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Revision 357 - (hide annotations) (download)
Tue Jul 8 14:18:28 2008 UTC (6 years, 9 months ago) by ph10
File size: 157558 byte(s)
Added two (int) casts to pcregrep.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 349 Version 8.0 02 Jul-08
5     ---------------------
7     1. Replaced UCP searching code with optimized version as implemented for Ad
8     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
10     to 5 times on some simple patterns that I tested. Permission was given to
11     distribute the MultiStage2.py script that generates the tables (it's not in
12     the tarball, but is in the Subversion repository).
13 ph10 349
14 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15     scripts.
16 ph10 353
17     3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18     a group with a zero qualifier. The result of the study could be incorrect,
19     or the function might crash, depending on the pattern.
20 ph10 354
21     4. Caseless matching was not working for non-ASCII characters in back
22     references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23     It now works when Unicode Property Support is available.
24 ph10 355
25     5. In pcretest, an escape such as \x{de} in the data was always generating
26     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28     truncation.
29 ph10 356
30     6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
31 ph10 349
32 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
33     pointers, in case they are 64-bit values.
34 ph10 351
35 ph10 357
36 ph10 347 Version 7.7 07-May-08
37 ph10 321 ---------------------
39     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
40 ph10 345 a string to a long long, pretend we don't even have a long long." This is
41 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
42 ph10 345
43 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
44     pre-7.6 versions, which defined a global no_arg variable instead of putting
45 ph10 332 it in the RE class. (See also #8 below.)
46 ph10 345
47     3. Remove a line of dead code, identified by coverity and reported by Nuno
48     Lopes.
50 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
51 ph10 321
52 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
53 ph10 345 of files, instead of just to the final components.
55 ph10 324 (2) If there was more than one level of directory, the subdirectories were
56     skipped unless they satisfied the include/exclude conditions. This is
57     inconsistent with GNU grep (and could even be seen as contrary to the
58     pcregrep specification - which I improved to make it absolutely clear).
59     The action now is always to scan all levels of directory, and just
60     apply the include/exclude patterns to regular files.
61 ph10 345
62 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
63 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
65 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
66 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
67 ph10 326 doesn't support NULs in patterns.
68 ph10 345
69     7. Added some missing "const"s to declarations of static tables in
70     pcre_compile.c and pcre_dfa_exec.c.
72 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
73 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
74 ph10 345 first patch. And a third patch - this was a messy problem.)
75 ph10 321
76 ph10 345 9. Applied Craig's patch to remove the use of push_back().
78 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
79     matching function regexec().
80 ph10 345
81     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
82     which, however, unlike Perl's \g{...}, are subroutine calls, not back
83 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
84     Oniguruma does).
85 ph10 345
86     12. Previously, a group with a zero repeat such as (...){0} was completely
87 ph10 335 omitted from the compiled regex. However, this means that if the group
88     was called as a subroutine from elsewhere in the pattern, things went wrong
89 ph10 345 (an internal error was given). Such groups are now left in the compiled
90     pattern, with a new opcode that causes them to be skipped at execution
91 ph10 335 time.
92 ph10 345
93 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
94     to the way PCRE behaves:
95 ph10 345
96 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
97 ph10 345
98     (b) A back reference to an unmatched subpattern matches an empty string
99 ph10 336 (Perl fails the current match path).
100 ph10 345
101 ph10 341 (c) A data ] in a character class must be notated as \] because if the
102 ph10 345 first data character in a class is ], it defines an empty class. (In
103 ph10 341 Perl it is not possible to have an empty class.) The empty class []
104     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
105     The negative empty class [^] matches any one character, independently
106     of the DOTALL setting.
107 ph10 345
108     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
109 ph10 340 non-existent subpattern following a character class starting with ']' and
110     containing () gave an internal compiling error instead of "reference to
111     non-existent subpattern". Fortunately, when the pattern did exist, the
112 ph10 345 compiled code was correct. (When scanning forwards to check for the
113 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
114 ph10 345 the class, so got the count wrong. When actually compiling, the reference
115 ph10 340 was subsequently set up correctly.)
116 ph10 345
117 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
118 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
119     other assertions are supported. I have made pcre_dfa_exec() support
120     (*FAIL).
122 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
123 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
124     cannot be changed at match time, I realized I could make a small
125     improvement to matching performance by compiling OP_ALLANY instead of
126     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
127     on the OP_ANY path.
129     17. Compiling pcretest on Windows with readline support failed without the
130 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
131 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
133 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
134 ph10 345 ncurses library to be included for pcretest when ReadLine support is
135     requested, but also to allow for it to be overridden. This patch came from
136     Daniel Bergström.
137 ph10 347
138 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
139 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
140     any errors with the current Unicode tables. Thanks to Peter Kankowski for
141     spotting this.
142 ph10 324
143 ph10 332
144 ph10 319 Version 7.6 28-Jan-08
145 ph10 300 ---------------------
147 ph10 302 1. A character class containing a very large number of characters with
148     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
149     overflow.
150 ph10 309
151     2. Patch to cut out the "long long" test in pcrecpp_unittest when
152     HAVE_LONG_LONG is not defined.
154 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
155 ph10 304 bring them up to date and include new features. This patch includes:
156 ph10 309
157 ph10 304 - Fixed PH's badly added libz and libbz2 support.
158     - Fixed a problem with static linking.
159 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
160 ph10 304 - Fixed dftables problem and added an option.
161     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
163     - Added readline support for pcretest.
164 ph10 309 - Added an listing of the option settings after cmake has run.
166 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
167     "pcre.dll" under mingw when using Configure/Make. I added stuff to
168     Makefile.am that cause it to include this special target, without
169     affecting anything else. Note that the same mingw target plus all
170     the other distribution libraries and programs are now supported
171     when configuring with CMake (see 6 below) instead of with
172     Configure/Make.
173 ph10 309
174 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
175     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
176 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
177     solves the problem, but it does no harm.
178 ph10 313
179 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
180 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
181 ph10 314 with CMake, and also correct the comment about stack recursion.
182 ph10 313
183 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
184 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
185     of a program that users should build themselves after PCRE is installed, so
186     building it automatically is not really right. What is more, it gave
187 ph10 312 trouble in some build environments.
188 ph10 300
189 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
190 ph10 308
191 ph10 319
192 ph10 298 Version 7.5 10-Jan-08
193 ph10 263 ---------------------
195     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
196     values in parens when parsing an RE using the C++ wrapper."
197 ph10 286
198 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
199     Characters greater than 255 were excluded from the class instead of being
200     included.
201 ph10 286
202     3. The same bug as (2) above applied to negated POSIX classes such as
203 ph10 265 [:^space:].
204 ph10 286
205 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
206     defined or documented. It seems to have been a typo for PCRE_STATIC, so
207 ph10 286 I have changed it.
209 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
210 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
211     first named subpattern whose name started with "a" (in other words, the
212 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
213     expected" is now given for (?&) (a zero-length name), and this patch also
214     makes it give the same error for \k'' (previously it complained that that
215     was a reference to a non-existent subpattern).
216 ph10 286
217 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
218 ph10 286 this is right because (?- can be followed by option settings as well as by
219 ph10 269 digits. I have, however, made the messages clearer.
220 ph10 286
221 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
222     than the number used in the conditional) now cause a compile-time error.
223     This is actually not compatible with Perl, which accepts such patterns, but
224     treats the conditional as always being FALSE (as PCRE used to), but it
225     seems to me that giving a diagnostic is better.
226 ph10 286
227 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
228 ph10 275 and messages.
229 ph10 286
230     9. Fix two occurrences of "backslash" in comments that should have been
231     "backspace".
233     10. Remove two redundant lines of code that can never be obeyed (their function
234     was moved elsewhere).
236     11. The program that makes PCRE's Unicode character property table had a bug
237     which caused it to generate incorrect table entries for sequences of
238 ph10 277 characters that have the same character type, but are in different scripts.
239 ph10 286 It amalgamated them into a single range, with the script of the first of
240 ph10 277 them. In other words, some characters were in the wrong script. There were
241     thirteen such cases, affecting characters in the following ranges:
242 ph10 286
243 ph10 277 U+002b0 - U+002c1
244     U+0060c - U+0060d
245 ph10 286 U+0061e - U+00612
246 ph10 277 U+0064b - U+0065e
247     U+0074d - U+0076d
248     U+01800 - U+01805
249     U+01d00 - U+01d77
250     U+01d9b - U+01dbf
251     U+0200b - U+0200f
252     U+030fc - U+030fe
253     U+03260 - U+0327f
254     U+0fb46 - U+0fbb1
255     U+10450 - U+1049d
256 ph10 286
257 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
258     compatible with GNU grep in that, if there was more than one match in a
259     line, it showed only the first of them. It now behaves in the same way as
260     GNU grep.
261 ph10 286
262     13. If the -o and -v options were combined for pcregrep, it printed a blank
263     line for every non-matching line. GNU grep prints nothing, and pcregrep now
264     does the same. The return code can be used to tell if there were any
265     non-matching lines.
267 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
269     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
270 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
271 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
272     and both kinds of lookbehind were skipped).
274 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
275 ph10 284 inclusion of <windows.h> to before rather than after the definition of
276     INVALID_FILE_ATTRIBUTES (patch from David Byron).
277 ph10 263
278 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
279 ph10 286 character property caused pcre_compile() to compile bad code, which led at
280     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
281     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
282     caused the error; without that there was no problem.
283 ph10 263
284 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
285 ph10 286
286 ph10 289 19. Added --enable-pcretest-libreadline.
287 ph10 286
288 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
289 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
290 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
291     later patch that removed the other one (the right fix) and added unit tests
292     that check the return values (which was not done before).
293 ph10 292
294 ph10 291 21. Several CMake things:
295 ph10 287
296 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
297 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
298 ph10 288
299 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
300     linked with the newly-built libraries, not previously installed ones.
301 ph10 291
303 ph10 298
304     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
305     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
306     UTF-8 newline character). The key issue is that the pattern starts .*;
307     this means that the match must be either at the beginning, or after a
308     newline. The bug was in the code for advancing after a failed match and
309     checking that the new position followed a newline. It was not taking
310 ph10 294 account of UTF-8 characters correctly.
311 ph10 298
312     23. PCRE was behaving differently from Perl in the way it recognized POSIX
313     character classes. PCRE was not treating the sequence [:...:] as a
314     character class unless the ... were all letters. Perl, however, seems to
315     allow any characters between [: and :], though of course it rejects as
316     unknown any "names" that contain non-letters, because all the known class
317     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
318     for example, whereas PCRE did not - it did not recognize a POSIX character
319     class. This seemed a bit dangerous, so the code has been changed to be
320     closer to Perl. The behaviour is not identical to Perl, because PCRE will
321     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
322     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
323     Perl does, and where it didn't before.
325 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
326     Windows environments %n is disabled by default.
327 ph10 292
329 ph10 260 Version 7.4 21-Sep-07
330 ph10 230 ---------------------
332     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
333 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
334     LF". That isn't really right - the whole point of the change was to try to
335     help when there was an actual mention of one of the two characters. So now
336     the change happens only if \r or \n (or a literal CR or LF) character is
337 ph10 230 encountered.
338 ph10 231
339     2. The 32-bit options word was also used for 6 internal flags, but the numbers
340     of both had grown to the point where there were only 3 bits left.
341     Fortunately, there was spare space in the data structure, and so I have
342     moved the internal flags into a new 16-bit field to free up more option
343 ph10 230 bits.
344 ph10 231
345     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
346     but did not set the internal JCHANGED flag - either of these is enough to
347     control the way the "get" function works - but the PCRE_INFO_JCHANGED
348     facility is supposed to tell if (?J) was ever used, so now (?J) at the
349 ph10 230 start sets both bits.
351 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
352     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
353 ph10 230
354 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
356     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
357 ph10 233 compatibility, even though it is no longer used.
358 ph10 243
359     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
360 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
361 ph10 259 windows.h file is present (where different names are used). [This was
362 ph10 257 reversed later after testing - see 16 below.]
363 ph10 243
364     8. Changed all #include <config.h> to #include "config.h". There were also
365 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
366 ph10 243
367 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
368 ph10 243 sequence off the lines that it output.
370     10. It was pointed out to me that arrays of string pointers cause lots of
371     relocations when a shared library is dynamically loaded. A technique of
372     using a single long string with a table of offsets can drastically reduce
373     these. I have refactored PCRE in four places to do this. The result is
374 ph10 240 dramatic:
375 ph10 243
376 ph10 240 Originally: 290
377     After changing UCP table: 187
378 ph10 243 After changing error message table: 43
379 ph10 240 After changing table of "verbs" 36
380     After changing table of Posix names 22
381 ph10 243
382 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
383 ph10 247
384 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
385 ph10 247 unicode-properties was also set.
387 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
388 ph10 231
389 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
390     checked only for CRLF.
391 ph10 233
392 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
394 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
395 ph10 253
396 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
397 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
398     entirely. This removes changes made in 7 above.
399 ph10 256
400 ph10 261 17. The CMake files have been updated, and there is now more information about
401     building with CMake in the NON-UNIX-USE document.
402 ph10 257
403 ph10 261
404 ph10 228 Version 7.3 28-Aug-07
405 ph10 157 ---------------------
407 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
408     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
409     brackets there is not right, since it causes compilers to look for an
410     installed pcre.h, not the version that is in the source that is being
411     compiled (which of course may be different). I have changed it back to:
412 ph10 197
413 ph10 189 #include "pcre.h"
414 ph10 197
415     I have a vague recollection that the change was concerned with compiling in
416     different directories, but in the new build system, that is taken care of
417     by the VPATH setting the Makefile.
419 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
420     when the subject happened to end in the byte 0x85 (e.g. if the last
421     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
422     characters but of course it shouldn't be taken as a newline when it is part
423     of another character. The bug was that, for an unlimited repeat of . in
424     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
425     characters when looking for a newline.
426 ph10 197
427     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
429     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
430     in debug output.
432 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
433     long printing in the pcrecpp unittest when running under MinGW.
434 ph10 189
435 ph10 197 6. ESC_K was left out of the EBCDIC table.
436 ph10 189
437 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
438     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
439     limit also applies to "virtual nesting" when a pattern is recursive, and in
440     this case 1000 isn't so big. I have been able to remove this limit at the
441     expense of backing off one optimization in certain circumstances. Normally,
442     when pcre_exec() would call its internal match() function recursively and
443     immediately return the result unconditionally, it uses a "tail recursion"
444     feature to save stack. However, when a subpattern that can match an empty
445     string has an unlimited repetition quantifier, it no longer makes this
446     optimization. That gives it a stack frame in which to save the data for
447     checking that an empty string has been matched. Previously this was taken
448     from the 1000-entry workspace that had been reserved. So now there is no
449     explicit limit, but more stack is used.
450 ph10 189
451 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
452     syntax that is required for Windows, and which was going wrong for the
453     pcreposix and pcrecpp parts of the library. These were overlooked when this
454     problem was solved for the main library.
455 ph10 197
456 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
457     the size of patterns that contain repeated groups with explicit upper
458     limits. As the maximum quantifier is 65535, the maximum group length was
459     set at 30,000 so that the product of these two numbers did not overflow a
460     32-bit integer. However, it turns out that people want to use groups that
461     are longer than 30,000 bytes (though not repeat them that many times).
462     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
463     made it possible to implement the integer overflow checks in a much more
464     dynamic way, which I have now done. The artificial limitation on group
465     length has been removed - we now have only the limit on the total length of
466     the compiled pattern, which depends on the LINK_SIZE setting.
467 ph10 208
468     10. Fixed a bug in the documentation for get/copy named substring when
469     duplicate names are permitted. If none of the named substrings are set, the
470     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
471     empty string.
473     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
474     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
475     because the ] is interpreted as the first data character and the
476     terminating ] is not found. PCRE has been made compatible with Perl in this
477     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
478     cause memory overwriting.
480 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
481     string has been matched (to stop an infinite loop). It was not recognizing
482 ph10 208 a conditional subpattern that could match an empty string if that
483 ph10 206 subpattern was within another subpattern. For example, it looped when
484 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
485 ph10 206 condition was not nested. This bug has been fixed.
486 ph10 208
487 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
488     past the start of the subject in the presence of bytes with the top bit
489     set, for example "\x8aBCD".
490 ph10 211
491 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
492     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
493 ph10 200
494 ph10 211 14. Optimized (?!) to (*FAIL).
495 ph10 202
496 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
497     This restricts code points to be within the range 0 to 0x10FFFF, excluding
498     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
499     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
500     does: it's just the validity check that is more restrictive.
501 ph10 220
502     16. Inserted checks for integer overflows during escape sequence (backslash)
503     processing, and also fixed erroneous offset values for syntax errors during
504     backslash processing.
506 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
507 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
509 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
510     caused an overrun.
511 ph10 220
512     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
513     something other than just ASCII characters) inside a group that had an
514     unlimited repeat caused a loop at compile time (while checking to see
515     whether the group could match an empty string).
517 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
518     [\P{Any}] did so. (Error in the code for printing property names.)
519 ph10 210
520 ph10 220 21. An orphan \E inside a character class could cause a crash.
522     22. A repeated capturing bracket such as (A)? could cause a wild memory
523 ph10 218 reference during compilation.
524 ph10 220
525     23. There are several functions in pcre_compile() that scan along a compiled
526     expression for various reasons (e.g. to see if it's fixed length for look
527 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
528 ph10 220 present in the pattern. These operators have additional parameters compared
529     with \d, etc, and these were not being taken into account when moving along
530 ph10 218 the compiled data. Specifically:
531 ph10 220
532     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
533     length.
535     (b) An item such as \pL+ within a repeated group could cause crashes or
536 ph10 218 loops.
537 ph10 220
538 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
539 ph10 220 "reference to non-existent subpattern" error.
541 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
543 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
544 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
545 ph10 211
546 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
547 ph10 218
548 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
549 ph10 223 character were causing crashes (broken optimization).
550 ph10 227
551 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
552 ph10 227 \p or \P) caused a compile-time loop.
554 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
555     break. For example, the unstudied pattern [\r\n]A does not match the string
556     "\r\nA" because change 7.0/46 below moves the current point on by two
557     characters after failing to match at the start. However, the pattern \nA
558 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
559     the same is true. There doesn't seem any very clean way out of this, but
560     what I have chosen to do makes the common cases work: PCRE now takes note
561     of whether there can be an explicit match for \r or \n anywhere in the
562     pattern, and if so, 7.0/46 no longer applies. As part of this change,
563     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
564     pattern has explicit CR or LF references.
565 ph10 222
566 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
567 ph10 223
568 ph10 227
569 ph10 189 Version 7.2 19-Jun-07
570     ---------------------
572 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
573     which is apparently normally available under Windows.
574 ph10 159
575     2. Re-jig the pcregrep tests with different newline settings in an attempt
576     to make them independent of the local environment's newline setting.
577 ph10 157
578 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
579 ph10 165
580 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
581     was not 2, because the output contained actual offsets. The recent new
582 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
583     usable with all link sizes.
585 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
586     stack recursion. This gives a massive performance boost under BSD, but just
587 ph10 165 a small improvement under Linux. However, it saves one field in the frame
588 ph10 164 in all cases.
589 ph10 172
590 ph10 166 6. Added more features from the forthcoming Perl 5.10:
591 ph10 172
592 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
593     recursion call. It refers to the nth most recently opened parentheses.
594 ph10 172
595 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
596 ph10 172 to be opened parentheses.
598     (c) Conditions that refer to capturing parentheses can be specified
599 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
600 ph10 172
601 ph10 168 (d) \K resets the start of the current match so that everything before
602 ph10 172 is not part of it.
604 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
605 ph10 172
606 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
607 ph10 172 reference syntax.
608 ph10 182
609 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
610 ph10 182 alternative starts with the same number.
611 ph10 172
612 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
614 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
617     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
618     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
619 ph10 170 for detecting groups that can match an empty string.
620 ph10 159
621 ph10 172 9. A pattern with a very large number of alternatives (more than several
622     hundred) was running out of internal workspace during the pre-compile
623     phase, where pcre_compile() figures out how much memory will be needed. A
624     bit of new cunning has reduced the workspace needed for groups with
625     alternatives. The 1000-alternative test pattern now uses 12 bytes of
626     workspace instead of running out of the 4096 that are available.
627 ph10 182
628 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
629 ph10 172
630 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
631     The report of the bug said:
632 ph10 182
633 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
634     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
635 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
636 ph10 185
637 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
638 ph10 185 it matched the wrong number of bytes.
639 ph10 172
640 ph10 179
641 ph10 155 Version 7.1 24-Apr-07
642 ph10 98 ---------------------
644 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
645 ph10 122 that is more "standard", making use of automake and other Autotools. There
646 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
647     on this.
648 ph10 111
649     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
650     for recursive directory scanning broke on some systems because the files
651     are not scanned in any specific order and on different systems the order
652     was different. A call to "sort" has been inserted into RunGrepTest for the
653     approprate test as a short-term fix. In the longer term there may be an
654 ph10 100 alternative.
655 ph10 111
656 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
657 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
658     people do their own conversions for various reasons). The problems
659     concerned the use of low-level troff macros .br and .in. I have therefore
660     removed all such uses from the man pages (some were redundant, some could
661 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
662     HTML has been updated to handle .nf/.fi and to complain if it encounters
663     .br or .in.
664 ph10 111
665 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
666 ph10 123 arranged for config.h to be included in the distribution, with the name
667 ph10 111 config.h.generic, for the benefit of those who have to compile without
668     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
670     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
671     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
672 ph10 127 makevp.bat for the current PCRE, using the additional files
673 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
674 ph10 111
675     6. A Windows user reported a minor discrepancy with test 2, which turned out
676     to be caused by a trailing space on an input line that had got lost in his
677 ph10 102 copy. The trailing space was an accident, so I've just removed it.
678 ph10 111
679 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
680 ph10 111 that is needed.
682 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
683     as "const" (a) because they are and (b) because it helps the PHP
684     maintainers who have recently made a script to detect big data structures
685 ph10 111 in the php code that should be moved to the .rodata section. I remembered
686     to update Builducptable as well, so it won't revert if ucptable.h is ever
687 ph10 105 re-created.
688 ph10 111
689     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
690 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
691 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
692     support is not required. This saves 1.5-2K of code, which is important in
693 ph10 107 some applications.
694 ph10 111
695 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
696 ph10 111 so as not to refer to the tables, even though these functions will never be
697     called when UTF-8 support is disabled. Otherwise there are problems with a
698     shared library.
700 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
702     (a) It was defining its arguments as char * instead of void *.
704 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
705     a long time ago when I wrote it, but is no longer the case.
707 ph10 118 The emulated memove() is provided for those environments that have neither
708 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
709 ph10 118 is clearly not the case, as these two bugs were recently reported.
710 ph10 123
711 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
712 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
713     pages, and it removes trailing spaces from listed files. It also creates
714     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
715     case, it wraps all the #defines with #ifndefs. This script should be run
716 ph10 111 before "make dist".
717 ph10 123
718 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
719     with Unicode property support.
720 ph10 123
721     (a) For a maximizing quantifier, if the two different cases of the
722     character were of different lengths in their UTF-8 codings (there are
723     some cases like this - I found 11), and the matching function had to
724 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
725     were both the same length.
726 ph10 123
727     (b) When PCRE was configured to use the heap rather than the stack for
728     recursion during matching, it was not correctly preserving the data for
729     the other case of a UTF-8 character when checking ahead for a match
730     while processing a minimizing repeat. If the check also involved
731 ph10 115 matching a wide character, but failed, corruption could cause an
732     erroneous result when trying to check for a repeat of the original
733     character.
734 ph10 123
735 ph10 116 13. Some tidying changes to the testing mechanism:
736 ph10 98
737 ph10 116 (a) The RunTest script now detects the internal link size and whether there
738     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
739 ph10 123 values substituted by "configure". (The RunGrepTest script already did
740     this for UTF-8.) The configure.ac script no longer substitutes the
741     relevant variables.
743 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
744     with length and offset values. This means that the output is different
745     for different internal link sizes. Test 2 is skipped for link sizes
746     other than 2 because of this, bypassing the problem. Unfortunately,
747     there was also a test in test 3 (the locale tests) that used /B and
748 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
749     I have added a new /Z option to pcretest that replaces the length and
750     offset values with spaces. This is now used to make test 3 independent
751 ph10 122 of link size. (Test 2 will be tidied up later.)
752 ph10 123
753     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
754 ph10 122 segmentation fault instead of returning the appropriate error message.
755 ph10 134
756 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
757 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
758     This doesn't seem right; it now treats the CRLF combination as the line
759     ending, and so does not match in that case. It's only a pattern such as ^$
760     that would hit this one: something like ^ABC$ would have failed after \r
761     and then tried again after \r\n.
763 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
764 ph10 134 in an attempt to make files that differ only in their line terminators
765     compare equal. This works on Linux.
766 ph10 142
767 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
768     as it exited. This is now fixed, thanks to valgrind.
769 ph10 142
770 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
771 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
772     was because its rules for how to advance for /g after matching an empty
773 ph10 143 string at the end of a line did not allow for this case. They now check for
774     it specially.
775 ph10 150
776     20. pcretest is supposed to handle patterns and data of any length, by
777     extending its buffers when necessary. It was getting this wrong when the
778 ph10 147 buffer for a data line had to be extended.
779 ph10 150
780 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
781 ph10 150 CRLF as a newline sequence.
782 ph10 152
783 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
784 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
785     I have nevertheless tidied it up.
786 ph10 111
787 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
788 ph10 123
789 ph10 153 24. Added a man page for pcre-config.
790 ph10 152
791 ph10 153
792 nigel 93 Version 7.0 19-Dec-06
793     ---------------------
795     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
796     moving to gcc 4.1.1.
798     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
799     sys/time.h, which is documented as needed for this function. It doesn't
800     seem to matter on Linux, but it showed up on some releases of OS X.
802     3. It seems that there are systems where bytes whose values are greater than
803     127 match isprint() in the "C" locale. The "C" locale should be the
804     default when a C program starts up. In most systems, only ASCII printing
805     characters match isprint(). This difference caused the output from pcretest
806     to vary, making some of the tests fail. I have changed pcretest so that:
808     (a) When it is outputting text in the compiled version of a pattern, bytes
809     other than 32-126 are always shown as hex escapes.
811     (b) When it is outputting text that is a matched part of a subject string,
812     it does the same, unless a different locale has been set for the match
813     (using the /L modifier). In this case, it uses isprint() to decide.
815     4. Fixed a major bug that caused incorrect computation of the amount of memory
816     required for a compiled pattern when options that changed within the
817     pattern affected the logic of the preliminary scan that determines the
818     length. The relevant options are -x, and -i in UTF-8 mode. The result was
819     that the computed length was too small. The symptoms of this bug were
820     either the PCRE error "internal error: code overflow" from pcre_compile(),
821     or a glibc crash with a message such as "pcretest: free(): invalid next
822     size (fast)". Examples of patterns that provoked this bug (shown in
823     pcretest format) are:
825     /(?-x: )/x
826     /(?x)(?-x: \s*#\s*)/
827     /((?i)[\x{c0}])/8
828     /(?i:[\x{c0}])/8
830     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
831     is now done differently.
833     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
834     wrapper classes; (b) implement a new function in the C++ scanner that is
835     more efficient than the old way of doing things because it avoids levels of
836     recursion in the regex matching; (c) add a paragraph to the documentation
837     for the FullMatch() function.
839     6. The escape sequence \n was being treated as whatever was defined as
840     "newline". Not only was this contrary to the documentation, which states
841     that \n is character 10 (hex 0A), but it also went horribly wrong when
842     "newline" was defined as CRLF. This has been fixed.
844     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
845     was being set to -1 for the "end of line" case (supposedly a value that no
846     character can have). Though this value is never used (the check for end of
847     line is "zero bytes in current character"), it caused compiler complaints.
848     I've changed it to 0xffffffff.
850     8. In pcre_version.c, the version string was being built by a sequence of
851     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
852     string (as it is for production releases) called a macro with an empty
853     argument. The C standard says the result of this is undefined. The gcc
854     compiler treats it as an empty string (which was what was wanted) but it is
855     reported that Visual C gives an error. The source has been hacked around to
856     avoid this problem.
858     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
859     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
860     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
861     of them did).
863     10. Originally, pcretest opened its input and output without "b"; then I was
864     told that "b" was needed in some environments, so it was added for release
865     5.0 to both the input and output. (It makes no difference on Unix-like
866     systems.) Later I was told that it is wrong for the input on Windows. I've
867     now abstracted the modes into two macros, to make it easier to fiddle with
868     them, and removed "b" from the input mode under Windows.
870     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
872     12. Added -help and --help to pcretest as an official way of being reminded
873     of the options.
875     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
876     and pcrecpp.cc because they annoy compilers at high warning levels.
878     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
880     15. Fixed an occurrence of == in configure.ac that should have been = (shell
881     scripts are not C programs :-) and which was not noticed because it works
882     on Linux.
884     16. pcretest is supposed to handle any length of pattern and data line (as one
885     line or as a continued sequence of lines) by extending its input buffer if
886     necessary. This feature was broken for very long pattern lines, leading to
887     a string of junk being passed to pcre_compile() if the pattern was longer
888     than about 50K.
890     17. I have done a major re-factoring of the way pcre_compile() computes the
891     amount of memory needed for a compiled pattern. Previously, there was code
892     that made a preliminary scan of the pattern in order to do this. That was
893     OK when PCRE was new, but as the facilities have expanded, it has become
894     harder and harder to keep it in step with the real compile phase, and there
895     have been a number of bugs (see for example, 4 above). I have now found a
896     cunning way of running the real compile function in a "fake" mode that
897     enables it to compute how much memory it would need, while actually only
898     ever using a few hundred bytes of working memory and without too many
899     tests of the mode. This should make future maintenance and development
900     easier. A side effect of this work is that the limit of 200 on the nesting
901     depth of parentheses has been removed (though this was never a serious
902     limitation, I suspect). However, there is a downside: pcre_compile() now
903     runs more slowly than before (30% or more, depending on the pattern). I
904     hope this isn't a big issue. There is no effect on runtime performance.
906     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
907     newline (only possible for the last line of a file) and it was a
908     pattern that set a locale (followed by /Lsomething), pcretest crashed.
910     19. Added additional timing features to pcretest. (1) The -tm option now times
911     matching only, not compiling. (2) Both -t and -tm can be followed, as a
912     separate command line item, by a number that specifies the number of
913     repeats to use when timing. The default is 50000; this gives better
914     precision, but takes uncomfortably long for very large patterns.
916     20. Extended pcre_study() to be more clever in cases where a branch of a
917     subpattern has no definite first character. For example, (a*|b*)[cd] would
918     previously give no result from pcre_study(). Now it recognizes that the
919     first character must be a, b, c, or d.
921     21. There was an incorrect error "recursive call could loop indefinitely" if
922     a subpattern (or the entire pattern) that was being tested for matching an
923     empty string contained only one non-empty item after a nested subpattern.
924     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
925     incorrectly, because the \d was being skipped in the check.
927     22. The pcretest program now has a new pattern option /B and a command line
928     option -b, which is equivalent to adding /B to every pattern. This causes
929     it to show the compiled bytecode, without the additional information that
930     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
931     is the same as /B/I).
933     23. A new optimization is now able automatically to treat some sequences such
934     as a*b as a*+b. More specifically, if something simple (such as a character
935     or a simple class like \d) has an unlimited quantifier, and is followed by
936     something that cannot possibly match the quantified thing, the quantifier
937     is automatically "possessified".
939     24. A recursive reference to a subpattern whose number was greater than 39
940     went wrong under certain circumstances in UTF-8 mode. This bug could also
941     have affected the operation of pcre_study().
943     25. Realized that a little bit of performance could be had by replacing
944     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
946     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
948     27. Possessive quantifiers such as a++ were previously implemented by turning
949     them into atomic groups such as ($>a+). Now they have their own opcodes,
950     which improves performance. This includes the automatically created ones
951     from 23 above.
953     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
954     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
955     the first matched character to be a colon. This applied both to named and
956     numbered groups.
958     29. The ucpinternal.h header file was missing its idempotency #ifdef.
960     30. I was sent a "project" file called libpcre.a.dev which I understand makes
961     building PCRE on Windows easier, so I have included it in the distribution.
963     31. There is now a check in pcretest against a ridiculously large number being
964     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
965     loop, the loop is abandoned.
967     32. Forward references to subpatterns in conditions such as (?(2)...) where
968     subpattern 2 is defined later cause pcre_compile() to search forwards in
969     the pattern for the relevant set of parentheses. This search went wrong
970     when there were unescaped parentheses in a character class, parentheses
971     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
973     33. "Subroutine" calls and backreferences were previously restricted to
974     referencing subpatterns earlier in the regex. This restriction has now
975     been removed.
977     34. Added a number of extra features that are going to be in Perl 5.10. On the
978     whole, these are just syntactic alternatives for features that PCRE had
979     previously implemented using the Python syntax or my own invention. The
980     other formats are all retained for compatibility.
982     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
983     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
984     also .NET compatible.
986     (b) A recursion or subroutine call to a named group can now be defined as
987     (?&name) as well as (?P>name).
989     (c) A backreference to a named group can now be defined as \k<name> or
990     \k'name' as well as (?P=name). The new forms, as well as being in Perl
991     5.10, are also .NET compatible.
993     (d) A conditional reference to a named group can now use the syntax
994     (?(<name>) or (?('name') as well as (?(name).
996     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
997     groups (named and numbered) that are never evaluated inline, but can be
998     called as "subroutines" from elsewhere. In effect, the DEFINE condition
999     is always false. There may be only one alternative in such a group.
1001     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1002     as the simple (?(R). The condition is true only if the most recent
1003     recursion is that of the given number or name. It does not search out
1004     through the entire recursion stack.
1006     (g) The escape \gN or \g{N} has been added, where N is a positive or
1007     negative number, specifying an absolute or relative reference.
1009     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1010     some "unreachable code" warnings.
1012     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1013     things, this adds five new scripts.
1015     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1016     There were also incompatibilities regarding the handling of \Q..\E inside
1017     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1018     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1020     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1021     matches an empty string, and forcibly breaks the loop. There were bugs in
1022     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1023     against aaaa the result was just "a" rather than "aaaa", for example. Two
1024     separate and independent bugs (that affected different cases) have been
1025     fixed.
1027     39. Refactored the code to abolish the use of different opcodes for small
1028     capturing bracket numbers. This is a tidy that I avoided doing when I
1029     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1030     The new approach is not only tidier, it makes it possible to reduce the
1031     memory needed to fix the previous bug (38).
1033     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1034     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1035     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1036     mode.
1038     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1039     report.
1041     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1042     copy construction and assignment in the C++ wrapper.
1044     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1045     couple of bugs that could have given wrong results in the "--newline=crlf"
1046     case.
1048     44. Added a number of casts and did some reorganization of signed/unsigned int
1049     variables following suggestions from Dair Grant. Also renamed the variable
1050     "this" as "item" because it is a C++ keyword.
1052     45. Arranged for dftables to add
1054     #include "pcre_internal.h"
1056     to pcre_chartables.c because without it, gcc 4.x may remove the array
1057     definition from the final binary if PCRE is built into a static library and
1058     dead code stripping is activated.
1060     46. For an unanchored pattern, if a match attempt fails at the start of a
1061     newline sequence, and the newline setting is CRLF or ANY, and the next two
1062     characters are CRLF, advance by two characters instead of one.
1065 nigel 91 Version 6.7 04-Jul-06
1066     ---------------------
1068     1. In order to handle tests when input lines are enormously long, pcretest has
1069     been re-factored so that it automatically extends its buffers when
1070     necessary. The code is crude, but this _is_ just a test program. The
1071     default size has been increased from 32K to 50K.
1073     2. The code in pcre_study() was using the value of the re argument before
1074     testing it for NULL. (Of course, in any sensible call of the function, it
1075     won't be NULL.)
1077     3. The memmove() emulation function in pcre_internal.h, which is used on
1078     systems that lack both memmove() and bcopy() - that is, hardly ever -
1079     was missing a "static" storage class specifier.
1081     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1082     containing an extended class (one that cannot be represented by a bitmap
1083     because it contains high-valued characters or Unicode property items, e.g.
1084     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1085     pattern, but PCRE should not loop if you do not (it no longer does).
1086     [Detail: two cases were found: (a) a repeated subpattern containing an
1087     extended class; (b) a recursive reference to a subpattern that followed a
1088     previous extended class. It wasn't skipping over the extended class
1089     correctly when UTF-8 mode was not set.]
1091     5. A negated single-character class was not being recognized as fixed-length
1092     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1093     compile error "lookbehind assertion is not fixed length".
1095     6. The RunPerlTest auxiliary script was showing an unexpected difference
1096     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1097     write a Perl script that can interpret lines of an input file either as
1098     byte characters or as UTF-8, which is what "perltest" was being required to
1099     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1100     can't do is switch easily at run time between having the "use utf8;" pragma
1101     or not. In the end, I fudged it by using the RunPerlTest script to insert
1102     "use utf8;" explicitly for the UTF-8 tests.
1104     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1105     the end of the subject string, contrary to the documentation and to what
1106     Perl does. This was true of both matching functions. Now it matches only at
1107     the start of the subject and immediately after *internal* newlines.
1109     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1110     a pointer to an int instead of a pointer to an unsigned long int. This
1111     caused problems on 64-bit systems.
1113     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1114     instance of the 'standard' template library not being so standard".
1116     10. There was no check on the number of named subpatterns nor the maximum
1117     length of a subpattern name. The product of these values is used to compute
1118     the size of the memory block for a compiled pattern. By supplying a very
1119     long subpattern name and a large number of named subpatterns, the size
1120     computation could be caused to overflow. This is now prevented by limiting
1121     the length of names to 32 characters, and the number of named subpatterns
1122     to 10,000.
1124     11. Subpatterns that are repeated with specific counts have to be replicated in
1125     the compiled pattern. The size of memory for this was computed from the
1126     length of the subpattern and the repeat count. The latter is limited to
1127     65535, but there was no limit on the former, meaning that integer overflow
1128     could in principle occur. The compiled length of a repeated subpattern is
1129     now limited to 30,000 bytes in order to prevent this.
1131     12. Added the optional facility to have named substrings with the same name.
1133     13. Added the ability to use a named substring as a condition, using the
1134     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1135     are numbers (not recommended). Forward references are permitted.
1137     14. Added forward references in named backreferences (if you see what I mean).
1139     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1140     pattern could run off the end of the subject. For example, the pattern
1141     "(?s)(.{1,5})"8 did this with the subject "ab".
1143     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1144     PCRE_CASELESS was set when matching characters that were quantified with ?
1145     or *.
1147     17. A character class other than a single negated character that had a minimum
1148     but no maximum quantifier - for example [ab]{6,} - was not handled
1149     correctly by pce_dfa_exec(). It would match only one character.
1151     18. A valid (though odd) pattern that looked like a POSIX character
1152     class but used an invalid character after [ (for example [[,abc,]]) caused
1153     pcre_compile() to give the error "Failed: internal error: code overflow" or
1154     in some cases to crash with a glibc free() error. This could even happen if
1155     the pattern terminated after [[ but there just happened to be a sequence of
1156     letters, a binary zero, and a closing ] in the memory that followed.
1158     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1159     over the years. Originally (before any Unicode support), just the bottom 8
1160     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1161     output from "man perlunicode" includes this:
1163     The regular expression compiler produces polymorphic opcodes. That
1164     is, the pattern adapts to the data and automatically switches to
1165     the Unicode character scheme when presented with Unicode data--or
1166     instead uses a traditional byte scheme when presented with byte
1167     data.
1169     Sadly, a wide octal escape does not cause a switch, and in a string with
1170     no other multibyte characters, these octal escapes are treated as before.
1171     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1172     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1173     Unicode string.
1175     I have not perpetrated such confusion in PCRE. Up till now, it took just
1176     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1177     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1178     translate to the appropriate multibyte character.
1180     29. Applied some refactoring to reduce the number of warnings from Microsoft
1181     and Borland compilers. This has included removing the fudge introduced
1182     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1183     a warning about an unused variable.
1185     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1186     characters since release 4.0, because Perl (from release 5.004) does not.
1187     [Or at least, is documented not to: some releases seem to be in conflict
1188     with the documentation.] However, when a pattern was studied with
1189     pcre_study() and all its branches started with \s, PCRE still included VT
1190     as a possible starting character. Of course, this did no harm; it just
1191     caused an unnecessary match attempt.
1193     22. Removed a now-redundant internal flag bit that recorded the fact that case
1194     dependency changed within the pattern. This was once needed for "required
1195     byte" processing, but is no longer used. This recovers a now-scarce options
1196     bit. Also moved the least significant internal flag bit to the most-
1197     significant bit of the word, which was not previously used (hangover from
1198     the days when it was an int rather than a uint) to free up another bit for
1199     the future.
1201     23. Added support for CRLF line endings as well as CR and LF. As well as the
1202     default being selectable at build time, it can now be changed at runtime
1203     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1204     specify that it is scanning data with non-default line endings.
1206     24. Changed the definition of CXXLINK to make it agree with the definition of
1207     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1209     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1210     recursions. This makes a big different to stack usage for some patterns.
1212     26. If a subpattern containing a named recursion or subroutine reference such
1213     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1214     the space required for the compiled pattern went wrong and gave too small a
1215     value. Depending on the environment, this could lead to "Failed: internal
1216     error: code overflow at offset 49" or "glibc detected double free or
1217     corruption" errors.
1219     27. Applied patches from Google (a) to support the new newline modes and (b) to
1220     advance over multibyte UTF-8 characters in GlobalReplace.
1222     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1223     difference for some implementation of PCRE in some Windows version.
1225     29. Added some extra testing facilities to pcretest:
1227     \q<number> in a data line sets the "match limit" value
1228     \Q<number> in a data line sets the "match recursion limt" value
1229     -S <number> sets the stack size, where <number> is in megabytes
1231     The -S option isn't available for Windows.
1234 nigel 89 Version 6.6 06-Feb-06
1235     ---------------------
1237     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1238     in pcreposix.h. I have copied the definition from pcre.h.
1240     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1241     because pcre.h is no longer a built file.
1243     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1244     not normally included in the compiled code.
1247 nigel 87 Version 6.5 01-Feb-06
1248     ---------------------
1250     1. When using the partial match feature with pcre_dfa_exec(), it was not
1251     anchoring the second and subsequent partial matches at the new starting
1252     point. This could lead to incorrect results. For example, with the pattern
1253     /1234/, partially matching against "123" and then "a4" gave a match.
1255     2. Changes to pcregrep:
1257     (a) All non-match returns from pcre_exec() were being treated as failures
1258     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1259     error message is output. Some extra information is given for the
1261     probably the only errors that are likely to be caused by users (by
1262     specifying a regex that has nested indefinite repeats, for instance).
1263     If there are more than 20 of these errors, pcregrep is abandoned.
1265     (b) A binary zero was treated as data while matching, but terminated the
1266     output line if it was written out. This has been fixed: binary zeroes
1267     are now no different to any other data bytes.
1269     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1270     used to set a locale for matching. The --locale=xxxx long option has
1271     been added (no short equivalent) to specify a locale explicitly on the
1272     pcregrep command, overriding the environment variables.
1274     (d) When -B was used with -n, some line numbers in the output were one less
1275     than they should have been.
1277     (e) Added the -o (--only-matching) option.
1279     (f) If -A or -C was used with -c (count only), some lines of context were
1280     accidentally printed for the final match.
1282     (g) Added the -H (--with-filename) option.
1284     (h) The combination of options -rh failed to suppress file names for files
1285     that were found from directory arguments.
1287     (i) Added the -D (--devices) and -d (--directories) options.
1289     (j) Added the -F (--fixed-strings) option.
1291     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1293     (l) Added the --colo(u)r option.
1295     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1296     is not present by default.
1298     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1299     items such as (?R) or (?1), when the recursion could match a number of
1300     alternatives. If it matched one of the alternatives, but subsequently,
1301     outside the recursion, there was a failure, the code tried to back up into
1302     the recursion. However, because of the way PCRE is implemented, this is not
1303     possible, and the result was an incorrect result from the match.
1305     In order to prevent this happening, the specification of recursion has
1306     been changed so that all such subpatterns are automatically treated as
1307     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1309     4. I had overlooked the fact that, in some locales, there are characters for
1310     which isalpha() is true but neither isupper() nor islower() are true. In
1311     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1312     and ordfeminine) are like this. This affected the treatment of \w and \W
1313     when they appeared in character classes, but not when they appeared outside
1314     a character class. The bit map for "word" characters is now created
1315     separately from the results of isalnum() instead of just taking it from the
1316     upper, lower, and digit maps. (Plus the underscore character, of course.)
1318     5. The above bug also affected the handling of POSIX character classes such as
1319     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1320     permanent tables. Instead, the bit maps for such a class were previously
1321     created as the appropriate unions of the upper, lower, and digit bitmaps.
1322     Now they are created by subtraction from the [[:word:]] class, which has
1323     its own bitmap.
1325     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1326     It is created by subtracting the vertical space characters (\x09, \x0a,
1327     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1328     subtraction was done in the overall bitmap for a character class, meaning
1329     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1330     be recognized. This bug has been fixed.
1332     7. Patches from the folks at Google:
1334     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1335     real life, but is still worth protecting against".
1337     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1338     regular expressions".
1340     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1341     have it.
1343     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1344     "configure" and the latter not, in order to fix a problem somebody had
1345     with compiling the Arg class on HP-UX.
1347     (e) Improve the error-handling of the C++ wrapper a little bit.
1349     (f) New tests for checking recursion limiting.
1351     8. The pcre_memmove() function, which is used only if the environment does not
1352     have a standard memmove() function (and is therefore rarely compiled),
1353     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1354     returning a result (though PCRE never actually uses the result).
1356     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1357     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1358     returned instead of calling malloc() with an overflowing number that would
1359     most likely cause subsequent chaos.
1361     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1363     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1364     with this option is matched, the nmatch and pmatch options of regexec() are
1365     ignored.
1367     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1368     provided in case anyone wants to the the POSIX interface with UTF-8
1369     strings.
1371     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1372     C++ linking (needed for some HP-UX environments).
1374     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1375     (unused parameter) and in the pcre_printint() function (omitted "default"
1376     switch label when the default is to do nothing).
1378     15. Added some code to make it possible, when PCRE is compiled as a C++
1379     library, to replace subject pointers for pcre_exec() with a smart pointer
1380     class, thus making it possible to process discontinuous strings.
1382     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1383     much the same function. They were added by different people who were trying
1384     to make PCRE easy to compile on non-Unix systems. It has been suggested
1385     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1386     for compiling on Windows systems. I have therefore replaced it with
1387     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1388     defaults to "extern" for C or "extern C" for C++, which works fine on
1389     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1390     SCOPE with something explicit in config.h. In addition:
1392     (a) pcreposix.h still had just "extern" instead of either of these macros;
1393     I have replaced it with PCRE_DATA_SCOPE.
1395     (b) Functions such as _pcre_xclass(), which are internal to the library,
1396     but external in the C sense, all had PCRE_EXPORT in their definitions.
1397     This is apparently wrong for the Windows case, so I have removed it.
1398     (It makes no difference on Unix-like systems.)
1400     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1401     of recursive calls to match(). This is different to MATCH_LIMIT because
1402     that limits the total number of calls to match(), not all of which increase
1403     the depth of recursion. Limiting the recursion depth limits the amount of
1404     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1405     when PCRE is compiled, and changed at run time. A patch from Google adds
1406     this functionality to the C++ interface.
1408     18. Changes to the handling of Unicode character properties:
1410     (a) Updated the table to Unicode 4.1.0.
1412     (b) Recognize characters that are not in the table as "Cn" (undefined).
1414     (c) I revised the way the table is implemented to a much improved format
1415     which includes recognition of ranges. It now supports the ranges that
1416     are defined in UnicodeData.txt, and it also amalgamates other
1417     characters into ranges. This has reduced the number of entries in the
1418     table from around 16,000 to around 3,000, thus reducing its size
1419     considerably. I realized I did not need to use a tree structure after
1420     all - a binary chop search is just as efficient. Having reduced the
1421     number of entries, I extended their size from 6 bytes to 8 bytes to
1422     allow for more data.
1424     (d) Added support for Unicode script names via properties such as \p{Han}.
1426     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1427     matching that character.
1429     20. When matching a repeated Unicode property with a minimum greater than zero,
1430     (for example \pL{2,}), PCRE could look past the end of the subject if it
1431     reached it while seeking the minimum number of characters. This could
1432     happen only if some of the characters were more than one byte long, because
1433     there is a check for at least the minimum number of bytes.
1435     21. Refactored the implementation of \p and \P so as to be more general, to
1436     allow for more different types of property in future. This has changed the
1437     compiled form incompatibly. Anybody with saved compiled patterns that use
1438     \p or \P will have to recompile them.
1440     22. Added "Any" and "L&" to the supported property types.
1442     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1443     but give a compile time error if the value is greater than 0xff.
1445     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1446     accidentally not being installed or uninstalled.
1448     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1449     made were to insert the current release number. This seemed silly, because
1450     it made things harder for people building PCRE on systems that don't run
1451     "configure". I have turned pcre.h into a distributed file, no longer built
1452     by "configure", with the version identification directly included. There is
1453     no longer a pcre.h.in file.
1455     However, this change necessitated a change to the pcre-config script as
1456     well. It is built from pcre-config.in, and one of the substitutions was the
1457     release number. I have updated configure.ac so that ./configure now finds
1458     the release number by grepping pcre.h.
1460     26. Added the ability to run the tests under valgrind.
1463 nigel 85 Version 6.4 05-Sep-05
1464     ---------------------
1466     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1467     "--" to be printed when multiple files were scanned, even when none of the
1468     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1469     consider it to be a bug, and have restored the previous behaviour.
1471     2. A couple of code tidies to get rid of compiler warnings.
1473     3. The pcretest program used to cheat by referring to symbols in the library
1474     whose names begin with _pcre_. These are internal symbols that are not
1475     really supposed to be visible externally, and in some environments it is
1476     possible to suppress them. The cheating is now confined to including
1477     certain files from the library's source, which is a bit cleaner.
1479     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1480     file's purpose clearer.
1482     5. Reorganized pcre_ucp_findchar().
1485 nigel 83 Version 6.3 15-Aug-05
1486     ---------------------
1488     1. The file libpcre.pc.in did not have general read permission in the tarball.
1490     2. There were some problems when building without C++ support:
1492     (a) If C++ support was not built, "make install" and "make test" still
1493     tried to test it.
1495     (b) There were problems when the value of CXX was explicitly set. Some
1496     changes have been made to try to fix these, and ...
1498     (c) --disable-cpp can now be used to explicitly disable C++ support.
1500     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1501     backslash in a target when C++ was disabled. This confuses some
1502     versions of "make", apparently. Using an intermediate variable solves
1503     this. (Same for CPP_LOBJ.)
1505     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1506     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1507     necessary on certain architectures.
1509     4. Added a setting of -export-symbols-regex to the link command to remove
1510     those symbols that are exported in the C sense, but actually are local
1511     within the library, and not documented. Their names all begin with
1512     "_pcre_". This is not a perfect job, because (a) we have to except some
1513     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1514     available (and never for static libraries). I have made a note to try to
1515     find a way round (a) in the future.
1518 nigel 81 Version 6.2 01-Aug-05
1519     ---------------------
1521     1. There was no test for integer overflow of quantifier values. A construction
1522     such as {1111111111111111} would give undefined results. What is worse, if
1523     a minimum quantifier for a parenthesized subpattern overflowed and became
1524     negative, the calculation of the memory size went wrong. This could have
1525     led to memory overwriting.
1527     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1529     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1530     operating environments where this matters.
1532     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1533     PCRE options from within the C++ wrapper.
1535     5. Named capturing subpatterns were not being correctly counted when a pattern
1536     was compiled. This caused two problems: (a) If there were more than 100
1537     such subpatterns, the calculation of the memory needed for the whole
1538     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1539     back references of the form \12, where the number was greater than 9, were
1540     not recognized as back references, even though there were sufficient
1541     previous subpatterns.
1543     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1544     versions of gcc, e.g. 2.95.4.
1547 nigel 79 Version 6.1 21-Jun-05
1548     ---------------------
1550     1. There was one reference to the variable "posix" in pcretest.c that was not
1551     surrounded by "#if !defined NOPOSIX".
1553     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1554     the cross-check on the old pcre_info() function, for the benefit of the
1555     cut-down version of PCRE that is currently imported into Exim.
1557     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1558     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1559     patterns that start (?i) but I don't think that matters. The use of (?i) is
1560     just an example; this all applies to the other options as well.
1562     4. Since libtool seems to echo the compile commands it is issuing, the output
1563     from "make" can be reduced a bit by putting "@" in front of each libtool
1564     compile command.
1566     5. Patch from the folks at Google for configure.in to be a bit more thorough
1567     in checking for a suitable C++ installation before trying to compile the
1568     C++ stuff. This should fix a reported problem when a compiler was present,
1569     but no suitable headers.
1571     6. The man pages all had just "PCRE" as their title. I have changed them to
1572     be the relevant file name. I have also arranged that these names are
1573     retained in the file doc/pcre.txt, which is a concatenation in text format
1574     of all the man pages except the little individual ones for each function.
1576     7. The NON-UNIX-USE file had not been updated for the different set of source
1577     files that come with release 6. I also added a few comments about the C++
1578     wrapper.
1581 nigel 77 Version 6.0 07-Jun-05
1582     ---------------------
1584     1. Some minor internal re-organization to help with my DFA experiments.
1586     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1587     didn't matter for the library itself when fully configured, but did matter
1588     when compiling without UCP support, or within Exim, where the ucp files are
1589     not imported.
1591     3. Refactoring of the library code to split up the various functions into
1592     different source modules. The addition of the new DFA matching code (see
1593     below) to a single monolithic source would have made it really too
1594     unwieldy, quite apart from causing all the code to be include in a
1595     statically linked application, when only some functions are used. This is
1596     relevant even without the DFA addition now that patterns can be compiled in
1597     one application and matched in another.
1599     The downside of splitting up is that there have to be some external
1600     functions and data tables that are used internally in different modules of
1601     the library but which are not part of the API. These have all had their
1602     names changed to start with "_pcre_" so that they are unlikely to clash
1603     with other external names.
1605     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1606     a different (DFA) algorithm. Although it is slower than the original
1607     function, it does have some advantages for certain types of matching
1608     problem.
1610     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1611     including restarting after a partial match.
1613     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1614     defined when compiling for Windows was sent to me. I have put it into the
1615     code, though I have no means of testing or verifying it.
1617     7. Added the pcre_refcount() auxiliary function.
1619     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1620     match before or at the first newline in the subject string. In pcretest,
1621     the /f option on a pattern can be used to set this.
1623     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1624     would behave wrongly. This has been present in PCRE since release 4.0.
1626     10. A number of changes to the pcregrep command:
1628     (a) Refactored how -x works; insert ^(...)$ instead of setting
1629     PCRE_ANCHORED and checking the length, in preparation for adding
1630     something similar for -w.
1632     (b) Added the -w (match as a word) option.
1634     (c) Refactored the way lines are read and buffered so as to have more
1635     than one at a time available.
1637     (d) Implemented a pcregrep test script.
1639     (e) Added the -M (multiline match) option. This allows patterns to match
1640     over several lines of the subject. The buffering ensures that at least
1641     8K, or the rest of the document (whichever is the shorter) is available
1642     for matching (and similarly the previous 8K for lookbehind assertions).
1644     (f) Changed the --help output so that it now says
1646     -w, --word-regex(p)
1648     instead of two lines, one with "regex" and the other with "regexp"
1649     because that confused at least one person since the short forms are the
1650     same. (This required a bit of code, as the output is generated
1651     automatically from a table. It wasn't just a text change.)
1653     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1654     option but starts with a hyphen. Could be a pattern or a path name
1655     starting with a hyphen, for instance.
1657     (h) "-" can be given as a file name to represent stdin.
1659     (i) When file names are being printed, "(standard input)" is used for
1660     the standard input, for compatibility with GNU grep. Previously
1661     "<stdin>" was used.
1663     (j) The option --label=xxx can be used to supply a name to be used for
1664     stdin when file names are being printed. There is no short form.
1666     (k) Re-factored the options decoding logic because we are going to add
1667     two more options that take data. Such options can now be given in four
1668     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1670     (l) Added the -A, -B, and -C options for requesting that lines of context
1671     around matches be printed.
1673     (m) Added the -L option to print the names of files that do not contain
1674     any matching lines, that is, the complement of -l.
1676     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1677     continue to scan other files.
1679     (o) The -s option was incorrectly implemented. For compatibility with other
1680     greps, it now suppresses the error message for a non-existent or non-
1681     accessible file (but not the return code). There is a new option called
1682     -q that suppresses the output of matching lines, which was what -s was
1683     previously doing.
1685     (p) Added --include and --exclude options to specify files for inclusion
1686     and exclusion when recursing.
1688     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1689     Hopefully, it now does.
1691     12. Missing cast in pcre_study().
1693     13. Added an "uninstall" target to the makefile.
1695     14. Replaced "extern" in the function prototypes in Makefile.in with
1696     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1697     world, but is set differently for Windows.
1699     15. Added a second compiling function called pcre_compile2(). The only
1700     difference is that it has an extra argument, which is a pointer to an
1701     integer error code. When there is a compile-time failure, this is set
1702     non-zero, in addition to the error test pointer being set to point to an
1703     error message. The new argument may be NULL if no error number is required
1704     (but then you may as well call pcre_compile(), which is now just a
1705     wrapper). This facility is provided because some applications need a
1706     numeric error indication, but it has also enabled me to tidy up the way
1707     compile-time errors are handled in the POSIX wrapper.
1709     16. Added VPATH=.libs to the makefile; this should help when building with one
1710     prefix path and installing with another. (Or so I'm told by someone who
1711     knows more about this stuff than I do.)
1713     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1714     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1715     match everything, including newlines. This is not POSIX-compatible, but
1716     somebody wanted the feature. From pcretest it can be activated by using
1717     both the P and the s flags.
1719     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1721     19. libpcre.pc was being incorrectly installed as executable.
1723     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1724     it now also looks for '\r' so that it will work unmodified on Windows.
1726     21. Added Google's contributed C++ wrapper to the distribution.
1728     22. Added some untidy missing memory free() calls in pcretest, to keep
1729     Electric Fence happy when testing.
1733 nigel 75 Version 5.0 13-Sep-04
1734     ---------------------
1736     1. Internal change: literal characters are no longer packed up into items
1737     containing multiple characters in a single byte-string. Each character
1738     is now matched using a separate opcode. However, there may be more than one
1739     byte in the character in UTF-8 mode.
1741     2. The pcre_callout_block structure has two new fields: pattern_position and
1742     next_item_length. These contain the offset in the pattern to the next match
1743     item, and its length, respectively.
1745     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1746     insertion of callouts before each pattern item. Added the /C option to
1747     pcretest to make use of this.
1749     4. On the advice of a Windows user, the lines
1751     #if defined(_WIN32) || defined(WIN32)
1752     _setmode( _fileno( stdout ), 0x8000 );
1753     #endif /* defined(_WIN32) || defined(WIN32) */
1755     have been added to the source of pcretest. This apparently does useful
1756     magic in relation to line terminators.
1758     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1759     for the benefit of those environments where the "b" makes a difference.
1761     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1762     to know about it. I have put a hack into configure.in that adds in code
1763     to set GCC=yes if CC=icc. This seems to end up at a point in the
1764     generated configure script that is early enough to affect the setting of
1765     compiler options, which is what is needed, but I have no means of testing
1766     whether it really works. (The user who reported this had patched the
1767     generated configure script, which of course I cannot do.)
1769     LATER: After change 22 below (new libtool files), the configure script
1770     seems to know about icc (and also ecc). Therefore, I have commented out
1771     this hack in configure.in.
1773     7. Added support for pkg-config (2 patches were sent in).
1775     8. Negated POSIX character classes that used a combination of internal tables
1776     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1777     [[:^ascii]]. Typically, they would match almost any characters. The other
1778     POSIX classes were not broken in this way.
1780     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1781     to find the match, as PCRE was deluded into thinking that the match had to
1782     start at the start point or following a newline. The same bug applied to
1783     patterns with negative forward assertions or any backward assertions
1784     preceding ".*" at the start, unless the pattern required a fixed first
1785     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1787     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1788     starting at the last subject character, bytes beyond the end of the subject
1789     string were read.
1791     11. Renamed the variable "class" as "classbits" to make life easier for C++
1792     users. (Previously there was a macro definition, but it apparently wasn't
1793     enough.)
1795     12. Added the new field "tables" to the extra data so that tables can be passed
1796     in at exec time, or the internal tables can be re-selected. This allows
1797     a compiled regex to be saved and re-used at a later time by a different
1798     program that might have everything at different addresses.
1800     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1801     -R library as well as a -L library.
1803     14. The debugging options of pcretest (-d on the command line or D on a
1804     pattern) showed incorrect output for anything following an extended class
1805     that contained multibyte characters and which was followed by a quantifier.
1807     15. Added optional support for general category Unicode character properties
1808     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1809     support. It adds about 90K to the size of the library. The meanings of the
1810     inbuilt class escapes such as \d and \s have NOT been changed.
1812     16. Updated pcredemo.c to include calls to free() to release the memory for the
1813     compiled pattern.
1815     17. The generated file chartables.c was being created in the source directory
1816     instead of in the building directory. This caused the build to fail if the
1817     source directory was different from the building directory, and was
1818     read-only.
1820     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1821     file. No doubt somebody will tell me if they don't make sense... Also added
1822     Dan Mooney's comments about building on OpenVMS.
1824     19. Added support for partial matching via the PCRE_PARTIAL option for
1825     pcre_exec() and the \P data escape in pcretest.
1827     20. Extended pcretest with 3 new pattern features:
1829     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1830     write the compiled pattern to the file whose name is "rest-of-line".
1831     This is a straight binary dump of the data, with the saved pointer to
1832     the character tables forced to be NULL. The study data, if any, is
1833     written too. After writing, pcretest reads a new pattern.
1835     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1836     compiled pattern from the given file. There must not be any
1837     occurrences of "<" in the file name (pretty unlikely); if there are,
1838     pcretest will instead treat the initial "<" as a pattern delimiter.
1839     After reading in the pattern, pcretest goes on to read data lines as
1840     usual.
1842     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1843     and 16-bit fields in a compiled pattern, to simulate a pattern that
1844     was compiled on a host of opposite endianness.
1846     21. The pcre-exec() function can now cope with patterns that were compiled on
1847     hosts of opposite endianness, with this restriction:
1849     As for any compiled expression that is saved and used later, the tables
1850     pointer field cannot be preserved; the extra_data field in the arguments
1851     to pcre_exec() should be used to pass in a tables address if a value
1852     other than the default internal tables were used at compile time.
1854     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1855     now diagnosed as an error. Previously, most of the time, a negative number
1856     would have been treated as zero, but if in addition "ovector" was passed as
1857     NULL, a crash could occur.
1859     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1860     new versions from the libtool 1.5 distribution (the last one is a copy of
1861     a file called libtool.m4). This seems to have fixed the need to patch
1862     "configure" to support Darwin 1.3 (which I used to do). However, I still
1863     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1864     workstation).
1866     24. Changed the PCRE licence to be the more standard "BSD" licence.
1869 nigel 73 Version 4.5 01-Dec-03
1870     ---------------------
1872     1. There has been some re-arrangement of the code for the match() function so
1873     that it can be compiled in a version that does not call itself recursively.
1874     Instead, it keeps those local variables that need separate instances for
1875     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1876     needs to "recurse". Keeping track of where control must go is done by means
1877     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1878     hide most of the details from the main code, and operates only if
1879     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1880     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1881     operating.
1883     To make it easier for callers to provide specially tailored get/free
1884     functions for this usage, two new functions, pcre_stack_malloc, and
1885     pcre_stack_free, are used. They are always called in strict stacking order,
1886     and the size of block requested is always the same.
1888     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1889     PCRE has been compiled to use the stack or the heap for recursion. The
1890     -C option of pcretest uses this to show which version is compiled.
1892     A new data escape \S, is added to pcretest; it causes the amounts of store
1893     obtained and freed by both kinds of malloc/free at match time to be added
1894     to the output.
1896     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1897     what's available on my current Linux desktop machine.
1899     3. When matching a UTF-8 string, the test for a valid string at the start has
1900     been extended. If start_offset is not zero, PCRE now checks that it points
1901     to a byte that is the start of a UTF-8 character. If not, it returns
1902     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1903     this is necessary because there may be backward assertions in the pattern.
1904     When matching the same subject several times, it may save resources to use
1905     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1907     4. The code for checking the validity of UTF-8 strings has been tightened so
1908     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1909     containing "overlong sequences".
1911     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1912     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1913     should have been "&", but it just so happened that all the cases this let
1914     through by mistake were picked up later in the function.
1916     6. I had used a variable called "isblank" - this is a C99 function, causing
1917     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1919     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1920     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1921     so the version is shown; (c) stop "make test" echoing "./RunTest".
1923     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1925     9. The prototype for memmove() for systems that don't have it was using
1926     size_t, but the inclusion of the header that defines size_t was later. I've
1927     moved the #includes for the C headers earlier to avoid this.
1929     10. Added some adjustments to the code to make it easier to compiler on certain
1930     special systems:
1932     (a) Some "const" qualifiers were missing.
1933     (b) Added the macro EXPORT before all exported functions; by default this
1934     is defined to be empty.
1935     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1936     that it reads its output file name as an argument instead of writing
1937     to the standard output and assuming this can be redirected.
1939     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1940     class containing characters with values greater than 255, PCRE compilation
1941     went into a loop.
1943     12. A recursive reference to a subpattern that was within another subpattern
1944     that had a minimum quantifier of zero caused PCRE to crash. For example,
1945     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1946     recursion. If the recursively-called subpattern itself had a zero repeat,
1947     that was OK.
1949     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1950     buffer into which it was copied (for escape processing) was still set at
1951     1024, so long lines caused crashes.
1953     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1954     "internal error: code overflow...". This applied to any character class
1955     that was followed by a possessive quantifier.
1957     15. Modified the Makefile to add libpcre.la as a prerequisite for
1958     libpcreposix.la because I was told this is needed for a parallel build to
1959     work.
1961     16. If a pattern that contained .* following optional items at the start was
1962     studied, the wrong optimizing data was generated, leading to matching
1963     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1964     matching string must start with a or b or c. The correct conclusion for
1965     this pattern is that a match can start with any character.
1968 nigel 71 Version 4.4 13-Aug-03
1969     ---------------------
1971     1. In UTF-8 mode, a character class containing characters with values between
1972     127 and 255 was not handled correctly if the compiled pattern was studied.
1973     In fixing this, I have also improved the studying algorithm for such
1974     classes (slightly).
1976     2. Three internal functions had redundant arguments passed to them. Removal
1977     might give a very teeny performance improvement.
1979     3. Documentation bug: the value of the capture_top field in a callout is *one
1980     more than* the number of the hightest numbered captured substring.
1982     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1983     in incorrectly linking with a previously installed version. They now link
1984     explicitly with libpcre.la.
1986     5. configure.in no longer needs to recognize Cygwin specially.
1988     6. A problem in pcre.in for Windows platforms is fixed.
1990     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1991     pcretest, it used to include the size of the study block as part of its
1992     output. Unfortunately, the structure contains a field that has a different
1993     size on different hardware architectures. This meant that the tests that
1994     showed this size failed. As the block is currently always of a fixed size,
1995     this information isn't actually particularly useful in pcretest output, so
1996     I have just removed it.
1998     8. Three pre-processor statements accidentally did not start in column 1.
1999     Sadly, there are *still* compilers around that complain, even though
2000     standard C has not required this for well over a decade. Sigh.
2002     9. In pcretest, the code for checking callouts passed small integers in the
2003     callout_data field, which is a void * field. However, some picky compilers
2004     complained about the casts involved for this on 64-bit systems. Now
2005     pcretest passes the address of the small integer instead, which should get
2006     rid of the warnings.
2008     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2009     both compile and run time, and gives an error if an invalid UTF-8 sequence
2010     is found. There is a option for disabling this check in cases where the
2011     string is known to be correct and/or the maximum performance is wanted.
2013     11. In response to a bug report, I changed one line in Makefile.in from
2015     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2016     to
2017     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2019     to look similar to other lines, but I have no way of telling whether this
2020     is the right thing to do, as I do not use Windows. No doubt I'll get told
2021     if it's wrong...
2024 nigel 69 Version 4.3 21-May-03
2025     ---------------------
2027     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2028     Makefile.
2030     2. Some refactoring to improve the quality of the code:
2032     (i) The utf8_table... variables are now declared "const".
2034     (ii) The code for \cx, which used the "case flipping" table to upper case
2035     lower case letters, now just substracts 32. This is ASCII-specific,
2036     but the whole concept of \cx is ASCII-specific, so it seems
2037     reasonable.
2039     (iii) PCRE was using its character types table to recognize decimal and
2040     hexadecimal digits in the pattern. This is silly, because it handles
2041     only 0-9, a-f, and A-F, but the character types table is locale-
2042     specific, which means strange things might happen. A private
2043     table is now used for this - though it costs 256 bytes, a table is
2044     much faster than multiple explicit tests. Of course, the standard
2045     character types table is still used for matching digits in subject
2046     strings against \d.
2048     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2049     ending in _t are). So I've renamed it as ESC_tee.
2051     3. The first argument for regexec() in the POSIX wrapper should have been
2052     defined as "const".
2054     4. Changed pcretest to use malloc() for its buffers so that they can be
2055     Electric Fenced for debugging.
2057     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2058     to read one or more bytes before the start of the subject string. Often this
2059     had no effect on PCRE's behaviour, but in some circumstances it could
2060     provoke a segmentation fault.
2062     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2063     to try to read one or more bytes before the start of the subject string.
2065     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2066     UTF-8 support could misbehave in various ways if the subject string
2067     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2068     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2069     back over UTF-8 characters.)
2072 nigel 67 Version 4.2 14-Apr-03
2073     ---------------------
2075     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2077     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2078     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2079     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2080     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2081     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2082     and BUILD_EXEEXT
2083     Note: automatic setting of the BUILD variables is not yet working
2084     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2085     compile-time but not at link-time
2086     [LINK]: use for linking executables only
2087     make different versions for Windows and non-Windows
2088     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2089     libraries
2090     [LINK_FOR_BUILD]: new variable
2091     [OBJEXT]: use throughout
2092     [EXEEXT]: use throughout
2093     <winshared>: new target
2094     <wininstall>: new target
2095     <dftables.o>: use native compiler
2096     <dftables>: use native linker
2097     <install>: handle Windows platform correctly
2098     <clean>: ditto
2099     <check>: ditto
2100     copy DLL to top builddir before testing
2102     As part of these changes, -no-undefined was removed again. This was reported
2103     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2104     in any case.
2106     3. Some tidies to get rid of compiler warnings:
2108     . In the match_data structure, match_limit was an unsigned long int, whereas
2109     match_call_count was an int. I've made them both unsigned long ints.
2111     . In pcretest the fact that a const uschar * doesn't automatically cast to
2112     a void * provoked a warning.
2114     . Turning on some more compiler warnings threw up some "shadow" variables
2115     and a few more missing casts.
2117     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2118     option, a class that contained a single character with a value between 128
2119     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2121     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2122     option, a class that contained several characters, but with at least one
2123     whose value was between 128 and 255 caused PCRE to crash.
2126 nigel 65 Version 4.1 12-Mar-03
2127     ---------------------
2128 nigel 63
2129 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2130     needed, and a string in dftables.c that was longer than standard compilers are
2131     required to support.
2133     2. Compiling with Sun's compiler found a few more places where the code could
2134     be tidied up in order to avoid warnings.
2136     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2137     first of these names is deprecated in the latest Autoconf in favour of the name
2138     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2139     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2140     analogy I have changed it to CFLAGS_FOR_BUILD.
2142     4. Added -no-undefined to the linking command in the Makefile, because this is
2143     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2144     linking step for the pcreposix library.
2146     5. PCRE was failing to diagnose the case of two named groups with the same
2147     name.
2149     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2150     literal character that is needed in the subject for a match, and scans along to
2151     ensure that it is present before embarking on the full matching process. This
2152     saves time in cases of nested unlimited repeats that are never going to match.
2153     Problem: the scan can take a lot of time if the subject is very long (e.g.
2154     megabytes), thus penalizing straightforward matches. It is now done only if the
2155     amount of subject to be scanned is less than 1000 bytes.
2157     7. A lesser problem with the same optimization is that it was recording the
2158     first character of an anchored pattern as "needed", thus provoking a search
2159     right along the subject, even when the first match of the pattern was going to
2160     fail. The "needed" character is now not set for anchored patterns, unless it
2161     follows something in the pattern that is of non-fixed length. Thus, it still
2162     fulfils its original purpose of finding quick non-matches in cases of nested
2163     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2166     Version 4.0 17-Feb-03
2167     ---------------------
2169 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2170     extended to the end of string, PCRE compiled incorrect data. This could lead to
2171     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2173     2. Moved to autoconf 2.53 and libtool 1.4.2.
2175     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2176     the special perltest8 script is no longer needed - all the tests can be run
2177     from a single perltest script.
2179     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2180     by \s. It has now been removed in PCRE. This means it isn't recognized as
2181     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2182     class [:space:] *does* include VT, thereby creating a mess.
2184     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2185     space and tab.
2187     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2188     its new features into the main test script, reducing the number of scripts.
2190     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2191     were backward compatible, and made the (?i) apply to the whole pattern, as if
2192     /i were given. Now it behaves more logically, and applies the option setting
2193     only to what follows. PCRE has been changed to follow suit. However, if it
2194     finds options settings right at the start of the pattern, it extracts them into
2195     the global options, as before. Thus, they show up in the info data.
2197     8. Added support for the \Q...\E escape sequence. Characters in between are
2198     treated as literals. This is slightly different from Perl in that $ and @ are
2199     also handled as literals inside the quotes. In Perl, they will cause variable
2200     interpolation. Note the following examples:
2202     Pattern PCRE matches Perl matches
2204     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2205     \Qabc\$xyz\E abc\$xyz abc\$xyz
2206     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2208     For compatibility with Perl, \Q...\E sequences are recognized inside character
2209     classes as well as outside them.
2211     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2212     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2213     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2214     signed/unsigned warnings.
2216     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2217     option for pcretest, so I've replaced it by a simple function that does just
2218     that job.
2220     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2221     "pcregrep -".
2223     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2224     Java package. This provides some syntactic sugar for simple cases of what my
2225     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2226     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2227     item, you can use this simplified notation. Note that only makes sense with
2228     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2229     greediness, whatever the setting of the PCRE_UNGREEDY option.
2231     13. A change of greediness default within a pattern was not taking effect at
2232     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2233     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2234     was abstracted outside.
2236     14. PCRE now supports the \G assertion. It is true when the current matching
2237     position is at the start point of the match. This differs from \A when the
2238     starting offset is non-zero. Used with the /g option of pcretest (or similar
2239     code), it works in the same way as it does for Perl's /g option. If all
2240     alternatives of a regex begin with \G, the expression is anchored to the start
2241     match position, and the "anchored" flag is set in the compiled expression.
2243     15. Some bugs concerning the handling of certain option changes within patterns
2244     have been fixed. These applied to options other than (?ims). For example,
2245     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2246     been the other way round. Some of this was related to change 7 above.
2248     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2249     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2250     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2251     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2253     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2254     mode. Unlike ".", it always matches newline, whatever the setting of
2255     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2256     assertions. Perl allows it, but it doesn't (in general) work because it can't
2257     calculate the length of the lookbehind. At least, that's the case for Perl
2258     5.8.0 - I've been told they are going to document that it doesn't work in
2259     future.
2261     18. Added an error diagnosis for escapes that PCRE does not support: these are
2262     \L, \l, \N, \P, \p, \U, \u, and \X.
2264     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2265     reading past the end of the pattern in cases such as /[abcd/.
2267     20. PCRE was getting more memory than necessary for patterns with classes that
2268     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2270     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2271     compiling PCRE for use with Virtual Pascal.
2273     22. Small fix to the Makefile to make it work properly if the build is done
2274     outside the source tree.
2276     23. Added a new extension: a condition to go with recursion. If a conditional
2277     subpattern starts with (?(R) the "true" branch is used if recursion has
2278     happened, whereas the "false" branch is used only at the top level.
2280     24. When there was a very long string of literal characters (over 255 bytes
2281     without UTF support, over 250 bytes with UTF support), the computation of how
2282     much memory was required could be incorrect, leading to segfaults or other
2283     strange effects.
2285     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2286     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2287     there was a subsequent back reference to those brackets. This meant that, for
2288     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2289     possible to check for precisely this case. All we can do is abandon the
2290     optimization if .* occurs inside capturing brackets when there are any back
2291     references whatsoever. (See below for a better fix that came later.)
2293     26. The handling of the optimization for finding the first character of a
2294     non-anchored pattern, and for finding a character that is required later in the
2295     match were failing in some cases. This didn't break the matching; it just
2296     failed to optimize when it could. The way this is done has been re-implemented.
2298     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2300     28. Added a new feature that provides some of the functionality that Perl
2301     provides with (?{...}). The facility is termed a "callout". The way it is done
2302     in PCRE is for the caller to provide an optional function, by setting
2303     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2304     global variable. By default it is unset, which disables all calling out. To get
2305     the function called, the regex must include (?C) at appropriate points. This
2306     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2307     This provides a means of identifying different callout points. When PCRE
2308     reaches such a point in the regex, if pcre_callout has been set, the external
2309     function is called. It is provided with data in a structure called
2310     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2311     matching continues; if it returns a non-zero value, the match at the current
2312     point fails. However, backtracking will occur if possible. [This was changed
2313     later and other features added - see item 49 below.]
2315     29. pcretest is upgraded to test the callout functionality. It provides a
2316     callout function that displays information. By default, it shows the start of
2317     the match and the current position in the text. There are some new data escapes
2318     to vary what happens:
2320     \C+ in addition, show current contents of captured substrings
2321     \C- do not supply a callout function
2322     \C!n return 1 when callout number n is reached
2323     \C!n!m return 1 when callout number n is reached for the mth time
2325     30. If pcregrep was called with the -l option and just a single file name, it
2326     output "<stdin>" if a match was found, instead of the file name.
2328     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2329     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2330     pcre_exec(). This saves a malloc/free per call. The default value of
2331     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2332     when configuring.
2334     32. The default maximum size of a compiled pattern is 64K. There have been a
2335     few cases of people hitting this limit. The code now uses macros to handle the
2336     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2337     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2338     configuring. Tests 2 and 5 work only with 2-byte links because they output
2339     debugging information about compiled patterns.
2341     33. Internal code re-arrangements:
2343     (a) Moved the debugging function for printing out a compiled regex into
2344     its own source file (printint.c) and used #include to pull it into
2345     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2346     separate copies.
2348     (b) Defined the list of op-code names for debugging as a macro in
2349     internal.h so that it is next to the definition of the opcodes.
2351     (c) Defined a table of op-code lengths for simpler skipping along compiled
2352     code. This is again a macro in internal.h so that it is next to the
2353     definition of the opcodes.
2355     34. Added support for recursive calls to individual subpatterns, along the
2356     lines of Robin Houston's patch (but implemented somewhat differently).
2358     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2359     allow it to read and process whole directories in Win32. This code was
2360     contributed by Lionel Fourquaux; it has not been tested by me.
2362     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2363     used to name a group. Names consist of alphanumerics and underscores, and must
2364     be unique. Back references use the syntax (?P=name) and recursive calls use
2365     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2366     numbers. The function pcre_fullinfo() can be used after compilation to extract
2367     a name/number map. There are three relevant calls:
2369     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2370     PCRE_INFO_NAMECOUNT yields the number of entries
2371     PCRE_INFO_NAMETABLE yields a pointer to the map.
2373     The map is a vector of fixed-size entries. The size of each entry depends on
2374     the length of the longest name used. The first two bytes of each entry are the
2375     group number, most significant byte first. There follows the corresponding
2376     name, zero terminated. The names are in alphabetical order.
2378     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2379     case instead of 255. Making it the same both with and without UTF-8 support
2380     means that the same test output works with both.
2382     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2383     calling malloc() with a zero argument.
2385     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2386     optimization. I've improved things by keeping a bitmap of backreferences with
2387     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2388     fact referenced, the optimization can be applied. It is unlikely that a
2389     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2390     the match to follow \n) will appear inside brackets with a number greater than
2391     31, but if it does, any back reference > 31 suppresses the optimization.
2393     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2394     of disabling numbered capturing parentheses. Any opening parenthesis that is
2395     not followed by ? behaves as if it were followed by ?: but named parentheses
2396     can still be used for capturing (and they will acquire numbers in the usual
2397     way).
2399     41. Redesigned the return codes from the match() function into yes/no/error so
2400     that errors can be passed back from deep inside the nested calls. A malloc
2401     failure while inside a recursive subpattern call now causes the
2402     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2404     42. It is now possible to set a limit on the number of times the match()
2405     function is called in a call to pcre_exec(). This facility makes it possible to
2406     limit the amount of recursion and backtracking, though not in a directly
2407     obvious way, because the match() function is used in a number of different
2408     circumstances. The count starts from zero for each position in the subject
2409     string (for non-anchored patterns). The default limit is, for compatibility, a
2410     large number, namely 10 000 000. You can change this in two ways:
2412     (a) When configuring PCRE before making, you can use --with-match-limit=n
2413     to set a default value for the compiled library.
2415     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2416     a different value is set. See 45 below.
2418     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2420     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2421     of things that can be changed at compile time. The first argument specifies
2422     what is wanted and the second points to where the information is to be placed.
2423     The current list of available information is:
2427     The output is an integer that is set to one if UTF-8 support is available;
2428     otherwise it is set to zero.
2432     The output is an integer that it set to the value of the code that is used for
2433     newline. It is either LF (10) or CR (13).
2437     The output is an integer that contains the number of bytes used for internal
2438     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2442     The output is an integer that contains the threshold above which the POSIX
2443     interface uses malloc() for output vectors. See item 31 above.
2447     The output is an unsigned integer that contains the default limit of the number
2448     of match() calls in a pcre_exec() execution. See 42 above.
2450     44. pcretest has been upgraded by the addition of the -C option. This causes it
2451     to extract all the available output from the new pcre_config() function, and to
2452     output it. The program then exits immediately.
2454     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2455     order to support additional features. One way would have been to define
2456     pcre_exec2() (for example) with extra arguments, but this would not have been
2457     extensible, and would also have required all calls to the original function to
2458     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2459     is used for passing in "extra" data from pcre_study().
2461     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2462     contains the following fields:
2464     flags a bitmap indicating which of the following fields are set
2465     study_data opaque data from pcre_study()
2466     match_limit a way of specifying a limit on match() calls for a specific
2467     call to pcre_exec()
2468     callout_data data for callouts (see 49 below)
2470     The flag bits are also defined in pcre.h, and are
2476     The pcre_study() function now returns one of these new pcre_extra blocks, with
2477     the actual study data pointed to by the study_data field, and the
2478     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2479     before. That is, this change is entirely upwards-compatible and requires no
2480     change to existing code.
2482     If you want to pass in additional data to pcre_exec(), you can either place it
2483     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2484     block.
2486     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2487     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2488     times with different match limits, until it finds the minimum value needed for
2489     pcre_exec() to complete. The value is then output. This can be instructive; for
2490     most simple matches the number is quite small, but for pathological cases it
2491     gets very large very quickly.
2493     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2494     returns the size of the data block pointed to by the study_data field in a
2495     pcre_extra block, that is, the value that was passed as the argument to
2496     pcre_malloc() when PCRE was getting memory in which to place the information
2497     created by pcre_study(). The fourth argument should point to a size_t variable.
2498     pcretest has been extended so that this information is shown after a successful
2499     pcre_study() call when information about the compiled regex is being displayed.
2501     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2502     because what follows is always an absolute path. (Later: it turns out that this
2503     is more than cosmetic for MinGW, because it doesn't like empty path
2504     components.)
2506     49. Some changes have been made to the callout feature (see 28 above):
2508     (i) A callout function now has three choices for what it returns:
2510     0 => success, carry on matching
2511     > 0 => failure at this point, but backtrack if possible
2512     < 0 => serious error, return this value from pcre_exec()
2514     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2515     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2516     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2517     use by callout functions. It will never be used by PCRE itself.
2519     (ii) The pcre_extra structure (see 45 above) has a void * field called
2520     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2521     pcre_callout_block structure has a field of the same name. The contents of
2522     the field passed in the pcre_extra structure are passed to the callout
2523     function in the corresponding field in the callout block. This makes it
2524     easier to use the same callout-containing regex from multiple threads. For
2525     testing, the pcretest program has a new data escape
2527     \C*n pass the number n (may be negative) as callout_data
2529     If the callout function in pcretest receives a non-zero value as
2530     callout_data, it returns that value.
2532     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2533     there were some redundant $(CFLAGS) in commands that are now specified as
2534     $(LINK), which already includes $(CFLAGS).
2536     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2537     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2538     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2539     one-byte characters throughout. Note that case-insensitive matching applies
2540     only to characters whose values are less than 256. PCRE doesn't support the
2541     notion of cases for higher-valued characters.
2543     (i) A character class whose characters are all within 0-255 is handled as
2544     a bit map, and the map is inverted for negative classes. Previously, a
2545     character > 255 always failed to match such a class; however it should
2546     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2548     (ii) A negated character class with a single character < 255 is coded as
2549     "not this character" (OP_NOT). This wasn't working properly when the test
2550     character was multibyte, either singly or repeated.
2552     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2553     mode, for example: \x{100}{2,3}.
2555     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2556     singly or repeated) now correctly test multibyte characters. However,
2557     PCRE doesn't recognize any characters with values greater than 255 as
2558     digits, spaces, or word characters. Such characters always match \D, \S,
2559     and \W, and never match \d, \s, or \w.
2561     (v) Classes may now contain characters and character ranges with values
2562     greater than 255. For example: [ab\x{100}-\x{400}].
2564     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2565     PCRE in UTF-8 mode.
2567     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2568     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2569     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2570     value.)
2572     53. The single man page has become too large. I have therefore split it up into
2573     a number of separate man pages. These also give rise to individual HTML pages;
2574     these are now put in a separate directory, and there is an index.html page that
2575     lists them all. Some hyperlinking between the pages has been installed.
2577     54. Added convenience functions for handling named capturing parentheses.
2579     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2580     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2581     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2582     are faulted.
2584     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2585     calling configure. These values are used when compiling the dftables.c program
2586     which is run to generate the source of the default character tables. They
2587     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2588     you will need to set these values.
2590     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2593     Version 3.9 02-Jan-02
2594 nigel 61 ---------------------
2596     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2598     2. If --disable-static was given, the building process failed when trying to
2599     build pcretest and pcregrep. (For some reason it was using libtool to compile
2600     them, which is not right, as they aren't part of the library.)
2603 nigel 59 Version 3.8 18-Dec-01
2604     ---------------------
2606     1. The experimental UTF-8 code was completely screwed up. It was packing the
2607     bytes in the wrong order. How dumb can you get?
2610 nigel 57 Version 3.7 29-Oct-01
2611     ---------------------
2613     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2614     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2615     this didn't happen under Solaris 8, where I normally test things.
2617 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2618     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2619     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2620     this fix an hour or so after the initial 3.7 release.)
2621 nigel 57
2622 nigel 59
2623 nigel 55 Version 3.6 23-Oct-01
2624     ---------------------
2626     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2627     offsets passed as NULL with zero offset count.
2629     2. The config.guess and config.sub files had not been updated when I moved to
2630     the latest autoconf.
2633 nigel 53 Version 3.5 15-Aug-01
2634     ---------------------
2635 nigel 5
2636 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2637     had been forgotten.
2639     2. By using declared but undefined structures, we can avoid using "void"
2640     definitions in pcre.h while keeping the internal definitions of the structures
2641     private.
2643     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2644     user point of view, this means that both static and shared libraries are built
2645     by default, but this can be individually controlled. More of the work of
2646     handling this static/shared cases is now inside libtool instead of PCRE's make
2647     file.
2649     4. The pcretest utility is now installed along with pcregrep because it is
2650     useful for users (to test regexs) and by doing this, it automatically gets
2651     relinked by libtool. The documentation has been turned into a man page, so
2652     there are now .1, .txt, and .html versions in /doc.
2654     5. Upgrades to pcregrep:
2655     (i) Added long-form option names like gnu grep.
2656     (ii) Added --help to list all options with an explanatory phrase.
2657     (iii) Added -r, --recursive to recurse into sub-directories.
2658     (iv) Added -f, --file to read patterns from a file.
2660     6. pcre_exec() was referring to its "code" argument before testing that
2661     argument for NULL (and giving an error if it was NULL).
2663     7. Upgraded Makefile.in to allow for compiling in a different directory from
2664     the source directory.
2666     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2667     options bits, the pointer it was passed was to an int instead of to an unsigned
2668     long int. This mattered only on 64-bit systems.
2670     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2671     generated) instead of pcre.in, which it its source. Also made the same change
2672     in several of the .c files.
2674     10. A new release of gcc defines printf() as a macro, which broke pcretest
2675     because it had an ifdef in the middle of a string argument for printf(). Fixed
2676     by using separate calls to printf().
2678     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2679     script, to force use of CR or LF instead of \n in the source. On non-Unix
2680     systems, the value can be set in config.h.
2682     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2683     absolute limit. Changed the text of the error message to make this clear, and
2684     likewise updated the man page.
2686     13. The limit of 99 on the number of capturing subpatterns has been removed.
2687     The new limit is 65535, which I hope will not be a "real" limit.
2690 nigel 51 Version 3.4 22-Aug-00
2691     ---------------------
2693     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2695     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2698 nigel 49 Version 3.3 01-Aug-00
2699     ---------------------
2701     1. If an octal character was given, but the value was greater than \377, it
2702     was not getting masked to the least significant bits, as documented. This could
2703     lead to crashes in some systems.
2705     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2706     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2708     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2709     These just pass their arguments on to (pcre_free)(), but they are provided
2710     because some uses of PCRE bind it to non-C systems that can call its functions,
2711     but cannot call free() or pcre_free() directly.
2713     4. Add "make test" as a synonym for "make check". Corrected some comments in
2714     the Makefile.
2716     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2717     Makefile.
2719     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2720     command called pgrep for grepping around the active processes.
2722     7. Added the beginnings of support for UTF-8 character strings.
2724     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2725     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2726     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2727     out for the ar command.)
2730 nigel 47 Version 3.2 12-May-00
2731     ---------------------
2733     This is purely a bug fixing release.
2735     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2736     of ZA. This was just one example of several cases that could provoke this bug,
2737     which was introduced by change 9 of version 2.00. The code for breaking
2738     infinite loops after an iteration that matches an empty string was't working
2739     correctly.
2741     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2742     when matched against abbab (for example). After matching an empty string, it
2743     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2744     caused it to match further down the string than it should.
2746     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2747     was there because it doesn't seem to be needed, and it causes trouble on some
2748     systems, as it is not a Standard C header. It has been removed.
2750     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2751     were reported on the Macintosh. The changes were from
2753     while ((c = *(++ptr)) != 0 && c != '\n');
2754     to
2755     while ((c = *(++ptr)) != 0 && c != '\n') ;
2757     Totally extraordinary, but if that's what it takes...
2759     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2760     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2761     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2762     assumes the way PCRE uses memmove() (always moving upwards).
2764     6. PCRE is being used in one environment where strchr() is not available. There
2765     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2766     faster code anyway.
2769 nigel 45 Version 3.1 09-Feb-00
2770     ---------------------
2772     The only change in this release is the fixing of some bugs in Makefile.in for
2773     the "install" target:
2775     (1) It was failing to install pcreposix.h.
2777     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2780 nigel 43 Version 3.0 01-Feb-00
2781     ---------------------
2782 nigel 41
2783     1. Add support for the /+ modifier to perltest (to output $` like it does in
2784     pcretest).
2786     2. Add support for the /g modifier to perltest.
2788     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2789     matches null strings.
2791     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2792     pattern. Perl treats empty patterns specially - it reuses the most recent
2793     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2794     effect.
2796     5. The POSIX interface was broken in that it was just handing over the POSIX
2797     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2798     required a bigger vector, with some working space on the end. This means that
2799     the POSIX wrapper now has to get and free some memory, and copy the results.
2801 nigel 43 6. Added some simple autoconf support, placing the test data and the
2802     documentation in separate directories, re-organizing some of the
2803     information files, and making it build pcre-config (a GNU standard). Also added
2804     libtool support for building PCRE as a shared library, which is now the
2805     default.
2806 nigel 41
2807 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2808     09 are not valid octal constants. Single digits will be used for minor values
2809     less than 10.
2811     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2812     existing programs that set these in the POSIX interface can use PCRE without
2813     modification.
2815     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2816     return all that pcre_info() returns, plus additional data. The pcre_info()
2817     function is retained for compatibility, but is considered to be obsolete.
2819     10. Added experimental recursion feature (?R) to handle one common case that
2820     Perl 5.6 will be able to do with (?p{...}).
2822     11. Added support for POSIX character classes like [:alpha:], which Perl is
2823     adopting.
2826 nigel 39 Version 2.08 31-Aug-99
2827     ----------------------
2829     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2830     trying to match at the startoffset position, but instead was moving forward to
2831     the next newline as if a previous match had failed.
2833     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2834     and could get into a loop if a null string was matched other than at the start
2835     of the subject.
2837     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2838     be distinguished at compile time, and for completeness also added PCRE_DATE.
2840     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2841     in GnuWin32 environments.
2844 nigel 37 Version 2.07 29-Jul-99
2845     ----------------------
2847     1. The documentation is now supplied in plain text form and HTML as well as in
2848     the form of man page sources.
2850     2. C++ compilers don't like assigning (void *) values to other pointer types.
2851     In particular this affects malloc(). Although there is no problem in Standard
2852     C, I've put in casts to keep C++ compilers happy.
2854     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2855     should be (const char *).
2857     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2858     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2859     However, I haven't made this a standard facility. The documentation doesn't
2860     mention it, and the Makefile doesn't support it.
2862     5. The Makefile now contains an "install" target, with editable destinations at
2863     the top of the file. The pcretest program is not installed.
2865     6. pgrep -V now gives the PCRE version number and date.
2867     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2868     causing the entire string to be ignored, instead of just the last character.
2870     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2871     non-matching string, it can take a very, very long time, even for strings of
2872     quite modest length, because of the nested recursion. PCRE now does better in
2873     some of these cases. It does this by remembering the last required literal
2874     character in the pattern, and pre-searching the subject to ensure it is present
2875     before running the real match. In other words, it applies a heuristic to detect
2876     some types of certain failure quickly, and in the above example, if presented
2877     with a string that has no trailing " it gives "no match" very quickly.
2879     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2880     other alternatives are tried instead.
2883 nigel 35 Version 2.06 09-Jun-99
2884     ----------------------
2886     1. Change pcretest's output for amount of store used to show just the code
2887     space, because the remainder (the data block) varies in size between 32-bit and
2888     64-bit systems.
2890     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2891     start matching at. This allows lookbehinds to work when searching for multiple
2892     occurrences in a string.
2894     3. Added additional options to pcretest for testing multiple occurrences:
2896     /+ outputs the rest of the string that follows a match
2897     /g loops for multiple occurrences, using the new startoffset argument
2898     /G loops for multiple occurrences by passing an incremented pointer
2900     4. PCRE wasn't doing the "first character" optimization for patterns starting
2901     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2902     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2903     the letter 'x'. On long subject strings, this gives a significant speed-up.
2906 nigel 33 Version 2.05 21-Apr-99
2907     ----------------------
2909     1. Changed the type of magic_number from int to long int so that it works
2910     properly on 16-bit systems.
2912     2. Fixed a bug which caused patterns starting with .* not to work correctly
2913     when the subject string contained newline characters. PCRE was assuming
2914     anchoring for such patterns in all cases, which is not correct because .* will
2915     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2916     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2917     must be retried after every newline in the subject.
2920 nigel 31 Version 2.04 18-Feb-99
2921     ----------------------
2923     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2924     computation of the store needed to hold the pattern was incorrect (too large).
2925     If such patterns were nested a few deep, this could multiply and become a real
2926     problem.
2928     2. Added /M option to pcretest to show the memory requirement of a specific
2929     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2931     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2932     compiled in such a way that the backtracking after subsequent failure was
2933     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2934     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2937 nigel 29 Version 2.03 02-Feb-99
2938     ----------------------
2940     1. Fixed typo and small mistake in man page.
2942 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2943     LICENCE file containing the conditions.
2944 nigel 29
2945     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2946     Perl, that is the internal \ allows the delimiter to be included in the
2947     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2948     the final delimiter, add \ to the end of the pattern (to test the error).
2950     4. Added the convenience functions for extracting substrings after a successful
2951     match. Updated pcretest to make it able to test these functions.
2954 nigel 27 Version 2.02 14-Jan-99
2955     ----------------------
2957     1. Initialized the working variables associated with each extraction so that
2958     their saving and restoring doesn't refer to uninitialized store.
2960     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2961     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2962     fix the problem.
2964     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2965     calls, and wasn't printing the correct value for compiling calls. Increased the
2966     default value of LOOPREPEAT, and the number of significant figures in the
2967     times.
2969     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2971     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2972     a building problem on Windows NT with a FAT file system.
2975 nigel 25 Version 2.01 21-Oct-98
2976     ----------------------
2978     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2979     to character tables built by pcre_maketables() in the current locale. If NULL
2980     is passed, the default tables are used.
2983 nigel 23 Version 2.00 24-Sep-98
2984 nigel 21 ----------------------
2986 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2987     it any more.
2989     2. Allow quantification of (?>) groups, and make it work correctly.
2991     3. The first character computation wasn't working for (?>) groups.
2993     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2994     end of the subject) and add 5.005's \z, which really does match only at the
2995     very end of the subject.
2997     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2999     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3000     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3001     localized options. All options to pcre_study() were also removed.
3003     7. Add other new features from 5.005:
3005     $(?<= positive lookbehind
3006     $(?<! negative lookbehind
3007     (?imsx-imsx) added the unsetting capability
3008     such a setting is global if at outer level; local otherwise
3009     (?imsx-imsx:) non-capturing groups with option setting
3010     (?(cond)re|re) conditional pattern matching
3012     A backreference to itself in a repeated group matches the previous
3013     captured string.
3015     8. General tidying up of studying (both automatic and via "study")
3016     consequential on the addition of new assertions.
3018     9. As in 5.005, unlimited repeated groups that could match an empty substring
3019     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3020     runtime if any iteration does actually match an empty substring.
3022     10. Include the RunTest script in the distribution.
3024     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3025     discrepancies, some of which were old and were also with respect to 5.004. They
3026     have now been fixed.
3029     Version 1.09 28-Apr-98
3030     ----------------------
3032 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3033     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3034     program crashes, or just wrong answers. This did not apply to negated classes
3035     containing more than one character, or to minima other than one.
3038 nigel 19 Version 1.08 27-Mar-98
3039     ----------------------
3041     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3043     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3044     latter must appear before anything that relies on it in the pattern.
3047 nigel 17 Version 1.07 16-Feb-98
3048     ----------------------
3050     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3051     repeat of a potentially empty string).
3054 nigel 15 Version 1.06 23-Jan-98
3055     ----------------------
3057     1. Added Markus Oberhumer's little patches for C++.
3059     2. Literal strings longer than 255 characters were broken.
3062 nigel 13 Version 1.05 23-Dec-97
3063     ----------------------
3065     1. Negated character classes containing more than one character were failing if
3066     PCRE_CASELESS was set at run time.
3069 nigel 11 Version 1.04 19-Dec-97
3070     ----------------------
3072     1. Corrected the man page, where some "const" qualifiers had been omitted.
3074     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3075     input syntax.
3077     3. Fixed memory leak which occurred when a regex with back references was
3078     matched with an offsets vector that wasn't big enough. The temporary memory
3079     that is used in this case wasn't being freed if the match failed.
3081     4. Tidied pcretest to ensure it frees memory that it gets.
3083     5. Temporary memory was being obtained in the case where the passed offsets
3084     vector was exactly big enough.
3086     6. Corrected definition of offsetof() from change 5 below.
3088     7. I had screwed up change 6 below and broken the rules for the use of
3089     setjmp(). Now fixed.
3092 nigel 9 Version 1.03 18-Dec-97
3093     ----------------------
3095     1. A erroneous regex with a missing opening parenthesis was correctly
3096     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3097     on some systems.
3099     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3100     it was reported that one broken compiler failed on the former because "code" is
3101     also an independent variable.
3103     3. The erroneous regex a[]b caused an array overrun reference.
3105     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3106     fail on data ending with that character. (It was going on too far, and checking
3107     the next character, typically a binary zero.) This was specific to the
3108     optimized code for single-character negative classes.
3110     5. Added a contributed patch from the TIN world which does the following:
3112     + Add an undef for memmove, in case the the system defines a macro for it.
3114     + Add a definition of offsetof(), in case there isn't one. (I don't know
3115     the reason behind this - offsetof() is part of the ANSI standard - but
3116     it does no harm).
3118     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3119     most of the places where whitespace preceded '#'. I have given up and
3120     allowed the remaining 2 cases to be at the margin.
3122     + Rename some variables in pcre to eliminate shadowing. This seems very
3123     pedantic, but does no harm, of course.
3125     6. Moved the call to setjmp() into its own function, to get rid of warnings
3126     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3128     7. Constructs such as \d{8,} were compiling into the equivalent of
3129 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3130 nigel 9 outcome, but in this particular case used more store than had been allocated,
3131     which caused the bug to be discovered because it threw up an internal error.
3133     8. The debugging code in both pcre and pcretest for outputting the compiled
3134     form of a regex was going wrong in the case of back references followed by
3135     curly-bracketed repeats.
3138 nigel 7 Version 1.02 12-Dec-97
3139     ----------------------
3141     1. Typos in pcre.3 and comments in the source fixed.
3143     2. Applied a contributed patch to get rid of places where it used to remove
3144     'const' from variables, and fixed some signed/unsigned and uninitialized
3145     variable warnings.
3147     3. Added the "runtest" target to Makefile.
3149     4. Set default compiler flag to -O2 rather than just -O.
3152 nigel 5 Version 1.01 19-Nov-97
3153     ----------------------
3155     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3156     like /([ab]*)*/, that is, for classes with more than one character in them.
3158     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3159     as /((?>a*))*/ (a PCRE_EXTRA facility).
3162     Version 1.00 18-Nov-97
3163     ----------------------
3165     1. Added compile-time macros to support systems such as SunOS4 which don't have
3166     memmove() or strerror() but have other things that can be used instead.
3168     2. Arranged that "make clean" removes the executables.
3171 nigel 3 Version 0.99 27-Oct-97
3172     ----------------------
3174     1. Fixed bug in code for optimizing classes with only one character. It was
3175     initializing a 32-byte map regardless, which could cause it to run off the end
3176     of the memory it had got.
3178     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3181     Version 0.98 22-Oct-97
3182     ----------------------
3184     1. Fixed bug in code for handling temporary memory usage when there are more
3185     back references than supplied space in the ovector. This could cause segfaults.
3188     Version 0.97 21-Oct-97
3189     ----------------------
3191     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3193     2. Optimized negated single characters not to use a bit map.
3195     3. Brought error texts together as macro definitions; clarified some of them;
3196     fixed one that was wrong - it said "range out of order" when it meant "invalid
3197     escape sequence".
3199     4. Changed some char * arguments to const char *.
3201     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3203     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3204     pcretest.
3207     Version 0.96 16-Oct-97
3208     ----------------------
3210     1. Added a simple "pgrep" utility to the distribution.
3212     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3213     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3214     where "ddd" means "one or more decimal digits".
3216     3. Fixed serious bug. If a pattern had a back reference, but the call to
3217     pcre_exec() didn't supply a large enough ovector to record the related
3218     identifying subpattern, the match always failed. PCRE now remembers the number
3219     of the largest back reference, and gets some temporary memory in which to save
3220     the offsets during matching if necessary, in order to ensure that
3221     backreferences always work.
3223     4. Increased the compatibility with Perl in a number of ways:
3225     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3226     to request this handling. The option can be set at compile or exec time.
3228     (b) $ matches before a terminating newline by default; an option
3229     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3230     mode). The option can be set at compile or exec time.
3232     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3233     the same as Perl's. If the decimal number it represents is less than 10
3234     or there aren't that many previous left capturing parentheses, an octal
3235     escape is read. Inside a character class, it's always an octal escape,
3236     even if it is a single digit.
3238     (d) An escaped but undefined alphabetic character is taken as a literal,
3239     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3240     escapes.
3242     (e) {0} is now permitted. (The previous item is removed from the compiled
3243     pattern).
3245     5. Changed all the names of code files so that the basic parts are no longer
3246     than 10 characters, and abolished the teeny "globals.c" file.
3248     6. Changed the handling of character classes; they are now done with a 32-byte
3249     bit map always.
3251     7. Added the -d and /D options to pcretest to make it possible to look at the
3252     internals of compilation without having to recompile pcre.
3255     Version 0.95 23-Sep-97
3256     ----------------------
3258     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3259     \x20 at the start of a run of normal characters. These were being treated as
3260     real characters, instead of the source characters being re-checked.
3263     Version 0.94 18-Sep-97
3264     ----------------------
3266     1. The functions are now thread-safe, with the caveat that the global variables
3267     containing pointers to malloc() and free() or alternative functions are the
3268     same for all threads.
3270     2. Get pcre_study() to generate a bitmap of initial characters for non-
3271     anchored patterns when this is possible, and use it if passed to pcre_exec().
3274     Version 0.93 15-Sep-97
3275     ----------------------
3277     1. /(b)|(:+)/ was computing an incorrect first character.
3279     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3280     but not actually doing anything yet.
3282     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3283     as Perl does (e.g. [-az] or [az-]).
3285     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3286     all possible positions.
3288     5. Split up into different modules to avoid including unneeded functions in a
3289     compiled binary. However, compile and exec are still in one module. The "study"
3290     function is split off.
3292     6. The character tables are now in a separate module whose source is generated
3293     by an auxiliary program - but can then be edited by hand if required. There are
3294     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3295     toupper() in the code.
3297     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3298     make them global. Abolish the function for setting them, as the caller can now
3299     set them directly.
3302     Version 0.92 11-Sep-97
3303     ----------------------
3305     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3306     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3308     2. Caseless matching was not working in character classes if the characters in
3309     the pattern were in upper case.
3311     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3313     4. Make PCRE_ANCHORED public and accept as a compile option.
3315     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3316     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3317     pass them.
3319     6. Give an error if bad option bits passed at compile or run time.
3321     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3322     pcretest to cause it to pass that flag.
3324     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3325     options, and the first character, if set.
3327     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3330     Version 0.91 10-Sep-97
3331     ----------------------
3333     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3334     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3336     2. PCRE was looping on encountering an indefinitely repeated back reference to
3337     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3338     Perl does - treats the match as successful.
3340     ****


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