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Sun Mar 15 18:24:05 2009 UTC (6 years, 1 month ago) by ph10
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1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 376 Version 7.9 xx-xxx-09
5     ---------------------
7     1. When building with support for bzlib/zlib (pcregrep) and/or readline
8     (pcretest), all targets were linked against these libraries. This included
9     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
10     libraries. This caused unwanted dependencies to be created. This problem
11     has been fixed, and now only pcregrep is linked with bzlib/zlib and only
12     pcretest is linked with readline.
14     2. The "typedef int BOOL" in pcre_internal.h that was included inside the
15     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
16     moved outside it again, because FALSE and TRUE are already defined in AIX,
17     but BOOL is not.
19     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
20     PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.
22     4. The pcregrep documentation said spaces were inserted as well as colons (or
23     hyphens) following file names and line numbers when outputting matching
24     lines. This is not true; no spaces are inserted. I have also clarified the
25     wording for the --colour (or --color) option.
26 ph10 377
27 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
28     was not coloured; this is different to GNU grep, so I have changed it to be
29     the same.
31     6. When --colo(u)r was used in pcregrep, only the first matching substring in
32     each matching line was coloured. Now it goes on to look for further matches
33     of any of the test patterns, which is the same behaviour as GNU grep.
34 ph10 379
35     7. A pattern that could match an empty string could cause pcregrep to loop; it
36     doesn't make sense to accept an empty string match in pcregrep, so I have
37     locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38     seems to be how GNU grep behaves.
39 ph10 380
40     8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
41     start or after a newline", because the conditional assertion was not being
42 ph10 381 correctly handled. The rule now is that both the assertion and what follows
43     in the first alternative must satisfy the test.
45     9. If auto-callout was enabled in a pattern with a conditional group, PCRE
46     could crash during matching.
47 ph10 383
48     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
49     used for matching.
50 ph10 384
51     11. Unicode property support in character classes was not working for
52 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
53 ph10 386
54     12. Added the -M command line option to pcretest.
55 ph10 388
56     14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
57 ph10 389
58     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
59 ph10 376
61 ph10 374 Version 7.8 05-Sep-08
62 ph10 349 ---------------------
64     1. Replaced UCP searching code with optimized version as implemented for Ad
65     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
66 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
67     to 5 times on some simple patterns that I tested. Permission was given to
68     distribute the MultiStage2.py script that generates the tables (it's not in
69     the tarball, but is in the Subversion repository).
70 ph10 349
71 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
72     scripts.
73 ph10 358
74 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
75     a group with a zero qualifier. The result of the study could be incorrect,
76 ph10 358 or the function might crash, depending on the pattern.
78     4. Caseless matching was not working for non-ASCII characters in back
79 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
80 ph10 358 It now works when Unicode Property Support is available.
82 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
83     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
84     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
85 ph10 358 truncation.
86 ph10 349
87 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
89 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
90     pointers, in case they are 64-bit values.
91 ph10 371
92     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
93     test 2 if it fails.
95 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
96 ph10 371 and a #define of that name to empty if it is not externally set. This is to
97     allow users of MSVC to set it if necessary.
99     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
100 ph10 359 the convenience functions in the pcre_get.c source file.
101 ph10 371
102 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
103     could cause overwriting and/or a crash. This command provoked a crash in
104 ph10 371 some environments:
106     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
108 ph10 360 This potential security problem was recorded as CVE-2008-2371.
109 ph10 371
110 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
111     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
112 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
113 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
114     pcretest so that it places the subject at the end of its malloc-ed buffer.
115 ph10 371
116 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
117 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
119 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
120 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
121     first line. This applied both to normal and DFA matching.
123 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
124 ph10 371 /^[^d]*?$/8 failed to match "abc".
125 ph10 351
126 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
128     17. Make it more clear in the documentation that values returned from
129 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
130 ph10 357
131 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
132 ph10 368
133 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
134     supplied by Stefan Weber. I made a further small update for 7.8 because
135 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
136     replaced by pcre_ucd.c.
137 ph10 371
138 ph10 373
139 ph10 347 Version 7.7 07-May-08
140 ph10 321 ---------------------
142     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
143 ph10 345 a string to a long long, pretend we don't even have a long long." This is
144 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
145 ph10 345
146 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
147     pre-7.6 versions, which defined a global no_arg variable instead of putting
148 ph10 332 it in the RE class. (See also #8 below.)
149 ph10 345
150     3. Remove a line of dead code, identified by coverity and reported by Nuno
151     Lopes.
153 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
154 ph10 321
155 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
156 ph10 345 of files, instead of just to the final components.
158 ph10 324 (2) If there was more than one level of directory, the subdirectories were
159     skipped unless they satisfied the include/exclude conditions. This is
160     inconsistent with GNU grep (and could even be seen as contrary to the
161     pcregrep specification - which I improved to make it absolutely clear).
162     The action now is always to scan all levels of directory, and just
163     apply the include/exclude patterns to regular files.
164 ph10 345
165 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
166 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
168 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
169 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
170 ph10 326 doesn't support NULs in patterns.
171 ph10 345
172     7. Added some missing "const"s to declarations of static tables in
173     pcre_compile.c and pcre_dfa_exec.c.
175 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
176 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
177 ph10 345 first patch. And a third patch - this was a messy problem.)
178 ph10 321
179 ph10 345 9. Applied Craig's patch to remove the use of push_back().
181 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
182     matching function regexec().
183 ph10 345
184     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
185     which, however, unlike Perl's \g{...}, are subroutine calls, not back
186 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
187     Oniguruma does).
188 ph10 345
189     12. Previously, a group with a zero repeat such as (...){0} was completely
190 ph10 335 omitted from the compiled regex. However, this means that if the group
191     was called as a subroutine from elsewhere in the pattern, things went wrong
192 ph10 345 (an internal error was given). Such groups are now left in the compiled
193     pattern, with a new opcode that causes them to be skipped at execution
194 ph10 335 time.
195 ph10 345
196 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
197     to the way PCRE behaves:
198 ph10 345
199 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
200 ph10 345
201     (b) A back reference to an unmatched subpattern matches an empty string
202 ph10 336 (Perl fails the current match path).
203 ph10 345
204 ph10 341 (c) A data ] in a character class must be notated as \] because if the
205 ph10 345 first data character in a class is ], it defines an empty class. (In
206 ph10 341 Perl it is not possible to have an empty class.) The empty class []
207     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
208     The negative empty class [^] matches any one character, independently
209     of the DOTALL setting.
210 ph10 345
211     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
212 ph10 340 non-existent subpattern following a character class starting with ']' and
213     containing () gave an internal compiling error instead of "reference to
214     non-existent subpattern". Fortunately, when the pattern did exist, the
215 ph10 345 compiled code was correct. (When scanning forwards to check for the
216 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
217 ph10 345 the class, so got the count wrong. When actually compiling, the reference
218 ph10 340 was subsequently set up correctly.)
219 ph10 345
220 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
221 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
222     other assertions are supported. I have made pcre_dfa_exec() support
223     (*FAIL).
225 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
226 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
227     cannot be changed at match time, I realized I could make a small
228     improvement to matching performance by compiling OP_ALLANY instead of
229     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
230     on the OP_ANY path.
232     17. Compiling pcretest on Windows with readline support failed without the
233 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
234 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
236 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
237 ph10 345 ncurses library to be included for pcretest when ReadLine support is
238     requested, but also to allow for it to be overridden. This patch came from
239     Daniel Bergström.
240 ph10 347
241 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
242 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
243     any errors with the current Unicode tables. Thanks to Peter Kankowski for
244     spotting this.
245 ph10 324
246 ph10 332
247 ph10 319 Version 7.6 28-Jan-08
248 ph10 300 ---------------------
250 ph10 302 1. A character class containing a very large number of characters with
251     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
252     overflow.
253 ph10 309
254     2. Patch to cut out the "long long" test in pcrecpp_unittest when
255     HAVE_LONG_LONG is not defined.
257 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
258 ph10 304 bring them up to date and include new features. This patch includes:
259 ph10 309
260 ph10 304 - Fixed PH's badly added libz and libbz2 support.
261     - Fixed a problem with static linking.
262 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
263 ph10 304 - Fixed dftables problem and added an option.
264     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
266     - Added readline support for pcretest.
267 ph10 309 - Added an listing of the option settings after cmake has run.
269 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
270     "pcre.dll" under mingw when using Configure/Make. I added stuff to
271     Makefile.am that cause it to include this special target, without
272     affecting anything else. Note that the same mingw target plus all
273     the other distribution libraries and programs are now supported
274     when configuring with CMake (see 6 below) instead of with
275     Configure/Make.
276 ph10 309
277 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
278     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
279 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
280     solves the problem, but it does no harm.
281 ph10 313
282 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
283 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
284 ph10 314 with CMake, and also correct the comment about stack recursion.
285 ph10 313
286 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
287 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
288     of a program that users should build themselves after PCRE is installed, so
289     building it automatically is not really right. What is more, it gave
290 ph10 312 trouble in some build environments.
291 ph10 300
292 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
293 ph10 308
294 ph10 319
295 ph10 298 Version 7.5 10-Jan-08
296 ph10 263 ---------------------
298     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
299     values in parens when parsing an RE using the C++ wrapper."
300 ph10 286
301 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
302     Characters greater than 255 were excluded from the class instead of being
303     included.
304 ph10 286
305     3. The same bug as (2) above applied to negated POSIX classes such as
306 ph10 265 [:^space:].
307 ph10 286
308 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
309     defined or documented. It seems to have been a typo for PCRE_STATIC, so
310 ph10 286 I have changed it.
312 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
313 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
314     first named subpattern whose name started with "a" (in other words, the
315 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
316     expected" is now given for (?&) (a zero-length name), and this patch also
317     makes it give the same error for \k'' (previously it complained that that
318     was a reference to a non-existent subpattern).
319 ph10 286
320 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
321 ph10 286 this is right because (?- can be followed by option settings as well as by
322 ph10 269 digits. I have, however, made the messages clearer.
323 ph10 286
324 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
325     than the number used in the conditional) now cause a compile-time error.
326     This is actually not compatible with Perl, which accepts such patterns, but
327     treats the conditional as always being FALSE (as PCRE used to), but it
328     seems to me that giving a diagnostic is better.
329 ph10 286
330 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
331 ph10 275 and messages.
332 ph10 286
333     9. Fix two occurrences of "backslash" in comments that should have been
334     "backspace".
336     10. Remove two redundant lines of code that can never be obeyed (their function
337     was moved elsewhere).
339     11. The program that makes PCRE's Unicode character property table had a bug
340     which caused it to generate incorrect table entries for sequences of
341 ph10 277 characters that have the same character type, but are in different scripts.
342 ph10 286 It amalgamated them into a single range, with the script of the first of
343 ph10 277 them. In other words, some characters were in the wrong script. There were
344     thirteen such cases, affecting characters in the following ranges:
345 ph10 286
346 ph10 277 U+002b0 - U+002c1
347     U+0060c - U+0060d
348 ph10 286 U+0061e - U+00612
349 ph10 277 U+0064b - U+0065e
350     U+0074d - U+0076d
351     U+01800 - U+01805
352     U+01d00 - U+01d77
353     U+01d9b - U+01dbf
354     U+0200b - U+0200f
355     U+030fc - U+030fe
356     U+03260 - U+0327f
357     U+0fb46 - U+0fbb1
358     U+10450 - U+1049d
359 ph10 286
360 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
361     compatible with GNU grep in that, if there was more than one match in a
362     line, it showed only the first of them. It now behaves in the same way as
363     GNU grep.
364 ph10 286
365     13. If the -o and -v options were combined for pcregrep, it printed a blank
366     line for every non-matching line. GNU grep prints nothing, and pcregrep now
367     does the same. The return code can be used to tell if there were any
368     non-matching lines.
370 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
372     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
373 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
374 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
375     and both kinds of lookbehind were skipped).
377 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
378 ph10 284 inclusion of <windows.h> to before rather than after the definition of
379     INVALID_FILE_ATTRIBUTES (patch from David Byron).
380 ph10 263
381 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
382 ph10 286 character property caused pcre_compile() to compile bad code, which led at
383     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
384     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
385     caused the error; without that there was no problem.
386 ph10 263
387 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
388 ph10 286
389 ph10 289 19. Added --enable-pcretest-libreadline.
390 ph10 286
391 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
392 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
393 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
394     later patch that removed the other one (the right fix) and added unit tests
395     that check the return values (which was not done before).
396 ph10 292
397 ph10 291 21. Several CMake things:
398 ph10 287
399 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
400 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
401 ph10 288
402 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
403     linked with the newly-built libraries, not previously installed ones.
404 ph10 291
406 ph10 298
407     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
408     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
409     UTF-8 newline character). The key issue is that the pattern starts .*;
410     this means that the match must be either at the beginning, or after a
411     newline. The bug was in the code for advancing after a failed match and
412     checking that the new position followed a newline. It was not taking
413 ph10 294 account of UTF-8 characters correctly.
414 ph10 298
415     23. PCRE was behaving differently from Perl in the way it recognized POSIX
416     character classes. PCRE was not treating the sequence [:...:] as a
417     character class unless the ... were all letters. Perl, however, seems to
418     allow any characters between [: and :], though of course it rejects as
419     unknown any "names" that contain non-letters, because all the known class
420     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
421     for example, whereas PCRE did not - it did not recognize a POSIX character
422     class. This seemed a bit dangerous, so the code has been changed to be
423     closer to Perl. The behaviour is not identical to Perl, because PCRE will
424     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
425     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
426     Perl does, and where it didn't before.
428 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
429     Windows environments %n is disabled by default.
430 ph10 292
432 ph10 260 Version 7.4 21-Sep-07
433 ph10 230 ---------------------
435     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
436 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
437     LF". That isn't really right - the whole point of the change was to try to
438     help when there was an actual mention of one of the two characters. So now
439     the change happens only if \r or \n (or a literal CR or LF) character is
440 ph10 230 encountered.
441 ph10 231
442     2. The 32-bit options word was also used for 6 internal flags, but the numbers
443     of both had grown to the point where there were only 3 bits left.
444     Fortunately, there was spare space in the data structure, and so I have
445     moved the internal flags into a new 16-bit field to free up more option
446 ph10 230 bits.
447 ph10 231
448     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
449     but did not set the internal JCHANGED flag - either of these is enough to
450     control the way the "get" function works - but the PCRE_INFO_JCHANGED
451     facility is supposed to tell if (?J) was ever used, so now (?J) at the
452 ph10 230 start sets both bits.
454 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
455     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
456 ph10 230
457 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
459     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
460 ph10 233 compatibility, even though it is no longer used.
461 ph10 243
462     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
463 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
464 ph10 259 windows.h file is present (where different names are used). [This was
465 ph10 257 reversed later after testing - see 16 below.]
466 ph10 243
467     8. Changed all #include <config.h> to #include "config.h". There were also
468 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
469 ph10 243
470 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
471 ph10 243 sequence off the lines that it output.
473     10. It was pointed out to me that arrays of string pointers cause lots of
474     relocations when a shared library is dynamically loaded. A technique of
475     using a single long string with a table of offsets can drastically reduce
476     these. I have refactored PCRE in four places to do this. The result is
477 ph10 240 dramatic:
478 ph10 243
479 ph10 240 Originally: 290
480     After changing UCP table: 187
481 ph10 243 After changing error message table: 43
482 ph10 240 After changing table of "verbs" 36
483     After changing table of Posix names 22
484 ph10 243
485 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
486 ph10 247
487 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
488 ph10 247 unicode-properties was also set.
490 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
491 ph10 231
492 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
493     checked only for CRLF.
494 ph10 233
495 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
497 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
498 ph10 253
499 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
500 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
501     entirely. This removes changes made in 7 above.
502 ph10 256
503 ph10 261 17. The CMake files have been updated, and there is now more information about
504     building with CMake in the NON-UNIX-USE document.
505 ph10 257
506 ph10 261
507 ph10 228 Version 7.3 28-Aug-07
508 ph10 157 ---------------------
510 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
511     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
512     brackets there is not right, since it causes compilers to look for an
513     installed pcre.h, not the version that is in the source that is being
514     compiled (which of course may be different). I have changed it back to:
515 ph10 197
516 ph10 189 #include "pcre.h"
517 ph10 197
518     I have a vague recollection that the change was concerned with compiling in
519     different directories, but in the new build system, that is taken care of
520     by the VPATH setting the Makefile.
522 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
523     when the subject happened to end in the byte 0x85 (e.g. if the last
524     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
525     characters but of course it shouldn't be taken as a newline when it is part
526     of another character. The bug was that, for an unlimited repeat of . in
527     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
528     characters when looking for a newline.
529 ph10 197
530     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
532     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
533     in debug output.
535 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
536     long printing in the pcrecpp unittest when running under MinGW.
537 ph10 189
538 ph10 197 6. ESC_K was left out of the EBCDIC table.
539 ph10 189
540 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
541     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
542     limit also applies to "virtual nesting" when a pattern is recursive, and in
543     this case 1000 isn't so big. I have been able to remove this limit at the
544     expense of backing off one optimization in certain circumstances. Normally,
545     when pcre_exec() would call its internal match() function recursively and
546     immediately return the result unconditionally, it uses a "tail recursion"
547     feature to save stack. However, when a subpattern that can match an empty
548     string has an unlimited repetition quantifier, it no longer makes this
549     optimization. That gives it a stack frame in which to save the data for
550     checking that an empty string has been matched. Previously this was taken
551     from the 1000-entry workspace that had been reserved. So now there is no
552     explicit limit, but more stack is used.
553 ph10 189
554 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
555     syntax that is required for Windows, and which was going wrong for the
556     pcreposix and pcrecpp parts of the library. These were overlooked when this
557     problem was solved for the main library.
558 ph10 197
559 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
560     the size of patterns that contain repeated groups with explicit upper
561     limits. As the maximum quantifier is 65535, the maximum group length was
562     set at 30,000 so that the product of these two numbers did not overflow a
563     32-bit integer. However, it turns out that people want to use groups that
564     are longer than 30,000 bytes (though not repeat them that many times).
565     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
566     made it possible to implement the integer overflow checks in a much more
567     dynamic way, which I have now done. The artificial limitation on group
568     length has been removed - we now have only the limit on the total length of
569     the compiled pattern, which depends on the LINK_SIZE setting.
570 ph10 208
571     10. Fixed a bug in the documentation for get/copy named substring when
572     duplicate names are permitted. If none of the named substrings are set, the
573     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
574     empty string.
576     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
577     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
578     because the ] is interpreted as the first data character and the
579     terminating ] is not found. PCRE has been made compatible with Perl in this
580     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
581     cause memory overwriting.
583 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
584     string has been matched (to stop an infinite loop). It was not recognizing
585 ph10 208 a conditional subpattern that could match an empty string if that
586 ph10 206 subpattern was within another subpattern. For example, it looped when
587 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
588 ph10 206 condition was not nested. This bug has been fixed.
589 ph10 208
590 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
591     past the start of the subject in the presence of bytes with the top bit
592     set, for example "\x8aBCD".
593 ph10 211
594 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
595     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
596 ph10 200
597 ph10 211 14. Optimized (?!) to (*FAIL).
598 ph10 202
599 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
600     This restricts code points to be within the range 0 to 0x10FFFF, excluding
601     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
602     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
603     does: it's just the validity check that is more restrictive.
604 ph10 220
605     16. Inserted checks for integer overflows during escape sequence (backslash)
606     processing, and also fixed erroneous offset values for syntax errors during
607     backslash processing.
609 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
610 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
612 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
613     caused an overrun.
614 ph10 220
615     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
616     something other than just ASCII characters) inside a group that had an
617     unlimited repeat caused a loop at compile time (while checking to see
618     whether the group could match an empty string).
620 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
621     [\P{Any}] did so. (Error in the code for printing property names.)
622 ph10 210
623 ph10 220 21. An orphan \E inside a character class could cause a crash.
625     22. A repeated capturing bracket such as (A)? could cause a wild memory
626 ph10 218 reference during compilation.
627 ph10 220
628     23. There are several functions in pcre_compile() that scan along a compiled
629     expression for various reasons (e.g. to see if it's fixed length for look
630 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
631 ph10 220 present in the pattern. These operators have additional parameters compared
632     with \d, etc, and these were not being taken into account when moving along
633 ph10 218 the compiled data. Specifically:
634 ph10 220
635     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
636     length.
638     (b) An item such as \pL+ within a repeated group could cause crashes or
639 ph10 218 loops.
640 ph10 220
641 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
642 ph10 220 "reference to non-existent subpattern" error.
644 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
646 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
647 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
648 ph10 211
649 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
650 ph10 218
651 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
652 ph10 223 character were causing crashes (broken optimization).
653 ph10 227
654 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
655 ph10 227 \p or \P) caused a compile-time loop.
657 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
658     break. For example, the unstudied pattern [\r\n]A does not match the string
659     "\r\nA" because change 7.0/46 below moves the current point on by two
660     characters after failing to match at the start. However, the pattern \nA
661 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
662     the same is true. There doesn't seem any very clean way out of this, but
663     what I have chosen to do makes the common cases work: PCRE now takes note
664     of whether there can be an explicit match for \r or \n anywhere in the
665     pattern, and if so, 7.0/46 no longer applies. As part of this change,
666     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
667     pattern has explicit CR or LF references.
668 ph10 222
669 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
670 ph10 223
671 ph10 227
672 ph10 189 Version 7.2 19-Jun-07
673     ---------------------
675 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
676     which is apparently normally available under Windows.
677 ph10 159
678     2. Re-jig the pcregrep tests with different newline settings in an attempt
679     to make them independent of the local environment's newline setting.
680 ph10 157
681 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
682 ph10 165
683 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
684     was not 2, because the output contained actual offsets. The recent new
685 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
686     usable with all link sizes.
688 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
689     stack recursion. This gives a massive performance boost under BSD, but just
690 ph10 165 a small improvement under Linux. However, it saves one field in the frame
691 ph10 164 in all cases.
692 ph10 172
693 ph10 166 6. Added more features from the forthcoming Perl 5.10:
694 ph10 172
695 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
696     recursion call. It refers to the nth most recently opened parentheses.
697 ph10 172
698 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
699 ph10 172 to be opened parentheses.
701     (c) Conditions that refer to capturing parentheses can be specified
702 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
703 ph10 172
704 ph10 168 (d) \K resets the start of the current match so that everything before
705 ph10 172 is not part of it.
707 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
708 ph10 172
709 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
710 ph10 172 reference syntax.
711 ph10 182
712 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
713 ph10 182 alternative starts with the same number.
714 ph10 172
715 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
717 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
720     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
721     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
722 ph10 170 for detecting groups that can match an empty string.
723 ph10 159
724 ph10 172 9. A pattern with a very large number of alternatives (more than several
725     hundred) was running out of internal workspace during the pre-compile
726     phase, where pcre_compile() figures out how much memory will be needed. A
727     bit of new cunning has reduced the workspace needed for groups with
728     alternatives. The 1000-alternative test pattern now uses 12 bytes of
729     workspace instead of running out of the 4096 that are available.
730 ph10 182
731 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
732 ph10 172
733 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
734     The report of the bug said:
735 ph10 182
736 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
737     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
738 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
739 ph10 185
740 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
741 ph10 185 it matched the wrong number of bytes.
742 ph10 172
743 ph10 179
744 ph10 155 Version 7.1 24-Apr-07
745 ph10 98 ---------------------
747 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
748 ph10 122 that is more "standard", making use of automake and other Autotools. There
749 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
750     on this.
751 ph10 111
752     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
753     for recursive directory scanning broke on some systems because the files
754     are not scanned in any specific order and on different systems the order
755     was different. A call to "sort" has been inserted into RunGrepTest for the
756     approprate test as a short-term fix. In the longer term there may be an
757 ph10 100 alternative.
758 ph10 111
759 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
760 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
761     people do their own conversions for various reasons). The problems
762     concerned the use of low-level troff macros .br and .in. I have therefore
763     removed all such uses from the man pages (some were redundant, some could
764 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
765     HTML has been updated to handle .nf/.fi and to complain if it encounters
766     .br or .in.
767 ph10 111
768 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
769 ph10 123 arranged for config.h to be included in the distribution, with the name
770 ph10 111 config.h.generic, for the benefit of those who have to compile without
771     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
773     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
774     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
775 ph10 127 makevp.bat for the current PCRE, using the additional files
776 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
777 ph10 111
778     6. A Windows user reported a minor discrepancy with test 2, which turned out
779     to be caused by a trailing space on an input line that had got lost in his
780 ph10 102 copy. The trailing space was an accident, so I've just removed it.
781 ph10 111
782 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
783 ph10 111 that is needed.
785 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
786     as "const" (a) because they are and (b) because it helps the PHP
787     maintainers who have recently made a script to detect big data structures
788 ph10 111 in the php code that should be moved to the .rodata section. I remembered
789     to update Builducptable as well, so it won't revert if ucptable.h is ever
790 ph10 105 re-created.
791 ph10 111
792     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
793 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
794 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
795     support is not required. This saves 1.5-2K of code, which is important in
796 ph10 107 some applications.
797 ph10 111
798 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
799 ph10 111 so as not to refer to the tables, even though these functions will never be
800     called when UTF-8 support is disabled. Otherwise there are problems with a
801     shared library.
803 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
805     (a) It was defining its arguments as char * instead of void *.
807 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
808     a long time ago when I wrote it, but is no longer the case.
810 ph10 118 The emulated memove() is provided for those environments that have neither
811 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
812 ph10 118 is clearly not the case, as these two bugs were recently reported.
813 ph10 123
814 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
815 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
816     pages, and it removes trailing spaces from listed files. It also creates
817     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
818     case, it wraps all the #defines with #ifndefs. This script should be run
819 ph10 111 before "make dist".
820 ph10 123
821 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
822     with Unicode property support.
823 ph10 123
824     (a) For a maximizing quantifier, if the two different cases of the
825     character were of different lengths in their UTF-8 codings (there are
826     some cases like this - I found 11), and the matching function had to
827 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
828     were both the same length.
829 ph10 123
830     (b) When PCRE was configured to use the heap rather than the stack for
831     recursion during matching, it was not correctly preserving the data for
832     the other case of a UTF-8 character when checking ahead for a match
833     while processing a minimizing repeat. If the check also involved
834 ph10 115 matching a wide character, but failed, corruption could cause an
835     erroneous result when trying to check for a repeat of the original
836     character.
837 ph10 123
838 ph10 116 13. Some tidying changes to the testing mechanism:
839 ph10 98
840 ph10 116 (a) The RunTest script now detects the internal link size and whether there
841     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
842 ph10 123 values substituted by "configure". (The RunGrepTest script already did
843     this for UTF-8.) The configure.ac script no longer substitutes the
844     relevant variables.
846 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
847     with length and offset values. This means that the output is different
848     for different internal link sizes. Test 2 is skipped for link sizes
849     other than 2 because of this, bypassing the problem. Unfortunately,
850     there was also a test in test 3 (the locale tests) that used /B and
851 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
852     I have added a new /Z option to pcretest that replaces the length and
853     offset values with spaces. This is now used to make test 3 independent
854 ph10 122 of link size. (Test 2 will be tidied up later.)
855 ph10 123
856     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
857 ph10 122 segmentation fault instead of returning the appropriate error message.
858 ph10 134
859 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
860 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
861     This doesn't seem right; it now treats the CRLF combination as the line
862     ending, and so does not match in that case. It's only a pattern such as ^$
863     that would hit this one: something like ^ABC$ would have failed after \r
864     and then tried again after \r\n.
866 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
867 ph10 134 in an attempt to make files that differ only in their line terminators
868     compare equal. This works on Linux.
869 ph10 142
870 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
871     as it exited. This is now fixed, thanks to valgrind.
872 ph10 142
873 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
874 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
875     was because its rules for how to advance for /g after matching an empty
876 ph10 143 string at the end of a line did not allow for this case. They now check for
877     it specially.
878 ph10 150
879     20. pcretest is supposed to handle patterns and data of any length, by
880     extending its buffers when necessary. It was getting this wrong when the
881 ph10 147 buffer for a data line had to be extended.
882 ph10 150
883 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
884 ph10 150 CRLF as a newline sequence.
885 ph10 152
886 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
887 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
888     I have nevertheless tidied it up.
889 ph10 111
890 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
891 ph10 123
892 ph10 153 24. Added a man page for pcre-config.
893 ph10 152
894 ph10 153
895 nigel 93 Version 7.0 19-Dec-06
896     ---------------------
898     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
899     moving to gcc 4.1.1.
901     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
902     sys/time.h, which is documented as needed for this function. It doesn't
903     seem to matter on Linux, but it showed up on some releases of OS X.
905     3. It seems that there are systems where bytes whose values are greater than
906     127 match isprint() in the "C" locale. The "C" locale should be the
907     default when a C program starts up. In most systems, only ASCII printing
908     characters match isprint(). This difference caused the output from pcretest
909     to vary, making some of the tests fail. I have changed pcretest so that:
911     (a) When it is outputting text in the compiled version of a pattern, bytes
912     other than 32-126 are always shown as hex escapes.
914     (b) When it is outputting text that is a matched part of a subject string,
915     it does the same, unless a different locale has been set for the match
916     (using the /L modifier). In this case, it uses isprint() to decide.
918     4. Fixed a major bug that caused incorrect computation of the amount of memory
919     required for a compiled pattern when options that changed within the
920     pattern affected the logic of the preliminary scan that determines the
921     length. The relevant options are -x, and -i in UTF-8 mode. The result was
922     that the computed length was too small. The symptoms of this bug were
923     either the PCRE error "internal error: code overflow" from pcre_compile(),
924     or a glibc crash with a message such as "pcretest: free(): invalid next
925     size (fast)". Examples of patterns that provoked this bug (shown in
926     pcretest format) are:
928     /(?-x: )/x
929     /(?x)(?-x: \s*#\s*)/
930     /((?i)[\x{c0}])/8
931     /(?i:[\x{c0}])/8
933     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
934     is now done differently.
936     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
937     wrapper classes; (b) implement a new function in the C++ scanner that is
938     more efficient than the old way of doing things because it avoids levels of
939     recursion in the regex matching; (c) add a paragraph to the documentation
940     for the FullMatch() function.
942     6. The escape sequence \n was being treated as whatever was defined as
943     "newline". Not only was this contrary to the documentation, which states
944     that \n is character 10 (hex 0A), but it also went horribly wrong when
945     "newline" was defined as CRLF. This has been fixed.
947     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
948     was being set to -1 for the "end of line" case (supposedly a value that no
949     character can have). Though this value is never used (the check for end of
950     line is "zero bytes in current character"), it caused compiler complaints.
951     I've changed it to 0xffffffff.
953     8. In pcre_version.c, the version string was being built by a sequence of
954     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
955     string (as it is for production releases) called a macro with an empty
956     argument. The C standard says the result of this is undefined. The gcc
957     compiler treats it as an empty string (which was what was wanted) but it is
958     reported that Visual C gives an error. The source has been hacked around to
959     avoid this problem.
961     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
962     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
963     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
964     of them did).
966     10. Originally, pcretest opened its input and output without "b"; then I was
967     told that "b" was needed in some environments, so it was added for release
968     5.0 to both the input and output. (It makes no difference on Unix-like
969     systems.) Later I was told that it is wrong for the input on Windows. I've
970     now abstracted the modes into two macros, to make it easier to fiddle with
971     them, and removed "b" from the input mode under Windows.
973     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
975     12. Added -help and --help to pcretest as an official way of being reminded
976     of the options.
978     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
979     and pcrecpp.cc because they annoy compilers at high warning levels.
981     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
983     15. Fixed an occurrence of == in configure.ac that should have been = (shell
984     scripts are not C programs :-) and which was not noticed because it works
985     on Linux.
987     16. pcretest is supposed to handle any length of pattern and data line (as one
988     line or as a continued sequence of lines) by extending its input buffer if
989     necessary. This feature was broken for very long pattern lines, leading to
990     a string of junk being passed to pcre_compile() if the pattern was longer
991     than about 50K.
993     17. I have done a major re-factoring of the way pcre_compile() computes the
994     amount of memory needed for a compiled pattern. Previously, there was code
995     that made a preliminary scan of the pattern in order to do this. That was
996     OK when PCRE was new, but as the facilities have expanded, it has become
997     harder and harder to keep it in step with the real compile phase, and there
998     have been a number of bugs (see for example, 4 above). I have now found a
999     cunning way of running the real compile function in a "fake" mode that
1000     enables it to compute how much memory it would need, while actually only
1001     ever using a few hundred bytes of working memory and without too many
1002     tests of the mode. This should make future maintenance and development
1003     easier. A side effect of this work is that the limit of 200 on the nesting
1004     depth of parentheses has been removed (though this was never a serious
1005     limitation, I suspect). However, there is a downside: pcre_compile() now
1006     runs more slowly than before (30% or more, depending on the pattern). I
1007     hope this isn't a big issue. There is no effect on runtime performance.
1009     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1010     newline (only possible for the last line of a file) and it was a
1011     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1013     19. Added additional timing features to pcretest. (1) The -tm option now times
1014     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1015     separate command line item, by a number that specifies the number of
1016     repeats to use when timing. The default is 50000; this gives better
1017     precision, but takes uncomfortably long for very large patterns.
1019     20. Extended pcre_study() to be more clever in cases where a branch of a
1020     subpattern has no definite first character. For example, (a*|b*)[cd] would
1021     previously give no result from pcre_study(). Now it recognizes that the
1022     first character must be a, b, c, or d.
1024     21. There was an incorrect error "recursive call could loop indefinitely" if
1025     a subpattern (or the entire pattern) that was being tested for matching an
1026     empty string contained only one non-empty item after a nested subpattern.
1027     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1028     incorrectly, because the \d was being skipped in the check.
1030     22. The pcretest program now has a new pattern option /B and a command line
1031     option -b, which is equivalent to adding /B to every pattern. This causes
1032     it to show the compiled bytecode, without the additional information that
1033     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1034     is the same as /B/I).
1036     23. A new optimization is now able automatically to treat some sequences such
1037     as a*b as a*+b. More specifically, if something simple (such as a character
1038     or a simple class like \d) has an unlimited quantifier, and is followed by
1039     something that cannot possibly match the quantified thing, the quantifier
1040     is automatically "possessified".
1042     24. A recursive reference to a subpattern whose number was greater than 39
1043     went wrong under certain circumstances in UTF-8 mode. This bug could also
1044     have affected the operation of pcre_study().
1046     25. Realized that a little bit of performance could be had by replacing
1047     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1049     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1051     27. Possessive quantifiers such as a++ were previously implemented by turning
1052     them into atomic groups such as ($>a+). Now they have their own opcodes,
1053     which improves performance. This includes the automatically created ones
1054     from 23 above.
1056     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1057     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1058     the first matched character to be a colon. This applied both to named and
1059     numbered groups.
1061     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1063     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1064     building PCRE on Windows easier, so I have included it in the distribution.
1066     31. There is now a check in pcretest against a ridiculously large number being
1067     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1068     loop, the loop is abandoned.
1070     32. Forward references to subpatterns in conditions such as (?(2)...) where
1071     subpattern 2 is defined later cause pcre_compile() to search forwards in
1072     the pattern for the relevant set of parentheses. This search went wrong
1073     when there were unescaped parentheses in a character class, parentheses
1074     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1076     33. "Subroutine" calls and backreferences were previously restricted to
1077     referencing subpatterns earlier in the regex. This restriction has now
1078     been removed.
1080     34. Added a number of extra features that are going to be in Perl 5.10. On the
1081     whole, these are just syntactic alternatives for features that PCRE had
1082     previously implemented using the Python syntax or my own invention. The
1083     other formats are all retained for compatibility.
1085     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1086     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1087     also .NET compatible.
1089     (b) A recursion or subroutine call to a named group can now be defined as
1090     (?&name) as well as (?P>name).
1092     (c) A backreference to a named group can now be defined as \k<name> or
1093     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1094     5.10, are also .NET compatible.
1096     (d) A conditional reference to a named group can now use the syntax
1097     (?(<name>) or (?('name') as well as (?(name).
1099     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1100     groups (named and numbered) that are never evaluated inline, but can be
1101     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1102     is always false. There may be only one alternative in such a group.
1104     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1105     as the simple (?(R). The condition is true only if the most recent
1106     recursion is that of the given number or name. It does not search out
1107     through the entire recursion stack.
1109     (g) The escape \gN or \g{N} has been added, where N is a positive or
1110     negative number, specifying an absolute or relative reference.
1112     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1113     some "unreachable code" warnings.
1115     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1116     things, this adds five new scripts.
1118     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1119     There were also incompatibilities regarding the handling of \Q..\E inside
1120     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1121     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1123     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1124     matches an empty string, and forcibly breaks the loop. There were bugs in
1125     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1126     against aaaa the result was just "a" rather than "aaaa", for example. Two
1127     separate and independent bugs (that affected different cases) have been
1128     fixed.
1130     39. Refactored the code to abolish the use of different opcodes for small
1131     capturing bracket numbers. This is a tidy that I avoided doing when I
1132     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1133     The new approach is not only tidier, it makes it possible to reduce the
1134     memory needed to fix the previous bug (38).
1136     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1137     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1138     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1139     mode.
1141     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1142     report.
1144     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1145     copy construction and assignment in the C++ wrapper.
1147     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1148     couple of bugs that could have given wrong results in the "--newline=crlf"
1149     case.
1151     44. Added a number of casts and did some reorganization of signed/unsigned int
1152     variables following suggestions from Dair Grant. Also renamed the variable
1153     "this" as "item" because it is a C++ keyword.
1155     45. Arranged for dftables to add
1157     #include "pcre_internal.h"
1159     to pcre_chartables.c because without it, gcc 4.x may remove the array
1160     definition from the final binary if PCRE is built into a static library and
1161     dead code stripping is activated.
1163     46. For an unanchored pattern, if a match attempt fails at the start of a
1164     newline sequence, and the newline setting is CRLF or ANY, and the next two
1165     characters are CRLF, advance by two characters instead of one.
1168 nigel 91 Version 6.7 04-Jul-06
1169     ---------------------
1171     1. In order to handle tests when input lines are enormously long, pcretest has
1172     been re-factored so that it automatically extends its buffers when
1173     necessary. The code is crude, but this _is_ just a test program. The
1174     default size has been increased from 32K to 50K.
1176     2. The code in pcre_study() was using the value of the re argument before
1177     testing it for NULL. (Of course, in any sensible call of the function, it
1178     won't be NULL.)
1180     3. The memmove() emulation function in pcre_internal.h, which is used on
1181     systems that lack both memmove() and bcopy() - that is, hardly ever -
1182     was missing a "static" storage class specifier.
1184     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1185     containing an extended class (one that cannot be represented by a bitmap
1186     because it contains high-valued characters or Unicode property items, e.g.
1187     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1188     pattern, but PCRE should not loop if you do not (it no longer does).
1189     [Detail: two cases were found: (a) a repeated subpattern containing an
1190     extended class; (b) a recursive reference to a subpattern that followed a
1191     previous extended class. It wasn't skipping over the extended class
1192     correctly when UTF-8 mode was not set.]
1194     5. A negated single-character class was not being recognized as fixed-length
1195     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1196     compile error "lookbehind assertion is not fixed length".
1198     6. The RunPerlTest auxiliary script was showing an unexpected difference
1199     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1200     write a Perl script that can interpret lines of an input file either as
1201     byte characters or as UTF-8, which is what "perltest" was being required to
1202     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1203     can't do is switch easily at run time between having the "use utf8;" pragma
1204     or not. In the end, I fudged it by using the RunPerlTest script to insert
1205     "use utf8;" explicitly for the UTF-8 tests.
1207     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1208     the end of the subject string, contrary to the documentation and to what
1209     Perl does. This was true of both matching functions. Now it matches only at
1210     the start of the subject and immediately after *internal* newlines.
1212     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1213     a pointer to an int instead of a pointer to an unsigned long int. This
1214     caused problems on 64-bit systems.
1216     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1217     instance of the 'standard' template library not being so standard".
1219     10. There was no check on the number of named subpatterns nor the maximum
1220     length of a subpattern name. The product of these values is used to compute
1221     the size of the memory block for a compiled pattern. By supplying a very
1222     long subpattern name and a large number of named subpatterns, the size
1223     computation could be caused to overflow. This is now prevented by limiting
1224     the length of names to 32 characters, and the number of named subpatterns
1225     to 10,000.
1227     11. Subpatterns that are repeated with specific counts have to be replicated in
1228     the compiled pattern. The size of memory for this was computed from the
1229     length of the subpattern and the repeat count. The latter is limited to
1230     65535, but there was no limit on the former, meaning that integer overflow
1231     could in principle occur. The compiled length of a repeated subpattern is
1232     now limited to 30,000 bytes in order to prevent this.
1234     12. Added the optional facility to have named substrings with the same name.
1236     13. Added the ability to use a named substring as a condition, using the
1237     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1238     are numbers (not recommended). Forward references are permitted.
1240     14. Added forward references in named backreferences (if you see what I mean).
1242     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1243     pattern could run off the end of the subject. For example, the pattern
1244     "(?s)(.{1,5})"8 did this with the subject "ab".
1246     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1247     PCRE_CASELESS was set when matching characters that were quantified with ?
1248     or *.
1250     17. A character class other than a single negated character that had a minimum
1251     but no maximum quantifier - for example [ab]{6,} - was not handled
1252     correctly by pce_dfa_exec(). It would match only one character.
1254     18. A valid (though odd) pattern that looked like a POSIX character
1255     class but used an invalid character after [ (for example [[,abc,]]) caused
1256     pcre_compile() to give the error "Failed: internal error: code overflow" or
1257     in some cases to crash with a glibc free() error. This could even happen if
1258     the pattern terminated after [[ but there just happened to be a sequence of
1259     letters, a binary zero, and a closing ] in the memory that followed.
1261     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1262     over the years. Originally (before any Unicode support), just the bottom 8
1263     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1264     output from "man perlunicode" includes this:
1266     The regular expression compiler produces polymorphic opcodes. That
1267     is, the pattern adapts to the data and automatically switches to
1268     the Unicode character scheme when presented with Unicode data--or
1269     instead uses a traditional byte scheme when presented with byte
1270     data.
1272     Sadly, a wide octal escape does not cause a switch, and in a string with
1273     no other multibyte characters, these octal escapes are treated as before.
1274     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1275     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1276     Unicode string.
1278     I have not perpetrated such confusion in PCRE. Up till now, it took just
1279     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1280     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1281     translate to the appropriate multibyte character.
1283     29. Applied some refactoring to reduce the number of warnings from Microsoft
1284     and Borland compilers. This has included removing the fudge introduced
1285     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1286     a warning about an unused variable.
1288     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1289     characters since release 4.0, because Perl (from release 5.004) does not.
1290     [Or at least, is documented not to: some releases seem to be in conflict
1291     with the documentation.] However, when a pattern was studied with
1292     pcre_study() and all its branches started with \s, PCRE still included VT
1293     as a possible starting character. Of course, this did no harm; it just
1294     caused an unnecessary match attempt.
1296     22. Removed a now-redundant internal flag bit that recorded the fact that case
1297     dependency changed within the pattern. This was once needed for "required
1298     byte" processing, but is no longer used. This recovers a now-scarce options
1299     bit. Also moved the least significant internal flag bit to the most-
1300     significant bit of the word, which was not previously used (hangover from
1301     the days when it was an int rather than a uint) to free up another bit for
1302     the future.
1304     23. Added support for CRLF line endings as well as CR and LF. As well as the
1305     default being selectable at build time, it can now be changed at runtime
1306     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1307     specify that it is scanning data with non-default line endings.
1309     24. Changed the definition of CXXLINK to make it agree with the definition of
1310     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1312     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1313     recursions. This makes a big different to stack usage for some patterns.
1315     26. If a subpattern containing a named recursion or subroutine reference such
1316     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1317     the space required for the compiled pattern went wrong and gave too small a
1318     value. Depending on the environment, this could lead to "Failed: internal
1319     error: code overflow at offset 49" or "glibc detected double free or
1320     corruption" errors.
1322     27. Applied patches from Google (a) to support the new newline modes and (b) to
1323     advance over multibyte UTF-8 characters in GlobalReplace.
1325     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1326     difference for some implementation of PCRE in some Windows version.
1328     29. Added some extra testing facilities to pcretest:
1330     \q<number> in a data line sets the "match limit" value
1331     \Q<number> in a data line sets the "match recursion limt" value
1332     -S <number> sets the stack size, where <number> is in megabytes
1334     The -S option isn't available for Windows.
1337 nigel 89 Version 6.6 06-Feb-06
1338     ---------------------
1340     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1341     in pcreposix.h. I have copied the definition from pcre.h.
1343     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1344     because pcre.h is no longer a built file.
1346     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1347     not normally included in the compiled code.
1350 nigel 87 Version 6.5 01-Feb-06
1351     ---------------------
1353     1. When using the partial match feature with pcre_dfa_exec(), it was not
1354     anchoring the second and subsequent partial matches at the new starting
1355     point. This could lead to incorrect results. For example, with the pattern
1356     /1234/, partially matching against "123" and then "a4" gave a match.
1358     2. Changes to pcregrep:
1360     (a) All non-match returns from pcre_exec() were being treated as failures
1361     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1362     error message is output. Some extra information is given for the
1364     probably the only errors that are likely to be caused by users (by
1365     specifying a regex that has nested indefinite repeats, for instance).
1366     If there are more than 20 of these errors, pcregrep is abandoned.
1368     (b) A binary zero was treated as data while matching, but terminated the
1369     output line if it was written out. This has been fixed: binary zeroes
1370     are now no different to any other data bytes.
1372     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1373     used to set a locale for matching. The --locale=xxxx long option has
1374     been added (no short equivalent) to specify a locale explicitly on the
1375     pcregrep command, overriding the environment variables.
1377     (d) When -B was used with -n, some line numbers in the output were one less
1378     than they should have been.
1380     (e) Added the -o (--only-matching) option.
1382     (f) If -A or -C was used with -c (count only), some lines of context were
1383     accidentally printed for the final match.
1385     (g) Added the -H (--with-filename) option.
1387     (h) The combination of options -rh failed to suppress file names for files
1388     that were found from directory arguments.
1390     (i) Added the -D (--devices) and -d (--directories) options.
1392     (j) Added the -F (--fixed-strings) option.
1394     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1396     (l) Added the --colo(u)r option.
1398     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1399     is not present by default.
1401     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1402     items such as (?R) or (?1), when the recursion could match a number of
1403     alternatives. If it matched one of the alternatives, but subsequently,
1404     outside the recursion, there was a failure, the code tried to back up into
1405     the recursion. However, because of the way PCRE is implemented, this is not
1406     possible, and the result was an incorrect result from the match.
1408     In order to prevent this happening, the specification of recursion has
1409     been changed so that all such subpatterns are automatically treated as
1410     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1412     4. I had overlooked the fact that, in some locales, there are characters for
1413     which isalpha() is true but neither isupper() nor islower() are true. In
1414     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1415     and ordfeminine) are like this. This affected the treatment of \w and \W
1416     when they appeared in character classes, but not when they appeared outside
1417     a character class. The bit map for "word" characters is now created
1418     separately from the results of isalnum() instead of just taking it from the
1419     upper, lower, and digit maps. (Plus the underscore character, of course.)
1421     5. The above bug also affected the handling of POSIX character classes such as
1422     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1423     permanent tables. Instead, the bit maps for such a class were previously
1424     created as the appropriate unions of the upper, lower, and digit bitmaps.
1425     Now they are created by subtraction from the [[:word:]] class, which has
1426     its own bitmap.
1428     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1429     It is created by subtracting the vertical space characters (\x09, \x0a,
1430     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1431     subtraction was done in the overall bitmap for a character class, meaning
1432     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1433     be recognized. This bug has been fixed.
1435     7. Patches from the folks at Google:
1437     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1438     real life, but is still worth protecting against".
1440     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1441     regular expressions".
1443     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1444     have it.
1446     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1447     "configure" and the latter not, in order to fix a problem somebody had
1448     with compiling the Arg class on HP-UX.
1450     (e) Improve the error-handling of the C++ wrapper a little bit.
1452     (f) New tests for checking recursion limiting.
1454     8. The pcre_memmove() function, which is used only if the environment does not
1455     have a standard memmove() function (and is therefore rarely compiled),
1456     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1457     returning a result (though PCRE never actually uses the result).
1459     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1460     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1461     returned instead of calling malloc() with an overflowing number that would
1462     most likely cause subsequent chaos.
1464     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1466     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1467     with this option is matched, the nmatch and pmatch options of regexec() are
1468     ignored.
1470     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1471     provided in case anyone wants to the the POSIX interface with UTF-8
1472     strings.
1474     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1475     C++ linking (needed for some HP-UX environments).
1477     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1478     (unused parameter) and in the pcre_printint() function (omitted "default"
1479     switch label when the default is to do nothing).
1481     15. Added some code to make it possible, when PCRE is compiled as a C++
1482     library, to replace subject pointers for pcre_exec() with a smart pointer
1483     class, thus making it possible to process discontinuous strings.
1485     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1486     much the same function. They were added by different people who were trying
1487     to make PCRE easy to compile on non-Unix systems. It has been suggested
1488     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1489     for compiling on Windows systems. I have therefore replaced it with
1490     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1491     defaults to "extern" for C or "extern C" for C++, which works fine on
1492     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1493     SCOPE with something explicit in config.h. In addition:
1495     (a) pcreposix.h still had just "extern" instead of either of these macros;
1496     I have replaced it with PCRE_DATA_SCOPE.
1498     (b) Functions such as _pcre_xclass(), which are internal to the library,
1499     but external in the C sense, all had PCRE_EXPORT in their definitions.
1500     This is apparently wrong for the Windows case, so I have removed it.
1501     (It makes no difference on Unix-like systems.)
1503     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1504     of recursive calls to match(). This is different to MATCH_LIMIT because
1505     that limits the total number of calls to match(), not all of which increase
1506     the depth of recursion. Limiting the recursion depth limits the amount of
1507     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1508     when PCRE is compiled, and changed at run time. A patch from Google adds
1509     this functionality to the C++ interface.
1511     18. Changes to the handling of Unicode character properties:
1513     (a) Updated the table to Unicode 4.1.0.
1515     (b) Recognize characters that are not in the table as "Cn" (undefined).
1517     (c) I revised the way the table is implemented to a much improved format
1518     which includes recognition of ranges. It now supports the ranges that
1519     are defined in UnicodeData.txt, and it also amalgamates other
1520     characters into ranges. This has reduced the number of entries in the
1521     table from around 16,000 to around 3,000, thus reducing its size
1522     considerably. I realized I did not need to use a tree structure after
1523     all - a binary chop search is just as efficient. Having reduced the
1524     number of entries, I extended their size from 6 bytes to 8 bytes to
1525     allow for more data.
1527     (d) Added support for Unicode script names via properties such as \p{Han}.
1529     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1530     matching that character.
1532     20. When matching a repeated Unicode property with a minimum greater than zero,
1533     (for example \pL{2,}), PCRE could look past the end of the subject if it
1534     reached it while seeking the minimum number of characters. This could
1535     happen only if some of the characters were more than one byte long, because
1536     there is a check for at least the minimum number of bytes.
1538     21. Refactored the implementation of \p and \P so as to be more general, to
1539     allow for more different types of property in future. This has changed the
1540     compiled form incompatibly. Anybody with saved compiled patterns that use
1541     \p or \P will have to recompile them.
1543     22. Added "Any" and "L&" to the supported property types.
1545     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1546     but give a compile time error if the value is greater than 0xff.
1548     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1549     accidentally not being installed or uninstalled.
1551     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1552     made were to insert the current release number. This seemed silly, because
1553     it made things harder for people building PCRE on systems that don't run
1554     "configure". I have turned pcre.h into a distributed file, no longer built
1555     by "configure", with the version identification directly included. There is
1556     no longer a pcre.h.in file.
1558     However, this change necessitated a change to the pcre-config script as
1559     well. It is built from pcre-config.in, and one of the substitutions was the
1560     release number. I have updated configure.ac so that ./configure now finds
1561     the release number by grepping pcre.h.
1563     26. Added the ability to run the tests under valgrind.
1566 nigel 85 Version 6.4 05-Sep-05
1567     ---------------------
1569     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1570     "--" to be printed when multiple files were scanned, even when none of the
1571     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1572     consider it to be a bug, and have restored the previous behaviour.
1574     2. A couple of code tidies to get rid of compiler warnings.
1576     3. The pcretest program used to cheat by referring to symbols in the library
1577     whose names begin with _pcre_. These are internal symbols that are not
1578     really supposed to be visible externally, and in some environments it is
1579     possible to suppress them. The cheating is now confined to including
1580     certain files from the library's source, which is a bit cleaner.
1582     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1583     file's purpose clearer.
1585     5. Reorganized pcre_ucp_findchar().
1588 nigel 83 Version 6.3 15-Aug-05
1589     ---------------------
1591     1. The file libpcre.pc.in did not have general read permission in the tarball.
1593     2. There were some problems when building without C++ support:
1595     (a) If C++ support was not built, "make install" and "make test" still
1596     tried to test it.
1598     (b) There were problems when the value of CXX was explicitly set. Some
1599     changes have been made to try to fix these, and ...
1601     (c) --disable-cpp can now be used to explicitly disable C++ support.
1603     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1604     backslash in a target when C++ was disabled. This confuses some
1605     versions of "make", apparently. Using an intermediate variable solves
1606     this. (Same for CPP_LOBJ.)
1608     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1609     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1610     necessary on certain architectures.
1612     4. Added a setting of -export-symbols-regex to the link command to remove
1613     those symbols that are exported in the C sense, but actually are local
1614     within the library, and not documented. Their names all begin with
1615     "_pcre_". This is not a perfect job, because (a) we have to except some
1616     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1617     available (and never for static libraries). I have made a note to try to
1618     find a way round (a) in the future.
1621 nigel 81 Version 6.2 01-Aug-05
1622     ---------------------
1624     1. There was no test for integer overflow of quantifier values. A construction
1625     such as {1111111111111111} would give undefined results. What is worse, if
1626     a minimum quantifier for a parenthesized subpattern overflowed and became
1627     negative, the calculation of the memory size went wrong. This could have
1628     led to memory overwriting.
1630     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1632     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1633     operating environments where this matters.
1635     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1636     PCRE options from within the C++ wrapper.
1638     5. Named capturing subpatterns were not being correctly counted when a pattern
1639     was compiled. This caused two problems: (a) If there were more than 100
1640     such subpatterns, the calculation of the memory needed for the whole
1641     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1642     back references of the form \12, where the number was greater than 9, were
1643     not recognized as back references, even though there were sufficient
1644     previous subpatterns.
1646     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1647     versions of gcc, e.g. 2.95.4.
1650 nigel 79 Version 6.1 21-Jun-05
1651     ---------------------
1653     1. There was one reference to the variable "posix" in pcretest.c that was not
1654     surrounded by "#if !defined NOPOSIX".
1656     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1657     the cross-check on the old pcre_info() function, for the benefit of the
1658     cut-down version of PCRE that is currently imported into Exim.
1660     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1661     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1662     patterns that start (?i) but I don't think that matters. The use of (?i) is
1663     just an example; this all applies to the other options as well.
1665     4. Since libtool seems to echo the compile commands it is issuing, the output
1666     from "make" can be reduced a bit by putting "@" in front of each libtool
1667     compile command.
1669     5. Patch from the folks at Google for configure.in to be a bit more thorough
1670     in checking for a suitable C++ installation before trying to compile the
1671     C++ stuff. This should fix a reported problem when a compiler was present,
1672     but no suitable headers.
1674     6. The man pages all had just "PCRE" as their title. I have changed them to
1675     be the relevant file name. I have also arranged that these names are
1676     retained in the file doc/pcre.txt, which is a concatenation in text format
1677     of all the man pages except the little individual ones for each function.
1679     7. The NON-UNIX-USE file had not been updated for the different set of source
1680     files that come with release 6. I also added a few comments about the C++
1681     wrapper.
1684 nigel 77 Version 6.0 07-Jun-05
1685     ---------------------
1687     1. Some minor internal re-organization to help with my DFA experiments.
1689     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1690     didn't matter for the library itself when fully configured, but did matter
1691     when compiling without UCP support, or within Exim, where the ucp files are
1692     not imported.
1694     3. Refactoring of the library code to split up the various functions into
1695     different source modules. The addition of the new DFA matching code (see
1696     below) to a single monolithic source would have made it really too
1697     unwieldy, quite apart from causing all the code to be include in a
1698     statically linked application, when only some functions are used. This is
1699     relevant even without the DFA addition now that patterns can be compiled in
1700     one application and matched in another.
1702     The downside of splitting up is that there have to be some external
1703     functions and data tables that are used internally in different modules of
1704     the library but which are not part of the API. These have all had their
1705     names changed to start with "_pcre_" so that they are unlikely to clash
1706     with other external names.
1708     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1709     a different (DFA) algorithm. Although it is slower than the original
1710     function, it does have some advantages for certain types of matching
1711     problem.
1713     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1714     including restarting after a partial match.
1716     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1717     defined when compiling for Windows was sent to me. I have put it into the
1718     code, though I have no means of testing or verifying it.
1720     7. Added the pcre_refcount() auxiliary function.
1722     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1723     match before or at the first newline in the subject string. In pcretest,
1724     the /f option on a pattern can be used to set this.
1726     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1727     would behave wrongly. This has been present in PCRE since release 4.0.
1729     10. A number of changes to the pcregrep command:
1731     (a) Refactored how -x works; insert ^(...)$ instead of setting
1732     PCRE_ANCHORED and checking the length, in preparation for adding
1733     something similar for -w.
1735     (b) Added the -w (match as a word) option.
1737     (c) Refactored the way lines are read and buffered so as to have more
1738     than one at a time available.
1740     (d) Implemented a pcregrep test script.
1742     (e) Added the -M (multiline match) option. This allows patterns to match
1743     over several lines of the subject. The buffering ensures that at least
1744     8K, or the rest of the document (whichever is the shorter) is available
1745     for matching (and similarly the previous 8K for lookbehind assertions).
1747     (f) Changed the --help output so that it now says
1749     -w, --word-regex(p)
1751     instead of two lines, one with "regex" and the other with "regexp"
1752     because that confused at least one person since the short forms are the
1753     same. (This required a bit of code, as the output is generated
1754     automatically from a table. It wasn't just a text change.)
1756     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1757     option but starts with a hyphen. Could be a pattern or a path name
1758     starting with a hyphen, for instance.
1760     (h) "-" can be given as a file name to represent stdin.
1762     (i) When file names are being printed, "(standard input)" is used for
1763     the standard input, for compatibility with GNU grep. Previously
1764     "<stdin>" was used.
1766     (j) The option --label=xxx can be used to supply a name to be used for
1767     stdin when file names are being printed. There is no short form.
1769     (k) Re-factored the options decoding logic because we are going to add
1770     two more options that take data. Such options can now be given in four
1771     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1773     (l) Added the -A, -B, and -C options for requesting that lines of context
1774     around matches be printed.
1776     (m) Added the -L option to print the names of files that do not contain
1777     any matching lines, that is, the complement of -l.
1779     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1780     continue to scan other files.
1782     (o) The -s option was incorrectly implemented. For compatibility with other
1783     greps, it now suppresses the error message for a non-existent or non-
1784     accessible file (but not the return code). There is a new option called
1785     -q that suppresses the output of matching lines, which was what -s was
1786     previously doing.
1788     (p) Added --include and --exclude options to specify files for inclusion
1789     and exclusion when recursing.
1791     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1792     Hopefully, it now does.
1794     12. Missing cast in pcre_study().
1796     13. Added an "uninstall" target to the makefile.
1798     14. Replaced "extern" in the function prototypes in Makefile.in with
1799     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1800     world, but is set differently for Windows.
1802     15. Added a second compiling function called pcre_compile2(). The only
1803     difference is that it has an extra argument, which is a pointer to an
1804     integer error code. When there is a compile-time failure, this is set
1805     non-zero, in addition to the error test pointer being set to point to an
1806     error message. The new argument may be NULL if no error number is required
1807     (but then you may as well call pcre_compile(), which is now just a
1808     wrapper). This facility is provided because some applications need a
1809     numeric error indication, but it has also enabled me to tidy up the way
1810     compile-time errors are handled in the POSIX wrapper.
1812     16. Added VPATH=.libs to the makefile; this should help when building with one
1813     prefix path and installing with another. (Or so I'm told by someone who
1814     knows more about this stuff than I do.)
1816     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1817     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1818     match everything, including newlines. This is not POSIX-compatible, but
1819     somebody wanted the feature. From pcretest it can be activated by using
1820     both the P and the s flags.
1822     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1824     19. libpcre.pc was being incorrectly installed as executable.
1826     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1827     it now also looks for '\r' so that it will work unmodified on Windows.
1829     21. Added Google's contributed C++ wrapper to the distribution.
1831     22. Added some untidy missing memory free() calls in pcretest, to keep
1832     Electric Fence happy when testing.
1836 nigel 75 Version 5.0 13-Sep-04
1837     ---------------------
1839     1. Internal change: literal characters are no longer packed up into items
1840     containing multiple characters in a single byte-string. Each character
1841     is now matched using a separate opcode. However, there may be more than one
1842     byte in the character in UTF-8 mode.
1844     2. The pcre_callout_block structure has two new fields: pattern_position and
1845     next_item_length. These contain the offset in the pattern to the next match
1846     item, and its length, respectively.
1848     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1849     insertion of callouts before each pattern item. Added the /C option to
1850     pcretest to make use of this.
1852     4. On the advice of a Windows user, the lines
1854     #if defined(_WIN32) || defined(WIN32)
1855     _setmode( _fileno( stdout ), 0x8000 );
1856     #endif /* defined(_WIN32) || defined(WIN32) */
1858     have been added to the source of pcretest. This apparently does useful
1859     magic in relation to line terminators.
1861     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1862     for the benefit of those environments where the "b" makes a difference.
1864     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1865     to know about it. I have put a hack into configure.in that adds in code
1866     to set GCC=yes if CC=icc. This seems to end up at a point in the
1867     generated configure script that is early enough to affect the setting of
1868     compiler options, which is what is needed, but I have no means of testing
1869     whether it really works. (The user who reported this had patched the
1870     generated configure script, which of course I cannot do.)
1872     LATER: After change 22 below (new libtool files), the configure script
1873     seems to know about icc (and also ecc). Therefore, I have commented out
1874     this hack in configure.in.
1876     7. Added support for pkg-config (2 patches were sent in).
1878     8. Negated POSIX character classes that used a combination of internal tables
1879     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1880     [[:^ascii]]. Typically, they would match almost any characters. The other
1881     POSIX classes were not broken in this way.
1883     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1884     to find the match, as PCRE was deluded into thinking that the match had to
1885     start at the start point or following a newline. The same bug applied to
1886     patterns with negative forward assertions or any backward assertions
1887     preceding ".*" at the start, unless the pattern required a fixed first
1888     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1890     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1891     starting at the last subject character, bytes beyond the end of the subject
1892     string were read.
1894     11. Renamed the variable "class" as "classbits" to make life easier for C++
1895     users. (Previously there was a macro definition, but it apparently wasn't
1896     enough.)
1898     12. Added the new field "tables" to the extra data so that tables can be passed
1899     in at exec time, or the internal tables can be re-selected. This allows
1900     a compiled regex to be saved and re-used at a later time by a different
1901     program that might have everything at different addresses.
1903     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1904     -R library as well as a -L library.
1906     14. The debugging options of pcretest (-d on the command line or D on a
1907     pattern) showed incorrect output for anything following an extended class
1908     that contained multibyte characters and which was followed by a quantifier.
1910     15. Added optional support for general category Unicode character properties
1911     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1912     support. It adds about 90K to the size of the library. The meanings of the
1913     inbuilt class escapes such as \d and \s have NOT been changed.
1915     16. Updated pcredemo.c to include calls to free() to release the memory for the
1916     compiled pattern.
1918     17. The generated file chartables.c was being created in the source directory
1919     instead of in the building directory. This caused the build to fail if the
1920     source directory was different from the building directory, and was
1921     read-only.
1923     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1924     file. No doubt somebody will tell me if they don't make sense... Also added
1925     Dan Mooney's comments about building on OpenVMS.
1927     19. Added support for partial matching via the PCRE_PARTIAL option for
1928     pcre_exec() and the \P data escape in pcretest.
1930     20. Extended pcretest with 3 new pattern features:
1932     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1933     write the compiled pattern to the file whose name is "rest-of-line".
1934     This is a straight binary dump of the data, with the saved pointer to
1935     the character tables forced to be NULL. The study data, if any, is
1936     written too. After writing, pcretest reads a new pattern.
1938     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1939     compiled pattern from the given file. There must not be any
1940     occurrences of "<" in the file name (pretty unlikely); if there are,
1941     pcretest will instead treat the initial "<" as a pattern delimiter.
1942     After reading in the pattern, pcretest goes on to read data lines as
1943     usual.
1945     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1946     and 16-bit fields in a compiled pattern, to simulate a pattern that
1947     was compiled on a host of opposite endianness.
1949     21. The pcre-exec() function can now cope with patterns that were compiled on
1950     hosts of opposite endianness, with this restriction:
1952     As for any compiled expression that is saved and used later, the tables
1953     pointer field cannot be preserved; the extra_data field in the arguments
1954     to pcre_exec() should be used to pass in a tables address if a value
1955     other than the default internal tables were used at compile time.
1957     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1958     now diagnosed as an error. Previously, most of the time, a negative number
1959     would have been treated as zero, but if in addition "ovector" was passed as
1960     NULL, a crash could occur.
1962     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1963     new versions from the libtool 1.5 distribution (the last one is a copy of
1964     a file called libtool.m4). This seems to have fixed the need to patch
1965     "configure" to support Darwin 1.3 (which I used to do). However, I still
1966     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1967     workstation).
1969     24. Changed the PCRE licence to be the more standard "BSD" licence.
1972 nigel 73 Version 4.5 01-Dec-03
1973     ---------------------
1975     1. There has been some re-arrangement of the code for the match() function so
1976     that it can be compiled in a version that does not call itself recursively.
1977     Instead, it keeps those local variables that need separate instances for
1978     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1979     needs to "recurse". Keeping track of where control must go is done by means
1980     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1981     hide most of the details from the main code, and operates only if
1982     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1983     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1984     operating.
1986     To make it easier for callers to provide specially tailored get/free
1987     functions for this usage, two new functions, pcre_stack_malloc, and
1988     pcre_stack_free, are used. They are always called in strict stacking order,
1989     and the size of block requested is always the same.
1991     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1992     PCRE has been compiled to use the stack or the heap for recursion. The
1993     -C option of pcretest uses this to show which version is compiled.
1995     A new data escape \S, is added to pcretest; it causes the amounts of store
1996     obtained and freed by both kinds of malloc/free at match time to be added
1997     to the output.
1999     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2000     what's available on my current Linux desktop machine.
2002     3. When matching a UTF-8 string, the test for a valid string at the start has
2003     been extended. If start_offset is not zero, PCRE now checks that it points
2004     to a byte that is the start of a UTF-8 character. If not, it returns
2005     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2006     this is necessary because there may be backward assertions in the pattern.
2007     When matching the same subject several times, it may save resources to use
2008     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2010     4. The code for checking the validity of UTF-8 strings has been tightened so
2011     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2012     containing "overlong sequences".
2014     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2015     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2016     should have been "&", but it just so happened that all the cases this let
2017     through by mistake were picked up later in the function.
2019     6. I had used a variable called "isblank" - this is a C99 function, causing
2020     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2022     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2023     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2024     so the version is shown; (c) stop "make test" echoing "./RunTest".
2026     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2028     9. The prototype for memmove() for systems that don't have it was using
2029     size_t, but the inclusion of the header that defines size_t was later. I've
2030     moved the #includes for the C headers earlier to avoid this.
2032     10. Added some adjustments to the code to make it easier to compiler on certain
2033     special systems:
2035     (a) Some "const" qualifiers were missing.
2036     (b) Added the macro EXPORT before all exported functions; by default this
2037     is defined to be empty.
2038     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2039     that it reads its output file name as an argument instead of writing
2040     to the standard output and assuming this can be redirected.
2042     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2043     class containing characters with values greater than 255, PCRE compilation
2044     went into a loop.
2046     12. A recursive reference to a subpattern that was within another subpattern
2047     that had a minimum quantifier of zero caused PCRE to crash. For example,
2048     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2049     recursion. If the recursively-called subpattern itself had a zero repeat,
2050     that was OK.
2052     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2053     buffer into which it was copied (for escape processing) was still set at
2054     1024, so long lines caused crashes.
2056     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2057     "internal error: code overflow...". This applied to any character class
2058     that was followed by a possessive quantifier.
2060     15. Modified the Makefile to add libpcre.la as a prerequisite for
2061     libpcreposix.la because I was told this is needed for a parallel build to
2062     work.
2064     16. If a pattern that contained .* following optional items at the start was
2065     studied, the wrong optimizing data was generated, leading to matching
2066     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2067     matching string must start with a or b or c. The correct conclusion for
2068     this pattern is that a match can start with any character.
2071 nigel 71 Version 4.4 13-Aug-03
2072     ---------------------
2074     1. In UTF-8 mode, a character class containing characters with values between
2075     127 and 255 was not handled correctly if the compiled pattern was studied.
2076     In fixing this, I have also improved the studying algorithm for such
2077     classes (slightly).
2079     2. Three internal functions had redundant arguments passed to them. Removal
2080     might give a very teeny performance improvement.
2082     3. Documentation bug: the value of the capture_top field in a callout is *one
2083     more than* the number of the hightest numbered captured substring.
2085     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2086     in incorrectly linking with a previously installed version. They now link
2087     explicitly with libpcre.la.
2089     5. configure.in no longer needs to recognize Cygwin specially.
2091     6. A problem in pcre.in for Windows platforms is fixed.
2093     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2094     pcretest, it used to include the size of the study block as part of its
2095     output. Unfortunately, the structure contains a field that has a different
2096     size on different hardware architectures. This meant that the tests that
2097     showed this size failed. As the block is currently always of a fixed size,
2098     this information isn't actually particularly useful in pcretest output, so
2099     I have just removed it.
2101     8. Three pre-processor statements accidentally did not start in column 1.
2102     Sadly, there are *still* compilers around that complain, even though
2103     standard C has not required this for well over a decade. Sigh.
2105     9. In pcretest, the code for checking callouts passed small integers in the
2106     callout_data field, which is a void * field. However, some picky compilers
2107     complained about the casts involved for this on 64-bit systems. Now
2108     pcretest passes the address of the small integer instead, which should get
2109     rid of the warnings.
2111     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2112     both compile and run time, and gives an error if an invalid UTF-8 sequence
2113     is found. There is a option for disabling this check in cases where the
2114     string is known to be correct and/or the maximum performance is wanted.
2116     11. In response to a bug report, I changed one line in Makefile.in from
2118     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2119     to
2120     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2122     to look similar to other lines, but I have no way of telling whether this
2123     is the right thing to do, as I do not use Windows. No doubt I'll get told
2124     if it's wrong...
2127 nigel 69 Version 4.3 21-May-03
2128     ---------------------
2130     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2131     Makefile.
2133     2. Some refactoring to improve the quality of the code:
2135     (i) The utf8_table... variables are now declared "const".
2137     (ii) The code for \cx, which used the "case flipping" table to upper case
2138     lower case letters, now just substracts 32. This is ASCII-specific,
2139     but the whole concept of \cx is ASCII-specific, so it seems
2140     reasonable.
2142     (iii) PCRE was using its character types table to recognize decimal and
2143     hexadecimal digits in the pattern. This is silly, because it handles
2144     only 0-9, a-f, and A-F, but the character types table is locale-
2145     specific, which means strange things might happen. A private
2146     table is now used for this - though it costs 256 bytes, a table is
2147     much faster than multiple explicit tests. Of course, the standard
2148     character types table is still used for matching digits in subject
2149     strings against \d.
2151     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2152     ending in _t are). So I've renamed it as ESC_tee.
2154     3. The first argument for regexec() in the POSIX wrapper should have been
2155     defined as "const".
2157     4. Changed pcretest to use malloc() for its buffers so that they can be
2158     Electric Fenced for debugging.
2160     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2161     to read one or more bytes before the start of the subject string. Often this
2162     had no effect on PCRE's behaviour, but in some circumstances it could
2163     provoke a segmentation fault.
2165     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2166     to try to read one or more bytes before the start of the subject string.
2168     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2169     UTF-8 support could misbehave in various ways if the subject string
2170     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2171     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2172     back over UTF-8 characters.)
2175 nigel 67 Version 4.2 14-Apr-03
2176     ---------------------
2178     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2180     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2181     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2182     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2183     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2184     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2185     and BUILD_EXEEXT
2186     Note: automatic setting of the BUILD variables is not yet working
2187     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2188     compile-time but not at link-time
2189     [LINK]: use for linking executables only
2190     make different versions for Windows and non-Windows
2191     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2192     libraries
2193     [LINK_FOR_BUILD]: new variable
2194     [OBJEXT]: use throughout
2195     [EXEEXT]: use throughout
2196     <winshared>: new target
2197     <wininstall>: new target
2198     <dftables.o>: use native compiler
2199     <dftables>: use native linker
2200     <install>: handle Windows platform correctly
2201     <clean>: ditto
2202     <check>: ditto
2203     copy DLL to top builddir before testing
2205     As part of these changes, -no-undefined was removed again. This was reported
2206     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2207     in any case.
2209     3. Some tidies to get rid of compiler warnings:
2211     . In the match_data structure, match_limit was an unsigned long int, whereas
2212     match_call_count was an int. I've made them both unsigned long ints.
2214     . In pcretest the fact that a const uschar * doesn't automatically cast to
2215     a void * provoked a warning.
2217     . Turning on some more compiler warnings threw up some "shadow" variables
2218     and a few more missing casts.
2220     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2221     option, a class that contained a single character with a value between 128
2222     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2224     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2225     option, a class that contained several characters, but with at least one
2226     whose value was between 128 and 255 caused PCRE to crash.
2229 nigel 65 Version 4.1 12-Mar-03
2230     ---------------------
2231 nigel 63
2232 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2233     needed, and a string in dftables.c that was longer than standard compilers are
2234     required to support.
2236     2. Compiling with Sun's compiler found a few more places where the code could
2237     be tidied up in order to avoid warnings.
2239     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2240     first of these names is deprecated in the latest Autoconf in favour of the name
2241     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2242     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2243     analogy I have changed it to CFLAGS_FOR_BUILD.
2245     4. Added -no-undefined to the linking command in the Makefile, because this is
2246     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2247     linking step for the pcreposix library.
2249     5. PCRE was failing to diagnose the case of two named groups with the same
2250     name.
2252     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2253     literal character that is needed in the subject for a match, and scans along to
2254     ensure that it is present before embarking on the full matching process. This
2255     saves time in cases of nested unlimited repeats that are never going to match.
2256     Problem: the scan can take a lot of time if the subject is very long (e.g.
2257     megabytes), thus penalizing straightforward matches. It is now done only if the
2258     amount of subject to be scanned is less than 1000 bytes.
2260     7. A lesser problem with the same optimization is that it was recording the
2261     first character of an anchored pattern as "needed", thus provoking a search
2262     right along the subject, even when the first match of the pattern was going to
2263     fail. The "needed" character is now not set for anchored patterns, unless it
2264     follows something in the pattern that is of non-fixed length. Thus, it still
2265     fulfils its original purpose of finding quick non-matches in cases of nested
2266     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2269     Version 4.0 17-Feb-03
2270     ---------------------
2272 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2273     extended to the end of string, PCRE compiled incorrect data. This could lead to
2274     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2276     2. Moved to autoconf 2.53 and libtool 1.4.2.
2278     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2279     the special perltest8 script is no longer needed - all the tests can be run
2280     from a single perltest script.
2282     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2283     by \s. It has now been removed in PCRE. This means it isn't recognized as
2284     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2285     class [:space:] *does* include VT, thereby creating a mess.
2287     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2288     space and tab.
2290     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2291     its new features into the main test script, reducing the number of scripts.
2293     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2294     were backward compatible, and made the (?i) apply to the whole pattern, as if
2295     /i were given. Now it behaves more logically, and applies the option setting
2296     only to what follows. PCRE has been changed to follow suit. However, if it
2297     finds options settings right at the start of the pattern, it extracts them into
2298     the global options, as before. Thus, they show up in the info data.
2300     8. Added support for the \Q...\E escape sequence. Characters in between are
2301     treated as literals. This is slightly different from Perl in that $ and @ are
2302     also handled as literals inside the quotes. In Perl, they will cause variable
2303     interpolation. Note the following examples:
2305     Pattern PCRE matches Perl matches
2307     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2308     \Qabc\$xyz\E abc\$xyz abc\$xyz
2309     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2311     For compatibility with Perl, \Q...\E sequences are recognized inside character
2312     classes as well as outside them.
2314     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2315     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2316     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2317     signed/unsigned warnings.
2319     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2320     option for pcretest, so I've replaced it by a simple function that does just
2321     that job.
2323     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2324     "pcregrep -".
2326     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2327     Java package. This provides some syntactic sugar for simple cases of what my
2328     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2329     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2330     item, you can use this simplified notation. Note that only makes sense with
2331     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2332     greediness, whatever the setting of the PCRE_UNGREEDY option.
2334     13. A change of greediness default within a pattern was not taking effect at
2335     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2336     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2337     was abstracted outside.
2339     14. PCRE now supports the \G assertion. It is true when the current matching
2340     position is at the start point of the match. This differs from \A when the
2341     starting offset is non-zero. Used with the /g option of pcretest (or similar
2342     code), it works in the same way as it does for Perl's /g option. If all
2343     alternatives of a regex begin with \G, the expression is anchored to the start
2344     match position, and the "anchored" flag is set in the compiled expression.
2346     15. Some bugs concerning the handling of certain option changes within patterns
2347     have been fixed. These applied to options other than (?ims). For example,
2348     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2349     been the other way round. Some of this was related to change 7 above.
2351     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2352     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2353     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2354     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2356     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2357     mode. Unlike ".", it always matches newline, whatever the setting of
2358     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2359     assertions. Perl allows it, but it doesn't (in general) work because it can't
2360     calculate the length of the lookbehind. At least, that's the case for Perl
2361     5.8.0 - I've been told they are going to document that it doesn't work in
2362     future.
2364     18. Added an error diagnosis for escapes that PCRE does not support: these are
2365     \L, \l, \N, \P, \p, \U, \u, and \X.
2367     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2368     reading past the end of the pattern in cases such as /[abcd/.
2370     20. PCRE was getting more memory than necessary for patterns with classes that
2371     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2373     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2374     compiling PCRE for use with Virtual Pascal.
2376     22. Small fix to the Makefile to make it work properly if the build is done
2377     outside the source tree.
2379     23. Added a new extension: a condition to go with recursion. If a conditional
2380     subpattern starts with (?(R) the "true" branch is used if recursion has
2381     happened, whereas the "false" branch is used only at the top level.
2383     24. When there was a very long string of literal characters (over 255 bytes
2384     without UTF support, over 250 bytes with UTF support), the computation of how
2385     much memory was required could be incorrect, leading to segfaults or other
2386     strange effects.
2388     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2389     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2390     there was a subsequent back reference to those brackets. This meant that, for
2391     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2392     possible to check for precisely this case. All we can do is abandon the
2393     optimization if .* occurs inside capturing brackets when there are any back
2394     references whatsoever. (See below for a better fix that came later.)
2396     26. The handling of the optimization for finding the first character of a
2397     non-anchored pattern, and for finding a character that is required later in the
2398     match were failing in some cases. This didn't break the matching; it just
2399     failed to optimize when it could. The way this is done has been re-implemented.
2401     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2403     28. Added a new feature that provides some of the functionality that Perl
2404     provides with (?{...}). The facility is termed a "callout". The way it is done
2405     in PCRE is for the caller to provide an optional function, by setting
2406     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2407     global variable. By default it is unset, which disables all calling out. To get
2408     the function called, the regex must include (?C) at appropriate points. This
2409     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2410     This provides a means of identifying different callout points. When PCRE
2411     reaches such a point in the regex, if pcre_callout has been set, the external
2412     function is called. It is provided with data in a structure called
2413     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2414     matching continues; if it returns a non-zero value, the match at the current
2415     point fails. However, backtracking will occur if possible. [This was changed
2416     later and other features added - see item 49 below.]
2418     29. pcretest is upgraded to test the callout functionality. It provides a
2419     callout function that displays information. By default, it shows the start of
2420     the match and the current position in the text. There are some new data escapes
2421     to vary what happens:
2423     \C+ in addition, show current contents of captured substrings
2424     \C- do not supply a callout function
2425     \C!n return 1 when callout number n is reached
2426     \C!n!m return 1 when callout number n is reached for the mth time
2428     30. If pcregrep was called with the -l option and just a single file name, it
2429     output "<stdin>" if a match was found, instead of the file name.
2431     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2432     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2433     pcre_exec(). This saves a malloc/free per call. The default value of
2434     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2435     when configuring.
2437     32. The default maximum size of a compiled pattern is 64K. There have been a
2438     few cases of people hitting this limit. The code now uses macros to handle the
2439     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2440     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2441     configuring. Tests 2 and 5 work only with 2-byte links because they output
2442     debugging information about compiled patterns.
2444     33. Internal code re-arrangements:
2446     (a) Moved the debugging function for printing out a compiled regex into
2447     its own source file (printint.c) and used #include to pull it into
2448     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2449     separate copies.
2451     (b) Defined the list of op-code names for debugging as a macro in
2452     internal.h so that it is next to the definition of the opcodes.
2454     (c) Defined a table of op-code lengths for simpler skipping along compiled
2455     code. This is again a macro in internal.h so that it is next to the
2456     definition of the opcodes.
2458     34. Added support for recursive calls to individual subpatterns, along the
2459     lines of Robin Houston's patch (but implemented somewhat differently).
2461     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2462     allow it to read and process whole directories in Win32. This code was
2463     contributed by Lionel Fourquaux; it has not been tested by me.
2465     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2466     used to name a group. Names consist of alphanumerics and underscores, and must
2467     be unique. Back references use the syntax (?P=name) and recursive calls use
2468     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2469     numbers. The function pcre_fullinfo() can be used after compilation to extract
2470     a name/number map. There are three relevant calls:
2472     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2473     PCRE_INFO_NAMECOUNT yields the number of entries
2474     PCRE_INFO_NAMETABLE yields a pointer to the map.
2476     The map is a vector of fixed-size entries. The size of each entry depends on
2477     the length of the longest name used. The first two bytes of each entry are the
2478     group number, most significant byte first. There follows the corresponding
2479     name, zero terminated. The names are in alphabetical order.
2481     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2482     case instead of 255. Making it the same both with and without UTF-8 support
2483     means that the same test output works with both.
2485     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2486     calling malloc() with a zero argument.
2488     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2489     optimization. I've improved things by keeping a bitmap of backreferences with
2490     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2491     fact referenced, the optimization can be applied. It is unlikely that a
2492     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2493     the match to follow \n) will appear inside brackets with a number greater than
2494     31, but if it does, any back reference > 31 suppresses the optimization.
2496     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2497     of disabling numbered capturing parentheses. Any opening parenthesis that is
2498     not followed by ? behaves as if it were followed by ?: but named parentheses
2499     can still be used for capturing (and they will acquire numbers in the usual
2500     way).
2502     41. Redesigned the return codes from the match() function into yes/no/error so
2503     that errors can be passed back from deep inside the nested calls. A malloc
2504     failure while inside a recursive subpattern call now causes the
2505     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2507     42. It is now possible to set a limit on the number of times the match()
2508     function is called in a call to pcre_exec(). This facility makes it possible to
2509     limit the amount of recursion and backtracking, though not in a directly
2510     obvious way, because the match() function is used in a number of different
2511     circumstances. The count starts from zero for each position in the subject
2512     string (for non-anchored patterns). The default limit is, for compatibility, a
2513     large number, namely 10 000 000. You can change this in two ways:
2515     (a) When configuring PCRE before making, you can use --with-match-limit=n
2516     to set a default value for the compiled library.
2518     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2519     a different value is set. See 45 below.
2521     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2523     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2524     of things that can be changed at compile time. The first argument specifies
2525     what is wanted and the second points to where the information is to be placed.
2526     The current list of available information is:
2530     The output is an integer that is set to one if UTF-8 support is available;
2531     otherwise it is set to zero.
2535     The output is an integer that it set to the value of the code that is used for
2536     newline. It is either LF (10) or CR (13).
2540     The output is an integer that contains the number of bytes used for internal
2541     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2545     The output is an integer that contains the threshold above which the POSIX
2546     interface uses malloc() for output vectors. See item 31 above.
2550     The output is an unsigned integer that contains the default limit of the number
2551     of match() calls in a pcre_exec() execution. See 42 above.
2553     44. pcretest has been upgraded by the addition of the -C option. This causes it
2554     to extract all the available output from the new pcre_config() function, and to
2555     output it. The program then exits immediately.
2557     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2558     order to support additional features. One way would have been to define
2559     pcre_exec2() (for example) with extra arguments, but this would not have been
2560     extensible, and would also have required all calls to the original function to
2561     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2562     is used for passing in "extra" data from pcre_study().
2564     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2565     contains the following fields:
2567     flags a bitmap indicating which of the following fields are set
2568     study_data opaque data from pcre_study()
2569     match_limit a way of specifying a limit on match() calls for a specific
2570     call to pcre_exec()
2571     callout_data data for callouts (see 49 below)
2573     The flag bits are also defined in pcre.h, and are
2579     The pcre_study() function now returns one of these new pcre_extra blocks, with
2580     the actual study data pointed to by the study_data field, and the
2581     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2582     before. That is, this change is entirely upwards-compatible and requires no
2583     change to existing code.
2585     If you want to pass in additional data to pcre_exec(), you can either place it
2586     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2587     block.
2589     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2590     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2591     times with different match limits, until it finds the minimum value needed for
2592     pcre_exec() to complete. The value is then output. This can be instructive; for
2593     most simple matches the number is quite small, but for pathological cases it
2594     gets very large very quickly.
2596     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2597     returns the size of the data block pointed to by the study_data field in a
2598     pcre_extra block, that is, the value that was passed as the argument to
2599     pcre_malloc() when PCRE was getting memory in which to place the information
2600     created by pcre_study(). The fourth argument should point to a size_t variable.
2601     pcretest has been extended so that this information is shown after a successful
2602     pcre_study() call when information about the compiled regex is being displayed.
2604     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2605     because what follows is always an absolute path. (Later: it turns out that this
2606     is more than cosmetic for MinGW, because it doesn't like empty path
2607     components.)
2609     49. Some changes have been made to the callout feature (see 28 above):
2611     (i) A callout function now has three choices for what it returns:
2613     0 => success, carry on matching
2614     > 0 => failure at this point, but backtrack if possible
2615     < 0 => serious error, return this value from pcre_exec()
2617     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2618     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2619     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2620     use by callout functions. It will never be used by PCRE itself.
2622     (ii) The pcre_extra structure (see 45 above) has a void * field called
2623     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2624     pcre_callout_block structure has a field of the same name. The contents of
2625     the field passed in the pcre_extra structure are passed to the callout
2626     function in the corresponding field in the callout block. This makes it
2627     easier to use the same callout-containing regex from multiple threads. For
2628     testing, the pcretest program has a new data escape
2630     \C*n pass the number n (may be negative) as callout_data
2632     If the callout function in pcretest receives a non-zero value as
2633     callout_data, it returns that value.
2635     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2636     there were some redundant $(CFLAGS) in commands that are now specified as
2637     $(LINK), which already includes $(CFLAGS).
2639     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2640     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2641     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2642     one-byte characters throughout. Note that case-insensitive matching applies
2643     only to characters whose values are less than 256. PCRE doesn't support the
2644     notion of cases for higher-valued characters.
2646     (i) A character class whose characters are all within 0-255 is handled as
2647     a bit map, and the map is inverted for negative classes. Previously, a
2648     character > 255 always failed to match such a class; however it should
2649     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2651     (ii) A negated character class with a single character < 255 is coded as
2652     "not this character" (OP_NOT). This wasn't working properly when the test
2653     character was multibyte, either singly or repeated.
2655     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2656     mode, for example: \x{100}{2,3}.
2658     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2659     singly or repeated) now correctly test multibyte characters. However,
2660     PCRE doesn't recognize any characters with values greater than 255 as
2661     digits, spaces, or word characters. Such characters always match \D, \S,
2662     and \W, and never match \d, \s, or \w.
2664     (v) Classes may now contain characters and character ranges with values
2665     greater than 255. For example: [ab\x{100}-\x{400}].
2667     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2668     PCRE in UTF-8 mode.
2670     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2671     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2672     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2673     value.)
2675     53. The single man page has become too large. I have therefore split it up into
2676     a number of separate man pages. These also give rise to individual HTML pages;
2677     these are now put in a separate directory, and there is an index.html page that
2678     lists them all. Some hyperlinking between the pages has been installed.
2680     54. Added convenience functions for handling named capturing parentheses.
2682     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2683     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2684     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2685     are faulted.
2687     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2688     calling configure. These values are used when compiling the dftables.c program
2689     which is run to generate the source of the default character tables. They
2690     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2691     you will need to set these values.
2693     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2696     Version 3.9 02-Jan-02
2697 nigel 61 ---------------------
2699     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2701     2. If --disable-static was given, the building process failed when trying to
2702     build pcretest and pcregrep. (For some reason it was using libtool to compile
2703     them, which is not right, as they aren't part of the library.)
2706 nigel 59 Version 3.8 18-Dec-01
2707     ---------------------
2709     1. The experimental UTF-8 code was completely screwed up. It was packing the
2710     bytes in the wrong order. How dumb can you get?
2713 nigel 57 Version 3.7 29-Oct-01
2714     ---------------------
2716     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2717     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2718     this didn't happen under Solaris 8, where I normally test things.
2720 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2721     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2722     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2723     this fix an hour or so after the initial 3.7 release.)
2724 nigel 57
2725 nigel 59
2726 nigel 55 Version 3.6 23-Oct-01
2727     ---------------------
2729     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2730     offsets passed as NULL with zero offset count.
2732     2. The config.guess and config.sub files had not been updated when I moved to
2733     the latest autoconf.
2736 nigel 53 Version 3.5 15-Aug-01
2737     ---------------------
2738 nigel 5
2739 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2740     had been forgotten.
2742     2. By using declared but undefined structures, we can avoid using "void"
2743     definitions in pcre.h while keeping the internal definitions of the structures
2744     private.
2746     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2747     user point of view, this means that both static and shared libraries are built
2748     by default, but this can be individually controlled. More of the work of
2749     handling this static/shared cases is now inside libtool instead of PCRE's make
2750     file.
2752     4. The pcretest utility is now installed along with pcregrep because it is
2753     useful for users (to test regexs) and by doing this, it automatically gets
2754     relinked by libtool. The documentation has been turned into a man page, so
2755     there are now .1, .txt, and .html versions in /doc.
2757     5. Upgrades to pcregrep:
2758     (i) Added long-form option names like gnu grep.
2759     (ii) Added --help to list all options with an explanatory phrase.
2760     (iii) Added -r, --recursive to recurse into sub-directories.
2761     (iv) Added -f, --file to read patterns from a file.
2763     6. pcre_exec() was referring to its "code" argument before testing that
2764     argument for NULL (and giving an error if it was NULL).
2766     7. Upgraded Makefile.in to allow for compiling in a different directory from
2767     the source directory.
2769     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2770     options bits, the pointer it was passed was to an int instead of to an unsigned
2771     long int. This mattered only on 64-bit systems.
2773     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2774     generated) instead of pcre.in, which it its source. Also made the same change
2775     in several of the .c files.
2777     10. A new release of gcc defines printf() as a macro, which broke pcretest
2778     because it had an ifdef in the middle of a string argument for printf(). Fixed
2779     by using separate calls to printf().
2781     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2782     script, to force use of CR or LF instead of \n in the source. On non-Unix
2783     systems, the value can be set in config.h.
2785     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2786     absolute limit. Changed the text of the error message to make this clear, and
2787     likewise updated the man page.
2789     13. The limit of 99 on the number of capturing subpatterns has been removed.
2790     The new limit is 65535, which I hope will not be a "real" limit.
2793 nigel 51 Version 3.4 22-Aug-00
2794     ---------------------
2796     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2798     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2801 nigel 49 Version 3.3 01-Aug-00
2802     ---------------------
2804     1. If an octal character was given, but the value was greater than \377, it
2805     was not getting masked to the least significant bits, as documented. This could
2806     lead to crashes in some systems.
2808     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2809     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2811     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2812     These just pass their arguments on to (pcre_free)(), but they are provided
2813     because some uses of PCRE bind it to non-C systems that can call its functions,
2814     but cannot call free() or pcre_free() directly.
2816     4. Add "make test" as a synonym for "make check". Corrected some comments in
2817     the Makefile.
2819     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2820     Makefile.
2822     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2823     command called pgrep for grepping around the active processes.
2825     7. Added the beginnings of support for UTF-8 character strings.
2827     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2828     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2829     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2830     out for the ar command.)
2833 nigel 47 Version 3.2 12-May-00
2834     ---------------------
2836     This is purely a bug fixing release.
2838     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2839     of ZA. This was just one example of several cases that could provoke this bug,
2840     which was introduced by change 9 of version 2.00. The code for breaking
2841     infinite loops after an iteration that matches an empty string was't working
2842     correctly.
2844     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2845     when matched against abbab (for example). After matching an empty string, it
2846     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2847     caused it to match further down the string than it should.
2849     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2850     was there because it doesn't seem to be needed, and it causes trouble on some
2851     systems, as it is not a Standard C header. It has been removed.
2853     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2854     were reported on the Macintosh. The changes were from
2856     while ((c = *(++ptr)) != 0 && c != '\n');
2857     to
2858     while ((c = *(++ptr)) != 0 && c != '\n') ;
2860     Totally extraordinary, but if that's what it takes...
2862     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2863     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2864     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2865     assumes the way PCRE uses memmove() (always moving upwards).
2867     6. PCRE is being used in one environment where strchr() is not available. There
2868     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2869     faster code anyway.
2872 nigel 45 Version 3.1 09-Feb-00
2873     ---------------------
2875     The only change in this release is the fixing of some bugs in Makefile.in for
2876     the "install" target:
2878     (1) It was failing to install pcreposix.h.
2880     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2883 nigel 43 Version 3.0 01-Feb-00
2884     ---------------------
2885 nigel 41
2886     1. Add support for the /+ modifier to perltest (to output $` like it does in
2887     pcretest).
2889     2. Add support for the /g modifier to perltest.
2891     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2892     matches null strings.
2894     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2895     pattern. Perl treats empty patterns specially - it reuses the most recent
2896     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2897     effect.
2899     5. The POSIX interface was broken in that it was just handing over the POSIX
2900     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2901     required a bigger vector, with some working space on the end. This means that
2902     the POSIX wrapper now has to get and free some memory, and copy the results.
2904 nigel 43 6. Added some simple autoconf support, placing the test data and the
2905     documentation in separate directories, re-organizing some of the
2906     information files, and making it build pcre-config (a GNU standard). Also added
2907     libtool support for building PCRE as a shared library, which is now the
2908     default.
2909 nigel 41
2910 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2911     09 are not valid octal constants. Single digits will be used for minor values
2912     less than 10.
2914     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2915     existing programs that set these in the POSIX interface can use PCRE without
2916     modification.
2918     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2919     return all that pcre_info() returns, plus additional data. The pcre_info()
2920     function is retained for compatibility, but is considered to be obsolete.
2922     10. Added experimental recursion feature (?R) to handle one common case that
2923     Perl 5.6 will be able to do with (?p{...}).
2925     11. Added support for POSIX character classes like [:alpha:], which Perl is
2926     adopting.
2929 nigel 39 Version 2.08 31-Aug-99
2930     ----------------------
2932     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2933     trying to match at the startoffset position, but instead was moving forward to
2934     the next newline as if a previous match had failed.
2936     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2937     and could get into a loop if a null string was matched other than at the start
2938     of the subject.
2940     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2941     be distinguished at compile time, and for completeness also added PCRE_DATE.
2943     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2944     in GnuWin32 environments.
2947 nigel 37 Version 2.07 29-Jul-99
2948     ----------------------
2950     1. The documentation is now supplied in plain text form and HTML as well as in
2951     the form of man page sources.
2953     2. C++ compilers don't like assigning (void *) values to other pointer types.
2954     In particular this affects malloc(). Although there is no problem in Standard
2955     C, I've put in casts to keep C++ compilers happy.
2957     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2958     should be (const char *).
2960     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2961     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2962     However, I haven't made this a standard facility. The documentation doesn't
2963     mention it, and the Makefile doesn't support it.
2965     5. The Makefile now contains an "install" target, with editable destinations at
2966     the top of the file. The pcretest program is not installed.
2968     6. pgrep -V now gives the PCRE version number and date.
2970     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2971     causing the entire string to be ignored, instead of just the last character.
2973     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2974     non-matching string, it can take a very, very long time, even for strings of
2975     quite modest length, because of the nested recursion. PCRE now does better in
2976     some of these cases. It does this by remembering the last required literal
2977     character in the pattern, and pre-searching the subject to ensure it is present
2978     before running the real match. In other words, it applies a heuristic to detect
2979     some types of certain failure quickly, and in the above example, if presented
2980     with a string that has no trailing " it gives "no match" very quickly.
2982     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2983     other alternatives are tried instead.
2986 nigel 35 Version 2.06 09-Jun-99
2987     ----------------------
2989     1. Change pcretest's output for amount of store used to show just the code
2990     space, because the remainder (the data block) varies in size between 32-bit and
2991     64-bit systems.
2993     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2994     start matching at. This allows lookbehinds to work when searching for multiple
2995     occurrences in a string.
2997     3. Added additional options to pcretest for testing multiple occurrences:
2999     /+ outputs the rest of the string that follows a match
3000     /g loops for multiple occurrences, using the new startoffset argument
3001     /G loops for multiple occurrences by passing an incremented pointer
3003     4. PCRE wasn't doing the "first character" optimization for patterns starting
3004     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3005     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3006     the letter 'x'. On long subject strings, this gives a significant speed-up.
3009 nigel 33 Version 2.05 21-Apr-99
3010     ----------------------
3012     1. Changed the type of magic_number from int to long int so that it works
3013     properly on 16-bit systems.
3015     2. Fixed a bug which caused patterns starting with .* not to work correctly
3016     when the subject string contained newline characters. PCRE was assuming
3017     anchoring for such patterns in all cases, which is not correct because .* will
3018     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3019     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3020     must be retried after every newline in the subject.
3023 nigel 31 Version 2.04 18-Feb-99
3024     ----------------------
3026     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3027     computation of the store needed to hold the pattern was incorrect (too large).
3028     If such patterns were nested a few deep, this could multiply and become a real
3029     problem.
3031     2. Added /M option to pcretest to show the memory requirement of a specific
3032     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3034     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3035     compiled in such a way that the backtracking after subsequent failure was
3036     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3037     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3040 nigel 29 Version 2.03 02-Feb-99
3041     ----------------------
3043     1. Fixed typo and small mistake in man page.
3045 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3046     LICENCE file containing the conditions.
3047 nigel 29
3048     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3049     Perl, that is the internal \ allows the delimiter to be included in the
3050     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3051     the final delimiter, add \ to the end of the pattern (to test the error).
3053     4. Added the convenience functions for extracting substrings after a successful
3054     match. Updated pcretest to make it able to test these functions.
3057 nigel 27 Version 2.02 14-Jan-99
3058     ----------------------
3060     1. Initialized the working variables associated with each extraction so that
3061     their saving and restoring doesn't refer to uninitialized store.
3063     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3064     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3065     fix the problem.
3067     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3068     calls, and wasn't printing the correct value for compiling calls. Increased the
3069     default value of LOOPREPEAT, and the number of significant figures in the
3070     times.
3072     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3074     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3075     a building problem on Windows NT with a FAT file system.
3078 nigel 25 Version 2.01 21-Oct-98
3079     ----------------------
3081     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3082     to character tables built by pcre_maketables() in the current locale. If NULL
3083     is passed, the default tables are used.
3086 nigel 23 Version 2.00 24-Sep-98
3087 nigel 21 ----------------------
3089 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3090     it any more.
3092     2. Allow quantification of (?>) groups, and make it work correctly.
3094     3. The first character computation wasn't working for (?>) groups.
3096     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3097     end of the subject) and add 5.005's \z, which really does match only at the
3098     very end of the subject.
3100     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3102     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3103     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3104     localized options. All options to pcre_study() were also removed.
3106     7. Add other new features from 5.005:
3108     $(?<= positive lookbehind
3109     $(?<! negative lookbehind
3110     (?imsx-imsx) added the unsetting capability
3111     such a setting is global if at outer level; local otherwise
3112     (?imsx-imsx:) non-capturing groups with option setting
3113     (?(cond)re|re) conditional pattern matching
3115     A backreference to itself in a repeated group matches the previous
3116     captured string.
3118     8. General tidying up of studying (both automatic and via "study")
3119     consequential on the addition of new assertions.
3121     9. As in 5.005, unlimited repeated groups that could match an empty substring
3122     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3123     runtime if any iteration does actually match an empty substring.
3125     10. Include the RunTest script in the distribution.
3127     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3128     discrepancies, some of which were old and were also with respect to 5.004. They
3129     have now been fixed.
3132     Version 1.09 28-Apr-98
3133     ----------------------
3135 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3136     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3137     program crashes, or just wrong answers. This did not apply to negated classes
3138     containing more than one character, or to minima other than one.
3141 nigel 19 Version 1.08 27-Mar-98
3142     ----------------------
3144     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3146     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3147     latter must appear before anything that relies on it in the pattern.
3150 nigel 17 Version 1.07 16-Feb-98
3151     ----------------------
3153     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3154     repeat of a potentially empty string).
3157 nigel 15 Version 1.06 23-Jan-98
3158     ----------------------
3160     1. Added Markus Oberhumer's little patches for C++.
3162     2. Literal strings longer than 255 characters were broken.
3165 nigel 13 Version 1.05 23-Dec-97
3166     ----------------------
3168     1. Negated character classes containing more than one character were failing if
3169     PCRE_CASELESS was set at run time.
3172 nigel 11 Version 1.04 19-Dec-97
3173     ----------------------
3175     1. Corrected the man page, where some "const" qualifiers had been omitted.
3177     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3178     input syntax.
3180     3. Fixed memory leak which occurred when a regex with back references was
3181     matched with an offsets vector that wasn't big enough. The temporary memory
3182     that is used in this case wasn't being freed if the match failed.
3184     4. Tidied pcretest to ensure it frees memory that it gets.
3186     5. Temporary memory was being obtained in the case where the passed offsets
3187     vector was exactly big enough.
3189     6. Corrected definition of offsetof() from change 5 below.
3191     7. I had screwed up change 6 below and broken the rules for the use of
3192     setjmp(). Now fixed.
3195 nigel 9 Version 1.03 18-Dec-97
3196     ----------------------
3198     1. A erroneous regex with a missing opening parenthesis was correctly
3199     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3200     on some systems.
3202     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3203     it was reported that one broken compiler failed on the former because "code" is
3204     also an independent variable.
3206     3. The erroneous regex a[]b caused an array overrun reference.
3208     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3209     fail on data ending with that character. (It was going on too far, and checking
3210     the next character, typically a binary zero.) This was specific to the
3211     optimized code for single-character negative classes.
3213     5. Added a contributed patch from the TIN world which does the following:
3215     + Add an undef for memmove, in case the the system defines a macro for it.
3217     + Add a definition of offsetof(), in case there isn't one. (I don't know
3218     the reason behind this - offsetof() is part of the ANSI standard - but
3219     it does no harm).
3221     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3222     most of the places where whitespace preceded '#'. I have given up and
3223     allowed the remaining 2 cases to be at the margin.
3225     + Rename some variables in pcre to eliminate shadowing. This seems very
3226     pedantic, but does no harm, of course.
3228     6. Moved the call to setjmp() into its own function, to get rid of warnings
3229     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3231     7. Constructs such as \d{8,} were compiling into the equivalent of
3232 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3233 nigel 9 outcome, but in this particular case used more store than had been allocated,
3234     which caused the bug to be discovered because it threw up an internal error.
3236     8. The debugging code in both pcre and pcretest for outputting the compiled
3237     form of a regex was going wrong in the case of back references followed by
3238     curly-bracketed repeats.
3241 nigel 7 Version 1.02 12-Dec-97
3242     ----------------------
3244     1. Typos in pcre.3 and comments in the source fixed.
3246     2. Applied a contributed patch to get rid of places where it used to remove
3247     'const' from variables, and fixed some signed/unsigned and uninitialized
3248     variable warnings.
3250     3. Added the "runtest" target to Makefile.
3252     4. Set default compiler flag to -O2 rather than just -O.
3255 nigel 5 Version 1.01 19-Nov-97
3256     ----------------------
3258     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3259     like /([ab]*)*/, that is, for classes with more than one character in them.
3261     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3262     as /((?>a*))*/ (a PCRE_EXTRA facility).
3265     Version 1.00 18-Nov-97
3266     ----------------------
3268     1. Added compile-time macros to support systems such as SunOS4 which don't have
3269     memmove() or strerror() but have other things that can be used instead.
3271     2. Arranged that "make clean" removes the executables.
3274 nigel 3 Version 0.99 27-Oct-97
3275     ----------------------
3277     1. Fixed bug in code for optimizing classes with only one character. It was
3278     initializing a 32-byte map regardless, which could cause it to run off the end
3279     of the memory it had got.
3281     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3284     Version 0.98 22-Oct-97
3285     ----------------------
3287     1. Fixed bug in code for handling temporary memory usage when there are more
3288     back references than supplied space in the ovector. This could cause segfaults.
3291     Version 0.97 21-Oct-97
3292     ----------------------
3294     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3296     2. Optimized negated single characters not to use a bit map.
3298     3. Brought error texts together as macro definitions; clarified some of them;
3299     fixed one that was wrong - it said "range out of order" when it meant "invalid
3300     escape sequence".
3302     4. Changed some char * arguments to const char *.
3304     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3306     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3307     pcretest.
3310     Version 0.96 16-Oct-97
3311     ----------------------
3313     1. Added a simple "pgrep" utility to the distribution.
3315     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3316     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3317     where "ddd" means "one or more decimal digits".
3319     3. Fixed serious bug. If a pattern had a back reference, but the call to
3320     pcre_exec() didn't supply a large enough ovector to record the related
3321     identifying subpattern, the match always failed. PCRE now remembers the number
3322     of the largest back reference, and gets some temporary memory in which to save
3323     the offsets during matching if necessary, in order to ensure that
3324     backreferences always work.
3326     4. Increased the compatibility with Perl in a number of ways:
3328     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3329     to request this handling. The option can be set at compile or exec time.
3331     (b) $ matches before a terminating newline by default; an option
3332     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3333     mode). The option can be set at compile or exec time.
3335     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3336     the same as Perl's. If the decimal number it represents is less than 10
3337     or there aren't that many previous left capturing parentheses, an octal
3338     escape is read. Inside a character class, it's always an octal escape,
3339     even if it is a single digit.
3341     (d) An escaped but undefined alphabetic character is taken as a literal,
3342     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3343     escapes.
3345     (e) {0} is now permitted. (The previous item is removed from the compiled
3346     pattern).
3348     5. Changed all the names of code files so that the basic parts are no longer
3349     than 10 characters, and abolished the teeny "globals.c" file.
3351     6. Changed the handling of character classes; they are now done with a 32-byte
3352     bit map always.
3354     7. Added the -d and /D options to pcretest to make it possible to look at the
3355     internals of compilation without having to recompile pcre.
3358     Version 0.95 23-Sep-97
3359     ----------------------
3361     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3362     \x20 at the start of a run of normal characters. These were being treated as
3363     real characters, instead of the source characters being re-checked.
3366     Version 0.94 18-Sep-97
3367     ----------------------
3369     1. The functions are now thread-safe, with the caveat that the global variables
3370     containing pointers to malloc() and free() or alternative functions are the
3371     same for all threads.
3373     2. Get pcre_study() to generate a bitmap of initial characters for non-
3374     anchored patterns when this is possible, and use it if passed to pcre_exec().
3377     Version 0.93 15-Sep-97
3378     ----------------------
3380     1. /(b)|(:+)/ was computing an incorrect first character.
3382     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3383     but not actually doing anything yet.
3385     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3386     as Perl does (e.g. [-az] or [az-]).
3388     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3389     all possible positions.
3391     5. Split up into different modules to avoid including unneeded functions in a
3392     compiled binary. However, compile and exec are still in one module. The "study"
3393     function is split off.
3395     6. The character tables are now in a separate module whose source is generated
3396     by an auxiliary program - but can then be edited by hand if required. There are
3397     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3398     toupper() in the code.
3400     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3401     make them global. Abolish the function for setting them, as the caller can now
3402     set them directly.
3405     Version 0.92 11-Sep-97
3406     ----------------------
3408     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3409     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3411     2. Caseless matching was not working in character classes if the characters in
3412     the pattern were in upper case.
3414     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3416     4. Make PCRE_ANCHORED public and accept as a compile option.
3418     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3419     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3420     pass them.
3422     6. Give an error if bad option bits passed at compile or run time.
3424     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3425     pcretest to cause it to pass that flag.
3427     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3428     options, and the first character, if set.
3430     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3433     Version 0.91 10-Sep-97
3434     ----------------------
3436     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3437     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3439     2. PCRE was looping on encountering an indefinitely repeated back reference to
3440     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3441     Perl does - treats the match as successful.
3443     ****


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