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Revision 380 - (hide annotations) (download)
Tue Mar 3 12:32:47 2009 UTC (5 years, 4 months ago) by ph10
File size: 161808 byte(s)
The pattern (?(?=.*b)b|^) was incorrectly processed as requiring a match at the 
start of the subject or after a newline.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 376 Version 7.9 xx-xxx-09
5     ---------------------
6    
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.
13    
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.
18    
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.
21    
22     4. The pcregrep documentation said spaces were inserted as well as colons (or
23     hyphens) following file names and line numbers when outputting matching
24     lines. This is not true; no spaces are inserted. I have also clarified the
25     wording for the --colour (or --color) option.
26 ph10 377
27 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
28     was not coloured; this is different to GNU grep, so I have changed it to be
29     the same.
30    
31     6. When --colo(u)r was used in pcregrep, only the first matching substring in
32     each matching line was coloured. Now it goes on to look for further matches
33     of any of the test patterns, which is the same behaviour as GNU grep.
34 ph10 379
35     7. A pattern that could match an empty string could cause pcregrep to loop; it
36     doesn't make sense to accept an empty string match in pcregrep, so I have
37     locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38     seems to be how GNU grep behaves.
39 ph10 380
40     8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
41     start or after a newline", because the conditional assertion was not being
42     skipped when checking for this condition.
43 ph10 376
44    
45 ph10 374 Version 7.8 05-Sep-08
46 ph10 349 ---------------------
47    
48     1. Replaced UCP searching code with optimized version as implemented for Ad
49     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
50 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
51     to 5 times on some simple patterns that I tested. Permission was given to
52     distribute the MultiStage2.py script that generates the tables (it's not in
53     the tarball, but is in the Subversion repository).
54 ph10 349
55 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
56     scripts.
57 ph10 358
58 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
59     a group with a zero qualifier. The result of the study could be incorrect,
60 ph10 358 or the function might crash, depending on the pattern.
61    
62     4. Caseless matching was not working for non-ASCII characters in back
63 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
64 ph10 358 It now works when Unicode Property Support is available.
65    
66 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
67     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
68     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
69 ph10 358 truncation.
70 ph10 349
71 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
72    
73 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
74     pointers, in case they are 64-bit values.
75 ph10 371
76     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
77     test 2 if it fails.
78    
79 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
80 ph10 371 and a #define of that name to empty if it is not externally set. This is to
81     allow users of MSVC to set it if necessary.
82    
83     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
84 ph10 359 the convenience functions in the pcre_get.c source file.
85 ph10 371
86 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
87     could cause overwriting and/or a crash. This command provoked a crash in
88 ph10 371 some environments:
89    
90     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
91    
92 ph10 360 This potential security problem was recorded as CVE-2008-2371.
93 ph10 371
94 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
95     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
96 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
97 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
98     pcretest so that it places the subject at the end of its malloc-ed buffer.
99 ph10 371
100 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
101 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
102    
103 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
104 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
105     first line. This applied both to normal and DFA matching.
106    
107 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
108 ph10 371 /^[^d]*?$/8 failed to match "abc".
109 ph10 351
110 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
111    
112     17. Make it more clear in the documentation that values returned from
113 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
114 ph10 357
115 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
116 ph10 368
117 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
118     supplied by Stefan Weber. I made a further small update for 7.8 because
119 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
120     replaced by pcre_ucd.c.
121 ph10 371
122 ph10 373
123 ph10 347 Version 7.7 07-May-08
124 ph10 321 ---------------------
125    
126     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
127 ph10 345 a string to a long long, pretend we don't even have a long long." This is
128 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
129 ph10 345
130 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
131     pre-7.6 versions, which defined a global no_arg variable instead of putting
132 ph10 332 it in the RE class. (See also #8 below.)
133 ph10 345
134     3. Remove a line of dead code, identified by coverity and reported by Nuno
135     Lopes.
136    
137 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
138 ph10 321
139 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
140 ph10 345 of files, instead of just to the final components.
141    
142 ph10 324 (2) If there was more than one level of directory, the subdirectories were
143     skipped unless they satisfied the include/exclude conditions. This is
144     inconsistent with GNU grep (and could even be seen as contrary to the
145     pcregrep specification - which I improved to make it absolutely clear).
146     The action now is always to scan all levels of directory, and just
147     apply the include/exclude patterns to regular files.
148 ph10 345
149 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
150 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
151    
152 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
153 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
154 ph10 326 doesn't support NULs in patterns.
155 ph10 345
156     7. Added some missing "const"s to declarations of static tables in
157     pcre_compile.c and pcre_dfa_exec.c.
158    
159 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
160 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
161 ph10 345 first patch. And a third patch - this was a messy problem.)
162 ph10 321
163 ph10 345 9. Applied Craig's patch to remove the use of push_back().
164    
165 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
166     matching function regexec().
167 ph10 345
168     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
169     which, however, unlike Perl's \g{...}, are subroutine calls, not back
170 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
171     Oniguruma does).
172 ph10 345
173     12. Previously, a group with a zero repeat such as (...){0} was completely
174 ph10 335 omitted from the compiled regex. However, this means that if the group
175     was called as a subroutine from elsewhere in the pattern, things went wrong
176 ph10 345 (an internal error was given). Such groups are now left in the compiled
177     pattern, with a new opcode that causes them to be skipped at execution
178 ph10 335 time.
179 ph10 345
180 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
181     to the way PCRE behaves:
182 ph10 345
183 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
184 ph10 345
185     (b) A back reference to an unmatched subpattern matches an empty string
186 ph10 336 (Perl fails the current match path).
187 ph10 345
188 ph10 341 (c) A data ] in a character class must be notated as \] because if the
189 ph10 345 first data character in a class is ], it defines an empty class. (In
190 ph10 341 Perl it is not possible to have an empty class.) The empty class []
191     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
192     The negative empty class [^] matches any one character, independently
193     of the DOTALL setting.
194 ph10 345
195     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
196 ph10 340 non-existent subpattern following a character class starting with ']' and
197     containing () gave an internal compiling error instead of "reference to
198     non-existent subpattern". Fortunately, when the pattern did exist, the
199 ph10 345 compiled code was correct. (When scanning forwards to check for the
200 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
201 ph10 345 the class, so got the count wrong. When actually compiling, the reference
202 ph10 340 was subsequently set up correctly.)
203 ph10 345
204 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
205 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
206     other assertions are supported. I have made pcre_dfa_exec() support
207     (*FAIL).
208    
209 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
210 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
211     cannot be changed at match time, I realized I could make a small
212     improvement to matching performance by compiling OP_ALLANY instead of
213     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
214     on the OP_ANY path.
215    
216     17. Compiling pcretest on Windows with readline support failed without the
217 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
218 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
219    
220 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
221 ph10 345 ncurses library to be included for pcretest when ReadLine support is
222     requested, but also to allow for it to be overridden. This patch came from
223     Daniel Bergström.
224 ph10 347
225 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
226 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
227     any errors with the current Unicode tables. Thanks to Peter Kankowski for
228     spotting this.
229 ph10 324
230 ph10 332
231 ph10 319 Version 7.6 28-Jan-08
232 ph10 300 ---------------------
233    
234 ph10 302 1. A character class containing a very large number of characters with
235     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
236     overflow.
237 ph10 309
238     2. Patch to cut out the "long long" test in pcrecpp_unittest when
239     HAVE_LONG_LONG is not defined.
240    
241 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
242 ph10 304 bring them up to date and include new features. This patch includes:
243 ph10 309
244 ph10 304 - Fixed PH's badly added libz and libbz2 support.
245     - Fixed a problem with static linking.
246 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
247 ph10 304 - Fixed dftables problem and added an option.
248     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
249     HAVE_LONG_LONG.
250     - Added readline support for pcretest.
251 ph10 309 - Added an listing of the option settings after cmake has run.
252    
253 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
254     "pcre.dll" under mingw when using Configure/Make. I added stuff to
255     Makefile.am that cause it to include this special target, without
256     affecting anything else. Note that the same mingw target plus all
257     the other distribution libraries and programs are now supported
258     when configuring with CMake (see 6 below) instead of with
259     Configure/Make.
260 ph10 309
261 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
262     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
263 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
264     solves the problem, but it does no harm.
265 ph10 313
266 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
267 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
268 ph10 314 with CMake, and also correct the comment about stack recursion.
269 ph10 313
270 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
271 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
272     of a program that users should build themselves after PCRE is installed, so
273     building it automatically is not really right. What is more, it gave
274 ph10 312 trouble in some build environments.
275 ph10 300
276 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
277 ph10 308
278 ph10 319
279 ph10 298 Version 7.5 10-Jan-08
280 ph10 263 ---------------------
281    
282     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
283     values in parens when parsing an RE using the C++ wrapper."
284 ph10 286
285 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
286     Characters greater than 255 were excluded from the class instead of being
287     included.
288 ph10 286
289     3. The same bug as (2) above applied to negated POSIX classes such as
290 ph10 265 [:^space:].
291 ph10 286
292 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
293     defined or documented. It seems to have been a typo for PCRE_STATIC, so
294 ph10 286 I have changed it.
295    
296 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
297 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
298     first named subpattern whose name started with "a" (in other words, the
299 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
300     expected" is now given for (?&) (a zero-length name), and this patch also
301     makes it give the same error for \k'' (previously it complained that that
302     was a reference to a non-existent subpattern).
303 ph10 286
304 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
305 ph10 286 this is right because (?- can be followed by option settings as well as by
306 ph10 269 digits. I have, however, made the messages clearer.
307 ph10 286
308 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
309     than the number used in the conditional) now cause a compile-time error.
310     This is actually not compatible with Perl, which accepts such patterns, but
311     treats the conditional as always being FALSE (as PCRE used to), but it
312     seems to me that giving a diagnostic is better.
313 ph10 286
314 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
315 ph10 275 and messages.
316 ph10 286
317     9. Fix two occurrences of "backslash" in comments that should have been
318     "backspace".
319    
320     10. Remove two redundant lines of code that can never be obeyed (their function
321     was moved elsewhere).
322    
323     11. The program that makes PCRE's Unicode character property table had a bug
324     which caused it to generate incorrect table entries for sequences of
325 ph10 277 characters that have the same character type, but are in different scripts.
326 ph10 286 It amalgamated them into a single range, with the script of the first of
327 ph10 277 them. In other words, some characters were in the wrong script. There were
328     thirteen such cases, affecting characters in the following ranges:
329 ph10 286
330 ph10 277 U+002b0 - U+002c1
331     U+0060c - U+0060d
332 ph10 286 U+0061e - U+00612
333 ph10 277 U+0064b - U+0065e
334     U+0074d - U+0076d
335     U+01800 - U+01805
336     U+01d00 - U+01d77
337     U+01d9b - U+01dbf
338     U+0200b - U+0200f
339     U+030fc - U+030fe
340     U+03260 - U+0327f
341     U+0fb46 - U+0fbb1
342     U+10450 - U+1049d
343 ph10 286
344 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
345     compatible with GNU grep in that, if there was more than one match in a
346     line, it showed only the first of them. It now behaves in the same way as
347     GNU grep.
348 ph10 286
349     13. If the -o and -v options were combined for pcregrep, it printed a blank
350     line for every non-matching line. GNU grep prints nothing, and pcregrep now
351     does the same. The return code can be used to tell if there were any
352     non-matching lines.
353    
354 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
355    
356     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
357 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
358 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
359     and both kinds of lookbehind were skipped).
360    
361 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
362 ph10 284 inclusion of <windows.h> to before rather than after the definition of
363     INVALID_FILE_ATTRIBUTES (patch from David Byron).
364 ph10 263
365 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
366 ph10 286 character property caused pcre_compile() to compile bad code, which led at
367     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
368     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
369     caused the error; without that there was no problem.
370 ph10 263
371 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
372 ph10 286
373 ph10 289 19. Added --enable-pcretest-libreadline.
374 ph10 286
375 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
376 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
377 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
378     later patch that removed the other one (the right fix) and added unit tests
379     that check the return values (which was not done before).
380 ph10 292
381 ph10 291 21. Several CMake things:
382 ph10 287
383 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
384 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
385 ph10 288
386 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
387     linked with the newly-built libraries, not previously installed ones.
388 ph10 291
389 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
390 ph10 298
391     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
392     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
393     UTF-8 newline character). The key issue is that the pattern starts .*;
394     this means that the match must be either at the beginning, or after a
395     newline. The bug was in the code for advancing after a failed match and
396     checking that the new position followed a newline. It was not taking
397 ph10 294 account of UTF-8 characters correctly.
398 ph10 298
399     23. PCRE was behaving differently from Perl in the way it recognized POSIX
400     character classes. PCRE was not treating the sequence [:...:] as a
401     character class unless the ... were all letters. Perl, however, seems to
402     allow any characters between [: and :], though of course it rejects as
403     unknown any "names" that contain non-letters, because all the known class
404     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
405     for example, whereas PCRE did not - it did not recognize a POSIX character
406     class. This seemed a bit dangerous, so the code has been changed to be
407     closer to Perl. The behaviour is not identical to Perl, because PCRE will
408     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
409     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
410     Perl does, and where it didn't before.
411    
412 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
413     Windows environments %n is disabled by default.
414 ph10 292
415    
416 ph10 260 Version 7.4 21-Sep-07
417 ph10 230 ---------------------
418    
419     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
420 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
421     LF". That isn't really right - the whole point of the change was to try to
422     help when there was an actual mention of one of the two characters. So now
423     the change happens only if \r or \n (or a literal CR or LF) character is
424 ph10 230 encountered.
425 ph10 231
426     2. The 32-bit options word was also used for 6 internal flags, but the numbers
427     of both had grown to the point where there were only 3 bits left.
428     Fortunately, there was spare space in the data structure, and so I have
429     moved the internal flags into a new 16-bit field to free up more option
430 ph10 230 bits.
431 ph10 231
432     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
433     but did not set the internal JCHANGED flag - either of these is enough to
434     control the way the "get" function works - but the PCRE_INFO_JCHANGED
435     facility is supposed to tell if (?J) was ever used, so now (?J) at the
436 ph10 230 start sets both bits.
437    
438 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
439     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
440 ph10 230
441 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
442    
443     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
444 ph10 233 compatibility, even though it is no longer used.
445 ph10 243
446     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
447 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
448 ph10 259 windows.h file is present (where different names are used). [This was
449 ph10 257 reversed later after testing - see 16 below.]
450 ph10 243
451     8. Changed all #include <config.h> to #include "config.h". There were also
452 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
453 ph10 243
454 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
455 ph10 243 sequence off the lines that it output.
456    
457     10. It was pointed out to me that arrays of string pointers cause lots of
458     relocations when a shared library is dynamically loaded. A technique of
459     using a single long string with a table of offsets can drastically reduce
460     these. I have refactored PCRE in four places to do this. The result is
461 ph10 240 dramatic:
462 ph10 243
463 ph10 240 Originally: 290
464     After changing UCP table: 187
465 ph10 243 After changing error message table: 43
466 ph10 240 After changing table of "verbs" 36
467     After changing table of Posix names 22
468 ph10 243
469 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
470 ph10 247
471 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
472 ph10 247 unicode-properties was also set.
473    
474 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
475 ph10 231
476 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
477     checked only for CRLF.
478 ph10 233
479 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
480    
481 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
482 ph10 253
483 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
484 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
485     entirely. This removes changes made in 7 above.
486 ph10 256
487 ph10 261 17. The CMake files have been updated, and there is now more information about
488     building with CMake in the NON-UNIX-USE document.
489 ph10 257
490 ph10 261
491 ph10 228 Version 7.3 28-Aug-07
492 ph10 157 ---------------------
493    
494 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
495     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
496     brackets there is not right, since it causes compilers to look for an
497     installed pcre.h, not the version that is in the source that is being
498     compiled (which of course may be different). I have changed it back to:
499 ph10 197
500 ph10 189 #include "pcre.h"
501 ph10 197
502     I have a vague recollection that the change was concerned with compiling in
503     different directories, but in the new build system, that is taken care of
504     by the VPATH setting the Makefile.
505    
506 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
507     when the subject happened to end in the byte 0x85 (e.g. if the last
508     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
509     characters but of course it shouldn't be taken as a newline when it is part
510     of another character. The bug was that, for an unlimited repeat of . in
511     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
512     characters when looking for a newline.
513 ph10 197
514     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
515    
516     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
517     in debug output.
518    
519 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
520     long printing in the pcrecpp unittest when running under MinGW.
521 ph10 189
522 ph10 197 6. ESC_K was left out of the EBCDIC table.
523 ph10 189
524 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
525     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
526     limit also applies to "virtual nesting" when a pattern is recursive, and in
527     this case 1000 isn't so big. I have been able to remove this limit at the
528     expense of backing off one optimization in certain circumstances. Normally,
529     when pcre_exec() would call its internal match() function recursively and
530     immediately return the result unconditionally, it uses a "tail recursion"
531     feature to save stack. However, when a subpattern that can match an empty
532     string has an unlimited repetition quantifier, it no longer makes this
533     optimization. That gives it a stack frame in which to save the data for
534     checking that an empty string has been matched. Previously this was taken
535     from the 1000-entry workspace that had been reserved. So now there is no
536     explicit limit, but more stack is used.
537 ph10 189
538 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
539     syntax that is required for Windows, and which was going wrong for the
540     pcreposix and pcrecpp parts of the library. These were overlooked when this
541     problem was solved for the main library.
542 ph10 197
543 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
544     the size of patterns that contain repeated groups with explicit upper
545     limits. As the maximum quantifier is 65535, the maximum group length was
546     set at 30,000 so that the product of these two numbers did not overflow a
547     32-bit integer. However, it turns out that people want to use groups that
548     are longer than 30,000 bytes (though not repeat them that many times).
549     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
550     made it possible to implement the integer overflow checks in a much more
551     dynamic way, which I have now done. The artificial limitation on group
552     length has been removed - we now have only the limit on the total length of
553     the compiled pattern, which depends on the LINK_SIZE setting.
554 ph10 208
555     10. Fixed a bug in the documentation for get/copy named substring when
556     duplicate names are permitted. If none of the named substrings are set, the
557     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
558     empty string.
559    
560     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
561     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
562     because the ] is interpreted as the first data character and the
563     terminating ] is not found. PCRE has been made compatible with Perl in this
564     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
565     cause memory overwriting.
566    
567 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
568     string has been matched (to stop an infinite loop). It was not recognizing
569 ph10 208 a conditional subpattern that could match an empty string if that
570 ph10 206 subpattern was within another subpattern. For example, it looped when
571 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
572 ph10 206 condition was not nested. This bug has been fixed.
573 ph10 208
574 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
575     past the start of the subject in the presence of bytes with the top bit
576     set, for example "\x8aBCD".
577 ph10 211
578 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
579     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
580 ph10 200
581 ph10 211 14. Optimized (?!) to (*FAIL).
582 ph10 202
583 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
584     This restricts code points to be within the range 0 to 0x10FFFF, excluding
585     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
586     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
587     does: it's just the validity check that is more restrictive.
588 ph10 220
589     16. Inserted checks for integer overflows during escape sequence (backslash)
590     processing, and also fixed erroneous offset values for syntax errors during
591     backslash processing.
592    
593 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
594 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
595    
596 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
597     caused an overrun.
598 ph10 220
599     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
600     something other than just ASCII characters) inside a group that had an
601     unlimited repeat caused a loop at compile time (while checking to see
602     whether the group could match an empty string).
603    
604 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
605     [\P{Any}] did so. (Error in the code for printing property names.)
606 ph10 210
607 ph10 220 21. An orphan \E inside a character class could cause a crash.
608    
609     22. A repeated capturing bracket such as (A)? could cause a wild memory
610 ph10 218 reference during compilation.
611 ph10 220
612     23. There are several functions in pcre_compile() that scan along a compiled
613     expression for various reasons (e.g. to see if it's fixed length for look
614 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
615 ph10 220 present in the pattern. These operators have additional parameters compared
616     with \d, etc, and these were not being taken into account when moving along
617 ph10 218 the compiled data. Specifically:
618 ph10 220
619     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
620     length.
621    
622     (b) An item such as \pL+ within a repeated group could cause crashes or
623 ph10 218 loops.
624 ph10 220
625 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
626 ph10 220 "reference to non-existent subpattern" error.
627    
628 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
629    
630 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
631 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
632 ph10 211
633 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
634 ph10 218
635 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
636 ph10 223 character were causing crashes (broken optimization).
637 ph10 227
638 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
639 ph10 227 \p or \P) caused a compile-time loop.
640    
641 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
642     break. For example, the unstudied pattern [\r\n]A does not match the string
643     "\r\nA" because change 7.0/46 below moves the current point on by two
644     characters after failing to match at the start. However, the pattern \nA
645 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
646     the same is true. There doesn't seem any very clean way out of this, but
647     what I have chosen to do makes the common cases work: PCRE now takes note
648     of whether there can be an explicit match for \r or \n anywhere in the
649     pattern, and if so, 7.0/46 no longer applies. As part of this change,
650     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
651     pattern has explicit CR or LF references.
652 ph10 222
653 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
654 ph10 223
655 ph10 227
656 ph10 189 Version 7.2 19-Jun-07
657     ---------------------
658    
659 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
660     which is apparently normally available under Windows.
661 ph10 159
662     2. Re-jig the pcregrep tests with different newline settings in an attempt
663     to make them independent of the local environment's newline setting.
664 ph10 157
665 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
666 ph10 165
667 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
668     was not 2, because the output contained actual offsets. The recent new
669 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
670     usable with all link sizes.
671    
672 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
673     stack recursion. This gives a massive performance boost under BSD, but just
674 ph10 165 a small improvement under Linux. However, it saves one field in the frame
675 ph10 164 in all cases.
676 ph10 172
677 ph10 166 6. Added more features from the forthcoming Perl 5.10:
678 ph10 172
679 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
680     recursion call. It refers to the nth most recently opened parentheses.
681 ph10 172
682 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
683 ph10 172 to be opened parentheses.
684    
685     (c) Conditions that refer to capturing parentheses can be specified
686 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
687 ph10 172
688 ph10 168 (d) \K resets the start of the current match so that everything before
689 ph10 172 is not part of it.
690    
691 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
692 ph10 172
693 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
694 ph10 172 reference syntax.
695 ph10 182
696 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
697 ph10 182 alternative starts with the same number.
698 ph10 172
699 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
700    
701 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
702     PCRE_INFO_JCHANGED.
703    
704     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
705     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
706 ph10 170 for detecting groups that can match an empty string.
707 ph10 159
708 ph10 172 9. A pattern with a very large number of alternatives (more than several
709     hundred) was running out of internal workspace during the pre-compile
710     phase, where pcre_compile() figures out how much memory will be needed. A
711     bit of new cunning has reduced the workspace needed for groups with
712     alternatives. The 1000-alternative test pattern now uses 12 bytes of
713     workspace instead of running out of the 4096 that are available.
714 ph10 182
715 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
716 ph10 172
717 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
718     The report of the bug said:
719 ph10 182
720 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
721     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
722 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
723 ph10 185
724 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
725 ph10 185 it matched the wrong number of bytes.
726 ph10 172
727 ph10 179
728 ph10 155 Version 7.1 24-Apr-07
729 ph10 98 ---------------------
730    
731 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
732 ph10 122 that is more "standard", making use of automake and other Autotools. There
733 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
734     on this.
735 ph10 111
736     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
737     for recursive directory scanning broke on some systems because the files
738     are not scanned in any specific order and on different systems the order
739     was different. A call to "sort" has been inserted into RunGrepTest for the
740     approprate test as a short-term fix. In the longer term there may be an
741 ph10 100 alternative.
742 ph10 111
743 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
744 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
745     people do their own conversions for various reasons). The problems
746     concerned the use of low-level troff macros .br and .in. I have therefore
747     removed all such uses from the man pages (some were redundant, some could
748 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
749     HTML has been updated to handle .nf/.fi and to complain if it encounters
750     .br or .in.
751 ph10 111
752 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
753 ph10 123 arranged for config.h to be included in the distribution, with the name
754 ph10 111 config.h.generic, for the benefit of those who have to compile without
755     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
756    
757     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
758     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
759 ph10 127 makevp.bat for the current PCRE, using the additional files
760 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
761 ph10 111
762     6. A Windows user reported a minor discrepancy with test 2, which turned out
763     to be caused by a trailing space on an input line that had got lost in his
764 ph10 102 copy. The trailing space was an accident, so I've just removed it.
765 ph10 111
766 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
767 ph10 111 that is needed.
768    
769 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
770     as "const" (a) because they are and (b) because it helps the PHP
771     maintainers who have recently made a script to detect big data structures
772 ph10 111 in the php code that should be moved to the .rodata section. I remembered
773     to update Builducptable as well, so it won't revert if ucptable.h is ever
774 ph10 105 re-created.
775 ph10 111
776     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
777 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
778 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
779     support is not required. This saves 1.5-2K of code, which is important in
780 ph10 107 some applications.
781 ph10 111
782 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
783 ph10 111 so as not to refer to the tables, even though these functions will never be
784     called when UTF-8 support is disabled. Otherwise there are problems with a
785     shared library.
786    
787 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
788    
789     (a) It was defining its arguments as char * instead of void *.
790    
791 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
792     a long time ago when I wrote it, but is no longer the case.
793    
794 ph10 118 The emulated memove() is provided for those environments that have neither
795 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
796 ph10 118 is clearly not the case, as these two bugs were recently reported.
797 ph10 123
798 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
799 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
800     pages, and it removes trailing spaces from listed files. It also creates
801     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
802     case, it wraps all the #defines with #ifndefs. This script should be run
803 ph10 111 before "make dist".
804 ph10 123
805 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
806     with Unicode property support.
807 ph10 123
808     (a) For a maximizing quantifier, if the two different cases of the
809     character were of different lengths in their UTF-8 codings (there are
810     some cases like this - I found 11), and the matching function had to
811 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
812     were both the same length.
813 ph10 123
814     (b) When PCRE was configured to use the heap rather than the stack for
815     recursion during matching, it was not correctly preserving the data for
816     the other case of a UTF-8 character when checking ahead for a match
817     while processing a minimizing repeat. If the check also involved
818 ph10 115 matching a wide character, but failed, corruption could cause an
819     erroneous result when trying to check for a repeat of the original
820     character.
821 ph10 123
822 ph10 116 13. Some tidying changes to the testing mechanism:
823 ph10 98
824 ph10 116 (a) The RunTest script now detects the internal link size and whether there
825     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
826 ph10 123 values substituted by "configure". (The RunGrepTest script already did
827     this for UTF-8.) The configure.ac script no longer substitutes the
828     relevant variables.
829    
830 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
831     with length and offset values. This means that the output is different
832     for different internal link sizes. Test 2 is skipped for link sizes
833     other than 2 because of this, bypassing the problem. Unfortunately,
834     there was also a test in test 3 (the locale tests) that used /B and
835 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
836     I have added a new /Z option to pcretest that replaces the length and
837     offset values with spaces. This is now used to make test 3 independent
838 ph10 122 of link size. (Test 2 will be tidied up later.)
839 ph10 123
840     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
841 ph10 122 segmentation fault instead of returning the appropriate error message.
842 ph10 134
843 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
844 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
845     This doesn't seem right; it now treats the CRLF combination as the line
846     ending, and so does not match in that case. It's only a pattern such as ^$
847     that would hit this one: something like ^ABC$ would have failed after \r
848     and then tried again after \r\n.
849    
850 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
851 ph10 134 in an attempt to make files that differ only in their line terminators
852     compare equal. This works on Linux.
853 ph10 142
854 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
855     as it exited. This is now fixed, thanks to valgrind.
856 ph10 142
857 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
858 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
859     was because its rules for how to advance for /g after matching an empty
860 ph10 143 string at the end of a line did not allow for this case. They now check for
861     it specially.
862 ph10 150
863     20. pcretest is supposed to handle patterns and data of any length, by
864     extending its buffers when necessary. It was getting this wrong when the
865 ph10 147 buffer for a data line had to be extended.
866 ph10 150
867 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
868 ph10 150 CRLF as a newline sequence.
869 ph10 152
870 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
871 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
872     I have nevertheless tidied it up.
873 ph10 111
874 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
875 ph10 123
876 ph10 153 24. Added a man page for pcre-config.
877 ph10 152
878 ph10 153
879 nigel 93 Version 7.0 19-Dec-06
880     ---------------------
881    
882     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
883     moving to gcc 4.1.1.
884    
885     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
886     sys/time.h, which is documented as needed for this function. It doesn't
887     seem to matter on Linux, but it showed up on some releases of OS X.
888    
889     3. It seems that there are systems where bytes whose values are greater than
890     127 match isprint() in the "C" locale. The "C" locale should be the
891     default when a C program starts up. In most systems, only ASCII printing
892     characters match isprint(). This difference caused the output from pcretest
893     to vary, making some of the tests fail. I have changed pcretest so that:
894    
895     (a) When it is outputting text in the compiled version of a pattern, bytes
896     other than 32-126 are always shown as hex escapes.
897    
898     (b) When it is outputting text that is a matched part of a subject string,
899     it does the same, unless a different locale has been set for the match
900     (using the /L modifier). In this case, it uses isprint() to decide.
901    
902     4. Fixed a major bug that caused incorrect computation of the amount of memory
903     required for a compiled pattern when options that changed within the
904     pattern affected the logic of the preliminary scan that determines the
905     length. The relevant options are -x, and -i in UTF-8 mode. The result was
906     that the computed length was too small. The symptoms of this bug were
907     either the PCRE error "internal error: code overflow" from pcre_compile(),
908     or a glibc crash with a message such as "pcretest: free(): invalid next
909     size (fast)". Examples of patterns that provoked this bug (shown in
910     pcretest format) are:
911    
912     /(?-x: )/x
913     /(?x)(?-x: \s*#\s*)/
914     /((?i)[\x{c0}])/8
915     /(?i:[\x{c0}])/8
916    
917     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
918     is now done differently.
919    
920     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
921     wrapper classes; (b) implement a new function in the C++ scanner that is
922     more efficient than the old way of doing things because it avoids levels of
923     recursion in the regex matching; (c) add a paragraph to the documentation
924     for the FullMatch() function.
925    
926     6. The escape sequence \n was being treated as whatever was defined as
927     "newline". Not only was this contrary to the documentation, which states
928     that \n is character 10 (hex 0A), but it also went horribly wrong when
929     "newline" was defined as CRLF. This has been fixed.
930    
931     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
932     was being set to -1 for the "end of line" case (supposedly a value that no
933     character can have). Though this value is never used (the check for end of
934     line is "zero bytes in current character"), it caused compiler complaints.
935     I've changed it to 0xffffffff.
936    
937     8. In pcre_version.c, the version string was being built by a sequence of
938     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
939     string (as it is for production releases) called a macro with an empty
940     argument. The C standard says the result of this is undefined. The gcc
941     compiler treats it as an empty string (which was what was wanted) but it is
942     reported that Visual C gives an error. The source has been hacked around to
943     avoid this problem.
944    
945     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
946     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
947     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
948     of them did).
949    
950     10. Originally, pcretest opened its input and output without "b"; then I was
951     told that "b" was needed in some environments, so it was added for release
952     5.0 to both the input and output. (It makes no difference on Unix-like
953     systems.) Later I was told that it is wrong for the input on Windows. I've
954     now abstracted the modes into two macros, to make it easier to fiddle with
955     them, and removed "b" from the input mode under Windows.
956    
957     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
958    
959     12. Added -help and --help to pcretest as an official way of being reminded
960     of the options.
961    
962     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
963     and pcrecpp.cc because they annoy compilers at high warning levels.
964    
965     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
966    
967     15. Fixed an occurrence of == in configure.ac that should have been = (shell
968     scripts are not C programs :-) and which was not noticed because it works
969     on Linux.
970    
971     16. pcretest is supposed to handle any length of pattern and data line (as one
972     line or as a continued sequence of lines) by extending its input buffer if
973     necessary. This feature was broken for very long pattern lines, leading to
974     a string of junk being passed to pcre_compile() if the pattern was longer
975     than about 50K.
976    
977     17. I have done a major re-factoring of the way pcre_compile() computes the
978     amount of memory needed for a compiled pattern. Previously, there was code
979     that made a preliminary scan of the pattern in order to do this. That was
980     OK when PCRE was new, but as the facilities have expanded, it has become
981     harder and harder to keep it in step with the real compile phase, and there
982     have been a number of bugs (see for example, 4 above). I have now found a
983     cunning way of running the real compile function in a "fake" mode that
984     enables it to compute how much memory it would need, while actually only
985     ever using a few hundred bytes of working memory and without too many
986     tests of the mode. This should make future maintenance and development
987     easier. A side effect of this work is that the limit of 200 on the nesting
988     depth of parentheses has been removed (though this was never a serious
989     limitation, I suspect). However, there is a downside: pcre_compile() now
990     runs more slowly than before (30% or more, depending on the pattern). I
991     hope this isn't a big issue. There is no effect on runtime performance.
992    
993     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
994     newline (only possible for the last line of a file) and it was a
995     pattern that set a locale (followed by /Lsomething), pcretest crashed.
996    
997     19. Added additional timing features to pcretest. (1) The -tm option now times
998     matching only, not compiling. (2) Both -t and -tm can be followed, as a
999     separate command line item, by a number that specifies the number of
1000     repeats to use when timing. The default is 50000; this gives better
1001     precision, but takes uncomfortably long for very large patterns.
1002    
1003     20. Extended pcre_study() to be more clever in cases where a branch of a
1004     subpattern has no definite first character. For example, (a*|b*)[cd] would
1005     previously give no result from pcre_study(). Now it recognizes that the
1006     first character must be a, b, c, or d.
1007    
1008     21. There was an incorrect error "recursive call could loop indefinitely" if
1009     a subpattern (or the entire pattern) that was being tested for matching an
1010     empty string contained only one non-empty item after a nested subpattern.
1011     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1012     incorrectly, because the \d was being skipped in the check.
1013    
1014     22. The pcretest program now has a new pattern option /B and a command line
1015     option -b, which is equivalent to adding /B to every pattern. This causes
1016     it to show the compiled bytecode, without the additional information that
1017     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1018     is the same as /B/I).
1019    
1020     23. A new optimization is now able automatically to treat some sequences such
1021     as a*b as a*+b. More specifically, if something simple (such as a character
1022     or a simple class like \d) has an unlimited quantifier, and is followed by
1023     something that cannot possibly match the quantified thing, the quantifier
1024     is automatically "possessified".
1025    
1026     24. A recursive reference to a subpattern whose number was greater than 39
1027     went wrong under certain circumstances in UTF-8 mode. This bug could also
1028     have affected the operation of pcre_study().
1029    
1030     25. Realized that a little bit of performance could be had by replacing
1031     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1032    
1033     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1034    
1035     27. Possessive quantifiers such as a++ were previously implemented by turning
1036     them into atomic groups such as ($>a+). Now they have their own opcodes,
1037     which improves performance. This includes the automatically created ones
1038     from 23 above.
1039    
1040     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1041     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1042     the first matched character to be a colon. This applied both to named and
1043     numbered groups.
1044    
1045     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1046    
1047     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1048     building PCRE on Windows easier, so I have included it in the distribution.
1049    
1050     31. There is now a check in pcretest against a ridiculously large number being
1051     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1052     loop, the loop is abandoned.
1053    
1054     32. Forward references to subpatterns in conditions such as (?(2)...) where
1055     subpattern 2 is defined later cause pcre_compile() to search forwards in
1056     the pattern for the relevant set of parentheses. This search went wrong
1057     when there were unescaped parentheses in a character class, parentheses
1058     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1059    
1060     33. "Subroutine" calls and backreferences were previously restricted to
1061     referencing subpatterns earlier in the regex. This restriction has now
1062     been removed.
1063    
1064     34. Added a number of extra features that are going to be in Perl 5.10. On the
1065     whole, these are just syntactic alternatives for features that PCRE had
1066     previously implemented using the Python syntax or my own invention. The
1067     other formats are all retained for compatibility.
1068    
1069     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1070     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1071     also .NET compatible.
1072    
1073     (b) A recursion or subroutine call to a named group can now be defined as
1074     (?&name) as well as (?P>name).
1075    
1076     (c) A backreference to a named group can now be defined as \k<name> or
1077     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1078     5.10, are also .NET compatible.
1079    
1080     (d) A conditional reference to a named group can now use the syntax
1081     (?(<name>) or (?('name') as well as (?(name).
1082    
1083     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1084     groups (named and numbered) that are never evaluated inline, but can be
1085     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1086     is always false. There may be only one alternative in such a group.
1087    
1088     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1089     as the simple (?(R). The condition is true only if the most recent
1090     recursion is that of the given number or name. It does not search out
1091     through the entire recursion stack.
1092    
1093     (g) The escape \gN or \g{N} has been added, where N is a positive or
1094     negative number, specifying an absolute or relative reference.
1095    
1096     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1097     some "unreachable code" warnings.
1098    
1099     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1100     things, this adds five new scripts.
1101    
1102     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1103     There were also incompatibilities regarding the handling of \Q..\E inside
1104     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1105     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1106    
1107     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1108     matches an empty string, and forcibly breaks the loop. There were bugs in
1109     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1110     against aaaa the result was just "a" rather than "aaaa", for example. Two
1111     separate and independent bugs (that affected different cases) have been
1112     fixed.
1113    
1114     39. Refactored the code to abolish the use of different opcodes for small
1115     capturing bracket numbers. This is a tidy that I avoided doing when I
1116     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1117     The new approach is not only tidier, it makes it possible to reduce the
1118     memory needed to fix the previous bug (38).
1119    
1120     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1121     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1122     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1123     mode.
1124    
1125     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1126     report.
1127    
1128     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1129     copy construction and assignment in the C++ wrapper.
1130    
1131     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1132     couple of bugs that could have given wrong results in the "--newline=crlf"
1133     case.
1134    
1135     44. Added a number of casts and did some reorganization of signed/unsigned int
1136     variables following suggestions from Dair Grant. Also renamed the variable
1137     "this" as "item" because it is a C++ keyword.
1138    
1139     45. Arranged for dftables to add
1140    
1141     #include "pcre_internal.h"
1142    
1143     to pcre_chartables.c because without it, gcc 4.x may remove the array
1144     definition from the final binary if PCRE is built into a static library and
1145     dead code stripping is activated.
1146    
1147     46. For an unanchored pattern, if a match attempt fails at the start of a
1148     newline sequence, and the newline setting is CRLF or ANY, and the next two
1149     characters are CRLF, advance by two characters instead of one.
1150    
1151    
1152 nigel 91 Version 6.7 04-Jul-06
1153     ---------------------
1154    
1155     1. In order to handle tests when input lines are enormously long, pcretest has
1156     been re-factored so that it automatically extends its buffers when
1157     necessary. The code is crude, but this _is_ just a test program. The
1158     default size has been increased from 32K to 50K.
1159    
1160     2. The code in pcre_study() was using the value of the re argument before
1161     testing it for NULL. (Of course, in any sensible call of the function, it
1162     won't be NULL.)
1163    
1164     3. The memmove() emulation function in pcre_internal.h, which is used on
1165     systems that lack both memmove() and bcopy() - that is, hardly ever -
1166     was missing a "static" storage class specifier.
1167    
1168     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1169     containing an extended class (one that cannot be represented by a bitmap
1170     because it contains high-valued characters or Unicode property items, e.g.
1171     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1172     pattern, but PCRE should not loop if you do not (it no longer does).
1173     [Detail: two cases were found: (a) a repeated subpattern containing an
1174     extended class; (b) a recursive reference to a subpattern that followed a
1175     previous extended class. It wasn't skipping over the extended class
1176     correctly when UTF-8 mode was not set.]
1177    
1178     5. A negated single-character class was not being recognized as fixed-length
1179     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1180     compile error "lookbehind assertion is not fixed length".
1181    
1182     6. The RunPerlTest auxiliary script was showing an unexpected difference
1183     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1184     write a Perl script that can interpret lines of an input file either as
1185     byte characters or as UTF-8, which is what "perltest" was being required to
1186     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1187     can't do is switch easily at run time between having the "use utf8;" pragma
1188     or not. In the end, I fudged it by using the RunPerlTest script to insert
1189     "use utf8;" explicitly for the UTF-8 tests.
1190    
1191     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1192     the end of the subject string, contrary to the documentation and to what
1193     Perl does. This was true of both matching functions. Now it matches only at
1194     the start of the subject and immediately after *internal* newlines.
1195    
1196     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1197     a pointer to an int instead of a pointer to an unsigned long int. This
1198     caused problems on 64-bit systems.
1199    
1200     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1201     instance of the 'standard' template library not being so standard".
1202    
1203     10. There was no check on the number of named subpatterns nor the maximum
1204     length of a subpattern name. The product of these values is used to compute
1205     the size of the memory block for a compiled pattern. By supplying a very
1206     long subpattern name and a large number of named subpatterns, the size
1207     computation could be caused to overflow. This is now prevented by limiting
1208     the length of names to 32 characters, and the number of named subpatterns
1209     to 10,000.
1210    
1211     11. Subpatterns that are repeated with specific counts have to be replicated in
1212     the compiled pattern. The size of memory for this was computed from the
1213     length of the subpattern and the repeat count. The latter is limited to
1214     65535, but there was no limit on the former, meaning that integer overflow
1215     could in principle occur. The compiled length of a repeated subpattern is
1216     now limited to 30,000 bytes in order to prevent this.
1217    
1218     12. Added the optional facility to have named substrings with the same name.
1219    
1220     13. Added the ability to use a named substring as a condition, using the
1221     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1222     are numbers (not recommended). Forward references are permitted.
1223    
1224     14. Added forward references in named backreferences (if you see what I mean).
1225    
1226     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1227     pattern could run off the end of the subject. For example, the pattern
1228     "(?s)(.{1,5})"8 did this with the subject "ab".
1229    
1230     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1231     PCRE_CASELESS was set when matching characters that were quantified with ?
1232     or *.
1233    
1234     17. A character class other than a single negated character that had a minimum
1235     but no maximum quantifier - for example [ab]{6,} - was not handled
1236     correctly by pce_dfa_exec(). It would match only one character.
1237    
1238     18. A valid (though odd) pattern that looked like a POSIX character
1239     class but used an invalid character after [ (for example [[,abc,]]) caused
1240     pcre_compile() to give the error "Failed: internal error: code overflow" or
1241     in some cases to crash with a glibc free() error. This could even happen if
1242     the pattern terminated after [[ but there just happened to be a sequence of
1243     letters, a binary zero, and a closing ] in the memory that followed.
1244    
1245     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1246     over the years. Originally (before any Unicode support), just the bottom 8
1247     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1248     output from "man perlunicode" includes this:
1249    
1250     The regular expression compiler produces polymorphic opcodes. That
1251     is, the pattern adapts to the data and automatically switches to
1252     the Unicode character scheme when presented with Unicode data--or
1253     instead uses a traditional byte scheme when presented with byte
1254     data.
1255    
1256     Sadly, a wide octal escape does not cause a switch, and in a string with
1257     no other multibyte characters, these octal escapes are treated as before.
1258     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1259     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1260     Unicode string.
1261    
1262     I have not perpetrated such confusion in PCRE. Up till now, it took just
1263     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1264     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1265     translate to the appropriate multibyte character.
1266    
1267     29. Applied some refactoring to reduce the number of warnings from Microsoft
1268     and Borland compilers. This has included removing the fudge introduced
1269     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1270     a warning about an unused variable.
1271    
1272     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1273     characters since release 4.0, because Perl (from release 5.004) does not.
1274     [Or at least, is documented not to: some releases seem to be in conflict
1275     with the documentation.] However, when a pattern was studied with
1276     pcre_study() and all its branches started with \s, PCRE still included VT
1277     as a possible starting character. Of course, this did no harm; it just
1278     caused an unnecessary match attempt.
1279    
1280     22. Removed a now-redundant internal flag bit that recorded the fact that case
1281     dependency changed within the pattern. This was once needed for "required
1282     byte" processing, but is no longer used. This recovers a now-scarce options
1283     bit. Also moved the least significant internal flag bit to the most-
1284     significant bit of the word, which was not previously used (hangover from
1285     the days when it was an int rather than a uint) to free up another bit for
1286     the future.
1287    
1288     23. Added support for CRLF line endings as well as CR and LF. As well as the
1289     default being selectable at build time, it can now be changed at runtime
1290     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1291     specify that it is scanning data with non-default line endings.
1292    
1293     24. Changed the definition of CXXLINK to make it agree with the definition of
1294     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1295    
1296     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1297     recursions. This makes a big different to stack usage for some patterns.
1298    
1299     26. If a subpattern containing a named recursion or subroutine reference such
1300     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1301     the space required for the compiled pattern went wrong and gave too small a
1302     value. Depending on the environment, this could lead to "Failed: internal
1303     error: code overflow at offset 49" or "glibc detected double free or
1304     corruption" errors.
1305    
1306     27. Applied patches from Google (a) to support the new newline modes and (b) to
1307     advance over multibyte UTF-8 characters in GlobalReplace.
1308    
1309     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1310     difference for some implementation of PCRE in some Windows version.
1311    
1312     29. Added some extra testing facilities to pcretest:
1313    
1314     \q<number> in a data line sets the "match limit" value
1315     \Q<number> in a data line sets the "match recursion limt" value
1316     -S <number> sets the stack size, where <number> is in megabytes
1317    
1318     The -S option isn't available for Windows.
1319    
1320    
1321 nigel 89 Version 6.6 06-Feb-06
1322     ---------------------
1323    
1324     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1325     in pcreposix.h. I have copied the definition from pcre.h.
1326    
1327     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1328     because pcre.h is no longer a built file.
1329    
1330     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1331     not normally included in the compiled code.
1332    
1333    
1334 nigel 87 Version 6.5 01-Feb-06
1335     ---------------------
1336    
1337     1. When using the partial match feature with pcre_dfa_exec(), it was not
1338     anchoring the second and subsequent partial matches at the new starting
1339     point. This could lead to incorrect results. For example, with the pattern
1340     /1234/, partially matching against "123" and then "a4" gave a match.
1341    
1342     2. Changes to pcregrep:
1343    
1344     (a) All non-match returns from pcre_exec() were being treated as failures
1345     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1346     error message is output. Some extra information is given for the
1347     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1348     probably the only errors that are likely to be caused by users (by
1349     specifying a regex that has nested indefinite repeats, for instance).
1350     If there are more than 20 of these errors, pcregrep is abandoned.
1351    
1352     (b) A binary zero was treated as data while matching, but terminated the
1353     output line if it was written out. This has been fixed: binary zeroes
1354     are now no different to any other data bytes.
1355    
1356     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1357     used to set a locale for matching. The --locale=xxxx long option has
1358     been added (no short equivalent) to specify a locale explicitly on the
1359     pcregrep command, overriding the environment variables.
1360    
1361     (d) When -B was used with -n, some line numbers in the output were one less
1362     than they should have been.
1363    
1364     (e) Added the -o (--only-matching) option.
1365    
1366     (f) If -A or -C was used with -c (count only), some lines of context were
1367     accidentally printed for the final match.
1368    
1369     (g) Added the -H (--with-filename) option.
1370    
1371     (h) The combination of options -rh failed to suppress file names for files
1372     that were found from directory arguments.
1373    
1374     (i) Added the -D (--devices) and -d (--directories) options.
1375    
1376     (j) Added the -F (--fixed-strings) option.
1377    
1378     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1379    
1380     (l) Added the --colo(u)r option.
1381    
1382     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1383     is not present by default.
1384    
1385     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1386     items such as (?R) or (?1), when the recursion could match a number of
1387     alternatives. If it matched one of the alternatives, but subsequently,
1388     outside the recursion, there was a failure, the code tried to back up into
1389     the recursion. However, because of the way PCRE is implemented, this is not
1390     possible, and the result was an incorrect result from the match.
1391    
1392     In order to prevent this happening, the specification of recursion has
1393     been changed so that all such subpatterns are automatically treated as
1394     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1395    
1396     4. I had overlooked the fact that, in some locales, there are characters for
1397     which isalpha() is true but neither isupper() nor islower() are true. In
1398     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1399     and ordfeminine) are like this. This affected the treatment of \w and \W
1400     when they appeared in character classes, but not when they appeared outside
1401     a character class. The bit map for "word" characters is now created
1402     separately from the results of isalnum() instead of just taking it from the
1403     upper, lower, and digit maps. (Plus the underscore character, of course.)
1404    
1405     5. The above bug also affected the handling of POSIX character classes such as
1406     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1407     permanent tables. Instead, the bit maps for such a class were previously
1408     created as the appropriate unions of the upper, lower, and digit bitmaps.
1409     Now they are created by subtraction from the [[:word:]] class, which has
1410     its own bitmap.
1411    
1412     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1413     It is created by subtracting the vertical space characters (\x09, \x0a,
1414     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1415     subtraction was done in the overall bitmap for a character class, meaning
1416     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1417     be recognized. This bug has been fixed.
1418    
1419     7. Patches from the folks at Google:
1420    
1421     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1422     real life, but is still worth protecting against".
1423    
1424     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1425     regular expressions".
1426    
1427     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1428     have it.
1429    
1430     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1431     "configure" and the latter not, in order to fix a problem somebody had
1432     with compiling the Arg class on HP-UX.
1433    
1434     (e) Improve the error-handling of the C++ wrapper a little bit.
1435    
1436     (f) New tests for checking recursion limiting.
1437    
1438     8. The pcre_memmove() function, which is used only if the environment does not
1439     have a standard memmove() function (and is therefore rarely compiled),
1440     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1441     returning a result (though PCRE never actually uses the result).
1442    
1443     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1444     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1445     returned instead of calling malloc() with an overflowing number that would
1446     most likely cause subsequent chaos.
1447    
1448     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1449    
1450     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1451     with this option is matched, the nmatch and pmatch options of regexec() are
1452     ignored.
1453    
1454     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1455     provided in case anyone wants to the the POSIX interface with UTF-8
1456     strings.
1457    
1458     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1459     C++ linking (needed for some HP-UX environments).
1460    
1461     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1462     (unused parameter) and in the pcre_printint() function (omitted "default"
1463     switch label when the default is to do nothing).
1464    
1465     15. Added some code to make it possible, when PCRE is compiled as a C++
1466     library, to replace subject pointers for pcre_exec() with a smart pointer
1467     class, thus making it possible to process discontinuous strings.
1468    
1469     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1470     much the same function. They were added by different people who were trying
1471     to make PCRE easy to compile on non-Unix systems. It has been suggested
1472     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1473     for compiling on Windows systems. I have therefore replaced it with
1474     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1475     defaults to "extern" for C or "extern C" for C++, which works fine on
1476     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1477     SCOPE with something explicit in config.h. In addition:
1478    
1479     (a) pcreposix.h still had just "extern" instead of either of these macros;
1480     I have replaced it with PCRE_DATA_SCOPE.
1481    
1482     (b) Functions such as _pcre_xclass(), which are internal to the library,
1483     but external in the C sense, all had PCRE_EXPORT in their definitions.
1484     This is apparently wrong for the Windows case, so I have removed it.
1485     (It makes no difference on Unix-like systems.)
1486    
1487     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1488     of recursive calls to match(). This is different to MATCH_LIMIT because
1489     that limits the total number of calls to match(), not all of which increase
1490     the depth of recursion. Limiting the recursion depth limits the amount of
1491     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1492     when PCRE is compiled, and changed at run time. A patch from Google adds
1493     this functionality to the C++ interface.
1494    
1495     18. Changes to the handling of Unicode character properties:
1496    
1497     (a) Updated the table to Unicode 4.1.0.
1498    
1499     (b) Recognize characters that are not in the table as "Cn" (undefined).
1500    
1501     (c) I revised the way the table is implemented to a much improved format
1502     which includes recognition of ranges. It now supports the ranges that
1503     are defined in UnicodeData.txt, and it also amalgamates other
1504     characters into ranges. This has reduced the number of entries in the
1505     table from around 16,000 to around 3,000, thus reducing its size
1506     considerably. I realized I did not need to use a tree structure after
1507     all - a binary chop search is just as efficient. Having reduced the
1508     number of entries, I extended their size from 6 bytes to 8 bytes to
1509     allow for more data.
1510    
1511     (d) Added support for Unicode script names via properties such as \p{Han}.
1512    
1513     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1514     matching that character.
1515    
1516     20. When matching a repeated Unicode property with a minimum greater than zero,
1517     (for example \pL{2,}), PCRE could look past the end of the subject if it
1518     reached it while seeking the minimum number of characters. This could
1519     happen only if some of the characters were more than one byte long, because
1520     there is a check for at least the minimum number of bytes.
1521    
1522     21. Refactored the implementation of \p and \P so as to be more general, to
1523     allow for more different types of property in future. This has changed the
1524     compiled form incompatibly. Anybody with saved compiled patterns that use
1525     \p or \P will have to recompile them.
1526    
1527     22. Added "Any" and "L&" to the supported property types.
1528    
1529     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1530     but give a compile time error if the value is greater than 0xff.
1531    
1532     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1533     accidentally not being installed or uninstalled.
1534    
1535     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1536     made were to insert the current release number. This seemed silly, because
1537     it made things harder for people building PCRE on systems that don't run
1538     "configure". I have turned pcre.h into a distributed file, no longer built
1539     by "configure", with the version identification directly included. There is
1540     no longer a pcre.h.in file.
1541    
1542     However, this change necessitated a change to the pcre-config script as
1543     well. It is built from pcre-config.in, and one of the substitutions was the
1544     release number. I have updated configure.ac so that ./configure now finds
1545     the release number by grepping pcre.h.
1546    
1547     26. Added the ability to run the tests under valgrind.
1548    
1549    
1550 nigel 85 Version 6.4 05-Sep-05
1551     ---------------------
1552    
1553     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1554     "--" to be printed when multiple files were scanned, even when none of the
1555     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1556     consider it to be a bug, and have restored the previous behaviour.
1557    
1558     2. A couple of code tidies to get rid of compiler warnings.
1559    
1560     3. The pcretest program used to cheat by referring to symbols in the library
1561     whose names begin with _pcre_. These are internal symbols that are not
1562     really supposed to be visible externally, and in some environments it is
1563     possible to suppress them. The cheating is now confined to including
1564     certain files from the library's source, which is a bit cleaner.
1565    
1566     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1567     file's purpose clearer.
1568    
1569     5. Reorganized pcre_ucp_findchar().
1570    
1571    
1572 nigel 83 Version 6.3 15-Aug-05
1573     ---------------------
1574    
1575     1. The file libpcre.pc.in did not have general read permission in the tarball.
1576    
1577     2. There were some problems when building without C++ support:
1578    
1579     (a) If C++ support was not built, "make install" and "make test" still
1580     tried to test it.
1581    
1582     (b) There were problems when the value of CXX was explicitly set. Some
1583     changes have been made to try to fix these, and ...
1584    
1585     (c) --disable-cpp can now be used to explicitly disable C++ support.
1586    
1587     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1588     backslash in a target when C++ was disabled. This confuses some
1589     versions of "make", apparently. Using an intermediate variable solves
1590     this. (Same for CPP_LOBJ.)
1591    
1592     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1593     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1594     necessary on certain architectures.
1595    
1596     4. Added a setting of -export-symbols-regex to the link command to remove
1597     those symbols that are exported in the C sense, but actually are local
1598     within the library, and not documented. Their names all begin with
1599     "_pcre_". This is not a perfect job, because (a) we have to except some
1600     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1601     available (and never for static libraries). I have made a note to try to
1602     find a way round (a) in the future.
1603    
1604    
1605 nigel 81 Version 6.2 01-Aug-05
1606     ---------------------
1607    
1608     1. There was no test for integer overflow of quantifier values. A construction
1609     such as {1111111111111111} would give undefined results. What is worse, if
1610     a minimum quantifier for a parenthesized subpattern overflowed and became
1611     negative, the calculation of the memory size went wrong. This could have
1612     led to memory overwriting.
1613    
1614     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1615    
1616     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1617     operating environments where this matters.
1618    
1619     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1620     PCRE options from within the C++ wrapper.
1621    
1622     5. Named capturing subpatterns were not being correctly counted when a pattern
1623     was compiled. This caused two problems: (a) If there were more than 100
1624     such subpatterns, the calculation of the memory needed for the whole
1625     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1626     back references of the form \12, where the number was greater than 9, were
1627     not recognized as back references, even though there were sufficient
1628     previous subpatterns.
1629    
1630     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1631     versions of gcc, e.g. 2.95.4.
1632    
1633    
1634 nigel 79 Version 6.1 21-Jun-05
1635     ---------------------
1636    
1637     1. There was one reference to the variable "posix" in pcretest.c that was not
1638     surrounded by "#if !defined NOPOSIX".
1639    
1640     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1641     the cross-check on the old pcre_info() function, for the benefit of the
1642     cut-down version of PCRE that is currently imported into Exim.
1643    
1644     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1645     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1646     patterns that start (?i) but I don't think that matters. The use of (?i) is
1647     just an example; this all applies to the other options as well.
1648    
1649     4. Since libtool seems to echo the compile commands it is issuing, the output
1650     from "make" can be reduced a bit by putting "@" in front of each libtool
1651     compile command.
1652    
1653     5. Patch from the folks at Google for configure.in to be a bit more thorough
1654     in checking for a suitable C++ installation before trying to compile the
1655     C++ stuff. This should fix a reported problem when a compiler was present,
1656     but no suitable headers.
1657    
1658     6. The man pages all had just "PCRE" as their title. I have changed them to
1659     be the relevant file name. I have also arranged that these names are
1660     retained in the file doc/pcre.txt, which is a concatenation in text format
1661     of all the man pages except the little individual ones for each function.
1662    
1663     7. The NON-UNIX-USE file had not been updated for the different set of source
1664     files that come with release 6. I also added a few comments about the C++
1665     wrapper.
1666    
1667    
1668 nigel 77 Version 6.0 07-Jun-05
1669     ---------------------
1670    
1671     1. Some minor internal re-organization to help with my DFA experiments.
1672    
1673     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1674     didn't matter for the library itself when fully configured, but did matter
1675     when compiling without UCP support, or within Exim, where the ucp files are
1676     not imported.
1677    
1678     3. Refactoring of the library code to split up the various functions into
1679     different source modules. The addition of the new DFA matching code (see
1680     below) to a single monolithic source would have made it really too
1681     unwieldy, quite apart from causing all the code to be include in a
1682     statically linked application, when only some functions are used. This is
1683     relevant even without the DFA addition now that patterns can be compiled in
1684     one application and matched in another.
1685    
1686     The downside of splitting up is that there have to be some external
1687     functions and data tables that are used internally in different modules of
1688     the library but which are not part of the API. These have all had their
1689     names changed to start with "_pcre_" so that they are unlikely to clash
1690     with other external names.
1691    
1692     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1693     a different (DFA) algorithm. Although it is slower than the original
1694     function, it does have some advantages for certain types of matching
1695     problem.
1696    
1697     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1698     including restarting after a partial match.
1699    
1700     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1701     defined when compiling for Windows was sent to me. I have put it into the
1702     code, though I have no means of testing or verifying it.
1703    
1704     7. Added the pcre_refcount() auxiliary function.
1705    
1706     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1707     match before or at the first newline in the subject string. In pcretest,
1708     the /f option on a pattern can be used to set this.
1709    
1710     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1711     would behave wrongly. This has been present in PCRE since release 4.0.
1712    
1713     10. A number of changes to the pcregrep command:
1714    
1715     (a) Refactored how -x works; insert ^(...)$ instead of setting
1716     PCRE_ANCHORED and checking the length, in preparation for adding
1717     something similar for -w.
1718    
1719     (b) Added the -w (match as a word) option.
1720    
1721     (c) Refactored the way lines are read and buffered so as to have more
1722     than one at a time available.
1723    
1724     (d) Implemented a pcregrep test script.
1725    
1726     (e) Added the -M (multiline match) option. This allows patterns to match
1727     over several lines of the subject. The buffering ensures that at least
1728     8K, or the rest of the document (whichever is the shorter) is available
1729     for matching (and similarly the previous 8K for lookbehind assertions).
1730    
1731     (f) Changed the --help output so that it now says
1732    
1733     -w, --word-regex(p)
1734    
1735     instead of two lines, one with "regex" and the other with "regexp"
1736     because that confused at least one person since the short forms are the
1737     same. (This required a bit of code, as the output is generated
1738     automatically from a table. It wasn't just a text change.)
1739    
1740     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1741     option but starts with a hyphen. Could be a pattern or a path name
1742     starting with a hyphen, for instance.
1743    
1744     (h) "-" can be given as a file name to represent stdin.
1745    
1746     (i) When file names are being printed, "(standard input)" is used for
1747     the standard input, for compatibility with GNU grep. Previously
1748     "<stdin>" was used.
1749    
1750     (j) The option --label=xxx can be used to supply a name to be used for
1751     stdin when file names are being printed. There is no short form.
1752    
1753     (k) Re-factored the options decoding logic because we are going to add
1754     two more options that take data. Such options can now be given in four
1755     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1756    
1757     (l) Added the -A, -B, and -C options for requesting that lines of context
1758     around matches be printed.
1759    
1760     (m) Added the -L option to print the names of files that do not contain
1761     any matching lines, that is, the complement of -l.
1762    
1763     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1764     continue to scan other files.
1765    
1766     (o) The -s option was incorrectly implemented. For compatibility with other
1767     greps, it now suppresses the error message for a non-existent or non-
1768     accessible file (but not the return code). There is a new option called
1769     -q that suppresses the output of matching lines, which was what -s was
1770     previously doing.
1771    
1772     (p) Added --include and --exclude options to specify files for inclusion
1773     and exclusion when recursing.
1774    
1775     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1776     Hopefully, it now does.
1777    
1778     12. Missing cast in pcre_study().
1779    
1780     13. Added an "uninstall" target to the makefile.
1781    
1782     14. Replaced "extern" in the function prototypes in Makefile.in with
1783     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1784     world, but is set differently for Windows.
1785    
1786     15. Added a second compiling function called pcre_compile2(). The only
1787     difference is that it has an extra argument, which is a pointer to an
1788     integer error code. When there is a compile-time failure, this is set
1789     non-zero, in addition to the error test pointer being set to point to an
1790     error message. The new argument may be NULL if no error number is required
1791     (but then you may as well call pcre_compile(), which is now just a
1792     wrapper). This facility is provided because some applications need a
1793     numeric error indication, but it has also enabled me to tidy up the way
1794     compile-time errors are handled in the POSIX wrapper.
1795    
1796     16. Added VPATH=.libs to the makefile; this should help when building with one
1797     prefix path and installing with another. (Or so I'm told by someone who
1798     knows more about this stuff than I do.)
1799    
1800     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1801     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1802     match everything, including newlines. This is not POSIX-compatible, but
1803     somebody wanted the feature. From pcretest it can be activated by using
1804     both the P and the s flags.
1805    
1806     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1807    
1808     19. libpcre.pc was being incorrectly installed as executable.
1809    
1810     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1811     it now also looks for '\r' so that it will work unmodified on Windows.
1812    
1813     21. Added Google's contributed C++ wrapper to the distribution.
1814    
1815     22. Added some untidy missing memory free() calls in pcretest, to keep
1816     Electric Fence happy when testing.
1817    
1818    
1819    
1820 nigel 75 Version 5.0 13-Sep-04
1821     ---------------------
1822    
1823     1. Internal change: literal characters are no longer packed up into items
1824     containing multiple characters in a single byte-string. Each character
1825     is now matched using a separate opcode. However, there may be more than one
1826     byte in the character in UTF-8 mode.
1827    
1828     2. The pcre_callout_block structure has two new fields: pattern_position and
1829     next_item_length. These contain the offset in the pattern to the next match
1830     item, and its length, respectively.
1831    
1832     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1833     insertion of callouts before each pattern item. Added the /C option to
1834     pcretest to make use of this.
1835    
1836     4. On the advice of a Windows user, the lines
1837    
1838     #if defined(_WIN32) || defined(WIN32)
1839     _setmode( _fileno( stdout ), 0x8000 );
1840     #endif /* defined(_WIN32) || defined(WIN32) */
1841    
1842     have been added to the source of pcretest. This apparently does useful
1843     magic in relation to line terminators.
1844    
1845     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1846     for the benefit of those environments where the "b" makes a difference.
1847    
1848     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1849     to know about it. I have put a hack into configure.in that adds in code
1850     to set GCC=yes if CC=icc. This seems to end up at a point in the
1851     generated configure script that is early enough to affect the setting of
1852     compiler options, which is what is needed, but I have no means of testing
1853     whether it really works. (The user who reported this had patched the
1854     generated configure script, which of course I cannot do.)
1855    
1856     LATER: After change 22 below (new libtool files), the configure script
1857     seems to know about icc (and also ecc). Therefore, I have commented out
1858     this hack in configure.in.
1859    
1860     7. Added support for pkg-config (2 patches were sent in).
1861    
1862     8. Negated POSIX character classes that used a combination of internal tables
1863     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1864     [[:^ascii]]. Typically, they would match almost any characters. The other
1865     POSIX classes were not broken in this way.
1866    
1867     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1868     to find the match, as PCRE was deluded into thinking that the match had to
1869     start at the start point or following a newline. The same bug applied to
1870     patterns with negative forward assertions or any backward assertions
1871     preceding ".*" at the start, unless the pattern required a fixed first
1872     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1873    
1874     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1875     starting at the last subject character, bytes beyond the end of the subject
1876     string were read.
1877    
1878     11. Renamed the variable "class" as "classbits" to make life easier for C++
1879     users. (Previously there was a macro definition, but it apparently wasn't
1880     enough.)
1881    
1882     12. Added the new field "tables" to the extra data so that tables can be passed
1883     in at exec time, or the internal tables can be re-selected. This allows
1884     a compiled regex to be saved and re-used at a later time by a different
1885     program that might have everything at different addresses.
1886    
1887     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1888     -R library as well as a -L library.
1889    
1890     14. The debugging options of pcretest (-d on the command line or D on a
1891     pattern) showed incorrect output for anything following an extended class
1892     that contained multibyte characters and which was followed by a quantifier.
1893    
1894     15. Added optional support for general category Unicode character properties
1895     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1896     support. It adds about 90K to the size of the library. The meanings of the
1897     inbuilt class escapes such as \d and \s have NOT been changed.
1898    
1899     16. Updated pcredemo.c to include calls to free() to release the memory for the
1900     compiled pattern.
1901    
1902     17. The generated file chartables.c was being created in the source directory
1903     instead of in the building directory. This caused the build to fail if the
1904     source directory was different from the building directory, and was
1905     read-only.
1906    
1907     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1908     file. No doubt somebody will tell me if they don't make sense... Also added
1909     Dan Mooney's comments about building on OpenVMS.
1910    
1911     19. Added support for partial matching via the PCRE_PARTIAL option for
1912     pcre_exec() and the \P data escape in pcretest.
1913    
1914     20. Extended pcretest with 3 new pattern features:
1915    
1916     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1917     write the compiled pattern to the file whose name is "rest-of-line".
1918     This is a straight binary dump of the data, with the saved pointer to
1919     the character tables forced to be NULL. The study data, if any, is
1920     written too. After writing, pcretest reads a new pattern.
1921    
1922     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1923     compiled pattern from the given file. There must not be any
1924     occurrences of "<" in the file name (pretty unlikely); if there are,
1925     pcretest will instead treat the initial "<" as a pattern delimiter.
1926     After reading in the pattern, pcretest goes on to read data lines as
1927     usual.
1928    
1929     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1930     and 16-bit fields in a compiled pattern, to simulate a pattern that
1931     was compiled on a host of opposite endianness.
1932    
1933     21. The pcre-exec() function can now cope with patterns that were compiled on
1934     hosts of opposite endianness, with this restriction:
1935    
1936     As for any compiled expression that is saved and used later, the tables
1937     pointer field cannot be preserved; the extra_data field in the arguments
1938     to pcre_exec() should be used to pass in a tables address if a value
1939     other than the default internal tables were used at compile time.
1940    
1941     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1942     now diagnosed as an error. Previously, most of the time, a negative number
1943     would have been treated as zero, but if in addition "ovector" was passed as
1944     NULL, a crash could occur.
1945    
1946     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1947     new versions from the libtool 1.5 distribution (the last one is a copy of
1948     a file called libtool.m4). This seems to have fixed the need to patch
1949     "configure" to support Darwin 1.3 (which I used to do). However, I still
1950     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1951     workstation).
1952    
1953     24. Changed the PCRE licence to be the more standard "BSD" licence.
1954    
1955    
1956 nigel 73 Version 4.5 01-Dec-03
1957     ---------------------
1958    
1959     1. There has been some re-arrangement of the code for the match() function so
1960     that it can be compiled in a version that does not call itself recursively.
1961     Instead, it keeps those local variables that need separate instances for
1962     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1963     needs to "recurse". Keeping track of where control must go is done by means
1964     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1965     hide most of the details from the main code, and operates only if
1966     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1967     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1968     operating.
1969    
1970     To make it easier for callers to provide specially tailored get/free
1971     functions for this usage, two new functions, pcre_stack_malloc, and
1972     pcre_stack_free, are used. They are always called in strict stacking order,
1973     and the size of block requested is always the same.
1974    
1975     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1976     PCRE has been compiled to use the stack or the heap for recursion. The
1977     -C option of pcretest uses this to show which version is compiled.
1978    
1979     A new data escape \S, is added to pcretest; it causes the amounts of store
1980     obtained and freed by both kinds of malloc/free at match time to be added
1981     to the output.
1982    
1983     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1984     what's available on my current Linux desktop machine.
1985    
1986     3. When matching a UTF-8 string, the test for a valid string at the start has
1987     been extended. If start_offset is not zero, PCRE now checks that it points
1988     to a byte that is the start of a UTF-8 character. If not, it returns
1989     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1990     this is necessary because there may be backward assertions in the pattern.
1991     When matching the same subject several times, it may save resources to use
1992     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1993    
1994     4. The code for checking the validity of UTF-8 strings has been tightened so
1995     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1996     containing "overlong sequences".
1997    
1998     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1999     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2000     should have been "&", but it just so happened that all the cases this let
2001     through by mistake were picked up later in the function.
2002    
2003     6. I had used a variable called "isblank" - this is a C99 function, causing
2004     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2005    
2006     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2007     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2008     so the version is shown; (c) stop "make test" echoing "./RunTest".
2009    
2010     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2011    
2012     9. The prototype for memmove() for systems that don't have it was using
2013     size_t, but the inclusion of the header that defines size_t was later. I've
2014     moved the #includes for the C headers earlier to avoid this.
2015    
2016     10. Added some adjustments to the code to make it easier to compiler on certain
2017     special systems:
2018    
2019     (a) Some "const" qualifiers were missing.
2020     (b) Added the macro EXPORT before all exported functions; by default this
2021     is defined to be empty.
2022     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2023     that it reads its output file name as an argument instead of writing
2024     to the standard output and assuming this can be redirected.
2025    
2026     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2027     class containing characters with values greater than 255, PCRE compilation
2028     went into a loop.
2029    
2030     12. A recursive reference to a subpattern that was within another subpattern
2031     that had a minimum quantifier of zero caused PCRE to crash. For example,
2032     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2033     recursion. If the recursively-called subpattern itself had a zero repeat,
2034     that was OK.
2035    
2036     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2037     buffer into which it was copied (for escape processing) was still set at
2038     1024, so long lines caused crashes.
2039    
2040     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2041     "internal error: code overflow...". This applied to any character class
2042     that was followed by a possessive quantifier.
2043    
2044     15. Modified the Makefile to add libpcre.la as a prerequisite for
2045     libpcreposix.la because I was told this is needed for a parallel build to
2046     work.
2047    
2048     16. If a pattern that contained .* following optional items at the start was
2049     studied, the wrong optimizing data was generated, leading to matching
2050     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2051     matching string must start with a or b or c. The correct conclusion for
2052     this pattern is that a match can start with any character.
2053    
2054    
2055 nigel 71 Version 4.4 13-Aug-03
2056     ---------------------
2057    
2058     1. In UTF-8 mode, a character class containing characters with values between
2059     127 and 255 was not handled correctly if the compiled pattern was studied.
2060     In fixing this, I have also improved the studying algorithm for such
2061     classes (slightly).
2062    
2063     2. Three internal functions had redundant arguments passed to them. Removal
2064     might give a very teeny performance improvement.
2065    
2066     3. Documentation bug: the value of the capture_top field in a callout is *one
2067     more than* the number of the hightest numbered captured substring.
2068    
2069     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2070     in incorrectly linking with a previously installed version. They now link
2071     explicitly with libpcre.la.
2072    
2073     5. configure.in no longer needs to recognize Cygwin specially.
2074    
2075     6. A problem in pcre.in for Windows platforms is fixed.
2076    
2077     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2078     pcretest, it used to include the size of the study block as part of its
2079     output. Unfortunately, the structure contains a field that has a different
2080     size on different hardware architectures. This meant that the tests that
2081     showed this size failed. As the block is currently always of a fixed size,
2082     this information isn't actually particularly useful in pcretest output, so
2083     I have just removed it.
2084    
2085     8. Three pre-processor statements accidentally did not start in column 1.
2086     Sadly, there are *still* compilers around that complain, even though
2087     standard C has not required this for well over a decade. Sigh.
2088    
2089     9. In pcretest, the code for checking callouts passed small integers in the
2090     callout_data field, which is a void * field. However, some picky compilers
2091     complained about the casts involved for this on 64-bit systems. Now
2092     pcretest passes the address of the small integer instead, which should get
2093     rid of the warnings.
2094    
2095     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2096     both compile and run time, and gives an error if an invalid UTF-8 sequence
2097     is found. There is a option for disabling this check in cases where the
2098     string is known to be correct and/or the maximum performance is wanted.
2099    
2100     11. In response to a bug report, I changed one line in Makefile.in from
2101    
2102     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2103     to
2104     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2105    
2106     to look similar to other lines, but I have no way of telling whether this
2107     is the right thing to do, as I do not use Windows. No doubt I'll get told
2108     if it's wrong...
2109    
2110    
2111 nigel 69 Version 4.3 21-May-03
2112     ---------------------
2113    
2114     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2115     Makefile.
2116    
2117     2. Some refactoring to improve the quality of the code:
2118    
2119     (i) The utf8_table... variables are now declared "const".
2120    
2121     (ii) The code for \cx, which used the "case flipping" table to upper case
2122     lower case letters, now just substracts 32. This is ASCII-specific,
2123     but the whole concept of \cx is ASCII-specific, so it seems
2124     reasonable.
2125    
2126     (iii) PCRE was using its character types table to recognize decimal and
2127     hexadecimal digits in the pattern. This is silly, because it handles
2128     only 0-9, a-f, and A-F, but the character types table is locale-
2129     specific, which means strange things might happen. A private
2130     table is now used for this - though it costs 256 bytes, a table is
2131     much faster than multiple explicit tests. Of course, the standard
2132     character types table is still used for matching digits in subject
2133     strings against \d.
2134    
2135     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2136     ending in _t are). So I've renamed it as ESC_tee.
2137    
2138     3. The first argument for regexec() in the POSIX wrapper should have been
2139     defined as "const".
2140    
2141     4. Changed pcretest to use malloc() for its buffers so that they can be
2142     Electric Fenced for debugging.
2143    
2144     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2145     to read one or more bytes before the start of the subject string. Often this
2146     had no effect on PCRE's behaviour, but in some circumstances it could
2147     provoke a segmentation fault.
2148    
2149     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2150     to try to read one or more bytes before the start of the subject string.
2151    
2152     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2153     UTF-8 support could misbehave in various ways if the subject string
2154     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2155     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2156     back over UTF-8 characters.)
2157    
2158    
2159 nigel 67 Version 4.2 14-Apr-03
2160     ---------------------
2161    
2162     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2163    
2164     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2165     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2166     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2167     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2168     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2169     and BUILD_EXEEXT
2170     Note: automatic setting of the BUILD variables is not yet working
2171     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2172     compile-time but not at link-time
2173     [LINK]: use for linking executables only
2174     make different versions for Windows and non-Windows
2175     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2176     libraries
2177     [LINK_FOR_BUILD]: new variable
2178     [OBJEXT]: use throughout
2179     [EXEEXT]: use throughout
2180     <winshared>: new target
2181     <wininstall>: new target
2182     <dftables.o>: use native compiler
2183     <dftables>: use native linker
2184     <install>: handle Windows platform correctly
2185     <clean>: ditto
2186     <check>: ditto
2187     copy DLL to top builddir before testing
2188    
2189     As part of these changes, -no-undefined was removed again. This was reported
2190     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2191     in any case.
2192    
2193     3. Some tidies to get rid of compiler warnings:
2194    
2195     . In the match_data structure, match_limit was an unsigned long int, whereas
2196     match_call_count was an int. I've made them both unsigned long ints.
2197    
2198     . In pcretest the fact that a const uschar * doesn't automatically cast to
2199     a void * provoked a warning.
2200    
2201     . Turning on some more compiler warnings threw up some "shadow" variables
2202     and a few more missing casts.
2203    
2204     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2205     option, a class that contained a single character with a value between 128
2206     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2207    
2208     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2209     option, a class that contained several characters, but with at least one
2210     whose value was between 128 and 255 caused PCRE to crash.
2211    
2212    
2213 nigel 65 Version 4.1 12-Mar-03
2214     ---------------------
2215 nigel 63
2216 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2217     needed, and a string in dftables.c that was longer than standard compilers are
2218     required to support.
2219    
2220     2. Compiling with Sun's compiler found a few more places where the code could
2221     be tidied up in order to avoid warnings.
2222    
2223     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2224     first of these names is deprecated in the latest Autoconf in favour of the name
2225     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2226     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2227     analogy I have changed it to CFLAGS_FOR_BUILD.
2228    
2229     4. Added -no-undefined to the linking command in the Makefile, because this is
2230     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2231     linking step for the pcreposix library.
2232    
2233     5. PCRE was failing to diagnose the case of two named groups with the same
2234     name.
2235    
2236     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2237     literal character that is needed in the subject for a match, and scans along to
2238     ensure that it is present before embarking on the full matching process. This
2239     saves time in cases of nested unlimited repeats that are never going to match.
2240     Problem: the scan can take a lot of time if the subject is very long (e.g.
2241     megabytes), thus penalizing straightforward matches. It is now done only if the
2242     amount of subject to be scanned is less than 1000 bytes.
2243    
2244     7. A lesser problem with the same optimization is that it was recording the
2245     first character of an anchored pattern as "needed", thus provoking a search
2246     right along the subject, even when the first match of the pattern was going to
2247     fail. The "needed" character is now not set for anchored patterns, unless it
2248     follows something in the pattern that is of non-fixed length. Thus, it still
2249     fulfils its original purpose of finding quick non-matches in cases of nested
2250     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2251    
2252    
2253     Version 4.0 17-Feb-03
2254     ---------------------
2255    
2256 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2257     extended to the end of string, PCRE compiled incorrect data. This could lead to
2258     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2259    
2260     2. Moved to autoconf 2.53 and libtool 1.4.2.
2261    
2262     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2263     the special perltest8 script is no longer needed - all the tests can be run
2264     from a single perltest script.
2265    
2266     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2267     by \s. It has now been removed in PCRE. This means it isn't recognized as
2268     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2269     class [:space:] *does* include VT, thereby creating a mess.
2270    
2271     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2272     space and tab.
2273    
2274     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2275     its new features into the main test script, reducing the number of scripts.
2276    
2277     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2278     were backward compatible, and made the (?i) apply to the whole pattern, as if
2279     /i were given. Now it behaves more logically, and applies the option setting
2280     only to what follows. PCRE has been changed to follow suit. However, if it
2281     finds options settings right at the start of the pattern, it extracts them into
2282     the global options, as before. Thus, they show up in the info data.
2283    
2284     8. Added support for the \Q...\E escape sequence. Characters in between are
2285     treated as literals. This is slightly different from Perl in that $ and @ are
2286     also handled as literals inside the quotes. In Perl, they will cause variable
2287     interpolation. Note the following examples:
2288    
2289     Pattern PCRE matches Perl matches
2290    
2291     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2292     \Qabc\$xyz\E abc\$xyz abc\$xyz
2293     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2294    
2295     For compatibility with Perl, \Q...\E sequences are recognized inside character
2296     classes as well as outside them.
2297    
2298     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2299     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2300     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2301     signed/unsigned warnings.
2302    
2303     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2304     option for pcretest, so I've replaced it by a simple function that does just
2305     that job.
2306    
2307     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2308     "pcregrep -".
2309    
2310     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2311     Java package. This provides some syntactic sugar for simple cases of what my
2312     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2313     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2314     item, you can use this simplified notation. Note that only makes sense with
2315     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2316     greediness, whatever the setting of the PCRE_UNGREEDY option.
2317    
2318     13. A change of greediness default within a pattern was not taking effect at
2319     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2320     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2321     was abstracted outside.
2322    
2323     14. PCRE now supports the \G assertion. It is true when the current matching
2324     position is at the start point of the match. This differs from \A when the
2325     starting offset is non-zero. Used with the /g option of pcretest (or similar
2326     code), it works in the same way as it does for Perl's /g option. If all
2327     alternatives of a regex begin with \G, the expression is anchored to the start
2328     match position, and the "anchored" flag is set in the compiled expression.
2329    
2330     15. Some bugs concerning the handling of certain option changes within patterns
2331     have been fixed. These applied to options other than (?ims). For example,
2332     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2333     been the other way round. Some of this was related to change 7 above.
2334    
2335     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2336     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2337     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2338     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2339    
2340     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2341     mode. Unlike ".", it always matches newline, whatever the setting of
2342     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2343     assertions. Perl allows it, but it doesn't (in general) work because it can't
2344     calculate the length of the lookbehind. At least, that's the case for Perl
2345     5.8.0 - I've been told they are going to document that it doesn't work in
2346     future.
2347    
2348     18. Added an error diagnosis for escapes that PCRE does not support: these are
2349     \L, \l, \N, \P, \p, \U, \u, and \X.
2350    
2351     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2352     reading past the end of the pattern in cases such as /[abcd/.
2353    
2354     20. PCRE was getting more memory than necessary for patterns with classes that
2355     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2356    
2357     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2358     compiling PCRE for use with Virtual Pascal.
2359    
2360     22. Small fix to the Makefile to make it work properly if the build is done
2361     outside the source tree.
2362    
2363     23. Added a new extension: a condition to go with recursion. If a conditional
2364     subpattern starts with (?(R) the "true" branch is used if recursion has
2365     happened, whereas the "false" branch is used only at the top level.
2366    
2367     24. When there was a very long string of literal characters (over 255 bytes
2368     without UTF support, over 250 bytes with UTF support), the computation of how
2369     much memory was required could be incorrect, leading to segfaults or other
2370     strange effects.
2371    
2372     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2373     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2374     there was a subsequent back reference to those brackets. This meant that, for
2375     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2376     possible to check for precisely this case. All we can do is abandon the
2377     optimization if .* occurs inside capturing brackets when there are any back
2378     references whatsoever. (See below for a better fix that came later.)
2379    
2380     26. The handling of the optimization for finding the first character of a
2381     non-anchored pattern, and for finding a character that is required later in the
2382     match were failing in some cases. This didn't break the matching; it just
2383     failed to optimize when it could. The way this is done has been re-implemented.
2384    
2385     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2386    
2387     28. Added a new feature that provides some of the functionality that Perl
2388     provides with (?{...}). The facility is termed a "callout". The way it is done
2389     in PCRE is for the caller to provide an optional function, by setting
2390     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2391     global variable. By default it is unset, which disables all calling out. To get
2392     the function called, the regex must include (?C) at appropriate points. This
2393     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2394     This provides a means of identifying different callout points. When PCRE
2395     reaches such a point in the regex, if pcre_callout has been set, the external
2396     function is called. It is provided with data in a structure called
2397     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2398     matching continues; if it returns a non-zero value, the match at the current
2399     point fails. However, backtracking will occur if possible. [This was changed
2400     later and other features added - see item 49 below.]
2401    
2402     29. pcretest is upgraded to test the callout functionality. It provides a
2403     callout function that displays information. By default, it shows the start of
2404     the match and the current position in the text. There are some new data escapes
2405     to vary what happens:
2406    
2407     \C+ in addition, show current contents of captured substrings
2408     \C- do not supply a callout function
2409     \C!n return 1 when callout number n is reached
2410     \C!n!m return 1 when callout number n is reached for the mth time
2411    
2412     30. If pcregrep was called with the -l option and just a single file name, it
2413     output "<stdin>" if a match was found, instead of the file name.
2414    
2415     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2416     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2417     pcre_exec(). This saves a malloc/free per call. The default value of
2418     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2419     when configuring.
2420    
2421     32. The default maximum size of a compiled pattern is 64K. There have been a
2422     few cases of people hitting this limit. The code now uses macros to handle the
2423     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2424     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2425     configuring. Tests 2 and 5 work only with 2-byte links because they output
2426     debugging information about compiled patterns.
2427    
2428     33. Internal code re-arrangements:
2429    
2430     (a) Moved the debugging function for printing out a compiled regex into
2431     its own source file (printint.c) and used #include to pull it into
2432     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2433     separate copies.
2434    
2435     (b) Defined the list of op-code names for debugging as a macro in
2436     internal.h so that it is next to the definition of the opcodes.
2437    
2438     (c) Defined a table of op-code lengths for simpler skipping along compiled
2439     code. This is again a macro in internal.h so that it is next to the
2440     definition of the opcodes.
2441    
2442     34. Added support for recursive calls to individual subpatterns, along the
2443     lines of Robin Houston's patch (but implemented somewhat differently).
2444    
2445     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2446     allow it to read and process whole directories in Win32. This code was
2447     contributed by Lionel Fourquaux; it has not been tested by me.
2448    
2449     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2450     used to name a group. Names consist of alphanumerics and underscores, and must
2451     be unique. Back references use the syntax (?P=name) and recursive calls use
2452     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2453     numbers. The function pcre_fullinfo() can be used after compilation to extract
2454     a name/number map. There are three relevant calls:
2455    
2456     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2457     PCRE_INFO_NAMECOUNT yields the number of entries
2458     PCRE_INFO_NAMETABLE yields a pointer to the map.
2459    
2460     The map is a vector of fixed-size entries. The size of each entry depends on
2461     the length of the longest name used. The first two bytes of each entry are the
2462     group number, most significant byte first. There follows the corresponding
2463     name, zero terminated. The names are in alphabetical order.
2464    
2465     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2466     case instead of 255. Making it the same both with and without UTF-8 support
2467     means that the same test output works with both.
2468    
2469     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2470     calling malloc() with a zero argument.
2471    
2472     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2473     optimization. I've improved things by keeping a bitmap of backreferences with
2474     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2475     fact referenced, the optimization can be applied. It is unlikely that a
2476     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2477     the match to follow \n) will appear inside brackets with a number greater than
2478     31, but if it does, any back reference > 31 suppresses the optimization.
2479    
2480     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2481     of disabling numbered capturing parentheses. Any opening parenthesis that is
2482     not followed by ? behaves as if it were followed by ?: but named parentheses
2483     can still be used for capturing (and they will acquire numbers in the usual
2484     way).
2485    
2486     41. Redesigned the return codes from the match() function into yes/no/error so
2487     that errors can be passed back from deep inside the nested calls. A malloc
2488     failure while inside a recursive subpattern call now causes the
2489     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2490    
2491     42. It is now possible to set a limit on the number of times the match()
2492     function is called in a call to pcre_exec(). This facility makes it possible to
2493     limit the amount of recursion and backtracking, though not in a directly
2494     obvious way, because the match() function is used in a number of different
2495     circumstances. The count starts from zero for each position in the subject
2496     string (for non-anchored patterns). The default limit is, for compatibility, a
2497     large number, namely 10 000 000. You can change this in two ways:
2498    
2499     (a) When configuring PCRE before making, you can use --with-match-limit=n
2500     to set a default value for the compiled library.
2501    
2502     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2503     a different value is set. See 45 below.
2504    
2505     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2506    
2507     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2508     of things that can be changed at compile time. The first argument specifies
2509     what is wanted and the second points to where the information is to be placed.
2510     The current list of available information is:
2511    
2512     PCRE_CONFIG_UTF8
2513    
2514     The output is an integer that is set to one if UTF-8 support is available;
2515     otherwise it is set to zero.
2516    
2517     PCRE_CONFIG_NEWLINE
2518    
2519     The output is an integer that it set to the value of the code that is used for
2520     newline. It is either LF (10) or CR (13).
2521    
2522     PCRE_CONFIG_LINK_SIZE
2523    
2524     The output is an integer that contains the number of bytes used for internal
2525     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2526    
2527     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2528    
2529     The output is an integer that contains the threshold above which the POSIX
2530     interface uses malloc() for output vectors. See item 31 above.
2531    
2532     PCRE_CONFIG_MATCH_LIMIT
2533    
2534     The output is an unsigned integer that contains the default limit of the number
2535     of match() calls in a pcre_exec() execution. See 42 above.
2536    
2537     44. pcretest has been upgraded by the addition of the -C option. This causes it
2538     to extract all the available output from the new pcre_config() function, and to
2539     output it. The program then exits immediately.
2540    
2541     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2542     order to support additional features. One way would have been to define
2543     pcre_exec2() (for example) with extra arguments, but this would not have been
2544     extensible, and would also have required all calls to the original function to
2545     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2546     is used for passing in "extra" data from pcre_study().
2547    
2548     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2549     contains the following fields:
2550    
2551     flags a bitmap indicating which of the following fields are set
2552     study_data opaque data from pcre_study()
2553     match_limit a way of specifying a limit on match() calls for a specific
2554     call to pcre_exec()
2555     callout_data data for callouts (see 49 below)
2556    
2557     The flag bits are also defined in pcre.h, and are
2558    
2559     PCRE_EXTRA_STUDY_DATA
2560     PCRE_EXTRA_MATCH_LIMIT
2561     PCRE_EXTRA_CALLOUT_DATA
2562    
2563     The pcre_study() function now returns one of these new pcre_extra blocks, with
2564     the actual study data pointed to by the study_data field, and the
2565     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2566     before. That is, this change is entirely upwards-compatible and requires no
2567     change to existing code.
2568    
2569     If you want to pass in additional data to pcre_exec(), you can either place it
2570     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2571     block.
2572    
2573     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2574     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2575     times with different match limits, until it finds the minimum value needed for
2576     pcre_exec() to complete. The value is then output. This can be instructive; for
2577     most simple matches the number is quite small, but for pathological cases it
2578     gets very large very quickly.
2579    
2580     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2581     returns the size of the data block pointed to by the study_data field in a
2582     pcre_extra block, that is, the value that was passed as the argument to
2583     pcre_malloc() when PCRE was getting memory in which to place the information
2584     created by pcre_study(). The fourth argument should point to a size_t variable.
2585     pcretest has been extended so that this information is shown after a successful
2586     pcre_study() call when information about the compiled regex is being displayed.
2587    
2588     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2589     because what follows is always an absolute path. (Later: it turns out that this
2590     is more than cosmetic for MinGW, because it doesn't like empty path
2591     components.)
2592    
2593     49. Some changes have been made to the callout feature (see 28 above):
2594    
2595     (i) A callout function now has three choices for what it returns:
2596    
2597     0 => success, carry on matching
2598     > 0 => failure at this point, but backtrack if possible
2599     < 0 => serious error, return this value from pcre_exec()
2600    
2601     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2602     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2603     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2604     use by callout functions. It will never be used by PCRE itself.
2605    
2606     (ii) The pcre_extra structure (see 45 above) has a void * field called
2607     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2608     pcre_callout_block structure has a field of the same name. The contents of
2609     the field passed in the pcre_extra structure are passed to the callout
2610     function in the corresponding field in the callout block. This makes it
2611     easier to use the same callout-containing regex from multiple threads. For
2612     testing, the pcretest program has a new data escape
2613    
2614     \C*n pass the number n (may be negative) as callout_data
2615    
2616     If the callout function in pcretest receives a non-zero value as
2617     callout_data, it returns that value.
2618    
2619     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2620     there were some redundant $(CFLAGS) in commands that are now specified as
2621     $(LINK), which already includes $(CFLAGS).
2622    
2623     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2624     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2625     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2626     one-byte characters throughout. Note that case-insensitive matching applies
2627     only to characters whose values are less than 256. PCRE doesn't support the
2628     notion of cases for higher-valued characters.
2629    
2630     (i) A character class whose characters are all within 0-255 is handled as
2631     a bit map, and the map is inverted for negative classes. Previously, a
2632     character > 255 always failed to match such a class; however it should
2633     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2634    
2635     (ii) A negated character class with a single character < 255 is coded as
2636     "not this character" (OP_NOT). This wasn't working properly when the test
2637     character was multibyte, either singly or repeated.
2638    
2639     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2640     mode, for example: \x{100}{2,3}.
2641    
2642     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2643     singly or repeated) now correctly test multibyte characters. However,
2644     PCRE doesn't recognize any characters with values greater than 255 as
2645     digits, spaces, or word characters. Such characters always match \D, \S,
2646     and \W, and never match \d, \s, or \w.
2647    
2648     (v) Classes may now contain characters and character ranges with values
2649     greater than 255. For example: [ab\x{100}-\x{400}].
2650    
2651     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2652     PCRE in UTF-8 mode.
2653    
2654     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2655     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2656     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2657     value.)
2658    
2659     53. The single man page has become too large. I have therefore split it up into
2660     a number of separate man pages. These also give rise to individual HTML pages;
2661     these are now put in a separate directory, and there is an index.html page that
2662     lists them all. Some hyperlinking between the pages has been installed.
2663    
2664     54. Added convenience functions for handling named capturing parentheses.
2665    
2666     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2667     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2668     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2669     are faulted.
2670    
2671     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2672     calling configure. These values are used when compiling the dftables.c program
2673     which is run to generate the source of the default character tables. They
2674     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2675     you will need to set these values.
2676    
2677     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2678    
2679    
2680     Version 3.9 02-Jan-02
2681 nigel 61 ---------------------
2682    
2683     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2684    
2685     2. If --disable-static was given, the building process failed when trying to
2686     build pcretest and pcregrep. (For some reason it was using libtool to compile
2687     them, which is not right, as they aren't part of the library.)
2688    
2689    
2690 nigel 59 Version 3.8 18-Dec-01
2691     ---------------------
2692    
2693     1. The experimental UTF-8 code was completely screwed up. It was packing the
2694     bytes in the wrong order. How dumb can you get?
2695    
2696    
2697 nigel 57 Version 3.7 29-Oct-01
2698     ---------------------
2699    
2700     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2701     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2702     this didn't happen under Solaris 8, where I normally test things.
2703    
2704 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2705     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2706     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2707     this fix an hour or so after the initial 3.7 release.)
2708 nigel 57
2709 nigel 59
2710 nigel 55 Version 3.6 23-Oct-01
2711     ---------------------
2712    
2713     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2714     offsets passed as NULL with zero offset count.
2715    
2716     2. The config.guess and config.sub files had not been updated when I moved to
2717     the latest autoconf.
2718    
2719    
2720 nigel 53 Version 3.5 15-Aug-01
2721     ---------------------
2722 nigel 5
2723 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2724     had been forgotten.
2725    
2726     2. By using declared but undefined structures, we can avoid using "void"
2727     definitions in pcre.h while keeping the internal definitions of the structures
2728     private.
2729    
2730     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2731     user point of view, this means that both static and shared libraries are built
2732     by default, but this can be individually controlled. More of the work of
2733     handling this static/shared cases is now inside libtool instead of PCRE's make
2734     file.
2735    
2736     4. The pcretest utility is now installed along with pcregrep because it is
2737     useful for users (to test regexs) and by doing this, it automatically gets
2738     relinked by libtool. The documentation has been turned into a man page, so
2739     there are now .1, .txt, and .html versions in /doc.
2740    
2741     5. Upgrades to pcregrep:
2742     (i) Added long-form option names like gnu grep.
2743     (ii) Added --help to list all options with an explanatory phrase.
2744     (iii) Added -r, --recursive to recurse into sub-directories.
2745     (iv) Added -f, --file to read patterns from a file.
2746    
2747     6. pcre_exec() was referring to its "code" argument before testing that
2748     argument for NULL (and giving an error if it was NULL).
2749    
2750     7. Upgraded Makefile.in to allow for compiling in a different directory from
2751     the source directory.
2752    
2753     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2754     options bits, the pointer it was passed was to an int instead of to an unsigned
2755     long int. This mattered only on 64-bit systems.
2756    
2757     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2758     generated) instead of pcre.in, which it its source. Also made the same change
2759     in several of the .c files.
2760    
2761     10. A new release of gcc defines printf() as a macro, which broke pcretest
2762     because it had an ifdef in the middle of a string argument for printf(). Fixed
2763     by using separate calls to printf().
2764    
2765     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2766     script, to force use of CR or LF instead of \n in the source. On non-Unix
2767     systems, the value can be set in config.h.
2768    
2769     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2770     absolute limit. Changed the text of the error message to make this clear, and
2771     likewise updated the man page.
2772    
2773     13. The limit of 99 on the number of capturing subpatterns has been removed.
2774     The new limit is 65535, which I hope will not be a "real" limit.
2775    
2776    
2777 nigel 51 Version 3.4 22-Aug-00
2778     ---------------------
2779    
2780     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2781    
2782     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2783    
2784    
2785 nigel 49 Version 3.3 01-Aug-00
2786     ---------------------
2787    
2788     1. If an octal character was given, but the value was greater than \377, it
2789     was not getting masked to the least significant bits, as documented. This could
2790     lead to crashes in some systems.
2791    
2792     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2793     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2794    
2795     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2796     These just pass their arguments on to (pcre_free)(), but they are provided
2797     because some uses of PCRE bind it to non-C systems that can call its functions,
2798     but cannot call free() or pcre_free() directly.
2799    
2800     4. Add "make test" as a synonym for "make check". Corrected some comments in
2801     the Makefile.
2802    
2803     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2804     Makefile.
2805    
2806     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2807     command called pgrep for grepping around the active processes.
2808    
2809     7. Added the beginnings of support for UTF-8 character strings.
2810    
2811     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2812     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2813     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2814     out for the ar command.)
2815    
2816    
2817 nigel 47 Version 3.2 12-May-00
2818     ---------------------
2819    
2820     This is purely a bug fixing release.
2821    
2822     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2823     of ZA. This was just one example of several cases that could provoke this bug,
2824     which was introduced by change 9 of version 2.00. The code for breaking
2825     infinite loops after an iteration that matches an empty string was't working
2826     correctly.
2827    
2828     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2829     when matched against abbab (for example). After matching an empty string, it
2830     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2831     caused it to match further down the string than it should.
2832    
2833     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2834     was there because it doesn't seem to be needed, and it causes trouble on some
2835     systems, as it is not a Standard C header. It has been removed.
2836    
2837     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2838     were reported on the Macintosh. The changes were from
2839    
2840     while ((c = *(++ptr)) != 0 && c != '\n');
2841     to
2842     while ((c = *(++ptr)) != 0 && c != '\n') ;
2843    
2844     Totally extraordinary, but if that's what it takes...
2845    
2846     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2847     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2848     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2849     assumes the way PCRE uses memmove() (always moving upwards).
2850    
2851     6. PCRE is being used in one environment where strchr() is not available. There
2852     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2853     faster code anyway.
2854    
2855    
2856 nigel 45 Version 3.1 09-Feb-00
2857     ---------------------
2858    
2859     The only change in this release is the fixing of some bugs in Makefile.in for
2860     the "install" target:
2861    
2862     (1) It was failing to install pcreposix.h.
2863    
2864     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2865    
2866    
2867 nigel 43 Version 3.0 01-Feb-00
2868     ---------------------
2869 nigel 41
2870     1. Add support for the /+ modifier to perltest (to output $` like it does in
2871     pcretest).
2872    
2873     2. Add support for the /g modifier to perltest.
2874    
2875     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2876     matches null strings.
2877    
2878     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2879     pattern. Perl treats empty patterns specially - it reuses the most recent
2880     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2881     effect.
2882    
2883     5. The POSIX interface was broken in that it was just handing over the POSIX
2884     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2885     required a bigger vector, with some working space on the end. This means that
2886     the POSIX wrapper now has to get and free some memory, and copy the results.
2887    
2888 nigel 43 6. Added some simple autoconf support, placing the test data and the
2889     documentation in separate directories, re-organizing some of the
2890     information files, and making it build pcre-config (a GNU standard). Also added
2891     libtool support for building PCRE as a shared library, which is now the
2892     default.
2893 nigel 41
2894 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2895     09 are not valid octal constants. Single digits will be used for minor values
2896     less than 10.
2897    
2898     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2899     existing programs that set these in the POSIX interface can use PCRE without
2900     modification.
2901    
2902     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2903     return all that pcre_info() returns, plus additional data. The pcre_info()
2904     function is retained for compatibility, but is considered to be obsolete.
2905    
2906     10. Added experimental recursion feature (?R) to handle one common case that
2907     Perl 5.6 will be able to do with (?p{...}).
2908    
2909     11. Added support for POSIX character classes like [:alpha:], which Perl is
2910     adopting.
2911    
2912    
2913 nigel 39 Version 2.08 31-Aug-99
2914     ----------------------
2915    
2916     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2917     trying to match at the startoffset position, but instead was moving forward to
2918     the next newline as if a previous match had failed.
2919    
2920     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2921     and could get into a loop if a null string was matched other than at the start
2922     of the subject.
2923    
2924     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2925     be distinguished at compile time, and for completeness also added PCRE_DATE.
2926    
2927     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2928     in GnuWin32 environments.
2929    
2930    
2931 nigel 37 Version 2.07 29-Jul-99
2932     ----------------------
2933    
2934     1. The documentation is now supplied in plain text form and HTML as well as in
2935     the form of man page sources.
2936    
2937     2. C++ compilers don't like assigning (void *) values to other pointer types.
2938     In particular this affects malloc(). Although there is no problem in Standard
2939     C, I've put in casts to keep C++ compilers happy.
2940    
2941     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2942     should be (const char *).
2943    
2944     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2945     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2946     However, I haven't made this a standard facility. The documentation doesn't
2947     mention it, and the Makefile doesn't support it.
2948    
2949     5. The Makefile now contains an "install" target, with editable destinations at
2950     the top of the file. The pcretest program is not installed.
2951    
2952     6. pgrep -V now gives the PCRE version number and date.
2953    
2954     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2955     causing the entire string to be ignored, instead of just the last character.
2956    
2957     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2958     non-matching string, it can take a very, very long time, even for strings of
2959     quite modest length, because of the nested recursion. PCRE now does better in
2960     some of these cases. It does this by remembering the last required literal
2961     character in the pattern, and pre-searching the subject to ensure it is present
2962     before running the real match. In other words, it applies a heuristic to detect
2963     some types of certain failure quickly, and in the above example, if presented
2964     with a string that has no trailing " it gives "no match" very quickly.
2965    
2966     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2967     other alternatives are tried instead.
2968    
2969    
2970 nigel 35 Version 2.06 09-Jun-99
2971     ----------------------
2972    
2973     1. Change pcretest's output for amount of store used to show just the code
2974     space, because the remainder (the data block) varies in size between 32-bit and
2975     64-bit systems.
2976    
2977     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2978     start matching at. This allows lookbehinds to work when searching for multiple
2979     occurrences in a string.
2980    
2981     3. Added additional options to pcretest for testing multiple occurrences:
2982    
2983     /+ outputs the rest of the string that follows a match
2984     /g loops for multiple occurrences, using the new startoffset argument
2985     /G loops for multiple occurrences by passing an incremented pointer
2986    
2987     4. PCRE wasn't doing the "first character" optimization for patterns starting
2988     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2989     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2990     the letter 'x'. On long subject strings, this gives a significant speed-up.
2991    
2992    
2993 nigel 33 Version 2.05 21-Apr-99
2994     ----------------------
2995    
2996     1. Changed the type of magic_number from int to long int so that it works
2997     properly on 16-bit systems.
2998    
2999     2. Fixed a bug which caused patterns starting with .* not to work correctly
3000     when the subject string contained newline characters. PCRE was assuming
3001     anchoring for such patterns in all cases, which is not correct because .* will
3002     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3003     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3004     must be retried after every newline in the subject.
3005    
3006    
3007 nigel 31 Version 2.04 18-Feb-99
3008     ----------------------
3009    
3010     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3011     computation of the store needed to hold the pattern was incorrect (too large).
3012     If such patterns were nested a few deep, this could multiply and become a real
3013     problem.
3014    
3015     2. Added /M option to pcretest to show the memory requirement of a specific
3016     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3017    
3018     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3019     compiled in such a way that the backtracking after subsequent failure was
3020     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3021     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3022    
3023    
3024 nigel 29 Version 2.03 02-Feb-99
3025     ----------------------
3026    
3027     1. Fixed typo and small mistake in man page.
3028    
3029 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3030     LICENCE file containing the conditions.
3031 nigel 29
3032     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3033     Perl, that is the internal \ allows the delimiter to be included in the
3034     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3035     the final delimiter, add \ to the end of the pattern (to test the error).
3036    
3037     4. Added the convenience functions for extracting substrings after a successful
3038     match. Updated pcretest to make it able to test these functions.
3039    
3040    
3041 nigel 27 Version 2.02 14-Jan-99
3042     ----------------------
3043    
3044     1. Initialized the working variables associated with each extraction so that
3045     their saving and restoring doesn't refer to uninitialized store.
3046    
3047     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3048     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3049     fix the problem.
3050    
3051     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3052     calls, and wasn't printing the correct value for compiling calls. Increased the
3053     default value of LOOPREPEAT, and the number of significant figures in the
3054     times.
3055    
3056     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3057    
3058     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3059     a building problem on Windows NT with a FAT file system.
3060    
3061    
3062 nigel 25 Version 2.01 21-Oct-98
3063     ----------------------
3064    
3065     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3066     to character tables built by pcre_maketables() in the current locale. If NULL
3067     is passed, the default tables are used.
3068    
3069    
3070 nigel 23 Version 2.00 24-Sep-98
3071 nigel 21 ----------------------
3072    
3073 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3074     it any more.
3075    
3076     2. Allow quantification of (?>) groups, and make it work correctly.
3077    
3078     3. The first character computation wasn't working for (?>) groups.
3079    
3080     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3081     end of the subject) and add 5.005's \z, which really does match only at the
3082     very end of the subject.
3083    
3084     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3085    
3086     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3087     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3088     localized options. All options to pcre_study() were also removed.
3089    
3090     7. Add other new features from 5.005:
3091    
3092     $(?<= positive lookbehind
3093     $(?<! negative lookbehind
3094     (?imsx-imsx) added the unsetting capability
3095     such a setting is global if at outer level; local otherwise
3096     (?imsx-imsx:) non-capturing groups with option setting
3097     (?(cond)re|re) conditional pattern matching
3098    
3099     A backreference to itself in a repeated group matches the previous
3100     captured string.
3101    
3102     8. General tidying up of studying (both automatic and via "study")
3103     consequential on the addition of new assertions.
3104    
3105     9. As in 5.005, unlimited repeated groups that could match an empty substring
3106     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3107     runtime if any iteration does actually match an empty substring.
3108    
3109     10. Include the RunTest script in the distribution.
3110    
3111     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3112     discrepancies, some of which were old and were also with respect to 5.004. They
3113     have now been fixed.
3114    
3115    
3116     Version 1.09 28-Apr-98
3117     ----------------------
3118    
3119 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3120     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3121     program crashes, or just wrong answers. This did not apply to negated classes
3122     containing more than one character, or to minima other than one.
3123    
3124    
3125 nigel 19 Version 1.08 27-Mar-98
3126     ----------------------
3127    
3128     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3129    
3130     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3131     latter must appear before anything that relies on it in the pattern.
3132    
3133    
3134 nigel 17 Version 1.07 16-Feb-98
3135     ----------------------
3136    
3137     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3138     repeat of a potentially empty string).
3139    
3140    
3141 nigel 15 Version 1.06 23-Jan-98
3142     ----------------------
3143    
3144     1. Added Markus Oberhumer's little patches for C++.
3145    
3146     2. Literal strings longer than 255 characters were broken.
3147    
3148    
3149 nigel 13 Version 1.05 23-Dec-97
3150     ----------------------
3151    
3152     1. Negated character classes containing more than one character were failing if
3153     PCRE_CASELESS was set at run time.
3154    
3155    
3156 nigel 11 Version 1.04 19-Dec-97
3157     ----------------------
3158    
3159     1. Corrected the man page, where some "const" qualifiers had been omitted.
3160    
3161     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3162     input syntax.
3163    
3164     3. Fixed memory leak which occurred when a regex with back references was
3165     matched with an offsets vector that wasn't big enough. The temporary memory
3166     that is used in this case wasn't being freed if the match failed.
3167    
3168     4. Tidied pcretest to ensure it frees memory that it gets.
3169    
3170     5. Temporary memory was being obtained in the case where the passed offsets
3171     vector was exactly big enough.
3172    
3173     6. Corrected definition of offsetof() from change 5 below.
3174    
3175     7. I had screwed up change 6 below and broken the rules for the use of
3176     setjmp(). Now fixed.
3177    
3178    
3179 nigel 9 Version 1.03 18-Dec-97
3180     ----------------------
3181    
3182     1. A erroneous regex with a missing opening parenthesis was correctly
3183     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3184     on some systems.
3185    
3186     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3187     it was reported that one broken compiler failed on the former because "code" is
3188     also an independent variable.
3189    
3190     3. The erroneous regex a[]b caused an array overrun reference.
3191    
3192     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3193     fail on data ending with that character. (It was going on too far, and checking
3194     the next character, typically a binary zero.) This was specific to the
3195     optimized code for single-character negative classes.
3196    
3197     5. Added a contributed patch from the TIN world which does the following:
3198    
3199     + Add an undef for memmove, in case the the system defines a macro for it.
3200    
3201     + Add a definition of offsetof(), in case there isn't one. (I don't know
3202     the reason behind this - offsetof() is part of the ANSI standard - but
3203     it does no harm).
3204    
3205     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3206     most of the places where whitespace preceded '#'. I have given up and
3207     allowed the remaining 2 cases to be at the margin.
3208    
3209     + Rename some variables in pcre to eliminate shadowing. This seems very
3210     pedantic, but does no harm, of course.
3211    
3212     6. Moved the call to setjmp() into its own function, to get rid of warnings
3213     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3214    
3215     7. Constructs such as \d{8,} were compiling into the equivalent of
3216 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3217 nigel 9 outcome, but in this particular case used more store than had been allocated,
3218     which caused the bug to be discovered because it threw up an internal error.
3219    
3220     8. The debugging code in both pcre and pcretest for outputting the compiled
3221     form of a regex was going wrong in the case of back references followed by
3222     curly-bracketed repeats.
3223    
3224    
3225 nigel 7 Version 1.02 12-Dec-97
3226     ----------------------
3227    
3228     1. Typos in pcre.3 and comments in the source fixed.
3229    
3230     2. Applied a contributed patch to get rid of places where it used to remove
3231     'const' from variables, and fixed some signed/unsigned and uninitialized
3232     variable warnings.
3233    
3234     3. Added the "runtest" target to Makefile.
3235    
3236     4. Set default compiler flag to -O2 rather than just -O.
3237    
3238    
3239 nigel 5 Version 1.01 19-Nov-97
3240     ----------------------
3241    
3242     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3243     like /([ab]*)*/, that is, for classes with more than one character in them.
3244    
3245     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3246     as /((?>a*))*/ (a PCRE_EXTRA facility).
3247    
3248    
3249     Version 1.00 18-Nov-97
3250     ----------------------
3251    
3252     1. Added compile-time macros to support systems such as SunOS4 which don't have
3253     memmove() or strerror() but have other things that can be used instead.
3254    
3255     2. Arranged that "make clean" removes the executables.
3256    
3257    
3258 nigel 3 Version 0.99 27-Oct-97
3259     ----------------------
3260    
3261     1. Fixed bug in code for optimizing classes with only one character. It was
3262     initializing a 32-byte map regardless, which could cause it to run off the end
3263     of the memory it had got.
3264    
3265     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3266    
3267    
3268     Version 0.98 22-Oct-97
3269     ----------------------
3270    
3271     1. Fixed bug in code for handling temporary memory usage when there are more
3272     back references than supplied space in the ovector. This could cause segfaults.
3273    
3274    
3275     Version 0.97 21-Oct-97
3276     ----------------------
3277    
3278     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3279    
3280     2. Optimized negated single characters not to use a bit map.
3281    
3282     3. Brought error texts together as macro definitions; clarified some of them;
3283     fixed one that was wrong - it said "range out of order" when it meant "invalid
3284     escape sequence".
3285    
3286     4. Changed some char * arguments to const char *.
3287    
3288     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3289    
3290     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3291     pcretest.
3292    
3293    
3294     Version 0.96 16-Oct-97
3295     ----------------------
3296    
3297     1. Added a simple "pgrep" utility to the distribution.
3298    
3299     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3300     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3301     where "ddd" means "one or more decimal digits".
3302    
3303     3. Fixed serious bug. If a pattern had a back reference, but the call to
3304     pcre_exec() didn't supply a large enough ovector to record the related
3305     identifying subpattern, the match always failed. PCRE now remembers the number
3306     of the largest back reference, and gets some temporary memory in which to save
3307     the offsets during matching if necessary, in order to ensure that
3308     backreferences always work.
3309    
3310     4. Increased the compatibility with Perl in a number of ways:
3311    
3312     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3313     to request this handling. The option can be set at compile or exec time.
3314    
3315     (b) $ matches before a terminating newline by default; an option
3316     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3317     mode). The option can be set at compile or exec time.
3318    
3319     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3320     the same as Perl's. If the decimal number it represents is less than 10
3321     or there aren't that many previous left capturing parentheses, an octal
3322     escape is read. Inside a character class, it's always an octal escape,
3323     even if it is a single digit.
3324    
3325     (d) An escaped but undefined alphabetic character is taken as a literal,
3326     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3327     escapes.
3328    
3329     (e) {0} is now permitted. (The previous item is removed from the compiled
3330     pattern).
3331    
3332     5. Changed all the names of code files so that the basic parts are no longer
3333     than 10 characters, and abolished the teeny "globals.c" file.
3334    
3335     6. Changed the handling of character classes; they are now done with a 32-byte
3336     bit map always.
3337    
3338     7. Added the -d and /D options to pcretest to make it possible to look at the
3339     internals of compilation without having to recompile pcre.
3340    
3341    
3342     Version 0.95 23-Sep-97
3343     ----------------------
3344    
3345     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3346     \x20 at the start of a run of normal characters. These were being treated as
3347     real characters, instead of the source characters being re-checked.
3348    
3349    
3350     Version 0.94 18-Sep-97
3351     ----------------------
3352    
3353     1. The functions are now thread-safe, with the caveat that the global variables
3354     containing pointers to malloc() and free() or alternative functions are the
3355     same for all threads.
3356    
3357     2. Get pcre_study() to generate a bitmap of initial characters for non-
3358     anchored patterns when this is possible, and use it if passed to pcre_exec().
3359    
3360    
3361     Version 0.93 15-Sep-97
3362     ----------------------
3363    
3364     1. /(b)|(:+)/ was computing an incorrect first character.
3365    
3366     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3367     but not actually doing anything yet.
3368    
3369     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3370     as Perl does (e.g. [-az] or [az-]).
3371    
3372     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3373     all possible positions.
3374    
3375     5. Split up into different modules to avoid including unneeded functions in a
3376     compiled binary. However, compile and exec are still in one module. The "study"
3377     function is split off.
3378    
3379     6. The character tables are now in a separate module whose source is generated
3380     by an auxiliary program - but can then be edited by hand if required. There are
3381     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3382     toupper() in the code.
3383    
3384     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3385     make them global. Abolish the function for setting them, as the caller can now
3386     set them directly.
3387    
3388    
3389     Version 0.92 11-Sep-97
3390     ----------------------
3391    
3392     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3393     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3394    
3395     2. Caseless matching was not working in character classes if the characters in
3396     the pattern were in upper case.
3397    
3398     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3399    
3400     4. Make PCRE_ANCHORED public and accept as a compile option.
3401    
3402     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3403     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3404     pass them.
3405    
3406     6. Give an error if bad option bits passed at compile or run time.
3407    
3408     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3409     pcretest to cause it to pass that flag.
3410    
3411     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3412     options, and the first character, if set.
3413    
3414     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3415    
3416    
3417     Version 0.91 10-Sep-97
3418     ----------------------
3419    
3420     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3421     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3422    
3423     2. PCRE was looping on encountering an indefinitely repeated back reference to
3424     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3425     Perl does - treats the match as successful.
3426    
3427     ****

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