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Revision 349 - (hide annotations) (download)
Wed Jul 2 18:42:11 2008 UTC (6 years, 9 months ago) by ph10
File size: 156588 byte(s)
Preliminary patch for upgraded Unicode Property support.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 349 Version 8.0 02 Jul-08
5     ---------------------
7     1. Replaced UCP searching code with optimized version as implemented for Ad
8     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9     stage table and inline lookup instead of a function, giving speed ups of 2
10     to 5 times on some simple patterns that I tested. Permission was given to
11     distribute the MultiStage2.py script that generates the tables (it's not in
12     the tarball, but is in the Subversion repository).
15 ph10 347 Version 7.7 07-May-08
16 ph10 321 ---------------------
18     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
19 ph10 345 a string to a long long, pretend we don't even have a long long." This is
20 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
21 ph10 345
22 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
23     pre-7.6 versions, which defined a global no_arg variable instead of putting
24 ph10 332 it in the RE class. (See also #8 below.)
25 ph10 345
26     3. Remove a line of dead code, identified by coverity and reported by Nuno
27     Lopes.
29 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
30 ph10 321
31 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
32 ph10 345 of files, instead of just to the final components.
34 ph10 324 (2) If there was more than one level of directory, the subdirectories were
35     skipped unless they satisfied the include/exclude conditions. This is
36     inconsistent with GNU grep (and could even be seen as contrary to the
37     pcregrep specification - which I improved to make it absolutely clear).
38     The action now is always to scan all levels of directory, and just
39     apply the include/exclude patterns to regular files.
40 ph10 345
41 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
42 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
44 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
45 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
46 ph10 326 doesn't support NULs in patterns.
47 ph10 345
48     7. Added some missing "const"s to declarations of static tables in
49     pcre_compile.c and pcre_dfa_exec.c.
51 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
52 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
53 ph10 345 first patch. And a third patch - this was a messy problem.)
54 ph10 321
55 ph10 345 9. Applied Craig's patch to remove the use of push_back().
57 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
58     matching function regexec().
59 ph10 345
60     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
61     which, however, unlike Perl's \g{...}, are subroutine calls, not back
62 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
63     Oniguruma does).
64 ph10 345
65     12. Previously, a group with a zero repeat such as (...){0} was completely
66 ph10 335 omitted from the compiled regex. However, this means that if the group
67     was called as a subroutine from elsewhere in the pattern, things went wrong
68 ph10 345 (an internal error was given). Such groups are now left in the compiled
69     pattern, with a new opcode that causes them to be skipped at execution
70 ph10 335 time.
71 ph10 345
72 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
73     to the way PCRE behaves:
74 ph10 345
75 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
76 ph10 345
77     (b) A back reference to an unmatched subpattern matches an empty string
78 ph10 336 (Perl fails the current match path).
79 ph10 345
80 ph10 341 (c) A data ] in a character class must be notated as \] because if the
81 ph10 345 first data character in a class is ], it defines an empty class. (In
82 ph10 341 Perl it is not possible to have an empty class.) The empty class []
83     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
84     The negative empty class [^] matches any one character, independently
85     of the DOTALL setting.
86 ph10 345
87     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
88 ph10 340 non-existent subpattern following a character class starting with ']' and
89     containing () gave an internal compiling error instead of "reference to
90     non-existent subpattern". Fortunately, when the pattern did exist, the
91 ph10 345 compiled code was correct. (When scanning forwards to check for the
92 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
93 ph10 345 the class, so got the count wrong. When actually compiling, the reference
94 ph10 340 was subsequently set up correctly.)
95 ph10 345
96 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
97 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
98     other assertions are supported. I have made pcre_dfa_exec() support
99     (*FAIL).
101 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
102 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
103     cannot be changed at match time, I realized I could make a small
104     improvement to matching performance by compiling OP_ALLANY instead of
105     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
106     on the OP_ANY path.
108     17. Compiling pcretest on Windows with readline support failed without the
109 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
110 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
112 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
113 ph10 345 ncurses library to be included for pcretest when ReadLine support is
114     requested, but also to allow for it to be overridden. This patch came from
115     Daniel Bergström.
116 ph10 347
117 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
118 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
119     any errors with the current Unicode tables. Thanks to Peter Kankowski for
120     spotting this.
121 ph10 324
122 ph10 332
123 ph10 319 Version 7.6 28-Jan-08
124 ph10 300 ---------------------
126 ph10 302 1. A character class containing a very large number of characters with
127     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
128     overflow.
129 ph10 309
130     2. Patch to cut out the "long long" test in pcrecpp_unittest when
131     HAVE_LONG_LONG is not defined.
133 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
134 ph10 304 bring them up to date and include new features. This patch includes:
135 ph10 309
136 ph10 304 - Fixed PH's badly added libz and libbz2 support.
137     - Fixed a problem with static linking.
138 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
139 ph10 304 - Fixed dftables problem and added an option.
140     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
142     - Added readline support for pcretest.
143 ph10 309 - Added an listing of the option settings after cmake has run.
145 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
146     "pcre.dll" under mingw when using Configure/Make. I added stuff to
147     Makefile.am that cause it to include this special target, without
148     affecting anything else. Note that the same mingw target plus all
149     the other distribution libraries and programs are now supported
150     when configuring with CMake (see 6 below) instead of with
151     Configure/Make.
152 ph10 309
153 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
154     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
155 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
156     solves the problem, but it does no harm.
157 ph10 313
158 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
159 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
160 ph10 314 with CMake, and also correct the comment about stack recursion.
161 ph10 313
162 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
163 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
164     of a program that users should build themselves after PCRE is installed, so
165     building it automatically is not really right. What is more, it gave
166 ph10 312 trouble in some build environments.
167 ph10 300
168 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
169 ph10 308
170 ph10 319
171 ph10 298 Version 7.5 10-Jan-08
172 ph10 263 ---------------------
174     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
175     values in parens when parsing an RE using the C++ wrapper."
176 ph10 286
177 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
178     Characters greater than 255 were excluded from the class instead of being
179     included.
180 ph10 286
181     3. The same bug as (2) above applied to negated POSIX classes such as
182 ph10 265 [:^space:].
183 ph10 286
184 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
185     defined or documented. It seems to have been a typo for PCRE_STATIC, so
186 ph10 286 I have changed it.
188 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
189 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
190     first named subpattern whose name started with "a" (in other words, the
191 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
192     expected" is now given for (?&) (a zero-length name), and this patch also
193     makes it give the same error for \k'' (previously it complained that that
194     was a reference to a non-existent subpattern).
195 ph10 286
196 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
197 ph10 286 this is right because (?- can be followed by option settings as well as by
198 ph10 269 digits. I have, however, made the messages clearer.
199 ph10 286
200 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
201     than the number used in the conditional) now cause a compile-time error.
202     This is actually not compatible with Perl, which accepts such patterns, but
203     treats the conditional as always being FALSE (as PCRE used to), but it
204     seems to me that giving a diagnostic is better.
205 ph10 286
206 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
207 ph10 275 and messages.
208 ph10 286
209     9. Fix two occurrences of "backslash" in comments that should have been
210     "backspace".
212     10. Remove two redundant lines of code that can never be obeyed (their function
213     was moved elsewhere).
215     11. The program that makes PCRE's Unicode character property table had a bug
216     which caused it to generate incorrect table entries for sequences of
217 ph10 277 characters that have the same character type, but are in different scripts.
218 ph10 286 It amalgamated them into a single range, with the script of the first of
219 ph10 277 them. In other words, some characters were in the wrong script. There were
220     thirteen such cases, affecting characters in the following ranges:
221 ph10 286
222 ph10 277 U+002b0 - U+002c1
223     U+0060c - U+0060d
224 ph10 286 U+0061e - U+00612
225 ph10 277 U+0064b - U+0065e
226     U+0074d - U+0076d
227     U+01800 - U+01805
228     U+01d00 - U+01d77
229     U+01d9b - U+01dbf
230     U+0200b - U+0200f
231     U+030fc - U+030fe
232     U+03260 - U+0327f
233     U+0fb46 - U+0fbb1
234     U+10450 - U+1049d
235 ph10 286
236 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
237     compatible with GNU grep in that, if there was more than one match in a
238     line, it showed only the first of them. It now behaves in the same way as
239     GNU grep.
240 ph10 286
241     13. If the -o and -v options were combined for pcregrep, it printed a blank
242     line for every non-matching line. GNU grep prints nothing, and pcregrep now
243     does the same. The return code can be used to tell if there were any
244     non-matching lines.
246 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
248     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
249 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
250 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
251     and both kinds of lookbehind were skipped).
253 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
254 ph10 284 inclusion of <windows.h> to before rather than after the definition of
255     INVALID_FILE_ATTRIBUTES (patch from David Byron).
256 ph10 263
257 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
258 ph10 286 character property caused pcre_compile() to compile bad code, which led at
259     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
260     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
261     caused the error; without that there was no problem.
262 ph10 263
263 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
264 ph10 286
265 ph10 289 19. Added --enable-pcretest-libreadline.
266 ph10 286
267 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
268 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
269 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
270     later patch that removed the other one (the right fix) and added unit tests
271     that check the return values (which was not done before).
272 ph10 292
273 ph10 291 21. Several CMake things:
274 ph10 287
275 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
276 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
277 ph10 288
278 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
279     linked with the newly-built libraries, not previously installed ones.
280 ph10 291
282 ph10 298
283     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
284     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
285     UTF-8 newline character). The key issue is that the pattern starts .*;
286     this means that the match must be either at the beginning, or after a
287     newline. The bug was in the code for advancing after a failed match and
288     checking that the new position followed a newline. It was not taking
289 ph10 294 account of UTF-8 characters correctly.
290 ph10 298
291     23. PCRE was behaving differently from Perl in the way it recognized POSIX
292     character classes. PCRE was not treating the sequence [:...:] as a
293     character class unless the ... were all letters. Perl, however, seems to
294     allow any characters between [: and :], though of course it rejects as
295     unknown any "names" that contain non-letters, because all the known class
296     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
297     for example, whereas PCRE did not - it did not recognize a POSIX character
298     class. This seemed a bit dangerous, so the code has been changed to be
299     closer to Perl. The behaviour is not identical to Perl, because PCRE will
300     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
301     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
302     Perl does, and where it didn't before.
304 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
305     Windows environments %n is disabled by default.
306 ph10 292
308 ph10 260 Version 7.4 21-Sep-07
309 ph10 230 ---------------------
311     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
312 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
313     LF". That isn't really right - the whole point of the change was to try to
314     help when there was an actual mention of one of the two characters. So now
315     the change happens only if \r or \n (or a literal CR or LF) character is
316 ph10 230 encountered.
317 ph10 231
318     2. The 32-bit options word was also used for 6 internal flags, but the numbers
319     of both had grown to the point where there were only 3 bits left.
320     Fortunately, there was spare space in the data structure, and so I have
321     moved the internal flags into a new 16-bit field to free up more option
322 ph10 230 bits.
323 ph10 231
324     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
325     but did not set the internal JCHANGED flag - either of these is enough to
326     control the way the "get" function works - but the PCRE_INFO_JCHANGED
327     facility is supposed to tell if (?J) was ever used, so now (?J) at the
328 ph10 230 start sets both bits.
330 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
331     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
332 ph10 230
333 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
335     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
336 ph10 233 compatibility, even though it is no longer used.
337 ph10 243
338     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
339 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
340 ph10 259 windows.h file is present (where different names are used). [This was
341 ph10 257 reversed later after testing - see 16 below.]
342 ph10 243
343     8. Changed all #include <config.h> to #include "config.h". There were also
344 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
345 ph10 243
346 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
347 ph10 243 sequence off the lines that it output.
349     10. It was pointed out to me that arrays of string pointers cause lots of
350     relocations when a shared library is dynamically loaded. A technique of
351     using a single long string with a table of offsets can drastically reduce
352     these. I have refactored PCRE in four places to do this. The result is
353 ph10 240 dramatic:
354 ph10 243
355 ph10 240 Originally: 290
356     After changing UCP table: 187
357 ph10 243 After changing error message table: 43
358 ph10 240 After changing table of "verbs" 36
359     After changing table of Posix names 22
360 ph10 243
361 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
362 ph10 247
363 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
364 ph10 247 unicode-properties was also set.
366 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
367 ph10 231
368 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
369     checked only for CRLF.
370 ph10 233
371 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
373 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
374 ph10 253
375 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
376 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
377     entirely. This removes changes made in 7 above.
378 ph10 256
379 ph10 261 17. The CMake files have been updated, and there is now more information about
380     building with CMake in the NON-UNIX-USE document.
381 ph10 257
382 ph10 261
383 ph10 228 Version 7.3 28-Aug-07
384 ph10 157 ---------------------
386 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
387     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
388     brackets there is not right, since it causes compilers to look for an
389     installed pcre.h, not the version that is in the source that is being
390     compiled (which of course may be different). I have changed it back to:
391 ph10 197
392 ph10 189 #include "pcre.h"
393 ph10 197
394     I have a vague recollection that the change was concerned with compiling in
395     different directories, but in the new build system, that is taken care of
396     by the VPATH setting the Makefile.
398 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
399     when the subject happened to end in the byte 0x85 (e.g. if the last
400     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
401     characters but of course it shouldn't be taken as a newline when it is part
402     of another character. The bug was that, for an unlimited repeat of . in
403     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
404     characters when looking for a newline.
405 ph10 197
406     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
408     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
409     in debug output.
411 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
412     long printing in the pcrecpp unittest when running under MinGW.
413 ph10 189
414 ph10 197 6. ESC_K was left out of the EBCDIC table.
415 ph10 189
416 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
417     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
418     limit also applies to "virtual nesting" when a pattern is recursive, and in
419     this case 1000 isn't so big. I have been able to remove this limit at the
420     expense of backing off one optimization in certain circumstances. Normally,
421     when pcre_exec() would call its internal match() function recursively and
422     immediately return the result unconditionally, it uses a "tail recursion"
423     feature to save stack. However, when a subpattern that can match an empty
424     string has an unlimited repetition quantifier, it no longer makes this
425     optimization. That gives it a stack frame in which to save the data for
426     checking that an empty string has been matched. Previously this was taken
427     from the 1000-entry workspace that had been reserved. So now there is no
428     explicit limit, but more stack is used.
429 ph10 189
430 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
431     syntax that is required for Windows, and which was going wrong for the
432     pcreposix and pcrecpp parts of the library. These were overlooked when this
433     problem was solved for the main library.
434 ph10 197
435 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
436     the size of patterns that contain repeated groups with explicit upper
437     limits. As the maximum quantifier is 65535, the maximum group length was
438     set at 30,000 so that the product of these two numbers did not overflow a
439     32-bit integer. However, it turns out that people want to use groups that
440     are longer than 30,000 bytes (though not repeat them that many times).
441     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
442     made it possible to implement the integer overflow checks in a much more
443     dynamic way, which I have now done. The artificial limitation on group
444     length has been removed - we now have only the limit on the total length of
445     the compiled pattern, which depends on the LINK_SIZE setting.
446 ph10 208
447     10. Fixed a bug in the documentation for get/copy named substring when
448     duplicate names are permitted. If none of the named substrings are set, the
449     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
450     empty string.
452     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
453     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
454     because the ] is interpreted as the first data character and the
455     terminating ] is not found. PCRE has been made compatible with Perl in this
456     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
457     cause memory overwriting.
459 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
460     string has been matched (to stop an infinite loop). It was not recognizing
461 ph10 208 a conditional subpattern that could match an empty string if that
462 ph10 206 subpattern was within another subpattern. For example, it looped when
463 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
464 ph10 206 condition was not nested. This bug has been fixed.
465 ph10 208
466 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
467     past the start of the subject in the presence of bytes with the top bit
468     set, for example "\x8aBCD".
469 ph10 211
470 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
471     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
472 ph10 200
473 ph10 211 14. Optimized (?!) to (*FAIL).
474 ph10 202
475 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
476     This restricts code points to be within the range 0 to 0x10FFFF, excluding
477     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
478     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
479     does: it's just the validity check that is more restrictive.
480 ph10 220
481     16. Inserted checks for integer overflows during escape sequence (backslash)
482     processing, and also fixed erroneous offset values for syntax errors during
483     backslash processing.
485 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
486 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
488 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
489     caused an overrun.
490 ph10 220
491     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
492     something other than just ASCII characters) inside a group that had an
493     unlimited repeat caused a loop at compile time (while checking to see
494     whether the group could match an empty string).
496 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
497     [\P{Any}] did so. (Error in the code for printing property names.)
498 ph10 210
499 ph10 220 21. An orphan \E inside a character class could cause a crash.
501     22. A repeated capturing bracket such as (A)? could cause a wild memory
502 ph10 218 reference during compilation.
503 ph10 220
504     23. There are several functions in pcre_compile() that scan along a compiled
505     expression for various reasons (e.g. to see if it's fixed length for look
506 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
507 ph10 220 present in the pattern. These operators have additional parameters compared
508     with \d, etc, and these were not being taken into account when moving along
509 ph10 218 the compiled data. Specifically:
510 ph10 220
511     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
512     length.
514     (b) An item such as \pL+ within a repeated group could cause crashes or
515 ph10 218 loops.
516 ph10 220
517 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
518 ph10 220 "reference to non-existent subpattern" error.
520 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
522 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
523 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
524 ph10 211
525 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
526 ph10 218
527 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
528 ph10 223 character were causing crashes (broken optimization).
529 ph10 227
530 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
531 ph10 227 \p or \P) caused a compile-time loop.
533 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
534     break. For example, the unstudied pattern [\r\n]A does not match the string
535     "\r\nA" because change 7.0/46 below moves the current point on by two
536     characters after failing to match at the start. However, the pattern \nA
537 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
538     the same is true. There doesn't seem any very clean way out of this, but
539     what I have chosen to do makes the common cases work: PCRE now takes note
540     of whether there can be an explicit match for \r or \n anywhere in the
541     pattern, and if so, 7.0/46 no longer applies. As part of this change,
542     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
543     pattern has explicit CR or LF references.
544 ph10 222
545 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
546 ph10 223
547 ph10 227
548 ph10 189 Version 7.2 19-Jun-07
549     ---------------------
551 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
552     which is apparently normally available under Windows.
553 ph10 159
554     2. Re-jig the pcregrep tests with different newline settings in an attempt
555     to make them independent of the local environment's newline setting.
556 ph10 157
557 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
558 ph10 165
559 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
560     was not 2, because the output contained actual offsets. The recent new
561 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
562     usable with all link sizes.
564 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
565     stack recursion. This gives a massive performance boost under BSD, but just
566 ph10 165 a small improvement under Linux. However, it saves one field in the frame
567 ph10 164 in all cases.
568 ph10 172
569 ph10 166 6. Added more features from the forthcoming Perl 5.10:
570 ph10 172
571 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
572     recursion call. It refers to the nth most recently opened parentheses.
573 ph10 172
574 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
575 ph10 172 to be opened parentheses.
577     (c) Conditions that refer to capturing parentheses can be specified
578 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
579 ph10 172
580 ph10 168 (d) \K resets the start of the current match so that everything before
581 ph10 172 is not part of it.
583 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
584 ph10 172
585 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
586 ph10 172 reference syntax.
587 ph10 182
588 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
589 ph10 182 alternative starts with the same number.
590 ph10 172
591 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
593 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
596     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
597     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
598 ph10 170 for detecting groups that can match an empty string.
599 ph10 159
600 ph10 172 9. A pattern with a very large number of alternatives (more than several
601     hundred) was running out of internal workspace during the pre-compile
602     phase, where pcre_compile() figures out how much memory will be needed. A
603     bit of new cunning has reduced the workspace needed for groups with
604     alternatives. The 1000-alternative test pattern now uses 12 bytes of
605     workspace instead of running out of the 4096 that are available.
606 ph10 182
607 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
608 ph10 172
609 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
610     The report of the bug said:
611 ph10 182
612 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
613     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
614 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
615 ph10 185
616 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
617 ph10 185 it matched the wrong number of bytes.
618 ph10 172
619 ph10 179
620 ph10 155 Version 7.1 24-Apr-07
621 ph10 98 ---------------------
623 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
624 ph10 122 that is more "standard", making use of automake and other Autotools. There
625 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
626     on this.
627 ph10 111
628     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
629     for recursive directory scanning broke on some systems because the files
630     are not scanned in any specific order and on different systems the order
631     was different. A call to "sort" has been inserted into RunGrepTest for the
632     approprate test as a short-term fix. In the longer term there may be an
633 ph10 100 alternative.
634 ph10 111
635 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
636 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
637     people do their own conversions for various reasons). The problems
638     concerned the use of low-level troff macros .br and .in. I have therefore
639     removed all such uses from the man pages (some were redundant, some could
640 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
641     HTML has been updated to handle .nf/.fi and to complain if it encounters
642     .br or .in.
643 ph10 111
644 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
645 ph10 123 arranged for config.h to be included in the distribution, with the name
646 ph10 111 config.h.generic, for the benefit of those who have to compile without
647     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
649     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
650     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
651 ph10 127 makevp.bat for the current PCRE, using the additional files
652 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
653 ph10 111
654     6. A Windows user reported a minor discrepancy with test 2, which turned out
655     to be caused by a trailing space on an input line that had got lost in his
656 ph10 102 copy. The trailing space was an accident, so I've just removed it.
657 ph10 111
658 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
659 ph10 111 that is needed.
661 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
662     as "const" (a) because they are and (b) because it helps the PHP
663     maintainers who have recently made a script to detect big data structures
664 ph10 111 in the php code that should be moved to the .rodata section. I remembered
665     to update Builducptable as well, so it won't revert if ucptable.h is ever
666 ph10 105 re-created.
667 ph10 111
668     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
669 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
670 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
671     support is not required. This saves 1.5-2K of code, which is important in
672 ph10 107 some applications.
673 ph10 111
674 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
675 ph10 111 so as not to refer to the tables, even though these functions will never be
676     called when UTF-8 support is disabled. Otherwise there are problems with a
677     shared library.
679 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
681     (a) It was defining its arguments as char * instead of void *.
683 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
684     a long time ago when I wrote it, but is no longer the case.
686 ph10 118 The emulated memove() is provided for those environments that have neither
687 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
688 ph10 118 is clearly not the case, as these two bugs were recently reported.
689 ph10 123
690 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
691 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
692     pages, and it removes trailing spaces from listed files. It also creates
693     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
694     case, it wraps all the #defines with #ifndefs. This script should be run
695 ph10 111 before "make dist".
696 ph10 123
697 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
698     with Unicode property support.
699 ph10 123
700     (a) For a maximizing quantifier, if the two different cases of the
701     character were of different lengths in their UTF-8 codings (there are
702     some cases like this - I found 11), and the matching function had to
703 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
704     were both the same length.
705 ph10 123
706     (b) When PCRE was configured to use the heap rather than the stack for
707     recursion during matching, it was not correctly preserving the data for
708     the other case of a UTF-8 character when checking ahead for a match
709     while processing a minimizing repeat. If the check also involved
710 ph10 115 matching a wide character, but failed, corruption could cause an
711     erroneous result when trying to check for a repeat of the original
712     character.
713 ph10 123
714 ph10 116 13. Some tidying changes to the testing mechanism:
715 ph10 98
716 ph10 116 (a) The RunTest script now detects the internal link size and whether there
717     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
718 ph10 123 values substituted by "configure". (The RunGrepTest script already did
719     this for UTF-8.) The configure.ac script no longer substitutes the
720     relevant variables.
722 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
723     with length and offset values. This means that the output is different
724     for different internal link sizes. Test 2 is skipped for link sizes
725     other than 2 because of this, bypassing the problem. Unfortunately,
726     there was also a test in test 3 (the locale tests) that used /B and
727 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
728     I have added a new /Z option to pcretest that replaces the length and
729     offset values with spaces. This is now used to make test 3 independent
730 ph10 122 of link size. (Test 2 will be tidied up later.)
731 ph10 123
732     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
733 ph10 122 segmentation fault instead of returning the appropriate error message.
734 ph10 134
735 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
736 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
737     This doesn't seem right; it now treats the CRLF combination as the line
738     ending, and so does not match in that case. It's only a pattern such as ^$
739     that would hit this one: something like ^ABC$ would have failed after \r
740     and then tried again after \r\n.
742 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
743 ph10 134 in an attempt to make files that differ only in their line terminators
744     compare equal. This works on Linux.
745 ph10 142
746 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
747     as it exited. This is now fixed, thanks to valgrind.
748 ph10 142
749 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
750 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
751     was because its rules for how to advance for /g after matching an empty
752 ph10 143 string at the end of a line did not allow for this case. They now check for
753     it specially.
754 ph10 150
755     20. pcretest is supposed to handle patterns and data of any length, by
756     extending its buffers when necessary. It was getting this wrong when the
757 ph10 147 buffer for a data line had to be extended.
758 ph10 150
759 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
760 ph10 150 CRLF as a newline sequence.
761 ph10 152
762 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
763 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
764     I have nevertheless tidied it up.
765 ph10 111
766 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
767 ph10 123
768 ph10 153 24. Added a man page for pcre-config.
769 ph10 152
770 ph10 153
771 nigel 93 Version 7.0 19-Dec-06
772     ---------------------
774     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
775     moving to gcc 4.1.1.
777     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
778     sys/time.h, which is documented as needed for this function. It doesn't
779     seem to matter on Linux, but it showed up on some releases of OS X.
781     3. It seems that there are systems where bytes whose values are greater than
782     127 match isprint() in the "C" locale. The "C" locale should be the
783     default when a C program starts up. In most systems, only ASCII printing
784     characters match isprint(). This difference caused the output from pcretest
785     to vary, making some of the tests fail. I have changed pcretest so that:
787     (a) When it is outputting text in the compiled version of a pattern, bytes
788     other than 32-126 are always shown as hex escapes.
790     (b) When it is outputting text that is a matched part of a subject string,
791     it does the same, unless a different locale has been set for the match
792     (using the /L modifier). In this case, it uses isprint() to decide.
794     4. Fixed a major bug that caused incorrect computation of the amount of memory
795     required for a compiled pattern when options that changed within the
796     pattern affected the logic of the preliminary scan that determines the
797     length. The relevant options are -x, and -i in UTF-8 mode. The result was
798     that the computed length was too small. The symptoms of this bug were
799     either the PCRE error "internal error: code overflow" from pcre_compile(),
800     or a glibc crash with a message such as "pcretest: free(): invalid next
801     size (fast)". Examples of patterns that provoked this bug (shown in
802     pcretest format) are:
804     /(?-x: )/x
805     /(?x)(?-x: \s*#\s*)/
806     /((?i)[\x{c0}])/8
807     /(?i:[\x{c0}])/8
809     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
810     is now done differently.
812     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
813     wrapper classes; (b) implement a new function in the C++ scanner that is
814     more efficient than the old way of doing things because it avoids levels of
815     recursion in the regex matching; (c) add a paragraph to the documentation
816     for the FullMatch() function.
818     6. The escape sequence \n was being treated as whatever was defined as
819     "newline". Not only was this contrary to the documentation, which states
820     that \n is character 10 (hex 0A), but it also went horribly wrong when
821     "newline" was defined as CRLF. This has been fixed.
823     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
824     was being set to -1 for the "end of line" case (supposedly a value that no
825     character can have). Though this value is never used (the check for end of
826     line is "zero bytes in current character"), it caused compiler complaints.
827     I've changed it to 0xffffffff.
829     8. In pcre_version.c, the version string was being built by a sequence of
830     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
831     string (as it is for production releases) called a macro with an empty
832     argument. The C standard says the result of this is undefined. The gcc
833     compiler treats it as an empty string (which was what was wanted) but it is
834     reported that Visual C gives an error. The source has been hacked around to
835     avoid this problem.
837     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
838     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
839     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
840     of them did).
842     10. Originally, pcretest opened its input and output without "b"; then I was
843     told that "b" was needed in some environments, so it was added for release
844     5.0 to both the input and output. (It makes no difference on Unix-like
845     systems.) Later I was told that it is wrong for the input on Windows. I've
846     now abstracted the modes into two macros, to make it easier to fiddle with
847     them, and removed "b" from the input mode under Windows.
849     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
851     12. Added -help and --help to pcretest as an official way of being reminded
852     of the options.
854     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
855     and pcrecpp.cc because they annoy compilers at high warning levels.
857     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
859     15. Fixed an occurrence of == in configure.ac that should have been = (shell
860     scripts are not C programs :-) and which was not noticed because it works
861     on Linux.
863     16. pcretest is supposed to handle any length of pattern and data line (as one
864     line or as a continued sequence of lines) by extending its input buffer if
865     necessary. This feature was broken for very long pattern lines, leading to
866     a string of junk being passed to pcre_compile() if the pattern was longer
867     than about 50K.
869     17. I have done a major re-factoring of the way pcre_compile() computes the
870     amount of memory needed for a compiled pattern. Previously, there was code
871     that made a preliminary scan of the pattern in order to do this. That was
872     OK when PCRE was new, but as the facilities have expanded, it has become
873     harder and harder to keep it in step with the real compile phase, and there
874     have been a number of bugs (see for example, 4 above). I have now found a
875     cunning way of running the real compile function in a "fake" mode that
876     enables it to compute how much memory it would need, while actually only
877     ever using a few hundred bytes of working memory and without too many
878     tests of the mode. This should make future maintenance and development
879     easier. A side effect of this work is that the limit of 200 on the nesting
880     depth of parentheses has been removed (though this was never a serious
881     limitation, I suspect). However, there is a downside: pcre_compile() now
882     runs more slowly than before (30% or more, depending on the pattern). I
883     hope this isn't a big issue. There is no effect on runtime performance.
885     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
886     newline (only possible for the last line of a file) and it was a
887     pattern that set a locale (followed by /Lsomething), pcretest crashed.
889     19. Added additional timing features to pcretest. (1) The -tm option now times
890     matching only, not compiling. (2) Both -t and -tm can be followed, as a
891     separate command line item, by a number that specifies the number of
892     repeats to use when timing. The default is 50000; this gives better
893     precision, but takes uncomfortably long for very large patterns.
895     20. Extended pcre_study() to be more clever in cases where a branch of a
896     subpattern has no definite first character. For example, (a*|b*)[cd] would
897     previously give no result from pcre_study(). Now it recognizes that the
898     first character must be a, b, c, or d.
900     21. There was an incorrect error "recursive call could loop indefinitely" if
901     a subpattern (or the entire pattern) that was being tested for matching an
902     empty string contained only one non-empty item after a nested subpattern.
903     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
904     incorrectly, because the \d was being skipped in the check.
906     22. The pcretest program now has a new pattern option /B and a command line
907     option -b, which is equivalent to adding /B to every pattern. This causes
908     it to show the compiled bytecode, without the additional information that
909     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
910     is the same as /B/I).
912     23. A new optimization is now able automatically to treat some sequences such
913     as a*b as a*+b. More specifically, if something simple (such as a character
914     or a simple class like \d) has an unlimited quantifier, and is followed by
915     something that cannot possibly match the quantified thing, the quantifier
916     is automatically "possessified".
918     24. A recursive reference to a subpattern whose number was greater than 39
919     went wrong under certain circumstances in UTF-8 mode. This bug could also
920     have affected the operation of pcre_study().
922     25. Realized that a little bit of performance could be had by replacing
923     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
925     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
927     27. Possessive quantifiers such as a++ were previously implemented by turning
928     them into atomic groups such as ($>a+). Now they have their own opcodes,
929     which improves performance. This includes the automatically created ones
930     from 23 above.
932     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
933     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
934     the first matched character to be a colon. This applied both to named and
935     numbered groups.
937     29. The ucpinternal.h header file was missing its idempotency #ifdef.
939     30. I was sent a "project" file called libpcre.a.dev which I understand makes
940     building PCRE on Windows easier, so I have included it in the distribution.
942     31. There is now a check in pcretest against a ridiculously large number being
943     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
944     loop, the loop is abandoned.
946     32. Forward references to subpatterns in conditions such as (?(2)...) where
947     subpattern 2 is defined later cause pcre_compile() to search forwards in
948     the pattern for the relevant set of parentheses. This search went wrong
949     when there were unescaped parentheses in a character class, parentheses
950     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
952     33. "Subroutine" calls and backreferences were previously restricted to
953     referencing subpatterns earlier in the regex. This restriction has now
954     been removed.
956     34. Added a number of extra features that are going to be in Perl 5.10. On the
957     whole, these are just syntactic alternatives for features that PCRE had
958     previously implemented using the Python syntax or my own invention. The
959     other formats are all retained for compatibility.
961     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
962     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
963     also .NET compatible.
965     (b) A recursion or subroutine call to a named group can now be defined as
966     (?&name) as well as (?P>name).
968     (c) A backreference to a named group can now be defined as \k<name> or
969     \k'name' as well as (?P=name). The new forms, as well as being in Perl
970     5.10, are also .NET compatible.
972     (d) A conditional reference to a named group can now use the syntax
973     (?(<name>) or (?('name') as well as (?(name).
975     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
976     groups (named and numbered) that are never evaluated inline, but can be
977     called as "subroutines" from elsewhere. In effect, the DEFINE condition
978     is always false. There may be only one alternative in such a group.
980     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
981     as the simple (?(R). The condition is true only if the most recent
982     recursion is that of the given number or name. It does not search out
983     through the entire recursion stack.
985     (g) The escape \gN or \g{N} has been added, where N is a positive or
986     negative number, specifying an absolute or relative reference.
988     35. Tidied to get rid of some further signed/unsigned compiler warnings and
989     some "unreachable code" warnings.
991     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
992     things, this adds five new scripts.
994     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
995     There were also incompatibilities regarding the handling of \Q..\E inside
996     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
997     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
999     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1000     matches an empty string, and forcibly breaks the loop. There were bugs in
1001     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1002     against aaaa the result was just "a" rather than "aaaa", for example. Two
1003     separate and independent bugs (that affected different cases) have been
1004     fixed.
1006     39. Refactored the code to abolish the use of different opcodes for small
1007     capturing bracket numbers. This is a tidy that I avoided doing when I
1008     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1009     The new approach is not only tidier, it makes it possible to reduce the
1010     memory needed to fix the previous bug (38).
1012     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1013     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1014     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1015     mode.
1017     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1018     report.
1020     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1021     copy construction and assignment in the C++ wrapper.
1023     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1024     couple of bugs that could have given wrong results in the "--newline=crlf"
1025     case.
1027     44. Added a number of casts and did some reorganization of signed/unsigned int
1028     variables following suggestions from Dair Grant. Also renamed the variable
1029     "this" as "item" because it is a C++ keyword.
1031     45. Arranged for dftables to add
1033     #include "pcre_internal.h"
1035     to pcre_chartables.c because without it, gcc 4.x may remove the array
1036     definition from the final binary if PCRE is built into a static library and
1037     dead code stripping is activated.
1039     46. For an unanchored pattern, if a match attempt fails at the start of a
1040     newline sequence, and the newline setting is CRLF or ANY, and the next two
1041     characters are CRLF, advance by two characters instead of one.
1044 nigel 91 Version 6.7 04-Jul-06
1045     ---------------------
1047     1. In order to handle tests when input lines are enormously long, pcretest has
1048     been re-factored so that it automatically extends its buffers when
1049     necessary. The code is crude, but this _is_ just a test program. The
1050     default size has been increased from 32K to 50K.
1052     2. The code in pcre_study() was using the value of the re argument before
1053     testing it for NULL. (Of course, in any sensible call of the function, it
1054     won't be NULL.)
1056     3. The memmove() emulation function in pcre_internal.h, which is used on
1057     systems that lack both memmove() and bcopy() - that is, hardly ever -
1058     was missing a "static" storage class specifier.
1060     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1061     containing an extended class (one that cannot be represented by a bitmap
1062     because it contains high-valued characters or Unicode property items, e.g.
1063     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1064     pattern, but PCRE should not loop if you do not (it no longer does).
1065     [Detail: two cases were found: (a) a repeated subpattern containing an
1066     extended class; (b) a recursive reference to a subpattern that followed a
1067     previous extended class. It wasn't skipping over the extended class
1068     correctly when UTF-8 mode was not set.]
1070     5. A negated single-character class was not being recognized as fixed-length
1071     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1072     compile error "lookbehind assertion is not fixed length".
1074     6. The RunPerlTest auxiliary script was showing an unexpected difference
1075     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1076     write a Perl script that can interpret lines of an input file either as
1077     byte characters or as UTF-8, which is what "perltest" was being required to
1078     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1079     can't do is switch easily at run time between having the "use utf8;" pragma
1080     or not. In the end, I fudged it by using the RunPerlTest script to insert
1081     "use utf8;" explicitly for the UTF-8 tests.
1083     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1084     the end of the subject string, contrary to the documentation and to what
1085     Perl does. This was true of both matching functions. Now it matches only at
1086     the start of the subject and immediately after *internal* newlines.
1088     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1089     a pointer to an int instead of a pointer to an unsigned long int. This
1090     caused problems on 64-bit systems.
1092     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1093     instance of the 'standard' template library not being so standard".
1095     10. There was no check on the number of named subpatterns nor the maximum
1096     length of a subpattern name. The product of these values is used to compute
1097     the size of the memory block for a compiled pattern. By supplying a very
1098     long subpattern name and a large number of named subpatterns, the size
1099     computation could be caused to overflow. This is now prevented by limiting
1100     the length of names to 32 characters, and the number of named subpatterns
1101     to 10,000.
1103     11. Subpatterns that are repeated with specific counts have to be replicated in
1104     the compiled pattern. The size of memory for this was computed from the
1105     length of the subpattern and the repeat count. The latter is limited to
1106     65535, but there was no limit on the former, meaning that integer overflow
1107     could in principle occur. The compiled length of a repeated subpattern is
1108     now limited to 30,000 bytes in order to prevent this.
1110     12. Added the optional facility to have named substrings with the same name.
1112     13. Added the ability to use a named substring as a condition, using the
1113     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1114     are numbers (not recommended). Forward references are permitted.
1116     14. Added forward references in named backreferences (if you see what I mean).
1118     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1119     pattern could run off the end of the subject. For example, the pattern
1120     "(?s)(.{1,5})"8 did this with the subject "ab".
1122     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1123     PCRE_CASELESS was set when matching characters that were quantified with ?
1124     or *.
1126     17. A character class other than a single negated character that had a minimum
1127     but no maximum quantifier - for example [ab]{6,} - was not handled
1128     correctly by pce_dfa_exec(). It would match only one character.
1130     18. A valid (though odd) pattern that looked like a POSIX character
1131     class but used an invalid character after [ (for example [[,abc,]]) caused
1132     pcre_compile() to give the error "Failed: internal error: code overflow" or
1133     in some cases to crash with a glibc free() error. This could even happen if
1134     the pattern terminated after [[ but there just happened to be a sequence of
1135     letters, a binary zero, and a closing ] in the memory that followed.
1137     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1138     over the years. Originally (before any Unicode support), just the bottom 8
1139     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1140     output from "man perlunicode" includes this:
1142     The regular expression compiler produces polymorphic opcodes. That
1143     is, the pattern adapts to the data and automatically switches to
1144     the Unicode character scheme when presented with Unicode data--or
1145     instead uses a traditional byte scheme when presented with byte
1146     data.
1148     Sadly, a wide octal escape does not cause a switch, and in a string with
1149     no other multibyte characters, these octal escapes are treated as before.
1150     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1151     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1152     Unicode string.
1154     I have not perpetrated such confusion in PCRE. Up till now, it took just
1155     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1156     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1157     translate to the appropriate multibyte character.
1159     29. Applied some refactoring to reduce the number of warnings from Microsoft
1160     and Borland compilers. This has included removing the fudge introduced
1161     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1162     a warning about an unused variable.
1164     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1165     characters since release 4.0, because Perl (from release 5.004) does not.
1166     [Or at least, is documented not to: some releases seem to be in conflict
1167     with the documentation.] However, when a pattern was studied with
1168     pcre_study() and all its branches started with \s, PCRE still included VT
1169     as a possible starting character. Of course, this did no harm; it just
1170     caused an unnecessary match attempt.
1172     22. Removed a now-redundant internal flag bit that recorded the fact that case
1173     dependency changed within the pattern. This was once needed for "required
1174     byte" processing, but is no longer used. This recovers a now-scarce options
1175     bit. Also moved the least significant internal flag bit to the most-
1176     significant bit of the word, which was not previously used (hangover from
1177     the days when it was an int rather than a uint) to free up another bit for
1178     the future.
1180     23. Added support for CRLF line endings as well as CR and LF. As well as the
1181     default being selectable at build time, it can now be changed at runtime
1182     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1183     specify that it is scanning data with non-default line endings.
1185     24. Changed the definition of CXXLINK to make it agree with the definition of
1186     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1188     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1189     recursions. This makes a big different to stack usage for some patterns.
1191     26. If a subpattern containing a named recursion or subroutine reference such
1192     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1193     the space required for the compiled pattern went wrong and gave too small a
1194     value. Depending on the environment, this could lead to "Failed: internal
1195     error: code overflow at offset 49" or "glibc detected double free or
1196     corruption" errors.
1198     27. Applied patches from Google (a) to support the new newline modes and (b) to
1199     advance over multibyte UTF-8 characters in GlobalReplace.
1201     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1202     difference for some implementation of PCRE in some Windows version.
1204     29. Added some extra testing facilities to pcretest:
1206     \q<number> in a data line sets the "match limit" value
1207     \Q<number> in a data line sets the "match recursion limt" value
1208     -S <number> sets the stack size, where <number> is in megabytes
1210     The -S option isn't available for Windows.
1213 nigel 89 Version 6.6 06-Feb-06
1214     ---------------------
1216     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1217     in pcreposix.h. I have copied the definition from pcre.h.
1219     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1220     because pcre.h is no longer a built file.
1222     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1223     not normally included in the compiled code.
1226 nigel 87 Version 6.5 01-Feb-06
1227     ---------------------
1229     1. When using the partial match feature with pcre_dfa_exec(), it was not
1230     anchoring the second and subsequent partial matches at the new starting
1231     point. This could lead to incorrect results. For example, with the pattern
1232     /1234/, partially matching against "123" and then "a4" gave a match.
1234     2. Changes to pcregrep:
1236     (a) All non-match returns from pcre_exec() were being treated as failures
1237     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1238     error message is output. Some extra information is given for the
1240     probably the only errors that are likely to be caused by users (by
1241     specifying a regex that has nested indefinite repeats, for instance).
1242     If there are more than 20 of these errors, pcregrep is abandoned.
1244     (b) A binary zero was treated as data while matching, but terminated the
1245     output line if it was written out. This has been fixed: binary zeroes
1246     are now no different to any other data bytes.
1248     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1249     used to set a locale for matching. The --locale=xxxx long option has
1250     been added (no short equivalent) to specify a locale explicitly on the
1251     pcregrep command, overriding the environment variables.
1253     (d) When -B was used with -n, some line numbers in the output were one less
1254     than they should have been.
1256     (e) Added the -o (--only-matching) option.
1258     (f) If -A or -C was used with -c (count only), some lines of context were
1259     accidentally printed for the final match.
1261     (g) Added the -H (--with-filename) option.
1263     (h) The combination of options -rh failed to suppress file names for files
1264     that were found from directory arguments.
1266     (i) Added the -D (--devices) and -d (--directories) options.
1268     (j) Added the -F (--fixed-strings) option.
1270     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1272     (l) Added the --colo(u)r option.
1274     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1275     is not present by default.
1277     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1278     items such as (?R) or (?1), when the recursion could match a number of
1279     alternatives. If it matched one of the alternatives, but subsequently,
1280     outside the recursion, there was a failure, the code tried to back up into
1281     the recursion. However, because of the way PCRE is implemented, this is not
1282     possible, and the result was an incorrect result from the match.
1284     In order to prevent this happening, the specification of recursion has
1285     been changed so that all such subpatterns are automatically treated as
1286     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1288     4. I had overlooked the fact that, in some locales, there are characters for
1289     which isalpha() is true but neither isupper() nor islower() are true. In
1290     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1291     and ordfeminine) are like this. This affected the treatment of \w and \W
1292     when they appeared in character classes, but not when they appeared outside
1293     a character class. The bit map for "word" characters is now created
1294     separately from the results of isalnum() instead of just taking it from the
1295     upper, lower, and digit maps. (Plus the underscore character, of course.)
1297     5. The above bug also affected the handling of POSIX character classes such as
1298     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1299     permanent tables. Instead, the bit maps for such a class were previously
1300     created as the appropriate unions of the upper, lower, and digit bitmaps.
1301     Now they are created by subtraction from the [[:word:]] class, which has
1302     its own bitmap.
1304     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1305     It is created by subtracting the vertical space characters (\x09, \x0a,
1306     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1307     subtraction was done in the overall bitmap for a character class, meaning
1308     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1309     be recognized. This bug has been fixed.
1311     7. Patches from the folks at Google:
1313     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1314     real life, but is still worth protecting against".
1316     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1317     regular expressions".
1319     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1320     have it.
1322     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1323     "configure" and the latter not, in order to fix a problem somebody had
1324     with compiling the Arg class on HP-UX.
1326     (e) Improve the error-handling of the C++ wrapper a little bit.
1328     (f) New tests for checking recursion limiting.
1330     8. The pcre_memmove() function, which is used only if the environment does not
1331     have a standard memmove() function (and is therefore rarely compiled),
1332     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1333     returning a result (though PCRE never actually uses the result).
1335     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1336     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1337     returned instead of calling malloc() with an overflowing number that would
1338     most likely cause subsequent chaos.
1340     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1342     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1343     with this option is matched, the nmatch and pmatch options of regexec() are
1344     ignored.
1346     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1347     provided in case anyone wants to the the POSIX interface with UTF-8
1348     strings.
1350     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1351     C++ linking (needed for some HP-UX environments).
1353     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1354     (unused parameter) and in the pcre_printint() function (omitted "default"
1355     switch label when the default is to do nothing).
1357     15. Added some code to make it possible, when PCRE is compiled as a C++
1358     library, to replace subject pointers for pcre_exec() with a smart pointer
1359     class, thus making it possible to process discontinuous strings.
1361     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1362     much the same function. They were added by different people who were trying
1363     to make PCRE easy to compile on non-Unix systems. It has been suggested
1364     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1365     for compiling on Windows systems. I have therefore replaced it with
1366     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1367     defaults to "extern" for C or "extern C" for C++, which works fine on
1368     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1369     SCOPE with something explicit in config.h. In addition:
1371     (a) pcreposix.h still had just "extern" instead of either of these macros;
1372     I have replaced it with PCRE_DATA_SCOPE.
1374     (b) Functions such as _pcre_xclass(), which are internal to the library,
1375     but external in the C sense, all had PCRE_EXPORT in their definitions.
1376     This is apparently wrong for the Windows case, so I have removed it.
1377     (It makes no difference on Unix-like systems.)
1379     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1380     of recursive calls to match(). This is different to MATCH_LIMIT because
1381     that limits the total number of calls to match(), not all of which increase
1382     the depth of recursion. Limiting the recursion depth limits the amount of
1383     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1384     when PCRE is compiled, and changed at run time. A patch from Google adds
1385     this functionality to the C++ interface.
1387     18. Changes to the handling of Unicode character properties:
1389     (a) Updated the table to Unicode 4.1.0.
1391     (b) Recognize characters that are not in the table as "Cn" (undefined).
1393     (c) I revised the way the table is implemented to a much improved format
1394     which includes recognition of ranges. It now supports the ranges that
1395     are defined in UnicodeData.txt, and it also amalgamates other
1396     characters into ranges. This has reduced the number of entries in the
1397     table from around 16,000 to around 3,000, thus reducing its size
1398     considerably. I realized I did not need to use a tree structure after
1399     all - a binary chop search is just as efficient. Having reduced the
1400     number of entries, I extended their size from 6 bytes to 8 bytes to
1401     allow for more data.
1403     (d) Added support for Unicode script names via properties such as \p{Han}.
1405     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1406     matching that character.
1408     20. When matching a repeated Unicode property with a minimum greater than zero,
1409     (for example \pL{2,}), PCRE could look past the end of the subject if it
1410     reached it while seeking the minimum number of characters. This could
1411     happen only if some of the characters were more than one byte long, because
1412     there is a check for at least the minimum number of bytes.
1414     21. Refactored the implementation of \p and \P so as to be more general, to
1415     allow for more different types of property in future. This has changed the
1416     compiled form incompatibly. Anybody with saved compiled patterns that use
1417     \p or \P will have to recompile them.
1419     22. Added "Any" and "L&" to the supported property types.
1421     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1422     but give a compile time error if the value is greater than 0xff.
1424     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1425     accidentally not being installed or uninstalled.
1427     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1428     made were to insert the current release number. This seemed silly, because
1429     it made things harder for people building PCRE on systems that don't run
1430     "configure". I have turned pcre.h into a distributed file, no longer built
1431     by "configure", with the version identification directly included. There is
1432     no longer a pcre.h.in file.
1434     However, this change necessitated a change to the pcre-config script as
1435     well. It is built from pcre-config.in, and one of the substitutions was the
1436     release number. I have updated configure.ac so that ./configure now finds
1437     the release number by grepping pcre.h.
1439     26. Added the ability to run the tests under valgrind.
1442 nigel 85 Version 6.4 05-Sep-05
1443     ---------------------
1445     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1446     "--" to be printed when multiple files were scanned, even when none of the
1447     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1448     consider it to be a bug, and have restored the previous behaviour.
1450     2. A couple of code tidies to get rid of compiler warnings.
1452     3. The pcretest program used to cheat by referring to symbols in the library
1453     whose names begin with _pcre_. These are internal symbols that are not
1454     really supposed to be visible externally, and in some environments it is
1455     possible to suppress them. The cheating is now confined to including
1456     certain files from the library's source, which is a bit cleaner.
1458     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1459     file's purpose clearer.
1461     5. Reorganized pcre_ucp_findchar().
1464 nigel 83 Version 6.3 15-Aug-05
1465     ---------------------
1467     1. The file libpcre.pc.in did not have general read permission in the tarball.
1469     2. There were some problems when building without C++ support:
1471     (a) If C++ support was not built, "make install" and "make test" still
1472     tried to test it.
1474     (b) There were problems when the value of CXX was explicitly set. Some
1475     changes have been made to try to fix these, and ...
1477     (c) --disable-cpp can now be used to explicitly disable C++ support.
1479     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1480     backslash in a target when C++ was disabled. This confuses some
1481     versions of "make", apparently. Using an intermediate variable solves
1482     this. (Same for CPP_LOBJ.)
1484     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1485     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1486     necessary on certain architectures.
1488     4. Added a setting of -export-symbols-regex to the link command to remove
1489     those symbols that are exported in the C sense, but actually are local
1490     within the library, and not documented. Their names all begin with
1491     "_pcre_". This is not a perfect job, because (a) we have to except some
1492     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1493     available (and never for static libraries). I have made a note to try to
1494     find a way round (a) in the future.
1497 nigel 81 Version 6.2 01-Aug-05
1498     ---------------------
1500     1. There was no test for integer overflow of quantifier values. A construction
1501     such as {1111111111111111} would give undefined results. What is worse, if
1502     a minimum quantifier for a parenthesized subpattern overflowed and became
1503     negative, the calculation of the memory size went wrong. This could have
1504     led to memory overwriting.
1506     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1508     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1509     operating environments where this matters.
1511     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1512     PCRE options from within the C++ wrapper.
1514     5. Named capturing subpatterns were not being correctly counted when a pattern
1515     was compiled. This caused two problems: (a) If there were more than 100
1516     such subpatterns, the calculation of the memory needed for the whole
1517     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1518     back references of the form \12, where the number was greater than 9, were
1519     not recognized as back references, even though there were sufficient
1520     previous subpatterns.
1522     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1523     versions of gcc, e.g. 2.95.4.
1526 nigel 79 Version 6.1 21-Jun-05
1527     ---------------------
1529     1. There was one reference to the variable "posix" in pcretest.c that was not
1530     surrounded by "#if !defined NOPOSIX".
1532     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1533     the cross-check on the old pcre_info() function, for the benefit of the
1534     cut-down version of PCRE that is currently imported into Exim.
1536     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1537     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1538     patterns that start (?i) but I don't think that matters. The use of (?i) is
1539     just an example; this all applies to the other options as well.
1541     4. Since libtool seems to echo the compile commands it is issuing, the output
1542     from "make" can be reduced a bit by putting "@" in front of each libtool
1543     compile command.
1545     5. Patch from the folks at Google for configure.in to be a bit more thorough
1546     in checking for a suitable C++ installation before trying to compile the
1547     C++ stuff. This should fix a reported problem when a compiler was present,
1548     but no suitable headers.
1550     6. The man pages all had just "PCRE" as their title. I have changed them to
1551     be the relevant file name. I have also arranged that these names are
1552     retained in the file doc/pcre.txt, which is a concatenation in text format
1553     of all the man pages except the little individual ones for each function.
1555     7. The NON-UNIX-USE file had not been updated for the different set of source
1556     files that come with release 6. I also added a few comments about the C++
1557     wrapper.
1560 nigel 77 Version 6.0 07-Jun-05
1561     ---------------------
1563     1. Some minor internal re-organization to help with my DFA experiments.
1565     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1566     didn't matter for the library itself when fully configured, but did matter
1567     when compiling without UCP support, or within Exim, where the ucp files are
1568     not imported.
1570     3. Refactoring of the library code to split up the various functions into
1571     different source modules. The addition of the new DFA matching code (see
1572     below) to a single monolithic source would have made it really too
1573     unwieldy, quite apart from causing all the code to be include in a
1574     statically linked application, when only some functions are used. This is
1575     relevant even without the DFA addition now that patterns can be compiled in
1576     one application and matched in another.
1578     The downside of splitting up is that there have to be some external
1579     functions and data tables that are used internally in different modules of
1580     the library but which are not part of the API. These have all had their
1581     names changed to start with "_pcre_" so that they are unlikely to clash
1582     with other external names.
1584     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1585     a different (DFA) algorithm. Although it is slower than the original
1586     function, it does have some advantages for certain types of matching
1587     problem.
1589     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1590     including restarting after a partial match.
1592     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1593     defined when compiling for Windows was sent to me. I have put it into the
1594     code, though I have no means of testing or verifying it.
1596     7. Added the pcre_refcount() auxiliary function.
1598     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1599     match before or at the first newline in the subject string. In pcretest,
1600     the /f option on a pattern can be used to set this.
1602     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1603     would behave wrongly. This has been present in PCRE since release 4.0.
1605     10. A number of changes to the pcregrep command:
1607     (a) Refactored how -x works; insert ^(...)$ instead of setting
1608     PCRE_ANCHORED and checking the length, in preparation for adding
1609     something similar for -w.
1611     (b) Added the -w (match as a word) option.
1613     (c) Refactored the way lines are read and buffered so as to have more
1614     than one at a time available.
1616     (d) Implemented a pcregrep test script.
1618     (e) Added the -M (multiline match) option. This allows patterns to match
1619     over several lines of the subject. The buffering ensures that at least
1620     8K, or the rest of the document (whichever is the shorter) is available
1621     for matching (and similarly the previous 8K for lookbehind assertions).
1623     (f) Changed the --help output so that it now says
1625     -w, --word-regex(p)
1627     instead of two lines, one with "regex" and the other with "regexp"
1628     because that confused at least one person since the short forms are the
1629     same. (This required a bit of code, as the output is generated
1630     automatically from a table. It wasn't just a text change.)
1632     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1633     option but starts with a hyphen. Could be a pattern or a path name
1634     starting with a hyphen, for instance.
1636     (h) "-" can be given as a file name to represent stdin.
1638     (i) When file names are being printed, "(standard input)" is used for
1639     the standard input, for compatibility with GNU grep. Previously
1640     "<stdin>" was used.
1642     (j) The option --label=xxx can be used to supply a name to be used for
1643     stdin when file names are being printed. There is no short form.
1645     (k) Re-factored the options decoding logic because we are going to add
1646     two more options that take data. Such options can now be given in four
1647     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1649     (l) Added the -A, -B, and -C options for requesting that lines of context
1650     around matches be printed.
1652     (m) Added the -L option to print the names of files that do not contain
1653     any matching lines, that is, the complement of -l.
1655     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1656     continue to scan other files.
1658     (o) The -s option was incorrectly implemented. For compatibility with other
1659     greps, it now suppresses the error message for a non-existent or non-
1660     accessible file (but not the return code). There is a new option called
1661     -q that suppresses the output of matching lines, which was what -s was
1662     previously doing.
1664     (p) Added --include and --exclude options to specify files for inclusion
1665     and exclusion when recursing.
1667     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1668     Hopefully, it now does.
1670     12. Missing cast in pcre_study().
1672     13. Added an "uninstall" target to the makefile.
1674     14. Replaced "extern" in the function prototypes in Makefile.in with
1675     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1676     world, but is set differently for Windows.
1678     15. Added a second compiling function called pcre_compile2(). The only
1679     difference is that it has an extra argument, which is a pointer to an
1680     integer error code. When there is a compile-time failure, this is set
1681     non-zero, in addition to the error test pointer being set to point to an
1682     error message. The new argument may be NULL if no error number is required
1683     (but then you may as well call pcre_compile(), which is now just a
1684     wrapper). This facility is provided because some applications need a
1685     numeric error indication, but it has also enabled me to tidy up the way
1686     compile-time errors are handled in the POSIX wrapper.
1688     16. Added VPATH=.libs to the makefile; this should help when building with one
1689     prefix path and installing with another. (Or so I'm told by someone who
1690     knows more about this stuff than I do.)
1692     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1693     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1694     match everything, including newlines. This is not POSIX-compatible, but
1695     somebody wanted the feature. From pcretest it can be activated by using
1696     both the P and the s flags.
1698     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1700     19. libpcre.pc was being incorrectly installed as executable.
1702     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1703     it now also looks for '\r' so that it will work unmodified on Windows.
1705     21. Added Google's contributed C++ wrapper to the distribution.
1707     22. Added some untidy missing memory free() calls in pcretest, to keep
1708     Electric Fence happy when testing.
1712 nigel 75 Version 5.0 13-Sep-04
1713     ---------------------
1715     1. Internal change: literal characters are no longer packed up into items
1716     containing multiple characters in a single byte-string. Each character
1717     is now matched using a separate opcode. However, there may be more than one
1718     byte in the character in UTF-8 mode.
1720     2. The pcre_callout_block structure has two new fields: pattern_position and
1721     next_item_length. These contain the offset in the pattern to the next match
1722     item, and its length, respectively.
1724     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1725     insertion of callouts before each pattern item. Added the /C option to
1726     pcretest to make use of this.
1728     4. On the advice of a Windows user, the lines
1730     #if defined(_WIN32) || defined(WIN32)
1731     _setmode( _fileno( stdout ), 0x8000 );
1732     #endif /* defined(_WIN32) || defined(WIN32) */
1734     have been added to the source of pcretest. This apparently does useful
1735     magic in relation to line terminators.
1737     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1738     for the benefit of those environments where the "b" makes a difference.
1740     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1741     to know about it. I have put a hack into configure.in that adds in code
1742     to set GCC=yes if CC=icc. This seems to end up at a point in the
1743     generated configure script that is early enough to affect the setting of
1744     compiler options, which is what is needed, but I have no means of testing
1745     whether it really works. (The user who reported this had patched the
1746     generated configure script, which of course I cannot do.)
1748     LATER: After change 22 below (new libtool files), the configure script
1749     seems to know about icc (and also ecc). Therefore, I have commented out
1750     this hack in configure.in.
1752     7. Added support for pkg-config (2 patches were sent in).
1754     8. Negated POSIX character classes that used a combination of internal tables
1755     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1756     [[:^ascii]]. Typically, they would match almost any characters. The other
1757     POSIX classes were not broken in this way.
1759     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1760     to find the match, as PCRE was deluded into thinking that the match had to
1761     start at the start point or following a newline. The same bug applied to
1762     patterns with negative forward assertions or any backward assertions
1763     preceding ".*" at the start, unless the pattern required a fixed first
1764     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1766     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1767     starting at the last subject character, bytes beyond the end of the subject
1768     string were read.
1770     11. Renamed the variable "class" as "classbits" to make life easier for C++
1771     users. (Previously there was a macro definition, but it apparently wasn't
1772     enough.)
1774     12. Added the new field "tables" to the extra data so that tables can be passed
1775     in at exec time, or the internal tables can be re-selected. This allows
1776     a compiled regex to be saved and re-used at a later time by a different
1777     program that might have everything at different addresses.
1779     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1780     -R library as well as a -L library.
1782     14. The debugging options of pcretest (-d on the command line or D on a
1783     pattern) showed incorrect output for anything following an extended class
1784     that contained multibyte characters and which was followed by a quantifier.
1786     15. Added optional support for general category Unicode character properties
1787     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1788     support. It adds about 90K to the size of the library. The meanings of the
1789     inbuilt class escapes such as \d and \s have NOT been changed.
1791     16. Updated pcredemo.c to include calls to free() to release the memory for the
1792     compiled pattern.
1794     17. The generated file chartables.c was being created in the source directory
1795     instead of in the building directory. This caused the build to fail if the
1796     source directory was different from the building directory, and was
1797     read-only.
1799     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1800     file. No doubt somebody will tell me if they don't make sense... Also added
1801     Dan Mooney's comments about building on OpenVMS.
1803     19. Added support for partial matching via the PCRE_PARTIAL option for
1804     pcre_exec() and the \P data escape in pcretest.
1806     20. Extended pcretest with 3 new pattern features:
1808     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1809     write the compiled pattern to the file whose name is "rest-of-line".
1810     This is a straight binary dump of the data, with the saved pointer to
1811     the character tables forced to be NULL. The study data, if any, is
1812     written too. After writing, pcretest reads a new pattern.
1814     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1815     compiled pattern from the given file. There must not be any
1816     occurrences of "<" in the file name (pretty unlikely); if there are,
1817     pcretest will instead treat the initial "<" as a pattern delimiter.
1818     After reading in the pattern, pcretest goes on to read data lines as
1819     usual.
1821     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1822     and 16-bit fields in a compiled pattern, to simulate a pattern that
1823     was compiled on a host of opposite endianness.
1825     21. The pcre-exec() function can now cope with patterns that were compiled on
1826     hosts of opposite endianness, with this restriction:
1828     As for any compiled expression that is saved and used later, the tables
1829     pointer field cannot be preserved; the extra_data field in the arguments
1830     to pcre_exec() should be used to pass in a tables address if a value
1831     other than the default internal tables were used at compile time.
1833     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1834     now diagnosed as an error. Previously, most of the time, a negative number
1835     would have been treated as zero, but if in addition "ovector" was passed as
1836     NULL, a crash could occur.
1838     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1839     new versions from the libtool 1.5 distribution (the last one is a copy of
1840     a file called libtool.m4). This seems to have fixed the need to patch
1841     "configure" to support Darwin 1.3 (which I used to do). However, I still
1842     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1843     workstation).
1845     24. Changed the PCRE licence to be the more standard "BSD" licence.
1848 nigel 73 Version 4.5 01-Dec-03
1849     ---------------------
1851     1. There has been some re-arrangement of the code for the match() function so
1852     that it can be compiled in a version that does not call itself recursively.
1853     Instead, it keeps those local variables that need separate instances for
1854     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1855     needs to "recurse". Keeping track of where control must go is done by means
1856     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1857     hide most of the details from the main code, and operates only if
1858     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1859     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1860     operating.
1862     To make it easier for callers to provide specially tailored get/free
1863     functions for this usage, two new functions, pcre_stack_malloc, and
1864     pcre_stack_free, are used. They are always called in strict stacking order,
1865     and the size of block requested is always the same.
1867     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1868     PCRE has been compiled to use the stack or the heap for recursion. The
1869     -C option of pcretest uses this to show which version is compiled.
1871     A new data escape \S, is added to pcretest; it causes the amounts of store
1872     obtained and freed by both kinds of malloc/free at match time to be added
1873     to the output.
1875     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1876     what's available on my current Linux desktop machine.
1878     3. When matching a UTF-8 string, the test for a valid string at the start has
1879     been extended. If start_offset is not zero, PCRE now checks that it points
1880     to a byte that is the start of a UTF-8 character. If not, it returns
1881     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1882     this is necessary because there may be backward assertions in the pattern.
1883     When matching the same subject several times, it may save resources to use
1884     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1886     4. The code for checking the validity of UTF-8 strings has been tightened so
1887     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1888     containing "overlong sequences".
1890     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1891     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1892     should have been "&", but it just so happened that all the cases this let
1893     through by mistake were picked up later in the function.
1895     6. I had used a variable called "isblank" - this is a C99 function, causing
1896     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1898     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1899     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1900     so the version is shown; (c) stop "make test" echoing "./RunTest".
1902     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1904     9. The prototype for memmove() for systems that don't have it was using
1905     size_t, but the inclusion of the header that defines size_t was later. I've
1906     moved the #includes for the C headers earlier to avoid this.
1908     10. Added some adjustments to the code to make it easier to compiler on certain
1909     special systems:
1911     (a) Some "const" qualifiers were missing.
1912     (b) Added the macro EXPORT before all exported functions; by default this
1913     is defined to be empty.
1914     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1915     that it reads its output file name as an argument instead of writing
1916     to the standard output and assuming this can be redirected.
1918     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1919     class containing characters with values greater than 255, PCRE compilation
1920     went into a loop.
1922     12. A recursive reference to a subpattern that was within another subpattern
1923     that had a minimum quantifier of zero caused PCRE to crash. For example,
1924     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1925     recursion. If the recursively-called subpattern itself had a zero repeat,
1926     that was OK.
1928     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1929     buffer into which it was copied (for escape processing) was still set at
1930     1024, so long lines caused crashes.
1932     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1933     "internal error: code overflow...". This applied to any character class
1934     that was followed by a possessive quantifier.
1936     15. Modified the Makefile to add libpcre.la as a prerequisite for
1937     libpcreposix.la because I was told this is needed for a parallel build to
1938     work.
1940     16. If a pattern that contained .* following optional items at the start was
1941     studied, the wrong optimizing data was generated, leading to matching
1942     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1943     matching string must start with a or b or c. The correct conclusion for
1944     this pattern is that a match can start with any character.
1947 nigel 71 Version 4.4 13-Aug-03
1948     ---------------------
1950     1. In UTF-8 mode, a character class containing characters with values between
1951     127 and 255 was not handled correctly if the compiled pattern was studied.
1952     In fixing this, I have also improved the studying algorithm for such
1953     classes (slightly).
1955     2. Three internal functions had redundant arguments passed to them. Removal
1956     might give a very teeny performance improvement.
1958     3. Documentation bug: the value of the capture_top field in a callout is *one
1959     more than* the number of the hightest numbered captured substring.
1961     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1962     in incorrectly linking with a previously installed version. They now link
1963     explicitly with libpcre.la.
1965     5. configure.in no longer needs to recognize Cygwin specially.
1967     6. A problem in pcre.in for Windows platforms is fixed.
1969     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1970     pcretest, it used to include the size of the study block as part of its
1971     output. Unfortunately, the structure contains a field that has a different
1972     size on different hardware architectures. This meant that the tests that
1973     showed this size failed. As the block is currently always of a fixed size,
1974     this information isn't actually particularly useful in pcretest output, so
1975     I have just removed it.
1977     8. Three pre-processor statements accidentally did not start in column 1.
1978     Sadly, there are *still* compilers around that complain, even though
1979     standard C has not required this for well over a decade. Sigh.
1981     9. In pcretest, the code for checking callouts passed small integers in the
1982     callout_data field, which is a void * field. However, some picky compilers
1983     complained about the casts involved for this on 64-bit systems. Now
1984     pcretest passes the address of the small integer instead, which should get
1985     rid of the warnings.
1987     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1988     both compile and run time, and gives an error if an invalid UTF-8 sequence
1989     is found. There is a option for disabling this check in cases where the
1990     string is known to be correct and/or the maximum performance is wanted.
1992     11. In response to a bug report, I changed one line in Makefile.in from
1994     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1995     to
1996     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1998     to look similar to other lines, but I have no way of telling whether this
1999     is the right thing to do, as I do not use Windows. No doubt I'll get told
2000     if it's wrong...
2003 nigel 69 Version 4.3 21-May-03
2004     ---------------------
2006     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2007     Makefile.
2009     2. Some refactoring to improve the quality of the code:
2011     (i) The utf8_table... variables are now declared "const".
2013     (ii) The code for \cx, which used the "case flipping" table to upper case
2014     lower case letters, now just substracts 32. This is ASCII-specific,
2015     but the whole concept of \cx is ASCII-specific, so it seems
2016     reasonable.
2018     (iii) PCRE was using its character types table to recognize decimal and
2019     hexadecimal digits in the pattern. This is silly, because it handles
2020     only 0-9, a-f, and A-F, but the character types table is locale-
2021     specific, which means strange things might happen. A private
2022     table is now used for this - though it costs 256 bytes, a table is
2023     much faster than multiple explicit tests. Of course, the standard
2024     character types table is still used for matching digits in subject
2025     strings against \d.
2027     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2028     ending in _t are). So I've renamed it as ESC_tee.
2030     3. The first argument for regexec() in the POSIX wrapper should have been
2031     defined as "const".
2033     4. Changed pcretest to use malloc() for its buffers so that they can be
2034     Electric Fenced for debugging.
2036     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2037     to read one or more bytes before the start of the subject string. Often this
2038     had no effect on PCRE's behaviour, but in some circumstances it could
2039     provoke a segmentation fault.
2041     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2042     to try to read one or more bytes before the start of the subject string.
2044     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2045     UTF-8 support could misbehave in various ways if the subject string
2046     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2047     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2048     back over UTF-8 characters.)
2051 nigel 67 Version 4.2 14-Apr-03
2052     ---------------------
2054     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2056     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2057     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2058     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2059     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2060     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2061     and BUILD_EXEEXT
2062     Note: automatic setting of the BUILD variables is not yet working
2063     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2064     compile-time but not at link-time
2065     [LINK]: use for linking executables only
2066     make different versions for Windows and non-Windows
2067     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2068     libraries
2069     [LINK_FOR_BUILD]: new variable
2070     [OBJEXT]: use throughout
2071     [EXEEXT]: use throughout
2072     <winshared>: new target
2073     <wininstall>: new target
2074     <dftables.o>: use native compiler
2075     <dftables>: use native linker
2076     <install>: handle Windows platform correctly
2077     <clean>: ditto
2078     <check>: ditto
2079     copy DLL to top builddir before testing
2081     As part of these changes, -no-undefined was removed again. This was reported
2082     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2083     in any case.
2085     3. Some tidies to get rid of compiler warnings:
2087     . In the match_data structure, match_limit was an unsigned long int, whereas
2088     match_call_count was an int. I've made them both unsigned long ints.
2090     . In pcretest the fact that a const uschar * doesn't automatically cast to
2091     a void * provoked a warning.
2093     . Turning on some more compiler warnings threw up some "shadow" variables
2094     and a few more missing casts.
2096     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2097     option, a class that contained a single character with a value between 128
2098     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2100     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2101     option, a class that contained several characters, but with at least one
2102     whose value was between 128 and 255 caused PCRE to crash.
2105 nigel 65 Version 4.1 12-Mar-03
2106     ---------------------
2107 nigel 63
2108 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2109     needed, and a string in dftables.c that was longer than standard compilers are
2110     required to support.
2112     2. Compiling with Sun's compiler found a few more places where the code could
2113     be tidied up in order to avoid warnings.
2115     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2116     first of these names is deprecated in the latest Autoconf in favour of the name
2117     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2118     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2119     analogy I have changed it to CFLAGS_FOR_BUILD.
2121     4. Added -no-undefined to the linking command in the Makefile, because this is
2122     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2123     linking step for the pcreposix library.
2125     5. PCRE was failing to diagnose the case of two named groups with the same
2126     name.
2128     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2129     literal character that is needed in the subject for a match, and scans along to
2130     ensure that it is present before embarking on the full matching process. This
2131     saves time in cases of nested unlimited repeats that are never going to match.
2132     Problem: the scan can take a lot of time if the subject is very long (e.g.
2133     megabytes), thus penalizing straightforward matches. It is now done only if the
2134     amount of subject to be scanned is less than 1000 bytes.
2136     7. A lesser problem with the same optimization is that it was recording the
2137     first character of an anchored pattern as "needed", thus provoking a search
2138     right along the subject, even when the first match of the pattern was going to
2139     fail. The "needed" character is now not set for anchored patterns, unless it
2140     follows something in the pattern that is of non-fixed length. Thus, it still
2141     fulfils its original purpose of finding quick non-matches in cases of nested
2142     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2145     Version 4.0 17-Feb-03
2146     ---------------------
2148 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2149     extended to the end of string, PCRE compiled incorrect data. This could lead to
2150     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2152     2. Moved to autoconf 2.53 and libtool 1.4.2.
2154     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2155     the special perltest8 script is no longer needed - all the tests can be run
2156     from a single perltest script.
2158     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2159     by \s. It has now been removed in PCRE. This means it isn't recognized as
2160     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2161     class [:space:] *does* include VT, thereby creating a mess.
2163     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2164     space and tab.
2166     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2167     its new features into the main test script, reducing the number of scripts.
2169     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2170     were backward compatible, and made the (?i) apply to the whole pattern, as if
2171     /i were given. Now it behaves more logically, and applies the option setting
2172     only to what follows. PCRE has been changed to follow suit. However, if it
2173     finds options settings right at the start of the pattern, it extracts them into
2174     the global options, as before. Thus, they show up in the info data.
2176     8. Added support for the \Q...\E escape sequence. Characters in between are
2177     treated as literals. This is slightly different from Perl in that $ and @ are
2178     also handled as literals inside the quotes. In Perl, they will cause variable
2179     interpolation. Note the following examples:
2181     Pattern PCRE matches Perl matches
2183     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2184     \Qabc\$xyz\E abc\$xyz abc\$xyz
2185     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2187     For compatibility with Perl, \Q...\E sequences are recognized inside character
2188     classes as well as outside them.
2190     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2191     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2192     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2193     signed/unsigned warnings.
2195     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2196     option for pcretest, so I've replaced it by a simple function that does just
2197     that job.
2199     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2200     "pcregrep -".
2202     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2203     Java package. This provides some syntactic sugar for simple cases of what my
2204     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2205     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2206     item, you can use this simplified notation. Note that only makes sense with
2207     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2208     greediness, whatever the setting of the PCRE_UNGREEDY option.
2210     13. A change of greediness default within a pattern was not taking effect at
2211     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2212     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2213     was abstracted outside.
2215     14. PCRE now supports the \G assertion. It is true when the current matching
2216     position is at the start point of the match. This differs from \A when the
2217     starting offset is non-zero. Used with the /g option of pcretest (or similar
2218     code), it works in the same way as it does for Perl's /g option. If all
2219     alternatives of a regex begin with \G, the expression is anchored to the start
2220     match position, and the "anchored" flag is set in the compiled expression.
2222     15. Some bugs concerning the handling of certain option changes within patterns
2223     have been fixed. These applied to options other than (?ims). For example,
2224     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2225     been the other way round. Some of this was related to change 7 above.
2227     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2228     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2229     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2230     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2232     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2233     mode. Unlike ".", it always matches newline, whatever the setting of
2234     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2235     assertions. Perl allows it, but it doesn't (in general) work because it can't
2236     calculate the length of the lookbehind. At least, that's the case for Perl
2237     5.8.0 - I've been told they are going to document that it doesn't work in
2238     future.
2240     18. Added an error diagnosis for escapes that PCRE does not support: these are
2241     \L, \l, \N, \P, \p, \U, \u, and \X.
2243     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2244     reading past the end of the pattern in cases such as /[abcd/.
2246     20. PCRE was getting more memory than necessary for patterns with classes that
2247     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2249     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2250     compiling PCRE for use with Virtual Pascal.
2252     22. Small fix to the Makefile to make it work properly if the build is done
2253     outside the source tree.
2255     23. Added a new extension: a condition to go with recursion. If a conditional
2256     subpattern starts with (?(R) the "true" branch is used if recursion has
2257     happened, whereas the "false" branch is used only at the top level.
2259     24. When there was a very long string of literal characters (over 255 bytes
2260     without UTF support, over 250 bytes with UTF support), the computation of how
2261     much memory was required could be incorrect, leading to segfaults or other
2262     strange effects.
2264     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2265     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2266     there was a subsequent back reference to those brackets. This meant that, for
2267     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2268     possible to check for precisely this case. All we can do is abandon the
2269     optimization if .* occurs inside capturing brackets when there are any back
2270     references whatsoever. (See below for a better fix that came later.)
2272     26. The handling of the optimization for finding the first character of a
2273     non-anchored pattern, and for finding a character that is required later in the
2274     match were failing in some cases. This didn't break the matching; it just
2275     failed to optimize when it could. The way this is done has been re-implemented.
2277     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2279     28. Added a new feature that provides some of the functionality that Perl
2280     provides with (?{...}). The facility is termed a "callout". The way it is done
2281     in PCRE is for the caller to provide an optional function, by setting
2282     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2283     global variable. By default it is unset, which disables all calling out. To get
2284     the function called, the regex must include (?C) at appropriate points. This
2285     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2286     This provides a means of identifying different callout points. When PCRE
2287     reaches such a point in the regex, if pcre_callout has been set, the external
2288     function is called. It is provided with data in a structure called
2289     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2290     matching continues; if it returns a non-zero value, the match at the current
2291     point fails. However, backtracking will occur if possible. [This was changed
2292     later and other features added - see item 49 below.]
2294     29. pcretest is upgraded to test the callout functionality. It provides a
2295     callout function that displays information. By default, it shows the start of
2296     the match and the current position in the text. There are some new data escapes
2297     to vary what happens:
2299     \C+ in addition, show current contents of captured substrings
2300     \C- do not supply a callout function
2301     \C!n return 1 when callout number n is reached
2302     \C!n!m return 1 when callout number n is reached for the mth time
2304     30. If pcregrep was called with the -l option and just a single file name, it
2305     output "<stdin>" if a match was found, instead of the file name.
2307     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2308     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2309     pcre_exec(). This saves a malloc/free per call. The default value of
2310     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2311     when configuring.
2313     32. The default maximum size of a compiled pattern is 64K. There have been a
2314     few cases of people hitting this limit. The code now uses macros to handle the
2315     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2316     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2317     configuring. Tests 2 and 5 work only with 2-byte links because they output
2318     debugging information about compiled patterns.
2320     33. Internal code re-arrangements:
2322     (a) Moved the debugging function for printing out a compiled regex into
2323     its own source file (printint.c) and used #include to pull it into
2324     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2325     separate copies.
2327     (b) Defined the list of op-code names for debugging as a macro in
2328     internal.h so that it is next to the definition of the opcodes.
2330     (c) Defined a table of op-code lengths for simpler skipping along compiled
2331     code. This is again a macro in internal.h so that it is next to the
2332     definition of the opcodes.
2334     34. Added support for recursive calls to individual subpatterns, along the
2335     lines of Robin Houston's patch (but implemented somewhat differently).
2337     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2338     allow it to read and process whole directories in Win32. This code was
2339     contributed by Lionel Fourquaux; it has not been tested by me.
2341     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2342     used to name a group. Names consist of alphanumerics and underscores, and must
2343     be unique. Back references use the syntax (?P=name) and recursive calls use
2344     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2345     numbers. The function pcre_fullinfo() can be used after compilation to extract
2346     a name/number map. There are three relevant calls:
2348     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2349     PCRE_INFO_NAMECOUNT yields the number of entries
2350     PCRE_INFO_NAMETABLE yields a pointer to the map.
2352     The map is a vector of fixed-size entries. The size of each entry depends on
2353     the length of the longest name used. The first two bytes of each entry are the
2354     group number, most significant byte first. There follows the corresponding
2355     name, zero terminated. The names are in alphabetical order.
2357     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2358     case instead of 255. Making it the same both with and without UTF-8 support
2359     means that the same test output works with both.
2361     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2362     calling malloc() with a zero argument.
2364     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2365     optimization. I've improved things by keeping a bitmap of backreferences with
2366     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2367     fact referenced, the optimization can be applied. It is unlikely that a
2368     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2369     the match to follow \n) will appear inside brackets with a number greater than
2370     31, but if it does, any back reference > 31 suppresses the optimization.
2372     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2373     of disabling numbered capturing parentheses. Any opening parenthesis that is
2374     not followed by ? behaves as if it were followed by ?: but named parentheses
2375     can still be used for capturing (and they will acquire numbers in the usual
2376     way).
2378     41. Redesigned the return codes from the match() function into yes/no/error so
2379     that errors can be passed back from deep inside the nested calls. A malloc
2380     failure while inside a recursive subpattern call now causes the
2381     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2383     42. It is now possible to set a limit on the number of times the match()
2384     function is called in a call to pcre_exec(). This facility makes it possible to
2385     limit the amount of recursion and backtracking, though not in a directly
2386     obvious way, because the match() function is used in a number of different
2387     circumstances. The count starts from zero for each position in the subject
2388     string (for non-anchored patterns). The default limit is, for compatibility, a
2389     large number, namely 10 000 000. You can change this in two ways:
2391     (a) When configuring PCRE before making, you can use --with-match-limit=n
2392     to set a default value for the compiled library.
2394     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2395     a different value is set. See 45 below.
2397     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2399     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2400     of things that can be changed at compile time. The first argument specifies
2401     what is wanted and the second points to where the information is to be placed.
2402     The current list of available information is:
2406     The output is an integer that is set to one if UTF-8 support is available;
2407     otherwise it is set to zero.
2411     The output is an integer that it set to the value of the code that is used for
2412     newline. It is either LF (10) or CR (13).
2416     The output is an integer that contains the number of bytes used for internal
2417     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2421     The output is an integer that contains the threshold above which the POSIX
2422     interface uses malloc() for output vectors. See item 31 above.
2426     The output is an unsigned integer that contains the default limit of the number
2427     of match() calls in a pcre_exec() execution. See 42 above.
2429     44. pcretest has been upgraded by the addition of the -C option. This causes it
2430     to extract all the available output from the new pcre_config() function, and to
2431     output it. The program then exits immediately.
2433     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2434     order to support additional features. One way would have been to define
2435     pcre_exec2() (for example) with extra arguments, but this would not have been
2436     extensible, and would also have required all calls to the original function to
2437     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2438     is used for passing in "extra" data from pcre_study().
2440     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2441     contains the following fields:
2443     flags a bitmap indicating which of the following fields are set
2444     study_data opaque data from pcre_study()
2445     match_limit a way of specifying a limit on match() calls for a specific
2446     call to pcre_exec()
2447     callout_data data for callouts (see 49 below)
2449     The flag bits are also defined in pcre.h, and are
2455     The pcre_study() function now returns one of these new pcre_extra blocks, with
2456     the actual study data pointed to by the study_data field, and the
2457     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2458     before. That is, this change is entirely upwards-compatible and requires no
2459     change to existing code.
2461     If you want to pass in additional data to pcre_exec(), you can either place it
2462     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2463     block.
2465     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2466     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2467     times with different match limits, until it finds the minimum value needed for
2468     pcre_exec() to complete. The value is then output. This can be instructive; for
2469     most simple matches the number is quite small, but for pathological cases it
2470     gets very large very quickly.
2472     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2473     returns the size of the data block pointed to by the study_data field in a
2474     pcre_extra block, that is, the value that was passed as the argument to
2475     pcre_malloc() when PCRE was getting memory in which to place the information
2476     created by pcre_study(). The fourth argument should point to a size_t variable.
2477     pcretest has been extended so that this information is shown after a successful
2478     pcre_study() call when information about the compiled regex is being displayed.
2480     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2481     because what follows is always an absolute path. (Later: it turns out that this
2482     is more than cosmetic for MinGW, because it doesn't like empty path
2483     components.)
2485     49. Some changes have been made to the callout feature (see 28 above):
2487     (i) A callout function now has three choices for what it returns:
2489     0 => success, carry on matching
2490     > 0 => failure at this point, but backtrack if possible
2491     < 0 => serious error, return this value from pcre_exec()
2493     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2494     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2495     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2496     use by callout functions. It will never be used by PCRE itself.
2498     (ii) The pcre_extra structure (see 45 above) has a void * field called
2499     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2500     pcre_callout_block structure has a field of the same name. The contents of
2501     the field passed in the pcre_extra structure are passed to the callout
2502     function in the corresponding field in the callout block. This makes it
2503     easier to use the same callout-containing regex from multiple threads. For
2504     testing, the pcretest program has a new data escape
2506     \C*n pass the number n (may be negative) as callout_data
2508     If the callout function in pcretest receives a non-zero value as
2509     callout_data, it returns that value.
2511     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2512     there were some redundant $(CFLAGS) in commands that are now specified as
2513     $(LINK), which already includes $(CFLAGS).
2515     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2516     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2517     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2518     one-byte characters throughout. Note that case-insensitive matching applies
2519     only to characters whose values are less than 256. PCRE doesn't support the
2520     notion of cases for higher-valued characters.
2522     (i) A character class whose characters are all within 0-255 is handled as
2523     a bit map, and the map is inverted for negative classes. Previously, a
2524     character > 255 always failed to match such a class; however it should
2525     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2527     (ii) A negated character class with a single character < 255 is coded as
2528     "not this character" (OP_NOT). This wasn't working properly when the test
2529     character was multibyte, either singly or repeated.
2531     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2532     mode, for example: \x{100}{2,3}.
2534     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2535     singly or repeated) now correctly test multibyte characters. However,
2536     PCRE doesn't recognize any characters with values greater than 255 as
2537     digits, spaces, or word characters. Such characters always match \D, \S,
2538     and \W, and never match \d, \s, or \w.
2540     (v) Classes may now contain characters and character ranges with values
2541     greater than 255. For example: [ab\x{100}-\x{400}].
2543     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2544     PCRE in UTF-8 mode.
2546     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2547     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2548     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2549     value.)
2551     53. The single man page has become too large. I have therefore split it up into
2552     a number of separate man pages. These also give rise to individual HTML pages;
2553     these are now put in a separate directory, and there is an index.html page that
2554     lists them all. Some hyperlinking between the pages has been installed.
2556     54. Added convenience functions for handling named capturing parentheses.
2558     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2559     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2560     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2561     are faulted.
2563     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2564     calling configure. These values are used when compiling the dftables.c program
2565     which is run to generate the source of the default character tables. They
2566     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2567     you will need to set these values.
2569     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2572     Version 3.9 02-Jan-02
2573 nigel 61 ---------------------
2575     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2577     2. If --disable-static was given, the building process failed when trying to
2578     build pcretest and pcregrep. (For some reason it was using libtool to compile
2579     them, which is not right, as they aren't part of the library.)
2582 nigel 59 Version 3.8 18-Dec-01
2583     ---------------------
2585     1. The experimental UTF-8 code was completely screwed up. It was packing the
2586     bytes in the wrong order. How dumb can you get?
2589 nigel 57 Version 3.7 29-Oct-01
2590     ---------------------
2592     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2593     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2594     this didn't happen under Solaris 8, where I normally test things.
2596 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2597     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2598     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2599     this fix an hour or so after the initial 3.7 release.)
2600 nigel 57
2601 nigel 59
2602 nigel 55 Version 3.6 23-Oct-01
2603     ---------------------
2605     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2606     offsets passed as NULL with zero offset count.
2608     2. The config.guess and config.sub files had not been updated when I moved to
2609     the latest autoconf.
2612 nigel 53 Version 3.5 15-Aug-01
2613     ---------------------
2614 nigel 5
2615 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2616     had been forgotten.
2618     2. By using declared but undefined structures, we can avoid using "void"
2619     definitions in pcre.h while keeping the internal definitions of the structures
2620     private.
2622     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2623     user point of view, this means that both static and shared libraries are built
2624     by default, but this can be individually controlled. More of the work of
2625     handling this static/shared cases is now inside libtool instead of PCRE's make
2626     file.
2628     4. The pcretest utility is now installed along with pcregrep because it is
2629     useful for users (to test regexs) and by doing this, it automatically gets
2630     relinked by libtool. The documentation has been turned into a man page, so
2631     there are now .1, .txt, and .html versions in /doc.
2633     5. Upgrades to pcregrep:
2634     (i) Added long-form option names like gnu grep.
2635     (ii) Added --help to list all options with an explanatory phrase.
2636     (iii) Added -r, --recursive to recurse into sub-directories.
2637     (iv) Added -f, --file to read patterns from a file.
2639     6. pcre_exec() was referring to its "code" argument before testing that
2640     argument for NULL (and giving an error if it was NULL).
2642     7. Upgraded Makefile.in to allow for compiling in a different directory from
2643     the source directory.
2645     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2646     options bits, the pointer it was passed was to an int instead of to an unsigned
2647     long int. This mattered only on 64-bit systems.
2649     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2650     generated) instead of pcre.in, which it its source. Also made the same change
2651     in several of the .c files.
2653     10. A new release of gcc defines printf() as a macro, which broke pcretest
2654     because it had an ifdef in the middle of a string argument for printf(). Fixed
2655     by using separate calls to printf().
2657     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2658     script, to force use of CR or LF instead of \n in the source. On non-Unix
2659     systems, the value can be set in config.h.
2661     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2662     absolute limit. Changed the text of the error message to make this clear, and
2663     likewise updated the man page.
2665     13. The limit of 99 on the number of capturing subpatterns has been removed.
2666     The new limit is 65535, which I hope will not be a "real" limit.
2669 nigel 51 Version 3.4 22-Aug-00
2670     ---------------------
2672     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2674     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2677 nigel 49 Version 3.3 01-Aug-00
2678     ---------------------
2680     1. If an octal character was given, but the value was greater than \377, it
2681     was not getting masked to the least significant bits, as documented. This could
2682     lead to crashes in some systems.
2684     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2685     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2687     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2688     These just pass their arguments on to (pcre_free)(), but they are provided
2689     because some uses of PCRE bind it to non-C systems that can call its functions,
2690     but cannot call free() or pcre_free() directly.
2692     4. Add "make test" as a synonym for "make check". Corrected some comments in
2693     the Makefile.
2695     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2696     Makefile.
2698     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2699     command called pgrep for grepping around the active processes.
2701     7. Added the beginnings of support for UTF-8 character strings.
2703     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2704     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2705     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2706     out for the ar command.)
2709 nigel 47 Version 3.2 12-May-00
2710     ---------------------
2712     This is purely a bug fixing release.
2714     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2715     of ZA. This was just one example of several cases that could provoke this bug,
2716     which was introduced by change 9 of version 2.00. The code for breaking
2717     infinite loops after an iteration that matches an empty string was't working
2718     correctly.
2720     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2721     when matched against abbab (for example). After matching an empty string, it
2722     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2723     caused it to match further down the string than it should.
2725     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2726     was there because it doesn't seem to be needed, and it causes trouble on some
2727     systems, as it is not a Standard C header. It has been removed.
2729     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2730     were reported on the Macintosh. The changes were from
2732     while ((c = *(++ptr)) != 0 && c != '\n');
2733     to
2734     while ((c = *(++ptr)) != 0 && c != '\n') ;
2736     Totally extraordinary, but if that's what it takes...
2738     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2739     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2740     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2741     assumes the way PCRE uses memmove() (always moving upwards).
2743     6. PCRE is being used in one environment where strchr() is not available. There
2744     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2745     faster code anyway.
2748 nigel 45 Version 3.1 09-Feb-00
2749     ---------------------
2751     The only change in this release is the fixing of some bugs in Makefile.in for
2752     the "install" target:
2754     (1) It was failing to install pcreposix.h.
2756     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2759 nigel 43 Version 3.0 01-Feb-00
2760     ---------------------
2761 nigel 41
2762     1. Add support for the /+ modifier to perltest (to output $` like it does in
2763     pcretest).
2765     2. Add support for the /g modifier to perltest.
2767     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2768     matches null strings.
2770     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2771     pattern. Perl treats empty patterns specially - it reuses the most recent
2772     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2773     effect.
2775     5. The POSIX interface was broken in that it was just handing over the POSIX
2776     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2777     required a bigger vector, with some working space on the end. This means that
2778     the POSIX wrapper now has to get and free some memory, and copy the results.
2780 nigel 43 6. Added some simple autoconf support, placing the test data and the
2781     documentation in separate directories, re-organizing some of the
2782     information files, and making it build pcre-config (a GNU standard). Also added
2783     libtool support for building PCRE as a shared library, which is now the
2784     default.
2785 nigel 41
2786 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2787     09 are not valid octal constants. Single digits will be used for minor values
2788     less than 10.
2790     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2791     existing programs that set these in the POSIX interface can use PCRE without
2792     modification.
2794     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2795     return all that pcre_info() returns, plus additional data. The pcre_info()
2796     function is retained for compatibility, but is considered to be obsolete.
2798     10. Added experimental recursion feature (?R) to handle one common case that
2799     Perl 5.6 will be able to do with (?p{...}).
2801     11. Added support for POSIX character classes like [:alpha:], which Perl is
2802     adopting.
2805 nigel 39 Version 2.08 31-Aug-99
2806     ----------------------
2808     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2809     trying to match at the startoffset position, but instead was moving forward to
2810     the next newline as if a previous match had failed.
2812     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2813     and could get into a loop if a null string was matched other than at the start
2814     of the subject.
2816     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2817     be distinguished at compile time, and for completeness also added PCRE_DATE.
2819     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2820     in GnuWin32 environments.
2823 nigel 37 Version 2.07 29-Jul-99
2824     ----------------------
2826     1. The documentation is now supplied in plain text form and HTML as well as in
2827     the form of man page sources.
2829     2. C++ compilers don't like assigning (void *) values to other pointer types.
2830     In particular this affects malloc(). Although there is no problem in Standard
2831     C, I've put in casts to keep C++ compilers happy.
2833     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2834     should be (const char *).
2836     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2837     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2838     However, I haven't made this a standard facility. The documentation doesn't
2839     mention it, and the Makefile doesn't support it.
2841     5. The Makefile now contains an "install" target, with editable destinations at
2842     the top of the file. The pcretest program is not installed.
2844     6. pgrep -V now gives the PCRE version number and date.
2846     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2847     causing the entire string to be ignored, instead of just the last character.
2849     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2850     non-matching string, it can take a very, very long time, even for strings of
2851     quite modest length, because of the nested recursion. PCRE now does better in
2852     some of these cases. It does this by remembering the last required literal
2853     character in the pattern, and pre-searching the subject to ensure it is present
2854     before running the real match. In other words, it applies a heuristic to detect
2855     some types of certain failure quickly, and in the above example, if presented
2856     with a string that has no trailing " it gives "no match" very quickly.
2858     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2859     other alternatives are tried instead.
2862 nigel 35 Version 2.06 09-Jun-99
2863     ----------------------
2865     1. Change pcretest's output for amount of store used to show just the code
2866     space, because the remainder (the data block) varies in size between 32-bit and
2867     64-bit systems.
2869     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2870     start matching at. This allows lookbehinds to work when searching for multiple
2871     occurrences in a string.
2873     3. Added additional options to pcretest for testing multiple occurrences:
2875     /+ outputs the rest of the string that follows a match
2876     /g loops for multiple occurrences, using the new startoffset argument
2877     /G loops for multiple occurrences by passing an incremented pointer
2879     4. PCRE wasn't doing the "first character" optimization for patterns starting
2880     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2881     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2882     the letter 'x'. On long subject strings, this gives a significant speed-up.
2885 nigel 33 Version 2.05 21-Apr-99
2886     ----------------------
2888     1. Changed the type of magic_number from int to long int so that it works
2889     properly on 16-bit systems.
2891     2. Fixed a bug which caused patterns starting with .* not to work correctly
2892     when the subject string contained newline characters. PCRE was assuming
2893     anchoring for such patterns in all cases, which is not correct because .* will
2894     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2895     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2896     must be retried after every newline in the subject.
2899 nigel 31 Version 2.04 18-Feb-99
2900     ----------------------
2902     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2903     computation of the store needed to hold the pattern was incorrect (too large).
2904     If such patterns were nested a few deep, this could multiply and become a real
2905     problem.
2907     2. Added /M option to pcretest to show the memory requirement of a specific
2908     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2910     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2911     compiled in such a way that the backtracking after subsequent failure was
2912     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2913     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2916 nigel 29 Version 2.03 02-Feb-99
2917     ----------------------
2919     1. Fixed typo and small mistake in man page.
2921 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2922     LICENCE file containing the conditions.
2923 nigel 29
2924     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2925     Perl, that is the internal \ allows the delimiter to be included in the
2926     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2927     the final delimiter, add \ to the end of the pattern (to test the error).
2929     4. Added the convenience functions for extracting substrings after a successful
2930     match. Updated pcretest to make it able to test these functions.
2933 nigel 27 Version 2.02 14-Jan-99
2934     ----------------------
2936     1. Initialized the working variables associated with each extraction so that
2937     their saving and restoring doesn't refer to uninitialized store.
2939     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2940     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2941     fix the problem.
2943     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2944     calls, and wasn't printing the correct value for compiling calls. Increased the
2945     default value of LOOPREPEAT, and the number of significant figures in the
2946     times.
2948     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2950     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2951     a building problem on Windows NT with a FAT file system.
2954 nigel 25 Version 2.01 21-Oct-98
2955     ----------------------
2957     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2958     to character tables built by pcre_maketables() in the current locale. If NULL
2959     is passed, the default tables are used.
2962 nigel 23 Version 2.00 24-Sep-98
2963 nigel 21 ----------------------
2965 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2966     it any more.
2968     2. Allow quantification of (?>) groups, and make it work correctly.
2970     3. The first character computation wasn't working for (?>) groups.
2972     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2973     end of the subject) and add 5.005's \z, which really does match only at the
2974     very end of the subject.
2976     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2978     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2979     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2980     localized options. All options to pcre_study() were also removed.
2982     7. Add other new features from 5.005:
2984     $(?<= positive lookbehind
2985     $(?<! negative lookbehind
2986     (?imsx-imsx) added the unsetting capability
2987     such a setting is global if at outer level; local otherwise
2988     (?imsx-imsx:) non-capturing groups with option setting
2989     (?(cond)re|re) conditional pattern matching
2991     A backreference to itself in a repeated group matches the previous
2992     captured string.
2994     8. General tidying up of studying (both automatic and via "study")
2995     consequential on the addition of new assertions.
2997     9. As in 5.005, unlimited repeated groups that could match an empty substring
2998     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2999     runtime if any iteration does actually match an empty substring.
3001     10. Include the RunTest script in the distribution.
3003     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3004     discrepancies, some of which were old and were also with respect to 5.004. They
3005     have now been fixed.
3008     Version 1.09 28-Apr-98
3009     ----------------------
3011 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3012     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3013     program crashes, or just wrong answers. This did not apply to negated classes
3014     containing more than one character, or to minima other than one.
3017 nigel 19 Version 1.08 27-Mar-98
3018     ----------------------
3020     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3022     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3023     latter must appear before anything that relies on it in the pattern.
3026 nigel 17 Version 1.07 16-Feb-98
3027     ----------------------
3029     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3030     repeat of a potentially empty string).
3033 nigel 15 Version 1.06 23-Jan-98
3034     ----------------------
3036     1. Added Markus Oberhumer's little patches for C++.
3038     2. Literal strings longer than 255 characters were broken.
3041 nigel 13 Version 1.05 23-Dec-97
3042     ----------------------
3044     1. Negated character classes containing more than one character were failing if
3045     PCRE_CASELESS was set at run time.
3048 nigel 11 Version 1.04 19-Dec-97
3049     ----------------------
3051     1. Corrected the man page, where some "const" qualifiers had been omitted.
3053     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3054     input syntax.
3056     3. Fixed memory leak which occurred when a regex with back references was
3057     matched with an offsets vector that wasn't big enough. The temporary memory
3058     that is used in this case wasn't being freed if the match failed.
3060     4. Tidied pcretest to ensure it frees memory that it gets.
3062     5. Temporary memory was being obtained in the case where the passed offsets
3063     vector was exactly big enough.
3065     6. Corrected definition of offsetof() from change 5 below.
3067     7. I had screwed up change 6 below and broken the rules for the use of
3068     setjmp(). Now fixed.
3071 nigel 9 Version 1.03 18-Dec-97
3072     ----------------------
3074     1. A erroneous regex with a missing opening parenthesis was correctly
3075     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3076     on some systems.
3078     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3079     it was reported that one broken compiler failed on the former because "code" is
3080     also an independent variable.
3082     3. The erroneous regex a[]b caused an array overrun reference.
3084     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3085     fail on data ending with that character. (It was going on too far, and checking
3086     the next character, typically a binary zero.) This was specific to the
3087     optimized code for single-character negative classes.
3089     5. Added a contributed patch from the TIN world which does the following:
3091     + Add an undef for memmove, in case the the system defines a macro for it.
3093     + Add a definition of offsetof(), in case there isn't one. (I don't know
3094     the reason behind this - offsetof() is part of the ANSI standard - but
3095     it does no harm).
3097     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3098     most of the places where whitespace preceded '#'. I have given up and
3099     allowed the remaining 2 cases to be at the margin.
3101     + Rename some variables in pcre to eliminate shadowing. This seems very
3102     pedantic, but does no harm, of course.
3104     6. Moved the call to setjmp() into its own function, to get rid of warnings
3105     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3107     7. Constructs such as \d{8,} were compiling into the equivalent of
3108 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3109 nigel 9 outcome, but in this particular case used more store than had been allocated,
3110     which caused the bug to be discovered because it threw up an internal error.
3112     8. The debugging code in both pcre and pcretest for outputting the compiled
3113     form of a regex was going wrong in the case of back references followed by
3114     curly-bracketed repeats.
3117 nigel 7 Version 1.02 12-Dec-97
3118     ----------------------
3120     1. Typos in pcre.3 and comments in the source fixed.
3122     2. Applied a contributed patch to get rid of places where it used to remove
3123     'const' from variables, and fixed some signed/unsigned and uninitialized
3124     variable warnings.
3126     3. Added the "runtest" target to Makefile.
3128     4. Set default compiler flag to -O2 rather than just -O.
3131 nigel 5 Version 1.01 19-Nov-97
3132     ----------------------
3134     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3135     like /([ab]*)*/, that is, for classes with more than one character in them.
3137     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3138     as /((?>a*))*/ (a PCRE_EXTRA facility).
3141     Version 1.00 18-Nov-97
3142     ----------------------
3144     1. Added compile-time macros to support systems such as SunOS4 which don't have
3145     memmove() or strerror() but have other things that can be used instead.
3147     2. Arranged that "make clean" removes the executables.
3150 nigel 3 Version 0.99 27-Oct-97
3151     ----------------------
3153     1. Fixed bug in code for optimizing classes with only one character. It was
3154     initializing a 32-byte map regardless, which could cause it to run off the end
3155     of the memory it had got.
3157     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3160     Version 0.98 22-Oct-97
3161     ----------------------
3163     1. Fixed bug in code for handling temporary memory usage when there are more
3164     back references than supplied space in the ovector. This could cause segfaults.
3167     Version 0.97 21-Oct-97
3168     ----------------------
3170     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3172     2. Optimized negated single characters not to use a bit map.
3174     3. Brought error texts together as macro definitions; clarified some of them;
3175     fixed one that was wrong - it said "range out of order" when it meant "invalid
3176     escape sequence".
3178     4. Changed some char * arguments to const char *.
3180     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3182     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3183     pcretest.
3186     Version 0.96 16-Oct-97
3187     ----------------------
3189     1. Added a simple "pgrep" utility to the distribution.
3191     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3192     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3193     where "ddd" means "one or more decimal digits".
3195     3. Fixed serious bug. If a pattern had a back reference, but the call to
3196     pcre_exec() didn't supply a large enough ovector to record the related
3197     identifying subpattern, the match always failed. PCRE now remembers the number
3198     of the largest back reference, and gets some temporary memory in which to save
3199     the offsets during matching if necessary, in order to ensure that
3200     backreferences always work.
3202     4. Increased the compatibility with Perl in a number of ways:
3204     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3205     to request this handling. The option can be set at compile or exec time.
3207     (b) $ matches before a terminating newline by default; an option
3208     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3209     mode). The option can be set at compile or exec time.
3211     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3212     the same as Perl's. If the decimal number it represents is less than 10
3213     or there aren't that many previous left capturing parentheses, an octal
3214     escape is read. Inside a character class, it's always an octal escape,
3215     even if it is a single digit.
3217     (d) An escaped but undefined alphabetic character is taken as a literal,
3218     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3219     escapes.
3221     (e) {0} is now permitted. (The previous item is removed from the compiled
3222     pattern).
3224     5. Changed all the names of code files so that the basic parts are no longer
3225     than 10 characters, and abolished the teeny "globals.c" file.
3227     6. Changed the handling of character classes; they are now done with a 32-byte
3228     bit map always.
3230     7. Added the -d and /D options to pcretest to make it possible to look at the
3231     internals of compilation without having to recompile pcre.
3234     Version 0.95 23-Sep-97
3235     ----------------------
3237     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3238     \x20 at the start of a run of normal characters. These were being treated as
3239     real characters, instead of the source characters being re-checked.
3242     Version 0.94 18-Sep-97
3243     ----------------------
3245     1. The functions are now thread-safe, with the caveat that the global variables
3246     containing pointers to malloc() and free() or alternative functions are the
3247     same for all threads.
3249     2. Get pcre_study() to generate a bitmap of initial characters for non-
3250     anchored patterns when this is possible, and use it if passed to pcre_exec().
3253     Version 0.93 15-Sep-97
3254     ----------------------
3256     1. /(b)|(:+)/ was computing an incorrect first character.
3258     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3259     but not actually doing anything yet.
3261     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3262     as Perl does (e.g. [-az] or [az-]).
3264     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3265     all possible positions.
3267     5. Split up into different modules to avoid including unneeded functions in a
3268     compiled binary. However, compile and exec are still in one module. The "study"
3269     function is split off.
3271     6. The character tables are now in a separate module whose source is generated
3272     by an auxiliary program - but can then be edited by hand if required. There are
3273     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3274     toupper() in the code.
3276     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3277     make them global. Abolish the function for setting them, as the caller can now
3278     set them directly.
3281     Version 0.92 11-Sep-97
3282     ----------------------
3284     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3285     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3287     2. Caseless matching was not working in character classes if the characters in
3288     the pattern were in upper case.
3290     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3292     4. Make PCRE_ANCHORED public and accept as a compile option.
3294     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3295     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3296     pass them.
3298     6. Give an error if bad option bits passed at compile or run time.
3300     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3301     pcretest to cause it to pass that flag.
3303     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3304     options, and the first character, if set.
3306     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3309     Version 0.91 10-Sep-97
3310     ----------------------
3312     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3313     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3315     2. PCRE was looping on encountering an indefinitely repeated back reference to
3316     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3317     Perl does - treats the match as successful.
3319     ****


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