ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log

Revision 287 - (hide annotations) (download)
Tue Dec 18 20:11:28 2007 UTC (7 years, 4 months ago) by ph10
File size: 146168 byte(s)
Added --enable-pcretest-libreadline.

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.
96 ph10 287 18. Added --enable-pcretest-libreadline.
97 ph10 286
98 ph10 287
99 ph10 260 Version 7.4 21-Sep-07
100 ph10 230 ---------------------
102     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
103 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
104     LF". That isn't really right - the whole point of the change was to try to
105     help when there was an actual mention of one of the two characters. So now
106     the change happens only if \r or \n (or a literal CR or LF) character is
107 ph10 230 encountered.
108 ph10 231
109     2. The 32-bit options word was also used for 6 internal flags, but the numbers
110     of both had grown to the point where there were only 3 bits left.
111     Fortunately, there was spare space in the data structure, and so I have
112     moved the internal flags into a new 16-bit field to free up more option
113 ph10 230 bits.
114 ph10 231
115     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
116     but did not set the internal JCHANGED flag - either of these is enough to
117     control the way the "get" function works - but the PCRE_INFO_JCHANGED
118     facility is supposed to tell if (?J) was ever used, so now (?J) at the
119 ph10 230 start sets both bits.
121 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
122     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
123 ph10 230
124 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
126     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
127 ph10 233 compatibility, even though it is no longer used.
128 ph10 243
129     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
130 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
131 ph10 259 windows.h file is present (where different names are used). [This was
132 ph10 257 reversed later after testing - see 16 below.]
133 ph10 243
134     8. Changed all #include <config.h> to #include "config.h". There were also
135 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
136 ph10 243
137 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
138 ph10 243 sequence off the lines that it output.
140     10. It was pointed out to me that arrays of string pointers cause lots of
141     relocations when a shared library is dynamically loaded. A technique of
142     using a single long string with a table of offsets can drastically reduce
143     these. I have refactored PCRE in four places to do this. The result is
144 ph10 240 dramatic:
145 ph10 243
146 ph10 240 Originally: 290
147     After changing UCP table: 187
148 ph10 243 After changing error message table: 43
149 ph10 240 After changing table of "verbs" 36
150     After changing table of Posix names 22
151 ph10 243
152 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
153 ph10 247
154 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
155 ph10 247 unicode-properties was also set.
157 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
158 ph10 231
159 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
160     checked only for CRLF.
161 ph10 233
162 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
164 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
165 ph10 253
166 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
167 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
168     entirely. This removes changes made in 7 above.
169 ph10 256
170 ph10 261 17. The CMake files have been updated, and there is now more information about
171     building with CMake in the NON-UNIX-USE document.
172 ph10 257
173 ph10 261
174 ph10 228 Version 7.3 28-Aug-07
175 ph10 157 ---------------------
177 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
178     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
179     brackets there is not right, since it causes compilers to look for an
180     installed pcre.h, not the version that is in the source that is being
181     compiled (which of course may be different). I have changed it back to:
182 ph10 197
183 ph10 189 #include "pcre.h"
184 ph10 197
185     I have a vague recollection that the change was concerned with compiling in
186     different directories, but in the new build system, that is taken care of
187     by the VPATH setting the Makefile.
189 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
190     when the subject happened to end in the byte 0x85 (e.g. if the last
191     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
192     characters but of course it shouldn't be taken as a newline when it is part
193     of another character. The bug was that, for an unlimited repeat of . in
194     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
195     characters when looking for a newline.
196 ph10 197
197     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
199     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
200     in debug output.
202 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
203     long printing in the pcrecpp unittest when running under MinGW.
204 ph10 189
205 ph10 197 6. ESC_K was left out of the EBCDIC table.
206 ph10 189
207 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
208     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
209     limit also applies to "virtual nesting" when a pattern is recursive, and in
210     this case 1000 isn't so big. I have been able to remove this limit at the
211     expense of backing off one optimization in certain circumstances. Normally,
212     when pcre_exec() would call its internal match() function recursively and
213     immediately return the result unconditionally, it uses a "tail recursion"
214     feature to save stack. However, when a subpattern that can match an empty
215     string has an unlimited repetition quantifier, it no longer makes this
216     optimization. That gives it a stack frame in which to save the data for
217     checking that an empty string has been matched. Previously this was taken
218     from the 1000-entry workspace that had been reserved. So now there is no
219     explicit limit, but more stack is used.
220 ph10 189
221 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
222     syntax that is required for Windows, and which was going wrong for the
223     pcreposix and pcrecpp parts of the library. These were overlooked when this
224     problem was solved for the main library.
225 ph10 197
226 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
227     the size of patterns that contain repeated groups with explicit upper
228     limits. As the maximum quantifier is 65535, the maximum group length was
229     set at 30,000 so that the product of these two numbers did not overflow a
230     32-bit integer. However, it turns out that people want to use groups that
231     are longer than 30,000 bytes (though not repeat them that many times).
232     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
233     made it possible to implement the integer overflow checks in a much more
234     dynamic way, which I have now done. The artificial limitation on group
235     length has been removed - we now have only the limit on the total length of
236     the compiled pattern, which depends on the LINK_SIZE setting.
237 ph10 208
238     10. Fixed a bug in the documentation for get/copy named substring when
239     duplicate names are permitted. If none of the named substrings are set, the
240     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
241     empty string.
243     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
244     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
245     because the ] is interpreted as the first data character and the
246     terminating ] is not found. PCRE has been made compatible with Perl in this
247     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
248     cause memory overwriting.
250 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
251     string has been matched (to stop an infinite loop). It was not recognizing
252 ph10 208 a conditional subpattern that could match an empty string if that
253 ph10 206 subpattern was within another subpattern. For example, it looped when
254 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
255 ph10 206 condition was not nested. This bug has been fixed.
256 ph10 208
257 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
258     past the start of the subject in the presence of bytes with the top bit
259     set, for example "\x8aBCD".
260 ph10 211
261 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
262     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
263 ph10 200
264 ph10 211 14. Optimized (?!) to (*FAIL).
265 ph10 202
266 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
267     This restricts code points to be within the range 0 to 0x10FFFF, excluding
268     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
269     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
270     does: it's just the validity check that is more restrictive.
271 ph10 220
272     16. Inserted checks for integer overflows during escape sequence (backslash)
273     processing, and also fixed erroneous offset values for syntax errors during
274     backslash processing.
276 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
277 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
279 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
280     caused an overrun.
281 ph10 220
282     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
283     something other than just ASCII characters) inside a group that had an
284     unlimited repeat caused a loop at compile time (while checking to see
285     whether the group could match an empty string).
287 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
288     [\P{Any}] did so. (Error in the code for printing property names.)
289 ph10 210
290 ph10 220 21. An orphan \E inside a character class could cause a crash.
292     22. A repeated capturing bracket such as (A)? could cause a wild memory
293 ph10 218 reference during compilation.
294 ph10 220
295     23. There are several functions in pcre_compile() that scan along a compiled
296     expression for various reasons (e.g. to see if it's fixed length for look
297 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
298 ph10 220 present in the pattern. These operators have additional parameters compared
299     with \d, etc, and these were not being taken into account when moving along
300 ph10 218 the compiled data. Specifically:
301 ph10 220
302     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
303     length.
305     (b) An item such as \pL+ within a repeated group could cause crashes or
306 ph10 218 loops.
307 ph10 220
308 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
309 ph10 220 "reference to non-existent subpattern" error.
311 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
313 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
314 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
315 ph10 211
316 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
317 ph10 218
318 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
319 ph10 223 character were causing crashes (broken optimization).
320 ph10 227
321 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
322 ph10 227 \p or \P) caused a compile-time loop.
324 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
325     break. For example, the unstudied pattern [\r\n]A does not match the string
326     "\r\nA" because change 7.0/46 below moves the current point on by two
327     characters after failing to match at the start. However, the pattern \nA
328 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
329     the same is true. There doesn't seem any very clean way out of this, but
330     what I have chosen to do makes the common cases work: PCRE now takes note
331     of whether there can be an explicit match for \r or \n anywhere in the
332     pattern, and if so, 7.0/46 no longer applies. As part of this change,
333     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
334     pattern has explicit CR or LF references.
335 ph10 222
336 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
337 ph10 223
338 ph10 227
339 ph10 189 Version 7.2 19-Jun-07
340     ---------------------
342 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
343     which is apparently normally available under Windows.
344 ph10 159
345     2. Re-jig the pcregrep tests with different newline settings in an attempt
346     to make them independent of the local environment's newline setting.
347 ph10 157
348 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
349 ph10 165
350 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
351     was not 2, because the output contained actual offsets. The recent new
352 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
353     usable with all link sizes.
355 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
356     stack recursion. This gives a massive performance boost under BSD, but just
357 ph10 165 a small improvement under Linux. However, it saves one field in the frame
358 ph10 164 in all cases.
359 ph10 172
360 ph10 166 6. Added more features from the forthcoming Perl 5.10:
361 ph10 172
362 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
363     recursion call. It refers to the nth most recently opened parentheses.
364 ph10 172
365 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
366 ph10 172 to be opened parentheses.
368     (c) Conditions that refer to capturing parentheses can be specified
369 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
370 ph10 172
371 ph10 168 (d) \K resets the start of the current match so that everything before
372 ph10 172 is not part of it.
374 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
375 ph10 172
376 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
377 ph10 172 reference syntax.
378 ph10 182
379 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
380 ph10 182 alternative starts with the same number.
381 ph10 172
382 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
384 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
387     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
388     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
389 ph10 170 for detecting groups that can match an empty string.
390 ph10 159
391 ph10 172 9. A pattern with a very large number of alternatives (more than several
392     hundred) was running out of internal workspace during the pre-compile
393     phase, where pcre_compile() figures out how much memory will be needed. A
394     bit of new cunning has reduced the workspace needed for groups with
395     alternatives. The 1000-alternative test pattern now uses 12 bytes of
396     workspace instead of running out of the 4096 that are available.
397 ph10 182
398 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
399 ph10 172
400 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
401     The report of the bug said:
402 ph10 182
403 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
404     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
405 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
406 ph10 185
407 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
408 ph10 185 it matched the wrong number of bytes.
409 ph10 172
410 ph10 179
411 ph10 155 Version 7.1 24-Apr-07
412 ph10 98 ---------------------
414 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
415 ph10 122 that is more "standard", making use of automake and other Autotools. There
416 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
417     on this.
418 ph10 111
419     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
420     for recursive directory scanning broke on some systems because the files
421     are not scanned in any specific order and on different systems the order
422     was different. A call to "sort" has been inserted into RunGrepTest for the
423     approprate test as a short-term fix. In the longer term there may be an
424 ph10 100 alternative.
425 ph10 111
426 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
427 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
428     people do their own conversions for various reasons). The problems
429     concerned the use of low-level troff macros .br and .in. I have therefore
430     removed all such uses from the man pages (some were redundant, some could
431 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
432     HTML has been updated to handle .nf/.fi and to complain if it encounters
433     .br or .in.
434 ph10 111
435 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
436 ph10 123 arranged for config.h to be included in the distribution, with the name
437 ph10 111 config.h.generic, for the benefit of those who have to compile without
438     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
440     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
441     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
442 ph10 127 makevp.bat for the current PCRE, using the additional files
443 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
444 ph10 111
445     6. A Windows user reported a minor discrepancy with test 2, which turned out
446     to be caused by a trailing space on an input line that had got lost in his
447 ph10 102 copy. The trailing space was an accident, so I've just removed it.
448 ph10 111
449 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
450 ph10 111 that is needed.
452 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
453     as "const" (a) because they are and (b) because it helps the PHP
454     maintainers who have recently made a script to detect big data structures
455 ph10 111 in the php code that should be moved to the .rodata section. I remembered
456     to update Builducptable as well, so it won't revert if ucptable.h is ever
457 ph10 105 re-created.
458 ph10 111
459     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
460 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
461 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
462     support is not required. This saves 1.5-2K of code, which is important in
463 ph10 107 some applications.
464 ph10 111
465 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
466 ph10 111 so as not to refer to the tables, even though these functions will never be
467     called when UTF-8 support is disabled. Otherwise there are problems with a
468     shared library.
470 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
472     (a) It was defining its arguments as char * instead of void *.
474 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
475     a long time ago when I wrote it, but is no longer the case.
477 ph10 118 The emulated memove() is provided for those environments that have neither
478 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
479 ph10 118 is clearly not the case, as these two bugs were recently reported.
480 ph10 123
481 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
482 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
483     pages, and it removes trailing spaces from listed files. It also creates
484     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
485     case, it wraps all the #defines with #ifndefs. This script should be run
486 ph10 111 before "make dist".
487 ph10 123
488 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
489     with Unicode property support.
490 ph10 123
491     (a) For a maximizing quantifier, if the two different cases of the
492     character were of different lengths in their UTF-8 codings (there are
493     some cases like this - I found 11), and the matching function had to
494 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
495     were both the same length.
496 ph10 123
497     (b) When PCRE was configured to use the heap rather than the stack for
498     recursion during matching, it was not correctly preserving the data for
499     the other case of a UTF-8 character when checking ahead for a match
500     while processing a minimizing repeat. If the check also involved
501 ph10 115 matching a wide character, but failed, corruption could cause an
502     erroneous result when trying to check for a repeat of the original
503     character.
504 ph10 123
505 ph10 116 13. Some tidying changes to the testing mechanism:
506 ph10 98
507 ph10 116 (a) The RunTest script now detects the internal link size and whether there
508     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
509 ph10 123 values substituted by "configure". (The RunGrepTest script already did
510     this for UTF-8.) The configure.ac script no longer substitutes the
511     relevant variables.
513 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
514     with length and offset values. This means that the output is different
515     for different internal link sizes. Test 2 is skipped for link sizes
516     other than 2 because of this, bypassing the problem. Unfortunately,
517     there was also a test in test 3 (the locale tests) that used /B and
518 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
519     I have added a new /Z option to pcretest that replaces the length and
520     offset values with spaces. This is now used to make test 3 independent
521 ph10 122 of link size. (Test 2 will be tidied up later.)
522 ph10 123
523     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
524 ph10 122 segmentation fault instead of returning the appropriate error message.
525 ph10 134
526 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
527 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
528     This doesn't seem right; it now treats the CRLF combination as the line
529     ending, and so does not match in that case. It's only a pattern such as ^$
530     that would hit this one: something like ^ABC$ would have failed after \r
531     and then tried again after \r\n.
533 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
534 ph10 134 in an attempt to make files that differ only in their line terminators
535     compare equal. This works on Linux.
536 ph10 142
537 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
538     as it exited. This is now fixed, thanks to valgrind.
539 ph10 142
540 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
541 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
542     was because its rules for how to advance for /g after matching an empty
543 ph10 143 string at the end of a line did not allow for this case. They now check for
544     it specially.
545 ph10 150
546     20. pcretest is supposed to handle patterns and data of any length, by
547     extending its buffers when necessary. It was getting this wrong when the
548 ph10 147 buffer for a data line had to be extended.
549 ph10 150
550 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
551 ph10 150 CRLF as a newline sequence.
552 ph10 152
553 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
554 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
555     I have nevertheless tidied it up.
556 ph10 111
557 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
558 ph10 123
559 ph10 153 24. Added a man page for pcre-config.
560 ph10 152
561 ph10 153
562 nigel 93 Version 7.0 19-Dec-06
563     ---------------------
565     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
566     moving to gcc 4.1.1.
568     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
569     sys/time.h, which is documented as needed for this function. It doesn't
570     seem to matter on Linux, but it showed up on some releases of OS X.
572     3. It seems that there are systems where bytes whose values are greater than
573     127 match isprint() in the "C" locale. The "C" locale should be the
574     default when a C program starts up. In most systems, only ASCII printing
575     characters match isprint(). This difference caused the output from pcretest
576     to vary, making some of the tests fail. I have changed pcretest so that:
578     (a) When it is outputting text in the compiled version of a pattern, bytes
579     other than 32-126 are always shown as hex escapes.
581     (b) When it is outputting text that is a matched part of a subject string,
582     it does the same, unless a different locale has been set for the match
583     (using the /L modifier). In this case, it uses isprint() to decide.
585     4. Fixed a major bug that caused incorrect computation of the amount of memory
586     required for a compiled pattern when options that changed within the
587     pattern affected the logic of the preliminary scan that determines the
588     length. The relevant options are -x, and -i in UTF-8 mode. The result was
589     that the computed length was too small. The symptoms of this bug were
590     either the PCRE error "internal error: code overflow" from pcre_compile(),
591     or a glibc crash with a message such as "pcretest: free(): invalid next
592     size (fast)". Examples of patterns that provoked this bug (shown in
593     pcretest format) are:
595     /(?-x: )/x
596     /(?x)(?-x: \s*#\s*)/
597     /((?i)[\x{c0}])/8
598     /(?i:[\x{c0}])/8
600     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
601     is now done differently.
603     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
604     wrapper classes; (b) implement a new function in the C++ scanner that is
605     more efficient than the old way of doing things because it avoids levels of
606     recursion in the regex matching; (c) add a paragraph to the documentation
607     for the FullMatch() function.
609     6. The escape sequence \n was being treated as whatever was defined as
610     "newline". Not only was this contrary to the documentation, which states
611     that \n is character 10 (hex 0A), but it also went horribly wrong when
612     "newline" was defined as CRLF. This has been fixed.
614     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
615     was being set to -1 for the "end of line" case (supposedly a value that no
616     character can have). Though this value is never used (the check for end of
617     line is "zero bytes in current character"), it caused compiler complaints.
618     I've changed it to 0xffffffff.
620     8. In pcre_version.c, the version string was being built by a sequence of
621     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
622     string (as it is for production releases) called a macro with an empty
623     argument. The C standard says the result of this is undefined. The gcc
624     compiler treats it as an empty string (which was what was wanted) but it is
625     reported that Visual C gives an error. The source has been hacked around to
626     avoid this problem.
628     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
629     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
630     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
631     of them did).
633     10. Originally, pcretest opened its input and output without "b"; then I was
634     told that "b" was needed in some environments, so it was added for release
635     5.0 to both the input and output. (It makes no difference on Unix-like
636     systems.) Later I was told that it is wrong for the input on Windows. I've
637     now abstracted the modes into two macros, to make it easier to fiddle with
638     them, and removed "b" from the input mode under Windows.
640     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
642     12. Added -help and --help to pcretest as an official way of being reminded
643     of the options.
645     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
646     and pcrecpp.cc because they annoy compilers at high warning levels.
648     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
650     15. Fixed an occurrence of == in configure.ac that should have been = (shell
651     scripts are not C programs :-) and which was not noticed because it works
652     on Linux.
654     16. pcretest is supposed to handle any length of pattern and data line (as one
655     line or as a continued sequence of lines) by extending its input buffer if
656     necessary. This feature was broken for very long pattern lines, leading to
657     a string of junk being passed to pcre_compile() if the pattern was longer
658     than about 50K.
660     17. I have done a major re-factoring of the way pcre_compile() computes the
661     amount of memory needed for a compiled pattern. Previously, there was code
662     that made a preliminary scan of the pattern in order to do this. That was
663     OK when PCRE was new, but as the facilities have expanded, it has become
664     harder and harder to keep it in step with the real compile phase, and there
665     have been a number of bugs (see for example, 4 above). I have now found a
666     cunning way of running the real compile function in a "fake" mode that
667     enables it to compute how much memory it would need, while actually only
668     ever using a few hundred bytes of working memory and without too many
669     tests of the mode. This should make future maintenance and development
670     easier. A side effect of this work is that the limit of 200 on the nesting
671     depth of parentheses has been removed (though this was never a serious
672     limitation, I suspect). However, there is a downside: pcre_compile() now
673     runs more slowly than before (30% or more, depending on the pattern). I
674     hope this isn't a big issue. There is no effect on runtime performance.
676     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
677     newline (only possible for the last line of a file) and it was a
678     pattern that set a locale (followed by /Lsomething), pcretest crashed.
680     19. Added additional timing features to pcretest. (1) The -tm option now times
681     matching only, not compiling. (2) Both -t and -tm can be followed, as a
682     separate command line item, by a number that specifies the number of
683     repeats to use when timing. The default is 50000; this gives better
684     precision, but takes uncomfortably long for very large patterns.
686     20. Extended pcre_study() to be more clever in cases where a branch of a
687     subpattern has no definite first character. For example, (a*|b*)[cd] would
688     previously give no result from pcre_study(). Now it recognizes that the
689     first character must be a, b, c, or d.
691     21. There was an incorrect error "recursive call could loop indefinitely" if
692     a subpattern (or the entire pattern) that was being tested for matching an
693     empty string contained only one non-empty item after a nested subpattern.
694     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
695     incorrectly, because the \d was being skipped in the check.
697     22. The pcretest program now has a new pattern option /B and a command line
698     option -b, which is equivalent to adding /B to every pattern. This causes
699     it to show the compiled bytecode, without the additional information that
700     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
701     is the same as /B/I).
703     23. A new optimization is now able automatically to treat some sequences such
704     as a*b as a*+b. More specifically, if something simple (such as a character
705     or a simple class like \d) has an unlimited quantifier, and is followed by
706     something that cannot possibly match the quantified thing, the quantifier
707     is automatically "possessified".
709     24. A recursive reference to a subpattern whose number was greater than 39
710     went wrong under certain circumstances in UTF-8 mode. This bug could also
711     have affected the operation of pcre_study().
713     25. Realized that a little bit of performance could be had by replacing
714     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
716     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
718     27. Possessive quantifiers such as a++ were previously implemented by turning
719     them into atomic groups such as ($>a+). Now they have their own opcodes,
720     which improves performance. This includes the automatically created ones
721     from 23 above.
723     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
724     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
725     the first matched character to be a colon. This applied both to named and
726     numbered groups.
728     29. The ucpinternal.h header file was missing its idempotency #ifdef.
730     30. I was sent a "project" file called libpcre.a.dev which I understand makes
731     building PCRE on Windows easier, so I have included it in the distribution.
733     31. There is now a check in pcretest against a ridiculously large number being
734     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
735     loop, the loop is abandoned.
737     32. Forward references to subpatterns in conditions such as (?(2)...) where
738     subpattern 2 is defined later cause pcre_compile() to search forwards in
739     the pattern for the relevant set of parentheses. This search went wrong
740     when there were unescaped parentheses in a character class, parentheses
741     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
743     33. "Subroutine" calls and backreferences were previously restricted to
744     referencing subpatterns earlier in the regex. This restriction has now
745     been removed.
747     34. Added a number of extra features that are going to be in Perl 5.10. On the
748     whole, these are just syntactic alternatives for features that PCRE had
749     previously implemented using the Python syntax or my own invention. The
750     other formats are all retained for compatibility.
752     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
753     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
754     also .NET compatible.
756     (b) A recursion or subroutine call to a named group can now be defined as
757     (?&name) as well as (?P>name).
759     (c) A backreference to a named group can now be defined as \k<name> or
760     \k'name' as well as (?P=name). The new forms, as well as being in Perl
761     5.10, are also .NET compatible.
763     (d) A conditional reference to a named group can now use the syntax
764     (?(<name>) or (?('name') as well as (?(name).
766     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
767     groups (named and numbered) that are never evaluated inline, but can be
768     called as "subroutines" from elsewhere. In effect, the DEFINE condition
769     is always false. There may be only one alternative in such a group.
771     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
772     as the simple (?(R). The condition is true only if the most recent
773     recursion is that of the given number or name. It does not search out
774     through the entire recursion stack.
776     (g) The escape \gN or \g{N} has been added, where N is a positive or
777     negative number, specifying an absolute or relative reference.
779     35. Tidied to get rid of some further signed/unsigned compiler warnings and
780     some "unreachable code" warnings.
782     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
783     things, this adds five new scripts.
785     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
786     There were also incompatibilities regarding the handling of \Q..\E inside
787     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
788     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
790     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
791     matches an empty string, and forcibly breaks the loop. There were bugs in
792     this code in non-simple cases. For a pattern such as ^(a()*)* matched
793     against aaaa the result was just "a" rather than "aaaa", for example. Two
794     separate and independent bugs (that affected different cases) have been
795     fixed.
797     39. Refactored the code to abolish the use of different opcodes for small
798     capturing bracket numbers. This is a tidy that I avoided doing when I
799     removed the limit on the number of capturing brackets for 3.5 back in 2001.
800     The new approach is not only tidier, it makes it possible to reduce the
801     memory needed to fix the previous bug (38).
803     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
804     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
805     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
806     mode.
808     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
809     report.
811     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
812     copy construction and assignment in the C++ wrapper.
814     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
815     couple of bugs that could have given wrong results in the "--newline=crlf"
816     case.
818     44. Added a number of casts and did some reorganization of signed/unsigned int
819     variables following suggestions from Dair Grant. Also renamed the variable
820     "this" as "item" because it is a C++ keyword.
822     45. Arranged for dftables to add
824     #include "pcre_internal.h"
826     to pcre_chartables.c because without it, gcc 4.x may remove the array
827     definition from the final binary if PCRE is built into a static library and
828     dead code stripping is activated.
830     46. For an unanchored pattern, if a match attempt fails at the start of a
831     newline sequence, and the newline setting is CRLF or ANY, and the next two
832     characters are CRLF, advance by two characters instead of one.
835 nigel 91 Version 6.7 04-Jul-06
836     ---------------------
838     1. In order to handle tests when input lines are enormously long, pcretest has
839     been re-factored so that it automatically extends its buffers when
840     necessary. The code is crude, but this _is_ just a test program. The
841     default size has been increased from 32K to 50K.
843     2. The code in pcre_study() was using the value of the re argument before
844     testing it for NULL. (Of course, in any sensible call of the function, it
845     won't be NULL.)
847     3. The memmove() emulation function in pcre_internal.h, which is used on
848     systems that lack both memmove() and bcopy() - that is, hardly ever -
849     was missing a "static" storage class specifier.
851     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
852     containing an extended class (one that cannot be represented by a bitmap
853     because it contains high-valued characters or Unicode property items, e.g.
854     [\pZ]). Almost always one would set UTF-8 mode when processing such a
855     pattern, but PCRE should not loop if you do not (it no longer does).
856     [Detail: two cases were found: (a) a repeated subpattern containing an
857     extended class; (b) a recursive reference to a subpattern that followed a
858     previous extended class. It wasn't skipping over the extended class
859     correctly when UTF-8 mode was not set.]
861     5. A negated single-character class was not being recognized as fixed-length
862     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
863     compile error "lookbehind assertion is not fixed length".
865     6. The RunPerlTest auxiliary script was showing an unexpected difference
866     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
867     write a Perl script that can interpret lines of an input file either as
868     byte characters or as UTF-8, which is what "perltest" was being required to
869     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
870     can't do is switch easily at run time between having the "use utf8;" pragma
871     or not. In the end, I fudged it by using the RunPerlTest script to insert
872     "use utf8;" explicitly for the UTF-8 tests.
874     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
875     the end of the subject string, contrary to the documentation and to what
876     Perl does. This was true of both matching functions. Now it matches only at
877     the start of the subject and immediately after *internal* newlines.
879     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
880     a pointer to an int instead of a pointer to an unsigned long int. This
881     caused problems on 64-bit systems.
883     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
884     instance of the 'standard' template library not being so standard".
886     10. There was no check on the number of named subpatterns nor the maximum
887     length of a subpattern name. The product of these values is used to compute
888     the size of the memory block for a compiled pattern. By supplying a very
889     long subpattern name and a large number of named subpatterns, the size
890     computation could be caused to overflow. This is now prevented by limiting
891     the length of names to 32 characters, and the number of named subpatterns
892     to 10,000.
894     11. Subpatterns that are repeated with specific counts have to be replicated in
895     the compiled pattern. The size of memory for this was computed from the
896     length of the subpattern and the repeat count. The latter is limited to
897     65535, but there was no limit on the former, meaning that integer overflow
898     could in principle occur. The compiled length of a repeated subpattern is
899     now limited to 30,000 bytes in order to prevent this.
901     12. Added the optional facility to have named substrings with the same name.
903     13. Added the ability to use a named substring as a condition, using the
904     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
905     are numbers (not recommended). Forward references are permitted.
907     14. Added forward references in named backreferences (if you see what I mean).
909     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
910     pattern could run off the end of the subject. For example, the pattern
911     "(?s)(.{1,5})"8 did this with the subject "ab".
913     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
914     PCRE_CASELESS was set when matching characters that were quantified with ?
915     or *.
917     17. A character class other than a single negated character that had a minimum
918     but no maximum quantifier - for example [ab]{6,} - was not handled
919     correctly by pce_dfa_exec(). It would match only one character.
921     18. A valid (though odd) pattern that looked like a POSIX character
922     class but used an invalid character after [ (for example [[,abc,]]) caused
923     pcre_compile() to give the error "Failed: internal error: code overflow" or
924     in some cases to crash with a glibc free() error. This could even happen if
925     the pattern terminated after [[ but there just happened to be a sequence of
926     letters, a binary zero, and a closing ] in the memory that followed.
928     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
929     over the years. Originally (before any Unicode support), just the bottom 8
930     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
931     output from "man perlunicode" includes this:
933     The regular expression compiler produces polymorphic opcodes. That
934     is, the pattern adapts to the data and automatically switches to
935     the Unicode character scheme when presented with Unicode data--or
936     instead uses a traditional byte scheme when presented with byte
937     data.
939     Sadly, a wide octal escape does not cause a switch, and in a string with
940     no other multibyte characters, these octal escapes are treated as before.
941     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
942     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
943     Unicode string.
945     I have not perpetrated such confusion in PCRE. Up till now, it took just
946     the bottom 8 bits, as in old Perl. I have now made octal escapes with
947     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
948     translate to the appropriate multibyte character.
950     29. Applied some refactoring to reduce the number of warnings from Microsoft
951     and Borland compilers. This has included removing the fudge introduced
952     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
953     a warning about an unused variable.
955     21. PCRE has not included VT (character 0x0b) in the set of whitespace
956     characters since release 4.0, because Perl (from release 5.004) does not.
957     [Or at least, is documented not to: some releases seem to be in conflict
958     with the documentation.] However, when a pattern was studied with
959     pcre_study() and all its branches started with \s, PCRE still included VT
960     as a possible starting character. Of course, this did no harm; it just
961     caused an unnecessary match attempt.
963     22. Removed a now-redundant internal flag bit that recorded the fact that case
964     dependency changed within the pattern. This was once needed for "required
965     byte" processing, but is no longer used. This recovers a now-scarce options
966     bit. Also moved the least significant internal flag bit to the most-
967     significant bit of the word, which was not previously used (hangover from
968     the days when it was an int rather than a uint) to free up another bit for
969     the future.
971     23. Added support for CRLF line endings as well as CR and LF. As well as the
972     default being selectable at build time, it can now be changed at runtime
973     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
974     specify that it is scanning data with non-default line endings.
976     24. Changed the definition of CXXLINK to make it agree with the definition of
977     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
979     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
980     recursions. This makes a big different to stack usage for some patterns.
982     26. If a subpattern containing a named recursion or subroutine reference such
983     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
984     the space required for the compiled pattern went wrong and gave too small a
985     value. Depending on the environment, this could lead to "Failed: internal
986     error: code overflow at offset 49" or "glibc detected double free or
987     corruption" errors.
989     27. Applied patches from Google (a) to support the new newline modes and (b) to
990     advance over multibyte UTF-8 characters in GlobalReplace.
992     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
993     difference for some implementation of PCRE in some Windows version.
995     29. Added some extra testing facilities to pcretest:
997     \q<number> in a data line sets the "match limit" value
998     \Q<number> in a data line sets the "match recursion limt" value
999     -S <number> sets the stack size, where <number> is in megabytes
1001     The -S option isn't available for Windows.
1004 nigel 89 Version 6.6 06-Feb-06
1005     ---------------------
1007     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1008     in pcreposix.h. I have copied the definition from pcre.h.
1010     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1011     because pcre.h is no longer a built file.
1013     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1014     not normally included in the compiled code.
1017 nigel 87 Version 6.5 01-Feb-06
1018     ---------------------
1020     1. When using the partial match feature with pcre_dfa_exec(), it was not
1021     anchoring the second and subsequent partial matches at the new starting
1022     point. This could lead to incorrect results. For example, with the pattern
1023     /1234/, partially matching against "123" and then "a4" gave a match.
1025     2. Changes to pcregrep:
1027     (a) All non-match returns from pcre_exec() were being treated as failures
1028     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1029     error message is output. Some extra information is given for the
1031     probably the only errors that are likely to be caused by users (by
1032     specifying a regex that has nested indefinite repeats, for instance).
1033     If there are more than 20 of these errors, pcregrep is abandoned.
1035     (b) A binary zero was treated as data while matching, but terminated the
1036     output line if it was written out. This has been fixed: binary zeroes
1037     are now no different to any other data bytes.
1039     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1040     used to set a locale for matching. The --locale=xxxx long option has
1041     been added (no short equivalent) to specify a locale explicitly on the
1042     pcregrep command, overriding the environment variables.
1044     (d) When -B was used with -n, some line numbers in the output were one less
1045     than they should have been.
1047     (e) Added the -o (--only-matching) option.
1049     (f) If -A or -C was used with -c (count only), some lines of context were
1050     accidentally printed for the final match.
1052     (g) Added the -H (--with-filename) option.
1054     (h) The combination of options -rh failed to suppress file names for files
1055     that were found from directory arguments.
1057     (i) Added the -D (--devices) and -d (--directories) options.
1059     (j) Added the -F (--fixed-strings) option.
1061     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1063     (l) Added the --colo(u)r option.
1065     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1066     is not present by default.
1068     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1069     items such as (?R) or (?1), when the recursion could match a number of
1070     alternatives. If it matched one of the alternatives, but subsequently,
1071     outside the recursion, there was a failure, the code tried to back up into
1072     the recursion. However, because of the way PCRE is implemented, this is not
1073     possible, and the result was an incorrect result from the match.
1075     In order to prevent this happening, the specification of recursion has
1076     been changed so that all such subpatterns are automatically treated as
1077     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1079     4. I had overlooked the fact that, in some locales, there are characters for
1080     which isalpha() is true but neither isupper() nor islower() are true. In
1081     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1082     and ordfeminine) are like this. This affected the treatment of \w and \W
1083     when they appeared in character classes, but not when they appeared outside
1084     a character class. The bit map for "word" characters is now created
1085     separately from the results of isalnum() instead of just taking it from the
1086     upper, lower, and digit maps. (Plus the underscore character, of course.)
1088     5. The above bug also affected the handling of POSIX character classes such as
1089     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1090     permanent tables. Instead, the bit maps for such a class were previously
1091     created as the appropriate unions of the upper, lower, and digit bitmaps.
1092     Now they are created by subtraction from the [[:word:]] class, which has
1093     its own bitmap.
1095     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1096     It is created by subtracting the vertical space characters (\x09, \x0a,
1097     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1098     subtraction was done in the overall bitmap for a character class, meaning
1099     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1100     be recognized. This bug has been fixed.
1102     7. Patches from the folks at Google:
1104     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1105     real life, but is still worth protecting against".
1107     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1108     regular expressions".
1110     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1111     have it.
1113     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1114     "configure" and the latter not, in order to fix a problem somebody had
1115     with compiling the Arg class on HP-UX.
1117     (e) Improve the error-handling of the C++ wrapper a little bit.
1119     (f) New tests for checking recursion limiting.
1121     8. The pcre_memmove() function, which is used only if the environment does not
1122     have a standard memmove() function (and is therefore rarely compiled),
1123     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1124     returning a result (though PCRE never actually uses the result).
1126     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1127     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1128     returned instead of calling malloc() with an overflowing number that would
1129     most likely cause subsequent chaos.
1131     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1133     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1134     with this option is matched, the nmatch and pmatch options of regexec() are
1135     ignored.
1137     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1138     provided in case anyone wants to the the POSIX interface with UTF-8
1139     strings.
1141     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1142     C++ linking (needed for some HP-UX environments).
1144     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1145     (unused parameter) and in the pcre_printint() function (omitted "default"
1146     switch label when the default is to do nothing).
1148     15. Added some code to make it possible, when PCRE is compiled as a C++
1149     library, to replace subject pointers for pcre_exec() with a smart pointer
1150     class, thus making it possible to process discontinuous strings.
1152     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1153     much the same function. They were added by different people who were trying
1154     to make PCRE easy to compile on non-Unix systems. It has been suggested
1155     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1156     for compiling on Windows systems. I have therefore replaced it with
1157     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1158     defaults to "extern" for C or "extern C" for C++, which works fine on
1159     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1160     SCOPE with something explicit in config.h. In addition:
1162     (a) pcreposix.h still had just "extern" instead of either of these macros;
1163     I have replaced it with PCRE_DATA_SCOPE.
1165     (b) Functions such as _pcre_xclass(), which are internal to the library,
1166     but external in the C sense, all had PCRE_EXPORT in their definitions.
1167     This is apparently wrong for the Windows case, so I have removed it.
1168     (It makes no difference on Unix-like systems.)
1170     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1171     of recursive calls to match(). This is different to MATCH_LIMIT because
1172     that limits the total number of calls to match(), not all of which increase
1173     the depth of recursion. Limiting the recursion depth limits the amount of
1174     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1175     when PCRE is compiled, and changed at run time. A patch from Google adds
1176     this functionality to the C++ interface.
1178     18. Changes to the handling of Unicode character properties:
1180     (a) Updated the table to Unicode 4.1.0.
1182     (b) Recognize characters that are not in the table as "Cn" (undefined).
1184     (c) I revised the way the table is implemented to a much improved format
1185     which includes recognition of ranges. It now supports the ranges that
1186     are defined in UnicodeData.txt, and it also amalgamates other
1187     characters into ranges. This has reduced the number of entries in the
1188     table from around 16,000 to around 3,000, thus reducing its size
1189     considerably. I realized I did not need to use a tree structure after
1190     all - a binary chop search is just as efficient. Having reduced the
1191     number of entries, I extended their size from 6 bytes to 8 bytes to
1192     allow for more data.
1194     (d) Added support for Unicode script names via properties such as \p{Han}.
1196     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1197     matching that character.
1199     20. When matching a repeated Unicode property with a minimum greater than zero,
1200     (for example \pL{2,}), PCRE could look past the end of the subject if it
1201     reached it while seeking the minimum number of characters. This could
1202     happen only if some of the characters were more than one byte long, because
1203     there is a check for at least the minimum number of bytes.
1205     21. Refactored the implementation of \p and \P so as to be more general, to
1206     allow for more different types of property in future. This has changed the
1207     compiled form incompatibly. Anybody with saved compiled patterns that use
1208     \p or \P will have to recompile them.
1210     22. Added "Any" and "L&" to the supported property types.
1212     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1213     but give a compile time error if the value is greater than 0xff.
1215     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1216     accidentally not being installed or uninstalled.
1218     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1219     made were to insert the current release number. This seemed silly, because
1220     it made things harder for people building PCRE on systems that don't run
1221     "configure". I have turned pcre.h into a distributed file, no longer built
1222     by "configure", with the version identification directly included. There is
1223     no longer a pcre.h.in file.
1225     However, this change necessitated a change to the pcre-config script as
1226     well. It is built from pcre-config.in, and one of the substitutions was the
1227     release number. I have updated configure.ac so that ./configure now finds
1228     the release number by grepping pcre.h.
1230     26. Added the ability to run the tests under valgrind.
1233 nigel 85 Version 6.4 05-Sep-05
1234     ---------------------
1236     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1237     "--" to be printed when multiple files were scanned, even when none of the
1238     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1239     consider it to be a bug, and have restored the previous behaviour.
1241     2. A couple of code tidies to get rid of compiler warnings.
1243     3. The pcretest program used to cheat by referring to symbols in the library
1244     whose names begin with _pcre_. These are internal symbols that are not
1245     really supposed to be visible externally, and in some environments it is
1246     possible to suppress them. The cheating is now confined to including
1247     certain files from the library's source, which is a bit cleaner.
1249     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1250     file's purpose clearer.
1252     5. Reorganized pcre_ucp_findchar().
1255 nigel 83 Version 6.3 15-Aug-05
1256     ---------------------
1258     1. The file libpcre.pc.in did not have general read permission in the tarball.
1260     2. There were some problems when building without C++ support:
1262     (a) If C++ support was not built, "make install" and "make test" still
1263     tried to test it.
1265     (b) There were problems when the value of CXX was explicitly set. Some
1266     changes have been made to try to fix these, and ...
1268     (c) --disable-cpp can now be used to explicitly disable C++ support.
1270     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1271     backslash in a target when C++ was disabled. This confuses some
1272     versions of "make", apparently. Using an intermediate variable solves
1273     this. (Same for CPP_LOBJ.)
1275     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1276     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1277     necessary on certain architectures.
1279     4. Added a setting of -export-symbols-regex to the link command to remove
1280     those symbols that are exported in the C sense, but actually are local
1281     within the library, and not documented. Their names all begin with
1282     "_pcre_". This is not a perfect job, because (a) we have to except some
1283     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1284     available (and never for static libraries). I have made a note to try to
1285     find a way round (a) in the future.
1288 nigel 81 Version 6.2 01-Aug-05
1289     ---------------------
1291     1. There was no test for integer overflow of quantifier values. A construction
1292     such as {1111111111111111} would give undefined results. What is worse, if
1293     a minimum quantifier for a parenthesized subpattern overflowed and became
1294     negative, the calculation of the memory size went wrong. This could have
1295     led to memory overwriting.
1297     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1299     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1300     operating environments where this matters.
1302     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1303     PCRE options from within the C++ wrapper.
1305     5. Named capturing subpatterns were not being correctly counted when a pattern
1306     was compiled. This caused two problems: (a) If there were more than 100
1307     such subpatterns, the calculation of the memory needed for the whole
1308     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1309     back references of the form \12, where the number was greater than 9, were
1310     not recognized as back references, even though there were sufficient
1311     previous subpatterns.
1313     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1314     versions of gcc, e.g. 2.95.4.
1317 nigel 79 Version 6.1 21-Jun-05
1318     ---------------------
1320     1. There was one reference to the variable "posix" in pcretest.c that was not
1321     surrounded by "#if !defined NOPOSIX".
1323     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1324     the cross-check on the old pcre_info() function, for the benefit of the
1325     cut-down version of PCRE that is currently imported into Exim.
1327     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1328     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1329     patterns that start (?i) but I don't think that matters. The use of (?i) is
1330     just an example; this all applies to the other options as well.
1332     4. Since libtool seems to echo the compile commands it is issuing, the output
1333     from "make" can be reduced a bit by putting "@" in front of each libtool
1334     compile command.
1336     5. Patch from the folks at Google for configure.in to be a bit more thorough
1337     in checking for a suitable C++ installation before trying to compile the
1338     C++ stuff. This should fix a reported problem when a compiler was present,
1339     but no suitable headers.
1341     6. The man pages all had just "PCRE" as their title. I have changed them to
1342     be the relevant file name. I have also arranged that these names are
1343     retained in the file doc/pcre.txt, which is a concatenation in text format
1344     of all the man pages except the little individual ones for each function.
1346     7. The NON-UNIX-USE file had not been updated for the different set of source
1347     files that come with release 6. I also added a few comments about the C++
1348     wrapper.
1351 nigel 77 Version 6.0 07-Jun-05
1352     ---------------------
1354     1. Some minor internal re-organization to help with my DFA experiments.
1356     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1357     didn't matter for the library itself when fully configured, but did matter
1358     when compiling without UCP support, or within Exim, where the ucp files are
1359     not imported.
1361     3. Refactoring of the library code to split up the various functions into
1362     different source modules. The addition of the new DFA matching code (see
1363     below) to a single monolithic source would have made it really too
1364     unwieldy, quite apart from causing all the code to be include in a
1365     statically linked application, when only some functions are used. This is
1366     relevant even without the DFA addition now that patterns can be compiled in
1367     one application and matched in another.
1369     The downside of splitting up is that there have to be some external
1370     functions and data tables that are used internally in different modules of
1371     the library but which are not part of the API. These have all had their
1372     names changed to start with "_pcre_" so that they are unlikely to clash
1373     with other external names.
1375     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1376     a different (DFA) algorithm. Although it is slower than the original
1377     function, it does have some advantages for certain types of matching
1378     problem.
1380     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1381     including restarting after a partial match.
1383     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1384     defined when compiling for Windows was sent to me. I have put it into the
1385     code, though I have no means of testing or verifying it.
1387     7. Added the pcre_refcount() auxiliary function.
1389     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1390     match before or at the first newline in the subject string. In pcretest,
1391     the /f option on a pattern can be used to set this.
1393     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1394     would behave wrongly. This has been present in PCRE since release 4.0.
1396     10. A number of changes to the pcregrep command:
1398     (a) Refactored how -x works; insert ^(...)$ instead of setting
1399     PCRE_ANCHORED and checking the length, in preparation for adding
1400     something similar for -w.
1402     (b) Added the -w (match as a word) option.
1404     (c) Refactored the way lines are read and buffered so as to have more
1405     than one at a time available.
1407     (d) Implemented a pcregrep test script.
1409     (e) Added the -M (multiline match) option. This allows patterns to match
1410     over several lines of the subject. The buffering ensures that at least
1411     8K, or the rest of the document (whichever is the shorter) is available
1412     for matching (and similarly the previous 8K for lookbehind assertions).
1414     (f) Changed the --help output so that it now says
1416     -w, --word-regex(p)
1418     instead of two lines, one with "regex" and the other with "regexp"
1419     because that confused at least one person since the short forms are the
1420     same. (This required a bit of code, as the output is generated
1421     automatically from a table. It wasn't just a text change.)
1423     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1424     option but starts with a hyphen. Could be a pattern or a path name
1425     starting with a hyphen, for instance.
1427     (h) "-" can be given as a file name to represent stdin.
1429     (i) When file names are being printed, "(standard input)" is used for
1430     the standard input, for compatibility with GNU grep. Previously
1431     "<stdin>" was used.
1433     (j) The option --label=xxx can be used to supply a name to be used for
1434     stdin when file names are being printed. There is no short form.
1436     (k) Re-factored the options decoding logic because we are going to add
1437     two more options that take data. Such options can now be given in four
1438     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1440     (l) Added the -A, -B, and -C options for requesting that lines of context
1441     around matches be printed.
1443     (m) Added the -L option to print the names of files that do not contain
1444     any matching lines, that is, the complement of -l.
1446     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1447     continue to scan other files.
1449     (o) The -s option was incorrectly implemented. For compatibility with other
1450     greps, it now suppresses the error message for a non-existent or non-
1451     accessible file (but not the return code). There is a new option called
1452     -q that suppresses the output of matching lines, which was what -s was
1453     previously doing.
1455     (p) Added --include and --exclude options to specify files for inclusion
1456     and exclusion when recursing.
1458     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1459     Hopefully, it now does.
1461     12. Missing cast in pcre_study().
1463     13. Added an "uninstall" target to the makefile.
1465     14. Replaced "extern" in the function prototypes in Makefile.in with
1466     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1467     world, but is set differently for Windows.
1469     15. Added a second compiling function called pcre_compile2(). The only
1470     difference is that it has an extra argument, which is a pointer to an
1471     integer error code. When there is a compile-time failure, this is set
1472     non-zero, in addition to the error test pointer being set to point to an
1473     error message. The new argument may be NULL if no error number is required
1474     (but then you may as well call pcre_compile(), which is now just a
1475     wrapper). This facility is provided because some applications need a
1476     numeric error indication, but it has also enabled me to tidy up the way
1477     compile-time errors are handled in the POSIX wrapper.
1479     16. Added VPATH=.libs to the makefile; this should help when building with one
1480     prefix path and installing with another. (Or so I'm told by someone who
1481     knows more about this stuff than I do.)
1483     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1484     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1485     match everything, including newlines. This is not POSIX-compatible, but
1486     somebody wanted the feature. From pcretest it can be activated by using
1487     both the P and the s flags.
1489     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1491     19. libpcre.pc was being incorrectly installed as executable.
1493     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1494     it now also looks for '\r' so that it will work unmodified on Windows.
1496     21. Added Google's contributed C++ wrapper to the distribution.
1498     22. Added some untidy missing memory free() calls in pcretest, to keep
1499     Electric Fence happy when testing.
1503 nigel 75 Version 5.0 13-Sep-04
1504     ---------------------
1506     1. Internal change: literal characters are no longer packed up into items
1507     containing multiple characters in a single byte-string. Each character
1508     is now matched using a separate opcode. However, there may be more than one
1509     byte in the character in UTF-8 mode.
1511     2. The pcre_callout_block structure has two new fields: pattern_position and
1512     next_item_length. These contain the offset in the pattern to the next match
1513     item, and its length, respectively.
1515     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1516     insertion of callouts before each pattern item. Added the /C option to
1517     pcretest to make use of this.
1519     4. On the advice of a Windows user, the lines
1521     #if defined(_WIN32) || defined(WIN32)
1522     _setmode( _fileno( stdout ), 0x8000 );
1523     #endif /* defined(_WIN32) || defined(WIN32) */
1525     have been added to the source of pcretest. This apparently does useful
1526     magic in relation to line terminators.
1528     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1529     for the benefit of those environments where the "b" makes a difference.
1531     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1532     to know about it. I have put a hack into configure.in that adds in code
1533     to set GCC=yes if CC=icc. This seems to end up at a point in the
1534     generated configure script that is early enough to affect the setting of
1535     compiler options, which is what is needed, but I have no means of testing
1536     whether it really works. (The user who reported this had patched the
1537     generated configure script, which of course I cannot do.)
1539     LATER: After change 22 below (new libtool files), the configure script
1540     seems to know about icc (and also ecc). Therefore, I have commented out
1541     this hack in configure.in.
1543     7. Added support for pkg-config (2 patches were sent in).
1545     8. Negated POSIX character classes that used a combination of internal tables
1546     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1547     [[:^ascii]]. Typically, they would match almost any characters. The other
1548     POSIX classes were not broken in this way.
1550     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1551     to find the match, as PCRE was deluded into thinking that the match had to
1552     start at the start point or following a newline. The same bug applied to
1553     patterns with negative forward assertions or any backward assertions
1554     preceding ".*" at the start, unless the pattern required a fixed first
1555     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1557     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1558     starting at the last subject character, bytes beyond the end of the subject
1559     string were read.
1561     11. Renamed the variable "class" as "classbits" to make life easier for C++
1562     users. (Previously there was a macro definition, but it apparently wasn't
1563     enough.)
1565     12. Added the new field "tables" to the extra data so that tables can be passed
1566     in at exec time, or the internal tables can be re-selected. This allows
1567     a compiled regex to be saved and re-used at a later time by a different
1568     program that might have everything at different addresses.
1570     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1571     -R library as well as a -L library.
1573     14. The debugging options of pcretest (-d on the command line or D on a
1574     pattern) showed incorrect output for anything following an extended class
1575     that contained multibyte characters and which was followed by a quantifier.
1577     15. Added optional support for general category Unicode character properties
1578     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1579     support. It adds about 90K to the size of the library. The meanings of the
1580     inbuilt class escapes such as \d and \s have NOT been changed.
1582     16. Updated pcredemo.c to include calls to free() to release the memory for the
1583     compiled pattern.
1585     17. The generated file chartables.c was being created in the source directory
1586     instead of in the building directory. This caused the build to fail if the
1587     source directory was different from the building directory, and was
1588     read-only.
1590     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1591     file. No doubt somebody will tell me if they don't make sense... Also added
1592     Dan Mooney's comments about building on OpenVMS.
1594     19. Added support for partial matching via the PCRE_PARTIAL option for
1595     pcre_exec() and the \P data escape in pcretest.
1597     20. Extended pcretest with 3 new pattern features:
1599     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1600     write the compiled pattern to the file whose name is "rest-of-line".
1601     This is a straight binary dump of the data, with the saved pointer to
1602     the character tables forced to be NULL. The study data, if any, is
1603     written too. After writing, pcretest reads a new pattern.
1605     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1606     compiled pattern from the given file. There must not be any
1607     occurrences of "<" in the file name (pretty unlikely); if there are,
1608     pcretest will instead treat the initial "<" as a pattern delimiter.
1609     After reading in the pattern, pcretest goes on to read data lines as
1610     usual.
1612     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1613     and 16-bit fields in a compiled pattern, to simulate a pattern that
1614     was compiled on a host of opposite endianness.
1616     21. The pcre-exec() function can now cope with patterns that were compiled on
1617     hosts of opposite endianness, with this restriction:
1619     As for any compiled expression that is saved and used later, the tables
1620     pointer field cannot be preserved; the extra_data field in the arguments
1621     to pcre_exec() should be used to pass in a tables address if a value
1622     other than the default internal tables were used at compile time.
1624     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1625     now diagnosed as an error. Previously, most of the time, a negative number
1626     would have been treated as zero, but if in addition "ovector" was passed as
1627     NULL, a crash could occur.
1629     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1630     new versions from the libtool 1.5 distribution (the last one is a copy of
1631     a file called libtool.m4). This seems to have fixed the need to patch
1632     "configure" to support Darwin 1.3 (which I used to do). However, I still
1633     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1634     workstation).
1636     24. Changed the PCRE licence to be the more standard "BSD" licence.
1639 nigel 73 Version 4.5 01-Dec-03
1640     ---------------------
1642     1. There has been some re-arrangement of the code for the match() function so
1643     that it can be compiled in a version that does not call itself recursively.
1644     Instead, it keeps those local variables that need separate instances for
1645     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1646     needs to "recurse". Keeping track of where control must go is done by means
1647     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1648     hide most of the details from the main code, and operates only if
1649     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1650     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1651     operating.
1653     To make it easier for callers to provide specially tailored get/free
1654     functions for this usage, two new functions, pcre_stack_malloc, and
1655     pcre_stack_free, are used. They are always called in strict stacking order,
1656     and the size of block requested is always the same.
1658     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1659     PCRE has been compiled to use the stack or the heap for recursion. The
1660     -C option of pcretest uses this to show which version is compiled.
1662     A new data escape \S, is added to pcretest; it causes the amounts of store
1663     obtained and freed by both kinds of malloc/free at match time to be added
1664     to the output.
1666     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1667     what's available on my current Linux desktop machine.
1669     3. When matching a UTF-8 string, the test for a valid string at the start has
1670     been extended. If start_offset is not zero, PCRE now checks that it points
1671     to a byte that is the start of a UTF-8 character. If not, it returns
1672     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1673     this is necessary because there may be backward assertions in the pattern.
1674     When matching the same subject several times, it may save resources to use
1675     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1677     4. The code for checking the validity of UTF-8 strings has been tightened so
1678     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1679     containing "overlong sequences".
1681     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1682     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1683     should have been "&", but it just so happened that all the cases this let
1684     through by mistake were picked up later in the function.
1686     6. I had used a variable called "isblank" - this is a C99 function, causing
1687     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1689     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1690     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1691     so the version is shown; (c) stop "make test" echoing "./RunTest".
1693     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1695     9. The prototype for memmove() for systems that don't have it was using
1696     size_t, but the inclusion of the header that defines size_t was later. I've
1697     moved the #includes for the C headers earlier to avoid this.
1699     10. Added some adjustments to the code to make it easier to compiler on certain
1700     special systems:
1702     (a) Some "const" qualifiers were missing.
1703     (b) Added the macro EXPORT before all exported functions; by default this
1704     is defined to be empty.
1705     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1706     that it reads its output file name as an argument instead of writing
1707     to the standard output and assuming this can be redirected.
1709     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1710     class containing characters with values greater than 255, PCRE compilation
1711     went into a loop.
1713     12. A recursive reference to a subpattern that was within another subpattern
1714     that had a minimum quantifier of zero caused PCRE to crash. For example,
1715     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1716     recursion. If the recursively-called subpattern itself had a zero repeat,
1717     that was OK.
1719     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1720     buffer into which it was copied (for escape processing) was still set at
1721     1024, so long lines caused crashes.
1723     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1724     "internal error: code overflow...". This applied to any character class
1725     that was followed by a possessive quantifier.
1727     15. Modified the Makefile to add libpcre.la as a prerequisite for
1728     libpcreposix.la because I was told this is needed for a parallel build to
1729     work.
1731     16. If a pattern that contained .* following optional items at the start was
1732     studied, the wrong optimizing data was generated, leading to matching
1733     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1734     matching string must start with a or b or c. The correct conclusion for
1735     this pattern is that a match can start with any character.
1738 nigel 71 Version 4.4 13-Aug-03
1739     ---------------------
1741     1. In UTF-8 mode, a character class containing characters with values between
1742     127 and 255 was not handled correctly if the compiled pattern was studied.
1743     In fixing this, I have also improved the studying algorithm for such
1744     classes (slightly).
1746     2. Three internal functions had redundant arguments passed to them. Removal
1747     might give a very teeny performance improvement.
1749     3. Documentation bug: the value of the capture_top field in a callout is *one
1750     more than* the number of the hightest numbered captured substring.
1752     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1753     in incorrectly linking with a previously installed version. They now link
1754     explicitly with libpcre.la.
1756     5. configure.in no longer needs to recognize Cygwin specially.
1758     6. A problem in pcre.in for Windows platforms is fixed.
1760     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1761     pcretest, it used to include the size of the study block as part of its
1762     output. Unfortunately, the structure contains a field that has a different
1763     size on different hardware architectures. This meant that the tests that
1764     showed this size failed. As the block is currently always of a fixed size,
1765     this information isn't actually particularly useful in pcretest output, so
1766     I have just removed it.
1768     8. Three pre-processor statements accidentally did not start in column 1.
1769     Sadly, there are *still* compilers around that complain, even though
1770     standard C has not required this for well over a decade. Sigh.
1772     9. In pcretest, the code for checking callouts passed small integers in the
1773     callout_data field, which is a void * field. However, some picky compilers
1774     complained about the casts involved for this on 64-bit systems. Now
1775     pcretest passes the address of the small integer instead, which should get
1776     rid of the warnings.
1778     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1779     both compile and run time, and gives an error if an invalid UTF-8 sequence
1780     is found. There is a option for disabling this check in cases where the
1781     string is known to be correct and/or the maximum performance is wanted.
1783     11. In response to a bug report, I changed one line in Makefile.in from
1785     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1786     to
1787     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1789     to look similar to other lines, but I have no way of telling whether this
1790     is the right thing to do, as I do not use Windows. No doubt I'll get told
1791     if it's wrong...
1794 nigel 69 Version 4.3 21-May-03
1795     ---------------------
1797     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1798     Makefile.
1800     2. Some refactoring to improve the quality of the code:
1802     (i) The utf8_table... variables are now declared "const".
1804     (ii) The code for \cx, which used the "case flipping" table to upper case
1805     lower case letters, now just substracts 32. This is ASCII-specific,
1806     but the whole concept of \cx is ASCII-specific, so it seems
1807     reasonable.
1809     (iii) PCRE was using its character types table to recognize decimal and
1810     hexadecimal digits in the pattern. This is silly, because it handles
1811     only 0-9, a-f, and A-F, but the character types table is locale-
1812     specific, which means strange things might happen. A private
1813     table is now used for this - though it costs 256 bytes, a table is
1814     much faster than multiple explicit tests. Of course, the standard
1815     character types table is still used for matching digits in subject
1816     strings against \d.
1818     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1819     ending in _t are). So I've renamed it as ESC_tee.
1821     3. The first argument for regexec() in the POSIX wrapper should have been
1822     defined as "const".
1824     4. Changed pcretest to use malloc() for its buffers so that they can be
1825     Electric Fenced for debugging.
1827     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1828     to read one or more bytes before the start of the subject string. Often this
1829     had no effect on PCRE's behaviour, but in some circumstances it could
1830     provoke a segmentation fault.
1832     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1833     to try to read one or more bytes before the start of the subject string.
1835     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1836     UTF-8 support could misbehave in various ways if the subject string
1837     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1838     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1839     back over UTF-8 characters.)
1842 nigel 67 Version 4.2 14-Apr-03
1843     ---------------------
1845     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1847     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1848     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1849     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1850     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1851     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1852     and BUILD_EXEEXT
1853     Note: automatic setting of the BUILD variables is not yet working
1854     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1855     compile-time but not at link-time
1856     [LINK]: use for linking executables only
1857     make different versions for Windows and non-Windows
1858     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1859     libraries
1860     [LINK_FOR_BUILD]: new variable
1861     [OBJEXT]: use throughout
1862     [EXEEXT]: use throughout
1863     <winshared>: new target
1864     <wininstall>: new target
1865     <dftables.o>: use native compiler
1866     <dftables>: use native linker
1867     <install>: handle Windows platform correctly
1868     <clean>: ditto
1869     <check>: ditto
1870     copy DLL to top builddir before testing
1872     As part of these changes, -no-undefined was removed again. This was reported
1873     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1874     in any case.
1876     3. Some tidies to get rid of compiler warnings:
1878     . In the match_data structure, match_limit was an unsigned long int, whereas
1879     match_call_count was an int. I've made them both unsigned long ints.
1881     . In pcretest the fact that a const uschar * doesn't automatically cast to
1882     a void * provoked a warning.
1884     . Turning on some more compiler warnings threw up some "shadow" variables
1885     and a few more missing casts.
1887     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1888     option, a class that contained a single character with a value between 128
1889     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1891     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1892     option, a class that contained several characters, but with at least one
1893     whose value was between 128 and 255 caused PCRE to crash.
1896 nigel 65 Version 4.1 12-Mar-03
1897     ---------------------
1898 nigel 63
1899 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
1900     needed, and a string in dftables.c that was longer than standard compilers are
1901     required to support.
1903     2. Compiling with Sun's compiler found a few more places where the code could
1904     be tidied up in order to avoid warnings.
1906     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1907     first of these names is deprecated in the latest Autoconf in favour of the name
1908     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1909     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1910     analogy I have changed it to CFLAGS_FOR_BUILD.
1912     4. Added -no-undefined to the linking command in the Makefile, because this is
1913     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1914     linking step for the pcreposix library.
1916     5. PCRE was failing to diagnose the case of two named groups with the same
1917     name.
1919     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1920     literal character that is needed in the subject for a match, and scans along to
1921     ensure that it is present before embarking on the full matching process. This
1922     saves time in cases of nested unlimited repeats that are never going to match.
1923     Problem: the scan can take a lot of time if the subject is very long (e.g.
1924     megabytes), thus penalizing straightforward matches. It is now done only if the
1925     amount of subject to be scanned is less than 1000 bytes.
1927     7. A lesser problem with the same optimization is that it was recording the
1928     first character of an anchored pattern as "needed", thus provoking a search
1929     right along the subject, even when the first match of the pattern was going to
1930     fail. The "needed" character is now not set for anchored patterns, unless it
1931     follows something in the pattern that is of non-fixed length. Thus, it still
1932     fulfils its original purpose of finding quick non-matches in cases of nested
1933     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1936     Version 4.0 17-Feb-03
1937     ---------------------
1939 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
1940     extended to the end of string, PCRE compiled incorrect data. This could lead to
1941     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1943     2. Moved to autoconf 2.53 and libtool 1.4.2.
1945     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1946     the special perltest8 script is no longer needed - all the tests can be run
1947     from a single perltest script.
1949     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1950     by \s. It has now been removed in PCRE. This means it isn't recognized as
1951     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1952     class [:space:] *does* include VT, thereby creating a mess.
1954     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1955     space and tab.
1957     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1958     its new features into the main test script, reducing the number of scripts.
1960     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1961     were backward compatible, and made the (?i) apply to the whole pattern, as if
1962     /i were given. Now it behaves more logically, and applies the option setting
1963     only to what follows. PCRE has been changed to follow suit. However, if it
1964     finds options settings right at the start of the pattern, it extracts them into
1965     the global options, as before. Thus, they show up in the info data.
1967     8. Added support for the \Q...\E escape sequence. Characters in between are
1968     treated as literals. This is slightly different from Perl in that $ and @ are
1969     also handled as literals inside the quotes. In Perl, they will cause variable
1970     interpolation. Note the following examples:
1972     Pattern PCRE matches Perl matches
1974     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1975     \Qabc\$xyz\E abc\$xyz abc\$xyz
1976     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1978     For compatibility with Perl, \Q...\E sequences are recognized inside character
1979     classes as well as outside them.
1981     9. Re-organized 3 code statements in pcretest to avoid "overflow in
1982     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1983     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1984     signed/unsigned warnings.
1986     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1987     option for pcretest, so I've replaced it by a simple function that does just
1988     that job.
1990     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1991     "pcregrep -".
1993     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1994     Java package. This provides some syntactic sugar for simple cases of what my
1995     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1996     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1997     item, you can use this simplified notation. Note that only makes sense with
1998     greedy quantifiers. Consequently, the use of the possessive quantifier forces
1999     greediness, whatever the setting of the PCRE_UNGREEDY option.
2001     13. A change of greediness default within a pattern was not taking effect at
2002     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2003     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2004     was abstracted outside.
2006     14. PCRE now supports the \G assertion. It is true when the current matching
2007     position is at the start point of the match. This differs from \A when the
2008     starting offset is non-zero. Used with the /g option of pcretest (or similar
2009     code), it works in the same way as it does for Perl's /g option. If all
2010     alternatives of a regex begin with \G, the expression is anchored to the start
2011     match position, and the "anchored" flag is set in the compiled expression.
2013     15. Some bugs concerning the handling of certain option changes within patterns
2014     have been fixed. These applied to options other than (?ims). For example,
2015     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2016     been the other way round. Some of this was related to change 7 above.
2018     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2019     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2020     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2021     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2023     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2024     mode. Unlike ".", it always matches newline, whatever the setting of
2025     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2026     assertions. Perl allows it, but it doesn't (in general) work because it can't
2027     calculate the length of the lookbehind. At least, that's the case for Perl
2028     5.8.0 - I've been told they are going to document that it doesn't work in
2029     future.
2031     18. Added an error diagnosis for escapes that PCRE does not support: these are
2032     \L, \l, \N, \P, \p, \U, \u, and \X.
2034     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2035     reading past the end of the pattern in cases such as /[abcd/.
2037     20. PCRE was getting more memory than necessary for patterns with classes that
2038     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2040     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2041     compiling PCRE for use with Virtual Pascal.
2043     22. Small fix to the Makefile to make it work properly if the build is done
2044     outside the source tree.
2046     23. Added a new extension: a condition to go with recursion. If a conditional
2047     subpattern starts with (?(R) the "true" branch is used if recursion has
2048     happened, whereas the "false" branch is used only at the top level.
2050     24. When there was a very long string of literal characters (over 255 bytes
2051     without UTF support, over 250 bytes with UTF support), the computation of how
2052     much memory was required could be incorrect, leading to segfaults or other
2053     strange effects.
2055     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2056     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2057     there was a subsequent back reference to those brackets. This meant that, for
2058     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2059     possible to check for precisely this case. All we can do is abandon the
2060     optimization if .* occurs inside capturing brackets when there are any back
2061     references whatsoever. (See below for a better fix that came later.)
2063     26. The handling of the optimization for finding the first character of a
2064     non-anchored pattern, and for finding a character that is required later in the
2065     match were failing in some cases. This didn't break the matching; it just
2066     failed to optimize when it could. The way this is done has been re-implemented.
2068     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2070     28. Added a new feature that provides some of the functionality that Perl
2071     provides with (?{...}). The facility is termed a "callout". The way it is done
2072     in PCRE is for the caller to provide an optional function, by setting
2073     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2074     global variable. By default it is unset, which disables all calling out. To get
2075     the function called, the regex must include (?C) at appropriate points. This
2076     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2077     This provides a means of identifying different callout points. When PCRE
2078     reaches such a point in the regex, if pcre_callout has been set, the external
2079     function is called. It is provided with data in a structure called
2080     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2081     matching continues; if it returns a non-zero value, the match at the current
2082     point fails. However, backtracking will occur if possible. [This was changed
2083     later and other features added - see item 49 below.]
2085     29. pcretest is upgraded to test the callout functionality. It provides a
2086     callout function that displays information. By default, it shows the start of
2087     the match and the current position in the text. There are some new data escapes
2088     to vary what happens:
2090     \C+ in addition, show current contents of captured substrings
2091     \C- do not supply a callout function
2092     \C!n return 1 when callout number n is reached
2093     \C!n!m return 1 when callout number n is reached for the mth time
2095     30. If pcregrep was called with the -l option and just a single file name, it
2096     output "<stdin>" if a match was found, instead of the file name.
2098     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2099     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2100     pcre_exec(). This saves a malloc/free per call. The default value of
2101     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2102     when configuring.
2104     32. The default maximum size of a compiled pattern is 64K. There have been a
2105     few cases of people hitting this limit. The code now uses macros to handle the
2106     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2107     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2108     configuring. Tests 2 and 5 work only with 2-byte links because they output
2109     debugging information about compiled patterns.
2111     33. Internal code re-arrangements:
2113     (a) Moved the debugging function for printing out a compiled regex into
2114     its own source file (printint.c) and used #include to pull it into
2115     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2116     separate copies.
2118     (b) Defined the list of op-code names for debugging as a macro in
2119     internal.h so that it is next to the definition of the opcodes.
2121     (c) Defined a table of op-code lengths for simpler skipping along compiled
2122     code. This is again a macro in internal.h so that it is next to the
2123     definition of the opcodes.
2125     34. Added support for recursive calls to individual subpatterns, along the
2126     lines of Robin Houston's patch (but implemented somewhat differently).
2128     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2129     allow it to read and process whole directories in Win32. This code was
2130     contributed by Lionel Fourquaux; it has not been tested by me.
2132     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2133     used to name a group. Names consist of alphanumerics and underscores, and must
2134     be unique. Back references use the syntax (?P=name) and recursive calls use
2135     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2136     numbers. The function pcre_fullinfo() can be used after compilation to extract
2137     a name/number map. There are three relevant calls:
2139     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2140     PCRE_INFO_NAMECOUNT yields the number of entries
2141     PCRE_INFO_NAMETABLE yields a pointer to the map.
2143     The map is a vector of fixed-size entries. The size of each entry depends on
2144     the length of the longest name used. The first two bytes of each entry are the
2145     group number, most significant byte first. There follows the corresponding
2146     name, zero terminated. The names are in alphabetical order.
2148     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2149     case instead of 255. Making it the same both with and without UTF-8 support
2150     means that the same test output works with both.
2152     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2153     calling malloc() with a zero argument.
2155     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2156     optimization. I've improved things by keeping a bitmap of backreferences with
2157     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2158     fact referenced, the optimization can be applied. It is unlikely that a
2159     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2160     the match to follow \n) will appear inside brackets with a number greater than
2161     31, but if it does, any back reference > 31 suppresses the optimization.
2163     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2164     of disabling numbered capturing parentheses. Any opening parenthesis that is
2165     not followed by ? behaves as if it were followed by ?: but named parentheses
2166     can still be used for capturing (and they will acquire numbers in the usual
2167     way).
2169     41. Redesigned the return codes from the match() function into yes/no/error so
2170     that errors can be passed back from deep inside the nested calls. A malloc
2171     failure while inside a recursive subpattern call now causes the
2172     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2174     42. It is now possible to set a limit on the number of times the match()
2175     function is called in a call to pcre_exec(). This facility makes it possible to
2176     limit the amount of recursion and backtracking, though not in a directly
2177     obvious way, because the match() function is used in a number of different
2178     circumstances. The count starts from zero for each position in the subject
2179     string (for non-anchored patterns). The default limit is, for compatibility, a
2180     large number, namely 10 000 000. You can change this in two ways:
2182     (a) When configuring PCRE before making, you can use --with-match-limit=n
2183     to set a default value for the compiled library.
2185     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2186     a different value is set. See 45 below.
2188     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2190     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2191     of things that can be changed at compile time. The first argument specifies
2192     what is wanted and the second points to where the information is to be placed.
2193     The current list of available information is:
2197     The output is an integer that is set to one if UTF-8 support is available;
2198     otherwise it is set to zero.
2202     The output is an integer that it set to the value of the code that is used for
2203     newline. It is either LF (10) or CR (13).
2207     The output is an integer that contains the number of bytes used for internal
2208     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2212     The output is an integer that contains the threshold above which the POSIX
2213     interface uses malloc() for output vectors. See item 31 above.
2217     The output is an unsigned integer that contains the default limit of the number
2218     of match() calls in a pcre_exec() execution. See 42 above.
2220     44. pcretest has been upgraded by the addition of the -C option. This causes it
2221     to extract all the available output from the new pcre_config() function, and to
2222     output it. The program then exits immediately.
2224     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2225     order to support additional features. One way would have been to define
2226     pcre_exec2() (for example) with extra arguments, but this would not have been
2227     extensible, and would also have required all calls to the original function to
2228     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2229     is used for passing in "extra" data from pcre_study().
2231     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2232     contains the following fields:
2234     flags a bitmap indicating which of the following fields are set
2235     study_data opaque data from pcre_study()
2236     match_limit a way of specifying a limit on match() calls for a specific
2237     call to pcre_exec()
2238     callout_data data for callouts (see 49 below)
2240     The flag bits are also defined in pcre.h, and are
2246     The pcre_study() function now returns one of these new pcre_extra blocks, with
2247     the actual study data pointed to by the study_data field, and the
2248     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2249     before. That is, this change is entirely upwards-compatible and requires no
2250     change to existing code.
2252     If you want to pass in additional data to pcre_exec(), you can either place it
2253     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2254     block.
2256     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2257     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2258     times with different match limits, until it finds the minimum value needed for
2259     pcre_exec() to complete. The value is then output. This can be instructive; for
2260     most simple matches the number is quite small, but for pathological cases it
2261     gets very large very quickly.
2263     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2264     returns the size of the data block pointed to by the study_data field in a
2265     pcre_extra block, that is, the value that was passed as the argument to
2266     pcre_malloc() when PCRE was getting memory in which to place the information
2267     created by pcre_study(). The fourth argument should point to a size_t variable.
2268     pcretest has been extended so that this information is shown after a successful
2269     pcre_study() call when information about the compiled regex is being displayed.
2271     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2272     because what follows is always an absolute path. (Later: it turns out that this
2273     is more than cosmetic for MinGW, because it doesn't like empty path
2274     components.)
2276     49. Some changes have been made to the callout feature (see 28 above):
2278     (i) A callout function now has three choices for what it returns:
2280     0 => success, carry on matching
2281     > 0 => failure at this point, but backtrack if possible
2282     < 0 => serious error, return this value from pcre_exec()
2284     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2285     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2286     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2287     use by callout functions. It will never be used by PCRE itself.
2289     (ii) The pcre_extra structure (see 45 above) has a void * field called
2290     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2291     pcre_callout_block structure has a field of the same name. The contents of
2292     the field passed in the pcre_extra structure are passed to the callout
2293     function in the corresponding field in the callout block. This makes it
2294     easier to use the same callout-containing regex from multiple threads. For
2295     testing, the pcretest program has a new data escape
2297     \C*n pass the number n (may be negative) as callout_data
2299     If the callout function in pcretest receives a non-zero value as
2300     callout_data, it returns that value.
2302     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2303     there were some redundant $(CFLAGS) in commands that are now specified as
2304     $(LINK), which already includes $(CFLAGS).
2306     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2307     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2308     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2309     one-byte characters throughout. Note that case-insensitive matching applies
2310     only to characters whose values are less than 256. PCRE doesn't support the
2311     notion of cases for higher-valued characters.
2313     (i) A character class whose characters are all within 0-255 is handled as
2314     a bit map, and the map is inverted for negative classes. Previously, a
2315     character > 255 always failed to match such a class; however it should
2316     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2318     (ii) A negated character class with a single character < 255 is coded as
2319     "not this character" (OP_NOT). This wasn't working properly when the test
2320     character was multibyte, either singly or repeated.
2322     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2323     mode, for example: \x{100}{2,3}.
2325     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2326     singly or repeated) now correctly test multibyte characters. However,
2327     PCRE doesn't recognize any characters with values greater than 255 as
2328     digits, spaces, or word characters. Such characters always match \D, \S,
2329     and \W, and never match \d, \s, or \w.
2331     (v) Classes may now contain characters and character ranges with values
2332     greater than 255. For example: [ab\x{100}-\x{400}].
2334     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2335     PCRE in UTF-8 mode.
2337     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2338     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2339     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2340     value.)
2342     53. The single man page has become too large. I have therefore split it up into
2343     a number of separate man pages. These also give rise to individual HTML pages;
2344     these are now put in a separate directory, and there is an index.html page that
2345     lists them all. Some hyperlinking between the pages has been installed.
2347     54. Added convenience functions for handling named capturing parentheses.
2349     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2350     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2351     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2352     are faulted.
2354     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2355     calling configure. These values are used when compiling the dftables.c program
2356     which is run to generate the source of the default character tables. They
2357     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2358     you will need to set these values.
2360     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2363     Version 3.9 02-Jan-02
2364 nigel 61 ---------------------
2366     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2368     2. If --disable-static was given, the building process failed when trying to
2369     build pcretest and pcregrep. (For some reason it was using libtool to compile
2370     them, which is not right, as they aren't part of the library.)
2373 nigel 59 Version 3.8 18-Dec-01
2374     ---------------------
2376     1. The experimental UTF-8 code was completely screwed up. It was packing the
2377     bytes in the wrong order. How dumb can you get?
2380 nigel 57 Version 3.7 29-Oct-01
2381     ---------------------
2383     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2384     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2385     this didn't happen under Solaris 8, where I normally test things.
2387 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2388     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2389     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2390     this fix an hour or so after the initial 3.7 release.)
2391 nigel 57
2392 nigel 59
2393 nigel 55 Version 3.6 23-Oct-01
2394     ---------------------
2396     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2397     offsets passed as NULL with zero offset count.
2399     2. The config.guess and config.sub files had not been updated when I moved to
2400     the latest autoconf.
2403 nigel 53 Version 3.5 15-Aug-01
2404     ---------------------
2405 nigel 5
2406 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2407     had been forgotten.
2409     2. By using declared but undefined structures, we can avoid using "void"
2410     definitions in pcre.h while keeping the internal definitions of the structures
2411     private.
2413     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2414     user point of view, this means that both static and shared libraries are built
2415     by default, but this can be individually controlled. More of the work of
2416     handling this static/shared cases is now inside libtool instead of PCRE's make
2417     file.
2419     4. The pcretest utility is now installed along with pcregrep because it is
2420     useful for users (to test regexs) and by doing this, it automatically gets
2421     relinked by libtool. The documentation has been turned into a man page, so
2422     there are now .1, .txt, and .html versions in /doc.
2424     5. Upgrades to pcregrep:
2425     (i) Added long-form option names like gnu grep.
2426     (ii) Added --help to list all options with an explanatory phrase.
2427     (iii) Added -r, --recursive to recurse into sub-directories.
2428     (iv) Added -f, --file to read patterns from a file.
2430     6. pcre_exec() was referring to its "code" argument before testing that
2431     argument for NULL (and giving an error if it was NULL).
2433     7. Upgraded Makefile.in to allow for compiling in a different directory from
2434     the source directory.
2436     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2437     options bits, the pointer it was passed was to an int instead of to an unsigned
2438     long int. This mattered only on 64-bit systems.
2440     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2441     generated) instead of pcre.in, which it its source. Also made the same change
2442     in several of the .c files.
2444     10. A new release of gcc defines printf() as a macro, which broke pcretest
2445     because it had an ifdef in the middle of a string argument for printf(). Fixed
2446     by using separate calls to printf().
2448     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2449     script, to force use of CR or LF instead of \n in the source. On non-Unix
2450     systems, the value can be set in config.h.
2452     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2453     absolute limit. Changed the text of the error message to make this clear, and
2454     likewise updated the man page.
2456     13. The limit of 99 on the number of capturing subpatterns has been removed.
2457     The new limit is 65535, which I hope will not be a "real" limit.
2460 nigel 51 Version 3.4 22-Aug-00
2461     ---------------------
2463     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2465     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2468 nigel 49 Version 3.3 01-Aug-00
2469     ---------------------
2471     1. If an octal character was given, but the value was greater than \377, it
2472     was not getting masked to the least significant bits, as documented. This could
2473     lead to crashes in some systems.
2475     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2476     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2478     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2479     These just pass their arguments on to (pcre_free)(), but they are provided
2480     because some uses of PCRE bind it to non-C systems that can call its functions,
2481     but cannot call free() or pcre_free() directly.
2483     4. Add "make test" as a synonym for "make check". Corrected some comments in
2484     the Makefile.
2486     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2487     Makefile.
2489     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2490     command called pgrep for grepping around the active processes.
2492     7. Added the beginnings of support for UTF-8 character strings.
2494     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2495     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2496     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2497     out for the ar command.)
2500 nigel 47 Version 3.2 12-May-00
2501     ---------------------
2503     This is purely a bug fixing release.
2505     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2506     of ZA. This was just one example of several cases that could provoke this bug,
2507     which was introduced by change 9 of version 2.00. The code for breaking
2508     infinite loops after an iteration that matches an empty string was't working
2509     correctly.
2511     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2512     when matched against abbab (for example). After matching an empty string, it
2513     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2514     caused it to match further down the string than it should.
2516     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2517     was there because it doesn't seem to be needed, and it causes trouble on some
2518     systems, as it is not a Standard C header. It has been removed.
2520     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2521     were reported on the Macintosh. The changes were from
2523     while ((c = *(++ptr)) != 0 && c != '\n');
2524     to
2525     while ((c = *(++ptr)) != 0 && c != '\n') ;
2527     Totally extraordinary, but if that's what it takes...
2529     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2530     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2531     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2532     assumes the way PCRE uses memmove() (always moving upwards).
2534     6. PCRE is being used in one environment where strchr() is not available. There
2535     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2536     faster code anyway.
2539 nigel 45 Version 3.1 09-Feb-00
2540     ---------------------
2542     The only change in this release is the fixing of some bugs in Makefile.in for
2543     the "install" target:
2545     (1) It was failing to install pcreposix.h.
2547     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2550 nigel 43 Version 3.0 01-Feb-00
2551     ---------------------
2552 nigel 41
2553     1. Add support for the /+ modifier to perltest (to output $` like it does in
2554     pcretest).
2556     2. Add support for the /g modifier to perltest.
2558     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2559     matches null strings.
2561     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2562     pattern. Perl treats empty patterns specially - it reuses the most recent
2563     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2564     effect.
2566     5. The POSIX interface was broken in that it was just handing over the POSIX
2567     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2568     required a bigger vector, with some working space on the end. This means that
2569     the POSIX wrapper now has to get and free some memory, and copy the results.
2571 nigel 43 6. Added some simple autoconf support, placing the test data and the
2572     documentation in separate directories, re-organizing some of the
2573     information files, and making it build pcre-config (a GNU standard). Also added
2574     libtool support for building PCRE as a shared library, which is now the
2575     default.
2576 nigel 41
2577 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2578     09 are not valid octal constants. Single digits will be used for minor values
2579     less than 10.
2581     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2582     existing programs that set these in the POSIX interface can use PCRE without
2583     modification.
2585     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2586     return all that pcre_info() returns, plus additional data. The pcre_info()
2587     function is retained for compatibility, but is considered to be obsolete.
2589     10. Added experimental recursion feature (?R) to handle one common case that
2590     Perl 5.6 will be able to do with (?p{...}).
2592     11. Added support for POSIX character classes like [:alpha:], which Perl is
2593     adopting.
2596 nigel 39 Version 2.08 31-Aug-99
2597     ----------------------
2599     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2600     trying to match at the startoffset position, but instead was moving forward to
2601     the next newline as if a previous match had failed.
2603     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2604     and could get into a loop if a null string was matched other than at the start
2605     of the subject.
2607     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2608     be distinguished at compile time, and for completeness also added PCRE_DATE.
2610     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2611     in GnuWin32 environments.
2614 nigel 37 Version 2.07 29-Jul-99
2615     ----------------------
2617     1. The documentation is now supplied in plain text form and HTML as well as in
2618     the form of man page sources.
2620     2. C++ compilers don't like assigning (void *) values to other pointer types.
2621     In particular this affects malloc(). Although there is no problem in Standard
2622     C, I've put in casts to keep C++ compilers happy.
2624     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2625     should be (const char *).
2627     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2628     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2629     However, I haven't made this a standard facility. The documentation doesn't
2630     mention it, and the Makefile doesn't support it.
2632     5. The Makefile now contains an "install" target, with editable destinations at
2633     the top of the file. The pcretest program is not installed.
2635     6. pgrep -V now gives the PCRE version number and date.
2637     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2638     causing the entire string to be ignored, instead of just the last character.
2640     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2641     non-matching string, it can take a very, very long time, even for strings of
2642     quite modest length, because of the nested recursion. PCRE now does better in
2643     some of these cases. It does this by remembering the last required literal
2644     character in the pattern, and pre-searching the subject to ensure it is present
2645     before running the real match. In other words, it applies a heuristic to detect
2646     some types of certain failure quickly, and in the above example, if presented
2647     with a string that has no trailing " it gives "no match" very quickly.
2649     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2650     other alternatives are tried instead.
2653 nigel 35 Version 2.06 09-Jun-99
2654     ----------------------
2656     1. Change pcretest's output for amount of store used to show just the code
2657     space, because the remainder (the data block) varies in size between 32-bit and
2658     64-bit systems.
2660     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2661     start matching at. This allows lookbehinds to work when searching for multiple
2662     occurrences in a string.
2664     3. Added additional options to pcretest for testing multiple occurrences:
2666     /+ outputs the rest of the string that follows a match
2667     /g loops for multiple occurrences, using the new startoffset argument
2668     /G loops for multiple occurrences by passing an incremented pointer
2670     4. PCRE wasn't doing the "first character" optimization for patterns starting
2671     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2672     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2673     the letter 'x'. On long subject strings, this gives a significant speed-up.
2676 nigel 33 Version 2.05 21-Apr-99
2677     ----------------------
2679     1. Changed the type of magic_number from int to long int so that it works
2680     properly on 16-bit systems.
2682     2. Fixed a bug which caused patterns starting with .* not to work correctly
2683     when the subject string contained newline characters. PCRE was assuming
2684     anchoring for such patterns in all cases, which is not correct because .* will
2685     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2686     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2687     must be retried after every newline in the subject.
2690 nigel 31 Version 2.04 18-Feb-99
2691     ----------------------
2693     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2694     computation of the store needed to hold the pattern was incorrect (too large).
2695     If such patterns were nested a few deep, this could multiply and become a real
2696     problem.
2698     2. Added /M option to pcretest to show the memory requirement of a specific
2699     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2701     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2702     compiled in such a way that the backtracking after subsequent failure was
2703     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2704     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2707 nigel 29 Version 2.03 02-Feb-99
2708     ----------------------
2710     1. Fixed typo and small mistake in man page.
2712 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2713     LICENCE file containing the conditions.
2714 nigel 29
2715     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2716     Perl, that is the internal \ allows the delimiter to be included in the
2717     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2718     the final delimiter, add \ to the end of the pattern (to test the error).
2720     4. Added the convenience functions for extracting substrings after a successful
2721     match. Updated pcretest to make it able to test these functions.
2724 nigel 27 Version 2.02 14-Jan-99
2725     ----------------------
2727     1. Initialized the working variables associated with each extraction so that
2728     their saving and restoring doesn't refer to uninitialized store.
2730     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2731     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2732     fix the problem.
2734     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2735     calls, and wasn't printing the correct value for compiling calls. Increased the
2736     default value of LOOPREPEAT, and the number of significant figures in the
2737     times.
2739     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2741     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2742     a building problem on Windows NT with a FAT file system.
2745 nigel 25 Version 2.01 21-Oct-98
2746     ----------------------
2748     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2749     to character tables built by pcre_maketables() in the current locale. If NULL
2750     is passed, the default tables are used.
2753 nigel 23 Version 2.00 24-Sep-98
2754 nigel 21 ----------------------
2756 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2757     it any more.
2759     2. Allow quantification of (?>) groups, and make it work correctly.
2761     3. The first character computation wasn't working for (?>) groups.
2763     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2764     end of the subject) and add 5.005's \z, which really does match only at the
2765     very end of the subject.
2767     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2769     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2770     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2771     localized options. All options to pcre_study() were also removed.
2773     7. Add other new features from 5.005:
2775     $(?<= positive lookbehind
2776     $(?<! negative lookbehind
2777     (?imsx-imsx) added the unsetting capability
2778     such a setting is global if at outer level; local otherwise
2779     (?imsx-imsx:) non-capturing groups with option setting
2780     (?(cond)re|re) conditional pattern matching
2782     A backreference to itself in a repeated group matches the previous
2783     captured string.
2785     8. General tidying up of studying (both automatic and via "study")
2786     consequential on the addition of new assertions.
2788     9. As in 5.005, unlimited repeated groups that could match an empty substring
2789     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2790     runtime if any iteration does actually match an empty substring.
2792     10. Include the RunTest script in the distribution.
2794     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2795     discrepancies, some of which were old and were also with respect to 5.004. They
2796     have now been fixed.
2799     Version 1.09 28-Apr-98
2800     ----------------------
2802 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2803     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2804     program crashes, or just wrong answers. This did not apply to negated classes
2805     containing more than one character, or to minima other than one.
2808 nigel 19 Version 1.08 27-Mar-98
2809     ----------------------
2811     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2813     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2814     latter must appear before anything that relies on it in the pattern.
2817 nigel 17 Version 1.07 16-Feb-98
2818     ----------------------
2820     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2821     repeat of a potentially empty string).
2824 nigel 15 Version 1.06 23-Jan-98
2825     ----------------------
2827     1. Added Markus Oberhumer's little patches for C++.
2829     2. Literal strings longer than 255 characters were broken.
2832 nigel 13 Version 1.05 23-Dec-97
2833     ----------------------
2835     1. Negated character classes containing more than one character were failing if
2836     PCRE_CASELESS was set at run time.
2839 nigel 11 Version 1.04 19-Dec-97
2840     ----------------------
2842     1. Corrected the man page, where some "const" qualifiers had been omitted.
2844     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2845     input syntax.
2847     3. Fixed memory leak which occurred when a regex with back references was
2848     matched with an offsets vector that wasn't big enough. The temporary memory
2849     that is used in this case wasn't being freed if the match failed.
2851     4. Tidied pcretest to ensure it frees memory that it gets.
2853     5. Temporary memory was being obtained in the case where the passed offsets
2854     vector was exactly big enough.
2856     6. Corrected definition of offsetof() from change 5 below.
2858     7. I had screwed up change 6 below and broken the rules for the use of
2859     setjmp(). Now fixed.
2862 nigel 9 Version 1.03 18-Dec-97
2863     ----------------------
2865     1. A erroneous regex with a missing opening parenthesis was correctly
2866     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2867     on some systems.
2869     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2870     it was reported that one broken compiler failed on the former because "code" is
2871     also an independent variable.
2873     3. The erroneous regex a[]b caused an array overrun reference.
2875     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2876     fail on data ending with that character. (It was going on too far, and checking
2877     the next character, typically a binary zero.) This was specific to the
2878     optimized code for single-character negative classes.
2880     5. Added a contributed patch from the TIN world which does the following:
2882     + Add an undef for memmove, in case the the system defines a macro for it.
2884     + Add a definition of offsetof(), in case there isn't one. (I don't know
2885     the reason behind this - offsetof() is part of the ANSI standard - but
2886     it does no harm).
2888     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2889     most of the places where whitespace preceded '#'. I have given up and
2890     allowed the remaining 2 cases to be at the margin.
2892     + Rename some variables in pcre to eliminate shadowing. This seems very
2893     pedantic, but does no harm, of course.
2895     6. Moved the call to setjmp() into its own function, to get rid of warnings
2896     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2898     7. Constructs such as \d{8,} were compiling into the equivalent of
2899 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2900 nigel 9 outcome, but in this particular case used more store than had been allocated,
2901     which caused the bug to be discovered because it threw up an internal error.
2903     8. The debugging code in both pcre and pcretest for outputting the compiled
2904     form of a regex was going wrong in the case of back references followed by
2905     curly-bracketed repeats.
2908 nigel 7 Version 1.02 12-Dec-97
2909     ----------------------
2911     1. Typos in pcre.3 and comments in the source fixed.
2913     2. Applied a contributed patch to get rid of places where it used to remove
2914     'const' from variables, and fixed some signed/unsigned and uninitialized
2915     variable warnings.
2917     3. Added the "runtest" target to Makefile.
2919     4. Set default compiler flag to -O2 rather than just -O.
2922 nigel 5 Version 1.01 19-Nov-97
2923     ----------------------
2925     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2926     like /([ab]*)*/, that is, for classes with more than one character in them.
2928     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2929     as /((?>a*))*/ (a PCRE_EXTRA facility).
2932     Version 1.00 18-Nov-97
2933     ----------------------
2935     1. Added compile-time macros to support systems such as SunOS4 which don't have
2936     memmove() or strerror() but have other things that can be used instead.
2938     2. Arranged that "make clean" removes the executables.
2941 nigel 3 Version 0.99 27-Oct-97
2942     ----------------------
2944     1. Fixed bug in code for optimizing classes with only one character. It was
2945     initializing a 32-byte map regardless, which could cause it to run off the end
2946     of the memory it had got.
2948     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2951     Version 0.98 22-Oct-97
2952     ----------------------
2954     1. Fixed bug in code for handling temporary memory usage when there are more
2955     back references than supplied space in the ovector. This could cause segfaults.
2958     Version 0.97 21-Oct-97
2959     ----------------------
2961     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2963     2. Optimized negated single characters not to use a bit map.
2965     3. Brought error texts together as macro definitions; clarified some of them;
2966     fixed one that was wrong - it said "range out of order" when it meant "invalid
2967     escape sequence".
2969     4. Changed some char * arguments to const char *.
2971     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2973     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2974     pcretest.
2977     Version 0.96 16-Oct-97
2978     ----------------------
2980     1. Added a simple "pgrep" utility to the distribution.
2982     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2983     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2984     where "ddd" means "one or more decimal digits".
2986     3. Fixed serious bug. If a pattern had a back reference, but the call to
2987     pcre_exec() didn't supply a large enough ovector to record the related
2988     identifying subpattern, the match always failed. PCRE now remembers the number
2989     of the largest back reference, and gets some temporary memory in which to save
2990     the offsets during matching if necessary, in order to ensure that
2991     backreferences always work.
2993     4. Increased the compatibility with Perl in a number of ways:
2995     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2996     to request this handling. The option can be set at compile or exec time.
2998     (b) $ matches before a terminating newline by default; an option
2999     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3000     mode). The option can be set at compile or exec time.
3002     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3003     the same as Perl's. If the decimal number it represents is less than 10
3004     or there aren't that many previous left capturing parentheses, an octal
3005     escape is read. Inside a character class, it's always an octal escape,
3006     even if it is a single digit.
3008     (d) An escaped but undefined alphabetic character is taken as a literal,
3009     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3010     escapes.
3012     (e) {0} is now permitted. (The previous item is removed from the compiled
3013     pattern).
3015     5. Changed all the names of code files so that the basic parts are no longer
3016     than 10 characters, and abolished the teeny "globals.c" file.
3018     6. Changed the handling of character classes; they are now done with a 32-byte
3019     bit map always.
3021     7. Added the -d and /D options to pcretest to make it possible to look at the
3022     internals of compilation without having to recompile pcre.
3025     Version 0.95 23-Sep-97
3026     ----------------------
3028     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3029     \x20 at the start of a run of normal characters. These were being treated as
3030     real characters, instead of the source characters being re-checked.
3033     Version 0.94 18-Sep-97
3034     ----------------------
3036     1. The functions are now thread-safe, with the caveat that the global variables
3037     containing pointers to malloc() and free() or alternative functions are the
3038     same for all threads.
3040     2. Get pcre_study() to generate a bitmap of initial characters for non-
3041     anchored patterns when this is possible, and use it if passed to pcre_exec().
3044     Version 0.93 15-Sep-97
3045     ----------------------
3047     1. /(b)|(:+)/ was computing an incorrect first character.
3049     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3050     but not actually doing anything yet.
3052     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3053     as Perl does (e.g. [-az] or [az-]).
3055     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3056     all possible positions.
3058     5. Split up into different modules to avoid including unneeded functions in a
3059     compiled binary. However, compile and exec are still in one module. The "study"
3060     function is split off.
3062     6. The character tables are now in a separate module whose source is generated
3063     by an auxiliary program - but can then be edited by hand if required. There are
3064     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3065     toupper() in the code.
3067     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3068     make them global. Abolish the function for setting them, as the caller can now
3069     set them directly.
3072     Version 0.92 11-Sep-97
3073     ----------------------
3075     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3076     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3078     2. Caseless matching was not working in character classes if the characters in
3079     the pattern were in upper case.
3081     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3083     4. Make PCRE_ANCHORED public and accept as a compile option.
3085     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3086     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3087     pass them.
3089     6. Give an error if bad option bits passed at compile or run time.
3091     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3092     pcretest to cause it to pass that flag.
3094     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3095     options, and the first character, if set.
3097     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3100     Version 0.91 10-Sep-97
3101     ----------------------
3103     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3104     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3106     2. PCRE was looping on encountering an indefinitely repeated back reference to
3107     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3108     Perl does - treats the match as successful.
3110     ****


Name Value
svn:eol-style native
svn:keywords "Author Date Id Revision Url"

ViewVC Help
Powered by ViewVC 1.1.12