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Revision 341 - (hide annotations) (download)
Sat Apr 19 16:41:04 2008 UTC (7 years ago) by ph10
File size: 155078 byte(s)
Fix DFA (?!) bug; add support for JavaScript empty classes.

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


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