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Revision 377 - (hide annotations) (download)
Sun Mar 1 12:07:19 2009 UTC (6 years, 1 month ago) by ph10
File size: 161070 byte(s)
Use colour when requested with -o in pcregrep.

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     5. When --colour was used with -o, the list of matching strings was not
28     coloured; this is different to GNU grep, so I have changed it to be the
29     same.
30 ph10 376
32 ph10 374 Version 7.8 05-Sep-08
33 ph10 349 ---------------------
35     1. Replaced UCP searching code with optimized version as implemented for Ad
36     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
37 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
38     to 5 times on some simple patterns that I tested. Permission was given to
39     distribute the MultiStage2.py script that generates the tables (it's not in
40     the tarball, but is in the Subversion repository).
41 ph10 349
42 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
43     scripts.
44 ph10 358
45 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
46     a group with a zero qualifier. The result of the study could be incorrect,
47 ph10 358 or the function might crash, depending on the pattern.
49     4. Caseless matching was not working for non-ASCII characters in back
50 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
51 ph10 358 It now works when Unicode Property Support is available.
53 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
54     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
55     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
56 ph10 358 truncation.
57 ph10 349
58 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
60 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
61     pointers, in case they are 64-bit values.
62 ph10 371
63     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
64     test 2 if it fails.
66 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
67 ph10 371 and a #define of that name to empty if it is not externally set. This is to
68     allow users of MSVC to set it if necessary.
70     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
71 ph10 359 the convenience functions in the pcre_get.c source file.
72 ph10 371
73 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
74     could cause overwriting and/or a crash. This command provoked a crash in
75 ph10 371 some environments:
77     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
79 ph10 360 This potential security problem was recorded as CVE-2008-2371.
80 ph10 371
81 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
82     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
83 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
84 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
85     pcretest so that it places the subject at the end of its malloc-ed buffer.
86 ph10 371
87 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
88 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
90 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
91 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
92     first line. This applied both to normal and DFA matching.
94 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
95 ph10 371 /^[^d]*?$/8 failed to match "abc".
96 ph10 351
97 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
99     17. Make it more clear in the documentation that values returned from
100 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
101 ph10 357
102 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
103 ph10 368
104 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
105     supplied by Stefan Weber. I made a further small update for 7.8 because
106 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
107     replaced by pcre_ucd.c.
108 ph10 371
109 ph10 373
110 ph10 347 Version 7.7 07-May-08
111 ph10 321 ---------------------
113     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
114 ph10 345 a string to a long long, pretend we don't even have a long long." This is
115 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
116 ph10 345
117 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
118     pre-7.6 versions, which defined a global no_arg variable instead of putting
119 ph10 332 it in the RE class. (See also #8 below.)
120 ph10 345
121     3. Remove a line of dead code, identified by coverity and reported by Nuno
122     Lopes.
124 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
125 ph10 321
126 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
127 ph10 345 of files, instead of just to the final components.
129 ph10 324 (2) If there was more than one level of directory, the subdirectories were
130     skipped unless they satisfied the include/exclude conditions. This is
131     inconsistent with GNU grep (and could even be seen as contrary to the
132     pcregrep specification - which I improved to make it absolutely clear).
133     The action now is always to scan all levels of directory, and just
134     apply the include/exclude patterns to regular files.
135 ph10 345
136 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
137 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
139 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
140 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
141 ph10 326 doesn't support NULs in patterns.
142 ph10 345
143     7. Added some missing "const"s to declarations of static tables in
144     pcre_compile.c and pcre_dfa_exec.c.
146 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
147 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
148 ph10 345 first patch. And a third patch - this was a messy problem.)
149 ph10 321
150 ph10 345 9. Applied Craig's patch to remove the use of push_back().
152 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
153     matching function regexec().
154 ph10 345
155     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
156     which, however, unlike Perl's \g{...}, are subroutine calls, not back
157 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
158     Oniguruma does).
159 ph10 345
160     12. Previously, a group with a zero repeat such as (...){0} was completely
161 ph10 335 omitted from the compiled regex. However, this means that if the group
162     was called as a subroutine from elsewhere in the pattern, things went wrong
163 ph10 345 (an internal error was given). Such groups are now left in the compiled
164     pattern, with a new opcode that causes them to be skipped at execution
165 ph10 335 time.
166 ph10 345
167 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
168     to the way PCRE behaves:
169 ph10 345
170 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
171 ph10 345
172     (b) A back reference to an unmatched subpattern matches an empty string
173 ph10 336 (Perl fails the current match path).
174 ph10 345
175 ph10 341 (c) A data ] in a character class must be notated as \] because if the
176 ph10 345 first data character in a class is ], it defines an empty class. (In
177 ph10 341 Perl it is not possible to have an empty class.) The empty class []
178     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
179     The negative empty class [^] matches any one character, independently
180     of the DOTALL setting.
181 ph10 345
182     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
183 ph10 340 non-existent subpattern following a character class starting with ']' and
184     containing () gave an internal compiling error instead of "reference to
185     non-existent subpattern". Fortunately, when the pattern did exist, the
186 ph10 345 compiled code was correct. (When scanning forwards to check for the
187 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
188 ph10 345 the class, so got the count wrong. When actually compiling, the reference
189 ph10 340 was subsequently set up correctly.)
190 ph10 345
191 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
192 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
193     other assertions are supported. I have made pcre_dfa_exec() support
194     (*FAIL).
196 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
197 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
198     cannot be changed at match time, I realized I could make a small
199     improvement to matching performance by compiling OP_ALLANY instead of
200     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
201     on the OP_ANY path.
203     17. Compiling pcretest on Windows with readline support failed without the
204 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
205 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
207 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
208 ph10 345 ncurses library to be included for pcretest when ReadLine support is
209     requested, but also to allow for it to be overridden. This patch came from
210     Daniel Bergström.
211 ph10 347
212 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
213 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
214     any errors with the current Unicode tables. Thanks to Peter Kankowski for
215     spotting this.
216 ph10 324
217 ph10 332
218 ph10 319 Version 7.6 28-Jan-08
219 ph10 300 ---------------------
221 ph10 302 1. A character class containing a very large number of characters with
222     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
223     overflow.
224 ph10 309
225     2. Patch to cut out the "long long" test in pcrecpp_unittest when
226     HAVE_LONG_LONG is not defined.
228 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
229 ph10 304 bring them up to date and include new features. This patch includes:
230 ph10 309
231 ph10 304 - Fixed PH's badly added libz and libbz2 support.
232     - Fixed a problem with static linking.
233 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
234 ph10 304 - Fixed dftables problem and added an option.
235     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
237     - Added readline support for pcretest.
238 ph10 309 - Added an listing of the option settings after cmake has run.
240 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
241     "pcre.dll" under mingw when using Configure/Make. I added stuff to
242     Makefile.am that cause it to include this special target, without
243     affecting anything else. Note that the same mingw target plus all
244     the other distribution libraries and programs are now supported
245     when configuring with CMake (see 6 below) instead of with
246     Configure/Make.
247 ph10 309
248 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
249     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
250 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
251     solves the problem, but it does no harm.
252 ph10 313
253 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
254 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
255 ph10 314 with CMake, and also correct the comment about stack recursion.
256 ph10 313
257 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
258 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
259     of a program that users should build themselves after PCRE is installed, so
260     building it automatically is not really right. What is more, it gave
261 ph10 312 trouble in some build environments.
262 ph10 300
263 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
264 ph10 308
265 ph10 319
266 ph10 298 Version 7.5 10-Jan-08
267 ph10 263 ---------------------
269     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
270     values in parens when parsing an RE using the C++ wrapper."
271 ph10 286
272 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
273     Characters greater than 255 were excluded from the class instead of being
274     included.
275 ph10 286
276     3. The same bug as (2) above applied to negated POSIX classes such as
277 ph10 265 [:^space:].
278 ph10 286
279 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
280     defined or documented. It seems to have been a typo for PCRE_STATIC, so
281 ph10 286 I have changed it.
283 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
284 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
285     first named subpattern whose name started with "a" (in other words, the
286 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
287     expected" is now given for (?&) (a zero-length name), and this patch also
288     makes it give the same error for \k'' (previously it complained that that
289     was a reference to a non-existent subpattern).
290 ph10 286
291 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
292 ph10 286 this is right because (?- can be followed by option settings as well as by
293 ph10 269 digits. I have, however, made the messages clearer.
294 ph10 286
295 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
296     than the number used in the conditional) now cause a compile-time error.
297     This is actually not compatible with Perl, which accepts such patterns, but
298     treats the conditional as always being FALSE (as PCRE used to), but it
299     seems to me that giving a diagnostic is better.
300 ph10 286
301 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
302 ph10 275 and messages.
303 ph10 286
304     9. Fix two occurrences of "backslash" in comments that should have been
305     "backspace".
307     10. Remove two redundant lines of code that can never be obeyed (their function
308     was moved elsewhere).
310     11. The program that makes PCRE's Unicode character property table had a bug
311     which caused it to generate incorrect table entries for sequences of
312 ph10 277 characters that have the same character type, but are in different scripts.
313 ph10 286 It amalgamated them into a single range, with the script of the first of
314 ph10 277 them. In other words, some characters were in the wrong script. There were
315     thirteen such cases, affecting characters in the following ranges:
316 ph10 286
317 ph10 277 U+002b0 - U+002c1
318     U+0060c - U+0060d
319 ph10 286 U+0061e - U+00612
320 ph10 277 U+0064b - U+0065e
321     U+0074d - U+0076d
322     U+01800 - U+01805
323     U+01d00 - U+01d77
324     U+01d9b - U+01dbf
325     U+0200b - U+0200f
326     U+030fc - U+030fe
327     U+03260 - U+0327f
328     U+0fb46 - U+0fbb1
329     U+10450 - U+1049d
330 ph10 286
331 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
332     compatible with GNU grep in that, if there was more than one match in a
333     line, it showed only the first of them. It now behaves in the same way as
334     GNU grep.
335 ph10 286
336     13. If the -o and -v options were combined for pcregrep, it printed a blank
337     line for every non-matching line. GNU grep prints nothing, and pcregrep now
338     does the same. The return code can be used to tell if there were any
339     non-matching lines.
341 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
343     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
344 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
345 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
346     and both kinds of lookbehind were skipped).
348 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
349 ph10 284 inclusion of <windows.h> to before rather than after the definition of
350     INVALID_FILE_ATTRIBUTES (patch from David Byron).
351 ph10 263
352 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
353 ph10 286 character property caused pcre_compile() to compile bad code, which led at
354     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
355     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
356     caused the error; without that there was no problem.
357 ph10 263
358 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
359 ph10 286
360 ph10 289 19. Added --enable-pcretest-libreadline.
361 ph10 286
362 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
363 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
364 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
365     later patch that removed the other one (the right fix) and added unit tests
366     that check the return values (which was not done before).
367 ph10 292
368 ph10 291 21. Several CMake things:
369 ph10 287
370 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
371 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
372 ph10 288
373 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
374     linked with the newly-built libraries, not previously installed ones.
375 ph10 291
377 ph10 298
378     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
379     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
380     UTF-8 newline character). The key issue is that the pattern starts .*;
381     this means that the match must be either at the beginning, or after a
382     newline. The bug was in the code for advancing after a failed match and
383     checking that the new position followed a newline. It was not taking
384 ph10 294 account of UTF-8 characters correctly.
385 ph10 298
386     23. PCRE was behaving differently from Perl in the way it recognized POSIX
387     character classes. PCRE was not treating the sequence [:...:] as a
388     character class unless the ... were all letters. Perl, however, seems to
389     allow any characters between [: and :], though of course it rejects as
390     unknown any "names" that contain non-letters, because all the known class
391     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
392     for example, whereas PCRE did not - it did not recognize a POSIX character
393     class. This seemed a bit dangerous, so the code has been changed to be
394     closer to Perl. The behaviour is not identical to Perl, because PCRE will
395     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
396     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
397     Perl does, and where it didn't before.
399 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
400     Windows environments %n is disabled by default.
401 ph10 292
403 ph10 260 Version 7.4 21-Sep-07
404 ph10 230 ---------------------
406     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
407 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
408     LF". That isn't really right - the whole point of the change was to try to
409     help when there was an actual mention of one of the two characters. So now
410     the change happens only if \r or \n (or a literal CR or LF) character is
411 ph10 230 encountered.
412 ph10 231
413     2. The 32-bit options word was also used for 6 internal flags, but the numbers
414     of both had grown to the point where there were only 3 bits left.
415     Fortunately, there was spare space in the data structure, and so I have
416     moved the internal flags into a new 16-bit field to free up more option
417 ph10 230 bits.
418 ph10 231
419     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
420     but did not set the internal JCHANGED flag - either of these is enough to
421     control the way the "get" function works - but the PCRE_INFO_JCHANGED
422     facility is supposed to tell if (?J) was ever used, so now (?J) at the
423 ph10 230 start sets both bits.
425 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
426     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
427 ph10 230
428 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
430     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
431 ph10 233 compatibility, even though it is no longer used.
432 ph10 243
433     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
434 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
435 ph10 259 windows.h file is present (where different names are used). [This was
436 ph10 257 reversed later after testing - see 16 below.]
437 ph10 243
438     8. Changed all #include <config.h> to #include "config.h". There were also
439 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
440 ph10 243
441 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
442 ph10 243 sequence off the lines that it output.
444     10. It was pointed out to me that arrays of string pointers cause lots of
445     relocations when a shared library is dynamically loaded. A technique of
446     using a single long string with a table of offsets can drastically reduce
447     these. I have refactored PCRE in four places to do this. The result is
448 ph10 240 dramatic:
449 ph10 243
450 ph10 240 Originally: 290
451     After changing UCP table: 187
452 ph10 243 After changing error message table: 43
453 ph10 240 After changing table of "verbs" 36
454     After changing table of Posix names 22
455 ph10 243
456 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
457 ph10 247
458 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
459 ph10 247 unicode-properties was also set.
461 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
462 ph10 231
463 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
464     checked only for CRLF.
465 ph10 233
466 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
468 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
469 ph10 253
470 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
471 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
472     entirely. This removes changes made in 7 above.
473 ph10 256
474 ph10 261 17. The CMake files have been updated, and there is now more information about
475     building with CMake in the NON-UNIX-USE document.
476 ph10 257
477 ph10 261
478 ph10 228 Version 7.3 28-Aug-07
479 ph10 157 ---------------------
481 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
482     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
483     brackets there is not right, since it causes compilers to look for an
484     installed pcre.h, not the version that is in the source that is being
485     compiled (which of course may be different). I have changed it back to:
486 ph10 197
487 ph10 189 #include "pcre.h"
488 ph10 197
489     I have a vague recollection that the change was concerned with compiling in
490     different directories, but in the new build system, that is taken care of
491     by the VPATH setting the Makefile.
493 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
494     when the subject happened to end in the byte 0x85 (e.g. if the last
495     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
496     characters but of course it shouldn't be taken as a newline when it is part
497     of another character. The bug was that, for an unlimited repeat of . in
498     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
499     characters when looking for a newline.
500 ph10 197
501     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
503     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
504     in debug output.
506 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
507     long printing in the pcrecpp unittest when running under MinGW.
508 ph10 189
509 ph10 197 6. ESC_K was left out of the EBCDIC table.
510 ph10 189
511 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
512     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
513     limit also applies to "virtual nesting" when a pattern is recursive, and in
514     this case 1000 isn't so big. I have been able to remove this limit at the
515     expense of backing off one optimization in certain circumstances. Normally,
516     when pcre_exec() would call its internal match() function recursively and
517     immediately return the result unconditionally, it uses a "tail recursion"
518     feature to save stack. However, when a subpattern that can match an empty
519     string has an unlimited repetition quantifier, it no longer makes this
520     optimization. That gives it a stack frame in which to save the data for
521     checking that an empty string has been matched. Previously this was taken
522     from the 1000-entry workspace that had been reserved. So now there is no
523     explicit limit, but more stack is used.
524 ph10 189
525 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
526     syntax that is required for Windows, and which was going wrong for the
527     pcreposix and pcrecpp parts of the library. These were overlooked when this
528     problem was solved for the main library.
529 ph10 197
530 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
531     the size of patterns that contain repeated groups with explicit upper
532     limits. As the maximum quantifier is 65535, the maximum group length was
533     set at 30,000 so that the product of these two numbers did not overflow a
534     32-bit integer. However, it turns out that people want to use groups that
535     are longer than 30,000 bytes (though not repeat them that many times).
536     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
537     made it possible to implement the integer overflow checks in a much more
538     dynamic way, which I have now done. The artificial limitation on group
539     length has been removed - we now have only the limit on the total length of
540     the compiled pattern, which depends on the LINK_SIZE setting.
541 ph10 208
542     10. Fixed a bug in the documentation for get/copy named substring when
543     duplicate names are permitted. If none of the named substrings are set, the
544     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
545     empty string.
547     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
548     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
549     because the ] is interpreted as the first data character and the
550     terminating ] is not found. PCRE has been made compatible with Perl in this
551     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
552     cause memory overwriting.
554 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
555     string has been matched (to stop an infinite loop). It was not recognizing
556 ph10 208 a conditional subpattern that could match an empty string if that
557 ph10 206 subpattern was within another subpattern. For example, it looped when
558 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
559 ph10 206 condition was not nested. This bug has been fixed.
560 ph10 208
561 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
562     past the start of the subject in the presence of bytes with the top bit
563     set, for example "\x8aBCD".
564 ph10 211
565 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
566     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
567 ph10 200
568 ph10 211 14. Optimized (?!) to (*FAIL).
569 ph10 202
570 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
571     This restricts code points to be within the range 0 to 0x10FFFF, excluding
572     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
573     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
574     does: it's just the validity check that is more restrictive.
575 ph10 220
576     16. Inserted checks for integer overflows during escape sequence (backslash)
577     processing, and also fixed erroneous offset values for syntax errors during
578     backslash processing.
580 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
581 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
583 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
584     caused an overrun.
585 ph10 220
586     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
587     something other than just ASCII characters) inside a group that had an
588     unlimited repeat caused a loop at compile time (while checking to see
589     whether the group could match an empty string).
591 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
592     [\P{Any}] did so. (Error in the code for printing property names.)
593 ph10 210
594 ph10 220 21. An orphan \E inside a character class could cause a crash.
596     22. A repeated capturing bracket such as (A)? could cause a wild memory
597 ph10 218 reference during compilation.
598 ph10 220
599     23. There are several functions in pcre_compile() that scan along a compiled
600     expression for various reasons (e.g. to see if it's fixed length for look
601 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
602 ph10 220 present in the pattern. These operators have additional parameters compared
603     with \d, etc, and these were not being taken into account when moving along
604 ph10 218 the compiled data. Specifically:
605 ph10 220
606     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
607     length.
609     (b) An item such as \pL+ within a repeated group could cause crashes or
610 ph10 218 loops.
611 ph10 220
612 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
613 ph10 220 "reference to non-existent subpattern" error.
615 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
617 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
618 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
619 ph10 211
620 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
621 ph10 218
622 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
623 ph10 223 character were causing crashes (broken optimization).
624 ph10 227
625 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
626 ph10 227 \p or \P) caused a compile-time loop.
628 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
629     break. For example, the unstudied pattern [\r\n]A does not match the string
630     "\r\nA" because change 7.0/46 below moves the current point on by two
631     characters after failing to match at the start. However, the pattern \nA
632 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
633     the same is true. There doesn't seem any very clean way out of this, but
634     what I have chosen to do makes the common cases work: PCRE now takes note
635     of whether there can be an explicit match for \r or \n anywhere in the
636     pattern, and if so, 7.0/46 no longer applies. As part of this change,
637     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
638     pattern has explicit CR or LF references.
639 ph10 222
640 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
641 ph10 223
642 ph10 227
643 ph10 189 Version 7.2 19-Jun-07
644     ---------------------
646 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
647     which is apparently normally available under Windows.
648 ph10 159
649     2. Re-jig the pcregrep tests with different newline settings in an attempt
650     to make them independent of the local environment's newline setting.
651 ph10 157
652 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
653 ph10 165
654 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
655     was not 2, because the output contained actual offsets. The recent new
656 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
657     usable with all link sizes.
659 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
660     stack recursion. This gives a massive performance boost under BSD, but just
661 ph10 165 a small improvement under Linux. However, it saves one field in the frame
662 ph10 164 in all cases.
663 ph10 172
664 ph10 166 6. Added more features from the forthcoming Perl 5.10:
665 ph10 172
666 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
667     recursion call. It refers to the nth most recently opened parentheses.
668 ph10 172
669 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
670 ph10 172 to be opened parentheses.
672     (c) Conditions that refer to capturing parentheses can be specified
673 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
674 ph10 172
675 ph10 168 (d) \K resets the start of the current match so that everything before
676 ph10 172 is not part of it.
678 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
679 ph10 172
680 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
681 ph10 172 reference syntax.
682 ph10 182
683 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
684 ph10 182 alternative starts with the same number.
685 ph10 172
686 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
688 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
691     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
692     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
693 ph10 170 for detecting groups that can match an empty string.
694 ph10 159
695 ph10 172 9. A pattern with a very large number of alternatives (more than several
696     hundred) was running out of internal workspace during the pre-compile
697     phase, where pcre_compile() figures out how much memory will be needed. A
698     bit of new cunning has reduced the workspace needed for groups with
699     alternatives. The 1000-alternative test pattern now uses 12 bytes of
700     workspace instead of running out of the 4096 that are available.
701 ph10 182
702 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
703 ph10 172
704 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
705     The report of the bug said:
706 ph10 182
707 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
708     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
709 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
710 ph10 185
711 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
712 ph10 185 it matched the wrong number of bytes.
713 ph10 172
714 ph10 179
715 ph10 155 Version 7.1 24-Apr-07
716 ph10 98 ---------------------
718 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
719 ph10 122 that is more "standard", making use of automake and other Autotools. There
720 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
721     on this.
722 ph10 111
723     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
724     for recursive directory scanning broke on some systems because the files
725     are not scanned in any specific order and on different systems the order
726     was different. A call to "sort" has been inserted into RunGrepTest for the
727     approprate test as a short-term fix. In the longer term there may be an
728 ph10 100 alternative.
729 ph10 111
730 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
731 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
732     people do their own conversions for various reasons). The problems
733     concerned the use of low-level troff macros .br and .in. I have therefore
734     removed all such uses from the man pages (some were redundant, some could
735 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
736     HTML has been updated to handle .nf/.fi and to complain if it encounters
737     .br or .in.
738 ph10 111
739 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
740 ph10 123 arranged for config.h to be included in the distribution, with the name
741 ph10 111 config.h.generic, for the benefit of those who have to compile without
742     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
744     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
745     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
746 ph10 127 makevp.bat for the current PCRE, using the additional files
747 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
748 ph10 111
749     6. A Windows user reported a minor discrepancy with test 2, which turned out
750     to be caused by a trailing space on an input line that had got lost in his
751 ph10 102 copy. The trailing space was an accident, so I've just removed it.
752 ph10 111
753 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
754 ph10 111 that is needed.
756 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
757     as "const" (a) because they are and (b) because it helps the PHP
758     maintainers who have recently made a script to detect big data structures
759 ph10 111 in the php code that should be moved to the .rodata section. I remembered
760     to update Builducptable as well, so it won't revert if ucptable.h is ever
761 ph10 105 re-created.
762 ph10 111
763     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
764 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
765 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
766     support is not required. This saves 1.5-2K of code, which is important in
767 ph10 107 some applications.
768 ph10 111
769 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
770 ph10 111 so as not to refer to the tables, even though these functions will never be
771     called when UTF-8 support is disabled. Otherwise there are problems with a
772     shared library.
774 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
776     (a) It was defining its arguments as char * instead of void *.
778 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
779     a long time ago when I wrote it, but is no longer the case.
781 ph10 118 The emulated memove() is provided for those environments that have neither
782 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
783 ph10 118 is clearly not the case, as these two bugs were recently reported.
784 ph10 123
785 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
786 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
787     pages, and it removes trailing spaces from listed files. It also creates
788     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
789     case, it wraps all the #defines with #ifndefs. This script should be run
790 ph10 111 before "make dist".
791 ph10 123
792 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
793     with Unicode property support.
794 ph10 123
795     (a) For a maximizing quantifier, if the two different cases of the
796     character were of different lengths in their UTF-8 codings (there are
797     some cases like this - I found 11), and the matching function had to
798 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
799     were both the same length.
800 ph10 123
801     (b) When PCRE was configured to use the heap rather than the stack for
802     recursion during matching, it was not correctly preserving the data for
803     the other case of a UTF-8 character when checking ahead for a match
804     while processing a minimizing repeat. If the check also involved
805 ph10 115 matching a wide character, but failed, corruption could cause an
806     erroneous result when trying to check for a repeat of the original
807     character.
808 ph10 123
809 ph10 116 13. Some tidying changes to the testing mechanism:
810 ph10 98
811 ph10 116 (a) The RunTest script now detects the internal link size and whether there
812     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
813 ph10 123 values substituted by "configure". (The RunGrepTest script already did
814     this for UTF-8.) The configure.ac script no longer substitutes the
815     relevant variables.
817 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
818     with length and offset values. This means that the output is different
819     for different internal link sizes. Test 2 is skipped for link sizes
820     other than 2 because of this, bypassing the problem. Unfortunately,
821     there was also a test in test 3 (the locale tests) that used /B and
822 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
823     I have added a new /Z option to pcretest that replaces the length and
824     offset values with spaces. This is now used to make test 3 independent
825 ph10 122 of link size. (Test 2 will be tidied up later.)
826 ph10 123
827     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
828 ph10 122 segmentation fault instead of returning the appropriate error message.
829 ph10 134
830 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
831 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
832     This doesn't seem right; it now treats the CRLF combination as the line
833     ending, and so does not match in that case. It's only a pattern such as ^$
834     that would hit this one: something like ^ABC$ would have failed after \r
835     and then tried again after \r\n.
837 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
838 ph10 134 in an attempt to make files that differ only in their line terminators
839     compare equal. This works on Linux.
840 ph10 142
841 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
842     as it exited. This is now fixed, thanks to valgrind.
843 ph10 142
844 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
845 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
846     was because its rules for how to advance for /g after matching an empty
847 ph10 143 string at the end of a line did not allow for this case. They now check for
848     it specially.
849 ph10 150
850     20. pcretest is supposed to handle patterns and data of any length, by
851     extending its buffers when necessary. It was getting this wrong when the
852 ph10 147 buffer for a data line had to be extended.
853 ph10 150
854 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
855 ph10 150 CRLF as a newline sequence.
856 ph10 152
857 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
858 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
859     I have nevertheless tidied it up.
860 ph10 111
861 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
862 ph10 123
863 ph10 153 24. Added a man page for pcre-config.
864 ph10 152
865 ph10 153
866 nigel 93 Version 7.0 19-Dec-06
867     ---------------------
869     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
870     moving to gcc 4.1.1.
872     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
873     sys/time.h, which is documented as needed for this function. It doesn't
874     seem to matter on Linux, but it showed up on some releases of OS X.
876     3. It seems that there are systems where bytes whose values are greater than
877     127 match isprint() in the "C" locale. The "C" locale should be the
878     default when a C program starts up. In most systems, only ASCII printing
879     characters match isprint(). This difference caused the output from pcretest
880     to vary, making some of the tests fail. I have changed pcretest so that:
882     (a) When it is outputting text in the compiled version of a pattern, bytes
883     other than 32-126 are always shown as hex escapes.
885     (b) When it is outputting text that is a matched part of a subject string,
886     it does the same, unless a different locale has been set for the match
887     (using the /L modifier). In this case, it uses isprint() to decide.
889     4. Fixed a major bug that caused incorrect computation of the amount of memory
890     required for a compiled pattern when options that changed within the
891     pattern affected the logic of the preliminary scan that determines the
892     length. The relevant options are -x, and -i in UTF-8 mode. The result was
893     that the computed length was too small. The symptoms of this bug were
894     either the PCRE error "internal error: code overflow" from pcre_compile(),
895     or a glibc crash with a message such as "pcretest: free(): invalid next
896     size (fast)". Examples of patterns that provoked this bug (shown in
897     pcretest format) are:
899     /(?-x: )/x
900     /(?x)(?-x: \s*#\s*)/
901     /((?i)[\x{c0}])/8
902     /(?i:[\x{c0}])/8
904     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
905     is now done differently.
907     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
908     wrapper classes; (b) implement a new function in the C++ scanner that is
909     more efficient than the old way of doing things because it avoids levels of
910     recursion in the regex matching; (c) add a paragraph to the documentation
911     for the FullMatch() function.
913     6. The escape sequence \n was being treated as whatever was defined as
914     "newline". Not only was this contrary to the documentation, which states
915     that \n is character 10 (hex 0A), but it also went horribly wrong when
916     "newline" was defined as CRLF. This has been fixed.
918     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
919     was being set to -1 for the "end of line" case (supposedly a value that no
920     character can have). Though this value is never used (the check for end of
921     line is "zero bytes in current character"), it caused compiler complaints.
922     I've changed it to 0xffffffff.
924     8. In pcre_version.c, the version string was being built by a sequence of
925     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
926     string (as it is for production releases) called a macro with an empty
927     argument. The C standard says the result of this is undefined. The gcc
928     compiler treats it as an empty string (which was what was wanted) but it is
929     reported that Visual C gives an error. The source has been hacked around to
930     avoid this problem.
932     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
933     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
934     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
935     of them did).
937     10. Originally, pcretest opened its input and output without "b"; then I was
938     told that "b" was needed in some environments, so it was added for release
939     5.0 to both the input and output. (It makes no difference on Unix-like
940     systems.) Later I was told that it is wrong for the input on Windows. I've
941     now abstracted the modes into two macros, to make it easier to fiddle with
942     them, and removed "b" from the input mode under Windows.
944     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
946     12. Added -help and --help to pcretest as an official way of being reminded
947     of the options.
949     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
950     and pcrecpp.cc because they annoy compilers at high warning levels.
952     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
954     15. Fixed an occurrence of == in configure.ac that should have been = (shell
955     scripts are not C programs :-) and which was not noticed because it works
956     on Linux.
958     16. pcretest is supposed to handle any length of pattern and data line (as one
959     line or as a continued sequence of lines) by extending its input buffer if
960     necessary. This feature was broken for very long pattern lines, leading to
961     a string of junk being passed to pcre_compile() if the pattern was longer
962     than about 50K.
964     17. I have done a major re-factoring of the way pcre_compile() computes the
965     amount of memory needed for a compiled pattern. Previously, there was code
966     that made a preliminary scan of the pattern in order to do this. That was
967     OK when PCRE was new, but as the facilities have expanded, it has become
968     harder and harder to keep it in step with the real compile phase, and there
969     have been a number of bugs (see for example, 4 above). I have now found a
970     cunning way of running the real compile function in a "fake" mode that
971     enables it to compute how much memory it would need, while actually only
972     ever using a few hundred bytes of working memory and without too many
973     tests of the mode. This should make future maintenance and development
974     easier. A side effect of this work is that the limit of 200 on the nesting
975     depth of parentheses has been removed (though this was never a serious
976     limitation, I suspect). However, there is a downside: pcre_compile() now
977     runs more slowly than before (30% or more, depending on the pattern). I
978     hope this isn't a big issue. There is no effect on runtime performance.
980     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
981     newline (only possible for the last line of a file) and it was a
982     pattern that set a locale (followed by /Lsomething), pcretest crashed.
984     19. Added additional timing features to pcretest. (1) The -tm option now times
985     matching only, not compiling. (2) Both -t and -tm can be followed, as a
986     separate command line item, by a number that specifies the number of
987     repeats to use when timing. The default is 50000; this gives better
988     precision, but takes uncomfortably long for very large patterns.
990     20. Extended pcre_study() to be more clever in cases where a branch of a
991     subpattern has no definite first character. For example, (a*|b*)[cd] would
992     previously give no result from pcre_study(). Now it recognizes that the
993     first character must be a, b, c, or d.
995     21. There was an incorrect error "recursive call could loop indefinitely" if
996     a subpattern (or the entire pattern) that was being tested for matching an
997     empty string contained only one non-empty item after a nested subpattern.
998     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
999     incorrectly, because the \d was being skipped in the check.
1001     22. The pcretest program now has a new pattern option /B and a command line
1002     option -b, which is equivalent to adding /B to every pattern. This causes
1003     it to show the compiled bytecode, without the additional information that
1004     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1005     is the same as /B/I).
1007     23. A new optimization is now able automatically to treat some sequences such
1008     as a*b as a*+b. More specifically, if something simple (such as a character
1009     or a simple class like \d) has an unlimited quantifier, and is followed by
1010     something that cannot possibly match the quantified thing, the quantifier
1011     is automatically "possessified".
1013     24. A recursive reference to a subpattern whose number was greater than 39
1014     went wrong under certain circumstances in UTF-8 mode. This bug could also
1015     have affected the operation of pcre_study().
1017     25. Realized that a little bit of performance could be had by replacing
1018     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1020     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1022     27. Possessive quantifiers such as a++ were previously implemented by turning
1023     them into atomic groups such as ($>a+). Now they have their own opcodes,
1024     which improves performance. This includes the automatically created ones
1025     from 23 above.
1027     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1028     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1029     the first matched character to be a colon. This applied both to named and
1030     numbered groups.
1032     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1034     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1035     building PCRE on Windows easier, so I have included it in the distribution.
1037     31. There is now a check in pcretest against a ridiculously large number being
1038     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1039     loop, the loop is abandoned.
1041     32. Forward references to subpatterns in conditions such as (?(2)...) where
1042     subpattern 2 is defined later cause pcre_compile() to search forwards in
1043     the pattern for the relevant set of parentheses. This search went wrong
1044     when there were unescaped parentheses in a character class, parentheses
1045     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1047     33. "Subroutine" calls and backreferences were previously restricted to
1048     referencing subpatterns earlier in the regex. This restriction has now
1049     been removed.
1051     34. Added a number of extra features that are going to be in Perl 5.10. On the
1052     whole, these are just syntactic alternatives for features that PCRE had
1053     previously implemented using the Python syntax or my own invention. The
1054     other formats are all retained for compatibility.
1056     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1057     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1058     also .NET compatible.
1060     (b) A recursion or subroutine call to a named group can now be defined as
1061     (?&name) as well as (?P>name).
1063     (c) A backreference to a named group can now be defined as \k<name> or
1064     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1065     5.10, are also .NET compatible.
1067     (d) A conditional reference to a named group can now use the syntax
1068     (?(<name>) or (?('name') as well as (?(name).
1070     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1071     groups (named and numbered) that are never evaluated inline, but can be
1072     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1073     is always false. There may be only one alternative in such a group.
1075     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1076     as the simple (?(R). The condition is true only if the most recent
1077     recursion is that of the given number or name. It does not search out
1078     through the entire recursion stack.
1080     (g) The escape \gN or \g{N} has been added, where N is a positive or
1081     negative number, specifying an absolute or relative reference.
1083     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1084     some "unreachable code" warnings.
1086     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1087     things, this adds five new scripts.
1089     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1090     There were also incompatibilities regarding the handling of \Q..\E inside
1091     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1092     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1094     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1095     matches an empty string, and forcibly breaks the loop. There were bugs in
1096     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1097     against aaaa the result was just "a" rather than "aaaa", for example. Two
1098     separate and independent bugs (that affected different cases) have been
1099     fixed.
1101     39. Refactored the code to abolish the use of different opcodes for small
1102     capturing bracket numbers. This is a tidy that I avoided doing when I
1103     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1104     The new approach is not only tidier, it makes it possible to reduce the
1105     memory needed to fix the previous bug (38).
1107     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1108     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1109     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1110     mode.
1112     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1113     report.
1115     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1116     copy construction and assignment in the C++ wrapper.
1118     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1119     couple of bugs that could have given wrong results in the "--newline=crlf"
1120     case.
1122     44. Added a number of casts and did some reorganization of signed/unsigned int
1123     variables following suggestions from Dair Grant. Also renamed the variable
1124     "this" as "item" because it is a C++ keyword.
1126     45. Arranged for dftables to add
1128     #include "pcre_internal.h"
1130     to pcre_chartables.c because without it, gcc 4.x may remove the array
1131     definition from the final binary if PCRE is built into a static library and
1132     dead code stripping is activated.
1134     46. For an unanchored pattern, if a match attempt fails at the start of a
1135     newline sequence, and the newline setting is CRLF or ANY, and the next two
1136     characters are CRLF, advance by two characters instead of one.
1139 nigel 91 Version 6.7 04-Jul-06
1140     ---------------------
1142     1. In order to handle tests when input lines are enormously long, pcretest has
1143     been re-factored so that it automatically extends its buffers when
1144     necessary. The code is crude, but this _is_ just a test program. The
1145     default size has been increased from 32K to 50K.
1147     2. The code in pcre_study() was using the value of the re argument before
1148     testing it for NULL. (Of course, in any sensible call of the function, it
1149     won't be NULL.)
1151     3. The memmove() emulation function in pcre_internal.h, which is used on
1152     systems that lack both memmove() and bcopy() - that is, hardly ever -
1153     was missing a "static" storage class specifier.
1155     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1156     containing an extended class (one that cannot be represented by a bitmap
1157     because it contains high-valued characters or Unicode property items, e.g.
1158     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1159     pattern, but PCRE should not loop if you do not (it no longer does).
1160     [Detail: two cases were found: (a) a repeated subpattern containing an
1161     extended class; (b) a recursive reference to a subpattern that followed a
1162     previous extended class. It wasn't skipping over the extended class
1163     correctly when UTF-8 mode was not set.]
1165     5. A negated single-character class was not being recognized as fixed-length
1166     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1167     compile error "lookbehind assertion is not fixed length".
1169     6. The RunPerlTest auxiliary script was showing an unexpected difference
1170     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1171     write a Perl script that can interpret lines of an input file either as
1172     byte characters or as UTF-8, which is what "perltest" was being required to
1173     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1174     can't do is switch easily at run time between having the "use utf8;" pragma
1175     or not. In the end, I fudged it by using the RunPerlTest script to insert
1176     "use utf8;" explicitly for the UTF-8 tests.
1178     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1179     the end of the subject string, contrary to the documentation and to what
1180     Perl does. This was true of both matching functions. Now it matches only at
1181     the start of the subject and immediately after *internal* newlines.
1183     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1184     a pointer to an int instead of a pointer to an unsigned long int. This
1185     caused problems on 64-bit systems.
1187     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1188     instance of the 'standard' template library not being so standard".
1190     10. There was no check on the number of named subpatterns nor the maximum
1191     length of a subpattern name. The product of these values is used to compute
1192     the size of the memory block for a compiled pattern. By supplying a very
1193     long subpattern name and a large number of named subpatterns, the size
1194     computation could be caused to overflow. This is now prevented by limiting
1195     the length of names to 32 characters, and the number of named subpatterns
1196     to 10,000.
1198     11. Subpatterns that are repeated with specific counts have to be replicated in
1199     the compiled pattern. The size of memory for this was computed from the
1200     length of the subpattern and the repeat count. The latter is limited to
1201     65535, but there was no limit on the former, meaning that integer overflow
1202     could in principle occur. The compiled length of a repeated subpattern is
1203     now limited to 30,000 bytes in order to prevent this.
1205     12. Added the optional facility to have named substrings with the same name.
1207     13. Added the ability to use a named substring as a condition, using the
1208     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1209     are numbers (not recommended). Forward references are permitted.
1211     14. Added forward references in named backreferences (if you see what I mean).
1213     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1214     pattern could run off the end of the subject. For example, the pattern
1215     "(?s)(.{1,5})"8 did this with the subject "ab".
1217     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1218     PCRE_CASELESS was set when matching characters that were quantified with ?
1219     or *.
1221     17. A character class other than a single negated character that had a minimum
1222     but no maximum quantifier - for example [ab]{6,} - was not handled
1223     correctly by pce_dfa_exec(). It would match only one character.
1225     18. A valid (though odd) pattern that looked like a POSIX character
1226     class but used an invalid character after [ (for example [[,abc,]]) caused
1227     pcre_compile() to give the error "Failed: internal error: code overflow" or
1228     in some cases to crash with a glibc free() error. This could even happen if
1229     the pattern terminated after [[ but there just happened to be a sequence of
1230     letters, a binary zero, and a closing ] in the memory that followed.
1232     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1233     over the years. Originally (before any Unicode support), just the bottom 8
1234     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1235     output from "man perlunicode" includes this:
1237     The regular expression compiler produces polymorphic opcodes. That
1238     is, the pattern adapts to the data and automatically switches to
1239     the Unicode character scheme when presented with Unicode data--or
1240     instead uses a traditional byte scheme when presented with byte
1241     data.
1243     Sadly, a wide octal escape does not cause a switch, and in a string with
1244     no other multibyte characters, these octal escapes are treated as before.
1245     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1246     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1247     Unicode string.
1249     I have not perpetrated such confusion in PCRE. Up till now, it took just
1250     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1251     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1252     translate to the appropriate multibyte character.
1254     29. Applied some refactoring to reduce the number of warnings from Microsoft
1255     and Borland compilers. This has included removing the fudge introduced
1256     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1257     a warning about an unused variable.
1259     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1260     characters since release 4.0, because Perl (from release 5.004) does not.
1261     [Or at least, is documented not to: some releases seem to be in conflict
1262     with the documentation.] However, when a pattern was studied with
1263     pcre_study() and all its branches started with \s, PCRE still included VT
1264     as a possible starting character. Of course, this did no harm; it just
1265     caused an unnecessary match attempt.
1267     22. Removed a now-redundant internal flag bit that recorded the fact that case
1268     dependency changed within the pattern. This was once needed for "required
1269     byte" processing, but is no longer used. This recovers a now-scarce options
1270     bit. Also moved the least significant internal flag bit to the most-
1271     significant bit of the word, which was not previously used (hangover from
1272     the days when it was an int rather than a uint) to free up another bit for
1273     the future.
1275     23. Added support for CRLF line endings as well as CR and LF. As well as the
1276     default being selectable at build time, it can now be changed at runtime
1277     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1278     specify that it is scanning data with non-default line endings.
1280     24. Changed the definition of CXXLINK to make it agree with the definition of
1281     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1283     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1284     recursions. This makes a big different to stack usage for some patterns.
1286     26. If a subpattern containing a named recursion or subroutine reference such
1287     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1288     the space required for the compiled pattern went wrong and gave too small a
1289     value. Depending on the environment, this could lead to "Failed: internal
1290     error: code overflow at offset 49" or "glibc detected double free or
1291     corruption" errors.
1293     27. Applied patches from Google (a) to support the new newline modes and (b) to
1294     advance over multibyte UTF-8 characters in GlobalReplace.
1296     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1297     difference for some implementation of PCRE in some Windows version.
1299     29. Added some extra testing facilities to pcretest:
1301     \q<number> in a data line sets the "match limit" value
1302     \Q<number> in a data line sets the "match recursion limt" value
1303     -S <number> sets the stack size, where <number> is in megabytes
1305     The -S option isn't available for Windows.
1308 nigel 89 Version 6.6 06-Feb-06
1309     ---------------------
1311     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1312     in pcreposix.h. I have copied the definition from pcre.h.
1314     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1315     because pcre.h is no longer a built file.
1317     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1318     not normally included in the compiled code.
1321 nigel 87 Version 6.5 01-Feb-06
1322     ---------------------
1324     1. When using the partial match feature with pcre_dfa_exec(), it was not
1325     anchoring the second and subsequent partial matches at the new starting
1326     point. This could lead to incorrect results. For example, with the pattern
1327     /1234/, partially matching against "123" and then "a4" gave a match.
1329     2. Changes to pcregrep:
1331     (a) All non-match returns from pcre_exec() were being treated as failures
1332     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1333     error message is output. Some extra information is given for the
1335     probably the only errors that are likely to be caused by users (by
1336     specifying a regex that has nested indefinite repeats, for instance).
1337     If there are more than 20 of these errors, pcregrep is abandoned.
1339     (b) A binary zero was treated as data while matching, but terminated the
1340     output line if it was written out. This has been fixed: binary zeroes
1341     are now no different to any other data bytes.
1343     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1344     used to set a locale for matching. The --locale=xxxx long option has
1345     been added (no short equivalent) to specify a locale explicitly on the
1346     pcregrep command, overriding the environment variables.
1348     (d) When -B was used with -n, some line numbers in the output were one less
1349     than they should have been.
1351     (e) Added the -o (--only-matching) option.
1353     (f) If -A or -C was used with -c (count only), some lines of context were
1354     accidentally printed for the final match.
1356     (g) Added the -H (--with-filename) option.
1358     (h) The combination of options -rh failed to suppress file names for files
1359     that were found from directory arguments.
1361     (i) Added the -D (--devices) and -d (--directories) options.
1363     (j) Added the -F (--fixed-strings) option.
1365     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1367     (l) Added the --colo(u)r option.
1369     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1370     is not present by default.
1372     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1373     items such as (?R) or (?1), when the recursion could match a number of
1374     alternatives. If it matched one of the alternatives, but subsequently,
1375     outside the recursion, there was a failure, the code tried to back up into
1376     the recursion. However, because of the way PCRE is implemented, this is not
1377     possible, and the result was an incorrect result from the match.
1379     In order to prevent this happening, the specification of recursion has
1380     been changed so that all such subpatterns are automatically treated as
1381     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1383     4. I had overlooked the fact that, in some locales, there are characters for
1384     which isalpha() is true but neither isupper() nor islower() are true. In
1385     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1386     and ordfeminine) are like this. This affected the treatment of \w and \W
1387     when they appeared in character classes, but not when they appeared outside
1388     a character class. The bit map for "word" characters is now created
1389     separately from the results of isalnum() instead of just taking it from the
1390     upper, lower, and digit maps. (Plus the underscore character, of course.)
1392     5. The above bug also affected the handling of POSIX character classes such as
1393     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1394     permanent tables. Instead, the bit maps for such a class were previously
1395     created as the appropriate unions of the upper, lower, and digit bitmaps.
1396     Now they are created by subtraction from the [[:word:]] class, which has
1397     its own bitmap.
1399     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1400     It is created by subtracting the vertical space characters (\x09, \x0a,
1401     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1402     subtraction was done in the overall bitmap for a character class, meaning
1403     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1404     be recognized. This bug has been fixed.
1406     7. Patches from the folks at Google:
1408     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1409     real life, but is still worth protecting against".
1411     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1412     regular expressions".
1414     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1415     have it.
1417     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1418     "configure" and the latter not, in order to fix a problem somebody had
1419     with compiling the Arg class on HP-UX.
1421     (e) Improve the error-handling of the C++ wrapper a little bit.
1423     (f) New tests for checking recursion limiting.
1425     8. The pcre_memmove() function, which is used only if the environment does not
1426     have a standard memmove() function (and is therefore rarely compiled),
1427     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1428     returning a result (though PCRE never actually uses the result).
1430     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1431     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1432     returned instead of calling malloc() with an overflowing number that would
1433     most likely cause subsequent chaos.
1435     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1437     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1438     with this option is matched, the nmatch and pmatch options of regexec() are
1439     ignored.
1441     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1442     provided in case anyone wants to the the POSIX interface with UTF-8
1443     strings.
1445     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1446     C++ linking (needed for some HP-UX environments).
1448     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1449     (unused parameter) and in the pcre_printint() function (omitted "default"
1450     switch label when the default is to do nothing).
1452     15. Added some code to make it possible, when PCRE is compiled as a C++
1453     library, to replace subject pointers for pcre_exec() with a smart pointer
1454     class, thus making it possible to process discontinuous strings.
1456     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1457     much the same function. They were added by different people who were trying
1458     to make PCRE easy to compile on non-Unix systems. It has been suggested
1459     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1460     for compiling on Windows systems. I have therefore replaced it with
1461     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1462     defaults to "extern" for C or "extern C" for C++, which works fine on
1463     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1464     SCOPE with something explicit in config.h. In addition:
1466     (a) pcreposix.h still had just "extern" instead of either of these macros;
1467     I have replaced it with PCRE_DATA_SCOPE.
1469     (b) Functions such as _pcre_xclass(), which are internal to the library,
1470     but external in the C sense, all had PCRE_EXPORT in their definitions.
1471     This is apparently wrong for the Windows case, so I have removed it.
1472     (It makes no difference on Unix-like systems.)
1474     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1475     of recursive calls to match(). This is different to MATCH_LIMIT because
1476     that limits the total number of calls to match(), not all of which increase
1477     the depth of recursion. Limiting the recursion depth limits the amount of
1478     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1479     when PCRE is compiled, and changed at run time. A patch from Google adds
1480     this functionality to the C++ interface.
1482     18. Changes to the handling of Unicode character properties:
1484     (a) Updated the table to Unicode 4.1.0.
1486     (b) Recognize characters that are not in the table as "Cn" (undefined).
1488     (c) I revised the way the table is implemented to a much improved format
1489     which includes recognition of ranges. It now supports the ranges that
1490     are defined in UnicodeData.txt, and it also amalgamates other
1491     characters into ranges. This has reduced the number of entries in the
1492     table from around 16,000 to around 3,000, thus reducing its size
1493     considerably. I realized I did not need to use a tree structure after
1494     all - a binary chop search is just as efficient. Having reduced the
1495     number of entries, I extended their size from 6 bytes to 8 bytes to
1496     allow for more data.
1498     (d) Added support for Unicode script names via properties such as \p{Han}.
1500     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1501     matching that character.
1503     20. When matching a repeated Unicode property with a minimum greater than zero,
1504     (for example \pL{2,}), PCRE could look past the end of the subject if it
1505     reached it while seeking the minimum number of characters. This could
1506     happen only if some of the characters were more than one byte long, because
1507     there is a check for at least the minimum number of bytes.
1509     21. Refactored the implementation of \p and \P so as to be more general, to
1510     allow for more different types of property in future. This has changed the
1511     compiled form incompatibly. Anybody with saved compiled patterns that use
1512     \p or \P will have to recompile them.
1514     22. Added "Any" and "L&" to the supported property types.
1516     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1517     but give a compile time error if the value is greater than 0xff.
1519     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1520     accidentally not being installed or uninstalled.
1522     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1523     made were to insert the current release number. This seemed silly, because
1524     it made things harder for people building PCRE on systems that don't run
1525     "configure". I have turned pcre.h into a distributed file, no longer built
1526     by "configure", with the version identification directly included. There is
1527     no longer a pcre.h.in file.
1529     However, this change necessitated a change to the pcre-config script as
1530     well. It is built from pcre-config.in, and one of the substitutions was the
1531     release number. I have updated configure.ac so that ./configure now finds
1532     the release number by grepping pcre.h.
1534     26. Added the ability to run the tests under valgrind.
1537 nigel 85 Version 6.4 05-Sep-05
1538     ---------------------
1540     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1541     "--" to be printed when multiple files were scanned, even when none of the
1542     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1543     consider it to be a bug, and have restored the previous behaviour.
1545     2. A couple of code tidies to get rid of compiler warnings.
1547     3. The pcretest program used to cheat by referring to symbols in the library
1548     whose names begin with _pcre_. These are internal symbols that are not
1549     really supposed to be visible externally, and in some environments it is
1550     possible to suppress them. The cheating is now confined to including
1551     certain files from the library's source, which is a bit cleaner.
1553     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1554     file's purpose clearer.
1556     5. Reorganized pcre_ucp_findchar().
1559 nigel 83 Version 6.3 15-Aug-05
1560     ---------------------
1562     1. The file libpcre.pc.in did not have general read permission in the tarball.
1564     2. There were some problems when building without C++ support:
1566     (a) If C++ support was not built, "make install" and "make test" still
1567     tried to test it.
1569     (b) There were problems when the value of CXX was explicitly set. Some
1570     changes have been made to try to fix these, and ...
1572     (c) --disable-cpp can now be used to explicitly disable C++ support.
1574     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1575     backslash in a target when C++ was disabled. This confuses some
1576     versions of "make", apparently. Using an intermediate variable solves
1577     this. (Same for CPP_LOBJ.)
1579     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1580     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1581     necessary on certain architectures.
1583     4. Added a setting of -export-symbols-regex to the link command to remove
1584     those symbols that are exported in the C sense, but actually are local
1585     within the library, and not documented. Their names all begin with
1586     "_pcre_". This is not a perfect job, because (a) we have to except some
1587     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1588     available (and never for static libraries). I have made a note to try to
1589     find a way round (a) in the future.
1592 nigel 81 Version 6.2 01-Aug-05
1593     ---------------------
1595     1. There was no test for integer overflow of quantifier values. A construction
1596     such as {1111111111111111} would give undefined results. What is worse, if
1597     a minimum quantifier for a parenthesized subpattern overflowed and became
1598     negative, the calculation of the memory size went wrong. This could have
1599     led to memory overwriting.
1601     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1603     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1604     operating environments where this matters.
1606     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1607     PCRE options from within the C++ wrapper.
1609     5. Named capturing subpatterns were not being correctly counted when a pattern
1610     was compiled. This caused two problems: (a) If there were more than 100
1611     such subpatterns, the calculation of the memory needed for the whole
1612     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1613     back references of the form \12, where the number was greater than 9, were
1614     not recognized as back references, even though there were sufficient
1615     previous subpatterns.
1617     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1618     versions of gcc, e.g. 2.95.4.
1621 nigel 79 Version 6.1 21-Jun-05
1622     ---------------------
1624     1. There was one reference to the variable "posix" in pcretest.c that was not
1625     surrounded by "#if !defined NOPOSIX".
1627     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1628     the cross-check on the old pcre_info() function, for the benefit of the
1629     cut-down version of PCRE that is currently imported into Exim.
1631     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1632     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1633     patterns that start (?i) but I don't think that matters. The use of (?i) is
1634     just an example; this all applies to the other options as well.
1636     4. Since libtool seems to echo the compile commands it is issuing, the output
1637     from "make" can be reduced a bit by putting "@" in front of each libtool
1638     compile command.
1640     5. Patch from the folks at Google for configure.in to be a bit more thorough
1641     in checking for a suitable C++ installation before trying to compile the
1642     C++ stuff. This should fix a reported problem when a compiler was present,
1643     but no suitable headers.
1645     6. The man pages all had just "PCRE" as their title. I have changed them to
1646     be the relevant file name. I have also arranged that these names are
1647     retained in the file doc/pcre.txt, which is a concatenation in text format
1648     of all the man pages except the little individual ones for each function.
1650     7. The NON-UNIX-USE file had not been updated for the different set of source
1651     files that come with release 6. I also added a few comments about the C++
1652     wrapper.
1655 nigel 77 Version 6.0 07-Jun-05
1656     ---------------------
1658     1. Some minor internal re-organization to help with my DFA experiments.
1660     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1661     didn't matter for the library itself when fully configured, but did matter
1662     when compiling without UCP support, or within Exim, where the ucp files are
1663     not imported.
1665     3. Refactoring of the library code to split up the various functions into
1666     different source modules. The addition of the new DFA matching code (see
1667     below) to a single monolithic source would have made it really too
1668     unwieldy, quite apart from causing all the code to be include in a
1669     statically linked application, when only some functions are used. This is
1670     relevant even without the DFA addition now that patterns can be compiled in
1671     one application and matched in another.
1673     The downside of splitting up is that there have to be some external
1674     functions and data tables that are used internally in different modules of
1675     the library but which are not part of the API. These have all had their
1676     names changed to start with "_pcre_" so that they are unlikely to clash
1677     with other external names.
1679     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1680     a different (DFA) algorithm. Although it is slower than the original
1681     function, it does have some advantages for certain types of matching
1682     problem.
1684     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1685     including restarting after a partial match.
1687     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1688     defined when compiling for Windows was sent to me. I have put it into the
1689     code, though I have no means of testing or verifying it.
1691     7. Added the pcre_refcount() auxiliary function.
1693     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1694     match before or at the first newline in the subject string. In pcretest,
1695     the /f option on a pattern can be used to set this.
1697     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1698     would behave wrongly. This has been present in PCRE since release 4.0.
1700     10. A number of changes to the pcregrep command:
1702     (a) Refactored how -x works; insert ^(...)$ instead of setting
1703     PCRE_ANCHORED and checking the length, in preparation for adding
1704     something similar for -w.
1706     (b) Added the -w (match as a word) option.
1708     (c) Refactored the way lines are read and buffered so as to have more
1709     than one at a time available.
1711     (d) Implemented a pcregrep test script.
1713     (e) Added the -M (multiline match) option. This allows patterns to match
1714     over several lines of the subject. The buffering ensures that at least
1715     8K, or the rest of the document (whichever is the shorter) is available
1716     for matching (and similarly the previous 8K for lookbehind assertions).
1718     (f) Changed the --help output so that it now says
1720     -w, --word-regex(p)
1722     instead of two lines, one with "regex" and the other with "regexp"
1723     because that confused at least one person since the short forms are the
1724     same. (This required a bit of code, as the output is generated
1725     automatically from a table. It wasn't just a text change.)
1727     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1728     option but starts with a hyphen. Could be a pattern or a path name
1729     starting with a hyphen, for instance.
1731     (h) "-" can be given as a file name to represent stdin.
1733     (i) When file names are being printed, "(standard input)" is used for
1734     the standard input, for compatibility with GNU grep. Previously
1735     "<stdin>" was used.
1737     (j) The option --label=xxx can be used to supply a name to be used for
1738     stdin when file names are being printed. There is no short form.
1740     (k) Re-factored the options decoding logic because we are going to add
1741     two more options that take data. Such options can now be given in four
1742     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1744     (l) Added the -A, -B, and -C options for requesting that lines of context
1745     around matches be printed.
1747     (m) Added the -L option to print the names of files that do not contain
1748     any matching lines, that is, the complement of -l.
1750     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1751     continue to scan other files.
1753     (o) The -s option was incorrectly implemented. For compatibility with other
1754     greps, it now suppresses the error message for a non-existent or non-
1755     accessible file (but not the return code). There is a new option called
1756     -q that suppresses the output of matching lines, which was what -s was
1757     previously doing.
1759     (p) Added --include and --exclude options to specify files for inclusion
1760     and exclusion when recursing.
1762     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1763     Hopefully, it now does.
1765     12. Missing cast in pcre_study().
1767     13. Added an "uninstall" target to the makefile.
1769     14. Replaced "extern" in the function prototypes in Makefile.in with
1770     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1771     world, but is set differently for Windows.
1773     15. Added a second compiling function called pcre_compile2(). The only
1774     difference is that it has an extra argument, which is a pointer to an
1775     integer error code. When there is a compile-time failure, this is set
1776     non-zero, in addition to the error test pointer being set to point to an
1777     error message. The new argument may be NULL if no error number is required
1778     (but then you may as well call pcre_compile(), which is now just a
1779     wrapper). This facility is provided because some applications need a
1780     numeric error indication, but it has also enabled me to tidy up the way
1781     compile-time errors are handled in the POSIX wrapper.
1783     16. Added VPATH=.libs to the makefile; this should help when building with one
1784     prefix path and installing with another. (Or so I'm told by someone who
1785     knows more about this stuff than I do.)
1787     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1788     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1789     match everything, including newlines. This is not POSIX-compatible, but
1790     somebody wanted the feature. From pcretest it can be activated by using
1791     both the P and the s flags.
1793     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1795     19. libpcre.pc was being incorrectly installed as executable.
1797     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1798     it now also looks for '\r' so that it will work unmodified on Windows.
1800     21. Added Google's contributed C++ wrapper to the distribution.
1802     22. Added some untidy missing memory free() calls in pcretest, to keep
1803     Electric Fence happy when testing.
1807 nigel 75 Version 5.0 13-Sep-04
1808     ---------------------
1810     1. Internal change: literal characters are no longer packed up into items
1811     containing multiple characters in a single byte-string. Each character
1812     is now matched using a separate opcode. However, there may be more than one
1813     byte in the character in UTF-8 mode.
1815     2. The pcre_callout_block structure has two new fields: pattern_position and
1816     next_item_length. These contain the offset in the pattern to the next match
1817     item, and its length, respectively.
1819     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1820     insertion of callouts before each pattern item. Added the /C option to
1821     pcretest to make use of this.
1823     4. On the advice of a Windows user, the lines
1825     #if defined(_WIN32) || defined(WIN32)
1826     _setmode( _fileno( stdout ), 0x8000 );
1827     #endif /* defined(_WIN32) || defined(WIN32) */
1829     have been added to the source of pcretest. This apparently does useful
1830     magic in relation to line terminators.
1832     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1833     for the benefit of those environments where the "b" makes a difference.
1835     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1836     to know about it. I have put a hack into configure.in that adds in code
1837     to set GCC=yes if CC=icc. This seems to end up at a point in the
1838     generated configure script that is early enough to affect the setting of
1839     compiler options, which is what is needed, but I have no means of testing
1840     whether it really works. (The user who reported this had patched the
1841     generated configure script, which of course I cannot do.)
1843     LATER: After change 22 below (new libtool files), the configure script
1844     seems to know about icc (and also ecc). Therefore, I have commented out
1845     this hack in configure.in.
1847     7. Added support for pkg-config (2 patches were sent in).
1849     8. Negated POSIX character classes that used a combination of internal tables
1850     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1851     [[:^ascii]]. Typically, they would match almost any characters. The other
1852     POSIX classes were not broken in this way.
1854     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1855     to find the match, as PCRE was deluded into thinking that the match had to
1856     start at the start point or following a newline. The same bug applied to
1857     patterns with negative forward assertions or any backward assertions
1858     preceding ".*" at the start, unless the pattern required a fixed first
1859     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1861     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1862     starting at the last subject character, bytes beyond the end of the subject
1863     string were read.
1865     11. Renamed the variable "class" as "classbits" to make life easier for C++
1866     users. (Previously there was a macro definition, but it apparently wasn't
1867     enough.)
1869     12. Added the new field "tables" to the extra data so that tables can be passed
1870     in at exec time, or the internal tables can be re-selected. This allows
1871     a compiled regex to be saved and re-used at a later time by a different
1872     program that might have everything at different addresses.
1874     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1875     -R library as well as a -L library.
1877     14. The debugging options of pcretest (-d on the command line or D on a
1878     pattern) showed incorrect output for anything following an extended class
1879     that contained multibyte characters and which was followed by a quantifier.
1881     15. Added optional support for general category Unicode character properties
1882     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1883     support. It adds about 90K to the size of the library. The meanings of the
1884     inbuilt class escapes such as \d and \s have NOT been changed.
1886     16. Updated pcredemo.c to include calls to free() to release the memory for the
1887     compiled pattern.
1889     17. The generated file chartables.c was being created in the source directory
1890     instead of in the building directory. This caused the build to fail if the
1891     source directory was different from the building directory, and was
1892     read-only.
1894     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1895     file. No doubt somebody will tell me if they don't make sense... Also added
1896     Dan Mooney's comments about building on OpenVMS.
1898     19. Added support for partial matching via the PCRE_PARTIAL option for
1899     pcre_exec() and the \P data escape in pcretest.
1901     20. Extended pcretest with 3 new pattern features:
1903     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1904     write the compiled pattern to the file whose name is "rest-of-line".
1905     This is a straight binary dump of the data, with the saved pointer to
1906     the character tables forced to be NULL. The study data, if any, is
1907     written too. After writing, pcretest reads a new pattern.
1909     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1910     compiled pattern from the given file. There must not be any
1911     occurrences of "<" in the file name (pretty unlikely); if there are,
1912     pcretest will instead treat the initial "<" as a pattern delimiter.
1913     After reading in the pattern, pcretest goes on to read data lines as
1914     usual.
1916     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1917     and 16-bit fields in a compiled pattern, to simulate a pattern that
1918     was compiled on a host of opposite endianness.
1920     21. The pcre-exec() function can now cope with patterns that were compiled on
1921     hosts of opposite endianness, with this restriction:
1923     As for any compiled expression that is saved and used later, the tables
1924     pointer field cannot be preserved; the extra_data field in the arguments
1925     to pcre_exec() should be used to pass in a tables address if a value
1926     other than the default internal tables were used at compile time.
1928     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1929     now diagnosed as an error. Previously, most of the time, a negative number
1930     would have been treated as zero, but if in addition "ovector" was passed as
1931     NULL, a crash could occur.
1933     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1934     new versions from the libtool 1.5 distribution (the last one is a copy of
1935     a file called libtool.m4). This seems to have fixed the need to patch
1936     "configure" to support Darwin 1.3 (which I used to do). However, I still
1937     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1938     workstation).
1940     24. Changed the PCRE licence to be the more standard "BSD" licence.
1943 nigel 73 Version 4.5 01-Dec-03
1944     ---------------------
1946     1. There has been some re-arrangement of the code for the match() function so
1947     that it can be compiled in a version that does not call itself recursively.
1948     Instead, it keeps those local variables that need separate instances for
1949     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1950     needs to "recurse". Keeping track of where control must go is done by means
1951     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1952     hide most of the details from the main code, and operates only if
1953     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1954     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1955     operating.
1957     To make it easier for callers to provide specially tailored get/free
1958     functions for this usage, two new functions, pcre_stack_malloc, and
1959     pcre_stack_free, are used. They are always called in strict stacking order,
1960     and the size of block requested is always the same.
1962     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1963     PCRE has been compiled to use the stack or the heap for recursion. The
1964     -C option of pcretest uses this to show which version is compiled.
1966     A new data escape \S, is added to pcretest; it causes the amounts of store
1967     obtained and freed by both kinds of malloc/free at match time to be added
1968     to the output.
1970     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1971     what's available on my current Linux desktop machine.
1973     3. When matching a UTF-8 string, the test for a valid string at the start has
1974     been extended. If start_offset is not zero, PCRE now checks that it points
1975     to a byte that is the start of a UTF-8 character. If not, it returns
1976     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1977     this is necessary because there may be backward assertions in the pattern.
1978     When matching the same subject several times, it may save resources to use
1979     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1981     4. The code for checking the validity of UTF-8 strings has been tightened so
1982     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1983     containing "overlong sequences".
1985     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1986     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1987     should have been "&", but it just so happened that all the cases this let
1988     through by mistake were picked up later in the function.
1990     6. I had used a variable called "isblank" - this is a C99 function, causing
1991     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1993     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1994     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1995     so the version is shown; (c) stop "make test" echoing "./RunTest".
1997     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1999     9. The prototype for memmove() for systems that don't have it was using
2000     size_t, but the inclusion of the header that defines size_t was later. I've
2001     moved the #includes for the C headers earlier to avoid this.
2003     10. Added some adjustments to the code to make it easier to compiler on certain
2004     special systems:
2006     (a) Some "const" qualifiers were missing.
2007     (b) Added the macro EXPORT before all exported functions; by default this
2008     is defined to be empty.
2009     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2010     that it reads its output file name as an argument instead of writing
2011     to the standard output and assuming this can be redirected.
2013     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2014     class containing characters with values greater than 255, PCRE compilation
2015     went into a loop.
2017     12. A recursive reference to a subpattern that was within another subpattern
2018     that had a minimum quantifier of zero caused PCRE to crash. For example,
2019     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2020     recursion. If the recursively-called subpattern itself had a zero repeat,
2021     that was OK.
2023     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2024     buffer into which it was copied (for escape processing) was still set at
2025     1024, so long lines caused crashes.
2027     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2028     "internal error: code overflow...". This applied to any character class
2029     that was followed by a possessive quantifier.
2031     15. Modified the Makefile to add libpcre.la as a prerequisite for
2032     libpcreposix.la because I was told this is needed for a parallel build to
2033     work.
2035     16. If a pattern that contained .* following optional items at the start was
2036     studied, the wrong optimizing data was generated, leading to matching
2037     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2038     matching string must start with a or b or c. The correct conclusion for
2039     this pattern is that a match can start with any character.
2042 nigel 71 Version 4.4 13-Aug-03
2043     ---------------------
2045     1. In UTF-8 mode, a character class containing characters with values between
2046     127 and 255 was not handled correctly if the compiled pattern was studied.
2047     In fixing this, I have also improved the studying algorithm for such
2048     classes (slightly).
2050     2. Three internal functions had redundant arguments passed to them. Removal
2051     might give a very teeny performance improvement.
2053     3. Documentation bug: the value of the capture_top field in a callout is *one
2054     more than* the number of the hightest numbered captured substring.
2056     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2057     in incorrectly linking with a previously installed version. They now link
2058     explicitly with libpcre.la.
2060     5. configure.in no longer needs to recognize Cygwin specially.
2062     6. A problem in pcre.in for Windows platforms is fixed.
2064     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2065     pcretest, it used to include the size of the study block as part of its
2066     output. Unfortunately, the structure contains a field that has a different
2067     size on different hardware architectures. This meant that the tests that
2068     showed this size failed. As the block is currently always of a fixed size,
2069     this information isn't actually particularly useful in pcretest output, so
2070     I have just removed it.
2072     8. Three pre-processor statements accidentally did not start in column 1.
2073     Sadly, there are *still* compilers around that complain, even though
2074     standard C has not required this for well over a decade. Sigh.
2076     9. In pcretest, the code for checking callouts passed small integers in the
2077     callout_data field, which is a void * field. However, some picky compilers
2078     complained about the casts involved for this on 64-bit systems. Now
2079     pcretest passes the address of the small integer instead, which should get
2080     rid of the warnings.
2082     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2083     both compile and run time, and gives an error if an invalid UTF-8 sequence
2084     is found. There is a option for disabling this check in cases where the
2085     string is known to be correct and/or the maximum performance is wanted.
2087     11. In response to a bug report, I changed one line in Makefile.in from
2089     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2090     to
2091     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2093     to look similar to other lines, but I have no way of telling whether this
2094     is the right thing to do, as I do not use Windows. No doubt I'll get told
2095     if it's wrong...
2098 nigel 69 Version 4.3 21-May-03
2099     ---------------------
2101     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2102     Makefile.
2104     2. Some refactoring to improve the quality of the code:
2106     (i) The utf8_table... variables are now declared "const".
2108     (ii) The code for \cx, which used the "case flipping" table to upper case
2109     lower case letters, now just substracts 32. This is ASCII-specific,
2110     but the whole concept of \cx is ASCII-specific, so it seems
2111     reasonable.
2113     (iii) PCRE was using its character types table to recognize decimal and
2114     hexadecimal digits in the pattern. This is silly, because it handles
2115     only 0-9, a-f, and A-F, but the character types table is locale-
2116     specific, which means strange things might happen. A private
2117     table is now used for this - though it costs 256 bytes, a table is
2118     much faster than multiple explicit tests. Of course, the standard
2119     character types table is still used for matching digits in subject
2120     strings against \d.
2122     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2123     ending in _t are). So I've renamed it as ESC_tee.
2125     3. The first argument for regexec() in the POSIX wrapper should have been
2126     defined as "const".
2128     4. Changed pcretest to use malloc() for its buffers so that they can be
2129     Electric Fenced for debugging.
2131     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2132     to read one or more bytes before the start of the subject string. Often this
2133     had no effect on PCRE's behaviour, but in some circumstances it could
2134     provoke a segmentation fault.
2136     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2137     to try to read one or more bytes before the start of the subject string.
2139     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2140     UTF-8 support could misbehave in various ways if the subject string
2141     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2142     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2143     back over UTF-8 characters.)
2146 nigel 67 Version 4.2 14-Apr-03
2147     ---------------------
2149     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2151     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2152     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2153     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2154     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2155     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2156     and BUILD_EXEEXT
2157     Note: automatic setting of the BUILD variables is not yet working
2158     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2159     compile-time but not at link-time
2160     [LINK]: use for linking executables only
2161     make different versions for Windows and non-Windows
2162     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2163     libraries
2164     [LINK_FOR_BUILD]: new variable
2165     [OBJEXT]: use throughout
2166     [EXEEXT]: use throughout
2167     <winshared>: new target
2168     <wininstall>: new target
2169     <dftables.o>: use native compiler
2170     <dftables>: use native linker
2171     <install>: handle Windows platform correctly
2172     <clean>: ditto
2173     <check>: ditto
2174     copy DLL to top builddir before testing
2176     As part of these changes, -no-undefined was removed again. This was reported
2177     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2178     in any case.
2180     3. Some tidies to get rid of compiler warnings:
2182     . In the match_data structure, match_limit was an unsigned long int, whereas
2183     match_call_count was an int. I've made them both unsigned long ints.
2185     . In pcretest the fact that a const uschar * doesn't automatically cast to
2186     a void * provoked a warning.
2188     . Turning on some more compiler warnings threw up some "shadow" variables
2189     and a few more missing casts.
2191     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2192     option, a class that contained a single character with a value between 128
2193     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2195     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2196     option, a class that contained several characters, but with at least one
2197     whose value was between 128 and 255 caused PCRE to crash.
2200 nigel 65 Version 4.1 12-Mar-03
2201     ---------------------
2202 nigel 63
2203 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2204     needed, and a string in dftables.c that was longer than standard compilers are
2205     required to support.
2207     2. Compiling with Sun's compiler found a few more places where the code could
2208     be tidied up in order to avoid warnings.
2210     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2211     first of these names is deprecated in the latest Autoconf in favour of the name
2212     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2213     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2214     analogy I have changed it to CFLAGS_FOR_BUILD.
2216     4. Added -no-undefined to the linking command in the Makefile, because this is
2217     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2218     linking step for the pcreposix library.
2220     5. PCRE was failing to diagnose the case of two named groups with the same
2221     name.
2223     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2224     literal character that is needed in the subject for a match, and scans along to
2225     ensure that it is present before embarking on the full matching process. This
2226     saves time in cases of nested unlimited repeats that are never going to match.
2227     Problem: the scan can take a lot of time if the subject is very long (e.g.
2228     megabytes), thus penalizing straightforward matches. It is now done only if the
2229     amount of subject to be scanned is less than 1000 bytes.
2231     7. A lesser problem with the same optimization is that it was recording the
2232     first character of an anchored pattern as "needed", thus provoking a search
2233     right along the subject, even when the first match of the pattern was going to
2234     fail. The "needed" character is now not set for anchored patterns, unless it
2235     follows something in the pattern that is of non-fixed length. Thus, it still
2236     fulfils its original purpose of finding quick non-matches in cases of nested
2237     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2240     Version 4.0 17-Feb-03
2241     ---------------------
2243 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2244     extended to the end of string, PCRE compiled incorrect data. This could lead to
2245     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2247     2. Moved to autoconf 2.53 and libtool 1.4.2.
2249     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2250     the special perltest8 script is no longer needed - all the tests can be run
2251     from a single perltest script.
2253     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2254     by \s. It has now been removed in PCRE. This means it isn't recognized as
2255     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2256     class [:space:] *does* include VT, thereby creating a mess.
2258     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2259     space and tab.
2261     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2262     its new features into the main test script, reducing the number of scripts.
2264     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2265     were backward compatible, and made the (?i) apply to the whole pattern, as if
2266     /i were given. Now it behaves more logically, and applies the option setting
2267     only to what follows. PCRE has been changed to follow suit. However, if it
2268     finds options settings right at the start of the pattern, it extracts them into
2269     the global options, as before. Thus, they show up in the info data.
2271     8. Added support for the \Q...\E escape sequence. Characters in between are
2272     treated as literals. This is slightly different from Perl in that $ and @ are
2273     also handled as literals inside the quotes. In Perl, they will cause variable
2274     interpolation. Note the following examples:
2276     Pattern PCRE matches Perl matches
2278     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2279     \Qabc\$xyz\E abc\$xyz abc\$xyz
2280     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2282     For compatibility with Perl, \Q...\E sequences are recognized inside character
2283     classes as well as outside them.
2285     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2286     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2287     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2288     signed/unsigned warnings.
2290     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2291     option for pcretest, so I've replaced it by a simple function that does just
2292     that job.
2294     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2295     "pcregrep -".
2297     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2298     Java package. This provides some syntactic sugar for simple cases of what my
2299     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2300     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2301     item, you can use this simplified notation. Note that only makes sense with
2302     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2303     greediness, whatever the setting of the PCRE_UNGREEDY option.
2305     13. A change of greediness default within a pattern was not taking effect at
2306     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2307     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2308     was abstracted outside.
2310     14. PCRE now supports the \G assertion. It is true when the current matching
2311     position is at the start point of the match. This differs from \A when the
2312     starting offset is non-zero. Used with the /g option of pcretest (or similar
2313     code), it works in the same way as it does for Perl's /g option. If all
2314     alternatives of a regex begin with \G, the expression is anchored to the start
2315     match position, and the "anchored" flag is set in the compiled expression.
2317     15. Some bugs concerning the handling of certain option changes within patterns
2318     have been fixed. These applied to options other than (?ims). For example,
2319     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2320     been the other way round. Some of this was related to change 7 above.
2322     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2323     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2324     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2325     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2327     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2328     mode. Unlike ".", it always matches newline, whatever the setting of
2329     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2330     assertions. Perl allows it, but it doesn't (in general) work because it can't
2331     calculate the length of the lookbehind. At least, that's the case for Perl
2332     5.8.0 - I've been told they are going to document that it doesn't work in
2333     future.
2335     18. Added an error diagnosis for escapes that PCRE does not support: these are
2336     \L, \l, \N, \P, \p, \U, \u, and \X.
2338     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2339     reading past the end of the pattern in cases such as /[abcd/.
2341     20. PCRE was getting more memory than necessary for patterns with classes that
2342     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2344     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2345     compiling PCRE for use with Virtual Pascal.
2347     22. Small fix to the Makefile to make it work properly if the build is done
2348     outside the source tree.
2350     23. Added a new extension: a condition to go with recursion. If a conditional
2351     subpattern starts with (?(R) the "true" branch is used if recursion has
2352     happened, whereas the "false" branch is used only at the top level.
2354     24. When there was a very long string of literal characters (over 255 bytes
2355     without UTF support, over 250 bytes with UTF support), the computation of how
2356     much memory was required could be incorrect, leading to segfaults or other
2357     strange effects.
2359     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2360     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2361     there was a subsequent back reference to those brackets. This meant that, for
2362     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2363     possible to check for precisely this case. All we can do is abandon the
2364     optimization if .* occurs inside capturing brackets when there are any back
2365     references whatsoever. (See below for a better fix that came later.)
2367     26. The handling of the optimization for finding the first character of a
2368     non-anchored pattern, and for finding a character that is required later in the
2369     match were failing in some cases. This didn't break the matching; it just
2370     failed to optimize when it could. The way this is done has been re-implemented.
2372     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2374     28. Added a new feature that provides some of the functionality that Perl
2375     provides with (?{...}). The facility is termed a "callout". The way it is done
2376     in PCRE is for the caller to provide an optional function, by setting
2377     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2378     global variable. By default it is unset, which disables all calling out. To get
2379     the function called, the regex must include (?C) at appropriate points. This
2380     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2381     This provides a means of identifying different callout points. When PCRE
2382     reaches such a point in the regex, if pcre_callout has been set, the external
2383     function is called. It is provided with data in a structure called
2384     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2385     matching continues; if it returns a non-zero value, the match at the current
2386     point fails. However, backtracking will occur if possible. [This was changed
2387     later and other features added - see item 49 below.]
2389     29. pcretest is upgraded to test the callout functionality. It provides a
2390     callout function that displays information. By default, it shows the start of
2391     the match and the current position in the text. There are some new data escapes
2392     to vary what happens:
2394     \C+ in addition, show current contents of captured substrings
2395     \C- do not supply a callout function
2396     \C!n return 1 when callout number n is reached
2397     \C!n!m return 1 when callout number n is reached for the mth time
2399     30. If pcregrep was called with the -l option and just a single file name, it
2400     output "<stdin>" if a match was found, instead of the file name.
2402     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2403     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2404     pcre_exec(). This saves a malloc/free per call. The default value of
2405     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2406     when configuring.
2408     32. The default maximum size of a compiled pattern is 64K. There have been a
2409     few cases of people hitting this limit. The code now uses macros to handle the
2410     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2411     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2412     configuring. Tests 2 and 5 work only with 2-byte links because they output
2413     debugging information about compiled patterns.
2415     33. Internal code re-arrangements:
2417     (a) Moved the debugging function for printing out a compiled regex into
2418     its own source file (printint.c) and used #include to pull it into
2419     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2420     separate copies.
2422     (b) Defined the list of op-code names for debugging as a macro in
2423     internal.h so that it is next to the definition of the opcodes.
2425     (c) Defined a table of op-code lengths for simpler skipping along compiled
2426     code. This is again a macro in internal.h so that it is next to the
2427     definition of the opcodes.
2429     34. Added support for recursive calls to individual subpatterns, along the
2430     lines of Robin Houston's patch (but implemented somewhat differently).
2432     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2433     allow it to read and process whole directories in Win32. This code was
2434     contributed by Lionel Fourquaux; it has not been tested by me.
2436     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2437     used to name a group. Names consist of alphanumerics and underscores, and must
2438     be unique. Back references use the syntax (?P=name) and recursive calls use
2439     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2440     numbers. The function pcre_fullinfo() can be used after compilation to extract
2441     a name/number map. There are three relevant calls:
2443     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2444     PCRE_INFO_NAMECOUNT yields the number of entries
2445     PCRE_INFO_NAMETABLE yields a pointer to the map.
2447     The map is a vector of fixed-size entries. The size of each entry depends on
2448     the length of the longest name used. The first two bytes of each entry are the
2449     group number, most significant byte first. There follows the corresponding
2450     name, zero terminated. The names are in alphabetical order.
2452     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2453     case instead of 255. Making it the same both with and without UTF-8 support
2454     means that the same test output works with both.
2456     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2457     calling malloc() with a zero argument.
2459     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2460     optimization. I've improved things by keeping a bitmap of backreferences with
2461     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2462     fact referenced, the optimization can be applied. It is unlikely that a
2463     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2464     the match to follow \n) will appear inside brackets with a number greater than
2465     31, but if it does, any back reference > 31 suppresses the optimization.
2467     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2468     of disabling numbered capturing parentheses. Any opening parenthesis that is
2469     not followed by ? behaves as if it were followed by ?: but named parentheses
2470     can still be used for capturing (and they will acquire numbers in the usual
2471     way).
2473     41. Redesigned the return codes from the match() function into yes/no/error so
2474     that errors can be passed back from deep inside the nested calls. A malloc
2475     failure while inside a recursive subpattern call now causes the
2476     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2478     42. It is now possible to set a limit on the number of times the match()
2479     function is called in a call to pcre_exec(). This facility makes it possible to
2480     limit the amount of recursion and backtracking, though not in a directly
2481     obvious way, because the match() function is used in a number of different
2482     circumstances. The count starts from zero for each position in the subject
2483     string (for non-anchored patterns). The default limit is, for compatibility, a
2484     large number, namely 10 000 000. You can change this in two ways:
2486     (a) When configuring PCRE before making, you can use --with-match-limit=n
2487     to set a default value for the compiled library.
2489     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2490     a different value is set. See 45 below.
2492     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2494     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2495     of things that can be changed at compile time. The first argument specifies
2496     what is wanted and the second points to where the information is to be placed.
2497     The current list of available information is:
2501     The output is an integer that is set to one if UTF-8 support is available;
2502     otherwise it is set to zero.
2506     The output is an integer that it set to the value of the code that is used for
2507     newline. It is either LF (10) or CR (13).
2511     The output is an integer that contains the number of bytes used for internal
2512     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2516     The output is an integer that contains the threshold above which the POSIX
2517     interface uses malloc() for output vectors. See item 31 above.
2521     The output is an unsigned integer that contains the default limit of the number
2522     of match() calls in a pcre_exec() execution. See 42 above.
2524     44. pcretest has been upgraded by the addition of the -C option. This causes it
2525     to extract all the available output from the new pcre_config() function, and to
2526     output it. The program then exits immediately.
2528     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2529     order to support additional features. One way would have been to define
2530     pcre_exec2() (for example) with extra arguments, but this would not have been
2531     extensible, and would also have required all calls to the original function to
2532     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2533     is used for passing in "extra" data from pcre_study().
2535     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2536     contains the following fields:
2538     flags a bitmap indicating which of the following fields are set
2539     study_data opaque data from pcre_study()
2540     match_limit a way of specifying a limit on match() calls for a specific
2541     call to pcre_exec()
2542     callout_data data for callouts (see 49 below)
2544     The flag bits are also defined in pcre.h, and are
2550     The pcre_study() function now returns one of these new pcre_extra blocks, with
2551     the actual study data pointed to by the study_data field, and the
2552     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2553     before. That is, this change is entirely upwards-compatible and requires no
2554     change to existing code.
2556     If you want to pass in additional data to pcre_exec(), you can either place it
2557     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2558     block.
2560     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2561     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2562     times with different match limits, until it finds the minimum value needed for
2563     pcre_exec() to complete. The value is then output. This can be instructive; for
2564     most simple matches the number is quite small, but for pathological cases it
2565     gets very large very quickly.
2567     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2568     returns the size of the data block pointed to by the study_data field in a
2569     pcre_extra block, that is, the value that was passed as the argument to
2570     pcre_malloc() when PCRE was getting memory in which to place the information
2571     created by pcre_study(). The fourth argument should point to a size_t variable.
2572     pcretest has been extended so that this information is shown after a successful
2573     pcre_study() call when information about the compiled regex is being displayed.
2575     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2576     because what follows is always an absolute path. (Later: it turns out that this
2577     is more than cosmetic for MinGW, because it doesn't like empty path
2578     components.)
2580     49. Some changes have been made to the callout feature (see 28 above):
2582     (i) A callout function now has three choices for what it returns:
2584     0 => success, carry on matching
2585     > 0 => failure at this point, but backtrack if possible
2586     < 0 => serious error, return this value from pcre_exec()
2588     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2589     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2590     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2591     use by callout functions. It will never be used by PCRE itself.
2593     (ii) The pcre_extra structure (see 45 above) has a void * field called
2594     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2595     pcre_callout_block structure has a field of the same name. The contents of
2596     the field passed in the pcre_extra structure are passed to the callout
2597     function in the corresponding field in the callout block. This makes it
2598     easier to use the same callout-containing regex from multiple threads. For
2599     testing, the pcretest program has a new data escape
2601     \C*n pass the number n (may be negative) as callout_data
2603     If the callout function in pcretest receives a non-zero value as
2604     callout_data, it returns that value.
2606     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2607     there were some redundant $(CFLAGS) in commands that are now specified as
2608     $(LINK), which already includes $(CFLAGS).
2610     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2611     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2612     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2613     one-byte characters throughout. Note that case-insensitive matching applies
2614     only to characters whose values are less than 256. PCRE doesn't support the
2615     notion of cases for higher-valued characters.
2617     (i) A character class whose characters are all within 0-255 is handled as
2618     a bit map, and the map is inverted for negative classes. Previously, a
2619     character > 255 always failed to match such a class; however it should
2620     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2622     (ii) A negated character class with a single character < 255 is coded as
2623     "not this character" (OP_NOT). This wasn't working properly when the test
2624     character was multibyte, either singly or repeated.
2626     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2627     mode, for example: \x{100}{2,3}.
2629     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2630     singly or repeated) now correctly test multibyte characters. However,
2631     PCRE doesn't recognize any characters with values greater than 255 as
2632     digits, spaces, or word characters. Such characters always match \D, \S,
2633     and \W, and never match \d, \s, or \w.
2635     (v) Classes may now contain characters and character ranges with values
2636     greater than 255. For example: [ab\x{100}-\x{400}].
2638     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2639     PCRE in UTF-8 mode.
2641     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2642     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2643     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2644     value.)
2646     53. The single man page has become too large. I have therefore split it up into
2647     a number of separate man pages. These also give rise to individual HTML pages;
2648     these are now put in a separate directory, and there is an index.html page that
2649     lists them all. Some hyperlinking between the pages has been installed.
2651     54. Added convenience functions for handling named capturing parentheses.
2653     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2654     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2655     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2656     are faulted.
2658     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2659     calling configure. These values are used when compiling the dftables.c program
2660     which is run to generate the source of the default character tables. They
2661     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2662     you will need to set these values.
2664     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2667     Version 3.9 02-Jan-02
2668 nigel 61 ---------------------
2670     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2672     2. If --disable-static was given, the building process failed when trying to
2673     build pcretest and pcregrep. (For some reason it was using libtool to compile
2674     them, which is not right, as they aren't part of the library.)
2677 nigel 59 Version 3.8 18-Dec-01
2678     ---------------------
2680     1. The experimental UTF-8 code was completely screwed up. It was packing the
2681     bytes in the wrong order. How dumb can you get?
2684 nigel 57 Version 3.7 29-Oct-01
2685     ---------------------
2687     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2688     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2689     this didn't happen under Solaris 8, where I normally test things.
2691 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2692     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2693     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2694     this fix an hour or so after the initial 3.7 release.)
2695 nigel 57
2696 nigel 59
2697 nigel 55 Version 3.6 23-Oct-01
2698     ---------------------
2700     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2701     offsets passed as NULL with zero offset count.
2703     2. The config.guess and config.sub files had not been updated when I moved to
2704     the latest autoconf.
2707 nigel 53 Version 3.5 15-Aug-01
2708     ---------------------
2709 nigel 5
2710 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2711     had been forgotten.
2713     2. By using declared but undefined structures, we can avoid using "void"
2714     definitions in pcre.h while keeping the internal definitions of the structures
2715     private.
2717     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2718     user point of view, this means that both static and shared libraries are built
2719     by default, but this can be individually controlled. More of the work of
2720     handling this static/shared cases is now inside libtool instead of PCRE's make
2721     file.
2723     4. The pcretest utility is now installed along with pcregrep because it is
2724     useful for users (to test regexs) and by doing this, it automatically gets
2725     relinked by libtool. The documentation has been turned into a man page, so
2726     there are now .1, .txt, and .html versions in /doc.
2728     5. Upgrades to pcregrep:
2729     (i) Added long-form option names like gnu grep.
2730     (ii) Added --help to list all options with an explanatory phrase.
2731     (iii) Added -r, --recursive to recurse into sub-directories.
2732     (iv) Added -f, --file to read patterns from a file.
2734     6. pcre_exec() was referring to its "code" argument before testing that
2735     argument for NULL (and giving an error if it was NULL).
2737     7. Upgraded Makefile.in to allow for compiling in a different directory from
2738     the source directory.
2740     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2741     options bits, the pointer it was passed was to an int instead of to an unsigned
2742     long int. This mattered only on 64-bit systems.
2744     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2745     generated) instead of pcre.in, which it its source. Also made the same change
2746     in several of the .c files.
2748     10. A new release of gcc defines printf() as a macro, which broke pcretest
2749     because it had an ifdef in the middle of a string argument for printf(). Fixed
2750     by using separate calls to printf().
2752     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2753     script, to force use of CR or LF instead of \n in the source. On non-Unix
2754     systems, the value can be set in config.h.
2756     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2757     absolute limit. Changed the text of the error message to make this clear, and
2758     likewise updated the man page.
2760     13. The limit of 99 on the number of capturing subpatterns has been removed.
2761     The new limit is 65535, which I hope will not be a "real" limit.
2764 nigel 51 Version 3.4 22-Aug-00
2765     ---------------------
2767     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2769     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2772 nigel 49 Version 3.3 01-Aug-00
2773     ---------------------
2775     1. If an octal character was given, but the value was greater than \377, it
2776     was not getting masked to the least significant bits, as documented. This could
2777     lead to crashes in some systems.
2779     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2780     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2782     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2783     These just pass their arguments on to (pcre_free)(), but they are provided
2784     because some uses of PCRE bind it to non-C systems that can call its functions,
2785     but cannot call free() or pcre_free() directly.
2787     4. Add "make test" as a synonym for "make check". Corrected some comments in
2788     the Makefile.
2790     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2791     Makefile.
2793     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2794     command called pgrep for grepping around the active processes.
2796     7. Added the beginnings of support for UTF-8 character strings.
2798     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2799     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2800     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2801     out for the ar command.)
2804 nigel 47 Version 3.2 12-May-00
2805     ---------------------
2807     This is purely a bug fixing release.
2809     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2810     of ZA. This was just one example of several cases that could provoke this bug,
2811     which was introduced by change 9 of version 2.00. The code for breaking
2812     infinite loops after an iteration that matches an empty string was't working
2813     correctly.
2815     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2816     when matched against abbab (for example). After matching an empty string, it
2817     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2818     caused it to match further down the string than it should.
2820     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2821     was there because it doesn't seem to be needed, and it causes trouble on some
2822     systems, as it is not a Standard C header. It has been removed.
2824     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2825     were reported on the Macintosh. The changes were from
2827     while ((c = *(++ptr)) != 0 && c != '\n');
2828     to
2829     while ((c = *(++ptr)) != 0 && c != '\n') ;
2831     Totally extraordinary, but if that's what it takes...
2833     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2834     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2835     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2836     assumes the way PCRE uses memmove() (always moving upwards).
2838     6. PCRE is being used in one environment where strchr() is not available. There
2839     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2840     faster code anyway.
2843 nigel 45 Version 3.1 09-Feb-00
2844     ---------------------
2846     The only change in this release is the fixing of some bugs in Makefile.in for
2847     the "install" target:
2849     (1) It was failing to install pcreposix.h.
2851     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2854 nigel 43 Version 3.0 01-Feb-00
2855     ---------------------
2856 nigel 41
2857     1. Add support for the /+ modifier to perltest (to output $` like it does in
2858     pcretest).
2860     2. Add support for the /g modifier to perltest.
2862     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2863     matches null strings.
2865     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2866     pattern. Perl treats empty patterns specially - it reuses the most recent
2867     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2868     effect.
2870     5. The POSIX interface was broken in that it was just handing over the POSIX
2871     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2872     required a bigger vector, with some working space on the end. This means that
2873     the POSIX wrapper now has to get and free some memory, and copy the results.
2875 nigel 43 6. Added some simple autoconf support, placing the test data and the
2876     documentation in separate directories, re-organizing some of the
2877     information files, and making it build pcre-config (a GNU standard). Also added
2878     libtool support for building PCRE as a shared library, which is now the
2879     default.
2880 nigel 41
2881 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2882     09 are not valid octal constants. Single digits will be used for minor values
2883     less than 10.
2885     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2886     existing programs that set these in the POSIX interface can use PCRE without
2887     modification.
2889     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2890     return all that pcre_info() returns, plus additional data. The pcre_info()
2891     function is retained for compatibility, but is considered to be obsolete.
2893     10. Added experimental recursion feature (?R) to handle one common case that
2894     Perl 5.6 will be able to do with (?p{...}).
2896     11. Added support for POSIX character classes like [:alpha:], which Perl is
2897     adopting.
2900 nigel 39 Version 2.08 31-Aug-99
2901     ----------------------
2903     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2904     trying to match at the startoffset position, but instead was moving forward to
2905     the next newline as if a previous match had failed.
2907     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2908     and could get into a loop if a null string was matched other than at the start
2909     of the subject.
2911     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2912     be distinguished at compile time, and for completeness also added PCRE_DATE.
2914     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2915     in GnuWin32 environments.
2918 nigel 37 Version 2.07 29-Jul-99
2919     ----------------------
2921     1. The documentation is now supplied in plain text form and HTML as well as in
2922     the form of man page sources.
2924     2. C++ compilers don't like assigning (void *) values to other pointer types.
2925     In particular this affects malloc(). Although there is no problem in Standard
2926     C, I've put in casts to keep C++ compilers happy.
2928     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2929     should be (const char *).
2931     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2932     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2933     However, I haven't made this a standard facility. The documentation doesn't
2934     mention it, and the Makefile doesn't support it.
2936     5. The Makefile now contains an "install" target, with editable destinations at
2937     the top of the file. The pcretest program is not installed.
2939     6. pgrep -V now gives the PCRE version number and date.
2941     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2942     causing the entire string to be ignored, instead of just the last character.
2944     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2945     non-matching string, it can take a very, very long time, even for strings of
2946     quite modest length, because of the nested recursion. PCRE now does better in
2947     some of these cases. It does this by remembering the last required literal
2948     character in the pattern, and pre-searching the subject to ensure it is present
2949     before running the real match. In other words, it applies a heuristic to detect
2950     some types of certain failure quickly, and in the above example, if presented
2951     with a string that has no trailing " it gives "no match" very quickly.
2953     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2954     other alternatives are tried instead.
2957 nigel 35 Version 2.06 09-Jun-99
2958     ----------------------
2960     1. Change pcretest's output for amount of store used to show just the code
2961     space, because the remainder (the data block) varies in size between 32-bit and
2962     64-bit systems.
2964     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2965     start matching at. This allows lookbehinds to work when searching for multiple
2966     occurrences in a string.
2968     3. Added additional options to pcretest for testing multiple occurrences:
2970     /+ outputs the rest of the string that follows a match
2971     /g loops for multiple occurrences, using the new startoffset argument
2972     /G loops for multiple occurrences by passing an incremented pointer
2974     4. PCRE wasn't doing the "first character" optimization for patterns starting
2975     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2976     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2977     the letter 'x'. On long subject strings, this gives a significant speed-up.
2980 nigel 33 Version 2.05 21-Apr-99
2981     ----------------------
2983     1. Changed the type of magic_number from int to long int so that it works
2984     properly on 16-bit systems.
2986     2. Fixed a bug which caused patterns starting with .* not to work correctly
2987     when the subject string contained newline characters. PCRE was assuming
2988     anchoring for such patterns in all cases, which is not correct because .* will
2989     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2990     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2991     must be retried after every newline in the subject.
2994 nigel 31 Version 2.04 18-Feb-99
2995     ----------------------
2997     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2998     computation of the store needed to hold the pattern was incorrect (too large).
2999     If such patterns were nested a few deep, this could multiply and become a real
3000     problem.
3002     2. Added /M option to pcretest to show the memory requirement of a specific
3003     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3005     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3006     compiled in such a way that the backtracking after subsequent failure was
3007     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3008     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3011 nigel 29 Version 2.03 02-Feb-99
3012     ----------------------
3014     1. Fixed typo and small mistake in man page.
3016 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3017     LICENCE file containing the conditions.
3018 nigel 29
3019     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3020     Perl, that is the internal \ allows the delimiter to be included in the
3021     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3022     the final delimiter, add \ to the end of the pattern (to test the error).
3024     4. Added the convenience functions for extracting substrings after a successful
3025     match. Updated pcretest to make it able to test these functions.
3028 nigel 27 Version 2.02 14-Jan-99
3029     ----------------------
3031     1. Initialized the working variables associated with each extraction so that
3032     their saving and restoring doesn't refer to uninitialized store.
3034     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3035     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3036     fix the problem.
3038     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3039     calls, and wasn't printing the correct value for compiling calls. Increased the
3040     default value of LOOPREPEAT, and the number of significant figures in the
3041     times.
3043     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3045     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3046     a building problem on Windows NT with a FAT file system.
3049 nigel 25 Version 2.01 21-Oct-98
3050     ----------------------
3052     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3053     to character tables built by pcre_maketables() in the current locale. If NULL
3054     is passed, the default tables are used.
3057 nigel 23 Version 2.00 24-Sep-98
3058 nigel 21 ----------------------
3060 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3061     it any more.
3063     2. Allow quantification of (?>) groups, and make it work correctly.
3065     3. The first character computation wasn't working for (?>) groups.
3067     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3068     end of the subject) and add 5.005's \z, which really does match only at the
3069     very end of the subject.
3071     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3073     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3074     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3075     localized options. All options to pcre_study() were also removed.
3077     7. Add other new features from 5.005:
3079     $(?<= positive lookbehind
3080     $(?<! negative lookbehind
3081     (?imsx-imsx) added the unsetting capability
3082     such a setting is global if at outer level; local otherwise
3083     (?imsx-imsx:) non-capturing groups with option setting
3084     (?(cond)re|re) conditional pattern matching
3086     A backreference to itself in a repeated group matches the previous
3087     captured string.
3089     8. General tidying up of studying (both automatic and via "study")
3090     consequential on the addition of new assertions.
3092     9. As in 5.005, unlimited repeated groups that could match an empty substring
3093     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3094     runtime if any iteration does actually match an empty substring.
3096     10. Include the RunTest script in the distribution.
3098     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3099     discrepancies, some of which were old and were also with respect to 5.004. They
3100     have now been fixed.
3103     Version 1.09 28-Apr-98
3104     ----------------------
3106 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3107     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3108     program crashes, or just wrong answers. This did not apply to negated classes
3109     containing more than one character, or to minima other than one.
3112 nigel 19 Version 1.08 27-Mar-98
3113     ----------------------
3115     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3117     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3118     latter must appear before anything that relies on it in the pattern.
3121 nigel 17 Version 1.07 16-Feb-98
3122     ----------------------
3124     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3125     repeat of a potentially empty string).
3128 nigel 15 Version 1.06 23-Jan-98
3129     ----------------------
3131     1. Added Markus Oberhumer's little patches for C++.
3133     2. Literal strings longer than 255 characters were broken.
3136 nigel 13 Version 1.05 23-Dec-97
3137     ----------------------
3139     1. Negated character classes containing more than one character were failing if
3140     PCRE_CASELESS was set at run time.
3143 nigel 11 Version 1.04 19-Dec-97
3144     ----------------------
3146     1. Corrected the man page, where some "const" qualifiers had been omitted.
3148     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3149     input syntax.
3151     3. Fixed memory leak which occurred when a regex with back references was
3152     matched with an offsets vector that wasn't big enough. The temporary memory
3153     that is used in this case wasn't being freed if the match failed.
3155     4. Tidied pcretest to ensure it frees memory that it gets.
3157     5. Temporary memory was being obtained in the case where the passed offsets
3158     vector was exactly big enough.
3160     6. Corrected definition of offsetof() from change 5 below.
3162     7. I had screwed up change 6 below and broken the rules for the use of
3163     setjmp(). Now fixed.
3166 nigel 9 Version 1.03 18-Dec-97
3167     ----------------------
3169     1. A erroneous regex with a missing opening parenthesis was correctly
3170     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3171     on some systems.
3173     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3174     it was reported that one broken compiler failed on the former because "code" is
3175     also an independent variable.
3177     3. The erroneous regex a[]b caused an array overrun reference.
3179     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3180     fail on data ending with that character. (It was going on too far, and checking
3181     the next character, typically a binary zero.) This was specific to the
3182     optimized code for single-character negative classes.
3184     5. Added a contributed patch from the TIN world which does the following:
3186     + Add an undef for memmove, in case the the system defines a macro for it.
3188     + Add a definition of offsetof(), in case there isn't one. (I don't know
3189     the reason behind this - offsetof() is part of the ANSI standard - but
3190     it does no harm).
3192     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3193     most of the places where whitespace preceded '#'. I have given up and
3194     allowed the remaining 2 cases to be at the margin.
3196     + Rename some variables in pcre to eliminate shadowing. This seems very
3197     pedantic, but does no harm, of course.
3199     6. Moved the call to setjmp() into its own function, to get rid of warnings
3200     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3202     7. Constructs such as \d{8,} were compiling into the equivalent of
3203 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3204 nigel 9 outcome, but in this particular case used more store than had been allocated,
3205     which caused the bug to be discovered because it threw up an internal error.
3207     8. The debugging code in both pcre and pcretest for outputting the compiled
3208     form of a regex was going wrong in the case of back references followed by
3209     curly-bracketed repeats.
3212 nigel 7 Version 1.02 12-Dec-97
3213     ----------------------
3215     1. Typos in pcre.3 and comments in the source fixed.
3217     2. Applied a contributed patch to get rid of places where it used to remove
3218     'const' from variables, and fixed some signed/unsigned and uninitialized
3219     variable warnings.
3221     3. Added the "runtest" target to Makefile.
3223     4. Set default compiler flag to -O2 rather than just -O.
3226 nigel 5 Version 1.01 19-Nov-97
3227     ----------------------
3229     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3230     like /([ab]*)*/, that is, for classes with more than one character in them.
3232     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3233     as /((?>a*))*/ (a PCRE_EXTRA facility).
3236     Version 1.00 18-Nov-97
3237     ----------------------
3239     1. Added compile-time macros to support systems such as SunOS4 which don't have
3240     memmove() or strerror() but have other things that can be used instead.
3242     2. Arranged that "make clean" removes the executables.
3245 nigel 3 Version 0.99 27-Oct-97
3246     ----------------------
3248     1. Fixed bug in code for optimizing classes with only one character. It was
3249     initializing a 32-byte map regardless, which could cause it to run off the end
3250     of the memory it had got.
3252     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3255     Version 0.98 22-Oct-97
3256     ----------------------
3258     1. Fixed bug in code for handling temporary memory usage when there are more
3259     back references than supplied space in the ovector. This could cause segfaults.
3262     Version 0.97 21-Oct-97
3263     ----------------------
3265     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3267     2. Optimized negated single characters not to use a bit map.
3269     3. Brought error texts together as macro definitions; clarified some of them;
3270     fixed one that was wrong - it said "range out of order" when it meant "invalid
3271     escape sequence".
3273     4. Changed some char * arguments to const char *.
3275     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3277     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3278     pcretest.
3281     Version 0.96 16-Oct-97
3282     ----------------------
3284     1. Added a simple "pgrep" utility to the distribution.
3286     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3287     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3288     where "ddd" means "one or more decimal digits".
3290     3. Fixed serious bug. If a pattern had a back reference, but the call to
3291     pcre_exec() didn't supply a large enough ovector to record the related
3292     identifying subpattern, the match always failed. PCRE now remembers the number
3293     of the largest back reference, and gets some temporary memory in which to save
3294     the offsets during matching if necessary, in order to ensure that
3295     backreferences always work.
3297     4. Increased the compatibility with Perl in a number of ways:
3299     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3300     to request this handling. The option can be set at compile or exec time.
3302     (b) $ matches before a terminating newline by default; an option
3303     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3304     mode). The option can be set at compile or exec time.
3306     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3307     the same as Perl's. If the decimal number it represents is less than 10
3308     or there aren't that many previous left capturing parentheses, an octal
3309     escape is read. Inside a character class, it's always an octal escape,
3310     even if it is a single digit.
3312     (d) An escaped but undefined alphabetic character is taken as a literal,
3313     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3314     escapes.
3316     (e) {0} is now permitted. (The previous item is removed from the compiled
3317     pattern).
3319     5. Changed all the names of code files so that the basic parts are no longer
3320     than 10 characters, and abolished the teeny "globals.c" file.
3322     6. Changed the handling of character classes; they are now done with a 32-byte
3323     bit map always.
3325     7. Added the -d and /D options to pcretest to make it possible to look at the
3326     internals of compilation without having to recompile pcre.
3329     Version 0.95 23-Sep-97
3330     ----------------------
3332     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3333     \x20 at the start of a run of normal characters. These were being treated as
3334     real characters, instead of the source characters being re-checked.
3337     Version 0.94 18-Sep-97
3338     ----------------------
3340     1. The functions are now thread-safe, with the caveat that the global variables
3341     containing pointers to malloc() and free() or alternative functions are the
3342     same for all threads.
3344     2. Get pcre_study() to generate a bitmap of initial characters for non-
3345     anchored patterns when this is possible, and use it if passed to pcre_exec().
3348     Version 0.93 15-Sep-97
3349     ----------------------
3351     1. /(b)|(:+)/ was computing an incorrect first character.
3353     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3354     but not actually doing anything yet.
3356     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3357     as Perl does (e.g. [-az] or [az-]).
3359     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3360     all possible positions.
3362     5. Split up into different modules to avoid including unneeded functions in a
3363     compiled binary. However, compile and exec are still in one module. The "study"
3364     function is split off.
3366     6. The character tables are now in a separate module whose source is generated
3367     by an auxiliary program - but can then be edited by hand if required. There are
3368     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3369     toupper() in the code.
3371     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3372     make them global. Abolish the function for setting them, as the caller can now
3373     set them directly.
3376     Version 0.92 11-Sep-97
3377     ----------------------
3379     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3380     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3382     2. Caseless matching was not working in character classes if the characters in
3383     the pattern were in upper case.
3385     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3387     4. Make PCRE_ANCHORED public and accept as a compile option.
3389     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3390     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3391     pass them.
3393     6. Give an error if bad option bits passed at compile or run time.
3395     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3396     pcretest to cause it to pass that flag.
3398     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3399     options, and the first character, if set.
3401     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3404     Version 0.91 10-Sep-97
3405     ----------------------
3407     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3408     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3410     2. PCRE was looping on encountering an indefinitely repeated back reference to
3411     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3412     Perl does - treats the match as successful.
3414     ****


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