 of things that can be changed at compile time. The first argument specifies
458 what is wanted and the second points to where the information is to be placed.
459 The current list of available information is:
460
461 PCRE_CONFIG_UTF8
462
463 The output is an integer that is set to one if UTF-8 support is available;
464 otherwise it is set to zero.
465
466 PCRE_CONFIG_NEWLINE
467
468 The output is an integer that it set to the value of the code that is used for
469 newline. It is either LF (10) or CR (13).
470
471 PCRE_CONFIG_LINK_SIZE
472
473 The output is an integer that contains the number of bytes used for internal
474 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
475
476 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
477
478 The output is an integer that contains the threshold above which the POSIX
479 interface uses malloc() for output vectors. See item 31 above.
480
481 PCRE_CONFIG_MATCH_LIMIT
482
483 The output is an unsigned integer that contains the default limit of the number
484 of match() calls in a pcre_exec() execution. See 42 above.
485
486 44. pcretest has been upgraded by the addition of the -C option. This causes it
487 to extract all the available output from the new pcre_config() function, and to
488 output it. The program then exits immediately.
489
490 45. A need has arisen to pass over additional data with calls to pcre_exec() in
491 order to support additional features. One way would have been to define
492 pcre_exec2() (for example) with extra arguments, but this would not have been
493 extensible, and would also have required all calls to the original function to
494 be mapped to the new one. Instead, I have chosen to extend the mechanism that
495 is used for passing in "extra" data from pcre_study().
496
497 The pcre_extra structure is now exposed and defined in pcre.h. It currently
498 contains the following fields:
499
500 flags a bitmap indicating which of the following fields are set
501 study_data opaque data from pcre_study()
502 match_limit a way of specifying a limit on match() calls for a specific
503 call to pcre_exec()
504 callout_data data for callouts (see 49 below)
505
506 The flag bits are also defined in pcre.h, and are
507
508 PCRE_EXTRA_STUDY_DATA
509 PCRE_EXTRA_MATCH_LIMIT
510 PCRE_EXTRA_CALLOUT_DATA
511
512 The pcre_study() function now returns one of these new pcre_extra blocks, with
513 the actual study data pointed to by the study_data field, and the
514 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
515 before. That is, this change is entirely upwards-compatible and requires no
516 change to existing code.
517
518 If you want to pass in additional data to pcre_exec(), you can either place it
519 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
520 block.
521
522 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
523 data string contains the escape sequence \M, pcretest calls pcre_exec() several
524 times with different match limits, until it finds the minimum value needed for
525 pcre_exec() to complete. The value is then output. This can be instructive; for
526 most simple matches the number is quite small, but for pathological cases it
527 gets very large very quickly.
528
529 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
530 returns the size of the data block pointed to by the study_data field in a
531 pcre_extra block, that is, the value that was passed as the argument to
532 pcre_malloc() when PCRE was getting memory in which to place the information
533 created by pcre_study(). The fourth argument should point to a size_t variable.
534 pcretest has been extended so that this information is shown after a successful
535 pcre_study() call when information about the compiled regex is being displayed.
536
537 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
538 because what follows is always an absolute path. (Later: it turns out that this
539 is more than cosmetic for MinGW, because it doesn't like empty path
540 components.)
541
542 49. Some changes have been made to the callout feature (see 28 above):
543
544 (i) A callout function now has three choices for what it returns:
545
546 0 => success, carry on matching
547 > 0 => failure at this point, but backtrack if possible
548 < 0 => serious error, return this value from pcre_exec()
549
550 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
551 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
552 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
553 use by callout functions. It will never be used by PCRE itself.
554
555 (ii) The pcre_extra structure (see 45 above) has a void * field called
556 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
557 pcre_callout_block structure has a field of the same name. The contents of
558 the field passed in the pcre_extra structure are passed to the callout
559 function in the corresponding field in the callout block. This makes it
560 easier to use the same callout-containing regex from multiple threads. For
561 testing, the pcretest program has a new data escape
562
563 \C*n pass the number n (may be negative) as callout_data
564
565 If the callout function in pcretest receives a non-zero value as
566 callout_data, it returns that value.
567
568 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
569 there were some redundant $(CFLAGS) in commands that are now specified as
570 $(LINK), which already includes $(CFLAGS).
571
572 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
573 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
574 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
575 one-byte characters throughout. Note that case-insensitive matching applies
576 only to characters whose values are less than 256. PCRE doesn't support the
577 notion of cases for higher-valued characters.
578
579 (i) A character class whose characters are all within 0-255 is handled as
580 a bit map, and the map is inverted for negative classes. Previously, a
581 character > 255 always failed to match such a class; however it should
582 match if the class was a negative one (e.g. [^ab]). This has been fixed.
583
584 (ii) A negated character class with a single character < 255 is coded as
585 "not this character" (OP_NOT). This wasn't working properly when the test
586 character was multibyte, either singly or repeated.
587
588 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
589 mode, for example: \x{100}{2,3}.
590
591 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
592 singly or repeated) now correctly test multibyte characters. However,
593 PCRE doesn't recognize any characters with values greater than 255 as
594 digits, spaces, or word characters. Such characters always match \D, \S,
595 and \W, and never match \d, \s, or \w.
596
597 (v) Classes may now contain characters and character ranges with values
598 greater than 255. For example: [ab\x{100}-\x{400}].
599
600 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
601 PCRE in UTF-8 mode.
602
603 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
604 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
605 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
606 value.)
607
608 53. The single man page has become too large. I have therefore split it up into
609 a number of separate man pages. These also give rise to individual HTML pages;
610 these are now put in a separate directory, and there is an index.html page that
611 lists them all. Some hyperlinking between the pages has been installed.
612
613 54. Added convenience functions for handling named capturing parentheses.
614
615 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
616 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
617 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
618 are faulted.
619
620 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
621 calling configure. These values are used when compiling the dftables.c program
622 which is run to generate the source of the default character tables. They
623 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
624 you will need to set these values.
625
626 57. Updated the building process for Windows DLL, as provided by Fred Cox.
627
628
629 Version 3.9 02-Jan-02
630 ---------------------
631
632 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
633
634 2. If --disable-static was given, the building process failed when trying to
635 build pcretest and pcregrep. (For some reason it was using libtool to compile
636 them, which is not right, as they aren't part of the library.)
637
638
639 Version 3.8 18-Dec-01
640 ---------------------
641
642 1. The experimental UTF-8 code was completely screwed up. It was packing the
643 bytes in the wrong order. How dumb can you get?
644
645
646 Version 3.7 29-Oct-01
647 ---------------------
648
649 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
650 This caused pcretest, when used on the test data, to segfault. Unfortunately,
651 this didn't happen under Solaris 8, where I normally test things.
652
653 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
654 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
655 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
656 this fix an hour or so after the initial 3.7 release.)
657
658
659 Version 3.6 23-Oct-01
660 ---------------------
661
662 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
663 offsets passed as NULL with zero offset count.
664
665 2. The config.guess and config.sub files had not been updated when I moved to
666 the latest autoconf.
667
668
669 Version 3.5 15-Aug-01
670 ---------------------
671
672 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
673 had been forgotten.
674
675 2. By using declared but undefined structures, we can avoid using "void"
676 definitions in pcre.h while keeping the internal definitions of the structures
677 private.
678
679 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
680 user point of view, this means that both static and shared libraries are built
681 by default, but this can be individually controlled. More of the work of
682 handling this static/shared cases is now inside libtool instead of PCRE's make
683 file.
684
685 4. The pcretest utility is now installed along with pcregrep because it is
686 useful for users (to test regexs) and by doing this, it automatically gets
687 relinked by libtool. The documentation has been turned into a man page, so
688 there are now .1, .txt, and .html versions in /doc.
689
690 5. Upgrades to pcregrep:
691 (i) Added long-form option names like gnu grep.
692 (ii) Added --help to list all options with an explanatory phrase.
693 (iii) Added -r, --recursive to recurse into sub-directories.
694 (iv) Added -f, --file to read patterns from a file.
695
696 6. pcre_exec() was referring to its "code" argument before testing that
697 argument for NULL (and giving an error if it was NULL).
698
699 7. Upgraded Makefile.in to allow for compiling in a different directory from
700 the source directory.
701
702 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
703 options bits, the pointer it was passed was to an int instead of to an unsigned
704 long int. This mattered only on 64-bit systems.
705
706 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
707 generated) instead of pcre.in, which it its source. Also made the same change
708 in several of the .c files.
709
710 10. A new release of gcc defines printf() as a macro, which broke pcretest
711 because it had an ifdef in the middle of a string argument for printf(). Fixed
712 by using separate calls to printf().
713
714 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
715 script, to force use of CR or LF instead of \n in the source. On non-Unix
716 systems, the value can be set in config.h.
717
718 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
719 absolute limit. Changed the text of the error message to make this clear, and
720 likewise updated the man page.
721
722 13. The limit of 99 on the number of capturing subpatterns has been removed.
723 The new limit is 65535, which I hope will not be a "real" limit.
724
725
726 Version 3.4 22-Aug-00
727 ---------------------
728
729 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
730
731 2. Diagnose condition (?(0) as an error instead of crashing on matching.
732
733
734 Version 3.3 01-Aug-00
735 ---------------------
736
737 1. If an octal character was given, but the value was greater than \377, it
738 was not getting masked to the least significant bits, as documented. This could
739 lead to crashes in some systems.
740
741 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
742 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
743
744 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
745 These just pass their arguments on to (pcre_free)(), but they are provided
746 because some uses of PCRE bind it to non-C systems that can call its functions,
747 but cannot call free() or pcre_free() directly.
748
749 4. Add "make test" as a synonym for "make check". Corrected some comments in
750 the Makefile.
751
752 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
753 Makefile.
754
755 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
756 command called pgrep for grepping around the active processes.
757
758 7. Added the beginnings of support for UTF-8 character strings.
759
760 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
761 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
762 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
763 out for the ar command.)
764
765
766 Version 3.2 12-May-00
767 ---------------------
768
769 This is purely a bug fixing release.
770
771 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
772 of ZA. This was just one example of several cases that could provoke this bug,
773 which was introduced by change 9 of version 2.00. The code for breaking
774 infinite loops after an iteration that matches an empty string was't working
775 correctly.
776
777 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
778 when matched against abbab (for example). After matching an empty string, it
779 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
780 caused it to match further down the string than it should.
781
782 3. The code contained an inclusion of sys/types.h. It isn't clear why this
783 was there because it doesn't seem to be needed, and it causes trouble on some
784 systems, as it is not a Standard C header. It has been removed.
785
786 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
787 were reported on the Macintosh. The changes were from
788
789 while ((c = *(++ptr)) != 0 && c != '\n');
790 to
791 while ((c = *(++ptr)) != 0 && c != '\n') ;
792
793 Totally extraordinary, but if that's what it takes...
794
795 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
796 available. Added HAVE_BCOPY and an autoconf test for it; if neither
797 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
798 assumes the way PCRE uses memmove() (always moving upwards).
799
800 6. PCRE is being used in one environment where strchr() is not available. There
801 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
802 faster code anyway.
803
804
805 Version 3.1 09-Feb-00
806 ---------------------
807
808 The only change in this release is the fixing of some bugs in Makefile.in for
809 the "install" target:
810
811 (1) It was failing to install pcreposix.h.
812
813 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
814
815
816 Version 3.0 01-Feb-00
817 ---------------------
818
819 1. Add support for the /+ modifier to perltest (to output $` like it does in
820 pcretest).
821
822 2. Add support for the /g modifier to perltest.
823
824 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
825 matches null strings.
826
827 4. Fix perltest so that it doesn't do unwanted things when fed an empty
828 pattern. Perl treats empty patterns specially - it reuses the most recent
829 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
830 effect.
831
832 5. The POSIX interface was broken in that it was just handing over the POSIX
833 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
834 required a bigger vector, with some working space on the end. This means that
835 the POSIX wrapper now has to get and free some memory, and copy the results.
836
837 6. Added some simple autoconf support, placing the test data and the
838 documentation in separate directories, re-organizing some of the
839 information files, and making it build pcre-config (a GNU standard). Also added
840 libtool support for building PCRE as a shared library, which is now the
841 default.
842
843 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
844 09 are not valid octal constants. Single digits will be used for minor values
845 less than 10.
846
847 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
848 existing programs that set these in the POSIX interface can use PCRE without
849 modification.
850
851 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
852 return all that pcre_info() returns, plus additional data. The pcre_info()
853 function is retained for compatibility, but is considered to be obsolete.
854
855 10. Added experimental recursion feature (?R) to handle one common case that
856 Perl 5.6 will be able to do with (?p{...}).
857
858 11. Added support for POSIX character classes like [:alpha:], which Perl is
859 adopting.
860
861
862 Version 2.08 31-Aug-99
863 ----------------------
864
865 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
866 trying to match at the startoffset position, but instead was moving forward to
867 the next newline as if a previous match had failed.
868
869 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
870 and could get into a loop if a null string was matched other than at the start
871 of the subject.
872
873 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
874 be distinguished at compile time, and for completeness also added PCRE_DATE.
875
876 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
877 in GnuWin32 environments.
878
879
880 Version 2.07 29-Jul-99
881 ----------------------
882
883 1. The documentation is now supplied in plain text form and HTML as well as in
884 the form of man page sources.
885
886 2. C++ compilers don't like assigning (void *) values to other pointer types.
887 In particular this affects malloc(). Although there is no problem in Standard
888 C, I've put in casts to keep C++ compilers happy.
889
890 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
891 should be (const char *).
892
893 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
894 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
895 However, I haven't made this a standard facility. The documentation doesn't
896 mention it, and the Makefile doesn't support it.
897
898 5. The Makefile now contains an "install" target, with editable destinations at
899 the top of the file. The pcretest program is not installed.
900
901 6. pgrep -V now gives the PCRE version number and date.
902
903 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
904 causing the entire string to be ignored, instead of just the last character.
905
906 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
907 non-matching string, it can take a very, very long time, even for strings of
908 quite modest length, because of the nested recursion. PCRE now does better in
909 some of these cases. It does this by remembering the last required literal
910 character in the pattern, and pre-searching the subject to ensure it is present
911 before running the real match. In other words, it applies a heuristic to detect
912 some types of certain failure quickly, and in the above example, if presented
913 with a string that has no trailing " it gives "no match" very quickly.
914
915 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
916 other alternatives are tried instead.
917
918
919 Version 2.06 09-Jun-99
920 ----------------------
921
922 1. Change pcretest's output for amount of store used to show just the code
923 space, because the remainder (the data block) varies in size between 32-bit and
924 64-bit systems.
925
926 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
927 start matching at. This allows lookbehinds to work when searching for multiple
928 occurrences in a string.
929
930 3. Added additional options to pcretest for testing multiple occurrences:
931
932 /+ outputs the rest of the string that follows a match
933 /g loops for multiple occurrences, using the new startoffset argument
934 /G loops for multiple occurrences by passing an incremented pointer
935
936 4. PCRE wasn't doing the "first character" optimization for patterns starting
937 with \b or \B, though it was doing it for other lookbehind assertions. That is,
938 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
939 the letter 'x'. On long subject strings, this gives a significant speed-up.
940
941
942 Version 2.05 21-Apr-99
943 ----------------------
944
945 1. Changed the type of magic_number from int to long int so that it works
946 properly on 16-bit systems.
947
948 2. Fixed a bug which caused patterns starting with .* not to work correctly
949 when the subject string contained newline characters. PCRE was assuming
950 anchoring for such patterns in all cases, which is not correct because .* will
951 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
952 DOTALL is set at top level; otherwise it knows that patterns starting with .*
953 must be retried after every newline in the subject.
954
955
956 Version 2.04 18-Feb-99
957 ----------------------
958
959 1. For parenthesized subpatterns with repeats whose minimum was zero, the
960 computation of the store needed to hold the pattern was incorrect (too large).
961 If such patterns were nested a few deep, this could multiply and become a real
962 problem.
963
964 2. Added /M option to pcretest to show the memory requirement of a specific
965 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
966
967 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
968 compiled in such a way that the backtracking after subsequent failure was
969 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
970 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
971
972
973 Version 2.03 02-Feb-99
974 ----------------------
975
976 1. Fixed typo and small mistake in man page.
977
978 2. Added 4th condition (GPL supersedes if conflict) and created separate
979 LICENCE file containing the conditions.
980
981 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
982 Perl, that is the internal \ allows the delimiter to be included in the
983 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
984 the final delimiter, add \ to the end of the pattern (to test the error).
985
986 4. Added the convenience functions for extracting substrings after a successful
987 match. Updated pcretest to make it able to test these functions.
988
989
990 Version 2.02 14-Jan-99
991 ----------------------
992
993 1. Initialized the working variables associated with each extraction so that
994 their saving and restoring doesn't refer to uninitialized store.
995
996 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
997 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
998 fix the problem.
999
1000 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
1001 calls, and wasn't printing the correct value for compiling calls. Increased the
1002 default value of LOOPREPEAT, and the number of significant figures in the
1003 times.
1004
1005 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
1006
1007 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
1008 a building problem on Windows NT with a FAT file system.
1009
1010
1011 Version 2.01 21-Oct-98
1012 ----------------------
1013
1014 1. Changed the API for pcre_compile() to allow for the provision of a pointer
1015 to character tables built by pcre_maketables() in the current locale. If NULL
1016 is passed, the default tables are used.
1017
1018
1019 Version 2.00 24-Sep-98
1020 ----------------------
1021
1022 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
1023 it any more.
1024
1025 2. Allow quantification of (?>) groups, and make it work correctly.
1026
1027 3. The first character computation wasn't working for (?>) groups.
1028
1029 4. Correct the implementation of \Z (it is permitted to match on the \n at the
1030 end of the subject) and add 5.005's \z, which really does match only at the
1031 very end of the subject.
1032
1033 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
1034
1035 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
1036 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
1037 localized options. All options to pcre_study() were also removed.
1038
1039 7. Add other new features from 5.005:
1040
1041 $(?<= positive lookbehind
1042 $(?<! negative lookbehind
1043 (?imsx-imsx) added the unsetting capability
1044 such a setting is global if at outer level; local otherwise
1045 (?imsx-imsx:) non-capturing groups with option setting
1046 (?(cond)re|re) conditional pattern matching
1047
1048 A backreference to itself in a repeated group matches the previous
1049 captured string.
1050
1051 8. General tidying up of studying (both automatic and via "study")
1052 consequential on the addition of new assertions.
1053
1054 9. As in 5.005, unlimited repeated groups that could match an empty substring
1055 are no longer faulted at compile time. Instead, the loop is forcibly broken at
1056 runtime if any iteration does actually match an empty substring.
1057
1058 10. Include the RunTest script in the distribution.
1059
1060 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
1061 discrepancies, some of which were old and were also with respect to 5.004. They
1062 have now been fixed.
1063
1064
1065 Version 1.09 28-Apr-98
1066 ----------------------
1067
1068 1. A negated single character class followed by a quantifier with a minimum
1069 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
1070 program crashes, or just wrong answers. This did not apply to negated classes
1071 containing more than one character, or to minima other than one.
1072
1073
1074 Version 1.08 27-Mar-98
1075 ----------------------
1076
1077 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
1078
1079 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
1080 latter must appear before anything that relies on it in the pattern.
1081
1082
1083 Version 1.07 16-Feb-98
1084 ----------------------
1085
1086 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
1087 repeat of a potentially empty string).
1088
1089
1090 Version 1.06 23-Jan-98
1091 ----------------------
1092
1093 1. Added Markus Oberhumer's little patches for C++.
1094
1095 2. Literal strings longer than 255 characters were broken.
1096
1097
1098 Version 1.05 23-Dec-97
1099 ----------------------
1100
1101 1. Negated character classes containing more than one character were failing if
1102 PCRE_CASELESS was set at run time.
1103
1104
1105 Version 1.04 19-Dec-97
1106 ----------------------
1107
1108 1. Corrected the man page, where some "const" qualifiers had been omitted.
1109
1110 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
1111 input syntax.
1112
1113 3. Fixed memory leak which occurred when a regex with back references was
1114 matched with an offsets vector that wasn't big enough. The temporary memory
1115 that is used in this case wasn't being freed if the match failed.
1116
1117 4. Tidied pcretest to ensure it frees memory that it gets.
1118
1119 5. Temporary memory was being obtained in the case where the passed offsets
1120 vector was exactly big enough.
1121
1122 6. Corrected definition of offsetof() from change 5 below.
1123
1124 7. I had screwed up change 6 below and broken the rules for the use of
1125 setjmp(). Now fixed.
1126
1127
1128 Version 1.03 18-Dec-97
1129 ----------------------
1130
1131 1. A erroneous regex with a missing opening parenthesis was correctly
1132 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
1133 on some systems.
1134
1135 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
1136 it was reported that one broken compiler failed on the former because "code" is
1137 also an independent variable.
1138
1139 3. The erroneous regex a[]b caused an array overrun reference.
1140
1141 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
1142 fail on data ending with that character. (It was going on too far, and checking
1143 the next character, typically a binary zero.) This was specific to the
1144 optimized code for single-character negative classes.
1145
1146 5. Added a contributed patch from the TIN world which does the following:
1147
1148 + Add an undef for memmove, in case the the system defines a macro for it.
1149
1150 + Add a definition of offsetof(), in case there isn't one. (I don't know
1151 the reason behind this - offsetof() is part of the ANSI standard - but
1152 it does no harm).
1153
1154 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
1155 most of the places where whitespace preceded '#'. I have given up and
1156 allowed the remaining 2 cases to be at the margin.
1157
1158 + Rename some variables in pcre to eliminate shadowing. This seems very
1159 pedantic, but does no harm, of course.
1160
1161 6. Moved the call to setjmp() into its own function, to get rid of warnings
1162 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
1163
1164 7. Constructs such as \d{8,} were compiling into the equivalent of
1165 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
1166 outcome, but in this particular case used more store than had been allocated,
1167 which caused the bug to be discovered because it threw up an internal error.
1168
1169 8. The debugging code in both pcre and pcretest for outputting the compiled
1170 form of a regex was going wrong in the case of back references followed by
1171 curly-bracketed repeats.
1172
1173
1174 Version 1.02 12-Dec-97
1175 ----------------------
1176
1177 1. Typos in pcre.3 and comments in the source fixed.
1178
1179 2. Applied a contributed patch to get rid of places where it used to remove
1180 'const' from variables, and fixed some signed/unsigned and uninitialized
1181 variable warnings.
1182
1183 3. Added the "runtest" target to Makefile.
1184
1185 4. Set default compiler flag to -O2 rather than just -O.
1186
1187
1188 Version 1.01 19-Nov-97
1189 ----------------------
1190
1191 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
1192 like /([ab]*)*/, that is, for classes with more than one character in them.
1193
1194 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
1195 as /((?>a*))*/ (a PCRE_EXTRA facility).
1196
1197
1198 Version 1.00 18-Nov-97
1199 ----------------------
1200
1201 1. Added compile-time macros to support systems such as SunOS4 which don't have
1202 memmove() or strerror() but have other things that can be used instead.
1203
1204 2. Arranged that "make clean" removes the executables.
1205
1206
1207 Version 0.99 27-Oct-97
1208 ----------------------
1209
1210 1. Fixed bug in code for optimizing classes with only one character. It was
1211 initializing a 32-byte map regardless, which could cause it to run off the end
1212 of the memory it had got.
1213
1214 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
1215
1216
1217 Version 0.98 22-Oct-97
1218 ----------------------
1219
1220 1. Fixed bug in code for handling temporary memory usage when there are more
1221 back references than supplied space in the ovector. This could cause segfaults.
1222
1223
1224 Version 0.97 21-Oct-97
1225 ----------------------
1226
1227 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
1228
1229 2. Optimized negated single characters not to use a bit map.
1230
1231 3. Brought error texts together as macro definitions; clarified some of them;
1232 fixed one that was wrong - it said "range out of order" when it meant "invalid
1233 escape sequence".
1234
1235 4. Changed some char * arguments to const char *.
1236
1237 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
1238
1239 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
1240 pcretest.
1241
1242
1243 Version 0.96 16-Oct-97
1244 ----------------------
1245
1246 1. Added a simple "pgrep" utility to the distribution.
1247
1248 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
1249 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
1250 where "ddd" means "one or more decimal digits".
1251
1252 3. Fixed serious bug. If a pattern had a back reference, but the call to
1253 pcre_exec() didn't supply a large enough ovector to record the related
1254 identifying subpattern, the match always failed. PCRE now remembers the number
1255 of the largest back reference, and gets some temporary memory in which to save
1256 the offsets during matching if necessary, in order to ensure that
1257 backreferences always work.
1258
1259 4. Increased the compatibility with Perl in a number of ways:
1260
1261 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
1262 to request this handling. The option can be set at compile or exec time.
1263
1264 (b) $ matches before a terminating newline by default; an option
1265 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
1266 mode). The option can be set at compile or exec time.
1267
1268 (c) The handling of \ followed by a digit other than 0 is now supposed to be
1269 the same as Perl's. If the decimal number it represents is less than 10
1270 or there aren't that many previous left capturing parentheses, an octal
1271 escape is read. Inside a character class, it's always an octal escape,
1272 even if it is a single digit.
1273
1274 (d) An escaped but undefined alphabetic character is taken as a literal,
1275 unless PCRE_EXTRA is set. Currently this just reserves the remaining
1276 escapes.
1277
1278 (e) {0} is now permitted. (The previous item is removed from the compiled
1279 pattern).
1280
1281 5. Changed all the names of code files so that the basic parts are no longer
1282 than 10 characters, and abolished the teeny "globals.c" file.
1283
1284 6. Changed the handling of character classes; they are now done with a 32-byte
1285 bit map always.
1286
1287 7. Added the -d and /D options to pcretest to make it possible to look at the
1288 internals of compilation without having to recompile pcre.
1289
1290
1291 Version 0.95 23-Sep-97
1292 ----------------------
1293
1294 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
1295 \x20 at the start of a run of normal characters. These were being treated as
1296 real characters, instead of the source characters being re-checked.
1297
1298
1299 Version 0.94 18-Sep-97
1300 ----------------------
1301
1302 1. The functions are now thread-safe, with the caveat that the global variables
1303 containing pointers to malloc() and free() or alternative functions are the
1304 same for all threads.
1305
1306 2. Get pcre_study() to generate a bitmap of initial characters for non-
1307 anchored patterns when this is possible, and use it if passed to pcre_exec().
1308
1309
1310 Version 0.93 15-Sep-97
1311 ----------------------
1312
1313 1. /(b)|(:+)/ was computing an incorrect first character.
1314
1315 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
1316 but not actually doing anything yet.
1317
1318 3. Treat "-" characters in classes that cannot be part of ranges as literals,
1319 as Perl does (e.g. [-az] or [az-]).
1320
1321 4. Set the anchored flag if a branch starts with .* or .*? because that tests
1322 all possible positions.
1323
1324 5. Split up into different modules to avoid including unneeded functions in a
1325 compiled binary. However, compile and exec are still in one module. The "study"
1326 function is split off.
1327
1328 6. The character tables are now in a separate module whose source is generated
1329 by an auxiliary program - but can then be edited by hand if required. There are
1330 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
1331 toupper() in the code.
1332
1333 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
1334 make them global. Abolish the function for setting them, as the caller can now
1335 set them directly.
1336
1337
1338 Version 0.92 11-Sep-97
1339 ----------------------
1340
1341 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
1342 (e.g. /a{1,3}/) was broken (I mis-optimized it).
1343
1344 2. Caseless matching was not working in character classes if the characters in
1345 the pattern were in upper case.
1346
1347 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
1348
1349 4. Make PCRE_ANCHORED public and accept as a compile option.
1350
1351 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
1352 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
1353 pass them.
1354
1355 6. Give an error if bad option bits passed at compile or run time.
1356
1357 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
1358 pcretest to cause it to pass that flag.
1359
1360 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
1361 options, and the first character, if set.
1362
1363 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
1364
1365
1366 Version 0.91 10-Sep-97
1367 ----------------------
1368
1369 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
1370 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
1371
1372 2. PCRE was looping on encountering an indefinitely repeated back reference to
1373 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
1374 Perl does - treats the match as successful.
1375
1376 ****

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