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Revision 286 - (hide annotations) (download)
Mon Dec 17 14:46:11 2007 UTC (7 years, 4 months ago) by ph10
File size: 146126 byte(s)
Add .gz and .bz2 optional support to pcregrep.

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


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