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Mon Jul 14 15:45:32 2008 UTC (6 years, 9 months ago) by ph10
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Lazy qualifiers were not always working in UTF-8 mode (8.0/15).

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 349 Version 8.0 02 Jul-08
5     ---------------------
7     1. Replaced UCP searching code with optimized version as implemented for Ad
8     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
10     to 5 times on some simple patterns that I tested. Permission was given to
11     distribute the MultiStage2.py script that generates the tables (it's not in
12     the tarball, but is in the Subversion repository).
13 ph10 349
14 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15     scripts.
16 ph10 358
17 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18     a group with a zero qualifier. The result of the study could be incorrect,
19 ph10 358 or the function might crash, depending on the pattern.
21     4. Caseless matching was not working for non-ASCII characters in back
22 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23 ph10 358 It now works when Unicode Property Support is available.
25 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
26     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28 ph10 358 truncation.
29 ph10 349
30 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
32 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
33     pointers, in case they are 64-bit values.
34 ph10 358
35     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
36     test 2 if it fails.
37 ph10 359
38     9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
39     and a #define of that name to empty if it is not externally set. This is to
40     allow users of MSVC to set it if necessary.
42     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
43     the convenience functions in the pcre_get.c source file.
44 ph10 360
45     11. An option change at the start of a pattern that had top-level alternatives
46     could cause overwriting and/or a crash. This command provoked a crash in
47     some environments:
49     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
51     This potential security problem was recorded as CVE-2008-2371.
52 ph10 361
53     12. For a pattern where the match had to start at the beginning or immediately
54     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
55     pcre_dfa_exec() could read past the end of the passed subject if there was
56     no match. To help with detecting such bugs (e.g. with valgrind), I modified
57     pcretest so that it places the subject at the end of its malloc-ed buffer.
58 ph10 364
59     13. The change to pcretest in 12 above threw up a couple more cases when pcre_
60     exec() might read past the end of the data buffer in UTF-8 mode.
62     14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
63     the data contained the byte 0x85 as part of a UTF-8 character within its
64 ph10 365 first line. This applied both to normal and DFA matching.
65 ph10 366
66     15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
67     /^[^d]*?$/8 failed to match "abc".
68 ph10 351
69 ph10 357
70 ph10 347 Version 7.7 07-May-08
71 ph10 321 ---------------------
73     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
74 ph10 345 a string to a long long, pretend we don't even have a long long." This is
75 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
76 ph10 345
77 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
78     pre-7.6 versions, which defined a global no_arg variable instead of putting
79 ph10 332 it in the RE class. (See also #8 below.)
80 ph10 345
81     3. Remove a line of dead code, identified by coverity and reported by Nuno
82     Lopes.
84 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
85 ph10 321
86 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
87 ph10 345 of files, instead of just to the final components.
89 ph10 324 (2) If there was more than one level of directory, the subdirectories were
90     skipped unless they satisfied the include/exclude conditions. This is
91     inconsistent with GNU grep (and could even be seen as contrary to the
92     pcregrep specification - which I improved to make it absolutely clear).
93     The action now is always to scan all levels of directory, and just
94     apply the include/exclude patterns to regular files.
95 ph10 345
96 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
97 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
99 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
100 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
101 ph10 326 doesn't support NULs in patterns.
102 ph10 345
103     7. Added some missing "const"s to declarations of static tables in
104     pcre_compile.c and pcre_dfa_exec.c.
106 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
107 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
108 ph10 345 first patch. And a third patch - this was a messy problem.)
109 ph10 321
110 ph10 345 9. Applied Craig's patch to remove the use of push_back().
112 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
113     matching function regexec().
114 ph10 345
115     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
116     which, however, unlike Perl's \g{...}, are subroutine calls, not back
117 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
118     Oniguruma does).
119 ph10 345
120     12. Previously, a group with a zero repeat such as (...){0} was completely
121 ph10 335 omitted from the compiled regex. However, this means that if the group
122     was called as a subroutine from elsewhere in the pattern, things went wrong
123 ph10 345 (an internal error was given). Such groups are now left in the compiled
124     pattern, with a new opcode that causes them to be skipped at execution
125 ph10 335 time.
126 ph10 345
127 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
128     to the way PCRE behaves:
129 ph10 345
130 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
131 ph10 345
132     (b) A back reference to an unmatched subpattern matches an empty string
133 ph10 336 (Perl fails the current match path).
134 ph10 345
135 ph10 341 (c) A data ] in a character class must be notated as \] because if the
136 ph10 345 first data character in a class is ], it defines an empty class. (In
137 ph10 341 Perl it is not possible to have an empty class.) The empty class []
138     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
139     The negative empty class [^] matches any one character, independently
140     of the DOTALL setting.
141 ph10 345
142     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
143 ph10 340 non-existent subpattern following a character class starting with ']' and
144     containing () gave an internal compiling error instead of "reference to
145     non-existent subpattern". Fortunately, when the pattern did exist, the
146 ph10 345 compiled code was correct. (When scanning forwards to check for the
147 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
148 ph10 345 the class, so got the count wrong. When actually compiling, the reference
149 ph10 340 was subsequently set up correctly.)
150 ph10 345
151 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
152 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
153     other assertions are supported. I have made pcre_dfa_exec() support
154     (*FAIL).
156 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
157 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
158     cannot be changed at match time, I realized I could make a small
159     improvement to matching performance by compiling OP_ALLANY instead of
160     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
161     on the OP_ANY path.
163     17. Compiling pcretest on Windows with readline support failed without the
164 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
165 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
167 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
168 ph10 345 ncurses library to be included for pcretest when ReadLine support is
169     requested, but also to allow for it to be overridden. This patch came from
170     Daniel Bergström.
171 ph10 347
172 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
173 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
174     any errors with the current Unicode tables. Thanks to Peter Kankowski for
175     spotting this.
176 ph10 324
177 ph10 332
178 ph10 319 Version 7.6 28-Jan-08
179 ph10 300 ---------------------
181 ph10 302 1. A character class containing a very large number of characters with
182     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
183     overflow.
184 ph10 309
185     2. Patch to cut out the "long long" test in pcrecpp_unittest when
186     HAVE_LONG_LONG is not defined.
188 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
189 ph10 304 bring them up to date and include new features. This patch includes:
190 ph10 309
191 ph10 304 - Fixed PH's badly added libz and libbz2 support.
192     - Fixed a problem with static linking.
193 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
194 ph10 304 - Fixed dftables problem and added an option.
195     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
197     - Added readline support for pcretest.
198 ph10 309 - Added an listing of the option settings after cmake has run.
200 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
201     "pcre.dll" under mingw when using Configure/Make. I added stuff to
202     Makefile.am that cause it to include this special target, without
203     affecting anything else. Note that the same mingw target plus all
204     the other distribution libraries and programs are now supported
205     when configuring with CMake (see 6 below) instead of with
206     Configure/Make.
207 ph10 309
208 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
209     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
210 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
211     solves the problem, but it does no harm.
212 ph10 313
213 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
214 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
215 ph10 314 with CMake, and also correct the comment about stack recursion.
216 ph10 313
217 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
218 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
219     of a program that users should build themselves after PCRE is installed, so
220     building it automatically is not really right. What is more, it gave
221 ph10 312 trouble in some build environments.
222 ph10 300
223 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
224 ph10 308
225 ph10 319
226 ph10 298 Version 7.5 10-Jan-08
227 ph10 263 ---------------------
229     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
230     values in parens when parsing an RE using the C++ wrapper."
231 ph10 286
232 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
233     Characters greater than 255 were excluded from the class instead of being
234     included.
235 ph10 286
236     3. The same bug as (2) above applied to negated POSIX classes such as
237 ph10 265 [:^space:].
238 ph10 286
239 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
240     defined or documented. It seems to have been a typo for PCRE_STATIC, so
241 ph10 286 I have changed it.
243 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
244 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
245     first named subpattern whose name started with "a" (in other words, the
246 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
247     expected" is now given for (?&) (a zero-length name), and this patch also
248     makes it give the same error for \k'' (previously it complained that that
249     was a reference to a non-existent subpattern).
250 ph10 286
251 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
252 ph10 286 this is right because (?- can be followed by option settings as well as by
253 ph10 269 digits. I have, however, made the messages clearer.
254 ph10 286
255 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
256     than the number used in the conditional) now cause a compile-time error.
257     This is actually not compatible with Perl, which accepts such patterns, but
258     treats the conditional as always being FALSE (as PCRE used to), but it
259     seems to me that giving a diagnostic is better.
260 ph10 286
261 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
262 ph10 275 and messages.
263 ph10 286
264     9. Fix two occurrences of "backslash" in comments that should have been
265     "backspace".
267     10. Remove two redundant lines of code that can never be obeyed (their function
268     was moved elsewhere).
270     11. The program that makes PCRE's Unicode character property table had a bug
271     which caused it to generate incorrect table entries for sequences of
272 ph10 277 characters that have the same character type, but are in different scripts.
273 ph10 286 It amalgamated them into a single range, with the script of the first of
274 ph10 277 them. In other words, some characters were in the wrong script. There were
275     thirteen such cases, affecting characters in the following ranges:
276 ph10 286
277 ph10 277 U+002b0 - U+002c1
278     U+0060c - U+0060d
279 ph10 286 U+0061e - U+00612
280 ph10 277 U+0064b - U+0065e
281     U+0074d - U+0076d
282     U+01800 - U+01805
283     U+01d00 - U+01d77
284     U+01d9b - U+01dbf
285     U+0200b - U+0200f
286     U+030fc - U+030fe
287     U+03260 - U+0327f
288     U+0fb46 - U+0fbb1
289     U+10450 - U+1049d
290 ph10 286
291 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
292     compatible with GNU grep in that, if there was more than one match in a
293     line, it showed only the first of them. It now behaves in the same way as
294     GNU grep.
295 ph10 286
296     13. If the -o and -v options were combined for pcregrep, it printed a blank
297     line for every non-matching line. GNU grep prints nothing, and pcregrep now
298     does the same. The return code can be used to tell if there were any
299     non-matching lines.
301 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
303     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
304 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
305 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
306     and both kinds of lookbehind were skipped).
308 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
309 ph10 284 inclusion of <windows.h> to before rather than after the definition of
310     INVALID_FILE_ATTRIBUTES (patch from David Byron).
311 ph10 263
312 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
313 ph10 286 character property caused pcre_compile() to compile bad code, which led at
314     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
315     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
316     caused the error; without that there was no problem.
317 ph10 263
318 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
319 ph10 286
320 ph10 289 19. Added --enable-pcretest-libreadline.
321 ph10 286
322 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
323 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
324 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
325     later patch that removed the other one (the right fix) and added unit tests
326     that check the return values (which was not done before).
327 ph10 292
328 ph10 291 21. Several CMake things:
329 ph10 287
330 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
331 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
332 ph10 288
333 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
334     linked with the newly-built libraries, not previously installed ones.
335 ph10 291
337 ph10 298
338     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
339     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
340     UTF-8 newline character). The key issue is that the pattern starts .*;
341     this means that the match must be either at the beginning, or after a
342     newline. The bug was in the code for advancing after a failed match and
343     checking that the new position followed a newline. It was not taking
344 ph10 294 account of UTF-8 characters correctly.
345 ph10 298
346     23. PCRE was behaving differently from Perl in the way it recognized POSIX
347     character classes. PCRE was not treating the sequence [:...:] as a
348     character class unless the ... were all letters. Perl, however, seems to
349     allow any characters between [: and :], though of course it rejects as
350     unknown any "names" that contain non-letters, because all the known class
351     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
352     for example, whereas PCRE did not - it did not recognize a POSIX character
353     class. This seemed a bit dangerous, so the code has been changed to be
354     closer to Perl. The behaviour is not identical to Perl, because PCRE will
355     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
356     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
357     Perl does, and where it didn't before.
359 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
360     Windows environments %n is disabled by default.
361 ph10 292
363 ph10 260 Version 7.4 21-Sep-07
364 ph10 230 ---------------------
366     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
367 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
368     LF". That isn't really right - the whole point of the change was to try to
369     help when there was an actual mention of one of the two characters. So now
370     the change happens only if \r or \n (or a literal CR or LF) character is
371 ph10 230 encountered.
372 ph10 231
373     2. The 32-bit options word was also used for 6 internal flags, but the numbers
374     of both had grown to the point where there were only 3 bits left.
375     Fortunately, there was spare space in the data structure, and so I have
376     moved the internal flags into a new 16-bit field to free up more option
377 ph10 230 bits.
378 ph10 231
379     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
380     but did not set the internal JCHANGED flag - either of these is enough to
381     control the way the "get" function works - but the PCRE_INFO_JCHANGED
382     facility is supposed to tell if (?J) was ever used, so now (?J) at the
383 ph10 230 start sets both bits.
385 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
386     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
387 ph10 230
388 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
390     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
391 ph10 233 compatibility, even though it is no longer used.
392 ph10 243
393     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
394 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
395 ph10 259 windows.h file is present (where different names are used). [This was
396 ph10 257 reversed later after testing - see 16 below.]
397 ph10 243
398     8. Changed all #include <config.h> to #include "config.h". There were also
399 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
400 ph10 243
401 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
402 ph10 243 sequence off the lines that it output.
404     10. It was pointed out to me that arrays of string pointers cause lots of
405     relocations when a shared library is dynamically loaded. A technique of
406     using a single long string with a table of offsets can drastically reduce
407     these. I have refactored PCRE in four places to do this. The result is
408 ph10 240 dramatic:
409 ph10 243
410 ph10 240 Originally: 290
411     After changing UCP table: 187
412 ph10 243 After changing error message table: 43
413 ph10 240 After changing table of "verbs" 36
414     After changing table of Posix names 22
415 ph10 243
416 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
417 ph10 247
418 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
419 ph10 247 unicode-properties was also set.
421 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
422 ph10 231
423 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
424     checked only for CRLF.
425 ph10 233
426 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
428 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
429 ph10 253
430 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
431 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
432     entirely. This removes changes made in 7 above.
433 ph10 256
434 ph10 261 17. The CMake files have been updated, and there is now more information about
435     building with CMake in the NON-UNIX-USE document.
436 ph10 257
437 ph10 261
438 ph10 228 Version 7.3 28-Aug-07
439 ph10 157 ---------------------
441 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
442     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
443     brackets there is not right, since it causes compilers to look for an
444     installed pcre.h, not the version that is in the source that is being
445     compiled (which of course may be different). I have changed it back to:
446 ph10 197
447 ph10 189 #include "pcre.h"
448 ph10 197
449     I have a vague recollection that the change was concerned with compiling in
450     different directories, but in the new build system, that is taken care of
451     by the VPATH setting the Makefile.
453 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
454     when the subject happened to end in the byte 0x85 (e.g. if the last
455     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
456     characters but of course it shouldn't be taken as a newline when it is part
457     of another character. The bug was that, for an unlimited repeat of . in
458     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
459     characters when looking for a newline.
460 ph10 197
461     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
463     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
464     in debug output.
466 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
467     long printing in the pcrecpp unittest when running under MinGW.
468 ph10 189
469 ph10 197 6. ESC_K was left out of the EBCDIC table.
470 ph10 189
471 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
472     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
473     limit also applies to "virtual nesting" when a pattern is recursive, and in
474     this case 1000 isn't so big. I have been able to remove this limit at the
475     expense of backing off one optimization in certain circumstances. Normally,
476     when pcre_exec() would call its internal match() function recursively and
477     immediately return the result unconditionally, it uses a "tail recursion"
478     feature to save stack. However, when a subpattern that can match an empty
479     string has an unlimited repetition quantifier, it no longer makes this
480     optimization. That gives it a stack frame in which to save the data for
481     checking that an empty string has been matched. Previously this was taken
482     from the 1000-entry workspace that had been reserved. So now there is no
483     explicit limit, but more stack is used.
484 ph10 189
485 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
486     syntax that is required for Windows, and which was going wrong for the
487     pcreposix and pcrecpp parts of the library. These were overlooked when this
488     problem was solved for the main library.
489 ph10 197
490 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
491     the size of patterns that contain repeated groups with explicit upper
492     limits. As the maximum quantifier is 65535, the maximum group length was
493     set at 30,000 so that the product of these two numbers did not overflow a
494     32-bit integer. However, it turns out that people want to use groups that
495     are longer than 30,000 bytes (though not repeat them that many times).
496     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
497     made it possible to implement the integer overflow checks in a much more
498     dynamic way, which I have now done. The artificial limitation on group
499     length has been removed - we now have only the limit on the total length of
500     the compiled pattern, which depends on the LINK_SIZE setting.
501 ph10 208
502     10. Fixed a bug in the documentation for get/copy named substring when
503     duplicate names are permitted. If none of the named substrings are set, the
504     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
505     empty string.
507     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
508     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
509     because the ] is interpreted as the first data character and the
510     terminating ] is not found. PCRE has been made compatible with Perl in this
511     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
512     cause memory overwriting.
514 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
515     string has been matched (to stop an infinite loop). It was not recognizing
516 ph10 208 a conditional subpattern that could match an empty string if that
517 ph10 206 subpattern was within another subpattern. For example, it looped when
518 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
519 ph10 206 condition was not nested. This bug has been fixed.
520 ph10 208
521 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
522     past the start of the subject in the presence of bytes with the top bit
523     set, for example "\x8aBCD".
524 ph10 211
525 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
526     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
527 ph10 200
528 ph10 211 14. Optimized (?!) to (*FAIL).
529 ph10 202
530 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
531     This restricts code points to be within the range 0 to 0x10FFFF, excluding
532     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
533     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
534     does: it's just the validity check that is more restrictive.
535 ph10 220
536     16. Inserted checks for integer overflows during escape sequence (backslash)
537     processing, and also fixed erroneous offset values for syntax errors during
538     backslash processing.
540 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
541 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
543 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
544     caused an overrun.
545 ph10 220
546     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
547     something other than just ASCII characters) inside a group that had an
548     unlimited repeat caused a loop at compile time (while checking to see
549     whether the group could match an empty string).
551 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
552     [\P{Any}] did so. (Error in the code for printing property names.)
553 ph10 210
554 ph10 220 21. An orphan \E inside a character class could cause a crash.
556     22. A repeated capturing bracket such as (A)? could cause a wild memory
557 ph10 218 reference during compilation.
558 ph10 220
559     23. There are several functions in pcre_compile() that scan along a compiled
560     expression for various reasons (e.g. to see if it's fixed length for look
561 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
562 ph10 220 present in the pattern. These operators have additional parameters compared
563     with \d, etc, and these were not being taken into account when moving along
564 ph10 218 the compiled data. Specifically:
565 ph10 220
566     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
567     length.
569     (b) An item such as \pL+ within a repeated group could cause crashes or
570 ph10 218 loops.
571 ph10 220
572 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
573 ph10 220 "reference to non-existent subpattern" error.
575 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
577 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
578 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
579 ph10 211
580 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
581 ph10 218
582 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
583 ph10 223 character were causing crashes (broken optimization).
584 ph10 227
585 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
586 ph10 227 \p or \P) caused a compile-time loop.
588 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
589     break. For example, the unstudied pattern [\r\n]A does not match the string
590     "\r\nA" because change 7.0/46 below moves the current point on by two
591     characters after failing to match at the start. However, the pattern \nA
592 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
593     the same is true. There doesn't seem any very clean way out of this, but
594     what I have chosen to do makes the common cases work: PCRE now takes note
595     of whether there can be an explicit match for \r or \n anywhere in the
596     pattern, and if so, 7.0/46 no longer applies. As part of this change,
597     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
598     pattern has explicit CR or LF references.
599 ph10 222
600 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
601 ph10 223
602 ph10 227
603 ph10 189 Version 7.2 19-Jun-07
604     ---------------------
606 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
607     which is apparently normally available under Windows.
608 ph10 159
609     2. Re-jig the pcregrep tests with different newline settings in an attempt
610     to make them independent of the local environment's newline setting.
611 ph10 157
612 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
613 ph10 165
614 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
615     was not 2, because the output contained actual offsets. The recent new
616 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
617     usable with all link sizes.
619 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
620     stack recursion. This gives a massive performance boost under BSD, but just
621 ph10 165 a small improvement under Linux. However, it saves one field in the frame
622 ph10 164 in all cases.
623 ph10 172
624 ph10 166 6. Added more features from the forthcoming Perl 5.10:
625 ph10 172
626 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
627     recursion call. It refers to the nth most recently opened parentheses.
628 ph10 172
629 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
630 ph10 172 to be opened parentheses.
632     (c) Conditions that refer to capturing parentheses can be specified
633 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
634 ph10 172
635 ph10 168 (d) \K resets the start of the current match so that everything before
636 ph10 172 is not part of it.
638 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
639 ph10 172
640 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
641 ph10 172 reference syntax.
642 ph10 182
643 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
644 ph10 182 alternative starts with the same number.
645 ph10 172
646 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
648 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
651     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
652     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
653 ph10 170 for detecting groups that can match an empty string.
654 ph10 159
655 ph10 172 9. A pattern with a very large number of alternatives (more than several
656     hundred) was running out of internal workspace during the pre-compile
657     phase, where pcre_compile() figures out how much memory will be needed. A
658     bit of new cunning has reduced the workspace needed for groups with
659     alternatives. The 1000-alternative test pattern now uses 12 bytes of
660     workspace instead of running out of the 4096 that are available.
661 ph10 182
662 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
663 ph10 172
664 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
665     The report of the bug said:
666 ph10 182
667 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
668     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
669 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
670 ph10 185
671 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
672 ph10 185 it matched the wrong number of bytes.
673 ph10 172
674 ph10 179
675 ph10 155 Version 7.1 24-Apr-07
676 ph10 98 ---------------------
678 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
679 ph10 122 that is more "standard", making use of automake and other Autotools. There
680 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
681     on this.
682 ph10 111
683     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
684     for recursive directory scanning broke on some systems because the files
685     are not scanned in any specific order and on different systems the order
686     was different. A call to "sort" has been inserted into RunGrepTest for the
687     approprate test as a short-term fix. In the longer term there may be an
688 ph10 100 alternative.
689 ph10 111
690 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
691 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
692     people do their own conversions for various reasons). The problems
693     concerned the use of low-level troff macros .br and .in. I have therefore
694     removed all such uses from the man pages (some were redundant, some could
695 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
696     HTML has been updated to handle .nf/.fi and to complain if it encounters
697     .br or .in.
698 ph10 111
699 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
700 ph10 123 arranged for config.h to be included in the distribution, with the name
701 ph10 111 config.h.generic, for the benefit of those who have to compile without
702     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
704     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
705     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
706 ph10 127 makevp.bat for the current PCRE, using the additional files
707 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
708 ph10 111
709     6. A Windows user reported a minor discrepancy with test 2, which turned out
710     to be caused by a trailing space on an input line that had got lost in his
711 ph10 102 copy. The trailing space was an accident, so I've just removed it.
712 ph10 111
713 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
714 ph10 111 that is needed.
716 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
717     as "const" (a) because they are and (b) because it helps the PHP
718     maintainers who have recently made a script to detect big data structures
719 ph10 111 in the php code that should be moved to the .rodata section. I remembered
720     to update Builducptable as well, so it won't revert if ucptable.h is ever
721 ph10 105 re-created.
722 ph10 111
723     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
724 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
725 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
726     support is not required. This saves 1.5-2K of code, which is important in
727 ph10 107 some applications.
728 ph10 111
729 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
730 ph10 111 so as not to refer to the tables, even though these functions will never be
731     called when UTF-8 support is disabled. Otherwise there are problems with a
732     shared library.
734 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
736     (a) It was defining its arguments as char * instead of void *.
738 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
739     a long time ago when I wrote it, but is no longer the case.
741 ph10 118 The emulated memove() is provided for those environments that have neither
742 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
743 ph10 118 is clearly not the case, as these two bugs were recently reported.
744 ph10 123
745 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
746 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
747     pages, and it removes trailing spaces from listed files. It also creates
748     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
749     case, it wraps all the #defines with #ifndefs. This script should be run
750 ph10 111 before "make dist".
751 ph10 123
752 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
753     with Unicode property support.
754 ph10 123
755     (a) For a maximizing quantifier, if the two different cases of the
756     character were of different lengths in their UTF-8 codings (there are
757     some cases like this - I found 11), and the matching function had to
758 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
759     were both the same length.
760 ph10 123
761     (b) When PCRE was configured to use the heap rather than the stack for
762     recursion during matching, it was not correctly preserving the data for
763     the other case of a UTF-8 character when checking ahead for a match
764     while processing a minimizing repeat. If the check also involved
765 ph10 115 matching a wide character, but failed, corruption could cause an
766     erroneous result when trying to check for a repeat of the original
767     character.
768 ph10 123
769 ph10 116 13. Some tidying changes to the testing mechanism:
770 ph10 98
771 ph10 116 (a) The RunTest script now detects the internal link size and whether there
772     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
773 ph10 123 values substituted by "configure". (The RunGrepTest script already did
774     this for UTF-8.) The configure.ac script no longer substitutes the
775     relevant variables.
777 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
778     with length and offset values. This means that the output is different
779     for different internal link sizes. Test 2 is skipped for link sizes
780     other than 2 because of this, bypassing the problem. Unfortunately,
781     there was also a test in test 3 (the locale tests) that used /B and
782 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
783     I have added a new /Z option to pcretest that replaces the length and
784     offset values with spaces. This is now used to make test 3 independent
785 ph10 122 of link size. (Test 2 will be tidied up later.)
786 ph10 123
787     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
788 ph10 122 segmentation fault instead of returning the appropriate error message.
789 ph10 134
790 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
791 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
792     This doesn't seem right; it now treats the CRLF combination as the line
793     ending, and so does not match in that case. It's only a pattern such as ^$
794     that would hit this one: something like ^ABC$ would have failed after \r
795     and then tried again after \r\n.
797 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
798 ph10 134 in an attempt to make files that differ only in their line terminators
799     compare equal. This works on Linux.
800 ph10 142
801 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
802     as it exited. This is now fixed, thanks to valgrind.
803 ph10 142
804 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
805 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
806     was because its rules for how to advance for /g after matching an empty
807 ph10 143 string at the end of a line did not allow for this case. They now check for
808     it specially.
809 ph10 150
810     20. pcretest is supposed to handle patterns and data of any length, by
811     extending its buffers when necessary. It was getting this wrong when the
812 ph10 147 buffer for a data line had to be extended.
813 ph10 150
814 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
815 ph10 150 CRLF as a newline sequence.
816 ph10 152
817 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
818 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
819     I have nevertheless tidied it up.
820 ph10 111
821 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
822 ph10 123
823 ph10 153 24. Added a man page for pcre-config.
824 ph10 152
825 ph10 153
826 nigel 93 Version 7.0 19-Dec-06
827     ---------------------
829     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
830     moving to gcc 4.1.1.
832     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
833     sys/time.h, which is documented as needed for this function. It doesn't
834     seem to matter on Linux, but it showed up on some releases of OS X.
836     3. It seems that there are systems where bytes whose values are greater than
837     127 match isprint() in the "C" locale. The "C" locale should be the
838     default when a C program starts up. In most systems, only ASCII printing
839     characters match isprint(). This difference caused the output from pcretest
840     to vary, making some of the tests fail. I have changed pcretest so that:
842     (a) When it is outputting text in the compiled version of a pattern, bytes
843     other than 32-126 are always shown as hex escapes.
845     (b) When it is outputting text that is a matched part of a subject string,
846     it does the same, unless a different locale has been set for the match
847     (using the /L modifier). In this case, it uses isprint() to decide.
849     4. Fixed a major bug that caused incorrect computation of the amount of memory
850     required for a compiled pattern when options that changed within the
851     pattern affected the logic of the preliminary scan that determines the
852     length. The relevant options are -x, and -i in UTF-8 mode. The result was
853     that the computed length was too small. The symptoms of this bug were
854     either the PCRE error "internal error: code overflow" from pcre_compile(),
855     or a glibc crash with a message such as "pcretest: free(): invalid next
856     size (fast)". Examples of patterns that provoked this bug (shown in
857     pcretest format) are:
859     /(?-x: )/x
860     /(?x)(?-x: \s*#\s*)/
861     /((?i)[\x{c0}])/8
862     /(?i:[\x{c0}])/8
864     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
865     is now done differently.
867     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
868     wrapper classes; (b) implement a new function in the C++ scanner that is
869     more efficient than the old way of doing things because it avoids levels of
870     recursion in the regex matching; (c) add a paragraph to the documentation
871     for the FullMatch() function.
873     6. The escape sequence \n was being treated as whatever was defined as
874     "newline". Not only was this contrary to the documentation, which states
875     that \n is character 10 (hex 0A), but it also went horribly wrong when
876     "newline" was defined as CRLF. This has been fixed.
878     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
879     was being set to -1 for the "end of line" case (supposedly a value that no
880     character can have). Though this value is never used (the check for end of
881     line is "zero bytes in current character"), it caused compiler complaints.
882     I've changed it to 0xffffffff.
884     8. In pcre_version.c, the version string was being built by a sequence of
885     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
886     string (as it is for production releases) called a macro with an empty
887     argument. The C standard says the result of this is undefined. The gcc
888     compiler treats it as an empty string (which was what was wanted) but it is
889     reported that Visual C gives an error. The source has been hacked around to
890     avoid this problem.
892     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
893     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
894     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
895     of them did).
897     10. Originally, pcretest opened its input and output without "b"; then I was
898     told that "b" was needed in some environments, so it was added for release
899     5.0 to both the input and output. (It makes no difference on Unix-like
900     systems.) Later I was told that it is wrong for the input on Windows. I've
901     now abstracted the modes into two macros, to make it easier to fiddle with
902     them, and removed "b" from the input mode under Windows.
904     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
906     12. Added -help and --help to pcretest as an official way of being reminded
907     of the options.
909     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
910     and pcrecpp.cc because they annoy compilers at high warning levels.
912     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
914     15. Fixed an occurrence of == in configure.ac that should have been = (shell
915     scripts are not C programs :-) and which was not noticed because it works
916     on Linux.
918     16. pcretest is supposed to handle any length of pattern and data line (as one
919     line or as a continued sequence of lines) by extending its input buffer if
920     necessary. This feature was broken for very long pattern lines, leading to
921     a string of junk being passed to pcre_compile() if the pattern was longer
922     than about 50K.
924     17. I have done a major re-factoring of the way pcre_compile() computes the
925     amount of memory needed for a compiled pattern. Previously, there was code
926     that made a preliminary scan of the pattern in order to do this. That was
927     OK when PCRE was new, but as the facilities have expanded, it has become
928     harder and harder to keep it in step with the real compile phase, and there
929     have been a number of bugs (see for example, 4 above). I have now found a
930     cunning way of running the real compile function in a "fake" mode that
931     enables it to compute how much memory it would need, while actually only
932     ever using a few hundred bytes of working memory and without too many
933     tests of the mode. This should make future maintenance and development
934     easier. A side effect of this work is that the limit of 200 on the nesting
935     depth of parentheses has been removed (though this was never a serious
936     limitation, I suspect). However, there is a downside: pcre_compile() now
937     runs more slowly than before (30% or more, depending on the pattern). I
938     hope this isn't a big issue. There is no effect on runtime performance.
940     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
941     newline (only possible for the last line of a file) and it was a
942     pattern that set a locale (followed by /Lsomething), pcretest crashed.
944     19. Added additional timing features to pcretest. (1) The -tm option now times
945     matching only, not compiling. (2) Both -t and -tm can be followed, as a
946     separate command line item, by a number that specifies the number of
947     repeats to use when timing. The default is 50000; this gives better
948     precision, but takes uncomfortably long for very large patterns.
950     20. Extended pcre_study() to be more clever in cases where a branch of a
951     subpattern has no definite first character. For example, (a*|b*)[cd] would
952     previously give no result from pcre_study(). Now it recognizes that the
953     first character must be a, b, c, or d.
955     21. There was an incorrect error "recursive call could loop indefinitely" if
956     a subpattern (or the entire pattern) that was being tested for matching an
957     empty string contained only one non-empty item after a nested subpattern.
958     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
959     incorrectly, because the \d was being skipped in the check.
961     22. The pcretest program now has a new pattern option /B and a command line
962     option -b, which is equivalent to adding /B to every pattern. This causes
963     it to show the compiled bytecode, without the additional information that
964     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
965     is the same as /B/I).
967     23. A new optimization is now able automatically to treat some sequences such
968     as a*b as a*+b. More specifically, if something simple (such as a character
969     or a simple class like \d) has an unlimited quantifier, and is followed by
970     something that cannot possibly match the quantified thing, the quantifier
971     is automatically "possessified".
973     24. A recursive reference to a subpattern whose number was greater than 39
974     went wrong under certain circumstances in UTF-8 mode. This bug could also
975     have affected the operation of pcre_study().
977     25. Realized that a little bit of performance could be had by replacing
978     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
980     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
982     27. Possessive quantifiers such as a++ were previously implemented by turning
983     them into atomic groups such as ($>a+). Now they have their own opcodes,
984     which improves performance. This includes the automatically created ones
985     from 23 above.
987     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
988     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
989     the first matched character to be a colon. This applied both to named and
990     numbered groups.
992     29. The ucpinternal.h header file was missing its idempotency #ifdef.
994     30. I was sent a "project" file called libpcre.a.dev which I understand makes
995     building PCRE on Windows easier, so I have included it in the distribution.
997     31. There is now a check in pcretest against a ridiculously large number being
998     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
999     loop, the loop is abandoned.
1001     32. Forward references to subpatterns in conditions such as (?(2)...) where
1002     subpattern 2 is defined later cause pcre_compile() to search forwards in
1003     the pattern for the relevant set of parentheses. This search went wrong
1004     when there were unescaped parentheses in a character class, parentheses
1005     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1007     33. "Subroutine" calls and backreferences were previously restricted to
1008     referencing subpatterns earlier in the regex. This restriction has now
1009     been removed.
1011     34. Added a number of extra features that are going to be in Perl 5.10. On the
1012     whole, these are just syntactic alternatives for features that PCRE had
1013     previously implemented using the Python syntax or my own invention. The
1014     other formats are all retained for compatibility.
1016     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1017     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1018     also .NET compatible.
1020     (b) A recursion or subroutine call to a named group can now be defined as
1021     (?&name) as well as (?P>name).
1023     (c) A backreference to a named group can now be defined as \k<name> or
1024     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1025     5.10, are also .NET compatible.
1027     (d) A conditional reference to a named group can now use the syntax
1028     (?(<name>) or (?('name') as well as (?(name).
1030     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1031     groups (named and numbered) that are never evaluated inline, but can be
1032     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1033     is always false. There may be only one alternative in such a group.
1035     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1036     as the simple (?(R). The condition is true only if the most recent
1037     recursion is that of the given number or name. It does not search out
1038     through the entire recursion stack.
1040     (g) The escape \gN or \g{N} has been added, where N is a positive or
1041     negative number, specifying an absolute or relative reference.
1043     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1044     some "unreachable code" warnings.
1046     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1047     things, this adds five new scripts.
1049     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1050     There were also incompatibilities regarding the handling of \Q..\E inside
1051     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1052     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1054     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1055     matches an empty string, and forcibly breaks the loop. There were bugs in
1056     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1057     against aaaa the result was just "a" rather than "aaaa", for example. Two
1058     separate and independent bugs (that affected different cases) have been
1059     fixed.
1061     39. Refactored the code to abolish the use of different opcodes for small
1062     capturing bracket numbers. This is a tidy that I avoided doing when I
1063     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1064     The new approach is not only tidier, it makes it possible to reduce the
1065     memory needed to fix the previous bug (38).
1067     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1068     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1069     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1070     mode.
1072     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1073     report.
1075     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1076     copy construction and assignment in the C++ wrapper.
1078     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1079     couple of bugs that could have given wrong results in the "--newline=crlf"
1080     case.
1082     44. Added a number of casts and did some reorganization of signed/unsigned int
1083     variables following suggestions from Dair Grant. Also renamed the variable
1084     "this" as "item" because it is a C++ keyword.
1086     45. Arranged for dftables to add
1088     #include "pcre_internal.h"
1090     to pcre_chartables.c because without it, gcc 4.x may remove the array
1091     definition from the final binary if PCRE is built into a static library and
1092     dead code stripping is activated.
1094     46. For an unanchored pattern, if a match attempt fails at the start of a
1095     newline sequence, and the newline setting is CRLF or ANY, and the next two
1096     characters are CRLF, advance by two characters instead of one.
1099 nigel 91 Version 6.7 04-Jul-06
1100     ---------------------
1102     1. In order to handle tests when input lines are enormously long, pcretest has
1103     been re-factored so that it automatically extends its buffers when
1104     necessary. The code is crude, but this _is_ just a test program. The
1105     default size has been increased from 32K to 50K.
1107     2. The code in pcre_study() was using the value of the re argument before
1108     testing it for NULL. (Of course, in any sensible call of the function, it
1109     won't be NULL.)
1111     3. The memmove() emulation function in pcre_internal.h, which is used on
1112     systems that lack both memmove() and bcopy() - that is, hardly ever -
1113     was missing a "static" storage class specifier.
1115     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1116     containing an extended class (one that cannot be represented by a bitmap
1117     because it contains high-valued characters or Unicode property items, e.g.
1118     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1119     pattern, but PCRE should not loop if you do not (it no longer does).
1120     [Detail: two cases were found: (a) a repeated subpattern containing an
1121     extended class; (b) a recursive reference to a subpattern that followed a
1122     previous extended class. It wasn't skipping over the extended class
1123     correctly when UTF-8 mode was not set.]
1125     5. A negated single-character class was not being recognized as fixed-length
1126     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1127     compile error "lookbehind assertion is not fixed length".
1129     6. The RunPerlTest auxiliary script was showing an unexpected difference
1130     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1131     write a Perl script that can interpret lines of an input file either as
1132     byte characters or as UTF-8, which is what "perltest" was being required to
1133     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1134     can't do is switch easily at run time between having the "use utf8;" pragma
1135     or not. In the end, I fudged it by using the RunPerlTest script to insert
1136     "use utf8;" explicitly for the UTF-8 tests.
1138     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1139     the end of the subject string, contrary to the documentation and to what
1140     Perl does. This was true of both matching functions. Now it matches only at
1141     the start of the subject and immediately after *internal* newlines.
1143     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1144     a pointer to an int instead of a pointer to an unsigned long int. This
1145     caused problems on 64-bit systems.
1147     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1148     instance of the 'standard' template library not being so standard".
1150     10. There was no check on the number of named subpatterns nor the maximum
1151     length of a subpattern name. The product of these values is used to compute
1152     the size of the memory block for a compiled pattern. By supplying a very
1153     long subpattern name and a large number of named subpatterns, the size
1154     computation could be caused to overflow. This is now prevented by limiting
1155     the length of names to 32 characters, and the number of named subpatterns
1156     to 10,000.
1158     11. Subpatterns that are repeated with specific counts have to be replicated in
1159     the compiled pattern. The size of memory for this was computed from the
1160     length of the subpattern and the repeat count. The latter is limited to
1161     65535, but there was no limit on the former, meaning that integer overflow
1162     could in principle occur. The compiled length of a repeated subpattern is
1163     now limited to 30,000 bytes in order to prevent this.
1165     12. Added the optional facility to have named substrings with the same name.
1167     13. Added the ability to use a named substring as a condition, using the
1168     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1169     are numbers (not recommended). Forward references are permitted.
1171     14. Added forward references in named backreferences (if you see what I mean).
1173     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1174     pattern could run off the end of the subject. For example, the pattern
1175     "(?s)(.{1,5})"8 did this with the subject "ab".
1177     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1178     PCRE_CASELESS was set when matching characters that were quantified with ?
1179     or *.
1181     17. A character class other than a single negated character that had a minimum
1182     but no maximum quantifier - for example [ab]{6,} - was not handled
1183     correctly by pce_dfa_exec(). It would match only one character.
1185     18. A valid (though odd) pattern that looked like a POSIX character
1186     class but used an invalid character after [ (for example [[,abc,]]) caused
1187     pcre_compile() to give the error "Failed: internal error: code overflow" or
1188     in some cases to crash with a glibc free() error. This could even happen if
1189     the pattern terminated after [[ but there just happened to be a sequence of
1190     letters, a binary zero, and a closing ] in the memory that followed.
1192     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1193     over the years. Originally (before any Unicode support), just the bottom 8
1194     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1195     output from "man perlunicode" includes this:
1197     The regular expression compiler produces polymorphic opcodes. That
1198     is, the pattern adapts to the data and automatically switches to
1199     the Unicode character scheme when presented with Unicode data--or
1200     instead uses a traditional byte scheme when presented with byte
1201     data.
1203     Sadly, a wide octal escape does not cause a switch, and in a string with
1204     no other multibyte characters, these octal escapes are treated as before.
1205     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1206     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1207     Unicode string.
1209     I have not perpetrated such confusion in PCRE. Up till now, it took just
1210     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1211     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1212     translate to the appropriate multibyte character.
1214     29. Applied some refactoring to reduce the number of warnings from Microsoft
1215     and Borland compilers. This has included removing the fudge introduced
1216     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1217     a warning about an unused variable.
1219     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1220     characters since release 4.0, because Perl (from release 5.004) does not.
1221     [Or at least, is documented not to: some releases seem to be in conflict
1222     with the documentation.] However, when a pattern was studied with
1223     pcre_study() and all its branches started with \s, PCRE still included VT
1224     as a possible starting character. Of course, this did no harm; it just
1225     caused an unnecessary match attempt.
1227     22. Removed a now-redundant internal flag bit that recorded the fact that case
1228     dependency changed within the pattern. This was once needed for "required
1229     byte" processing, but is no longer used. This recovers a now-scarce options
1230     bit. Also moved the least significant internal flag bit to the most-
1231     significant bit of the word, which was not previously used (hangover from
1232     the days when it was an int rather than a uint) to free up another bit for
1233     the future.
1235     23. Added support for CRLF line endings as well as CR and LF. As well as the
1236     default being selectable at build time, it can now be changed at runtime
1237     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1238     specify that it is scanning data with non-default line endings.
1240     24. Changed the definition of CXXLINK to make it agree with the definition of
1241     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1243     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1244     recursions. This makes a big different to stack usage for some patterns.
1246     26. If a subpattern containing a named recursion or subroutine reference such
1247     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1248     the space required for the compiled pattern went wrong and gave too small a
1249     value. Depending on the environment, this could lead to "Failed: internal
1250     error: code overflow at offset 49" or "glibc detected double free or
1251     corruption" errors.
1253     27. Applied patches from Google (a) to support the new newline modes and (b) to
1254     advance over multibyte UTF-8 characters in GlobalReplace.
1256     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1257     difference for some implementation of PCRE in some Windows version.
1259     29. Added some extra testing facilities to pcretest:
1261     \q<number> in a data line sets the "match limit" value
1262     \Q<number> in a data line sets the "match recursion limt" value
1263     -S <number> sets the stack size, where <number> is in megabytes
1265     The -S option isn't available for Windows.
1268 nigel 89 Version 6.6 06-Feb-06
1269     ---------------------
1271     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1272     in pcreposix.h. I have copied the definition from pcre.h.
1274     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1275     because pcre.h is no longer a built file.
1277     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1278     not normally included in the compiled code.
1281 nigel 87 Version 6.5 01-Feb-06
1282     ---------------------
1284     1. When using the partial match feature with pcre_dfa_exec(), it was not
1285     anchoring the second and subsequent partial matches at the new starting
1286     point. This could lead to incorrect results. For example, with the pattern
1287     /1234/, partially matching against "123" and then "a4" gave a match.
1289     2. Changes to pcregrep:
1291     (a) All non-match returns from pcre_exec() were being treated as failures
1292     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1293     error message is output. Some extra information is given for the
1295     probably the only errors that are likely to be caused by users (by
1296     specifying a regex that has nested indefinite repeats, for instance).
1297     If there are more than 20 of these errors, pcregrep is abandoned.
1299     (b) A binary zero was treated as data while matching, but terminated the
1300     output line if it was written out. This has been fixed: binary zeroes
1301     are now no different to any other data bytes.
1303     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1304     used to set a locale for matching. The --locale=xxxx long option has
1305     been added (no short equivalent) to specify a locale explicitly on the
1306     pcregrep command, overriding the environment variables.
1308     (d) When -B was used with -n, some line numbers in the output were one less
1309     than they should have been.
1311     (e) Added the -o (--only-matching) option.
1313     (f) If -A or -C was used with -c (count only), some lines of context were
1314     accidentally printed for the final match.
1316     (g) Added the -H (--with-filename) option.
1318     (h) The combination of options -rh failed to suppress file names for files
1319     that were found from directory arguments.
1321     (i) Added the -D (--devices) and -d (--directories) options.
1323     (j) Added the -F (--fixed-strings) option.
1325     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1327     (l) Added the --colo(u)r option.
1329     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1330     is not present by default.
1332     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1333     items such as (?R) or (?1), when the recursion could match a number of
1334     alternatives. If it matched one of the alternatives, but subsequently,
1335     outside the recursion, there was a failure, the code tried to back up into
1336     the recursion. However, because of the way PCRE is implemented, this is not
1337     possible, and the result was an incorrect result from the match.
1339     In order to prevent this happening, the specification of recursion has
1340     been changed so that all such subpatterns are automatically treated as
1341     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1343     4. I had overlooked the fact that, in some locales, there are characters for
1344     which isalpha() is true but neither isupper() nor islower() are true. In
1345     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1346     and ordfeminine) are like this. This affected the treatment of \w and \W
1347     when they appeared in character classes, but not when they appeared outside
1348     a character class. The bit map for "word" characters is now created
1349     separately from the results of isalnum() instead of just taking it from the
1350     upper, lower, and digit maps. (Plus the underscore character, of course.)
1352     5. The above bug also affected the handling of POSIX character classes such as
1353     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1354     permanent tables. Instead, the bit maps for such a class were previously
1355     created as the appropriate unions of the upper, lower, and digit bitmaps.
1356     Now they are created by subtraction from the [[:word:]] class, which has
1357     its own bitmap.
1359     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1360     It is created by subtracting the vertical space characters (\x09, \x0a,
1361     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1362     subtraction was done in the overall bitmap for a character class, meaning
1363     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1364     be recognized. This bug has been fixed.
1366     7. Patches from the folks at Google:
1368     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1369     real life, but is still worth protecting against".
1371     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1372     regular expressions".
1374     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1375     have it.
1377     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1378     "configure" and the latter not, in order to fix a problem somebody had
1379     with compiling the Arg class on HP-UX.
1381     (e) Improve the error-handling of the C++ wrapper a little bit.
1383     (f) New tests for checking recursion limiting.
1385     8. The pcre_memmove() function, which is used only if the environment does not
1386     have a standard memmove() function (and is therefore rarely compiled),
1387     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1388     returning a result (though PCRE never actually uses the result).
1390     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1391     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1392     returned instead of calling malloc() with an overflowing number that would
1393     most likely cause subsequent chaos.
1395     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1397     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1398     with this option is matched, the nmatch and pmatch options of regexec() are
1399     ignored.
1401     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1402     provided in case anyone wants to the the POSIX interface with UTF-8
1403     strings.
1405     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1406     C++ linking (needed for some HP-UX environments).
1408     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1409     (unused parameter) and in the pcre_printint() function (omitted "default"
1410     switch label when the default is to do nothing).
1412     15. Added some code to make it possible, when PCRE is compiled as a C++
1413     library, to replace subject pointers for pcre_exec() with a smart pointer
1414     class, thus making it possible to process discontinuous strings.
1416     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1417     much the same function. They were added by different people who were trying
1418     to make PCRE easy to compile on non-Unix systems. It has been suggested
1419     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1420     for compiling on Windows systems. I have therefore replaced it with
1421     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1422     defaults to "extern" for C or "extern C" for C++, which works fine on
1423     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1424     SCOPE with something explicit in config.h. In addition:
1426     (a) pcreposix.h still had just "extern" instead of either of these macros;
1427     I have replaced it with PCRE_DATA_SCOPE.
1429     (b) Functions such as _pcre_xclass(), which are internal to the library,
1430     but external in the C sense, all had PCRE_EXPORT in their definitions.
1431     This is apparently wrong for the Windows case, so I have removed it.
1432     (It makes no difference on Unix-like systems.)
1434     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1435     of recursive calls to match(). This is different to MATCH_LIMIT because
1436     that limits the total number of calls to match(), not all of which increase
1437     the depth of recursion. Limiting the recursion depth limits the amount of
1438     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1439     when PCRE is compiled, and changed at run time. A patch from Google adds
1440     this functionality to the C++ interface.
1442     18. Changes to the handling of Unicode character properties:
1444     (a) Updated the table to Unicode 4.1.0.
1446     (b) Recognize characters that are not in the table as "Cn" (undefined).
1448     (c) I revised the way the table is implemented to a much improved format
1449     which includes recognition of ranges. It now supports the ranges that
1450     are defined in UnicodeData.txt, and it also amalgamates other
1451     characters into ranges. This has reduced the number of entries in the
1452     table from around 16,000 to around 3,000, thus reducing its size
1453     considerably. I realized I did not need to use a tree structure after
1454     all - a binary chop search is just as efficient. Having reduced the
1455     number of entries, I extended their size from 6 bytes to 8 bytes to
1456     allow for more data.
1458     (d) Added support for Unicode script names via properties such as \p{Han}.
1460     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1461     matching that character.
1463     20. When matching a repeated Unicode property with a minimum greater than zero,
1464     (for example \pL{2,}), PCRE could look past the end of the subject if it
1465     reached it while seeking the minimum number of characters. This could
1466     happen only if some of the characters were more than one byte long, because
1467     there is a check for at least the minimum number of bytes.
1469     21. Refactored the implementation of \p and \P so as to be more general, to
1470     allow for more different types of property in future. This has changed the
1471     compiled form incompatibly. Anybody with saved compiled patterns that use
1472     \p or \P will have to recompile them.
1474     22. Added "Any" and "L&" to the supported property types.
1476     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1477     but give a compile time error if the value is greater than 0xff.
1479     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1480     accidentally not being installed or uninstalled.
1482     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1483     made were to insert the current release number. This seemed silly, because
1484     it made things harder for people building PCRE on systems that don't run
1485     "configure". I have turned pcre.h into a distributed file, no longer built
1486     by "configure", with the version identification directly included. There is
1487     no longer a pcre.h.in file.
1489     However, this change necessitated a change to the pcre-config script as
1490     well. It is built from pcre-config.in, and one of the substitutions was the
1491     release number. I have updated configure.ac so that ./configure now finds
1492     the release number by grepping pcre.h.
1494     26. Added the ability to run the tests under valgrind.
1497 nigel 85 Version 6.4 05-Sep-05
1498     ---------------------
1500     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1501     "--" to be printed when multiple files were scanned, even when none of the
1502     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1503     consider it to be a bug, and have restored the previous behaviour.
1505     2. A couple of code tidies to get rid of compiler warnings.
1507     3. The pcretest program used to cheat by referring to symbols in the library
1508     whose names begin with _pcre_. These are internal symbols that are not
1509     really supposed to be visible externally, and in some environments it is
1510     possible to suppress them. The cheating is now confined to including
1511     certain files from the library's source, which is a bit cleaner.
1513     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1514     file's purpose clearer.
1516     5. Reorganized pcre_ucp_findchar().
1519 nigel 83 Version 6.3 15-Aug-05
1520     ---------------------
1522     1. The file libpcre.pc.in did not have general read permission in the tarball.
1524     2. There were some problems when building without C++ support:
1526     (a) If C++ support was not built, "make install" and "make test" still
1527     tried to test it.
1529     (b) There were problems when the value of CXX was explicitly set. Some
1530     changes have been made to try to fix these, and ...
1532     (c) --disable-cpp can now be used to explicitly disable C++ support.
1534     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1535     backslash in a target when C++ was disabled. This confuses some
1536     versions of "make", apparently. Using an intermediate variable solves
1537     this. (Same for CPP_LOBJ.)
1539     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1540     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1541     necessary on certain architectures.
1543     4. Added a setting of -export-symbols-regex to the link command to remove
1544     those symbols that are exported in the C sense, but actually are local
1545     within the library, and not documented. Their names all begin with
1546     "_pcre_". This is not a perfect job, because (a) we have to except some
1547     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1548     available (and never for static libraries). I have made a note to try to
1549     find a way round (a) in the future.
1552 nigel 81 Version 6.2 01-Aug-05
1553     ---------------------
1555     1. There was no test for integer overflow of quantifier values. A construction
1556     such as {1111111111111111} would give undefined results. What is worse, if
1557     a minimum quantifier for a parenthesized subpattern overflowed and became
1558     negative, the calculation of the memory size went wrong. This could have
1559     led to memory overwriting.
1561     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1563     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1564     operating environments where this matters.
1566     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1567     PCRE options from within the C++ wrapper.
1569     5. Named capturing subpatterns were not being correctly counted when a pattern
1570     was compiled. This caused two problems: (a) If there were more than 100
1571     such subpatterns, the calculation of the memory needed for the whole
1572     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1573     back references of the form \12, where the number was greater than 9, were
1574     not recognized as back references, even though there were sufficient
1575     previous subpatterns.
1577     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1578     versions of gcc, e.g. 2.95.4.
1581 nigel 79 Version 6.1 21-Jun-05
1582     ---------------------
1584     1. There was one reference to the variable "posix" in pcretest.c that was not
1585     surrounded by "#if !defined NOPOSIX".
1587     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1588     the cross-check on the old pcre_info() function, for the benefit of the
1589     cut-down version of PCRE that is currently imported into Exim.
1591     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1592     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1593     patterns that start (?i) but I don't think that matters. The use of (?i) is
1594     just an example; this all applies to the other options as well.
1596     4. Since libtool seems to echo the compile commands it is issuing, the output
1597     from "make" can be reduced a bit by putting "@" in front of each libtool
1598     compile command.
1600     5. Patch from the folks at Google for configure.in to be a bit more thorough
1601     in checking for a suitable C++ installation before trying to compile the
1602     C++ stuff. This should fix a reported problem when a compiler was present,
1603     but no suitable headers.
1605     6. The man pages all had just "PCRE" as their title. I have changed them to
1606     be the relevant file name. I have also arranged that these names are
1607     retained in the file doc/pcre.txt, which is a concatenation in text format
1608     of all the man pages except the little individual ones for each function.
1610     7. The NON-UNIX-USE file had not been updated for the different set of source
1611     files that come with release 6. I also added a few comments about the C++
1612     wrapper.
1615 nigel 77 Version 6.0 07-Jun-05
1616     ---------------------
1618     1. Some minor internal re-organization to help with my DFA experiments.
1620     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1621     didn't matter for the library itself when fully configured, but did matter
1622     when compiling without UCP support, or within Exim, where the ucp files are
1623     not imported.
1625     3. Refactoring of the library code to split up the various functions into
1626     different source modules. The addition of the new DFA matching code (see
1627     below) to a single monolithic source would have made it really too
1628     unwieldy, quite apart from causing all the code to be include in a
1629     statically linked application, when only some functions are used. This is
1630     relevant even without the DFA addition now that patterns can be compiled in
1631     one application and matched in another.
1633     The downside of splitting up is that there have to be some external
1634     functions and data tables that are used internally in different modules of
1635     the library but which are not part of the API. These have all had their
1636     names changed to start with "_pcre_" so that they are unlikely to clash
1637     with other external names.
1639     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1640     a different (DFA) algorithm. Although it is slower than the original
1641     function, it does have some advantages for certain types of matching
1642     problem.
1644     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1645     including restarting after a partial match.
1647     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1648     defined when compiling for Windows was sent to me. I have put it into the
1649     code, though I have no means of testing or verifying it.
1651     7. Added the pcre_refcount() auxiliary function.
1653     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1654     match before or at the first newline in the subject string. In pcretest,
1655     the /f option on a pattern can be used to set this.
1657     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1658     would behave wrongly. This has been present in PCRE since release 4.0.
1660     10. A number of changes to the pcregrep command:
1662     (a) Refactored how -x works; insert ^(...)$ instead of setting
1663     PCRE_ANCHORED and checking the length, in preparation for adding
1664     something similar for -w.
1666     (b) Added the -w (match as a word) option.
1668     (c) Refactored the way lines are read and buffered so as to have more
1669     than one at a time available.
1671     (d) Implemented a pcregrep test script.
1673     (e) Added the -M (multiline match) option. This allows patterns to match
1674     over several lines of the subject. The buffering ensures that at least
1675     8K, or the rest of the document (whichever is the shorter) is available
1676     for matching (and similarly the previous 8K for lookbehind assertions).
1678     (f) Changed the --help output so that it now says
1680     -w, --word-regex(p)
1682     instead of two lines, one with "regex" and the other with "regexp"
1683     because that confused at least one person since the short forms are the
1684     same. (This required a bit of code, as the output is generated
1685     automatically from a table. It wasn't just a text change.)
1687     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1688     option but starts with a hyphen. Could be a pattern or a path name
1689     starting with a hyphen, for instance.
1691     (h) "-" can be given as a file name to represent stdin.
1693     (i) When file names are being printed, "(standard input)" is used for
1694     the standard input, for compatibility with GNU grep. Previously
1695     "<stdin>" was used.
1697     (j) The option --label=xxx can be used to supply a name to be used for
1698     stdin when file names are being printed. There is no short form.
1700     (k) Re-factored the options decoding logic because we are going to add
1701     two more options that take data. Such options can now be given in four
1702     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1704     (l) Added the -A, -B, and -C options for requesting that lines of context
1705     around matches be printed.
1707     (m) Added the -L option to print the names of files that do not contain
1708     any matching lines, that is, the complement of -l.
1710     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1711     continue to scan other files.
1713     (o) The -s option was incorrectly implemented. For compatibility with other
1714     greps, it now suppresses the error message for a non-existent or non-
1715     accessible file (but not the return code). There is a new option called
1716     -q that suppresses the output of matching lines, which was what -s was
1717     previously doing.
1719     (p) Added --include and --exclude options to specify files for inclusion
1720     and exclusion when recursing.
1722     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1723     Hopefully, it now does.
1725     12. Missing cast in pcre_study().
1727     13. Added an "uninstall" target to the makefile.
1729     14. Replaced "extern" in the function prototypes in Makefile.in with
1730     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1731     world, but is set differently for Windows.
1733     15. Added a second compiling function called pcre_compile2(). The only
1734     difference is that it has an extra argument, which is a pointer to an
1735     integer error code. When there is a compile-time failure, this is set
1736     non-zero, in addition to the error test pointer being set to point to an
1737     error message. The new argument may be NULL if no error number is required
1738     (but then you may as well call pcre_compile(), which is now just a
1739     wrapper). This facility is provided because some applications need a
1740     numeric error indication, but it has also enabled me to tidy up the way
1741     compile-time errors are handled in the POSIX wrapper.
1743     16. Added VPATH=.libs to the makefile; this should help when building with one
1744     prefix path and installing with another. (Or so I'm told by someone who
1745     knows more about this stuff than I do.)
1747     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1748     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1749     match everything, including newlines. This is not POSIX-compatible, but
1750     somebody wanted the feature. From pcretest it can be activated by using
1751     both the P and the s flags.
1753     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1755     19. libpcre.pc was being incorrectly installed as executable.
1757     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1758     it now also looks for '\r' so that it will work unmodified on Windows.
1760     21. Added Google's contributed C++ wrapper to the distribution.
1762     22. Added some untidy missing memory free() calls in pcretest, to keep
1763     Electric Fence happy when testing.
1767 nigel 75 Version 5.0 13-Sep-04
1768     ---------------------
1770     1. Internal change: literal characters are no longer packed up into items
1771     containing multiple characters in a single byte-string. Each character
1772     is now matched using a separate opcode. However, there may be more than one
1773     byte in the character in UTF-8 mode.
1775     2. The pcre_callout_block structure has two new fields: pattern_position and
1776     next_item_length. These contain the offset in the pattern to the next match
1777     item, and its length, respectively.
1779     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1780     insertion of callouts before each pattern item. Added the /C option to
1781     pcretest to make use of this.
1783     4. On the advice of a Windows user, the lines
1785     #if defined(_WIN32) || defined(WIN32)
1786     _setmode( _fileno( stdout ), 0x8000 );
1787     #endif /* defined(_WIN32) || defined(WIN32) */
1789     have been added to the source of pcretest. This apparently does useful
1790     magic in relation to line terminators.
1792     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1793     for the benefit of those environments where the "b" makes a difference.
1795     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1796     to know about it. I have put a hack into configure.in that adds in code
1797     to set GCC=yes if CC=icc. This seems to end up at a point in the
1798     generated configure script that is early enough to affect the setting of
1799     compiler options, which is what is needed, but I have no means of testing
1800     whether it really works. (The user who reported this had patched the
1801     generated configure script, which of course I cannot do.)
1803     LATER: After change 22 below (new libtool files), the configure script
1804     seems to know about icc (and also ecc). Therefore, I have commented out
1805     this hack in configure.in.
1807     7. Added support for pkg-config (2 patches were sent in).
1809     8. Negated POSIX character classes that used a combination of internal tables
1810     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1811     [[:^ascii]]. Typically, they would match almost any characters. The other
1812     POSIX classes were not broken in this way.
1814     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1815     to find the match, as PCRE was deluded into thinking that the match had to
1816     start at the start point or following a newline. The same bug applied to
1817     patterns with negative forward assertions or any backward assertions
1818     preceding ".*" at the start, unless the pattern required a fixed first
1819     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1821     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1822     starting at the last subject character, bytes beyond the end of the subject
1823     string were read.
1825     11. Renamed the variable "class" as "classbits" to make life easier for C++
1826     users. (Previously there was a macro definition, but it apparently wasn't
1827     enough.)
1829     12. Added the new field "tables" to the extra data so that tables can be passed
1830     in at exec time, or the internal tables can be re-selected. This allows
1831     a compiled regex to be saved and re-used at a later time by a different
1832     program that might have everything at different addresses.
1834     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1835     -R library as well as a -L library.
1837     14. The debugging options of pcretest (-d on the command line or D on a
1838     pattern) showed incorrect output for anything following an extended class
1839     that contained multibyte characters and which was followed by a quantifier.
1841     15. Added optional support for general category Unicode character properties
1842     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1843     support. It adds about 90K to the size of the library. The meanings of the
1844     inbuilt class escapes such as \d and \s have NOT been changed.
1846     16. Updated pcredemo.c to include calls to free() to release the memory for the
1847     compiled pattern.
1849     17. The generated file chartables.c was being created in the source directory
1850     instead of in the building directory. This caused the build to fail if the
1851     source directory was different from the building directory, and was
1852     read-only.
1854     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1855     file. No doubt somebody will tell me if they don't make sense... Also added
1856     Dan Mooney's comments about building on OpenVMS.
1858     19. Added support for partial matching via the PCRE_PARTIAL option for
1859     pcre_exec() and the \P data escape in pcretest.
1861     20. Extended pcretest with 3 new pattern features:
1863     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1864     write the compiled pattern to the file whose name is "rest-of-line".
1865     This is a straight binary dump of the data, with the saved pointer to
1866     the character tables forced to be NULL. The study data, if any, is
1867     written too. After writing, pcretest reads a new pattern.
1869     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1870     compiled pattern from the given file. There must not be any
1871     occurrences of "<" in the file name (pretty unlikely); if there are,
1872     pcretest will instead treat the initial "<" as a pattern delimiter.
1873     After reading in the pattern, pcretest goes on to read data lines as
1874     usual.
1876     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1877     and 16-bit fields in a compiled pattern, to simulate a pattern that
1878     was compiled on a host of opposite endianness.
1880     21. The pcre-exec() function can now cope with patterns that were compiled on
1881     hosts of opposite endianness, with this restriction:
1883     As for any compiled expression that is saved and used later, the tables
1884     pointer field cannot be preserved; the extra_data field in the arguments
1885     to pcre_exec() should be used to pass in a tables address if a value
1886     other than the default internal tables were used at compile time.
1888     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1889     now diagnosed as an error. Previously, most of the time, a negative number
1890     would have been treated as zero, but if in addition "ovector" was passed as
1891     NULL, a crash could occur.
1893     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1894     new versions from the libtool 1.5 distribution (the last one is a copy of
1895     a file called libtool.m4). This seems to have fixed the need to patch
1896     "configure" to support Darwin 1.3 (which I used to do). However, I still
1897     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1898     workstation).
1900     24. Changed the PCRE licence to be the more standard "BSD" licence.
1903 nigel 73 Version 4.5 01-Dec-03
1904     ---------------------
1906     1. There has been some re-arrangement of the code for the match() function so
1907     that it can be compiled in a version that does not call itself recursively.
1908     Instead, it keeps those local variables that need separate instances for
1909     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1910     needs to "recurse". Keeping track of where control must go is done by means
1911     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1912     hide most of the details from the main code, and operates only if
1913     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1914     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1915     operating.
1917     To make it easier for callers to provide specially tailored get/free
1918     functions for this usage, two new functions, pcre_stack_malloc, and
1919     pcre_stack_free, are used. They are always called in strict stacking order,
1920     and the size of block requested is always the same.
1922     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1923     PCRE has been compiled to use the stack or the heap for recursion. The
1924     -C option of pcretest uses this to show which version is compiled.
1926     A new data escape \S, is added to pcretest; it causes the amounts of store
1927     obtained and freed by both kinds of malloc/free at match time to be added
1928     to the output.
1930     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1931     what's available on my current Linux desktop machine.
1933     3. When matching a UTF-8 string, the test for a valid string at the start has
1934     been extended. If start_offset is not zero, PCRE now checks that it points
1935     to a byte that is the start of a UTF-8 character. If not, it returns
1936     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1937     this is necessary because there may be backward assertions in the pattern.
1938     When matching the same subject several times, it may save resources to use
1939     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1941     4. The code for checking the validity of UTF-8 strings has been tightened so
1942     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1943     containing "overlong sequences".
1945     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1946     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1947     should have been "&", but it just so happened that all the cases this let
1948     through by mistake were picked up later in the function.
1950     6. I had used a variable called "isblank" - this is a C99 function, causing
1951     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1953     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1954     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1955     so the version is shown; (c) stop "make test" echoing "./RunTest".
1957     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1959     9. The prototype for memmove() for systems that don't have it was using
1960     size_t, but the inclusion of the header that defines size_t was later. I've
1961     moved the #includes for the C headers earlier to avoid this.
1963     10. Added some adjustments to the code to make it easier to compiler on certain
1964     special systems:
1966     (a) Some "const" qualifiers were missing.
1967     (b) Added the macro EXPORT before all exported functions; by default this
1968     is defined to be empty.
1969     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1970     that it reads its output file name as an argument instead of writing
1971     to the standard output and assuming this can be redirected.
1973     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1974     class containing characters with values greater than 255, PCRE compilation
1975     went into a loop.
1977     12. A recursive reference to a subpattern that was within another subpattern
1978     that had a minimum quantifier of zero caused PCRE to crash. For example,
1979     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1980     recursion. If the recursively-called subpattern itself had a zero repeat,
1981     that was OK.
1983     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1984     buffer into which it was copied (for escape processing) was still set at
1985     1024, so long lines caused crashes.
1987     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1988     "internal error: code overflow...". This applied to any character class
1989     that was followed by a possessive quantifier.
1991     15. Modified the Makefile to add libpcre.la as a prerequisite for
1992     libpcreposix.la because I was told this is needed for a parallel build to
1993     work.
1995     16. If a pattern that contained .* following optional items at the start was
1996     studied, the wrong optimizing data was generated, leading to matching
1997     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1998     matching string must start with a or b or c. The correct conclusion for
1999     this pattern is that a match can start with any character.
2002 nigel 71 Version 4.4 13-Aug-03
2003     ---------------------
2005     1. In UTF-8 mode, a character class containing characters with values between
2006     127 and 255 was not handled correctly if the compiled pattern was studied.
2007     In fixing this, I have also improved the studying algorithm for such
2008     classes (slightly).
2010     2. Three internal functions had redundant arguments passed to them. Removal
2011     might give a very teeny performance improvement.
2013     3. Documentation bug: the value of the capture_top field in a callout is *one
2014     more than* the number of the hightest numbered captured substring.
2016     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2017     in incorrectly linking with a previously installed version. They now link
2018     explicitly with libpcre.la.
2020     5. configure.in no longer needs to recognize Cygwin specially.
2022     6. A problem in pcre.in for Windows platforms is fixed.
2024     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2025     pcretest, it used to include the size of the study block as part of its
2026     output. Unfortunately, the structure contains a field that has a different
2027     size on different hardware architectures. This meant that the tests that
2028     showed this size failed. As the block is currently always of a fixed size,
2029     this information isn't actually particularly useful in pcretest output, so
2030     I have just removed it.
2032     8. Three pre-processor statements accidentally did not start in column 1.
2033     Sadly, there are *still* compilers around that complain, even though
2034     standard C has not required this for well over a decade. Sigh.
2036     9. In pcretest, the code for checking callouts passed small integers in the
2037     callout_data field, which is a void * field. However, some picky compilers
2038     complained about the casts involved for this on 64-bit systems. Now
2039     pcretest passes the address of the small integer instead, which should get
2040     rid of the warnings.
2042     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2043     both compile and run time, and gives an error if an invalid UTF-8 sequence
2044     is found. There is a option for disabling this check in cases where the
2045     string is known to be correct and/or the maximum performance is wanted.
2047     11. In response to a bug report, I changed one line in Makefile.in from
2049     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2050     to
2051     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2053     to look similar to other lines, but I have no way of telling whether this
2054     is the right thing to do, as I do not use Windows. No doubt I'll get told
2055     if it's wrong...
2058 nigel 69 Version 4.3 21-May-03
2059     ---------------------
2061     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2062     Makefile.
2064     2. Some refactoring to improve the quality of the code:
2066     (i) The utf8_table... variables are now declared "const".
2068     (ii) The code for \cx, which used the "case flipping" table to upper case
2069     lower case letters, now just substracts 32. This is ASCII-specific,
2070     but the whole concept of \cx is ASCII-specific, so it seems
2071     reasonable.
2073     (iii) PCRE was using its character types table to recognize decimal and
2074     hexadecimal digits in the pattern. This is silly, because it handles
2075     only 0-9, a-f, and A-F, but the character types table is locale-
2076     specific, which means strange things might happen. A private
2077     table is now used for this - though it costs 256 bytes, a table is
2078     much faster than multiple explicit tests. Of course, the standard
2079     character types table is still used for matching digits in subject
2080     strings against \d.
2082     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2083     ending in _t are). So I've renamed it as ESC_tee.
2085     3. The first argument for regexec() in the POSIX wrapper should have been
2086     defined as "const".
2088     4. Changed pcretest to use malloc() for its buffers so that they can be
2089     Electric Fenced for debugging.
2091     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2092     to read one or more bytes before the start of the subject string. Often this
2093     had no effect on PCRE's behaviour, but in some circumstances it could
2094     provoke a segmentation fault.
2096     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2097     to try to read one or more bytes before the start of the subject string.
2099     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2100     UTF-8 support could misbehave in various ways if the subject string
2101     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2102     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2103     back over UTF-8 characters.)
2106 nigel 67 Version 4.2 14-Apr-03
2107     ---------------------
2109     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2111     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2112     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2113     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2114     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2115     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2116     and BUILD_EXEEXT
2117     Note: automatic setting of the BUILD variables is not yet working
2118     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2119     compile-time but not at link-time
2120     [LINK]: use for linking executables only
2121     make different versions for Windows and non-Windows
2122     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2123     libraries
2124     [LINK_FOR_BUILD]: new variable
2125     [OBJEXT]: use throughout
2126     [EXEEXT]: use throughout
2127     <winshared>: new target
2128     <wininstall>: new target
2129     <dftables.o>: use native compiler
2130     <dftables>: use native linker
2131     <install>: handle Windows platform correctly
2132     <clean>: ditto
2133     <check>: ditto
2134     copy DLL to top builddir before testing
2136     As part of these changes, -no-undefined was removed again. This was reported
2137     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2138     in any case.
2140     3. Some tidies to get rid of compiler warnings:
2142     . In the match_data structure, match_limit was an unsigned long int, whereas
2143     match_call_count was an int. I've made them both unsigned long ints.
2145     . In pcretest the fact that a const uschar * doesn't automatically cast to
2146     a void * provoked a warning.
2148     . Turning on some more compiler warnings threw up some "shadow" variables
2149     and a few more missing casts.
2151     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2152     option, a class that contained a single character with a value between 128
2153     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2155     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2156     option, a class that contained several characters, but with at least one
2157     whose value was between 128 and 255 caused PCRE to crash.
2160 nigel 65 Version 4.1 12-Mar-03
2161     ---------------------
2162 nigel 63
2163 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2164     needed, and a string in dftables.c that was longer than standard compilers are
2165     required to support.
2167     2. Compiling with Sun's compiler found a few more places where the code could
2168     be tidied up in order to avoid warnings.
2170     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2171     first of these names is deprecated in the latest Autoconf in favour of the name
2172     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2173     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2174     analogy I have changed it to CFLAGS_FOR_BUILD.
2176     4. Added -no-undefined to the linking command in the Makefile, because this is
2177     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2178     linking step for the pcreposix library.
2180     5. PCRE was failing to diagnose the case of two named groups with the same
2181     name.
2183     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2184     literal character that is needed in the subject for a match, and scans along to
2185     ensure that it is present before embarking on the full matching process. This
2186     saves time in cases of nested unlimited repeats that are never going to match.
2187     Problem: the scan can take a lot of time if the subject is very long (e.g.
2188     megabytes), thus penalizing straightforward matches. It is now done only if the
2189     amount of subject to be scanned is less than 1000 bytes.
2191     7. A lesser problem with the same optimization is that it was recording the
2192     first character of an anchored pattern as "needed", thus provoking a search
2193     right along the subject, even when the first match of the pattern was going to
2194     fail. The "needed" character is now not set for anchored patterns, unless it
2195     follows something in the pattern that is of non-fixed length. Thus, it still
2196     fulfils its original purpose of finding quick non-matches in cases of nested
2197     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2200     Version 4.0 17-Feb-03
2201     ---------------------
2203 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2204     extended to the end of string, PCRE compiled incorrect data. This could lead to
2205     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2207     2. Moved to autoconf 2.53 and libtool 1.4.2.
2209     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2210     the special perltest8 script is no longer needed - all the tests can be run
2211     from a single perltest script.
2213     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2214     by \s. It has now been removed in PCRE. This means it isn't recognized as
2215     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2216     class [:space:] *does* include VT, thereby creating a mess.
2218     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2219     space and tab.
2221     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2222     its new features into the main test script, reducing the number of scripts.
2224     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2225     were backward compatible, and made the (?i) apply to the whole pattern, as if
2226     /i were given. Now it behaves more logically, and applies the option setting
2227     only to what follows. PCRE has been changed to follow suit. However, if it
2228     finds options settings right at the start of the pattern, it extracts them into
2229     the global options, as before. Thus, they show up in the info data.
2231     8. Added support for the \Q...\E escape sequence. Characters in between are
2232     treated as literals. This is slightly different from Perl in that $ and @ are
2233     also handled as literals inside the quotes. In Perl, they will cause variable
2234     interpolation. Note the following examples:
2236     Pattern PCRE matches Perl matches
2238     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2239     \Qabc\$xyz\E abc\$xyz abc\$xyz
2240     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2242     For compatibility with Perl, \Q...\E sequences are recognized inside character
2243     classes as well as outside them.
2245     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2246     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2247     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2248     signed/unsigned warnings.
2250     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2251     option for pcretest, so I've replaced it by a simple function that does just
2252     that job.
2254     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2255     "pcregrep -".
2257     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2258     Java package. This provides some syntactic sugar for simple cases of what my
2259     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2260     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2261     item, you can use this simplified notation. Note that only makes sense with
2262     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2263     greediness, whatever the setting of the PCRE_UNGREEDY option.
2265     13. A change of greediness default within a pattern was not taking effect at
2266     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2267     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2268     was abstracted outside.
2270     14. PCRE now supports the \G assertion. It is true when the current matching
2271     position is at the start point of the match. This differs from \A when the
2272     starting offset is non-zero. Used with the /g option of pcretest (or similar
2273     code), it works in the same way as it does for Perl's /g option. If all
2274     alternatives of a regex begin with \G, the expression is anchored to the start
2275     match position, and the "anchored" flag is set in the compiled expression.
2277     15. Some bugs concerning the handling of certain option changes within patterns
2278     have been fixed. These applied to options other than (?ims). For example,
2279     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2280     been the other way round. Some of this was related to change 7 above.
2282     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2283     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2284     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2285     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2287     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2288     mode. Unlike ".", it always matches newline, whatever the setting of
2289     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2290     assertions. Perl allows it, but it doesn't (in general) work because it can't
2291     calculate the length of the lookbehind. At least, that's the case for Perl
2292     5.8.0 - I've been told they are going to document that it doesn't work in
2293     future.
2295     18. Added an error diagnosis for escapes that PCRE does not support: these are
2296     \L, \l, \N, \P, \p, \U, \u, and \X.
2298     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2299     reading past the end of the pattern in cases such as /[abcd/.
2301     20. PCRE was getting more memory than necessary for patterns with classes that
2302     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2304     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2305     compiling PCRE for use with Virtual Pascal.
2307     22. Small fix to the Makefile to make it work properly if the build is done
2308     outside the source tree.
2310     23. Added a new extension: a condition to go with recursion. If a conditional
2311     subpattern starts with (?(R) the "true" branch is used if recursion has
2312     happened, whereas the "false" branch is used only at the top level.
2314     24. When there was a very long string of literal characters (over 255 bytes
2315     without UTF support, over 250 bytes with UTF support), the computation of how
2316     much memory was required could be incorrect, leading to segfaults or other
2317     strange effects.
2319     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2320     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2321     there was a subsequent back reference to those brackets. This meant that, for
2322     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2323     possible to check for precisely this case. All we can do is abandon the
2324     optimization if .* occurs inside capturing brackets when there are any back
2325     references whatsoever. (See below for a better fix that came later.)
2327     26. The handling of the optimization for finding the first character of a
2328     non-anchored pattern, and for finding a character that is required later in the
2329     match were failing in some cases. This didn't break the matching; it just
2330     failed to optimize when it could. The way this is done has been re-implemented.
2332     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2334     28. Added a new feature that provides some of the functionality that Perl
2335     provides with (?{...}). The facility is termed a "callout". The way it is done
2336     in PCRE is for the caller to provide an optional function, by setting
2337     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2338     global variable. By default it is unset, which disables all calling out. To get
2339     the function called, the regex must include (?C) at appropriate points. This
2340     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2341     This provides a means of identifying different callout points. When PCRE
2342     reaches such a point in the regex, if pcre_callout has been set, the external
2343     function is called. It is provided with data in a structure called
2344     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2345     matching continues; if it returns a non-zero value, the match at the current
2346     point fails. However, backtracking will occur if possible. [This was changed
2347     later and other features added - see item 49 below.]
2349     29. pcretest is upgraded to test the callout functionality. It provides a
2350     callout function that displays information. By default, it shows the start of
2351     the match and the current position in the text. There are some new data escapes
2352     to vary what happens:
2354     \C+ in addition, show current contents of captured substrings
2355     \C- do not supply a callout function
2356     \C!n return 1 when callout number n is reached
2357     \C!n!m return 1 when callout number n is reached for the mth time
2359     30. If pcregrep was called with the -l option and just a single file name, it
2360     output "<stdin>" if a match was found, instead of the file name.
2362     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2363     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2364     pcre_exec(). This saves a malloc/free per call. The default value of
2365     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2366     when configuring.
2368     32. The default maximum size of a compiled pattern is 64K. There have been a
2369     few cases of people hitting this limit. The code now uses macros to handle the
2370     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2371     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2372     configuring. Tests 2 and 5 work only with 2-byte links because they output
2373     debugging information about compiled patterns.
2375     33. Internal code re-arrangements:
2377     (a) Moved the debugging function for printing out a compiled regex into
2378     its own source file (printint.c) and used #include to pull it into
2379     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2380     separate copies.
2382     (b) Defined the list of op-code names for debugging as a macro in
2383     internal.h so that it is next to the definition of the opcodes.
2385     (c) Defined a table of op-code lengths for simpler skipping along compiled
2386     code. This is again a macro in internal.h so that it is next to the
2387     definition of the opcodes.
2389     34. Added support for recursive calls to individual subpatterns, along the
2390     lines of Robin Houston's patch (but implemented somewhat differently).
2392     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2393     allow it to read and process whole directories in Win32. This code was
2394     contributed by Lionel Fourquaux; it has not been tested by me.
2396     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2397     used to name a group. Names consist of alphanumerics and underscores, and must
2398     be unique. Back references use the syntax (?P=name) and recursive calls use
2399     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2400     numbers. The function pcre_fullinfo() can be used after compilation to extract
2401     a name/number map. There are three relevant calls:
2403     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2404     PCRE_INFO_NAMECOUNT yields the number of entries
2405     PCRE_INFO_NAMETABLE yields a pointer to the map.
2407     The map is a vector of fixed-size entries. The size of each entry depends on
2408     the length of the longest name used. The first two bytes of each entry are the
2409     group number, most significant byte first. There follows the corresponding
2410     name, zero terminated. The names are in alphabetical order.
2412     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2413     case instead of 255. Making it the same both with and without UTF-8 support
2414     means that the same test output works with both.
2416     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2417     calling malloc() with a zero argument.
2419     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2420     optimization. I've improved things by keeping a bitmap of backreferences with
2421     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2422     fact referenced, the optimization can be applied. It is unlikely that a
2423     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2424     the match to follow \n) will appear inside brackets with a number greater than
2425     31, but if it does, any back reference > 31 suppresses the optimization.
2427     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2428     of disabling numbered capturing parentheses. Any opening parenthesis that is
2429     not followed by ? behaves as if it were followed by ?: but named parentheses
2430     can still be used for capturing (and they will acquire numbers in the usual
2431     way).
2433     41. Redesigned the return codes from the match() function into yes/no/error so
2434     that errors can be passed back from deep inside the nested calls. A malloc
2435     failure while inside a recursive subpattern call now causes the
2436     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2438     42. It is now possible to set a limit on the number of times the match()
2439     function is called in a call to pcre_exec(). This facility makes it possible to
2440     limit the amount of recursion and backtracking, though not in a directly
2441     obvious way, because the match() function is used in a number of different
2442     circumstances. The count starts from zero for each position in the subject
2443     string (for non-anchored patterns). The default limit is, for compatibility, a
2444     large number, namely 10 000 000. You can change this in two ways:
2446     (a) When configuring PCRE before making, you can use --with-match-limit=n
2447     to set a default value for the compiled library.
2449     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2450     a different value is set. See 45 below.
2452     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2454     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2455     of things that can be changed at compile time. The first argument specifies
2456     what is wanted and the second points to where the information is to be placed.
2457     The current list of available information is:
2461     The output is an integer that is set to one if UTF-8 support is available;
2462     otherwise it is set to zero.
2466     The output is an integer that it set to the value of the code that is used for
2467     newline. It is either LF (10) or CR (13).
2471     The output is an integer that contains the number of bytes used for internal
2472     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2476     The output is an integer that contains the threshold above which the POSIX
2477     interface uses malloc() for output vectors. See item 31 above.
2481     The output is an unsigned integer that contains the default limit of the number
2482     of match() calls in a pcre_exec() execution. See 42 above.
2484     44. pcretest has been upgraded by the addition of the -C option. This causes it
2485     to extract all the available output from the new pcre_config() function, and to
2486     output it. The program then exits immediately.
2488     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2489     order to support additional features. One way would have been to define
2490     pcre_exec2() (for example) with extra arguments, but this would not have been
2491     extensible, and would also have required all calls to the original function to
2492     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2493     is used for passing in "extra" data from pcre_study().
2495     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2496     contains the following fields:
2498     flags a bitmap indicating which of the following fields are set
2499     study_data opaque data from pcre_study()
2500     match_limit a way of specifying a limit on match() calls for a specific
2501     call to pcre_exec()
2502     callout_data data for callouts (see 49 below)
2504     The flag bits are also defined in pcre.h, and are
2510     The pcre_study() function now returns one of these new pcre_extra blocks, with
2511     the actual study data pointed to by the study_data field, and the
2512     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2513     before. That is, this change is entirely upwards-compatible and requires no
2514     change to existing code.
2516     If you want to pass in additional data to pcre_exec(), you can either place it
2517     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2518     block.
2520     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2521     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2522     times with different match limits, until it finds the minimum value needed for
2523     pcre_exec() to complete. The value is then output. This can be instructive; for
2524     most simple matches the number is quite small, but for pathological cases it
2525     gets very large very quickly.
2527     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2528     returns the size of the data block pointed to by the study_data field in a
2529     pcre_extra block, that is, the value that was passed as the argument to
2530     pcre_malloc() when PCRE was getting memory in which to place the information
2531     created by pcre_study(). The fourth argument should point to a size_t variable.
2532     pcretest has been extended so that this information is shown after a successful
2533     pcre_study() call when information about the compiled regex is being displayed.
2535     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2536     because what follows is always an absolute path. (Later: it turns out that this
2537     is more than cosmetic for MinGW, because it doesn't like empty path
2538     components.)
2540     49. Some changes have been made to the callout feature (see 28 above):
2542     (i) A callout function now has three choices for what it returns:
2544     0 => success, carry on matching
2545     > 0 => failure at this point, but backtrack if possible
2546     < 0 => serious error, return this value from pcre_exec()
2548     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2549     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2550     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2551     use by callout functions. It will never be used by PCRE itself.
2553     (ii) The pcre_extra structure (see 45 above) has a void * field called
2554     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2555     pcre_callout_block structure has a field of the same name. The contents of
2556     the field passed in the pcre_extra structure are passed to the callout
2557     function in the corresponding field in the callout block. This makes it
2558     easier to use the same callout-containing regex from multiple threads. For
2559     testing, the pcretest program has a new data escape
2561     \C*n pass the number n (may be negative) as callout_data
2563     If the callout function in pcretest receives a non-zero value as
2564     callout_data, it returns that value.
2566     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2567     there were some redundant $(CFLAGS) in commands that are now specified as
2568     $(LINK), which already includes $(CFLAGS).
2570     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2571     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2572     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2573     one-byte characters throughout. Note that case-insensitive matching applies
2574     only to characters whose values are less than 256. PCRE doesn't support the
2575     notion of cases for higher-valued characters.
2577     (i) A character class whose characters are all within 0-255 is handled as
2578     a bit map, and the map is inverted for negative classes. Previously, a
2579     character > 255 always failed to match such a class; however it should
2580     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2582     (ii) A negated character class with a single character < 255 is coded as
2583     "not this character" (OP_NOT). This wasn't working properly when the test
2584     character was multibyte, either singly or repeated.
2586     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2587     mode, for example: \x{100}{2,3}.
2589     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2590     singly or repeated) now correctly test multibyte characters. However,
2591     PCRE doesn't recognize any characters with values greater than 255 as
2592     digits, spaces, or word characters. Such characters always match \D, \S,
2593     and \W, and never match \d, \s, or \w.
2595     (v) Classes may now contain characters and character ranges with values
2596     greater than 255. For example: [ab\x{100}-\x{400}].
2598     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2599     PCRE in UTF-8 mode.
2601     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2602     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2603     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2604     value.)
2606     53. The single man page has become too large. I have therefore split it up into
2607     a number of separate man pages. These also give rise to individual HTML pages;
2608     these are now put in a separate directory, and there is an index.html page that
2609     lists them all. Some hyperlinking between the pages has been installed.
2611     54. Added convenience functions for handling named capturing parentheses.
2613     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2614     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2615     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2616     are faulted.
2618     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2619     calling configure. These values are used when compiling the dftables.c program
2620     which is run to generate the source of the default character tables. They
2621     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2622     you will need to set these values.
2624     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2627     Version 3.9 02-Jan-02
2628 nigel 61 ---------------------
2630     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2632     2. If --disable-static was given, the building process failed when trying to
2633     build pcretest and pcregrep. (For some reason it was using libtool to compile
2634     them, which is not right, as they aren't part of the library.)
2637 nigel 59 Version 3.8 18-Dec-01
2638     ---------------------
2640     1. The experimental UTF-8 code was completely screwed up. It was packing the
2641     bytes in the wrong order. How dumb can you get?
2644 nigel 57 Version 3.7 29-Oct-01
2645     ---------------------
2647     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2648     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2649     this didn't happen under Solaris 8, where I normally test things.
2651 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2652     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2653     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2654     this fix an hour or so after the initial 3.7 release.)
2655 nigel 57
2656 nigel 59
2657 nigel 55 Version 3.6 23-Oct-01
2658     ---------------------
2660     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2661     offsets passed as NULL with zero offset count.
2663     2. The config.guess and config.sub files had not been updated when I moved to
2664     the latest autoconf.
2667 nigel 53 Version 3.5 15-Aug-01
2668     ---------------------
2669 nigel 5
2670 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2671     had been forgotten.
2673     2. By using declared but undefined structures, we can avoid using "void"
2674     definitions in pcre.h while keeping the internal definitions of the structures
2675     private.
2677     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2678     user point of view, this means that both static and shared libraries are built
2679     by default, but this can be individually controlled. More of the work of
2680     handling this static/shared cases is now inside libtool instead of PCRE's make
2681     file.
2683     4. The pcretest utility is now installed along with pcregrep because it is
2684     useful for users (to test regexs) and by doing this, it automatically gets
2685     relinked by libtool. The documentation has been turned into a man page, so
2686     there are now .1, .txt, and .html versions in /doc.
2688     5. Upgrades to pcregrep:
2689     (i) Added long-form option names like gnu grep.
2690     (ii) Added --help to list all options with an explanatory phrase.
2691     (iii) Added -r, --recursive to recurse into sub-directories.
2692     (iv) Added -f, --file to read patterns from a file.
2694     6. pcre_exec() was referring to its "code" argument before testing that
2695     argument for NULL (and giving an error if it was NULL).
2697     7. Upgraded Makefile.in to allow for compiling in a different directory from
2698     the source directory.
2700     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2701     options bits, the pointer it was passed was to an int instead of to an unsigned
2702     long int. This mattered only on 64-bit systems.
2704     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2705     generated) instead of pcre.in, which it its source. Also made the same change
2706     in several of the .c files.
2708     10. A new release of gcc defines printf() as a macro, which broke pcretest
2709     because it had an ifdef in the middle of a string argument for printf(). Fixed
2710     by using separate calls to printf().
2712     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2713     script, to force use of CR or LF instead of \n in the source. On non-Unix
2714     systems, the value can be set in config.h.
2716     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2717     absolute limit. Changed the text of the error message to make this clear, and
2718     likewise updated the man page.
2720     13. The limit of 99 on the number of capturing subpatterns has been removed.
2721     The new limit is 65535, which I hope will not be a "real" limit.
2724 nigel 51 Version 3.4 22-Aug-00
2725     ---------------------
2727     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2729     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2732 nigel 49 Version 3.3 01-Aug-00
2733     ---------------------
2735     1. If an octal character was given, but the value was greater than \377, it
2736     was not getting masked to the least significant bits, as documented. This could
2737     lead to crashes in some systems.
2739     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2740     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2742     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2743     These just pass their arguments on to (pcre_free)(), but they are provided
2744     because some uses of PCRE bind it to non-C systems that can call its functions,
2745     but cannot call free() or pcre_free() directly.
2747     4. Add "make test" as a synonym for "make check". Corrected some comments in
2748     the Makefile.
2750     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2751     Makefile.
2753     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2754     command called pgrep for grepping around the active processes.
2756     7. Added the beginnings of support for UTF-8 character strings.
2758     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2759     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2760     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2761     out for the ar command.)
2764 nigel 47 Version 3.2 12-May-00
2765     ---------------------
2767     This is purely a bug fixing release.
2769     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2770     of ZA. This was just one example of several cases that could provoke this bug,
2771     which was introduced by change 9 of version 2.00. The code for breaking
2772     infinite loops after an iteration that matches an empty string was't working
2773     correctly.
2775     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2776     when matched against abbab (for example). After matching an empty string, it
2777     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2778     caused it to match further down the string than it should.
2780     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2781     was there because it doesn't seem to be needed, and it causes trouble on some
2782     systems, as it is not a Standard C header. It has been removed.
2784     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2785     were reported on the Macintosh. The changes were from
2787     while ((c = *(++ptr)) != 0 && c != '\n');
2788     to
2789     while ((c = *(++ptr)) != 0 && c != '\n') ;
2791     Totally extraordinary, but if that's what it takes...
2793     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2794     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2795     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2796     assumes the way PCRE uses memmove() (always moving upwards).
2798     6. PCRE is being used in one environment where strchr() is not available. There
2799     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2800     faster code anyway.
2803 nigel 45 Version 3.1 09-Feb-00
2804     ---------------------
2806     The only change in this release is the fixing of some bugs in Makefile.in for
2807     the "install" target:
2809     (1) It was failing to install pcreposix.h.
2811     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2814 nigel 43 Version 3.0 01-Feb-00
2815     ---------------------
2816 nigel 41
2817     1. Add support for the /+ modifier to perltest (to output $` like it does in
2818     pcretest).
2820     2. Add support for the /g modifier to perltest.
2822     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2823     matches null strings.
2825     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2826     pattern. Perl treats empty patterns specially - it reuses the most recent
2827     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2828     effect.
2830     5. The POSIX interface was broken in that it was just handing over the POSIX
2831     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2832     required a bigger vector, with some working space on the end. This means that
2833     the POSIX wrapper now has to get and free some memory, and copy the results.
2835 nigel 43 6. Added some simple autoconf support, placing the test data and the
2836     documentation in separate directories, re-organizing some of the
2837     information files, and making it build pcre-config (a GNU standard). Also added
2838     libtool support for building PCRE as a shared library, which is now the
2839     default.
2840 nigel 41
2841 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2842     09 are not valid octal constants. Single digits will be used for minor values
2843     less than 10.
2845     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2846     existing programs that set these in the POSIX interface can use PCRE without
2847     modification.
2849     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2850     return all that pcre_info() returns, plus additional data. The pcre_info()
2851     function is retained for compatibility, but is considered to be obsolete.
2853     10. Added experimental recursion feature (?R) to handle one common case that
2854     Perl 5.6 will be able to do with (?p{...}).
2856     11. Added support for POSIX character classes like [:alpha:], which Perl is
2857     adopting.
2860 nigel 39 Version 2.08 31-Aug-99
2861     ----------------------
2863     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2864     trying to match at the startoffset position, but instead was moving forward to
2865     the next newline as if a previous match had failed.
2867     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2868     and could get into a loop if a null string was matched other than at the start
2869     of the subject.
2871     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2872     be distinguished at compile time, and for completeness also added PCRE_DATE.
2874     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2875     in GnuWin32 environments.
2878 nigel 37 Version 2.07 29-Jul-99
2879     ----------------------
2881     1. The documentation is now supplied in plain text form and HTML as well as in
2882     the form of man page sources.
2884     2. C++ compilers don't like assigning (void *) values to other pointer types.
2885     In particular this affects malloc(). Although there is no problem in Standard
2886     C, I've put in casts to keep C++ compilers happy.
2888     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2889     should be (const char *).
2891     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2892     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2893     However, I haven't made this a standard facility. The documentation doesn't
2894     mention it, and the Makefile doesn't support it.
2896     5. The Makefile now contains an "install" target, with editable destinations at
2897     the top of the file. The pcretest program is not installed.
2899     6. pgrep -V now gives the PCRE version number and date.
2901     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2902     causing the entire string to be ignored, instead of just the last character.
2904     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2905     non-matching string, it can take a very, very long time, even for strings of
2906     quite modest length, because of the nested recursion. PCRE now does better in
2907     some of these cases. It does this by remembering the last required literal
2908     character in the pattern, and pre-searching the subject to ensure it is present
2909     before running the real match. In other words, it applies a heuristic to detect
2910     some types of certain failure quickly, and in the above example, if presented
2911     with a string that has no trailing " it gives "no match" very quickly.
2913     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2914     other alternatives are tried instead.
2917 nigel 35 Version 2.06 09-Jun-99
2918     ----------------------
2920     1. Change pcretest's output for amount of store used to show just the code
2921     space, because the remainder (the data block) varies in size between 32-bit and
2922     64-bit systems.
2924     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2925     start matching at. This allows lookbehinds to work when searching for multiple
2926     occurrences in a string.
2928     3. Added additional options to pcretest for testing multiple occurrences:
2930     /+ outputs the rest of the string that follows a match
2931     /g loops for multiple occurrences, using the new startoffset argument
2932     /G loops for multiple occurrences by passing an incremented pointer
2934     4. PCRE wasn't doing the "first character" optimization for patterns starting
2935     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2936     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2937     the letter 'x'. On long subject strings, this gives a significant speed-up.
2940 nigel 33 Version 2.05 21-Apr-99
2941     ----------------------
2943     1. Changed the type of magic_number from int to long int so that it works
2944     properly on 16-bit systems.
2946     2. Fixed a bug which caused patterns starting with .* not to work correctly
2947     when the subject string contained newline characters. PCRE was assuming
2948     anchoring for such patterns in all cases, which is not correct because .* will
2949     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2950     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2951     must be retried after every newline in the subject.
2954 nigel 31 Version 2.04 18-Feb-99
2955     ----------------------
2957     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2958     computation of the store needed to hold the pattern was incorrect (too large).
2959     If such patterns were nested a few deep, this could multiply and become a real
2960     problem.
2962     2. Added /M option to pcretest to show the memory requirement of a specific
2963     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2965     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2966     compiled in such a way that the backtracking after subsequent failure was
2967     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2968     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2971 nigel 29 Version 2.03 02-Feb-99
2972     ----------------------
2974     1. Fixed typo and small mistake in man page.
2976 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2977     LICENCE file containing the conditions.
2978 nigel 29
2979     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2980     Perl, that is the internal \ allows the delimiter to be included in the
2981     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2982     the final delimiter, add \ to the end of the pattern (to test the error).
2984     4. Added the convenience functions for extracting substrings after a successful
2985     match. Updated pcretest to make it able to test these functions.
2988 nigel 27 Version 2.02 14-Jan-99
2989     ----------------------
2991     1. Initialized the working variables associated with each extraction so that
2992     their saving and restoring doesn't refer to uninitialized store.
2994     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2995     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2996     fix the problem.
2998     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2999     calls, and wasn't printing the correct value for compiling calls. Increased the
3000     default value of LOOPREPEAT, and the number of significant figures in the
3001     times.
3003     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3005     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3006     a building problem on Windows NT with a FAT file system.
3009 nigel 25 Version 2.01 21-Oct-98
3010     ----------------------
3012     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3013     to character tables built by pcre_maketables() in the current locale. If NULL
3014     is passed, the default tables are used.
3017 nigel 23 Version 2.00 24-Sep-98
3018 nigel 21 ----------------------
3020 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3021     it any more.
3023     2. Allow quantification of (?>) groups, and make it work correctly.
3025     3. The first character computation wasn't working for (?>) groups.
3027     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3028     end of the subject) and add 5.005's \z, which really does match only at the
3029     very end of the subject.
3031     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3033     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3034     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3035     localized options. All options to pcre_study() were also removed.
3037     7. Add other new features from 5.005:
3039     $(?<= positive lookbehind
3040     $(?<! negative lookbehind
3041     (?imsx-imsx) added the unsetting capability
3042     such a setting is global if at outer level; local otherwise
3043     (?imsx-imsx:) non-capturing groups with option setting
3044     (?(cond)re|re) conditional pattern matching
3046     A backreference to itself in a repeated group matches the previous
3047     captured string.
3049     8. General tidying up of studying (both automatic and via "study")
3050     consequential on the addition of new assertions.
3052     9. As in 5.005, unlimited repeated groups that could match an empty substring
3053     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3054     runtime if any iteration does actually match an empty substring.
3056     10. Include the RunTest script in the distribution.
3058     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3059     discrepancies, some of which were old and were also with respect to 5.004. They
3060     have now been fixed.
3063     Version 1.09 28-Apr-98
3064     ----------------------
3066 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3067     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3068     program crashes, or just wrong answers. This did not apply to negated classes
3069     containing more than one character, or to minima other than one.
3072 nigel 19 Version 1.08 27-Mar-98
3073     ----------------------
3075     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3077     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3078     latter must appear before anything that relies on it in the pattern.
3081 nigel 17 Version 1.07 16-Feb-98
3082     ----------------------
3084     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3085     repeat of a potentially empty string).
3088 nigel 15 Version 1.06 23-Jan-98
3089     ----------------------
3091     1. Added Markus Oberhumer's little patches for C++.
3093     2. Literal strings longer than 255 characters were broken.
3096 nigel 13 Version 1.05 23-Dec-97
3097     ----------------------
3099     1. Negated character classes containing more than one character were failing if
3100     PCRE_CASELESS was set at run time.
3103 nigel 11 Version 1.04 19-Dec-97
3104     ----------------------
3106     1. Corrected the man page, where some "const" qualifiers had been omitted.
3108     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3109     input syntax.
3111     3. Fixed memory leak which occurred when a regex with back references was
3112     matched with an offsets vector that wasn't big enough. The temporary memory
3113     that is used in this case wasn't being freed if the match failed.
3115     4. Tidied pcretest to ensure it frees memory that it gets.
3117     5. Temporary memory was being obtained in the case where the passed offsets
3118     vector was exactly big enough.
3120     6. Corrected definition of offsetof() from change 5 below.
3122     7. I had screwed up change 6 below and broken the rules for the use of
3123     setjmp(). Now fixed.
3126 nigel 9 Version 1.03 18-Dec-97
3127     ----------------------
3129     1. A erroneous regex with a missing opening parenthesis was correctly
3130     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3131     on some systems.
3133     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3134     it was reported that one broken compiler failed on the former because "code" is
3135     also an independent variable.
3137     3. The erroneous regex a[]b caused an array overrun reference.
3139     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3140     fail on data ending with that character. (It was going on too far, and checking
3141     the next character, typically a binary zero.) This was specific to the
3142     optimized code for single-character negative classes.
3144     5. Added a contributed patch from the TIN world which does the following:
3146     + Add an undef for memmove, in case the the system defines a macro for it.
3148     + Add a definition of offsetof(), in case there isn't one. (I don't know
3149     the reason behind this - offsetof() is part of the ANSI standard - but
3150     it does no harm).
3152     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3153     most of the places where whitespace preceded '#'. I have given up and
3154     allowed the remaining 2 cases to be at the margin.
3156     + Rename some variables in pcre to eliminate shadowing. This seems very
3157     pedantic, but does no harm, of course.
3159     6. Moved the call to setjmp() into its own function, to get rid of warnings
3160     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3162     7. Constructs such as \d{8,} were compiling into the equivalent of
3163 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3164 nigel 9 outcome, but in this particular case used more store than had been allocated,
3165     which caused the bug to be discovered because it threw up an internal error.
3167     8. The debugging code in both pcre and pcretest for outputting the compiled
3168     form of a regex was going wrong in the case of back references followed by
3169     curly-bracketed repeats.
3172 nigel 7 Version 1.02 12-Dec-97
3173     ----------------------
3175     1. Typos in pcre.3 and comments in the source fixed.
3177     2. Applied a contributed patch to get rid of places where it used to remove
3178     'const' from variables, and fixed some signed/unsigned and uninitialized
3179     variable warnings.
3181     3. Added the "runtest" target to Makefile.
3183     4. Set default compiler flag to -O2 rather than just -O.
3186 nigel 5 Version 1.01 19-Nov-97
3187     ----------------------
3189     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3190     like /([ab]*)*/, that is, for classes with more than one character in them.
3192     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3193     as /((?>a*))*/ (a PCRE_EXTRA facility).
3196     Version 1.00 18-Nov-97
3197     ----------------------
3199     1. Added compile-time macros to support systems such as SunOS4 which don't have
3200     memmove() or strerror() but have other things that can be used instead.
3202     2. Arranged that "make clean" removes the executables.
3205 nigel 3 Version 0.99 27-Oct-97
3206     ----------------------
3208     1. Fixed bug in code for optimizing classes with only one character. It was
3209     initializing a 32-byte map regardless, which could cause it to run off the end
3210     of the memory it had got.
3212     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3215     Version 0.98 22-Oct-97
3216     ----------------------
3218     1. Fixed bug in code for handling temporary memory usage when there are more
3219     back references than supplied space in the ovector. This could cause segfaults.
3222     Version 0.97 21-Oct-97
3223     ----------------------
3225     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3227     2. Optimized negated single characters not to use a bit map.
3229     3. Brought error texts together as macro definitions; clarified some of them;
3230     fixed one that was wrong - it said "range out of order" when it meant "invalid
3231     escape sequence".
3233     4. Changed some char * arguments to const char *.
3235     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3237     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3238     pcretest.
3241     Version 0.96 16-Oct-97
3242     ----------------------
3244     1. Added a simple "pgrep" utility to the distribution.
3246     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3247     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3248     where "ddd" means "one or more decimal digits".
3250     3. Fixed serious bug. If a pattern had a back reference, but the call to
3251     pcre_exec() didn't supply a large enough ovector to record the related
3252     identifying subpattern, the match always failed. PCRE now remembers the number
3253     of the largest back reference, and gets some temporary memory in which to save
3254     the offsets during matching if necessary, in order to ensure that
3255     backreferences always work.
3257     4. Increased the compatibility with Perl in a number of ways:
3259     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3260     to request this handling. The option can be set at compile or exec time.
3262     (b) $ matches before a terminating newline by default; an option
3263     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3264     mode). The option can be set at compile or exec time.
3266     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3267     the same as Perl's. If the decimal number it represents is less than 10
3268     or there aren't that many previous left capturing parentheses, an octal
3269     escape is read. Inside a character class, it's always an octal escape,
3270     even if it is a single digit.
3272     (d) An escaped but undefined alphabetic character is taken as a literal,
3273     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3274     escapes.
3276     (e) {0} is now permitted. (The previous item is removed from the compiled
3277     pattern).
3279     5. Changed all the names of code files so that the basic parts are no longer
3280     than 10 characters, and abolished the teeny "globals.c" file.
3282     6. Changed the handling of character classes; they are now done with a 32-byte
3283     bit map always.
3285     7. Added the -d and /D options to pcretest to make it possible to look at the
3286     internals of compilation without having to recompile pcre.
3289     Version 0.95 23-Sep-97
3290     ----------------------
3292     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3293     \x20 at the start of a run of normal characters. These were being treated as
3294     real characters, instead of the source characters being re-checked.
3297     Version 0.94 18-Sep-97
3298     ----------------------
3300     1. The functions are now thread-safe, with the caveat that the global variables
3301     containing pointers to malloc() and free() or alternative functions are the
3302     same for all threads.
3304     2. Get pcre_study() to generate a bitmap of initial characters for non-
3305     anchored patterns when this is possible, and use it if passed to pcre_exec().
3308     Version 0.93 15-Sep-97
3309     ----------------------
3311     1. /(b)|(:+)/ was computing an incorrect first character.
3313     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3314     but not actually doing anything yet.
3316     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3317     as Perl does (e.g. [-az] or [az-]).
3319     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3320     all possible positions.
3322     5. Split up into different modules to avoid including unneeded functions in a
3323     compiled binary. However, compile and exec are still in one module. The "study"
3324     function is split off.
3326     6. The character tables are now in a separate module whose source is generated
3327     by an auxiliary program - but can then be edited by hand if required. There are
3328     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3329     toupper() in the code.
3331     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3332     make them global. Abolish the function for setting them, as the caller can now
3333     set them directly.
3336     Version 0.92 11-Sep-97
3337     ----------------------
3339     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3340     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3342     2. Caseless matching was not working in character classes if the characters in
3343     the pattern were in upper case.
3345     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3347     4. Make PCRE_ANCHORED public and accept as a compile option.
3349     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3350     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3351     pass them.
3353     6. Give an error if bad option bits passed at compile or run time.
3355     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3356     pcretest to cause it to pass that flag.
3358     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3359     options, and the first character, if set.
3361     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3364     Version 0.91 10-Sep-97
3365     ----------------------
3367     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3368     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3370     2. PCRE was looping on encountering an indefinitely repeated back reference to
3371     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3372     Perl does - treats the match as successful.
3374     ****


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