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Revision 357 - (show annotations) (download)
Tue Jul 8 14:18:28 2008 UTC (6 years, 1 month ago) by ph10
File size: 157558 byte(s)
Added two (int) casts to pcregrep.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.0 02 Jul-08
5 ---------------------
6
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).
13
14 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15 scripts.
16
17 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18 a group with a zero qualifier. The result of the study could be incorrect,
19 or the function might crash, depending on the pattern.
20
21 4. Caseless matching was not working for non-ASCII characters in back
22 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23 It now works when Unicode Property Support is available.
24
25 5. In pcretest, an escape such as \x{de} in the data was always generating
26 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28 truncation.
29
30 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
31
32 7. Added two (int) casts to pcregrep when printing the difference of two
33 pointers, in case they are 64-bit values.
34
35
36 Version 7.7 07-May-08
37 ---------------------
38
39 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
40 a string to a long long, pretend we don't even have a long long." This is
41 done by checking for the strtoq, strtoll, and _strtoi64 functions.
42
43 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
44 pre-7.6 versions, which defined a global no_arg variable instead of putting
45 it in the RE class. (See also #8 below.)
46
47 3. Remove a line of dead code, identified by coverity and reported by Nuno
48 Lopes.
49
50 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
51
52 (1) The include/exclude patterns were being applied to the whole pathnames
53 of files, instead of just to the final components.
54
55 (2) If there was more than one level of directory, the subdirectories were
56 skipped unless they satisfied the include/exclude conditions. This is
57 inconsistent with GNU grep (and could even be seen as contrary to the
58 pcregrep specification - which I improved to make it absolutely clear).
59 The action now is always to scan all levels of directory, and just
60 apply the include/exclude patterns to regular files.
61
62 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
63 --exclude_dir in the tests to avoid scanning .svn directories.
64
65 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
66 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
67 doesn't support NULs in patterns.
68
69 7. Added some missing "const"s to declarations of static tables in
70 pcre_compile.c and pcre_dfa_exec.c.
71
72 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
73 caused by fix #2 above. (Subsequently also a second patch to fix the
74 first patch. And a third patch - this was a messy problem.)
75
76 9. Applied Craig's patch to remove the use of push_back().
77
78 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
79 matching function regexec().
80
81 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
82 which, however, unlike Perl's \g{...}, are subroutine calls, not back
83 references. PCRE supports relative numbers with this syntax (I don't think
84 Oniguruma does).
85
86 12. Previously, a group with a zero repeat such as (...){0} was completely
87 omitted from the compiled regex. However, this means that if the group
88 was called as a subroutine from elsewhere in the pattern, things went wrong
89 (an internal error was given). Such groups are now left in the compiled
90 pattern, with a new opcode that causes them to be skipped at execution
91 time.
92
93 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
94 to the way PCRE behaves:
95
96 (a) A lone ] character is dis-allowed (Perl treats it as data).
97
98 (b) A back reference to an unmatched subpattern matches an empty string
99 (Perl fails the current match path).
100
101 (c) A data ] in a character class must be notated as \] because if the
102 first data character in a class is ], it defines an empty class. (In
103 Perl it is not possible to have an empty class.) The empty class []
104 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
105 The negative empty class [^] matches any one character, independently
106 of the DOTALL setting.
107
108 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
109 non-existent subpattern following a character class starting with ']' and
110 containing () gave an internal compiling error instead of "reference to
111 non-existent subpattern". Fortunately, when the pattern did exist, the
112 compiled code was correct. (When scanning forwards to check for the
113 existencd of the subpattern, it was treating the data ']' as terminating
114 the class, so got the count wrong. When actually compiling, the reference
115 was subsequently set up correctly.)
116
117 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
118 it was being rejected as not supported by pcre_dfa_exec(), even though
119 other assertions are supported. I have made pcre_dfa_exec() support
120 (*FAIL).
121
122 16. The implementation of 13c above involved the invention of a new opcode,
123 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
124 cannot be changed at match time, I realized I could make a small
125 improvement to matching performance by compiling OP_ALLANY instead of
126 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
127 on the OP_ANY path.
128
129 17. Compiling pcretest on Windows with readline support failed without the
130 following two fixes: (1) Make the unistd.h include conditional on
131 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
132
133 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
134 ncurses library to be included for pcretest when ReadLine support is
135 requested, but also to allow for it to be overridden. This patch came from
136 Daniel Bergström.
137
138 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
139 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
140 any errors with the current Unicode tables. Thanks to Peter Kankowski for
141 spotting this.
142
143
144 Version 7.6 28-Jan-08
145 ---------------------
146
147 1. A character class containing a very large number of characters with
148 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
149 overflow.
150
151 2. Patch to cut out the "long long" test in pcrecpp_unittest when
152 HAVE_LONG_LONG is not defined.
153
154 3. Applied Christian Ehrlicher's patch to update the CMake build files to
155 bring them up to date and include new features. This patch includes:
156
157 - Fixed PH's badly added libz and libbz2 support.
158 - Fixed a problem with static linking.
159 - Added pcredemo. [But later removed - see 7 below.]
160 - Fixed dftables problem and added an option.
161 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
162 HAVE_LONG_LONG.
163 - Added readline support for pcretest.
164 - Added an listing of the option settings after cmake has run.
165
166 4. A user submitted a patch to Makefile that makes it easy to create
167 "pcre.dll" under mingw when using Configure/Make. I added stuff to
168 Makefile.am that cause it to include this special target, without
169 affecting anything else. Note that the same mingw target plus all
170 the other distribution libraries and programs are now supported
171 when configuring with CMake (see 6 below) instead of with
172 Configure/Make.
173
174 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
175 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
176 exported in the Windows port". It has not yet been confirmed that the patch
177 solves the problem, but it does no harm.
178
179 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
180 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
181 with CMake, and also correct the comment about stack recursion.
182
183 7. Remove the automatic building of pcredemo from the ./configure system and
184 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
185 of a program that users should build themselves after PCRE is installed, so
186 building it automatically is not really right. What is more, it gave
187 trouble in some build environments.
188
189 8. Further tidies to CMakeLists.txt from Sheri and Christian.
190
191
192 Version 7.5 10-Jan-08
193 ---------------------
194
195 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
196 values in parens when parsing an RE using the C++ wrapper."
197
198 2. Negative specials like \S did not work in character classes in UTF-8 mode.
199 Characters greater than 255 were excluded from the class instead of being
200 included.
201
202 3. The same bug as (2) above applied to negated POSIX classes such as
203 [:^space:].
204
205 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
206 defined or documented. It seems to have been a typo for PCRE_STATIC, so
207 I have changed it.
208
209 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
210 first named subpattern) and a construct such as (?&a) would reference the
211 first named subpattern whose name started with "a" (in other words, the
212 length check was missing). Both these problems are fixed. "Subpattern name
213 expected" is now given for (?&) (a zero-length name), and this patch also
214 makes it give the same error for \k'' (previously it complained that that
215 was a reference to a non-existent subpattern).
216
217 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
218 this is right because (?- can be followed by option settings as well as by
219 digits. I have, however, made the messages clearer.
220
221 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
222 than the number used in the conditional) now cause a compile-time error.
223 This is actually not compatible with Perl, which accepts such patterns, but
224 treats the conditional as always being FALSE (as PCRE used to), but it
225 seems to me that giving a diagnostic is better.
226
227 8. Change "alphameric" to the more common word "alphanumeric" in comments
228 and messages.
229
230 9. Fix two occurrences of "backslash" in comments that should have been
231 "backspace".
232
233 10. Remove two redundant lines of code that can never be obeyed (their function
234 was moved elsewhere).
235
236 11. The program that makes PCRE's Unicode character property table had a bug
237 which caused it to generate incorrect table entries for sequences of
238 characters that have the same character type, but are in different scripts.
239 It amalgamated them into a single range, with the script of the first of
240 them. In other words, some characters were in the wrong script. There were
241 thirteen such cases, affecting characters in the following ranges:
242
243 U+002b0 - U+002c1
244 U+0060c - U+0060d
245 U+0061e - U+00612
246 U+0064b - U+0065e
247 U+0074d - U+0076d
248 U+01800 - U+01805
249 U+01d00 - U+01d77
250 U+01d9b - U+01dbf
251 U+0200b - U+0200f
252 U+030fc - U+030fe
253 U+03260 - U+0327f
254 U+0fb46 - U+0fbb1
255 U+10450 - U+1049d
256
257 12. The -o option (show only the matching part of a line) for pcregrep was not
258 compatible with GNU grep in that, if there was more than one match in a
259 line, it showed only the first of them. It now behaves in the same way as
260 GNU grep.
261
262 13. If the -o and -v options were combined for pcregrep, it printed a blank
263 line for every non-matching line. GNU grep prints nothing, and pcregrep now
264 does the same. The return code can be used to tell if there were any
265 non-matching lines.
266
267 14. Added --file-offsets and --line-offsets to pcregrep.
268
269 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
270 infinitely looping recursion. The bug was that positive lookaheads were not
271 being skipped when checking for a possible empty match (negative lookaheads
272 and both kinds of lookbehind were skipped).
273
274 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
275 inclusion of <windows.h> to before rather than after the definition of
276 INVALID_FILE_ATTRIBUTES (patch from David Byron).
277
278 17. Specifying a possessive quantifier with a specific limit for a Unicode
279 character property caused pcre_compile() to compile bad code, which led at
280 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
281 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
282 caused the error; without that there was no problem.
283
284 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
285
286 19. Added --enable-pcretest-libreadline.
287
288 20. In pcrecpp.cc, the variable 'count' was incremented twice in
289 RE::GlobalReplace(). As a result, the number of replacements returned was
290 double what it should be. I removed one of the increments, but Craig sent a
291 later patch that removed the other one (the right fix) and added unit tests
292 that check the return values (which was not done before).
293
294 21. Several CMake things:
295
296 (1) Arranged that, when cmake is used on Unix, the libraries end up with
297 the names libpcre and libpcreposix, not just pcre and pcreposix.
298
299 (2) The above change means that pcretest and pcregrep are now correctly
300 linked with the newly-built libraries, not previously installed ones.
301
302 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
303
304 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
305 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
306 UTF-8 newline character). The key issue is that the pattern starts .*;
307 this means that the match must be either at the beginning, or after a
308 newline. The bug was in the code for advancing after a failed match and
309 checking that the new position followed a newline. It was not taking
310 account of UTF-8 characters correctly.
311
312 23. PCRE was behaving differently from Perl in the way it recognized POSIX
313 character classes. PCRE was not treating the sequence [:...:] as a
314 character class unless the ... were all letters. Perl, however, seems to
315 allow any characters between [: and :], though of course it rejects as
316 unknown any "names" that contain non-letters, because all the known class
317 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
318 for example, whereas PCRE did not - it did not recognize a POSIX character
319 class. This seemed a bit dangerous, so the code has been changed to be
320 closer to Perl. The behaviour is not identical to Perl, because PCRE will
321 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
322 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
323 Perl does, and where it didn't before.
324
325 24. Rewrite so as to remove the single use of %n from pcregrep because in some
326 Windows environments %n is disabled by default.
327
328
329 Version 7.4 21-Sep-07
330 ---------------------
331
332 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
333 means that a class such as [\s] counted as "explicit reference to CR or
334 LF". That isn't really right - the whole point of the change was to try to
335 help when there was an actual mention of one of the two characters. So now
336 the change happens only if \r or \n (or a literal CR or LF) character is
337 encountered.
338
339 2. The 32-bit options word was also used for 6 internal flags, but the numbers
340 of both had grown to the point where there were only 3 bits left.
341 Fortunately, there was spare space in the data structure, and so I have
342 moved the internal flags into a new 16-bit field to free up more option
343 bits.
344
345 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
346 but did not set the internal JCHANGED flag - either of these is enough to
347 control the way the "get" function works - but the PCRE_INFO_JCHANGED
348 facility is supposed to tell if (?J) was ever used, so now (?J) at the
349 start sets both bits.
350
351 4. Added options (at build time, compile time, exec time) to change \R from
352 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
353
354 5. doc/pcresyntax.html was missing from the distribution.
355
356 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
357 compatibility, even though it is no longer used.
358
359 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
360 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
361 windows.h file is present (where different names are used). [This was
362 reversed later after testing - see 16 below.]
363
364 8. Changed all #include <config.h> to #include "config.h". There were also
365 some further <pcre.h> cases that I changed to "pcre.h".
366
367 9. When pcregrep was used with the --colour option, it missed the line ending
368 sequence off the lines that it output.
369
370 10. It was pointed out to me that arrays of string pointers cause lots of
371 relocations when a shared library is dynamically loaded. A technique of
372 using a single long string with a table of offsets can drastically reduce
373 these. I have refactored PCRE in four places to do this. The result is
374 dramatic:
375
376 Originally: 290
377 After changing UCP table: 187
378 After changing error message table: 43
379 After changing table of "verbs" 36
380 After changing table of Posix names 22
381
382 Thanks to the folks working on Gregex for glib for this insight.
383
384 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
385 unicode-properties was also set.
386
387 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
388
389 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
390 checked only for CRLF.
391
392 14. Added casts to pcretest.c to avoid compiler warnings.
393
394 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
395
396 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
397 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
398 entirely. This removes changes made in 7 above.
399
400 17. The CMake files have been updated, and there is now more information about
401 building with CMake in the NON-UNIX-USE document.
402
403
404 Version 7.3 28-Aug-07
405 ---------------------
406
407 1. In the rejigging of the build system that eventually resulted in 7.1, the
408 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
409 brackets there is not right, since it causes compilers to look for an
410 installed pcre.h, not the version that is in the source that is being
411 compiled (which of course may be different). I have changed it back to:
412
413 #include "pcre.h"
414
415 I have a vague recollection that the change was concerned with compiling in
416 different directories, but in the new build system, that is taken care of
417 by the VPATH setting the Makefile.
418
419 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
420 when the subject happened to end in the byte 0x85 (e.g. if the last
421 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
422 characters but of course it shouldn't be taken as a newline when it is part
423 of another character. The bug was that, for an unlimited repeat of . in
424 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
425 characters when looking for a newline.
426
427 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
428
429 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
430 in debug output.
431
432 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
433 long printing in the pcrecpp unittest when running under MinGW.
434
435 6. ESC_K was left out of the EBCDIC table.
436
437 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
438 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
439 limit also applies to "virtual nesting" when a pattern is recursive, and in
440 this case 1000 isn't so big. I have been able to remove this limit at the
441 expense of backing off one optimization in certain circumstances. Normally,
442 when pcre_exec() would call its internal match() function recursively and
443 immediately return the result unconditionally, it uses a "tail recursion"
444 feature to save stack. However, when a subpattern that can match an empty
445 string has an unlimited repetition quantifier, it no longer makes this
446 optimization. That gives it a stack frame in which to save the data for
447 checking that an empty string has been matched. Previously this was taken
448 from the 1000-entry workspace that had been reserved. So now there is no
449 explicit limit, but more stack is used.
450
451 8. Applied Daniel's patches to solve problems with the import/export magic
452 syntax that is required for Windows, and which was going wrong for the
453 pcreposix and pcrecpp parts of the library. These were overlooked when this
454 problem was solved for the main library.
455
456 9. There were some crude static tests to avoid integer overflow when computing
457 the size of patterns that contain repeated groups with explicit upper
458 limits. As the maximum quantifier is 65535, the maximum group length was
459 set at 30,000 so that the product of these two numbers did not overflow a
460 32-bit integer. However, it turns out that people want to use groups that
461 are longer than 30,000 bytes (though not repeat them that many times).
462 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
463 made it possible to implement the integer overflow checks in a much more
464 dynamic way, which I have now done. The artificial limitation on group
465 length has been removed - we now have only the limit on the total length of
466 the compiled pattern, which depends on the LINK_SIZE setting.
467
468 10. Fixed a bug in the documentation for get/copy named substring when
469 duplicate names are permitted. If none of the named substrings are set, the
470 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
471 empty string.
472
473 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
474 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
475 because the ] is interpreted as the first data character and the
476 terminating ] is not found. PCRE has been made compatible with Perl in this
477 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
478 cause memory overwriting.
479
480 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
481 string has been matched (to stop an infinite loop). It was not recognizing
482 a conditional subpattern that could match an empty string if that
483 subpattern was within another subpattern. For example, it looped when
484 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
485 condition was not nested. This bug has been fixed.
486
487 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
488 past the start of the subject in the presence of bytes with the top bit
489 set, for example "\x8aBCD".
490
491 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
492 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
493
494 14. Optimized (?!) to (*FAIL).
495
496 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
497 This restricts code points to be within the range 0 to 0x10FFFF, excluding
498 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
499 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
500 does: it's just the validity check that is more restrictive.
501
502 16. Inserted checks for integer overflows during escape sequence (backslash)
503 processing, and also fixed erroneous offset values for syntax errors during
504 backslash processing.
505
506 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
507 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
508
509 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
510 caused an overrun.
511
512 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
513 something other than just ASCII characters) inside a group that had an
514 unlimited repeat caused a loop at compile time (while checking to see
515 whether the group could match an empty string).
516
517 20. Debugging a pattern containing \p or \P could cause a crash. For example,
518 [\P{Any}] did so. (Error in the code for printing property names.)
519
520 21. An orphan \E inside a character class could cause a crash.
521
522 22. A repeated capturing bracket such as (A)? could cause a wild memory
523 reference during compilation.
524
525 23. There are several functions in pcre_compile() that scan along a compiled
526 expression for various reasons (e.g. to see if it's fixed length for look
527 behind). There were bugs in these functions when a repeated \p or \P was
528 present in the pattern. These operators have additional parameters compared
529 with \d, etc, and these were not being taken into account when moving along
530 the compiled data. Specifically:
531
532 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
533 length.
534
535 (b) An item such as \pL+ within a repeated group could cause crashes or
536 loops.
537
538 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
539 "reference to non-existent subpattern" error.
540
541 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
542
543 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
544 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
545
546 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
547
548 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
549 character were causing crashes (broken optimization).
550
551 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
552 \p or \P) caused a compile-time loop.
553
554 28. More problems have arisen in unanchored patterns when CRLF is a valid line
555 break. For example, the unstudied pattern [\r\n]A does not match the string
556 "\r\nA" because change 7.0/46 below moves the current point on by two
557 characters after failing to match at the start. However, the pattern \nA
558 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
559 the same is true. There doesn't seem any very clean way out of this, but
560 what I have chosen to do makes the common cases work: PCRE now takes note
561 of whether there can be an explicit match for \r or \n anywhere in the
562 pattern, and if so, 7.0/46 no longer applies. As part of this change,
563 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
564 pattern has explicit CR or LF references.
565
566 29. Added (*CR) etc for changing newline setting at start of pattern.
567
568
569 Version 7.2 19-Jun-07
570 ---------------------
571
572 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
573 which is apparently normally available under Windows.
574
575 2. Re-jig the pcregrep tests with different newline settings in an attempt
576 to make them independent of the local environment's newline setting.
577
578 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
579
580 4. Some of the "internals" tests were previously cut out when the link size
581 was not 2, because the output contained actual offsets. The recent new
582 "Z" feature of pcretest means that these can be cut out, making the tests
583 usable with all link sizes.
584
585 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
586 stack recursion. This gives a massive performance boost under BSD, but just
587 a small improvement under Linux. However, it saves one field in the frame
588 in all cases.
589
590 6. Added more features from the forthcoming Perl 5.10:
591
592 (a) (?-n) (where n is a string of digits) is a relative subroutine or
593 recursion call. It refers to the nth most recently opened parentheses.
594
595 (b) (?+n) is also a relative subroutine call; it refers to the nth next
596 to be opened parentheses.
597
598 (c) Conditions that refer to capturing parentheses can be specified
599 relatively, for example, (?(-2)... or (?(+3)...
600
601 (d) \K resets the start of the current match so that everything before
602 is not part of it.
603
604 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
605
606 (f) \g{name} is another synonym - part of Perl 5.10's unification of
607 reference syntax.
608
609 (g) (?| introduces a group in which the numbering of parentheses in each
610 alternative starts with the same number.
611
612 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
613
614 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
615 PCRE_INFO_JCHANGED.
616
617 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
618 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
619 for detecting groups that can match an empty string.
620
621 9. A pattern with a very large number of alternatives (more than several
622 hundred) was running out of internal workspace during the pre-compile
623 phase, where pcre_compile() figures out how much memory will be needed. A
624 bit of new cunning has reduced the workspace needed for groups with
625 alternatives. The 1000-alternative test pattern now uses 12 bytes of
626 workspace instead of running out of the 4096 that are available.
627
628 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
629
630 11. Applied patch from Google to remove an optimization that didn't quite work.
631 The report of the bug said:
632
633 pcrecpp::RE("a*").FullMatch("aaa") matches, while
634 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
635 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
636
637 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
638 it matched the wrong number of bytes.
639
640
641 Version 7.1 24-Apr-07
642 ---------------------
643
644 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
645 that is more "standard", making use of automake and other Autotools. There
646 is some re-arrangement of the files and adjustment of comments consequent
647 on this.
648
649 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
650 for recursive directory scanning broke on some systems because the files
651 are not scanned in any specific order and on different systems the order
652 was different. A call to "sort" has been inserted into RunGrepTest for the
653 approprate test as a short-term fix. In the longer term there may be an
654 alternative.
655
656 3. I had an email from Eric Raymond about problems translating some of PCRE's
657 man pages to HTML (despite the fact that I distribute HTML pages, some
658 people do their own conversions for various reasons). The problems
659 concerned the use of low-level troff macros .br and .in. I have therefore
660 removed all such uses from the man pages (some were redundant, some could
661 be replaced by .nf/.fi pairs). The 132html script that I use to generate
662 HTML has been updated to handle .nf/.fi and to complain if it encounters
663 .br or .in.
664
665 4. Updated comments in configure.ac that get placed in config.h.in and also
666 arranged for config.h to be included in the distribution, with the name
667 config.h.generic, for the benefit of those who have to compile without
668 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
669
670 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
671 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
672 makevp.bat for the current PCRE, using the additional files
673 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
674
675 6. A Windows user reported a minor discrepancy with test 2, which turned out
676 to be caused by a trailing space on an input line that had got lost in his
677 copy. The trailing space was an accident, so I've just removed it.
678
679 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
680 that is needed.
681
682 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
683 as "const" (a) because they are and (b) because it helps the PHP
684 maintainers who have recently made a script to detect big data structures
685 in the php code that should be moved to the .rodata section. I remembered
686 to update Builducptable as well, so it won't revert if ucptable.h is ever
687 re-created.
688
689 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
690 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
691 order to be able to cut out the UTF-8 tables in the latter when UTF-8
692 support is not required. This saves 1.5-2K of code, which is important in
693 some applications.
694
695 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
696 so as not to refer to the tables, even though these functions will never be
697 called when UTF-8 support is disabled. Otherwise there are problems with a
698 shared library.
699
700 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
701
702 (a) It was defining its arguments as char * instead of void *.
703
704 (b) It was assuming that all moves were upwards in memory; this was true
705 a long time ago when I wrote it, but is no longer the case.
706
707 The emulated memove() is provided for those environments that have neither
708 memmove() nor bcopy(). I didn't think anyone used it these days, but that
709 is clearly not the case, as these two bugs were recently reported.
710
711 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
712 and Detrail to create the HTML documentation, the .txt form of the man
713 pages, and it removes trailing spaces from listed files. It also creates
714 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
715 case, it wraps all the #defines with #ifndefs. This script should be run
716 before "make dist".
717
718 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
719 with Unicode property support.
720
721 (a) For a maximizing quantifier, if the two different cases of the
722 character were of different lengths in their UTF-8 codings (there are
723 some cases like this - I found 11), and the matching function had to
724 back up over a mixture of the two cases, it incorrectly assumed they
725 were both the same length.
726
727 (b) When PCRE was configured to use the heap rather than the stack for
728 recursion during matching, it was not correctly preserving the data for
729 the other case of a UTF-8 character when checking ahead for a match
730 while processing a minimizing repeat. If the check also involved
731 matching a wide character, but failed, corruption could cause an
732 erroneous result when trying to check for a repeat of the original
733 character.
734
735 13. Some tidying changes to the testing mechanism:
736
737 (a) The RunTest script now detects the internal link size and whether there
738 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
739 values substituted by "configure". (The RunGrepTest script already did
740 this for UTF-8.) The configure.ac script no longer substitutes the
741 relevant variables.
742
743 (b) The debugging options /B and /D in pcretest show the compiled bytecode
744 with length and offset values. This means that the output is different
745 for different internal link sizes. Test 2 is skipped for link sizes
746 other than 2 because of this, bypassing the problem. Unfortunately,
747 there was also a test in test 3 (the locale tests) that used /B and
748 failed for link sizes other than 2. Rather than cut the whole test out,
749 I have added a new /Z option to pcretest that replaces the length and
750 offset values with spaces. This is now used to make test 3 independent
751 of link size. (Test 2 will be tidied up later.)
752
753 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
754 segmentation fault instead of returning the appropriate error message.
755
756 15. In multiline mode when the newline sequence was set to "any", the pattern
757 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
758 This doesn't seem right; it now treats the CRLF combination as the line
759 ending, and so does not match in that case. It's only a pattern such as ^$
760 that would hit this one: something like ^ABC$ would have failed after \r
761 and then tried again after \r\n.
762
763 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
764 in an attempt to make files that differ only in their line terminators
765 compare equal. This works on Linux.
766
767 17. Under certain error circumstances pcregrep might try to free random memory
768 as it exited. This is now fixed, thanks to valgrind.
769
770 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
771 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
772 was because its rules for how to advance for /g after matching an empty
773 string at the end of a line did not allow for this case. They now check for
774 it specially.
775
776 20. pcretest is supposed to handle patterns and data of any length, by
777 extending its buffers when necessary. It was getting this wrong when the
778 buffer for a data line had to be extended.
779
780 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
781 CRLF as a newline sequence.
782
783 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
784 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
785 I have nevertheless tidied it up.
786
787 23. Added some casts to kill warnings from HP-UX ia64 compiler.
788
789 24. Added a man page for pcre-config.
790
791
792 Version 7.0 19-Dec-06
793 ---------------------
794
795 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
796 moving to gcc 4.1.1.
797
798 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
799 sys/time.h, which is documented as needed for this function. It doesn't
800 seem to matter on Linux, but it showed up on some releases of OS X.
801
802 3. It seems that there are systems where bytes whose values are greater than
803 127 match isprint() in the "C" locale. The "C" locale should be the
804 default when a C program starts up. In most systems, only ASCII printing
805 characters match isprint(). This difference caused the output from pcretest
806 to vary, making some of the tests fail. I have changed pcretest so that:
807
808 (a) When it is outputting text in the compiled version of a pattern, bytes
809 other than 32-126 are always shown as hex escapes.
810
811 (b) When it is outputting text that is a matched part of a subject string,
812 it does the same, unless a different locale has been set for the match
813 (using the /L modifier). In this case, it uses isprint() to decide.
814
815 4. Fixed a major bug that caused incorrect computation of the amount of memory
816 required for a compiled pattern when options that changed within the
817 pattern affected the logic of the preliminary scan that determines the
818 length. The relevant options are -x, and -i in UTF-8 mode. The result was
819 that the computed length was too small. The symptoms of this bug were
820 either the PCRE error "internal error: code overflow" from pcre_compile(),
821 or a glibc crash with a message such as "pcretest: free(): invalid next
822 size (fast)". Examples of patterns that provoked this bug (shown in
823 pcretest format) are:
824
825 /(?-x: )/x
826 /(?x)(?-x: \s*#\s*)/
827 /((?i)[\x{c0}])/8
828 /(?i:[\x{c0}])/8
829
830 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
831 is now done differently.
832
833 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
834 wrapper classes; (b) implement a new function in the C++ scanner that is
835 more efficient than the old way of doing things because it avoids levels of
836 recursion in the regex matching; (c) add a paragraph to the documentation
837 for the FullMatch() function.
838
839 6. The escape sequence \n was being treated as whatever was defined as
840 "newline". Not only was this contrary to the documentation, which states
841 that \n is character 10 (hex 0A), but it also went horribly wrong when
842 "newline" was defined as CRLF. This has been fixed.
843
844 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
845 was being set to -1 for the "end of line" case (supposedly a value that no
846 character can have). Though this value is never used (the check for end of
847 line is "zero bytes in current character"), it caused compiler complaints.
848 I've changed it to 0xffffffff.
849
850 8. In pcre_version.c, the version string was being built by a sequence of
851 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
852 string (as it is for production releases) called a macro with an empty
853 argument. The C standard says the result of this is undefined. The gcc
854 compiler treats it as an empty string (which was what was wanted) but it is
855 reported that Visual C gives an error. The source has been hacked around to
856 avoid this problem.
857
858 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
859 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
860 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
861 of them did).
862
863 10. Originally, pcretest opened its input and output without "b"; then I was
864 told that "b" was needed in some environments, so it was added for release
865 5.0 to both the input and output. (It makes no difference on Unix-like
866 systems.) Later I was told that it is wrong for the input on Windows. I've
867 now abstracted the modes into two macros, to make it easier to fiddle with
868 them, and removed "b" from the input mode under Windows.
869
870 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
871
872 12. Added -help and --help to pcretest as an official way of being reminded
873 of the options.
874
875 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
876 and pcrecpp.cc because they annoy compilers at high warning levels.
877
878 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
879
880 15. Fixed an occurrence of == in configure.ac that should have been = (shell
881 scripts are not C programs :-) and which was not noticed because it works
882 on Linux.
883
884 16. pcretest is supposed to handle any length of pattern and data line (as one
885 line or as a continued sequence of lines) by extending its input buffer if
886 necessary. This feature was broken for very long pattern lines, leading to
887 a string of junk being passed to pcre_compile() if the pattern was longer
888 than about 50K.
889
890 17. I have done a major re-factoring of the way pcre_compile() computes the
891 amount of memory needed for a compiled pattern. Previously, there was code
892 that made a preliminary scan of the pattern in order to do this. That was
893 OK when PCRE was new, but as the facilities have expanded, it has become
894 harder and harder to keep it in step with the real compile phase, and there
895 have been a number of bugs (see for example, 4 above). I have now found a
896 cunning way of running the real compile function in a "fake" mode that
897 enables it to compute how much memory it would need, while actually only
898 ever using a few hundred bytes of working memory and without too many
899 tests of the mode. This should make future maintenance and development
900 easier. A side effect of this work is that the limit of 200 on the nesting
901 depth of parentheses has been removed (though this was never a serious
902 limitation, I suspect). However, there is a downside: pcre_compile() now
903 runs more slowly than before (30% or more, depending on the pattern). I
904 hope this isn't a big issue. There is no effect on runtime performance.
905
906 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
907 newline (only possible for the last line of a file) and it was a
908 pattern that set a locale (followed by /Lsomething), pcretest crashed.
909
910 19. Added additional timing features to pcretest. (1) The -tm option now times
911 matching only, not compiling. (2) Both -t and -tm can be followed, as a
912 separate command line item, by a number that specifies the number of
913 repeats to use when timing. The default is 50000; this gives better
914 precision, but takes uncomfortably long for very large patterns.
915
916 20. Extended pcre_study() to be more clever in cases where a branch of a
917 subpattern has no definite first character. For example, (a*|b*)[cd] would
918 previously give no result from pcre_study(). Now it recognizes that the
919 first character must be a, b, c, or d.
920
921 21. There was an incorrect error "recursive call could loop indefinitely" if
922 a subpattern (or the entire pattern) that was being tested for matching an
923 empty string contained only one non-empty item after a nested subpattern.
924 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
925 incorrectly, because the \d was being skipped in the check.
926
927 22. The pcretest program now has a new pattern option /B and a command line
928 option -b, which is equivalent to adding /B to every pattern. This causes
929 it to show the compiled bytecode, without the additional information that
930 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
931 is the same as /B/I).
932
933 23. A new optimization is now able automatically to treat some sequences such
934 as a*b as a*+b. More specifically, if something simple (such as a character
935 or a simple class like \d) has an unlimited quantifier, and is followed by
936 something that cannot possibly match the quantified thing, the quantifier
937 is automatically "possessified".
938
939 24. A recursive reference to a subpattern whose number was greater than 39
940 went wrong under certain circumstances in UTF-8 mode. This bug could also
941 have affected the operation of pcre_study().
942
943 25. Realized that a little bit of performance could be had by replacing
944 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
945
946 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
947
948 27. Possessive quantifiers such as a++ were previously implemented by turning
949 them into atomic groups such as ($>a+). Now they have their own opcodes,
950 which improves performance. This includes the automatically created ones
951 from 23 above.
952
953 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
954 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
955 the first matched character to be a colon. This applied both to named and
956 numbered groups.
957
958 29. The ucpinternal.h header file was missing its idempotency #ifdef.
959
960 30. I was sent a "project" file called libpcre.a.dev which I understand makes
961 building PCRE on Windows easier, so I have included it in the distribution.
962
963 31. There is now a check in pcretest against a ridiculously large number being
964 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
965 loop, the loop is abandoned.
966
967 32. Forward references to subpatterns in conditions such as (?(2)...) where
968 subpattern 2 is defined later cause pcre_compile() to search forwards in
969 the pattern for the relevant set of parentheses. This search went wrong
970 when there were unescaped parentheses in a character class, parentheses
971 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
972
973 33. "Subroutine" calls and backreferences were previously restricted to
974 referencing subpatterns earlier in the regex. This restriction has now
975 been removed.
976
977 34. Added a number of extra features that are going to be in Perl 5.10. On the
978 whole, these are just syntactic alternatives for features that PCRE had
979 previously implemented using the Python syntax or my own invention. The
980 other formats are all retained for compatibility.
981
982 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
983 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
984 also .NET compatible.
985
986 (b) A recursion or subroutine call to a named group can now be defined as
987 (?&name) as well as (?P>name).
988
989 (c) A backreference to a named group can now be defined as \k<name> or
990 \k'name' as well as (?P=name). The new forms, as well as being in Perl
991 5.10, are also .NET compatible.
992
993 (d) A conditional reference to a named group can now use the syntax
994 (?(<name>) or (?('name') as well as (?(name).
995
996 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
997 groups (named and numbered) that are never evaluated inline, but can be
998 called as "subroutines" from elsewhere. In effect, the DEFINE condition
999 is always false. There may be only one alternative in such a group.
1000
1001 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1002 as the simple (?(R). The condition is true only if the most recent
1003 recursion is that of the given number or name. It does not search out
1004 through the entire recursion stack.
1005
1006 (g) The escape \gN or \g{N} has been added, where N is a positive or
1007 negative number, specifying an absolute or relative reference.
1008
1009 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1010 some "unreachable code" warnings.
1011
1012 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1013 things, this adds five new scripts.
1014
1015 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1016 There were also incompatibilities regarding the handling of \Q..\E inside
1017 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1018 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1019
1020 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1021 matches an empty string, and forcibly breaks the loop. There were bugs in
1022 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1023 against aaaa the result was just "a" rather than "aaaa", for example. Two
1024 separate and independent bugs (that affected different cases) have been
1025 fixed.
1026
1027 39. Refactored the code to abolish the use of different opcodes for small
1028 capturing bracket numbers. This is a tidy that I avoided doing when I
1029 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1030 The new approach is not only tidier, it makes it possible to reduce the
1031 memory needed to fix the previous bug (38).
1032
1033 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1034 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1035 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1036 mode.
1037
1038 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1039 report.
1040
1041 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1042 copy construction and assignment in the C++ wrapper.
1043
1044 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1045 couple of bugs that could have given wrong results in the "--newline=crlf"
1046 case.
1047
1048 44. Added a number of casts and did some reorganization of signed/unsigned int
1049 variables following suggestions from Dair Grant. Also renamed the variable
1050 "this" as "item" because it is a C++ keyword.
1051
1052 45. Arranged for dftables to add
1053
1054 #include "pcre_internal.h"
1055
1056 to pcre_chartables.c because without it, gcc 4.x may remove the array
1057 definition from the final binary if PCRE is built into a static library and
1058 dead code stripping is activated.
1059
1060 46. For an unanchored pattern, if a match attempt fails at the start of a
1061 newline sequence, and the newline setting is CRLF or ANY, and the next two
1062 characters are CRLF, advance by two characters instead of one.
1063
1064
1065 Version 6.7 04-Jul-06
1066 ---------------------
1067
1068 1. In order to handle tests when input lines are enormously long, pcretest has
1069 been re-factored so that it automatically extends its buffers when
1070 necessary. The code is crude, but this _is_ just a test program. The
1071 default size has been increased from 32K to 50K.
1072
1073 2. The code in pcre_study() was using the value of the re argument before
1074 testing it for NULL. (Of course, in any sensible call of the function, it
1075 won't be NULL.)
1076
1077 3. The memmove() emulation function in pcre_internal.h, which is used on
1078 systems that lack both memmove() and bcopy() - that is, hardly ever -
1079 was missing a "static" storage class specifier.
1080
1081 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1082 containing an extended class (one that cannot be represented by a bitmap
1083 because it contains high-valued characters or Unicode property items, e.g.
1084 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1085 pattern, but PCRE should not loop if you do not (it no longer does).
1086 [Detail: two cases were found: (a) a repeated subpattern containing an
1087 extended class; (b) a recursive reference to a subpattern that followed a
1088 previous extended class. It wasn't skipping over the extended class
1089 correctly when UTF-8 mode was not set.]
1090
1091 5. A negated single-character class was not being recognized as fixed-length
1092 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1093 compile error "lookbehind assertion is not fixed length".
1094
1095 6. The RunPerlTest auxiliary script was showing an unexpected difference
1096 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1097 write a Perl script that can interpret lines of an input file either as
1098 byte characters or as UTF-8, which is what "perltest" was being required to
1099 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1100 can't do is switch easily at run time between having the "use utf8;" pragma
1101 or not. In the end, I fudged it by using the RunPerlTest script to insert
1102 "use utf8;" explicitly for the UTF-8 tests.
1103
1104 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1105 the end of the subject string, contrary to the documentation and to what
1106 Perl does. This was true of both matching functions. Now it matches only at
1107 the start of the subject and immediately after *internal* newlines.
1108
1109 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1110 a pointer to an int instead of a pointer to an unsigned long int. This
1111 caused problems on 64-bit systems.
1112
1113 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1114 instance of the 'standard' template library not being so standard".
1115
1116 10. There was no check on the number of named subpatterns nor the maximum
1117 length of a subpattern name. The product of these values is used to compute
1118 the size of the memory block for a compiled pattern. By supplying a very
1119 long subpattern name and a large number of named subpatterns, the size
1120 computation could be caused to overflow. This is now prevented by limiting
1121 the length of names to 32 characters, and the number of named subpatterns
1122 to 10,000.
1123
1124 11. Subpatterns that are repeated with specific counts have to be replicated in
1125 the compiled pattern. The size of memory for this was computed from the
1126 length of the subpattern and the repeat count. The latter is limited to
1127 65535, but there was no limit on the former, meaning that integer overflow
1128 could in principle occur. The compiled length of a repeated subpattern is
1129 now limited to 30,000 bytes in order to prevent this.
1130
1131 12. Added the optional facility to have named substrings with the same name.
1132
1133 13. Added the ability to use a named substring as a condition, using the
1134 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1135 are numbers (not recommended). Forward references are permitted.
1136
1137 14. Added forward references in named backreferences (if you see what I mean).
1138
1139 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1140 pattern could run off the end of the subject. For example, the pattern
1141 "(?s)(.{1,5})"8 did this with the subject "ab".
1142
1143 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1144 PCRE_CASELESS was set when matching characters that were quantified with ?
1145 or *.
1146
1147 17. A character class other than a single negated character that had a minimum
1148 but no maximum quantifier - for example [ab]{6,} - was not handled
1149 correctly by pce_dfa_exec(). It would match only one character.
1150
1151 18. A valid (though odd) pattern that looked like a POSIX character
1152 class but used an invalid character after [ (for example [[,abc,]]) caused
1153 pcre_compile() to give the error "Failed: internal error: code overflow" or
1154 in some cases to crash with a glibc free() error. This could even happen if
1155 the pattern terminated after [[ but there just happened to be a sequence of
1156 letters, a binary zero, and a closing ] in the memory that followed.
1157
1158 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1159 over the years. Originally (before any Unicode support), just the bottom 8
1160 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1161 output from "man perlunicode" includes this:
1162
1163 The regular expression compiler produces polymorphic opcodes. That
1164 is, the pattern adapts to the data and automatically switches to
1165 the Unicode character scheme when presented with Unicode data--or
1166 instead uses a traditional byte scheme when presented with byte
1167 data.
1168
1169 Sadly, a wide octal escape does not cause a switch, and in a string with
1170 no other multibyte characters, these octal escapes are treated as before.
1171 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1172 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1173 Unicode string.
1174
1175 I have not perpetrated such confusion in PCRE. Up till now, it took just
1176 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1177 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1178 translate to the appropriate multibyte character.
1179
1180 29. Applied some refactoring to reduce the number of warnings from Microsoft
1181 and Borland compilers. This has included removing the fudge introduced
1182 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1183 a warning about an unused variable.
1184
1185 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1186 characters since release 4.0, because Perl (from release 5.004) does not.
1187 [Or at least, is documented not to: some releases seem to be in conflict
1188 with the documentation.] However, when a pattern was studied with
1189 pcre_study() and all its branches started with \s, PCRE still included VT
1190 as a possible starting character. Of course, this did no harm; it just
1191 caused an unnecessary match attempt.
1192
1193 22. Removed a now-redundant internal flag bit that recorded the fact that case
1194 dependency changed within the pattern. This was once needed for "required
1195 byte" processing, but is no longer used. This recovers a now-scarce options
1196 bit. Also moved the least significant internal flag bit to the most-
1197 significant bit of the word, which was not previously used (hangover from
1198 the days when it was an int rather than a uint) to free up another bit for
1199 the future.
1200
1201 23. Added support for CRLF line endings as well as CR and LF. As well as the
1202 default being selectable at build time, it can now be changed at runtime
1203 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1204 specify that it is scanning data with non-default line endings.
1205
1206 24. Changed the definition of CXXLINK to make it agree with the definition of
1207 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1208
1209 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1210 recursions. This makes a big different to stack usage for some patterns.
1211
1212 26. If a subpattern containing a named recursion or subroutine reference such
1213 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1214 the space required for the compiled pattern went wrong and gave too small a
1215 value. Depending on the environment, this could lead to "Failed: internal
1216 error: code overflow at offset 49" or "glibc detected double free or
1217 corruption" errors.
1218
1219 27. Applied patches from Google (a) to support the new newline modes and (b) to
1220 advance over multibyte UTF-8 characters in GlobalReplace.
1221
1222 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1223 difference for some implementation of PCRE in some Windows version.
1224
1225 29. Added some extra testing facilities to pcretest:
1226
1227 \q<number> in a data line sets the "match limit" value
1228 \Q<number> in a data line sets the "match recursion limt" value
1229 -S <number> sets the stack size, where <number> is in megabytes
1230
1231 The -S option isn't available for Windows.
1232
1233
1234 Version 6.6 06-Feb-06
1235 ---------------------
1236
1237 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1238 in pcreposix.h. I have copied the definition from pcre.h.
1239
1240 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1241 because pcre.h is no longer a built file.
1242
1243 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1244 not normally included in the compiled code.
1245
1246
1247 Version 6.5 01-Feb-06
1248 ---------------------
1249
1250 1. When using the partial match feature with pcre_dfa_exec(), it was not
1251 anchoring the second and subsequent partial matches at the new starting
1252 point. This could lead to incorrect results. For example, with the pattern
1253 /1234/, partially matching against "123" and then "a4" gave a match.
1254
1255 2. Changes to pcregrep:
1256
1257 (a) All non-match returns from pcre_exec() were being treated as failures
1258 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1259 error message is output. Some extra information is given for the
1260 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1261 probably the only errors that are likely to be caused by users (by
1262 specifying a regex that has nested indefinite repeats, for instance).
1263 If there are more than 20 of these errors, pcregrep is abandoned.
1264
1265 (b) A binary zero was treated as data while matching, but terminated the
1266 output line if it was written out. This has been fixed: binary zeroes
1267 are now no different to any other data bytes.
1268
1269 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1270 used to set a locale for matching. The --locale=xxxx long option has
1271 been added (no short equivalent) to specify a locale explicitly on the
1272 pcregrep command, overriding the environment variables.
1273
1274 (d) When -B was used with -n, some line numbers in the output were one less
1275 than they should have been.
1276
1277 (e) Added the -o (--only-matching) option.
1278
1279 (f) If -A or -C was used with -c (count only), some lines of context were
1280 accidentally printed for the final match.
1281
1282 (g) Added the -H (--with-filename) option.
1283
1284 (h) The combination of options -rh failed to suppress file names for files
1285 that were found from directory arguments.
1286
1287 (i) Added the -D (--devices) and -d (--directories) options.
1288
1289 (j) Added the -F (--fixed-strings) option.
1290
1291 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1292
1293 (l) Added the --colo(u)r option.
1294
1295 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1296 is not present by default.
1297
1298 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1299 items such as (?R) or (?1), when the recursion could match a number of
1300 alternatives. If it matched one of the alternatives, but subsequently,
1301 outside the recursion, there was a failure, the code tried to back up into
1302 the recursion. However, because of the way PCRE is implemented, this is not
1303 possible, and the result was an incorrect result from the match.
1304
1305 In order to prevent this happening, the specification of recursion has
1306 been changed so that all such subpatterns are automatically treated as
1307 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1308
1309 4. I had overlooked the fact that, in some locales, there are characters for
1310 which isalpha() is true but neither isupper() nor islower() are true. In
1311 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1312 and ordfeminine) are like this. This affected the treatment of \w and \W
1313 when they appeared in character classes, but not when they appeared outside
1314 a character class. The bit map for "word" characters is now created
1315 separately from the results of isalnum() instead of just taking it from the
1316 upper, lower, and digit maps. (Plus the underscore character, of course.)
1317
1318 5. The above bug also affected the handling of POSIX character classes such as
1319 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1320 permanent tables. Instead, the bit maps for such a class were previously
1321 created as the appropriate unions of the upper, lower, and digit bitmaps.
1322 Now they are created by subtraction from the [[:word:]] class, which has
1323 its own bitmap.
1324
1325 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1326 It is created by subtracting the vertical space characters (\x09, \x0a,
1327 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1328 subtraction was done in the overall bitmap for a character class, meaning
1329 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1330 be recognized. This bug has been fixed.
1331
1332 7. Patches from the folks at Google:
1333
1334 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1335 real life, but is still worth protecting against".
1336
1337 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1338 regular expressions".
1339
1340 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1341 have it.
1342
1343 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1344 "configure" and the latter not, in order to fix a problem somebody had
1345 with compiling the Arg class on HP-UX.
1346
1347 (e) Improve the error-handling of the C++ wrapper a little bit.
1348
1349 (f) New tests for checking recursion limiting.
1350
1351 8. The pcre_memmove() function, which is used only if the environment does not
1352 have a standard memmove() function (and is therefore rarely compiled),
1353 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1354 returning a result (though PCRE never actually uses the result).
1355
1356 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1357 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1358 returned instead of calling malloc() with an overflowing number that would
1359 most likely cause subsequent chaos.
1360
1361 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1362
1363 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1364 with this option is matched, the nmatch and pmatch options of regexec() are
1365 ignored.
1366
1367 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1368 provided in case anyone wants to the the POSIX interface with UTF-8
1369 strings.
1370
1371 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1372 C++ linking (needed for some HP-UX environments).
1373
1374 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1375 (unused parameter) and in the pcre_printint() function (omitted "default"
1376 switch label when the default is to do nothing).
1377
1378 15. Added some code to make it possible, when PCRE is compiled as a C++
1379 library, to replace subject pointers for pcre_exec() with a smart pointer
1380 class, thus making it possible to process discontinuous strings.
1381
1382 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1383 much the same function. They were added by different people who were trying
1384 to make PCRE easy to compile on non-Unix systems. It has been suggested
1385 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1386 for compiling on Windows systems. I have therefore replaced it with
1387 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1388 defaults to "extern" for C or "extern C" for C++, which works fine on
1389 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1390 SCOPE with something explicit in config.h. In addition:
1391
1392 (a) pcreposix.h still had just "extern" instead of either of these macros;
1393 I have replaced it with PCRE_DATA_SCOPE.
1394
1395 (b) Functions such as _pcre_xclass(), which are internal to the library,
1396 but external in the C sense, all had PCRE_EXPORT in their definitions.
1397 This is apparently wrong for the Windows case, so I have removed it.
1398 (It makes no difference on Unix-like systems.)
1399
1400 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1401 of recursive calls to match(). This is different to MATCH_LIMIT because
1402 that limits the total number of calls to match(), not all of which increase
1403 the depth of recursion. Limiting the recursion depth limits the amount of
1404 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1405 when PCRE is compiled, and changed at run time. A patch from Google adds
1406 this functionality to the C++ interface.
1407
1408 18. Changes to the handling of Unicode character properties:
1409
1410 (a) Updated the table to Unicode 4.1.0.
1411
1412 (b) Recognize characters that are not in the table as "Cn" (undefined).
1413
1414 (c) I revised the way the table is implemented to a much improved format
1415 which includes recognition of ranges. It now supports the ranges that
1416 are defined in UnicodeData.txt, and it also amalgamates other
1417 characters into ranges. This has reduced the number of entries in the
1418 table from around 16,000 to around 3,000, thus reducing its size
1419 considerably. I realized I did not need to use a tree structure after
1420 all - a binary chop search is just as efficient. Having reduced the
1421 number of entries, I extended their size from 6 bytes to 8 bytes to
1422 allow for more data.
1423
1424 (d) Added support for Unicode script names via properties such as \p{Han}.
1425
1426 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1427 matching that character.
1428
1429 20. When matching a repeated Unicode property with a minimum greater than zero,
1430 (for example \pL{2,}), PCRE could look past the end of the subject if it
1431 reached it while seeking the minimum number of characters. This could
1432 happen only if some of the characters were more than one byte long, because
1433 there is a check for at least the minimum number of bytes.
1434
1435 21. Refactored the implementation of \p and \P so as to be more general, to
1436 allow for more different types of property in future. This has changed the
1437 compiled form incompatibly. Anybody with saved compiled patterns that use
1438 \p or \P will have to recompile them.
1439
1440 22. Added "Any" and "L&" to the supported property types.
1441
1442 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1443 but give a compile time error if the value is greater than 0xff.
1444
1445 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1446 accidentally not being installed or uninstalled.
1447
1448 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1449 made were to insert the current release number. This seemed silly, because
1450 it made things harder for people building PCRE on systems that don't run
1451 "configure". I have turned pcre.h into a distributed file, no longer built
1452 by "configure", with the version identification directly included. There is
1453 no longer a pcre.h.in file.
1454
1455 However, this change necessitated a change to the pcre-config script as
1456 well. It is built from pcre-config.in, and one of the substitutions was the
1457 release number. I have updated configure.ac so that ./configure now finds
1458 the release number by grepping pcre.h.
1459
1460 26. Added the ability to run the tests under valgrind.
1461
1462
1463 Version 6.4 05-Sep-05
1464 ---------------------
1465
1466 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1467 "--" to be printed when multiple files were scanned, even when none of the
1468 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1469 consider it to be a bug, and have restored the previous behaviour.
1470
1471 2. A couple of code tidies to get rid of compiler warnings.
1472
1473 3. The pcretest program used to cheat by referring to symbols in the library
1474 whose names begin with _pcre_. These are internal symbols that are not
1475 really supposed to be visible externally, and in some environments it is
1476 possible to suppress them. The cheating is now confined to including
1477 certain files from the library's source, which is a bit cleaner.
1478
1479 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1480 file's purpose clearer.
1481
1482 5. Reorganized pcre_ucp_findchar().
1483
1484
1485 Version 6.3 15-Aug-05
1486 ---------------------
1487
1488 1. The file libpcre.pc.in did not have general read permission in the tarball.
1489
1490 2. There were some problems when building without C++ support:
1491
1492 (a) If C++ support was not built, "make install" and "make test" still
1493 tried to test it.
1494
1495 (b) There were problems when the value of CXX was explicitly set. Some
1496 changes have been made to try to fix these, and ...
1497
1498 (c) --disable-cpp can now be used to explicitly disable C++ support.
1499
1500 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1501 backslash in a target when C++ was disabled. This confuses some
1502 versions of "make", apparently. Using an intermediate variable solves
1503 this. (Same for CPP_LOBJ.)
1504
1505 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1506 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1507 necessary on certain architectures.
1508
1509 4. Added a setting of -export-symbols-regex to the link command to remove
1510 those symbols that are exported in the C sense, but actually are local
1511 within the library, and not documented. Their names all begin with
1512 "_pcre_". This is not a perfect job, because (a) we have to except some
1513 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1514 available (and never for static libraries). I have made a note to try to
1515 find a way round (a) in the future.
1516
1517
1518 Version 6.2 01-Aug-05
1519 ---------------------
1520
1521 1. There was no test for integer overflow of quantifier values. A construction
1522 such as {1111111111111111} would give undefined results. What is worse, if
1523 a minimum quantifier for a parenthesized subpattern overflowed and became
1524 negative, the calculation of the memory size went wrong. This could have
1525 led to memory overwriting.
1526
1527 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1528
1529 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1530 operating environments where this matters.
1531
1532 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1533 PCRE options from within the C++ wrapper.
1534
1535 5. Named capturing subpatterns were not being correctly counted when a pattern
1536 was compiled. This caused two problems: (a) If there were more than 100
1537 such subpatterns, the calculation of the memory needed for the whole
1538 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1539 back references of the form \12, where the number was greater than 9, were
1540 not recognized as back references, even though there were sufficient
1541 previous subpatterns.
1542
1543 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1544 versions of gcc, e.g. 2.95.4.
1545
1546
1547 Version 6.1 21-Jun-05
1548 ---------------------
1549
1550 1. There was one reference to the variable "posix" in pcretest.c that was not
1551 surrounded by "#if !defined NOPOSIX".
1552
1553 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1554 the cross-check on the old pcre_info() function, for the benefit of the
1555 cut-down version of PCRE that is currently imported into Exim.
1556
1557 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1558 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1559 patterns that start (?i) but I don't think that matters. The use of (?i) is
1560 just an example; this all applies to the other options as well.
1561
1562 4. Since libtool seems to echo the compile commands it is issuing, the output
1563 from "make" can be reduced a bit by putting "@" in front of each libtool
1564 compile command.
1565
1566 5. Patch from the folks at Google for configure.in to be a bit more thorough
1567 in checking for a suitable C++ installation before trying to compile the
1568 C++ stuff. This should fix a reported problem when a compiler was present,
1569 but no suitable headers.
1570
1571 6. The man pages all had just "PCRE" as their title. I have changed them to
1572 be the relevant file name. I have also arranged that these names are
1573 retained in the file doc/pcre.txt, which is a concatenation in text format
1574 of all the man pages except the little individual ones for each function.
1575
1576 7. The NON-UNIX-USE file had not been updated for the different set of source
1577 files that come with release 6. I also added a few comments about the C++
1578 wrapper.
1579
1580
1581 Version 6.0 07-Jun-05
1582 ---------------------
1583
1584 1. Some minor internal re-organization to help with my DFA experiments.
1585
1586 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1587 didn't matter for the library itself when fully configured, but did matter
1588 when compiling without UCP support, or within Exim, where the ucp files are
1589 not imported.
1590
1591 3. Refactoring of the library code to split up the various functions into
1592 different source modules. The addition of the new DFA matching code (see
1593 below) to a single monolithic source would have made it really too
1594 unwieldy, quite apart from causing all the code to be include in a
1595 statically linked application, when only some functions are used. This is
1596 relevant even without the DFA addition now that patterns can be compiled in
1597 one application and matched in another.
1598
1599 The downside of splitting up is that there have to be some external
1600 functions and data tables that are used internally in different modules of
1601 the library but which are not part of the API. These have all had their
1602 names changed to start with "_pcre_" so that they are unlikely to clash
1603 with other external names.
1604
1605 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1606 a different (DFA) algorithm. Although it is slower than the original
1607 function, it does have some advantages for certain types of matching
1608 problem.
1609
1610 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1611 including restarting after a partial match.
1612
1613 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1614 defined when compiling for Windows was sent to me. I have put it into the
1615 code, though I have no means of testing or verifying it.
1616
1617 7. Added the pcre_refcount() auxiliary function.
1618
1619 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1620 match before or at the first newline in the subject string. In pcretest,
1621 the /f option on a pattern can be used to set this.
1622
1623 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1624 would behave wrongly. This has been present in PCRE since release 4.0.
1625
1626 10. A number of changes to the pcregrep command:
1627
1628 (a) Refactored how -x works; insert ^(...)$ instead of setting
1629 PCRE_ANCHORED and checking the length, in preparation for adding
1630 something similar for -w.
1631
1632 (b) Added the -w (match as a word) option.
1633
1634 (c) Refactored the way lines are read and buffered so as to have more
1635 than one at a time available.
1636
1637 (d) Implemented a pcregrep test script.
1638
1639 (e) Added the -M (multiline match) option. This allows patterns to match
1640 over several lines of the subject. The buffering ensures that at least
1641 8K, or the rest of the document (whichever is the shorter) is available
1642 for matching (and similarly the previous 8K for lookbehind assertions).
1643
1644 (f) Changed the --help output so that it now says
1645
1646 -w, --word-regex(p)
1647
1648 instead of two lines, one with "regex" and the other with "regexp"
1649 because that confused at least one person since the short forms are the
1650 same. (This required a bit of code, as the output is generated
1651 automatically from a table. It wasn't just a text change.)
1652
1653 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1654 option but starts with a hyphen. Could be a pattern or a path name
1655 starting with a hyphen, for instance.
1656
1657 (h) "-" can be given as a file name to represent stdin.
1658
1659 (i) When file names are being printed, "(standard input)" is used for
1660 the standard input, for compatibility with GNU grep. Previously
1661 "<stdin>" was used.
1662
1663 (j) The option --label=xxx can be used to supply a name to be used for
1664 stdin when file names are being printed. There is no short form.
1665
1666 (k) Re-factored the options decoding logic because we are going to add
1667 two more options that take data. Such options can now be given in four
1668 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1669
1670 (l) Added the -A, -B, and -C options for requesting that lines of context
1671 around matches be printed.
1672
1673 (m) Added the -L option to print the names of files that do not contain
1674 any matching lines, that is, the complement of -l.
1675
1676 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1677 continue to scan other files.
1678
1679 (o) The -s option was incorrectly implemented. For compatibility with other
1680 greps, it now suppresses the error message for a non-existent or non-
1681 accessible file (but not the return code). There is a new option called
1682 -q that suppresses the output of matching lines, which was what -s was
1683 previously doing.
1684
1685 (p) Added --include and --exclude options to specify files for inclusion
1686 and exclusion when recursing.
1687
1688 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1689 Hopefully, it now does.
1690
1691 12. Missing cast in pcre_study().
1692
1693 13. Added an "uninstall" target to the makefile.
1694
1695 14. Replaced "extern" in the function prototypes in Makefile.in with
1696 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1697 world, but is set differently for Windows.
1698
1699 15. Added a second compiling function called pcre_compile2(). The only
1700 difference is that it has an extra argument, which is a pointer to an
1701 integer error code. When there is a compile-time failure, this is set
1702 non-zero, in addition to the error test pointer being set to point to an
1703 error message. The new argument may be NULL if no error number is required
1704 (but then you may as well call pcre_compile(), which is now just a
1705 wrapper). This facility is provided because some applications need a
1706 numeric error indication, but it has also enabled me to tidy up the way
1707 compile-time errors are handled in the POSIX wrapper.
1708
1709 16. Added VPATH=.libs to the makefile; this should help when building with one
1710 prefix path and installing with another. (Or so I'm told by someone who
1711 knows more about this stuff than I do.)
1712
1713 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1714 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1715 match everything, including newlines. This is not POSIX-compatible, but
1716 somebody wanted the feature. From pcretest it can be activated by using
1717 both the P and the s flags.
1718
1719 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1720
1721 19. libpcre.pc was being incorrectly installed as executable.
1722
1723 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1724 it now also looks for '\r' so that it will work unmodified on Windows.
1725
1726 21. Added Google's contributed C++ wrapper to the distribution.
1727
1728 22. Added some untidy missing memory free() calls in pcretest, to keep
1729 Electric Fence happy when testing.
1730
1731
1732
1733 Version 5.0 13-Sep-04
1734 ---------------------
1735
1736 1. Internal change: literal characters are no longer packed up into items
1737 containing multiple characters in a single byte-string. Each character
1738 is now matched using a separate opcode. However, there may be more than one
1739 byte in the character in UTF-8 mode.
1740
1741 2. The pcre_callout_block structure has two new fields: pattern_position and
1742 next_item_length. These contain the offset in the pattern to the next match
1743 item, and its length, respectively.
1744
1745 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1746 insertion of callouts before each pattern item. Added the /C option to
1747 pcretest to make use of this.
1748
1749 4. On the advice of a Windows user, the lines
1750
1751 #if defined(_WIN32) || defined(WIN32)
1752 _setmode( _fileno( stdout ), 0x8000 );
1753 #endif /* defined(_WIN32) || defined(WIN32) */
1754
1755 have been added to the source of pcretest. This apparently does useful
1756 magic in relation to line terminators.
1757
1758 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1759 for the benefit of those environments where the "b" makes a difference.
1760
1761 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1762 to know about it. I have put a hack into configure.in that adds in code
1763 to set GCC=yes if CC=icc. This seems to end up at a point in the
1764 generated configure script that is early enough to affect the setting of
1765 compiler options, which is what is needed, but I have no means of testing
1766 whether it really works. (The user who reported this had patched the
1767 generated configure script, which of course I cannot do.)
1768
1769 LATER: After change 22 below (new libtool files), the configure script
1770 seems to know about icc (and also ecc). Therefore, I have commented out
1771 this hack in configure.in.
1772
1773 7. Added support for pkg-config (2 patches were sent in).
1774
1775 8. Negated POSIX character classes that used a combination of internal tables
1776 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1777 [[:^ascii]]. Typically, they would match almost any characters. The other
1778 POSIX classes were not broken in this way.
1779
1780 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1781 to find the match, as PCRE was deluded into thinking that the match had to
1782 start at the start point or following a newline. The same bug applied to
1783 patterns with negative forward assertions or any backward assertions
1784 preceding ".*" at the start, unless the pattern required a fixed first
1785 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1786
1787 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1788 starting at the last subject character, bytes beyond the end of the subject
1789 string were read.
1790
1791 11. Renamed the variable "class" as "classbits" to make life easier for C++
1792 users. (Previously there was a macro definition, but it apparently wasn't
1793 enough.)
1794
1795 12. Added the new field "tables" to the extra data so that tables can be passed
1796 in at exec time, or the internal tables can be re-selected. This allows
1797 a compiled regex to be saved and re-used at a later time by a different
1798 program that might have everything at different addresses.
1799
1800 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1801 -R library as well as a -L library.
1802
1803 14. The debugging options of pcretest (-d on the command line or D on a
1804 pattern) showed incorrect output for anything following an extended class
1805 that contained multibyte characters and which was followed by a quantifier.
1806
1807 15. Added optional support for general category Unicode character properties
1808 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1809 support. It adds about 90K to the size of the library. The meanings of the
1810 inbuilt class escapes such as \d and \s have NOT been changed.
1811
1812 16. Updated pcredemo.c to include calls to free() to release the memory for the
1813 compiled pattern.
1814
1815 17. The generated file chartables.c was being created in the source directory
1816 instead of in the building directory. This caused the build to fail if the
1817 source directory was different from the building directory, and was
1818 read-only.
1819
1820 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1821 file. No doubt somebody will tell me if they don't make sense... Also added
1822 Dan Mooney's comments about building on OpenVMS.
1823
1824 19. Added support for partial matching via the PCRE_PARTIAL option for
1825 pcre_exec() and the \P data escape in pcretest.
1826
1827 20. Extended pcretest with 3 new pattern features:
1828
1829 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1830 write the compiled pattern to the file whose name is "rest-of-line".
1831 This is a straight binary dump of the data, with the saved pointer to
1832 the character tables forced to be NULL. The study data, if any, is
1833 written too. After writing, pcretest reads a new pattern.
1834
1835 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1836 compiled pattern from the given file. There must not be any
1837 occurrences of "<" in the file name (pretty unlikely); if there are,
1838 pcretest will instead treat the initial "<" as a pattern delimiter.
1839 After reading in the pattern, pcretest goes on to read data lines as
1840 usual.
1841
1842 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1843 and 16-bit fields in a compiled pattern, to simulate a pattern that
1844 was compiled on a host of opposite endianness.
1845
1846 21. The pcre-exec() function can now cope with patterns that were compiled on
1847 hosts of opposite endianness, with this restriction:
1848
1849 As for any compiled expression that is saved and used later, the tables
1850 pointer field cannot be preserved; the extra_data field in the arguments
1851 to pcre_exec() should be used to pass in a tables address if a value
1852 other than the default internal tables were used at compile time.
1853
1854 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1855 now diagnosed as an error. Previously, most of the time, a negative number
1856 would have been treated as zero, but if in addition "ovector" was passed as
1857 NULL, a crash could occur.
1858
1859 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1860 new versions from the libtool 1.5 distribution (the last one is a copy of
1861 a file called libtool.m4). This seems to have fixed the need to patch
1862 "configure" to support Darwin 1.3 (which I used to do). However, I still
1863 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1864 workstation).
1865
1866 24. Changed the PCRE licence to be the more standard "BSD" licence.
1867
1868
1869 Version 4.5 01-Dec-03
1870 ---------------------
1871
1872 1. There has been some re-arrangement of the code for the match() function so
1873 that it can be compiled in a version that does not call itself recursively.
1874 Instead, it keeps those local variables that need separate instances for
1875 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1876 needs to "recurse". Keeping track of where control must go is done by means
1877 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1878 hide most of the details from the main code, and operates only if
1879 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1880 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1881 operating.
1882
1883 To make it easier for callers to provide specially tailored get/free
1884 functions for this usage, two new functions, pcre_stack_malloc, and
1885 pcre_stack_free, are used. They are always called in strict stacking order,
1886 and the size of block requested is always the same.
1887
1888 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1889 PCRE has been compiled to use the stack or the heap for recursion. The
1890 -C option of pcretest uses this to show which version is compiled.
1891
1892 A new data escape \S, is added to pcretest; it causes the amounts of store
1893 obtained and freed by both kinds of malloc/free at match time to be added
1894 to the output.
1895
1896 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1897 what's available on my current Linux desktop machine.
1898
1899 3. When matching a UTF-8 string, the test for a valid string at the start has
1900 been extended. If start_offset is not zero, PCRE now checks that it points
1901 to a byte that is the start of a UTF-8 character. If not, it returns
1902 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1903 this is necessary because there may be backward assertions in the pattern.
1904 When matching the same subject several times, it may save resources to use
1905 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1906
1907 4. The code for checking the validity of UTF-8 strings has been tightened so
1908 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1909 containing "overlong sequences".
1910
1911 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1912 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1913 should have been "&", but it just so happened that all the cases this let
1914 through by mistake were picked up later in the function.
1915
1916 6. I had used a variable called "isblank" - this is a C99 function, causing
1917 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1918
1919 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1920 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1921 so the version is shown; (c) stop "make test" echoing "./RunTest".
1922
1923 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1924
1925 9. The prototype for memmove() for systems that don't have it was using
1926 size_t, but the inclusion of the header that defines size_t was later. I've
1927 moved the #includes for the C headers earlier to avoid this.
1928
1929 10. Added some adjustments to the code to make it easier to compiler on certain
1930 special systems:
1931
1932 (a) Some "const" qualifiers were missing.
1933 (b) Added the macro EXPORT before all exported functions; by default this
1934 is defined to be empty.
1935 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1936 that it reads its output file name as an argument instead of writing
1937 to the standard output and assuming this can be redirected.
1938
1939 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1940 class containing characters with values greater than 255, PCRE compilation
1941 went into a loop.
1942
1943 12. A recursive reference to a subpattern that was within another subpattern
1944 that had a minimum quantifier of zero caused PCRE to crash. For example,
1945 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1946 recursion. If the recursively-called subpattern itself had a zero repeat,
1947 that was OK.
1948
1949 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1950 buffer into which it was copied (for escape processing) was still set at
1951 1024, so long lines caused crashes.
1952
1953 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1954 "internal error: code overflow...". This applied to any character class
1955 that was followed by a possessive quantifier.
1956
1957 15. Modified the Makefile to add libpcre.la as a prerequisite for
1958 libpcreposix.la because I was told this is needed for a parallel build to
1959 work.
1960
1961 16. If a pattern that contained .* following optional items at the start was
1962 studied, the wrong optimizing data was generated, leading to matching
1963 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1964 matching string must start with a or b or c. The correct conclusion for
1965 this pattern is that a match can start with any character.
1966
1967
1968 Version 4.4 13-Aug-03
1969 ---------------------
1970
1971 1. In UTF-8 mode, a character class containing characters with values between
1972 127 and 255 was not handled correctly if the compiled pattern was studied.
1973 In fixing this, I have also improved the studying algorithm for such
1974 classes (slightly).
1975
1976 2. Three internal functions had redundant arguments passed to them. Removal
1977 might give a very teeny performance improvement.
1978
1979 3. Documentation bug: the value of the capture_top field in a callout is *one
1980 more than* the number of the hightest numbered captured substring.
1981
1982 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1983 in incorrectly linking with a previously installed version. They now link
1984 explicitly with libpcre.la.
1985
1986 5. configure.in no longer needs to recognize Cygwin specially.
1987
1988 6. A problem in pcre.in for Windows platforms is fixed.
1989
1990 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1991 pcretest, it used to include the size of the study block as part of its
1992 output. Unfortunately, the structure contains a field that has a different
1993 size on different hardware architectures. This meant that the tests that
1994 showed this size failed. As the block is currently always of a fixed size,
1995 this information isn't actually particularly useful in pcretest output, so
1996 I have just removed it.
1997
1998 8. Three pre-processor statements accidentally did not start in column 1.
1999 Sadly, there are *still* compilers around that complain, even though
2000 standard C has not required this for well over a decade. Sigh.
2001
2002 9. In pcretest, the code for checking callouts passed small integers in the
2003 callout_data field, which is a void * field. However, some picky compilers
2004 complained about the casts involved for this on 64-bit systems. Now
2005 pcretest passes the address of the small integer instead, which should get
2006 rid of the warnings.
2007
2008 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2009 both compile and run time, and gives an error if an invalid UTF-8 sequence
2010 is found. There is a option for disabling this check in cases where the
2011 string is known to be correct and/or the maximum performance is wanted.
2012
2013 11. In response to a bug report, I changed one line in Makefile.in from
2014
2015 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2016 to
2017 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2018
2019 to look similar to other lines, but I have no way of telling whether this
2020 is the right thing to do, as I do not use Windows. No doubt I'll get told
2021 if it's wrong...
2022
2023
2024 Version 4.3 21-May-03
2025 ---------------------
2026
2027 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2028 Makefile.
2029
2030 2. Some refactoring to improve the quality of the code:
2031
2032 (i) The utf8_table... variables are now declared "const".
2033
2034 (ii) The code for \cx, which used the "case flipping" table to upper case
2035 lower case letters, now just substracts 32. This is ASCII-specific,
2036 but the whole concept of \cx is ASCII-specific, so it seems
2037 reasonable.
2038
2039 (iii) PCRE was using its character types table to recognize decimal and
2040 hexadecimal digits in the pattern. This is silly, because it handles
2041 only 0-9, a-f, and A-F, but the character types table is locale-
2042 specific, which means strange things might happen. A private
2043 table is now used for this - though it costs 256 bytes, a table is
2044 much faster than multiple explicit tests. Of course, the standard
2045 character types table is still used for matching digits in subject
2046 strings against \d.
2047
2048 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2049 ending in _t are). So I've renamed it as ESC_tee.
2050
2051 3. The first argument for regexec() in the POSIX wrapper should have been
2052 defined as "const".
2053
2054 4. Changed pcretest to use malloc() for its buffers so that they can be
2055 Electric Fenced for debugging.
2056
2057 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2058 to read one or more bytes before the start of the subject string. Often this
2059 had no effect on PCRE's behaviour, but in some circumstances it could
2060 provoke a segmentation fault.
2061
2062 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2063 to try to read one or more bytes before the start of the subject string.
2064
2065 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2066 UTF-8 support could misbehave in various ways if the subject string
2067 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2068 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2069 back over UTF-8 characters.)
2070
2071
2072 Version 4.2 14-Apr-03
2073 ---------------------
2074
2075 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2076
2077 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2078 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2079 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2080 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2081 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2082 and BUILD_EXEEXT
2083 Note: automatic setting of the BUILD variables is not yet working
2084 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2085 compile-time but not at link-time
2086 [LINK]: use for linking executables only
2087 make different versions for Windows and non-Windows
2088 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2089 libraries
2090 [LINK_FOR_BUILD]: new variable
2091 [OBJEXT]: use throughout
2092 [EXEEXT]: use throughout
2093 <winshared>: new target
2094 <wininstall>: new target
2095 <dftables.o>: use native compiler
2096 <dftables>: use native linker
2097 <install>: handle Windows platform correctly
2098 <clean>: ditto
2099 <check>: ditto
2100 copy DLL to top builddir before testing
2101
2102 As part of these changes, -no-undefined was removed again. This was reported
2103 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2104 in any case.
2105
2106 3. Some tidies to get rid of compiler warnings:
2107
2108 . In the match_data structure, match_limit was an unsigned long int, whereas
2109 match_call_count was an int. I've made them both unsigned long ints.
2110
2111 . In pcretest the fact that a const uschar * doesn't automatically cast to
2112 a void * provoked a warning.
2113
2114 . Turning on some more compiler warnings threw up some "shadow" variables
2115 and a few more missing casts.
2116
2117 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2118 option, a class that contained a single character with a value between 128
2119 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2120
2121 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2122 option, a class that contained several characters, but with at least one
2123 whose value was between 128 and 255 caused PCRE to crash.
2124
2125
2126 Version 4.1 12-Mar-03
2127 ---------------------
2128
2129 1. Compiling with gcc -pedantic found a couple of places where casts were
2130 needed, and a string in dftables.c that was longer than standard compilers are
2131 required to support.
2132
2133 2. Compiling with Sun's compiler found a few more places where the code could
2134 be tidied up in order to avoid warnings.
2135
2136 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2137 first of these names is deprecated in the latest Autoconf in favour of the name
2138 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2139 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2140 analogy I have changed it to CFLAGS_FOR_BUILD.
2141
2142 4. Added -no-undefined to the linking command in the Makefile, because this is
2143 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2144 linking step for the pcreposix library.
2145
2146 5. PCRE was failing to diagnose the case of two named groups with the same
2147 name.
2148
2149 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2150 literal character that is needed in the subject for a match, and scans along to
2151 ensure that it is present before embarking on the full matching process. This
2152 saves time in cases of nested unlimited repeats that are never going to match.
2153 Problem: the scan can take a lot of time if the subject is very long (e.g.
2154 megabytes), thus penalizing straightforward matches. It is now done only if the
2155 amount of subject to be scanned is less than 1000 bytes.
2156
2157 7. A lesser problem with the same optimization is that it was recording the
2158 first character of an anchored pattern as "needed", thus provoking a search
2159 right along the subject, even when the first match of the pattern was going to
2160 fail. The "needed" character is now not set for anchored patterns, unless it
2161 follows something in the pattern that is of non-fixed length. Thus, it still
2162 fulfils its original purpose of finding quick non-matches in cases of nested
2163 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2164
2165
2166 Version 4.0 17-Feb-03
2167 ---------------------
2168
2169 1. If a comment in an extended regex that started immediately after a meta-item
2170 extended to the end of string, PCRE compiled incorrect data. This could lead to
2171 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2172
2173 2. Moved to autoconf 2.53 and libtool 1.4.2.
2174
2175 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2176 the special perltest8 script is no longer needed - all the tests can be run
2177 from a single perltest script.
2178
2179 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2180 by \s. It has now been removed in PCRE. This means it isn't recognized as
2181 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2182 class [:space:] *does* include VT, thereby creating a mess.
2183
2184 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2185 space and tab.
2186
2187 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2188 its new features into the main test script, reducing the number of scripts.
2189
2190 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2191 were backward compatible, and made the (?i) apply to the whole pattern, as if
2192 /i were given. Now it behaves more logically, and applies the option setting
2193 only to what follows. PCRE has been changed to follow suit. However, if it
2194 finds options settings right at the start of the pattern, it extracts them into
2195 the global options, as before. Thus, they show up in the info data.
2196
2197 8. Added support for the \Q...\E escape sequence. Characters in between are
2198 treated as literals. This is slightly different from Perl in that $ and @ are
2199 also handled as literals inside the quotes. In Perl, they will cause variable
2200 interpolation. Note the following examples:
2201
2202 Pattern PCRE matches Perl matches
2203
2204 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2205 \Qabc\$xyz\E abc\$xyz abc\$xyz
2206 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2207
2208 For compatibility with Perl, \Q...\E sequences are recognized inside character
2209 classes as well as outside them.
2210
2211 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2212 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2213 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2214 signed/unsigned warnings.
2215
2216 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2217 option for pcretest, so I've replaced it by a simple function that does just
2218 that job.
2219
2220 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2221 "pcregrep -".
2222
2223 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2224 Java package. This provides some syntactic sugar for simple cases of what my
2225 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2226 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2227 item, you can use this simplified notation. Note that only makes sense with
2228 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2229 greediness, whatever the setting of the PCRE_UNGREEDY option.
2230
2231 13. A change of greediness default within a pattern was not taking effect at
2232 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2233 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2234 was abstracted outside.
2235
2236 14. PCRE now supports the \G assertion. It is true when the current matching
2237 position is at the start point of the match. This differs from \A when the
2238 starting offset is non-zero. Used with the /g option of pcretest (or similar
2239 code), it works in the same way as it does for Perl's /g option. If all
2240 alternatives of a regex begin with \G, the expression is anchored to the start
2241 match position, and the "anchored" flag is set in the compiled expression.
2242
2243 15. Some bugs concerning the handling of certain option changes within patterns
2244 have been fixed. These applied to options other than (?ims). For example,
2245 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2246 been the other way round. Some of this was related to change 7 above.
2247
2248 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2249 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2250 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2251 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2252
2253 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2254 mode. Unlike ".", it always matches newline, whatever the setting of
2255 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2256 assertions. Perl allows it, but it doesn't (in general) work because it can't
2257 calculate the length of the lookbehind. At least, that's the case for Perl
2258 5.8.0 - I've been told they are going to document that it doesn't work in
2259 future.
2260
2261 18. Added an error diagnosis for escapes that PCRE does not support: these are
2262 \L, \l, \N, \P, \p, \U, \u, and \X.
2263
2264 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2265 reading past the end of the pattern in cases such as /[abcd/.
2266
2267 20. PCRE was getting more memory than necessary for patterns with classes that
2268 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2269
2270 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2271 compiling PCRE for use with Virtual Pascal.
2272
2273 22. Small fix to the Makefile to make it work properly if the build is done
2274 outside the source tree.
2275
2276 23. Added a new extension: a condition to go with recursion. If a conditional
2277 subpattern starts with (?(R) the "true" branch is used if recursion has
2278 happened, whereas the "false" branch is used only at the top level.
2279
2280 24. When there was a very long string of literal characters (over 255 bytes
2281 without UTF support, over 250 bytes with UTF support), the computation of how
2282 much memory was required could be incorrect, leading to segfaults or other
2283 strange effects.
2284
2285 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2286 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2287 there was a subsequent back reference to those brackets. This meant that, for
2288 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2289 possible to check for precisely this case. All we can do is abandon the
2290 optimization if .* occurs inside capturing brackets when there are any back
2291 references whatsoever. (See below for a better fix that came later.)
2292
2293 26. The handling of the optimization for finding the first character of a
2294 non-anchored pattern, and for finding a character that is required later in the
2295 match were failing in some cases. This didn't break the matching; it just
2296 failed to optimize when it could. The way this is done has been re-implemented.
2297
2298 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2299
2300 28. Added a new feature that provides some of the functionality that Perl
2301 provides with (?{...}). The facility is termed a "callout". The way it is done
2302 in PCRE is for the caller to provide an optional function, by setting
2303 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2304 global variable. By default it is unset, which disables all calling out. To get
2305 the function called, the regex must include (?C) at appropriate points. This
2306 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2307 This provides a means of identifying different callout points. When PCRE
2308 reaches such a point in the regex, if pcre_callout has been set, the external
2309 function is called. It is provided with data in a structure called
2310 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2311 matching continues; if it returns a non-zero value, the match at the current
2312 point fails. However, backtracking will occur if possible. [This was changed
2313 later and other features added - see item 49 below.]
2314
2315 29. pcretest is upgraded to test the callout functionality. It provides a
2316 callout function that displays information. By default, it shows the start of
2317 the match and the current position in the text. There are some new data escapes
2318 to vary what happens:
2319
2320 \C+ in addition, show current contents of captured substrings
2321 \C- do not supply a callout function
2322 \C!n return 1 when callout number n is reached
2323 \C!n!m return 1 when callout number n is reached for the mth time
2324
2325 30. If pcregrep was called with the -l option and just a single file name, it
2326 output "<stdin>" if a match was found, instead of the file name.
2327
2328 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2329 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2330 pcre_exec(). This saves a malloc/free per call. The default value of
2331 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2332 when configuring.
2333
2334 32. The default maximum size of a compiled pattern is 64K. There have been a
2335 few cases of people hitting this limit. The code now uses macros to handle the
2336 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2337 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2338 configuring. Tests 2 and 5 work only with 2-byte links because they output
2339 debugging information about compiled patterns.
2340
2341 33. Internal code re-arrangements:
2342
2343 (a) Moved the debugging function for printing out a compiled regex into
2344 its own source file (printint.c) and used #include to pull it into
2345 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2346 separate copies.
2347
2348 (b) Defined the list of op-code names for debugging as a macro in
2349 internal.h so that it is next to the definition of the opcodes.
2350
2351 (c) Defined a table of op-code lengths for simpler skipping along compiled
2352 code. This is again a macro in internal.h so that it is next to the
2353 definition of the opcodes.
2354
2355 34. Added support for recursive calls to individual subpatterns, along the
2356 lines of Robin Houston's patch (but implemented somewhat differently).
2357
2358 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2359 allow it to read and process whole directories in Win32. This code was
2360 contributed by Lionel Fourquaux; it has not been tested by me.
2361
2362 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2363 used to name a group. Names consist of alphanumerics and underscores, and must
2364 be unique. Back references use the syntax (?P=name) and recursive calls use
2365 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2366 numbers. The function pcre_fullinfo() can be used after compilation to extract
2367 a name/number map. There are three relevant calls:
2368
2369 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2370 PCRE_INFO_NAMECOUNT yields the number of entries
2371 PCRE_INFO_NAMETABLE yields a pointer to the map.
2372
2373 The map is a vector of fixed-size entries. The size of each entry depends on
2374 the length of the longest name used. The first two bytes of each entry are the
2375 group number, most significant byte first. There follows the corresponding
2376 name, zero terminated. The names are in alphabetical order.
2377
2378 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2379 case instead of 255. Making it the same both with and without UTF-8 support
2380 means that the same test output works with both.
2381
2382 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2383 calling malloc() with a zero argument.
2384
2385 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2386 optimization. I've improved things by keeping a bitmap of backreferences with
2387 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2388 fact referenced, the optimization can be applied. It is unlikely that a
2389 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2390 the match to follow \n) will appear inside brackets with a number greater than
2391 31, but if it does, any back reference > 31 suppresses the optimization.
2392
2393 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2394 of disabling numbered capturing parentheses. Any opening parenthesis that is
2395 not followed by ? behaves as if it were followed by ?: but named parentheses
2396 can still be used for capturing (and they will acquire numbers in the usual
2397 way).
2398
2399 41. Redesigned the return codes from the match() function into yes/no/error so
2400 that errors can be passed back from deep inside the nested calls. A malloc
2401 failure while inside a recursive subpattern call now causes the
2402 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2403
2404 42. It is now possible to set a limit on the number of times the match()
2405 function is called in a call to pcre_exec(). This facility makes it possible to
2406 limit the amount of recursion and backtracking, though not in a directly
2407 obvious way, because the match() function is used in a number of different
2408 circumstances. The count starts from zero for each position in the subject
2409 string (for non-anchored patterns). The default limit is, for compatibility, a
2410 large number, namely 10 000 000. You can change this in two ways:
2411
2412 (a) When configuring PCRE before making, you can use --with-match-limit=n
2413 to set a default value for the compiled library.
2414
2415 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2416 a different value is set. See 45 below.
2417
2418 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2419
2420 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2421 of things that can be changed at compile time. The first argument specifies
2422 what is wanted and the second points to where the information is to be placed.
2423 The current list of available information is:
2424
2425 PCRE_CONFIG_UTF8
2426
2427 The output is an integer that is set to one if UTF-8 support is available;
2428 otherwise it is set to zero.
2429
2430 PCRE_CONFIG_NEWLINE
2431
2432 The output is an integer that it set to the value of the code that is used for
2433 newline. It is either LF (10) or CR (13).
2434
2435 PCRE_CONFIG_LINK_SIZE
2436
2437 The output is an integer that contains the number of bytes used for internal
2438 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2439
2440 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2441
2442 The output is an integer that contains the threshold above which the POSIX
2443 interface uses malloc() for output vectors. See item 31 above.
2444
2445 PCRE_CONFIG_MATCH_LIMIT
2446
2447 The output is an unsigned integer that contains the default limit of the number
2448 of match() calls in a pcre_exec() execution. See 42 above.
2449
2450 44. pcretest has been upgraded by the addition of the -C option. This causes it
2451 to extract all the available output from the new pcre_config() function, and to
2452 output it. The program then exits immediately.
2453
2454 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2455 order to support additional features. One way would have been to define
2456 pcre_exec2() (for example) with extra arguments, but this would not have been
2457 extensible, and would also have required all calls to the original function to
2458 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2459 is used for passing in "extra" data from pcre_study().
2460
2461 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2462 contains the following fields:
2463
2464 flags a bitmap indicating which of the following fields are set
2465 study_data opaque data from pcre_study()
2466 match_limit a way of specifying a limit on match() calls for a specific
2467 call to pcre_exec()
2468 callout_data data for callouts (see 49 below)
2469
2470 The flag bits are also defined in pcre.h, and are
2471
2472 PCRE_EXTRA_STUDY_DATA
2473 PCRE_EXTRA_MATCH_LIMIT
2474 PCRE_EXTRA_CALLOUT_DATA
2475
2476 The pcre_study() function now returns one of these new pcre_extra blocks, with
2477 the actual study data pointed to by the study_data field, and the
2478 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2479 before. That is, this change is entirely upwards-compatible and requires no
2480 change to existing code.
2481
2482 If you want to pass in additional data to pcre_exec(), you can either place it
2483 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2484 block.
2485
2486 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2487 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2488 times with different match limits, until it finds the minimum value needed for
2489 pcre_exec() to complete. The value is then output. This can be instructive; for
2490 most simple matches the number is quite small, but for pathological cases it
2491 gets very large very quickly.
2492
2493 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2494 returns the size of the data block pointed to by the study_data field in a
2495 pcre_extra block, that is, the value that was passed as the argument to
2496 pcre_malloc() when PCRE was getting memory in which to place the information
2497 created by pcre_study(). The fourth argument should point to a size_t variable.
2498 pcretest has been extended so that this information is shown after a successful
2499 pcre_study() call when information about the compiled regex is being displayed.
2500
2501 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2502 because what follows is always an absolute path. (Later: it turns out that this
2503 is more than cosmetic for MinGW, because it doesn't like empty path
2504 components.)
2505
2506 49. Some changes have been made to the callout feature (see 28 above):
2507
2508 (i) A callout function now has three choices for what it returns:
2509
2510 0 => success, carry on matching
2511 > 0 => failure at this point, but backtrack if possible
2512 < 0 => serious error, return this value from pcre_exec()
2513
2514 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2515 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2516 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2517 use by callout functions. It will never be used by PCRE itself.
2518
2519 (ii) The pcre_extra structure (see 45 above) has a void * field called
2520 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2521 pcre_callout_block structure has a field of the same name. The contents of
2522 the field passed in the pcre_extra structure are passed to the callout
2523 function in the corresponding field in the callout block. This makes it
2524 easier to use the same callout-containing regex from multiple threads. For
2525 testing, the pcretest program has a new data escape
2526
2527 \C*n pass the number n (may be negative) as callout_data
2528
2529 If the callout function in pcretest receives a non-zero value as
2530 callout_data, it returns that value.
2531
2532 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2533 there were some redundant $(CFLAGS) in commands that are now specified as
2534 $(LINK), which already includes $(CFLAGS).
2535
2536 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2537 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2538 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2539 one-byte characters throughout. Note that case-insensitive matching applies
2540 only to characters whose values are less than 256. PCRE doesn't support the
2541 notion of cases for higher-valued characters.
2542
2543 (i) A character class whose characters are all within 0-255 is handled as
2544 a bit map, and the map is inverted for negative classes. Previously, a
2545 character > 255 always failed to match such a class; however it should
2546 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2547
2548 (ii) A negated character class with a single character < 255 is coded as
2549 "not this character" (OP_NOT). This wasn't working properly when the test
2550 character was multibyte, either singly or repeated.
2551
2552 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2553 mode, for example: \x{100}{2,3}.
2554
2555 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2556 singly or repeated) now correctly test multibyte characters. However,
2557 PCRE doesn't recognize any characters with values greater than 255 as
2558 digits, spaces, or word characters. Such characters always match \D, \S,
2559 and \W, and never match \d, \s, or \w.
2560
2561 (v) Classes may now contain characters and character ranges with values
2562 greater than 255. For example: [ab\x{100}-\x{400}].
2563
2564 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2565 PCRE in UTF-8 mode.
2566
2567 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2568 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2569 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2570 value.)
2571
2572 53. The single man page has become too large. I have therefore split it up into
2573 a number of separate man pages. These also give rise to individual HTML pages;
2574 these are now put in a separate directory, and there is an index.html page that
2575 lists them all. Some hyperlinking between the pages has been installed.
2576
2577 54. Added convenience functions for handling named capturing parentheses.
2578
2579 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2580 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2581 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2582 are faulted.
2583
2584 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2585 calling configure. These values are used when compiling the dftables.c program
2586 which is run to generate the source of the default character tables. They
2587 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2588 you will need to set these values.
2589
2590 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2591
2592
2593 Version 3.9 02-Jan-02
2594 ---------------------
2595
2596 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2597
2598 2. If --disable-static was given, the building process failed when trying to
2599 build pcretest and pcregrep. (For some reason it was using libtool to compile
2600 them, which is not right, as they aren't part of the library.)
2601
2602
2603 Version 3.8 18-Dec-01
2604 ---------------------
2605
2606 1. The experimental UTF-8 code was completely screwed up. It was packing the
2607 bytes in the wrong order. How dumb can you get?
2608
2609
2610 Version 3.7 29-Oct-01
2611 ---------------------
2612
2613 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2614 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2615 this didn't happen under Solaris 8, where I normally test things.
2616
2617 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2618 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2619 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2620 this fix an hour or so after the initial 3.7 release.)
2621
2622
2623 Version 3.6 23-Oct-01
2624 ---------------------
2625
2626 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2627 offsets passed as NULL with zero offset count.
2628
2629 2. The config.guess and config.sub files had not been updated when I moved to
2630 the latest autoconf.
2631
2632
2633 Version 3.5 15-Aug-01
2634 ---------------------
2635
2636 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2637 had been forgotten.
2638
2639 2. By using declared but undefined structures, we can avoid using "void"
2640 definitions in pcre.h while keeping the internal definitions of the structures
2641 private.
2642
2643 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2644 user point of view, this means that both static and shared libraries are built
2645 by default, but this can be individually controlled. More of the work of
2646 handling this static/shared cases is now inside libtool instead of PCRE's make
2647 file.
2648
2649 4. The pcretest utility is now installed along with pcregrep because it is
2650 useful for users (to test regexs) and by doing this, it automatically gets
2651 relinked by libtool. The documentation has been turned into a man page, so
2652 there are now .1, .txt, and .html versions in /doc.
2653
2654 5. Upgrades to pcregrep:
2655 (i) Added long-form option names like gnu grep.
2656 (ii) Added --help to list all options with an explanatory phrase.
2657 (iii) Added -r, --recursive to recurse into sub-directories.
2658 (iv) Added -f, --file to read patterns from a file.
2659
2660 6. pcre_exec() was referring to its "code" argument before testing that
2661 argument for NULL (and giving an error if it was NULL).
2662
2663 7. Upgraded Makefile.in to allow for compiling in a different directory from
2664 the source directory.
2665
2666 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2667 options bits, the pointer it was passed was to an int instead of to an unsigned
2668 long int. This mattered only on 64-bit systems.
2669
2670 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2671 generated) instead of pcre.in, which it its source. Also made the same change
2672 in several of the .c files.
2673
2674 10. A new release of gcc defines printf() as a macro, which broke pcretest
2675 because it had an ifdef in the middle of a string argument for printf(). Fixed
2676 by using separate calls to printf().
2677
2678 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2679 script, to force use of CR or LF instead of \n in the source. On non-Unix
2680 systems, the value can be set in config.h.
2681
2682 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2683 absolute limit. Changed the text of the error message to make this clear, and
2684 likewise updated the man page.
2685
2686 13. The limit of 99 on the number of capturing subpatterns has been removed.
2687 The new limit is 65535, which I hope will not be a "real" limit.
2688
2689
2690 Version 3.4 22-Aug-00
2691 ---------------------
2692
2693 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2694
2695 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2696
2697
2698 Version 3.3 01-Aug-00
2699 ---------------------
2700
2701 1. If an octal character was given, but the value was greater than \377, it
2702 was not getting masked to the least significant bits, as documented. This could
2703 lead to crashes in some systems.
2704
2705 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2706 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2707
2708 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2709 These just pass their arguments on to (pcre_free)(), but they are provided
2710 because some uses of PCRE bind it to non-C systems that can call its functions,
2711 but cannot call free() or pcre_free() directly.
2712
2713 4. Add "make test" as a synonym for "make check". Corrected some comments in
2714 the Makefile.
2715
2716 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2717 Makefile.
2718
2719 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2720 command called pgrep for grepping around the active processes.
2721
2722 7. Added the beginnings of support for UTF-8 character strings.
2723
2724 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2725 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2726 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2727 out for the ar command.)
2728
2729
2730 Version 3.2 12-May-00
2731 ---------------------
2732
2733 This is purely a bug fixing release.
2734
2735 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2736 of ZA. This was just one example of several cases that could provoke this bug,
2737 which was introduced by change 9 of version 2.00. The code for breaking
2738 infinite loops after an iteration that matches an empty string was't working
2739 correctly.
2740
2741 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2742 when matched against abbab (for example). After matching an empty string, it
2743 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2744 caused it to match further down the string than it should.
2745
2746 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2747 was there because it doesn't seem to be needed, and it causes trouble on some
2748 systems, as it is not a Standard C header. It has been removed.
2749
2750 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2751 were reported on the Macintosh. The changes were from
2752
2753 while ((c = *(++ptr)) != 0 && c != '\n');
2754 to
2755 while ((c = *(++ptr)) != 0 && c != '\n') ;
2756
2757 Totally extraordinary, but if that's what it takes...
2758
2759 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2760 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2761 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2762 assumes the way PCRE uses memmove() (always moving upwards).
2763
2764 6. PCRE is being used in one environment where strchr() is not available. There
2765 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2766 faster code anyway.
2767
2768
2769 Version 3.1 09-Feb-00
2770 ---------------------
2771
2772 The only change in this release is the fixing of some bugs in Makefile.in for
2773 the "install" target:
2774
2775 (1) It was failing to install pcreposix.h.
2776
2777 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2778
2779
2780 Version 3.0 01-Feb-00
2781 ---------------------
2782
2783 1. Add support for the /+ modifier to perltest (to output $` like it does in
2784 pcretest).
2785
2786 2. Add support for the /g modifier to perltest.
2787
2788 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2789 matches null strings.
2790
2791 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2792 pattern. Perl treats empty patterns specially - it reuses the most recent
2793 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2794 effect.
2795
2796 5. The POSIX interface was broken in that it was just handing over the POSIX
2797 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2798 required a bigger vector, with some working space on the end. This means that
2799 the POSIX wrapper now has to get and free some memory, and copy the results.
2800
2801 6. Added some simple autoconf support, placing the test data and the
2802 documentation in separate directories, re-organizing some of the
2803 information files, and making it build pcre-config (a GNU standard). Also added
2804 libtool support for building PCRE as a shared library, which is now the
2805 default.
2806
2807 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2808 09 are not valid octal constants. Single digits will be used for minor values
2809 less than 10.
2810
2811 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2812 existing programs that set these in the POSIX interface can use PCRE without
2813 modification.
2814
2815 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2816 return all that pcre_info() returns, plus additional data. The pcre_info()
2817 function is retained for compatibility, but is considered to be obsolete.
2818
2819 10. Added experimental recursion feature (?R) to handle one common case that
2820 Perl 5.6 will be able to do with (?p{...}).
2821
2822 11. Added support for POSIX character classes like [:alpha:], which Perl is
2823 adopting.
2824
2825
2826 Version 2.08 31-Aug-99
2827 ----------------------
2828
2829 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2830 trying to match at the startoffset position, but instead was moving forward to
2831 the next newline as if a previous match had failed.
2832
2833 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2834 and could get into a loop if a null string was matched other than at the start
2835 of the subject.
2836
2837 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2838 be distinguished at compile time, and for completeness also added PCRE_DATE.
2839
2840 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2841 in GnuWin32 environments.
2842
2843
2844 Version 2.07 29-Jul-99
2845 ----------------------
2846
2847 1. The documentation is now supplied in plain text form and HTML as well as in
2848 the form of man page sources.
2849
2850 2. C++ compilers don't like assigning (void *) values to other pointer types.
2851 In particular this affects malloc(). Although there is no problem in Standard
2852 C, I've put in casts to keep C++ compilers happy.
2853
2854 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2855 should be (const char *).
2856
2857 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2858 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2859 However, I haven't made this a standard facility. The documentation doesn't
2860 mention it, and the Makefile doesn't support it.
2861
2862 5. The Makefile now contains an "install" target, with editable destinations at
2863 the top of the file. The pcretest program is not installed.
2864
2865 6. pgrep -V now gives the PCRE version number and date.
2866
2867 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2868 causing the entire string to be ignored, instead of just the last character.
2869
2870 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2871 non-matching string, it can take a very, very long time, even for strings of
2872 quite modest length, because of the nested recursion. PCRE now does better in
2873 some of these cases. It does this by remembering the last required literal
2874 character in the pattern, and pre-searching the subject to ensure it is present
2875 before running the real match. In other words, it applies a heuristic to detect
2876 some types of certain failure quickly, and in the above example, if presented
2877 with a string that has no trailing " it gives "no match" very quickly.
2878
2879 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2880 other alternatives are tried instead.
2881
2882
2883 Version 2.06 09-Jun-99
2884 ----------------------
2885
2886 1. Change pcretest's output for amount of store used to show just the code
2887 space, because the remainder (the data block) varies in size between 32-bit and
2888 64-bit systems.
2889
2890 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2891 start matching at. This allows lookbehinds to work when searching for multiple
2892 occurrences in a string.
2893
2894 3. Added additional options to pcretest for testing multiple occurrences:
2895
2896 /+ outputs the rest of the string that follows a match
2897 /g loops for multiple occurrences, using the new startoffset argument
2898 /G loops for multiple occurrences by passing an incremented pointer
2899
2900 4. PCRE wasn't doing the "first character" optimization for patterns starting
2901 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2902 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2903 the letter 'x'. On long subject strings, this gives a significant speed-up.
2904
2905
2906 Version 2.05 21-Apr-99
2907 ----------------------
2908
2909 1. Changed the type of magic_number from int to long int so that it works
2910 properly on 16-bit systems.
2911
2912 2. Fixed a bug which caused patterns starting with .* not to work correctly
2913 when the subject string contained newline characters. PCRE was assuming
2914 anchoring for such patterns in all cases, which is not correct because .* will
2915 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2916 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2917 must be retried after every newline in the subject.
2918
2919
2920 Version 2.04 18-Feb-99
2921 ----------------------
2922
2923 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2924 computation of the store needed to hold the pattern was incorrect (too large).
2925 If such patterns were nested a few deep, this could multiply and become a real
2926 problem.
2927
2928 2. Added /M option to pcretest to show the memory requirement of a specific
2929 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2930
2931 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2932 compiled in such a way that the backtracking after subsequent failure was
2933 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2934 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2935
2936
2937 Version 2.03 02-Feb-99
2938 ----------------------
2939
2940 1. Fixed typo and small mistake in man page.
2941
2942 2. Added 4th condition (GPL supersedes if conflict) and created separate
2943 LICENCE file containing the conditions.
2944
2945 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2946 Perl, that is the internal \ allows the delimiter to be included in the
2947 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2948 the final delimiter, add \ to the end of the pattern (to test the error).
2949
2950 4. Added the convenience functions for extracting substrings after a successful
2951 match. Updated pcretest to make it able to test these functions.
2952
2953
2954 Version 2.02 14-Jan-99
2955 ----------------------
2956
2957 1. Initialized the working variables associated with each extraction so that
2958 their saving and restoring doesn't refer to uninitialized store.
2959
2960 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2961 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2962 fix the problem.
2963
2964 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2965 calls, and wasn't printing the correct value for compiling calls. Increased the
2966 default value of LOOPREPEAT, and the number of significant figures in the
2967 times.
2968
2969 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2970
2971 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2972 a building problem on Windows NT with a FAT file system.
2973
2974
2975 Version 2.01 21-Oct-98
2976 ----------------------
2977
2978 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2979 to character tables built by pcre_maketables() in the current locale. If NULL
2980 is passed, the default tables are used.
2981
2982
2983 Version 2.00 24-Sep-98
2984 ----------------------
2985
2986 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2987 it any more.
2988
2989 2. Allow quantification of (?>) groups, and make it work correctly.
2990
2991 3. The first character computation wasn't working for (?>) groups.
2992
2993 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2994 end of the subject) and add 5.005's \z, which really does match only at the
2995 very end of the subject.
2996
2997 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2998
2999 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3000 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3001 localized options. All options to pcre_study() were also removed.
3002
3003 7. Add other new features from 5.005:
3004
3005 $(?<= positive lookbehind
3006 $(?<! negative lookbehind
3007 (?imsx-imsx) added the unsetting capability
3008 such a setting is global if at outer level; local otherwise
3009 (?imsx-imsx:) non-capturing groups with option setting
3010 (?(cond)re|re) conditional pattern matching
3011
3012 A backreference to itself in a repeated group matches the previous
3013 captured string.
3014
3015 8. General tidying up of studying (both automatic and via "study")
3016 consequential on the addition of new assertions.
3017
3018 9. As in 5.005, unlimited repeated groups that could match an empty substring
3019 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3020 runtime if any iteration does actually match an empty substring.
3021
3022 10. Include the RunTest script in the distribution.
3023
3024 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3025 discrepancies, some of which were old and were also with respect to 5.004. They
3026 have now been fixed.
3027
3028
3029 Version 1.09 28-Apr-98
3030 ----------------------
3031
3032 1. A negated single character class followed by a quantifier with a minimum
3033 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3034 program crashes, or just wrong answers. This did not apply to negated classes
3035 containing more than one character, or to minima other than one.
3036
3037
3038 Version 1.08 27-Mar-98
3039 ----------------------
3040
3041 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3042
3043 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3044 latter must appear before anything that relies on it in the pattern.
3045
3046
3047 Version 1.07 16-Feb-98
3048 ----------------------
3049
3050 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3051 repeat of a potentially empty string).
3052
3053
3054 Version 1.06 23-Jan-98
3055 ----------------------
3056
3057 1. Added Markus Oberhumer's little patches for C++.
3058
3059 2. Literal strings longer than 255 characters were broken.
3060
3061
3062 Version 1.05 23-Dec-97
3063 ----------------------
3064
3065 1. Negated character classes containing more than one character were failing if
3066 PCRE_CASELESS was set at run time.
3067
3068
3069 Version 1.04 19-Dec-97
3070 ----------------------
3071
3072 1. Corrected the man page, where some "const" qualifiers had been omitted.
3073
3074 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3075 input syntax.
3076
3077 3. Fixed memory leak which occurred when a regex with back references was
3078 matched with an offsets vector that wasn't big enough. The temporary memory
3079 that is used in this case wasn't being freed if the match failed.
3080
3081 4. Tidied pcretest to ensure it frees memory that it gets.
3082
3083 5. Temporary memory was being obtained in the case where the passed offsets
3084 vector was exactly big enough.
3085
3086 6. Corrected definition of offsetof() from change 5 below.
3087
3088 7. I had screwed up change 6 below and broken the rules for the use of
3089 setjmp(). Now fixed.
3090
3091
3092 Version 1.03 18-Dec-97
3093 ----------------------
3094
3095 1. A erroneous regex with a missing opening parenthesis was correctly
3096 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3097 on some systems.
3098
3099 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3100 it was reported that one broken compiler failed on the former because "code" is
3101 also an independent variable.
3102
3103 3. The erroneous regex a[]b caused an array overrun reference.
3104
3105 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3106 fail on data ending with that character. (It was going on too far, and checking
3107 the next character, typically a binary zero.) This was specific to the
3108 optimized code for single-character negative classes.
3109
3110 5. Added a contributed patch from the TIN world which does the following:
3111
3112 + Add an undef for memmove, in case the the system defines a macro for it.
3113
3114 + Add a definition of offsetof(), in case there isn't one. (I don't know
3115 the reason behind this - offsetof() is part of the ANSI standard - but
3116 it does no harm).
3117
3118 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3119 most of the places where whitespace preceded '#'. I have given up and
3120 allowed the remaining 2 cases to be at the margin.
3121
3122 + Rename some variables in pcre to eliminate shadowing. This seems very
3123 pedantic, but does no harm, of course.
3124
3125 6. Moved the call to setjmp() into its own function, to get rid of warnings
3126 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3127
3128 7. Constructs such as \d{8,} were compiling into the equivalent of
3129 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3130 outcome, but in this particular case used more store than had been allocated,
3131 which caused the bug to be discovered because it threw up an internal error.
3132
3133 8. The debugging code in both pcre and pcretest for outputting the compiled
3134 form of a regex was going wrong in the case of back references followed by
3135 curly-bracketed repeats.
3136
3137
3138 Version 1.02 12-Dec-97
3139 ----------------------
3140
3141 1. Typos in pcre.3 and comments in the source fixed.
3142
3143 2. Applied a contributed patch to get rid of places where it used to remove
3144 'const' from variables, and fixed some signed/unsigned and uninitialized
3145 variable warnings.
3146
3147 3. Added the "runtest" target to Makefile.
3148
3149 4. Set default compiler flag to -O2 rather than just -O.
3150
3151
3152 Version 1.01 19-Nov-97
3153 ----------------------
3154
3155 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3156 like /([ab]*)*/, that is, for classes with more than one character in them.
3157
3158 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3159 as /((?>a*))*/ (a PCRE_EXTRA facility).
3160
3161
3162 Version 1.00 18-Nov-97
3163 ----------------------
3164
3165 1. Added compile-time macros to support systems such as SunOS4 which don't have
3166 memmove() or strerror() but have other things that can be used instead.
3167
3168 2. Arranged that "make clean" removes the executables.
3169
3170
3171 Version 0.99 27-Oct-97
3172 ----------------------
3173
3174 1. Fixed bug in code for optimizing classes with only one character. It was
3175 initializing a 32-byte map regardless, which could cause it to run off the end
3176 of the memory it had got.
3177
3178 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3179
3180
3181 Version 0.98 22-Oct-97
3182 ----------------------
3183
3184 1. Fixed bug in code for handling temporary memory usage when there are more
3185 back references than supplied space in the ovector. This could cause segfaults.
3186
3187
3188 Version 0.97 21-Oct-97
3189 ----------------------
3190
3191 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3192
3193 2. Optimized negated single characters not to use a bit map.
3194
3195 3. Brought error texts together as macro definitions; clarified some of them;
3196 fixed one that was wrong - it said "range out of order" when it meant "invalid
3197 escape sequence".
3198
3199 4. Changed some char * arguments to const char *.
3200
3201 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3202
3203 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3204 pcretest.
3205
3206
3207 Version 0.96 16-Oct-97
3208 ----------------------
3209
3210 1. Added a simple "pgrep" utility to the distribution.
3211
3212 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3213 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3214 where "ddd" means "one or more decimal digits".
3215
3216 3. Fixed serious bug. If a pattern had a back reference, but the call to
3217 pcre_exec() didn't supply a large enough ovector to record the related
3218 identifying subpattern, the match always failed. PCRE now remembers the number
3219 of the largest back reference, and gets some temporary memory in which to save
3220 the offsets during matching if necessary, in order to ensure that
3221 backreferences always work.
3222
3223 4. Increased the compatibility with Perl in a number of ways:
3224
3225 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3226 to request this handling. The option can be set at compile or exec time.
3227
3228 (b) $ matches before a terminating newline by default; an option
3229 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3230 mode). The option can be set at compile or exec time.
3231
3232 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3233 the same as Perl's. If the decimal number it represents is less than 10
3234 or there aren't that many previous left capturing parentheses, an octal
3235 escape is read. Inside a character class, it's always an octal escape,
3236 even if it is a single digit.
3237
3238 (d) An escaped but undefined alphabetic character is taken as a literal,
3239 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3240 escapes.
3241
3242 (e) {0} is now permitted. (The previous item is removed from the compiled
3243 pattern).
3244
3245 5. Changed all the names of code files so that the basic parts are no longer
3246 than 10 characters, and abolished the teeny "globals.c" file.
3247
3248 6. Changed the handling of character classes; they are now done with a 32-byte
3249 bit map always.
3250
3251 7. Added the -d and /D options to pcretest to make it possible to look at the
3252 internals of compilation without having to recompile pcre.
3253
3254
3255 Version 0.95 23-Sep-97
3256 ----------------------
3257
3258 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3259 \x20 at the start of a run of normal characters. These were being treated as
3260 real characters, instead of the source characters being re-checked.
3261
3262
3263 Version 0.94 18-Sep-97
3264 ----------------------
3265
3266 1. The functions are now thread-safe, with the caveat that the global variables
3267 containing pointers to malloc() and free() or alternative functions are the
3268 same for all threads.
3269
3270 2. Get pcre_study() to generate a bitmap of initial characters for non-
3271 anchored patterns when this is possible, and use it if passed to pcre_exec().
3272
3273
3274 Version 0.93 15-Sep-97
3275 ----------------------
3276
3277 1. /(b)|(:+)/ was computing an incorrect first character.
3278
3279 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3280 but not actually doing anything yet.
3281
3282 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3283 as Perl does (e.g. [-az] or [az-]).
3284
3285 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3286 all possible positions.
3287
3288 5. Split up into different modules to avoid including unneeded functions in a
3289 compiled binary. However, compile and exec are still in one module. The "study"
3290 function is split off.
3291
3292 6. The character tables are now in a separate module whose source is generated
3293 by an auxiliary program - but can then be edited by hand if required. There are
3294 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3295 toupper() in the code.
3296
3297 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3298 make them global. Abolish the function for setting them, as the caller can now
3299 set them directly.
3300
3301
3302 Version 0.92 11-Sep-97
3303 ----------------------
3304
3305 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3306 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3307
3308 2. Caseless matching was not working in character classes if the characters in
3309 the pattern were in upper case.
3310
3311 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3312
3313 4. Make PCRE_ANCHORED public and accept as a compile option.
3314
3315 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3316 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3317 pass them.
3318
3319 6. Give an error if bad option bits passed at compile or run time.
3320
3321 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3322 pcretest to cause it to pass that flag.
3323
3324 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3325 options, and the first character, if set.
3326
3327 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3328
3329
3330 Version 0.91 10-Sep-97
3331 ----------------------
3332
3333 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3334 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3335
3336 2. PCRE was looping on encountering an indefinitely repeated back reference to
3337 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3338 Perl does - treats the match as successful.
3339
3340 ****

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