ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log

Revision 285 - (hide annotations) (download)
Wed Dec 12 17:03:50 2007 UTC (7 years, 4 months ago) by ph10
File size: 146155 byte(s)
Fix bad compiled code for things like /\pL{2}+/ in which a possessive 
quantifier with a fixed limit was applied to a character property.

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 264
10     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 265
14     3. The same bug as (2) above applied to negated POSIX classes such as
15     [:^space:].
16 ph10 267
17     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     I have changed it.
20 ph10 268
21     5. The construct (?&) was not diagnosed as a syntax error (it referenced the
22     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 269
29     6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
30     this is right because (?- can be followed by option settings as well as by
31     digits. I have, however, made the messages clearer.
32 ph10 270
33     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 274
39     8. Change "alphameric" to the more common word "alphanumeric" in comments
40 ph10 275 and messages.
42     9. Fix two occurrences of "backslash" in comments that should have been
43     "backspace".
44 ph10 276
45     10. Remove two redundant lines of code that can never be obeyed (their function
46     was moved elsewhere).
47 ph10 277
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     characters that have the same character type, but are in different scripts.
51     It amalgamated them into a single range, with the script of the first of
52     them. In other words, some characters were in the wrong script. There were
53     thirteen such cases, affecting characters in the following ranges:
55     U+002b0 - U+002c1
56     U+0060c - U+0060d
57     U+0061e - U+00612
58     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 279
69     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.
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.
78 ph10 282
79     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     being skipped when checking for a possible empty match (negative lookaheads
82     and both kinds of lookbehind were skipped).
83 ph10 284
84     15. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
85     inclusion of <windows.h> to before rather than after the definition of
86     INVALID_FILE_ATTRIBUTES (patch from David Byron).
87 ph10 285
88     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
95 ph10 260 Version 7.4 21-Sep-07
96 ph10 230 ---------------------
98     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
99 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
100     LF". That isn't really right - the whole point of the change was to try to
101     help when there was an actual mention of one of the two characters. So now
102     the change happens only if \r or \n (or a literal CR or LF) character is
103 ph10 230 encountered.
104 ph10 231
105     2. The 32-bit options word was also used for 6 internal flags, but the numbers
106     of both had grown to the point where there were only 3 bits left.
107     Fortunately, there was spare space in the data structure, and so I have
108     moved the internal flags into a new 16-bit field to free up more option
109 ph10 230 bits.
110 ph10 231
111     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
112     but did not set the internal JCHANGED flag - either of these is enough to
113     control the way the "get" function works - but the PCRE_INFO_JCHANGED
114     facility is supposed to tell if (?J) was ever used, so now (?J) at the
115 ph10 230 start sets both bits.
117 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
118     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
119 ph10 230
120 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
122     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
123 ph10 233 compatibility, even though it is no longer used.
124 ph10 243
125     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
126 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
127 ph10 259 windows.h file is present (where different names are used). [This was
128 ph10 257 reversed later after testing - see 16 below.]
129 ph10 243
130     8. Changed all #include <config.h> to #include "config.h". There were also
131 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
132 ph10 243
133 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
134 ph10 243 sequence off the lines that it output.
136     10. It was pointed out to me that arrays of string pointers cause lots of
137     relocations when a shared library is dynamically loaded. A technique of
138     using a single long string with a table of offsets can drastically reduce
139     these. I have refactored PCRE in four places to do this. The result is
140 ph10 240 dramatic:
141 ph10 243
142 ph10 240 Originally: 290
143     After changing UCP table: 187
144 ph10 243 After changing error message table: 43
145 ph10 240 After changing table of "verbs" 36
146     After changing table of Posix names 22
147 ph10 243
148 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
149 ph10 247
150 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
151 ph10 247 unicode-properties was also set.
153 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
154 ph10 231
155 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
156     checked only for CRLF.
157 ph10 233
158 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
160 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
161 ph10 253
162 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
163 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
164     entirely. This removes changes made in 7 above.
165 ph10 256
166 ph10 261 17. The CMake files have been updated, and there is now more information about
167     building with CMake in the NON-UNIX-USE document.
168 ph10 257
169 ph10 261
170 ph10 228 Version 7.3 28-Aug-07
171 ph10 157 ---------------------
173 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
174     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
175     brackets there is not right, since it causes compilers to look for an
176     installed pcre.h, not the version that is in the source that is being
177     compiled (which of course may be different). I have changed it back to:
178 ph10 197
179 ph10 189 #include "pcre.h"
180 ph10 197
181     I have a vague recollection that the change was concerned with compiling in
182     different directories, but in the new build system, that is taken care of
183     by the VPATH setting the Makefile.
185 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
186     when the subject happened to end in the byte 0x85 (e.g. if the last
187     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
188     characters but of course it shouldn't be taken as a newline when it is part
189     of another character. The bug was that, for an unlimited repeat of . in
190     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
191     characters when looking for a newline.
192 ph10 197
193     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
195     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
196     in debug output.
198 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
199     long printing in the pcrecpp unittest when running under MinGW.
200 ph10 189
201 ph10 197 6. ESC_K was left out of the EBCDIC table.
202 ph10 189
203 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
204     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
205     limit also applies to "virtual nesting" when a pattern is recursive, and in
206     this case 1000 isn't so big. I have been able to remove this limit at the
207     expense of backing off one optimization in certain circumstances. Normally,
208     when pcre_exec() would call its internal match() function recursively and
209     immediately return the result unconditionally, it uses a "tail recursion"
210     feature to save stack. However, when a subpattern that can match an empty
211     string has an unlimited repetition quantifier, it no longer makes this
212     optimization. That gives it a stack frame in which to save the data for
213     checking that an empty string has been matched. Previously this was taken
214     from the 1000-entry workspace that had been reserved. So now there is no
215     explicit limit, but more stack is used.
216 ph10 189
217 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
218     syntax that is required for Windows, and which was going wrong for the
219     pcreposix and pcrecpp parts of the library. These were overlooked when this
220     problem was solved for the main library.
221 ph10 197
222 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
223     the size of patterns that contain repeated groups with explicit upper
224     limits. As the maximum quantifier is 65535, the maximum group length was
225     set at 30,000 so that the product of these two numbers did not overflow a
226     32-bit integer. However, it turns out that people want to use groups that
227     are longer than 30,000 bytes (though not repeat them that many times).
228     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
229     made it possible to implement the integer overflow checks in a much more
230     dynamic way, which I have now done. The artificial limitation on group
231     length has been removed - we now have only the limit on the total length of
232     the compiled pattern, which depends on the LINK_SIZE setting.
233 ph10 208
234     10. Fixed a bug in the documentation for get/copy named substring when
235     duplicate names are permitted. If none of the named substrings are set, the
236     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
237     empty string.
239     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
240     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
241     because the ] is interpreted as the first data character and the
242     terminating ] is not found. PCRE has been made compatible with Perl in this
243     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
244     cause memory overwriting.
246 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
247     string has been matched (to stop an infinite loop). It was not recognizing
248 ph10 208 a conditional subpattern that could match an empty string if that
249 ph10 206 subpattern was within another subpattern. For example, it looped when
250 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
251 ph10 206 condition was not nested. This bug has been fixed.
252 ph10 208
253 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
254     past the start of the subject in the presence of bytes with the top bit
255     set, for example "\x8aBCD".
256 ph10 211
257 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
258     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
259 ph10 200
260 ph10 211 14. Optimized (?!) to (*FAIL).
261 ph10 202
262 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
263     This restricts code points to be within the range 0 to 0x10FFFF, excluding
264     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
265     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
266     does: it's just the validity check that is more restrictive.
267 ph10 220
268     16. Inserted checks for integer overflows during escape sequence (backslash)
269     processing, and also fixed erroneous offset values for syntax errors during
270     backslash processing.
272 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
273 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
275 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
276     caused an overrun.
277 ph10 220
278     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
279     something other than just ASCII characters) inside a group that had an
280     unlimited repeat caused a loop at compile time (while checking to see
281     whether the group could match an empty string).
283 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
284     [\P{Any}] did so. (Error in the code for printing property names.)
285 ph10 210
286 ph10 220 21. An orphan \E inside a character class could cause a crash.
288     22. A repeated capturing bracket such as (A)? could cause a wild memory
289 ph10 218 reference during compilation.
290 ph10 220
291     23. There are several functions in pcre_compile() that scan along a compiled
292     expression for various reasons (e.g. to see if it's fixed length for look
293 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
294 ph10 220 present in the pattern. These operators have additional parameters compared
295     with \d, etc, and these were not being taken into account when moving along
296 ph10 218 the compiled data. Specifically:
297 ph10 220
298     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
299     length.
301     (b) An item such as \pL+ within a repeated group could cause crashes or
302 ph10 218 loops.
303 ph10 220
304 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
305 ph10 220 "reference to non-existent subpattern" error.
307 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
309 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
310 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
311 ph10 211
312 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
313 ph10 218
314 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
315 ph10 223 character were causing crashes (broken optimization).
316 ph10 227
317 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
318 ph10 227 \p or \P) caused a compile-time loop.
320 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
321     break. For example, the unstudied pattern [\r\n]A does not match the string
322     "\r\nA" because change 7.0/46 below moves the current point on by two
323     characters after failing to match at the start. However, the pattern \nA
324 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
325     the same is true. There doesn't seem any very clean way out of this, but
326     what I have chosen to do makes the common cases work: PCRE now takes note
327     of whether there can be an explicit match for \r or \n anywhere in the
328     pattern, and if so, 7.0/46 no longer applies. As part of this change,
329     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
330     pattern has explicit CR or LF references.
331 ph10 222
332 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
333 ph10 223
334 ph10 227
335 ph10 189 Version 7.2 19-Jun-07
336     ---------------------
338 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
339     which is apparently normally available under Windows.
340 ph10 159
341     2. Re-jig the pcregrep tests with different newline settings in an attempt
342     to make them independent of the local environment's newline setting.
343 ph10 157
344 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
345 ph10 165
346 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
347     was not 2, because the output contained actual offsets. The recent new
348 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
349     usable with all link sizes.
351 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
352     stack recursion. This gives a massive performance boost under BSD, but just
353 ph10 165 a small improvement under Linux. However, it saves one field in the frame
354 ph10 164 in all cases.
355 ph10 172
356 ph10 166 6. Added more features from the forthcoming Perl 5.10:
357 ph10 172
358 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
359     recursion call. It refers to the nth most recently opened parentheses.
360 ph10 172
361 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
362 ph10 172 to be opened parentheses.
364     (c) Conditions that refer to capturing parentheses can be specified
365 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
366 ph10 172
367 ph10 168 (d) \K resets the start of the current match so that everything before
368 ph10 172 is not part of it.
370 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
371 ph10 172
372 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
373 ph10 172 reference syntax.
374 ph10 182
375 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
376 ph10 182 alternative starts with the same number.
377 ph10 172
378 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
380 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
383     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
384     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
385 ph10 170 for detecting groups that can match an empty string.
386 ph10 159
387 ph10 172 9. A pattern with a very large number of alternatives (more than several
388     hundred) was running out of internal workspace during the pre-compile
389     phase, where pcre_compile() figures out how much memory will be needed. A
390     bit of new cunning has reduced the workspace needed for groups with
391     alternatives. The 1000-alternative test pattern now uses 12 bytes of
392     workspace instead of running out of the 4096 that are available.
393 ph10 182
394 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
395 ph10 172
396 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
397     The report of the bug said:
398 ph10 182
399 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
400     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
401 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
402 ph10 185
403 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
404 ph10 185 it matched the wrong number of bytes.
405 ph10 172
406 ph10 179
407 ph10 155 Version 7.1 24-Apr-07
408 ph10 98 ---------------------
410 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
411 ph10 122 that is more "standard", making use of automake and other Autotools. There
412 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
413     on this.
414 ph10 111
415     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
416     for recursive directory scanning broke on some systems because the files
417     are not scanned in any specific order and on different systems the order
418     was different. A call to "sort" has been inserted into RunGrepTest for the
419     approprate test as a short-term fix. In the longer term there may be an
420 ph10 100 alternative.
421 ph10 111
422 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
423 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
424     people do their own conversions for various reasons). The problems
425     concerned the use of low-level troff macros .br and .in. I have therefore
426     removed all such uses from the man pages (some were redundant, some could
427 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
428     HTML has been updated to handle .nf/.fi and to complain if it encounters
429     .br or .in.
430 ph10 111
431 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
432 ph10 123 arranged for config.h to be included in the distribution, with the name
433 ph10 111 config.h.generic, for the benefit of those who have to compile without
434     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
436     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
437     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
438 ph10 127 makevp.bat for the current PCRE, using the additional files
439 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
440 ph10 111
441     6. A Windows user reported a minor discrepancy with test 2, which turned out
442     to be caused by a trailing space on an input line that had got lost in his
443 ph10 102 copy. The trailing space was an accident, so I've just removed it.
444 ph10 111
445 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
446 ph10 111 that is needed.
448 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
449     as "const" (a) because they are and (b) because it helps the PHP
450     maintainers who have recently made a script to detect big data structures
451 ph10 111 in the php code that should be moved to the .rodata section. I remembered
452     to update Builducptable as well, so it won't revert if ucptable.h is ever
453 ph10 105 re-created.
454 ph10 111
455     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
456 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
457 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
458     support is not required. This saves 1.5-2K of code, which is important in
459 ph10 107 some applications.
460 ph10 111
461 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
462 ph10 111 so as not to refer to the tables, even though these functions will never be
463     called when UTF-8 support is disabled. Otherwise there are problems with a
464     shared library.
466 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
468     (a) It was defining its arguments as char * instead of void *.
470 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
471     a long time ago when I wrote it, but is no longer the case.
473 ph10 118 The emulated memove() is provided for those environments that have neither
474 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
475 ph10 118 is clearly not the case, as these two bugs were recently reported.
476 ph10 123
477 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
478 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
479     pages, and it removes trailing spaces from listed files. It also creates
480     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
481     case, it wraps all the #defines with #ifndefs. This script should be run
482 ph10 111 before "make dist".
483 ph10 123
484 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
485     with Unicode property support.
486 ph10 123
487     (a) For a maximizing quantifier, if the two different cases of the
488     character were of different lengths in their UTF-8 codings (there are
489     some cases like this - I found 11), and the matching function had to
490 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
491     were both the same length.
492 ph10 123
493     (b) When PCRE was configured to use the heap rather than the stack for
494     recursion during matching, it was not correctly preserving the data for
495     the other case of a UTF-8 character when checking ahead for a match
496     while processing a minimizing repeat. If the check also involved
497 ph10 115 matching a wide character, but failed, corruption could cause an
498     erroneous result when trying to check for a repeat of the original
499     character.
500 ph10 123
501 ph10 116 13. Some tidying changes to the testing mechanism:
502 ph10 98
503 ph10 116 (a) The RunTest script now detects the internal link size and whether there
504     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
505 ph10 123 values substituted by "configure". (The RunGrepTest script already did
506     this for UTF-8.) The configure.ac script no longer substitutes the
507     relevant variables.
509 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
510     with length and offset values. This means that the output is different
511     for different internal link sizes. Test 2 is skipped for link sizes
512     other than 2 because of this, bypassing the problem. Unfortunately,
513     there was also a test in test 3 (the locale tests) that used /B and
514 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
515     I have added a new /Z option to pcretest that replaces the length and
516     offset values with spaces. This is now used to make test 3 independent
517 ph10 122 of link size. (Test 2 will be tidied up later.)
518 ph10 123
519     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
520 ph10 122 segmentation fault instead of returning the appropriate error message.
521 ph10 134
522 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
523 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
524     This doesn't seem right; it now treats the CRLF combination as the line
525     ending, and so does not match in that case. It's only a pattern such as ^$
526     that would hit this one: something like ^ABC$ would have failed after \r
527     and then tried again after \r\n.
529 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
530 ph10 134 in an attempt to make files that differ only in their line terminators
531     compare equal. This works on Linux.
532 ph10 142
533 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
534     as it exited. This is now fixed, thanks to valgrind.
535 ph10 142
536 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
537 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
538     was because its rules for how to advance for /g after matching an empty
539 ph10 143 string at the end of a line did not allow for this case. They now check for
540     it specially.
541 ph10 150
542     20. pcretest is supposed to handle patterns and data of any length, by
543     extending its buffers when necessary. It was getting this wrong when the
544 ph10 147 buffer for a data line had to be extended.
545 ph10 150
546 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
547 ph10 150 CRLF as a newline sequence.
548 ph10 152
549 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
550 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
551     I have nevertheless tidied it up.
552 ph10 111
553 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
554 ph10 123
555 ph10 153 24. Added a man page for pcre-config.
556 ph10 152
557 ph10 153
558 nigel 93 Version 7.0 19-Dec-06
559     ---------------------
561     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
562     moving to gcc 4.1.1.
564     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
565     sys/time.h, which is documented as needed for this function. It doesn't
566     seem to matter on Linux, but it showed up on some releases of OS X.
568     3. It seems that there are systems where bytes whose values are greater than
569     127 match isprint() in the "C" locale. The "C" locale should be the
570     default when a C program starts up. In most systems, only ASCII printing
571     characters match isprint(). This difference caused the output from pcretest
572     to vary, making some of the tests fail. I have changed pcretest so that:
574     (a) When it is outputting text in the compiled version of a pattern, bytes
575     other than 32-126 are always shown as hex escapes.
577     (b) When it is outputting text that is a matched part of a subject string,
578     it does the same, unless a different locale has been set for the match
579     (using the /L modifier). In this case, it uses isprint() to decide.
581     4. Fixed a major bug that caused incorrect computation of the amount of memory
582     required for a compiled pattern when options that changed within the
583     pattern affected the logic of the preliminary scan that determines the
584     length. The relevant options are -x, and -i in UTF-8 mode. The result was
585     that the computed length was too small. The symptoms of this bug were
586     either the PCRE error "internal error: code overflow" from pcre_compile(),
587     or a glibc crash with a message such as "pcretest: free(): invalid next
588     size (fast)". Examples of patterns that provoked this bug (shown in
589     pcretest format) are:
591     /(?-x: )/x
592     /(?x)(?-x: \s*#\s*)/
593     /((?i)[\x{c0}])/8
594     /(?i:[\x{c0}])/8
596     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
597     is now done differently.
599     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
600     wrapper classes; (b) implement a new function in the C++ scanner that is
601     more efficient than the old way of doing things because it avoids levels of
602     recursion in the regex matching; (c) add a paragraph to the documentation
603     for the FullMatch() function.
605     6. The escape sequence \n was being treated as whatever was defined as
606     "newline". Not only was this contrary to the documentation, which states
607     that \n is character 10 (hex 0A), but it also went horribly wrong when
608     "newline" was defined as CRLF. This has been fixed.
610     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
611     was being set to -1 for the "end of line" case (supposedly a value that no
612     character can have). Though this value is never used (the check for end of
613     line is "zero bytes in current character"), it caused compiler complaints.
614     I've changed it to 0xffffffff.
616     8. In pcre_version.c, the version string was being built by a sequence of
617     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
618     string (as it is for production releases) called a macro with an empty
619     argument. The C standard says the result of this is undefined. The gcc
620     compiler treats it as an empty string (which was what was wanted) but it is
621     reported that Visual C gives an error. The source has been hacked around to
622     avoid this problem.
624     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
625     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
626     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
627     of them did).
629     10. Originally, pcretest opened its input and output without "b"; then I was
630     told that "b" was needed in some environments, so it was added for release
631     5.0 to both the input and output. (It makes no difference on Unix-like
632     systems.) Later I was told that it is wrong for the input on Windows. I've
633     now abstracted the modes into two macros, to make it easier to fiddle with
634     them, and removed "b" from the input mode under Windows.
636     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
638     12. Added -help and --help to pcretest as an official way of being reminded
639     of the options.
641     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
642     and pcrecpp.cc because they annoy compilers at high warning levels.
644     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
646     15. Fixed an occurrence of == in configure.ac that should have been = (shell
647     scripts are not C programs :-) and which was not noticed because it works
648     on Linux.
650     16. pcretest is supposed to handle any length of pattern and data line (as one
651     line or as a continued sequence of lines) by extending its input buffer if
652     necessary. This feature was broken for very long pattern lines, leading to
653     a string of junk being passed to pcre_compile() if the pattern was longer
654     than about 50K.
656     17. I have done a major re-factoring of the way pcre_compile() computes the
657     amount of memory needed for a compiled pattern. Previously, there was code
658     that made a preliminary scan of the pattern in order to do this. That was
659     OK when PCRE was new, but as the facilities have expanded, it has become
660     harder and harder to keep it in step with the real compile phase, and there
661     have been a number of bugs (see for example, 4 above). I have now found a
662     cunning way of running the real compile function in a "fake" mode that
663     enables it to compute how much memory it would need, while actually only
664     ever using a few hundred bytes of working memory and without too many
665     tests of the mode. This should make future maintenance and development
666     easier. A side effect of this work is that the limit of 200 on the nesting
667     depth of parentheses has been removed (though this was never a serious
668     limitation, I suspect). However, there is a downside: pcre_compile() now
669     runs more slowly than before (30% or more, depending on the pattern). I
670     hope this isn't a big issue. There is no effect on runtime performance.
672     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
673     newline (only possible for the last line of a file) and it was a
674     pattern that set a locale (followed by /Lsomething), pcretest crashed.
676     19. Added additional timing features to pcretest. (1) The -tm option now times
677     matching only, not compiling. (2) Both -t and -tm can be followed, as a
678     separate command line item, by a number that specifies the number of
679     repeats to use when timing. The default is 50000; this gives better
680     precision, but takes uncomfortably long for very large patterns.
682     20. Extended pcre_study() to be more clever in cases where a branch of a
683     subpattern has no definite first character. For example, (a*|b*)[cd] would
684     previously give no result from pcre_study(). Now it recognizes that the
685     first character must be a, b, c, or d.
687     21. There was an incorrect error "recursive call could loop indefinitely" if
688     a subpattern (or the entire pattern) that was being tested for matching an
689     empty string contained only one non-empty item after a nested subpattern.
690     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
691     incorrectly, because the \d was being skipped in the check.
693     22. The pcretest program now has a new pattern option /B and a command line
694     option -b, which is equivalent to adding /B to every pattern. This causes
695     it to show the compiled bytecode, without the additional information that
696     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
697     is the same as /B/I).
699     23. A new optimization is now able automatically to treat some sequences such
700     as a*b as a*+b. More specifically, if something simple (such as a character
701     or a simple class like \d) has an unlimited quantifier, and is followed by
702     something that cannot possibly match the quantified thing, the quantifier
703     is automatically "possessified".
705     24. A recursive reference to a subpattern whose number was greater than 39
706     went wrong under certain circumstances in UTF-8 mode. This bug could also
707     have affected the operation of pcre_study().
709     25. Realized that a little bit of performance could be had by replacing
710     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
712     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
714     27. Possessive quantifiers such as a++ were previously implemented by turning
715     them into atomic groups such as ($>a+). Now they have their own opcodes,
716     which improves performance. This includes the automatically created ones
717     from 23 above.
719     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
720     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
721     the first matched character to be a colon. This applied both to named and
722     numbered groups.
724     29. The ucpinternal.h header file was missing its idempotency #ifdef.
726     30. I was sent a "project" file called libpcre.a.dev which I understand makes
727     building PCRE on Windows easier, so I have included it in the distribution.
729     31. There is now a check in pcretest against a ridiculously large number being
730     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
731     loop, the loop is abandoned.
733     32. Forward references to subpatterns in conditions such as (?(2)...) where
734     subpattern 2 is defined later cause pcre_compile() to search forwards in
735     the pattern for the relevant set of parentheses. This search went wrong
736     when there were unescaped parentheses in a character class, parentheses
737     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
739     33. "Subroutine" calls and backreferences were previously restricted to
740     referencing subpatterns earlier in the regex. This restriction has now
741     been removed.
743     34. Added a number of extra features that are going to be in Perl 5.10. On the
744     whole, these are just syntactic alternatives for features that PCRE had
745     previously implemented using the Python syntax or my own invention. The
746     other formats are all retained for compatibility.
748     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
749     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
750     also .NET compatible.
752     (b) A recursion or subroutine call to a named group can now be defined as
753     (?&name) as well as (?P>name).
755     (c) A backreference to a named group can now be defined as \k<name> or
756     \k'name' as well as (?P=name). The new forms, as well as being in Perl
757     5.10, are also .NET compatible.
759     (d) A conditional reference to a named group can now use the syntax
760     (?(<name>) or (?('name') as well as (?(name).
762     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
763     groups (named and numbered) that are never evaluated inline, but can be
764     called as "subroutines" from elsewhere. In effect, the DEFINE condition
765     is always false. There may be only one alternative in such a group.
767     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
768     as the simple (?(R). The condition is true only if the most recent
769     recursion is that of the given number or name. It does not search out
770     through the entire recursion stack.
772     (g) The escape \gN or \g{N} has been added, where N is a positive or
773     negative number, specifying an absolute or relative reference.
775     35. Tidied to get rid of some further signed/unsigned compiler warnings and
776     some "unreachable code" warnings.
778     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
779     things, this adds five new scripts.
781     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
782     There were also incompatibilities regarding the handling of \Q..\E inside
783     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
784     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
786     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
787     matches an empty string, and forcibly breaks the loop. There were bugs in
788     this code in non-simple cases. For a pattern such as ^(a()*)* matched
789     against aaaa the result was just "a" rather than "aaaa", for example. Two
790     separate and independent bugs (that affected different cases) have been
791     fixed.
793     39. Refactored the code to abolish the use of different opcodes for small
794     capturing bracket numbers. This is a tidy that I avoided doing when I
795     removed the limit on the number of capturing brackets for 3.5 back in 2001.
796     The new approach is not only tidier, it makes it possible to reduce the
797     memory needed to fix the previous bug (38).
799     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
800     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
801     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
802     mode.
804     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
805     report.
807     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
808     copy construction and assignment in the C++ wrapper.
810     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
811     couple of bugs that could have given wrong results in the "--newline=crlf"
812     case.
814     44. Added a number of casts and did some reorganization of signed/unsigned int
815     variables following suggestions from Dair Grant. Also renamed the variable
816     "this" as "item" because it is a C++ keyword.
818     45. Arranged for dftables to add
820     #include "pcre_internal.h"
822     to pcre_chartables.c because without it, gcc 4.x may remove the array
823     definition from the final binary if PCRE is built into a static library and
824     dead code stripping is activated.
826     46. For an unanchored pattern, if a match attempt fails at the start of a
827     newline sequence, and the newline setting is CRLF or ANY, and the next two
828     characters are CRLF, advance by two characters instead of one.
831 nigel 91 Version 6.7 04-Jul-06
832     ---------------------
834     1. In order to handle tests when input lines are enormously long, pcretest has
835     been re-factored so that it automatically extends its buffers when
836     necessary. The code is crude, but this _is_ just a test program. The
837     default size has been increased from 32K to 50K.
839     2. The code in pcre_study() was using the value of the re argument before
840     testing it for NULL. (Of course, in any sensible call of the function, it
841     won't be NULL.)
843     3. The memmove() emulation function in pcre_internal.h, which is used on
844     systems that lack both memmove() and bcopy() - that is, hardly ever -
845     was missing a "static" storage class specifier.
847     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
848     containing an extended class (one that cannot be represented by a bitmap
849     because it contains high-valued characters or Unicode property items, e.g.
850     [\pZ]). Almost always one would set UTF-8 mode when processing such a
851     pattern, but PCRE should not loop if you do not (it no longer does).
852     [Detail: two cases were found: (a) a repeated subpattern containing an
853     extended class; (b) a recursive reference to a subpattern that followed a
854     previous extended class. It wasn't skipping over the extended class
855     correctly when UTF-8 mode was not set.]
857     5. A negated single-character class was not being recognized as fixed-length
858     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
859     compile error "lookbehind assertion is not fixed length".
861     6. The RunPerlTest auxiliary script was showing an unexpected difference
862     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
863     write a Perl script that can interpret lines of an input file either as
864     byte characters or as UTF-8, which is what "perltest" was being required to
865     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
866     can't do is switch easily at run time between having the "use utf8;" pragma
867     or not. In the end, I fudged it by using the RunPerlTest script to insert
868     "use utf8;" explicitly for the UTF-8 tests.
870     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
871     the end of the subject string, contrary to the documentation and to what
872     Perl does. This was true of both matching functions. Now it matches only at
873     the start of the subject and immediately after *internal* newlines.
875     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
876     a pointer to an int instead of a pointer to an unsigned long int. This
877     caused problems on 64-bit systems.
879     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
880     instance of the 'standard' template library not being so standard".
882     10. There was no check on the number of named subpatterns nor the maximum
883     length of a subpattern name. The product of these values is used to compute
884     the size of the memory block for a compiled pattern. By supplying a very
885     long subpattern name and a large number of named subpatterns, the size
886     computation could be caused to overflow. This is now prevented by limiting
887     the length of names to 32 characters, and the number of named subpatterns
888     to 10,000.
890     11. Subpatterns that are repeated with specific counts have to be replicated in
891     the compiled pattern. The size of memory for this was computed from the
892     length of the subpattern and the repeat count. The latter is limited to
893     65535, but there was no limit on the former, meaning that integer overflow
894     could in principle occur. The compiled length of a repeated subpattern is
895     now limited to 30,000 bytes in order to prevent this.
897     12. Added the optional facility to have named substrings with the same name.
899     13. Added the ability to use a named substring as a condition, using the
900     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
901     are numbers (not recommended). Forward references are permitted.
903     14. Added forward references in named backreferences (if you see what I mean).
905     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
906     pattern could run off the end of the subject. For example, the pattern
907     "(?s)(.{1,5})"8 did this with the subject "ab".
909     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
910     PCRE_CASELESS was set when matching characters that were quantified with ?
911     or *.
913     17. A character class other than a single negated character that had a minimum
914     but no maximum quantifier - for example [ab]{6,} - was not handled
915     correctly by pce_dfa_exec(). It would match only one character.
917     18. A valid (though odd) pattern that looked like a POSIX character
918     class but used an invalid character after [ (for example [[,abc,]]) caused
919     pcre_compile() to give the error "Failed: internal error: code overflow" or
920     in some cases to crash with a glibc free() error. This could even happen if
921     the pattern terminated after [[ but there just happened to be a sequence of
922     letters, a binary zero, and a closing ] in the memory that followed.
924     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
925     over the years. Originally (before any Unicode support), just the bottom 8
926     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
927     output from "man perlunicode" includes this:
929     The regular expression compiler produces polymorphic opcodes. That
930     is, the pattern adapts to the data and automatically switches to
931     the Unicode character scheme when presented with Unicode data--or
932     instead uses a traditional byte scheme when presented with byte
933     data.
935     Sadly, a wide octal escape does not cause a switch, and in a string with
936     no other multibyte characters, these octal escapes are treated as before.
937     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
938     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
939     Unicode string.
941     I have not perpetrated such confusion in PCRE. Up till now, it took just
942     the bottom 8 bits, as in old Perl. I have now made octal escapes with
943     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
944     translate to the appropriate multibyte character.
946     29. Applied some refactoring to reduce the number of warnings from Microsoft
947     and Borland compilers. This has included removing the fudge introduced
948     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
949     a warning about an unused variable.
951     21. PCRE has not included VT (character 0x0b) in the set of whitespace
952     characters since release 4.0, because Perl (from release 5.004) does not.
953     [Or at least, is documented not to: some releases seem to be in conflict
954     with the documentation.] However, when a pattern was studied with
955     pcre_study() and all its branches started with \s, PCRE still included VT
956     as a possible starting character. Of course, this did no harm; it just
957     caused an unnecessary match attempt.
959     22. Removed a now-redundant internal flag bit that recorded the fact that case
960     dependency changed within the pattern. This was once needed for "required
961     byte" processing, but is no longer used. This recovers a now-scarce options
962     bit. Also moved the least significant internal flag bit to the most-
963     significant bit of the word, which was not previously used (hangover from
964     the days when it was an int rather than a uint) to free up another bit for
965     the future.
967     23. Added support for CRLF line endings as well as CR and LF. As well as the
968     default being selectable at build time, it can now be changed at runtime
969     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
970     specify that it is scanning data with non-default line endings.
972     24. Changed the definition of CXXLINK to make it agree with the definition of
973     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
975     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
976     recursions. This makes a big different to stack usage for some patterns.
978     26. If a subpattern containing a named recursion or subroutine reference such
979     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
980     the space required for the compiled pattern went wrong and gave too small a
981     value. Depending on the environment, this could lead to "Failed: internal
982     error: code overflow at offset 49" or "glibc detected double free or
983     corruption" errors.
985     27. Applied patches from Google (a) to support the new newline modes and (b) to
986     advance over multibyte UTF-8 characters in GlobalReplace.
988     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
989     difference for some implementation of PCRE in some Windows version.
991     29. Added some extra testing facilities to pcretest:
993     \q<number> in a data line sets the "match limit" value
994     \Q<number> in a data line sets the "match recursion limt" value
995     -S <number> sets the stack size, where <number> is in megabytes
997     The -S option isn't available for Windows.
1000 nigel 89 Version 6.6 06-Feb-06
1001     ---------------------
1003     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1004     in pcreposix.h. I have copied the definition from pcre.h.
1006     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1007     because pcre.h is no longer a built file.
1009     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1010     not normally included in the compiled code.
1013 nigel 87 Version 6.5 01-Feb-06
1014     ---------------------
1016     1. When using the partial match feature with pcre_dfa_exec(), it was not
1017     anchoring the second and subsequent partial matches at the new starting
1018     point. This could lead to incorrect results. For example, with the pattern
1019     /1234/, partially matching against "123" and then "a4" gave a match.
1021     2. Changes to pcregrep:
1023     (a) All non-match returns from pcre_exec() were being treated as failures
1024     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1025     error message is output. Some extra information is given for the
1027     probably the only errors that are likely to be caused by users (by
1028     specifying a regex that has nested indefinite repeats, for instance).
1029     If there are more than 20 of these errors, pcregrep is abandoned.
1031     (b) A binary zero was treated as data while matching, but terminated the
1032     output line if it was written out. This has been fixed: binary zeroes
1033     are now no different to any other data bytes.
1035     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1036     used to set a locale for matching. The --locale=xxxx long option has
1037     been added (no short equivalent) to specify a locale explicitly on the
1038     pcregrep command, overriding the environment variables.
1040     (d) When -B was used with -n, some line numbers in the output were one less
1041     than they should have been.
1043     (e) Added the -o (--only-matching) option.
1045     (f) If -A or -C was used with -c (count only), some lines of context were
1046     accidentally printed for the final match.
1048     (g) Added the -H (--with-filename) option.
1050     (h) The combination of options -rh failed to suppress file names for files
1051     that were found from directory arguments.
1053     (i) Added the -D (--devices) and -d (--directories) options.
1055     (j) Added the -F (--fixed-strings) option.
1057     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1059     (l) Added the --colo(u)r option.
1061     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1062     is not present by default.
1064     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1065     items such as (?R) or (?1), when the recursion could match a number of
1066     alternatives. If it matched one of the alternatives, but subsequently,
1067     outside the recursion, there was a failure, the code tried to back up into
1068     the recursion. However, because of the way PCRE is implemented, this is not
1069     possible, and the result was an incorrect result from the match.
1071     In order to prevent this happening, the specification of recursion has
1072     been changed so that all such subpatterns are automatically treated as
1073     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1075     4. I had overlooked the fact that, in some locales, there are characters for
1076     which isalpha() is true but neither isupper() nor islower() are true. In
1077     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1078     and ordfeminine) are like this. This affected the treatment of \w and \W
1079     when they appeared in character classes, but not when they appeared outside
1080     a character class. The bit map for "word" characters is now created
1081     separately from the results of isalnum() instead of just taking it from the
1082     upper, lower, and digit maps. (Plus the underscore character, of course.)
1084     5. The above bug also affected the handling of POSIX character classes such as
1085     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1086     permanent tables. Instead, the bit maps for such a class were previously
1087     created as the appropriate unions of the upper, lower, and digit bitmaps.
1088     Now they are created by subtraction from the [[:word:]] class, which has
1089     its own bitmap.
1091     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1092     It is created by subtracting the vertical space characters (\x09, \x0a,
1093     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1094     subtraction was done in the overall bitmap for a character class, meaning
1095     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1096     be recognized. This bug has been fixed.
1098     7. Patches from the folks at Google:
1100     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1101     real life, but is still worth protecting against".
1103     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1104     regular expressions".
1106     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1107     have it.
1109     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1110     "configure" and the latter not, in order to fix a problem somebody had
1111     with compiling the Arg class on HP-UX.
1113     (e) Improve the error-handling of the C++ wrapper a little bit.
1115     (f) New tests for checking recursion limiting.
1117     8. The pcre_memmove() function, which is used only if the environment does not
1118     have a standard memmove() function (and is therefore rarely compiled),
1119     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1120     returning a result (though PCRE never actually uses the result).
1122     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1123     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1124     returned instead of calling malloc() with an overflowing number that would
1125     most likely cause subsequent chaos.
1127     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1129     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1130     with this option is matched, the nmatch and pmatch options of regexec() are
1131     ignored.
1133     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1134     provided in case anyone wants to the the POSIX interface with UTF-8
1135     strings.
1137     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1138     C++ linking (needed for some HP-UX environments).
1140     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1141     (unused parameter) and in the pcre_printint() function (omitted "default"
1142     switch label when the default is to do nothing).
1144     15. Added some code to make it possible, when PCRE is compiled as a C++
1145     library, to replace subject pointers for pcre_exec() with a smart pointer
1146     class, thus making it possible to process discontinuous strings.
1148     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1149     much the same function. They were added by different people who were trying
1150     to make PCRE easy to compile on non-Unix systems. It has been suggested
1151     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1152     for compiling on Windows systems. I have therefore replaced it with
1153     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1154     defaults to "extern" for C or "extern C" for C++, which works fine on
1155     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1156     SCOPE with something explicit in config.h. In addition:
1158     (a) pcreposix.h still had just "extern" instead of either of these macros;
1159     I have replaced it with PCRE_DATA_SCOPE.
1161     (b) Functions such as _pcre_xclass(), which are internal to the library,
1162     but external in the C sense, all had PCRE_EXPORT in their definitions.
1163     This is apparently wrong for the Windows case, so I have removed it.
1164     (It makes no difference on Unix-like systems.)
1166     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1167     of recursive calls to match(). This is different to MATCH_LIMIT because
1168     that limits the total number of calls to match(), not all of which increase
1169     the depth of recursion. Limiting the recursion depth limits the amount of
1170     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1171     when PCRE is compiled, and changed at run time. A patch from Google adds
1172     this functionality to the C++ interface.
1174     18. Changes to the handling of Unicode character properties:
1176     (a) Updated the table to Unicode 4.1.0.
1178     (b) Recognize characters that are not in the table as "Cn" (undefined).
1180     (c) I revised the way the table is implemented to a much improved format
1181     which includes recognition of ranges. It now supports the ranges that
1182     are defined in UnicodeData.txt, and it also amalgamates other
1183     characters into ranges. This has reduced the number of entries in the
1184     table from around 16,000 to around 3,000, thus reducing its size
1185     considerably. I realized I did not need to use a tree structure after
1186     all - a binary chop search is just as efficient. Having reduced the
1187     number of entries, I extended their size from 6 bytes to 8 bytes to
1188     allow for more data.
1190     (d) Added support for Unicode script names via properties such as \p{Han}.
1192     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1193     matching that character.
1195     20. When matching a repeated Unicode property with a minimum greater than zero,
1196     (for example \pL{2,}), PCRE could look past the end of the subject if it
1197     reached it while seeking the minimum number of characters. This could
1198     happen only if some of the characters were more than one byte long, because
1199     there is a check for at least the minimum number of bytes.
1201     21. Refactored the implementation of \p and \P so as to be more general, to
1202     allow for more different types of property in future. This has changed the
1203     compiled form incompatibly. Anybody with saved compiled patterns that use
1204     \p or \P will have to recompile them.
1206     22. Added "Any" and "L&" to the supported property types.
1208     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1209     but give a compile time error if the value is greater than 0xff.
1211     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1212     accidentally not being installed or uninstalled.
1214     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1215     made were to insert the current release number. This seemed silly, because
1216     it made things harder for people building PCRE on systems that don't run
1217     "configure". I have turned pcre.h into a distributed file, no longer built
1218     by "configure", with the version identification directly included. There is
1219     no longer a pcre.h.in file.
1221     However, this change necessitated a change to the pcre-config script as
1222     well. It is built from pcre-config.in, and one of the substitutions was the
1223     release number. I have updated configure.ac so that ./configure now finds
1224     the release number by grepping pcre.h.
1226     26. Added the ability to run the tests under valgrind.
1229 nigel 85 Version 6.4 05-Sep-05
1230     ---------------------
1232     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1233     "--" to be printed when multiple files were scanned, even when none of the
1234     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1235     consider it to be a bug, and have restored the previous behaviour.
1237     2. A couple of code tidies to get rid of compiler warnings.
1239     3. The pcretest program used to cheat by referring to symbols in the library
1240     whose names begin with _pcre_. These are internal symbols that are not
1241     really supposed to be visible externally, and in some environments it is
1242     possible to suppress them. The cheating is now confined to including
1243     certain files from the library's source, which is a bit cleaner.
1245     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1246     file's purpose clearer.
1248     5. Reorganized pcre_ucp_findchar().
1251 nigel 83 Version 6.3 15-Aug-05
1252     ---------------------
1254     1. The file libpcre.pc.in did not have general read permission in the tarball.
1256     2. There were some problems when building without C++ support:
1258     (a) If C++ support was not built, "make install" and "make test" still
1259     tried to test it.
1261     (b) There were problems when the value of CXX was explicitly set. Some
1262     changes have been made to try to fix these, and ...
1264     (c) --disable-cpp can now be used to explicitly disable C++ support.
1266     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1267     backslash in a target when C++ was disabled. This confuses some
1268     versions of "make", apparently. Using an intermediate variable solves
1269     this. (Same for CPP_LOBJ.)
1271     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1272     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1273     necessary on certain architectures.
1275     4. Added a setting of -export-symbols-regex to the link command to remove
1276     those symbols that are exported in the C sense, but actually are local
1277     within the library, and not documented. Their names all begin with
1278     "_pcre_". This is not a perfect job, because (a) we have to except some
1279     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1280     available (and never for static libraries). I have made a note to try to
1281     find a way round (a) in the future.
1284 nigel 81 Version 6.2 01-Aug-05
1285     ---------------------
1287     1. There was no test for integer overflow of quantifier values. A construction
1288     such as {1111111111111111} would give undefined results. What is worse, if
1289     a minimum quantifier for a parenthesized subpattern overflowed and became
1290     negative, the calculation of the memory size went wrong. This could have
1291     led to memory overwriting.
1293     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1295     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1296     operating environments where this matters.
1298     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1299     PCRE options from within the C++ wrapper.
1301     5. Named capturing subpatterns were not being correctly counted when a pattern
1302     was compiled. This caused two problems: (a) If there were more than 100
1303     such subpatterns, the calculation of the memory needed for the whole
1304     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1305     back references of the form \12, where the number was greater than 9, were
1306     not recognized as back references, even though there were sufficient
1307     previous subpatterns.
1309     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1310     versions of gcc, e.g. 2.95.4.
1313 nigel 79 Version 6.1 21-Jun-05
1314     ---------------------
1316     1. There was one reference to the variable "posix" in pcretest.c that was not
1317     surrounded by "#if !defined NOPOSIX".
1319     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1320     the cross-check on the old pcre_info() function, for the benefit of the
1321     cut-down version of PCRE that is currently imported into Exim.
1323     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1324     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1325     patterns that start (?i) but I don't think that matters. The use of (?i) is
1326     just an example; this all applies to the other options as well.
1328     4. Since libtool seems to echo the compile commands it is issuing, the output
1329     from "make" can be reduced a bit by putting "@" in front of each libtool
1330     compile command.
1332     5. Patch from the folks at Google for configure.in to be a bit more thorough
1333     in checking for a suitable C++ installation before trying to compile the
1334     C++ stuff. This should fix a reported problem when a compiler was present,
1335     but no suitable headers.
1337     6. The man pages all had just "PCRE" as their title. I have changed them to
1338     be the relevant file name. I have also arranged that these names are
1339     retained in the file doc/pcre.txt, which is a concatenation in text format
1340     of all the man pages except the little individual ones for each function.
1342     7. The NON-UNIX-USE file had not been updated for the different set of source
1343     files that come with release 6. I also added a few comments about the C++
1344     wrapper.
1347 nigel 77 Version 6.0 07-Jun-05
1348     ---------------------
1350     1. Some minor internal re-organization to help with my DFA experiments.
1352     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1353     didn't matter for the library itself when fully configured, but did matter
1354     when compiling without UCP support, or within Exim, where the ucp files are
1355     not imported.
1357     3. Refactoring of the library code to split up the various functions into
1358     different source modules. The addition of the new DFA matching code (see
1359     below) to a single monolithic source would have made it really too
1360     unwieldy, quite apart from causing all the code to be include in a
1361     statically linked application, when only some functions are used. This is
1362     relevant even without the DFA addition now that patterns can be compiled in
1363     one application and matched in another.
1365     The downside of splitting up is that there have to be some external
1366     functions and data tables that are used internally in different modules of
1367     the library but which are not part of the API. These have all had their
1368     names changed to start with "_pcre_" so that they are unlikely to clash
1369     with other external names.
1371     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1372     a different (DFA) algorithm. Although it is slower than the original
1373     function, it does have some advantages for certain types of matching
1374     problem.
1376     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1377     including restarting after a partial match.
1379     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1380     defined when compiling for Windows was sent to me. I have put it into the
1381     code, though I have no means of testing or verifying it.
1383     7. Added the pcre_refcount() auxiliary function.
1385     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1386     match before or at the first newline in the subject string. In pcretest,
1387     the /f option on a pattern can be used to set this.
1389     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1390     would behave wrongly. This has been present in PCRE since release 4.0.
1392     10. A number of changes to the pcregrep command:
1394     (a) Refactored how -x works; insert ^(...)$ instead of setting
1395     PCRE_ANCHORED and checking the length, in preparation for adding
1396     something similar for -w.
1398     (b) Added the -w (match as a word) option.
1400     (c) Refactored the way lines are read and buffered so as to have more
1401     than one at a time available.
1403     (d) Implemented a pcregrep test script.
1405     (e) Added the -M (multiline match) option. This allows patterns to match
1406     over several lines of the subject. The buffering ensures that at least
1407     8K, or the rest of the document (whichever is the shorter) is available
1408     for matching (and similarly the previous 8K for lookbehind assertions).
1410     (f) Changed the --help output so that it now says
1412     -w, --word-regex(p)
1414     instead of two lines, one with "regex" and the other with "regexp"
1415     because that confused at least one person since the short forms are the
1416     same. (This required a bit of code, as the output is generated
1417     automatically from a table. It wasn't just a text change.)
1419     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1420     option but starts with a hyphen. Could be a pattern or a path name
1421     starting with a hyphen, for instance.
1423     (h) "-" can be given as a file name to represent stdin.
1425     (i) When file names are being printed, "(standard input)" is used for
1426     the standard input, for compatibility with GNU grep. Previously
1427     "<stdin>" was used.
1429     (j) The option --label=xxx can be used to supply a name to be used for
1430     stdin when file names are being printed. There is no short form.
1432     (k) Re-factored the options decoding logic because we are going to add
1433     two more options that take data. Such options can now be given in four
1434     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1436     (l) Added the -A, -B, and -C options for requesting that lines of context
1437     around matches be printed.
1439     (m) Added the -L option to print the names of files that do not contain
1440     any matching lines, that is, the complement of -l.
1442     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1443     continue to scan other files.
1445     (o) The -s option was incorrectly implemented. For compatibility with other
1446     greps, it now suppresses the error message for a non-existent or non-
1447     accessible file (but not the return code). There is a new option called
1448     -q that suppresses the output of matching lines, which was what -s was
1449     previously doing.
1451     (p) Added --include and --exclude options to specify files for inclusion
1452     and exclusion when recursing.
1454     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1455     Hopefully, it now does.
1457     12. Missing cast in pcre_study().
1459     13. Added an "uninstall" target to the makefile.
1461     14. Replaced "extern" in the function prototypes in Makefile.in with
1462     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1463     world, but is set differently for Windows.
1465     15. Added a second compiling function called pcre_compile2(). The only
1466     difference is that it has an extra argument, which is a pointer to an
1467     integer error code. When there is a compile-time failure, this is set
1468     non-zero, in addition to the error test pointer being set to point to an
1469     error message. The new argument may be NULL if no error number is required
1470     (but then you may as well call pcre_compile(), which is now just a
1471     wrapper). This facility is provided because some applications need a
1472     numeric error indication, but it has also enabled me to tidy up the way
1473     compile-time errors are handled in the POSIX wrapper.
1475     16. Added VPATH=.libs to the makefile; this should help when building with one
1476     prefix path and installing with another. (Or so I'm told by someone who
1477     knows more about this stuff than I do.)
1479     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1480     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1481     match everything, including newlines. This is not POSIX-compatible, but
1482     somebody wanted the feature. From pcretest it can be activated by using
1483     both the P and the s flags.
1485     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1487     19. libpcre.pc was being incorrectly installed as executable.
1489     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1490     it now also looks for '\r' so that it will work unmodified on Windows.
1492     21. Added Google's contributed C++ wrapper to the distribution.
1494     22. Added some untidy missing memory free() calls in pcretest, to keep
1495     Electric Fence happy when testing.
1499 nigel 75 Version 5.0 13-Sep-04
1500     ---------------------
1502     1. Internal change: literal characters are no longer packed up into items
1503     containing multiple characters in a single byte-string. Each character
1504     is now matched using a separate opcode. However, there may be more than one
1505     byte in the character in UTF-8 mode.
1507     2. The pcre_callout_block structure has two new fields: pattern_position and
1508     next_item_length. These contain the offset in the pattern to the next match
1509     item, and its length, respectively.
1511     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1512     insertion of callouts before each pattern item. Added the /C option to
1513     pcretest to make use of this.
1515     4. On the advice of a Windows user, the lines
1517     #if defined(_WIN32) || defined(WIN32)
1518     _setmode( _fileno( stdout ), 0x8000 );
1519     #endif /* defined(_WIN32) || defined(WIN32) */
1521     have been added to the source of pcretest. This apparently does useful
1522     magic in relation to line terminators.
1524     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1525     for the benefit of those environments where the "b" makes a difference.
1527     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1528     to know about it. I have put a hack into configure.in that adds in code
1529     to set GCC=yes if CC=icc. This seems to end up at a point in the
1530     generated configure script that is early enough to affect the setting of
1531     compiler options, which is what is needed, but I have no means of testing
1532     whether it really works. (The user who reported this had patched the
1533     generated configure script, which of course I cannot do.)
1535     LATER: After change 22 below (new libtool files), the configure script
1536     seems to know about icc (and also ecc). Therefore, I have commented out
1537     this hack in configure.in.
1539     7. Added support for pkg-config (2 patches were sent in).
1541     8. Negated POSIX character classes that used a combination of internal tables
1542     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1543     [[:^ascii]]. Typically, they would match almost any characters. The other
1544     POSIX classes were not broken in this way.
1546     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1547     to find the match, as PCRE was deluded into thinking that the match had to
1548     start at the start point or following a newline. The same bug applied to
1549     patterns with negative forward assertions or any backward assertions
1550     preceding ".*" at the start, unless the pattern required a fixed first
1551     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1553     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1554     starting at the last subject character, bytes beyond the end of the subject
1555     string were read.
1557     11. Renamed the variable "class" as "classbits" to make life easier for C++
1558     users. (Previously there was a macro definition, but it apparently wasn't
1559     enough.)
1561     12. Added the new field "tables" to the extra data so that tables can be passed
1562     in at exec time, or the internal tables can be re-selected. This allows
1563     a compiled regex to be saved and re-used at a later time by a different
1564     program that might have everything at different addresses.
1566     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1567     -R library as well as a -L library.
1569     14. The debugging options of pcretest (-d on the command line or D on a
1570     pattern) showed incorrect output for anything following an extended class
1571     that contained multibyte characters and which was followed by a quantifier.
1573     15. Added optional support for general category Unicode character properties
1574     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1575     support. It adds about 90K to the size of the library. The meanings of the
1576     inbuilt class escapes such as \d and \s have NOT been changed.
1578     16. Updated pcredemo.c to include calls to free() to release the memory for the
1579     compiled pattern.
1581     17. The generated file chartables.c was being created in the source directory
1582     instead of in the building directory. This caused the build to fail if the
1583     source directory was different from the building directory, and was
1584     read-only.
1586     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1587     file. No doubt somebody will tell me if they don't make sense... Also added
1588     Dan Mooney's comments about building on OpenVMS.
1590     19. Added support for partial matching via the PCRE_PARTIAL option for
1591     pcre_exec() and the \P data escape in pcretest.
1593     20. Extended pcretest with 3 new pattern features:
1595     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1596     write the compiled pattern to the file whose name is "rest-of-line".
1597     This is a straight binary dump of the data, with the saved pointer to
1598     the character tables forced to be NULL. The study data, if any, is
1599     written too. After writing, pcretest reads a new pattern.
1601     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1602     compiled pattern from the given file. There must not be any
1603     occurrences of "<" in the file name (pretty unlikely); if there are,
1604     pcretest will instead treat the initial "<" as a pattern delimiter.
1605     After reading in the pattern, pcretest goes on to read data lines as
1606     usual.
1608     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1609     and 16-bit fields in a compiled pattern, to simulate a pattern that
1610     was compiled on a host of opposite endianness.
1612     21. The pcre-exec() function can now cope with patterns that were compiled on
1613     hosts of opposite endianness, with this restriction:
1615     As for any compiled expression that is saved and used later, the tables
1616     pointer field cannot be preserved; the extra_data field in the arguments
1617     to pcre_exec() should be used to pass in a tables address if a value
1618     other than the default internal tables were used at compile time.
1620     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1621     now diagnosed as an error. Previously, most of the time, a negative number
1622     would have been treated as zero, but if in addition "ovector" was passed as
1623     NULL, a crash could occur.
1625     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1626     new versions from the libtool 1.5 distribution (the last one is a copy of
1627     a file called libtool.m4). This seems to have fixed the need to patch
1628     "configure" to support Darwin 1.3 (which I used to do). However, I still
1629     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1630     workstation).
1632     24. Changed the PCRE licence to be the more standard "BSD" licence.
1635 nigel 73 Version 4.5 01-Dec-03
1636     ---------------------
1638     1. There has been some re-arrangement of the code for the match() function so
1639     that it can be compiled in a version that does not call itself recursively.
1640     Instead, it keeps those local variables that need separate instances for
1641     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1642     needs to "recurse". Keeping track of where control must go is done by means
1643     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1644     hide most of the details from the main code, and operates only if
1645     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1646     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1647     operating.
1649     To make it easier for callers to provide specially tailored get/free
1650     functions for this usage, two new functions, pcre_stack_malloc, and
1651     pcre_stack_free, are used. They are always called in strict stacking order,
1652     and the size of block requested is always the same.
1654     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1655     PCRE has been compiled to use the stack or the heap for recursion. The
1656     -C option of pcretest uses this to show which version is compiled.
1658     A new data escape \S, is added to pcretest; it causes the amounts of store
1659     obtained and freed by both kinds of malloc/free at match time to be added
1660     to the output.
1662     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1663     what's available on my current Linux desktop machine.
1665     3. When matching a UTF-8 string, the test for a valid string at the start has
1666     been extended. If start_offset is not zero, PCRE now checks that it points
1667     to a byte that is the start of a UTF-8 character. If not, it returns
1668     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1669     this is necessary because there may be backward assertions in the pattern.
1670     When matching the same subject several times, it may save resources to use
1671     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1673     4. The code for checking the validity of UTF-8 strings has been tightened so
1674     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1675     containing "overlong sequences".
1677     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1678     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1679     should have been "&", but it just so happened that all the cases this let
1680     through by mistake were picked up later in the function.
1682     6. I had used a variable called "isblank" - this is a C99 function, causing
1683     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1685     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1686     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1687     so the version is shown; (c) stop "make test" echoing "./RunTest".
1689     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1691     9. The prototype for memmove() for systems that don't have it was using
1692     size_t, but the inclusion of the header that defines size_t was later. I've
1693     moved the #includes for the C headers earlier to avoid this.
1695     10. Added some adjustments to the code to make it easier to compiler on certain
1696     special systems:
1698     (a) Some "const" qualifiers were missing.
1699     (b) Added the macro EXPORT before all exported functions; by default this
1700     is defined to be empty.
1701     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1702     that it reads its output file name as an argument instead of writing
1703     to the standard output and assuming this can be redirected.
1705     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1706     class containing characters with values greater than 255, PCRE compilation
1707     went into a loop.
1709     12. A recursive reference to a subpattern that was within another subpattern
1710     that had a minimum quantifier of zero caused PCRE to crash. For example,
1711     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1712     recursion. If the recursively-called subpattern itself had a zero repeat,
1713     that was OK.
1715     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1716     buffer into which it was copied (for escape processing) was still set at
1717     1024, so long lines caused crashes.
1719     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1720     "internal error: code overflow...". This applied to any character class
1721     that was followed by a possessive quantifier.
1723     15. Modified the Makefile to add libpcre.la as a prerequisite for
1724     libpcreposix.la because I was told this is needed for a parallel build to
1725     work.
1727     16. If a pattern that contained .* following optional items at the start was
1728     studied, the wrong optimizing data was generated, leading to matching
1729     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1730     matching string must start with a or b or c. The correct conclusion for
1731     this pattern is that a match can start with any character.
1734 nigel 71 Version 4.4 13-Aug-03
1735     ---------------------
1737     1. In UTF-8 mode, a character class containing characters with values between
1738     127 and 255 was not handled correctly if the compiled pattern was studied.
1739     In fixing this, I have also improved the studying algorithm for such
1740     classes (slightly).
1742     2. Three internal functions had redundant arguments passed to them. Removal
1743     might give a very teeny performance improvement.
1745     3. Documentation bug: the value of the capture_top field in a callout is *one
1746     more than* the number of the hightest numbered captured substring.
1748     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1749     in incorrectly linking with a previously installed version. They now link
1750     explicitly with libpcre.la.
1752     5. configure.in no longer needs to recognize Cygwin specially.
1754     6. A problem in pcre.in for Windows platforms is fixed.
1756     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1757     pcretest, it used to include the size of the study block as part of its
1758     output. Unfortunately, the structure contains a field that has a different
1759     size on different hardware architectures. This meant that the tests that
1760     showed this size failed. As the block is currently always of a fixed size,
1761     this information isn't actually particularly useful in pcretest output, so
1762     I have just removed it.
1764     8. Three pre-processor statements accidentally did not start in column 1.
1765     Sadly, there are *still* compilers around that complain, even though
1766     standard C has not required this for well over a decade. Sigh.
1768     9. In pcretest, the code for checking callouts passed small integers in the
1769     callout_data field, which is a void * field. However, some picky compilers
1770     complained about the casts involved for this on 64-bit systems. Now
1771     pcretest passes the address of the small integer instead, which should get
1772     rid of the warnings.
1774     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1775     both compile and run time, and gives an error if an invalid UTF-8 sequence
1776     is found. There is a option for disabling this check in cases where the
1777     string is known to be correct and/or the maximum performance is wanted.
1779     11. In response to a bug report, I changed one line in Makefile.in from
1781     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1782     to
1783     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1785     to look similar to other lines, but I have no way of telling whether this
1786     is the right thing to do, as I do not use Windows. No doubt I'll get told
1787     if it's wrong...
1790 nigel 69 Version 4.3 21-May-03
1791     ---------------------
1793     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1794     Makefile.
1796     2. Some refactoring to improve the quality of the code:
1798     (i) The utf8_table... variables are now declared "const".
1800     (ii) The code for \cx, which used the "case flipping" table to upper case
1801     lower case letters, now just substracts 32. This is ASCII-specific,
1802     but the whole concept of \cx is ASCII-specific, so it seems
1803     reasonable.
1805     (iii) PCRE was using its character types table to recognize decimal and
1806     hexadecimal digits in the pattern. This is silly, because it handles
1807     only 0-9, a-f, and A-F, but the character types table is locale-
1808     specific, which means strange things might happen. A private
1809     table is now used for this - though it costs 256 bytes, a table is
1810     much faster than multiple explicit tests. Of course, the standard
1811     character types table is still used for matching digits in subject
1812     strings against \d.
1814     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1815     ending in _t are). So I've renamed it as ESC_tee.
1817     3. The first argument for regexec() in the POSIX wrapper should have been
1818     defined as "const".
1820     4. Changed pcretest to use malloc() for its buffers so that they can be
1821     Electric Fenced for debugging.
1823     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1824     to read one or more bytes before the start of the subject string. Often this
1825     had no effect on PCRE's behaviour, but in some circumstances it could
1826     provoke a segmentation fault.
1828     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1829     to try to read one or more bytes before the start of the subject string.
1831     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1832     UTF-8 support could misbehave in various ways if the subject string
1833     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1834     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1835     back over UTF-8 characters.)
1838 nigel 67 Version 4.2 14-Apr-03
1839     ---------------------
1841     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1843     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1844     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1845     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1846     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1847     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1848     and BUILD_EXEEXT
1849     Note: automatic setting of the BUILD variables is not yet working
1850     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1851     compile-time but not at link-time
1852     [LINK]: use for linking executables only
1853     make different versions for Windows and non-Windows
1854     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1855     libraries
1856     [LINK_FOR_BUILD]: new variable
1857     [OBJEXT]: use throughout
1858     [EXEEXT]: use throughout
1859     <winshared>: new target
1860     <wininstall>: new target
1861     <dftables.o>: use native compiler
1862     <dftables>: use native linker
1863     <install>: handle Windows platform correctly
1864     <clean>: ditto
1865     <check>: ditto
1866     copy DLL to top builddir before testing
1868     As part of these changes, -no-undefined was removed again. This was reported
1869     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1870     in any case.
1872     3. Some tidies to get rid of compiler warnings:
1874     . In the match_data structure, match_limit was an unsigned long int, whereas
1875     match_call_count was an int. I've made them both unsigned long ints.
1877     . In pcretest the fact that a const uschar * doesn't automatically cast to
1878     a void * provoked a warning.
1880     . Turning on some more compiler warnings threw up some "shadow" variables
1881     and a few more missing casts.
1883     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1884     option, a class that contained a single character with a value between 128
1885     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1887     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1888     option, a class that contained several characters, but with at least one
1889     whose value was between 128 and 255 caused PCRE to crash.
1892 nigel 65 Version 4.1 12-Mar-03
1893     ---------------------
1894 nigel 63
1895 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
1896     needed, and a string in dftables.c that was longer than standard compilers are
1897     required to support.
1899     2. Compiling with Sun's compiler found a few more places where the code could
1900     be tidied up in order to avoid warnings.
1902     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1903     first of these names is deprecated in the latest Autoconf in favour of the name
1904     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1905     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1906     analogy I have changed it to CFLAGS_FOR_BUILD.
1908     4. Added -no-undefined to the linking command in the Makefile, because this is
1909     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1910     linking step for the pcreposix library.
1912     5. PCRE was failing to diagnose the case of two named groups with the same
1913     name.
1915     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1916     literal character that is needed in the subject for a match, and scans along to
1917     ensure that it is present before embarking on the full matching process. This
1918     saves time in cases of nested unlimited repeats that are never going to match.
1919     Problem: the scan can take a lot of time if the subject is very long (e.g.
1920     megabytes), thus penalizing straightforward matches. It is now done only if the
1921     amount of subject to be scanned is less than 1000 bytes.
1923     7. A lesser problem with the same optimization is that it was recording the
1924     first character of an anchored pattern as "needed", thus provoking a search
1925     right along the subject, even when the first match of the pattern was going to
1926     fail. The "needed" character is now not set for anchored patterns, unless it
1927     follows something in the pattern that is of non-fixed length. Thus, it still
1928     fulfils its original purpose of finding quick non-matches in cases of nested
1929     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1932     Version 4.0 17-Feb-03
1933     ---------------------
1935 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
1936     extended to the end of string, PCRE compiled incorrect data. This could lead to
1937     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1939     2. Moved to autoconf 2.53 and libtool 1.4.2.
1941     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1942     the special perltest8 script is no longer needed - all the tests can be run
1943     from a single perltest script.
1945     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1946     by \s. It has now been removed in PCRE. This means it isn't recognized as
1947     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1948     class [:space:] *does* include VT, thereby creating a mess.
1950     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1951     space and tab.
1953     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1954     its new features into the main test script, reducing the number of scripts.
1956     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1957     were backward compatible, and made the (?i) apply to the whole pattern, as if
1958     /i were given. Now it behaves more logically, and applies the option setting
1959     only to what follows. PCRE has been changed to follow suit. However, if it
1960     finds options settings right at the start of the pattern, it extracts them into
1961     the global options, as before. Thus, they show up in the info data.
1963     8. Added support for the \Q...\E escape sequence. Characters in between are
1964     treated as literals. This is slightly different from Perl in that $ and @ are
1965     also handled as literals inside the quotes. In Perl, they will cause variable
1966     interpolation. Note the following examples:
1968     Pattern PCRE matches Perl matches
1970     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1971     \Qabc\$xyz\E abc\$xyz abc\$xyz
1972     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1974     For compatibility with Perl, \Q...\E sequences are recognized inside character
1975     classes as well as outside them.
1977     9. Re-organized 3 code statements in pcretest to avoid "overflow in
1978     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1979     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1980     signed/unsigned warnings.
1982     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1983     option for pcretest, so I've replaced it by a simple function that does just
1984     that job.
1986     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1987     "pcregrep -".
1989     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1990     Java package. This provides some syntactic sugar for simple cases of what my
1991     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1992     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1993     item, you can use this simplified notation. Note that only makes sense with
1994     greedy quantifiers. Consequently, the use of the possessive quantifier forces
1995     greediness, whatever the setting of the PCRE_UNGREEDY option.
1997     13. A change of greediness default within a pattern was not taking effect at
1998     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1999     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2000     was abstracted outside.
2002     14. PCRE now supports the \G assertion. It is true when the current matching
2003     position is at the start point of the match. This differs from \A when the
2004     starting offset is non-zero. Used with the /g option of pcretest (or similar
2005     code), it works in the same way as it does for Perl's /g option. If all
2006     alternatives of a regex begin with \G, the expression is anchored to the start
2007     match position, and the "anchored" flag is set in the compiled expression.
2009     15. Some bugs concerning the handling of certain option changes within patterns
2010     have been fixed. These applied to options other than (?ims). For example,
2011     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2012     been the other way round. Some of this was related to change 7 above.
2014     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2015     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2016     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2017     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2019     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2020     mode. Unlike ".", it always matches newline, whatever the setting of
2021     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2022     assertions. Perl allows it, but it doesn't (in general) work because it can't
2023     calculate the length of the lookbehind. At least, that's the case for Perl
2024     5.8.0 - I've been told they are going to document that it doesn't work in
2025     future.
2027     18. Added an error diagnosis for escapes that PCRE does not support: these are
2028     \L, \l, \N, \P, \p, \U, \u, and \X.
2030     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2031     reading past the end of the pattern in cases such as /[abcd/.
2033     20. PCRE was getting more memory than necessary for patterns with classes that
2034     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2036     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2037     compiling PCRE for use with Virtual Pascal.
2039     22. Small fix to the Makefile to make it work properly if the build is done
2040     outside the source tree.
2042     23. Added a new extension: a condition to go with recursion. If a conditional
2043     subpattern starts with (?(R) the "true" branch is used if recursion has
2044     happened, whereas the "false" branch is used only at the top level.
2046     24. When there was a very long string of literal characters (over 255 bytes
2047     without UTF support, over 250 bytes with UTF support), the computation of how
2048     much memory was required could be incorrect, leading to segfaults or other
2049     strange effects.
2051     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2052     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2053     there was a subsequent back reference to those brackets. This meant that, for
2054     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2055     possible to check for precisely this case. All we can do is abandon the
2056     optimization if .* occurs inside capturing brackets when there are any back
2057     references whatsoever. (See below for a better fix that came later.)
2059     26. The handling of the optimization for finding the first character of a
2060     non-anchored pattern, and for finding a character that is required later in the
2061     match were failing in some cases. This didn't break the matching; it just
2062     failed to optimize when it could. The way this is done has been re-implemented.
2064     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2066     28. Added a new feature that provides some of the functionality that Perl
2067     provides with (?{...}). The facility is termed a "callout". The way it is done
2068     in PCRE is for the caller to provide an optional function, by setting
2069     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2070     global variable. By default it is unset, which disables all calling out. To get
2071     the function called, the regex must include (?C) at appropriate points. This
2072     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2073     This provides a means of identifying different callout points. When PCRE
2074     reaches such a point in the regex, if pcre_callout has been set, the external
2075     function is called. It is provided with data in a structure called
2076     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2077     matching continues; if it returns a non-zero value, the match at the current
2078     point fails. However, backtracking will occur if possible. [This was changed
2079     later and other features added - see item 49 below.]
2081     29. pcretest is upgraded to test the callout functionality. It provides a
2082     callout function that displays information. By default, it shows the start of
2083     the match and the current position in the text. There are some new data escapes
2084     to vary what happens:
2086     \C+ in addition, show current contents of captured substrings
2087     \C- do not supply a callout function
2088     \C!n return 1 when callout number n is reached
2089     \C!n!m return 1 when callout number n is reached for the mth time
2091     30. If pcregrep was called with the -l option and just a single file name, it
2092     output "<stdin>" if a match was found, instead of the file name.
2094     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2095     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2096     pcre_exec(). This saves a malloc/free per call. The default value of
2097     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2098     when configuring.
2100     32. The default maximum size of a compiled pattern is 64K. There have been a
2101     few cases of people hitting this limit. The code now uses macros to handle the
2102     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2103     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2104     configuring. Tests 2 and 5 work only with 2-byte links because they output
2105     debugging information about compiled patterns.
2107     33. Internal code re-arrangements:
2109     (a) Moved the debugging function for printing out a compiled regex into
2110     its own source file (printint.c) and used #include to pull it into
2111     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2112     separate copies.
2114     (b) Defined the list of op-code names for debugging as a macro in
2115     internal.h so that it is next to the definition of the opcodes.
2117     (c) Defined a table of op-code lengths for simpler skipping along compiled
2118     code. This is again a macro in internal.h so that it is next to the
2119     definition of the opcodes.
2121     34. Added support for recursive calls to individual subpatterns, along the
2122     lines of Robin Houston's patch (but implemented somewhat differently).
2124     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2125     allow it to read and process whole directories in Win32. This code was
2126     contributed by Lionel Fourquaux; it has not been tested by me.
2128     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2129     used to name a group. Names consist of alphanumerics and underscores, and must
2130     be unique. Back references use the syntax (?P=name) and recursive calls use
2131     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2132     numbers. The function pcre_fullinfo() can be used after compilation to extract
2133     a name/number map. There are three relevant calls:
2135     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2136     PCRE_INFO_NAMECOUNT yields the number of entries
2137     PCRE_INFO_NAMETABLE yields a pointer to the map.
2139     The map is a vector of fixed-size entries. The size of each entry depends on
2140     the length of the longest name used. The first two bytes of each entry are the
2141     group number, most significant byte first. There follows the corresponding
2142     name, zero terminated. The names are in alphabetical order.
2144     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2145     case instead of 255. Making it the same both with and without UTF-8 support
2146     means that the same test output works with both.
2148     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2149     calling malloc() with a zero argument.
2151     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2152     optimization. I've improved things by keeping a bitmap of backreferences with
2153     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2154     fact referenced, the optimization can be applied. It is unlikely that a
2155     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2156     the match to follow \n) will appear inside brackets with a number greater than
2157     31, but if it does, any back reference > 31 suppresses the optimization.
2159     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2160     of disabling numbered capturing parentheses. Any opening parenthesis that is
2161     not followed by ? behaves as if it were followed by ?: but named parentheses
2162     can still be used for capturing (and they will acquire numbers in the usual
2163     way).
2165     41. Redesigned the return codes from the match() function into yes/no/error so
2166     that errors can be passed back from deep inside the nested calls. A malloc
2167     failure while inside a recursive subpattern call now causes the
2168     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2170     42. It is now possible to set a limit on the number of times the match()
2171     function is called in a call to pcre_exec(). This facility makes it possible to
2172     limit the amount of recursion and backtracking, though not in a directly
2173     obvious way, because the match() function is used in a number of different
2174     circumstances. The count starts from zero for each position in the subject
2175     string (for non-anchored patterns). The default limit is, for compatibility, a
2176     large number, namely 10 000 000. You can change this in two ways:
2178     (a) When configuring PCRE before making, you can use --with-match-limit=n
2179     to set a default value for the compiled library.
2181     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2182     a different value is set. See 45 below.
2184     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2186     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2187     of things that can be changed at compile time. The first argument specifies
2188     what is wanted and the second points to where the information is to be placed.
2189     The current list of available information is:
2193     The output is an integer that is set to one if UTF-8 support is available;
2194     otherwise it is set to zero.
2198     The output is an integer that it set to the value of the code that is used for
2199     newline. It is either LF (10) or CR (13).
2203     The output is an integer that contains the number of bytes used for internal
2204     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2208     The output is an integer that contains the threshold above which the POSIX
2209     interface uses malloc() for output vectors. See item 31 above.
2213     The output is an unsigned integer that contains the default limit of the number
2214     of match() calls in a pcre_exec() execution. See 42 above.
2216     44. pcretest has been upgraded by the addition of the -C option. This causes it
2217     to extract all the available output from the new pcre_config() function, and to
2218     output it. The program then exits immediately.
2220     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2221     order to support additional features. One way would have been to define
2222     pcre_exec2() (for example) with extra arguments, but this would not have been
2223     extensible, and would also have required all calls to the original function to
2224     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2225     is used for passing in "extra" data from pcre_study().
2227     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2228     contains the following fields:
2230     flags a bitmap indicating which of the following fields are set
2231     study_data opaque data from pcre_study()
2232     match_limit a way of specifying a limit on match() calls for a specific
2233     call to pcre_exec()
2234     callout_data data for callouts (see 49 below)
2236     The flag bits are also defined in pcre.h, and are
2242     The pcre_study() function now returns one of these new pcre_extra blocks, with
2243     the actual study data pointed to by the study_data field, and the
2244     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2245     before. That is, this change is entirely upwards-compatible and requires no
2246     change to existing code.
2248     If you want to pass in additional data to pcre_exec(), you can either place it
2249     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2250     block.
2252     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2253     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2254     times with different match limits, until it finds the minimum value needed for
2255     pcre_exec() to complete. The value is then output. This can be instructive; for
2256     most simple matches the number is quite small, but for pathological cases it
2257     gets very large very quickly.
2259     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2260     returns the size of the data block pointed to by the study_data field in a
2261     pcre_extra block, that is, the value that was passed as the argument to
2262     pcre_malloc() when PCRE was getting memory in which to place the information
2263     created by pcre_study(). The fourth argument should point to a size_t variable.
2264     pcretest has been extended so that this information is shown after a successful
2265     pcre_study() call when information about the compiled regex is being displayed.
2267     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2268     because what follows is always an absolute path. (Later: it turns out that this
2269     is more than cosmetic for MinGW, because it doesn't like empty path
2270     components.)
2272     49. Some changes have been made to the callout feature (see 28 above):
2274     (i) A callout function now has three choices for what it returns:
2276     0 => success, carry on matching
2277     > 0 => failure at this point, but backtrack if possible
2278     < 0 => serious error, return this value from pcre_exec()
2280     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2281     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2282     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2283     use by callout functions. It will never be used by PCRE itself.
2285     (ii) The pcre_extra structure (see 45 above) has a void * field called
2286     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2287     pcre_callout_block structure has a field of the same name. The contents of
2288     the field passed in the pcre_extra structure are passed to the callout
2289     function in the corresponding field in the callout block. This makes it
2290     easier to use the same callout-containing regex from multiple threads. For
2291     testing, the pcretest program has a new data escape
2293     \C*n pass the number n (may be negative) as callout_data
2295     If the callout function in pcretest receives a non-zero value as
2296     callout_data, it returns that value.
2298     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2299     there were some redundant $(CFLAGS) in commands that are now specified as
2300     $(LINK), which already includes $(CFLAGS).
2302     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2303     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2304     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2305     one-byte characters throughout. Note that case-insensitive matching applies
2306     only to characters whose values are less than 256. PCRE doesn't support the
2307     notion of cases for higher-valued characters.
2309     (i) A character class whose characters are all within 0-255 is handled as
2310     a bit map, and the map is inverted for negative classes. Previously, a
2311     character > 255 always failed to match such a class; however it should
2312     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2314     (ii) A negated character class with a single character < 255 is coded as
2315     "not this character" (OP_NOT). This wasn't working properly when the test
2316     character was multibyte, either singly or repeated.
2318     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2319     mode, for example: \x{100}{2,3}.
2321     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2322     singly or repeated) now correctly test multibyte characters. However,
2323     PCRE doesn't recognize any characters with values greater than 255 as
2324     digits, spaces, or word characters. Such characters always match \D, \S,
2325     and \W, and never match \d, \s, or \w.
2327     (v) Classes may now contain characters and character ranges with values
2328     greater than 255. For example: [ab\x{100}-\x{400}].
2330     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2331     PCRE in UTF-8 mode.
2333     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2334     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2335     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2336     value.)
2338     53. The single man page has become too large. I have therefore split it up into
2339     a number of separate man pages. These also give rise to individual HTML pages;
2340     these are now put in a separate directory, and there is an index.html page that
2341     lists them all. Some hyperlinking between the pages has been installed.
2343     54. Added convenience functions for handling named capturing parentheses.
2345     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2346     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2347     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2348     are faulted.
2350     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2351     calling configure. These values are used when compiling the dftables.c program
2352     which is run to generate the source of the default character tables. They
2353     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2354     you will need to set these values.
2356     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2359     Version 3.9 02-Jan-02
2360 nigel 61 ---------------------
2362     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2364     2. If --disable-static was given, the building process failed when trying to
2365     build pcretest and pcregrep. (For some reason it was using libtool to compile
2366     them, which is not right, as they aren't part of the library.)
2369 nigel 59 Version 3.8 18-Dec-01
2370     ---------------------
2372     1. The experimental UTF-8 code was completely screwed up. It was packing the
2373     bytes in the wrong order. How dumb can you get?
2376 nigel 57 Version 3.7 29-Oct-01
2377     ---------------------
2379     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2380     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2381     this didn't happen under Solaris 8, where I normally test things.
2383 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2384     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2385     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2386     this fix an hour or so after the initial 3.7 release.)
2387 nigel 57
2388 nigel 59
2389 nigel 55 Version 3.6 23-Oct-01
2390     ---------------------
2392     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2393     offsets passed as NULL with zero offset count.
2395     2. The config.guess and config.sub files had not been updated when I moved to
2396     the latest autoconf.
2399 nigel 53 Version 3.5 15-Aug-01
2400     ---------------------
2401 nigel 5
2402 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2403     had been forgotten.
2405     2. By using declared but undefined structures, we can avoid using "void"
2406     definitions in pcre.h while keeping the internal definitions of the structures
2407     private.
2409     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2410     user point of view, this means that both static and shared libraries are built
2411     by default, but this can be individually controlled. More of the work of
2412     handling this static/shared cases is now inside libtool instead of PCRE's make
2413     file.
2415     4. The pcretest utility is now installed along with pcregrep because it is
2416     useful for users (to test regexs) and by doing this, it automatically gets
2417     relinked by libtool. The documentation has been turned into a man page, so
2418     there are now .1, .txt, and .html versions in /doc.
2420     5. Upgrades to pcregrep:
2421     (i) Added long-form option names like gnu grep.
2422     (ii) Added --help to list all options with an explanatory phrase.
2423     (iii) Added -r, --recursive to recurse into sub-directories.
2424     (iv) Added -f, --file to read patterns from a file.
2426     6. pcre_exec() was referring to its "code" argument before testing that
2427     argument for NULL (and giving an error if it was NULL).
2429     7. Upgraded Makefile.in to allow for compiling in a different directory from
2430     the source directory.
2432     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2433     options bits, the pointer it was passed was to an int instead of to an unsigned
2434     long int. This mattered only on 64-bit systems.
2436     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2437     generated) instead of pcre.in, which it its source. Also made the same change
2438     in several of the .c files.
2440     10. A new release of gcc defines printf() as a macro, which broke pcretest
2441     because it had an ifdef in the middle of a string argument for printf(). Fixed
2442     by using separate calls to printf().
2444     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2445     script, to force use of CR or LF instead of \n in the source. On non-Unix
2446     systems, the value can be set in config.h.
2448     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2449     absolute limit. Changed the text of the error message to make this clear, and
2450     likewise updated the man page.
2452     13. The limit of 99 on the number of capturing subpatterns has been removed.
2453     The new limit is 65535, which I hope will not be a "real" limit.
2456 nigel 51 Version 3.4 22-Aug-00
2457     ---------------------
2459     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2461     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2464 nigel 49 Version 3.3 01-Aug-00
2465     ---------------------
2467     1. If an octal character was given, but the value was greater than \377, it
2468     was not getting masked to the least significant bits, as documented. This could
2469     lead to crashes in some systems.
2471     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2472     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2474     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2475     These just pass their arguments on to (pcre_free)(), but they are provided
2476     because some uses of PCRE bind it to non-C systems that can call its functions,
2477     but cannot call free() or pcre_free() directly.
2479     4. Add "make test" as a synonym for "make check". Corrected some comments in
2480     the Makefile.
2482     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2483     Makefile.
2485     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2486     command called pgrep for grepping around the active processes.
2488     7. Added the beginnings of support for UTF-8 character strings.
2490     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2491     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2492     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2493     out for the ar command.)
2496 nigel 47 Version 3.2 12-May-00
2497     ---------------------
2499     This is purely a bug fixing release.
2501     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2502     of ZA. This was just one example of several cases that could provoke this bug,
2503     which was introduced by change 9 of version 2.00. The code for breaking
2504     infinite loops after an iteration that matches an empty string was't working
2505     correctly.
2507     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2508     when matched against abbab (for example). After matching an empty string, it
2509     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2510     caused it to match further down the string than it should.
2512     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2513     was there because it doesn't seem to be needed, and it causes trouble on some
2514     systems, as it is not a Standard C header. It has been removed.
2516     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2517     were reported on the Macintosh. The changes were from
2519     while ((c = *(++ptr)) != 0 && c != '\n');
2520     to
2521     while ((c = *(++ptr)) != 0 && c != '\n') ;
2523     Totally extraordinary, but if that's what it takes...
2525     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2526     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2527     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2528     assumes the way PCRE uses memmove() (always moving upwards).
2530     6. PCRE is being used in one environment where strchr() is not available. There
2531     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2532     faster code anyway.
2535 nigel 45 Version 3.1 09-Feb-00
2536     ---------------------
2538     The only change in this release is the fixing of some bugs in Makefile.in for
2539     the "install" target:
2541     (1) It was failing to install pcreposix.h.
2543     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2546 nigel 43 Version 3.0 01-Feb-00
2547     ---------------------
2548 nigel 41
2549     1. Add support for the /+ modifier to perltest (to output $` like it does in
2550     pcretest).
2552     2. Add support for the /g modifier to perltest.
2554     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2555     matches null strings.
2557     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2558     pattern. Perl treats empty patterns specially - it reuses the most recent
2559     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2560     effect.
2562     5. The POSIX interface was broken in that it was just handing over the POSIX
2563     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2564     required a bigger vector, with some working space on the end. This means that
2565     the POSIX wrapper now has to get and free some memory, and copy the results.
2567 nigel 43 6. Added some simple autoconf support, placing the test data and the
2568     documentation in separate directories, re-organizing some of the
2569     information files, and making it build pcre-config (a GNU standard). Also added
2570     libtool support for building PCRE as a shared library, which is now the
2571     default.
2572 nigel 41
2573 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2574     09 are not valid octal constants. Single digits will be used for minor values
2575     less than 10.
2577     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2578     existing programs that set these in the POSIX interface can use PCRE without
2579     modification.
2581     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2582     return all that pcre_info() returns, plus additional data. The pcre_info()
2583     function is retained for compatibility, but is considered to be obsolete.
2585     10. Added experimental recursion feature (?R) to handle one common case that
2586     Perl 5.6 will be able to do with (?p{...}).
2588     11. Added support for POSIX character classes like [:alpha:], which Perl is
2589     adopting.
2592 nigel 39 Version 2.08 31-Aug-99
2593     ----------------------
2595     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2596     trying to match at the startoffset position, but instead was moving forward to
2597     the next newline as if a previous match had failed.
2599     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2600     and could get into a loop if a null string was matched other than at the start
2601     of the subject.
2603     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2604     be distinguished at compile time, and for completeness also added PCRE_DATE.
2606     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2607     in GnuWin32 environments.
2610 nigel 37 Version 2.07 29-Jul-99
2611     ----------------------
2613     1. The documentation is now supplied in plain text form and HTML as well as in
2614     the form of man page sources.
2616     2. C++ compilers don't like assigning (void *) values to other pointer types.
2617     In particular this affects malloc(). Although there is no problem in Standard
2618     C, I've put in casts to keep C++ compilers happy.
2620     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2621     should be (const char *).
2623     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2624     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2625     However, I haven't made this a standard facility. The documentation doesn't
2626     mention it, and the Makefile doesn't support it.
2628     5. The Makefile now contains an "install" target, with editable destinations at
2629     the top of the file. The pcretest program is not installed.
2631     6. pgrep -V now gives the PCRE version number and date.
2633     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2634     causing the entire string to be ignored, instead of just the last character.
2636     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2637     non-matching string, it can take a very, very long time, even for strings of
2638     quite modest length, because of the nested recursion. PCRE now does better in
2639     some of these cases. It does this by remembering the last required literal
2640     character in the pattern, and pre-searching the subject to ensure it is present
2641     before running the real match. In other words, it applies a heuristic to detect
2642     some types of certain failure quickly, and in the above example, if presented
2643     with a string that has no trailing " it gives "no match" very quickly.
2645     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2646     other alternatives are tried instead.
2649 nigel 35 Version 2.06 09-Jun-99
2650     ----------------------
2652     1. Change pcretest's output for amount of store used to show just the code
2653     space, because the remainder (the data block) varies in size between 32-bit and
2654     64-bit systems.
2656     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2657     start matching at. This allows lookbehinds to work when searching for multiple
2658     occurrences in a string.
2660     3. Added additional options to pcretest for testing multiple occurrences:
2662     /+ outputs the rest of the string that follows a match
2663     /g loops for multiple occurrences, using the new startoffset argument
2664     /G loops for multiple occurrences by passing an incremented pointer
2666     4. PCRE wasn't doing the "first character" optimization for patterns starting
2667     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2668     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2669     the letter 'x'. On long subject strings, this gives a significant speed-up.
2672 nigel 33 Version 2.05 21-Apr-99
2673     ----------------------
2675     1. Changed the type of magic_number from int to long int so that it works
2676     properly on 16-bit systems.
2678     2. Fixed a bug which caused patterns starting with .* not to work correctly
2679     when the subject string contained newline characters. PCRE was assuming
2680     anchoring for such patterns in all cases, which is not correct because .* will
2681     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2682     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2683     must be retried after every newline in the subject.
2686 nigel 31 Version 2.04 18-Feb-99
2687     ----------------------
2689     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2690     computation of the store needed to hold the pattern was incorrect (too large).
2691     If such patterns were nested a few deep, this could multiply and become a real
2692     problem.
2694     2. Added /M option to pcretest to show the memory requirement of a specific
2695     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2697     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2698     compiled in such a way that the backtracking after subsequent failure was
2699     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2700     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2703 nigel 29 Version 2.03 02-Feb-99
2704     ----------------------
2706     1. Fixed typo and small mistake in man page.
2708 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2709     LICENCE file containing the conditions.
2710 nigel 29
2711     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2712     Perl, that is the internal \ allows the delimiter to be included in the
2713     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2714     the final delimiter, add \ to the end of the pattern (to test the error).
2716     4. Added the convenience functions for extracting substrings after a successful
2717     match. Updated pcretest to make it able to test these functions.
2720 nigel 27 Version 2.02 14-Jan-99
2721     ----------------------
2723     1. Initialized the working variables associated with each extraction so that
2724     their saving and restoring doesn't refer to uninitialized store.
2726     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2727     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2728     fix the problem.
2730     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2731     calls, and wasn't printing the correct value for compiling calls. Increased the
2732     default value of LOOPREPEAT, and the number of significant figures in the
2733     times.
2735     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2737     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2738     a building problem on Windows NT with a FAT file system.
2741 nigel 25 Version 2.01 21-Oct-98
2742     ----------------------
2744     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2745     to character tables built by pcre_maketables() in the current locale. If NULL
2746     is passed, the default tables are used.
2749 nigel 23 Version 2.00 24-Sep-98
2750 nigel 21 ----------------------
2752 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2753     it any more.
2755     2. Allow quantification of (?>) groups, and make it work correctly.
2757     3. The first character computation wasn't working for (?>) groups.
2759     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2760     end of the subject) and add 5.005's \z, which really does match only at the
2761     very end of the subject.
2763     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2765     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2766     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2767     localized options. All options to pcre_study() were also removed.
2769     7. Add other new features from 5.005:
2771     $(?<= positive lookbehind
2772     $(?<! negative lookbehind
2773     (?imsx-imsx) added the unsetting capability
2774     such a setting is global if at outer level; local otherwise
2775     (?imsx-imsx:) non-capturing groups with option setting
2776     (?(cond)re|re) conditional pattern matching
2778     A backreference to itself in a repeated group matches the previous
2779     captured string.
2781     8. General tidying up of studying (both automatic and via "study")
2782     consequential on the addition of new assertions.
2784     9. As in 5.005, unlimited repeated groups that could match an empty substring
2785     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2786     runtime if any iteration does actually match an empty substring.
2788     10. Include the RunTest script in the distribution.
2790     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2791     discrepancies, some of which were old and were also with respect to 5.004. They
2792     have now been fixed.
2795     Version 1.09 28-Apr-98
2796     ----------------------
2798 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2799     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2800     program crashes, or just wrong answers. This did not apply to negated classes
2801     containing more than one character, or to minima other than one.
2804 nigel 19 Version 1.08 27-Mar-98
2805     ----------------------
2807     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2809     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2810     latter must appear before anything that relies on it in the pattern.
2813 nigel 17 Version 1.07 16-Feb-98
2814     ----------------------
2816     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2817     repeat of a potentially empty string).
2820 nigel 15 Version 1.06 23-Jan-98
2821     ----------------------
2823     1. Added Markus Oberhumer's little patches for C++.
2825     2. Literal strings longer than 255 characters were broken.
2828 nigel 13 Version 1.05 23-Dec-97
2829     ----------------------
2831     1. Negated character classes containing more than one character were failing if
2832     PCRE_CASELESS was set at run time.
2835 nigel 11 Version 1.04 19-Dec-97
2836     ----------------------
2838     1. Corrected the man page, where some "const" qualifiers had been omitted.
2840     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2841     input syntax.
2843     3. Fixed memory leak which occurred when a regex with back references was
2844     matched with an offsets vector that wasn't big enough. The temporary memory
2845     that is used in this case wasn't being freed if the match failed.
2847     4. Tidied pcretest to ensure it frees memory that it gets.
2849     5. Temporary memory was being obtained in the case where the passed offsets
2850     vector was exactly big enough.
2852     6. Corrected definition of offsetof() from change 5 below.
2854     7. I had screwed up change 6 below and broken the rules for the use of
2855     setjmp(). Now fixed.
2858 nigel 9 Version 1.03 18-Dec-97
2859     ----------------------
2861     1. A erroneous regex with a missing opening parenthesis was correctly
2862     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2863     on some systems.
2865     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2866     it was reported that one broken compiler failed on the former because "code" is
2867     also an independent variable.
2869     3. The erroneous regex a[]b caused an array overrun reference.
2871     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2872     fail on data ending with that character. (It was going on too far, and checking
2873     the next character, typically a binary zero.) This was specific to the
2874     optimized code for single-character negative classes.
2876     5. Added a contributed patch from the TIN world which does the following:
2878     + Add an undef for memmove, in case the the system defines a macro for it.
2880     + Add a definition of offsetof(), in case there isn't one. (I don't know
2881     the reason behind this - offsetof() is part of the ANSI standard - but
2882     it does no harm).
2884     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2885     most of the places where whitespace preceded '#'. I have given up and
2886     allowed the remaining 2 cases to be at the margin.
2888     + Rename some variables in pcre to eliminate shadowing. This seems very
2889     pedantic, but does no harm, of course.
2891     6. Moved the call to setjmp() into its own function, to get rid of warnings
2892     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2894     7. Constructs such as \d{8,} were compiling into the equivalent of
2895 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2896 nigel 9 outcome, but in this particular case used more store than had been allocated,
2897     which caused the bug to be discovered because it threw up an internal error.
2899     8. The debugging code in both pcre and pcretest for outputting the compiled
2900     form of a regex was going wrong in the case of back references followed by
2901     curly-bracketed repeats.
2904 nigel 7 Version 1.02 12-Dec-97
2905     ----------------------
2907     1. Typos in pcre.3 and comments in the source fixed.
2909     2. Applied a contributed patch to get rid of places where it used to remove
2910     'const' from variables, and fixed some signed/unsigned and uninitialized
2911     variable warnings.
2913     3. Added the "runtest" target to Makefile.
2915     4. Set default compiler flag to -O2 rather than just -O.
2918 nigel 5 Version 1.01 19-Nov-97
2919     ----------------------
2921     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2922     like /([ab]*)*/, that is, for classes with more than one character in them.
2924     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2925     as /((?>a*))*/ (a PCRE_EXTRA facility).
2928     Version 1.00 18-Nov-97
2929     ----------------------
2931     1. Added compile-time macros to support systems such as SunOS4 which don't have
2932     memmove() or strerror() but have other things that can be used instead.
2934     2. Arranged that "make clean" removes the executables.
2937 nigel 3 Version 0.99 27-Oct-97
2938     ----------------------
2940     1. Fixed bug in code for optimizing classes with only one character. It was
2941     initializing a 32-byte map regardless, which could cause it to run off the end
2942     of the memory it had got.
2944     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2947     Version 0.98 22-Oct-97
2948     ----------------------
2950     1. Fixed bug in code for handling temporary memory usage when there are more
2951     back references than supplied space in the ovector. This could cause segfaults.
2954     Version 0.97 21-Oct-97
2955     ----------------------
2957     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2959     2. Optimized negated single characters not to use a bit map.
2961     3. Brought error texts together as macro definitions; clarified some of them;
2962     fixed one that was wrong - it said "range out of order" when it meant "invalid
2963     escape sequence".
2965     4. Changed some char * arguments to const char *.
2967     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2969     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2970     pcretest.
2973     Version 0.96 16-Oct-97
2974     ----------------------
2976     1. Added a simple "pgrep" utility to the distribution.
2978     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2979     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2980     where "ddd" means "one or more decimal digits".
2982     3. Fixed serious bug. If a pattern had a back reference, but the call to
2983     pcre_exec() didn't supply a large enough ovector to record the related
2984     identifying subpattern, the match always failed. PCRE now remembers the number
2985     of the largest back reference, and gets some temporary memory in which to save
2986     the offsets during matching if necessary, in order to ensure that
2987     backreferences always work.
2989     4. Increased the compatibility with Perl in a number of ways:
2991     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2992     to request this handling. The option can be set at compile or exec time.
2994     (b) $ matches before a terminating newline by default; an option
2995     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2996     mode). The option can be set at compile or exec time.
2998     (c) The handling of \ followed by a digit other than 0 is now supposed to be
2999     the same as Perl's. If the decimal number it represents is less than 10
3000     or there aren't that many previous left capturing parentheses, an octal
3001     escape is read. Inside a character class, it's always an octal escape,
3002     even if it is a single digit.
3004     (d) An escaped but undefined alphabetic character is taken as a literal,
3005     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3006     escapes.
3008     (e) {0} is now permitted. (The previous item is removed from the compiled
3009     pattern).
3011     5. Changed all the names of code files so that the basic parts are no longer
3012     than 10 characters, and abolished the teeny "globals.c" file.
3014     6. Changed the handling of character classes; they are now done with a 32-byte
3015     bit map always.
3017     7. Added the -d and /D options to pcretest to make it possible to look at the
3018     internals of compilation without having to recompile pcre.
3021     Version 0.95 23-Sep-97
3022     ----------------------
3024     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3025     \x20 at the start of a run of normal characters. These were being treated as
3026     real characters, instead of the source characters being re-checked.
3029     Version 0.94 18-Sep-97
3030     ----------------------
3032     1. The functions are now thread-safe, with the caveat that the global variables
3033     containing pointers to malloc() and free() or alternative functions are the
3034     same for all threads.
3036     2. Get pcre_study() to generate a bitmap of initial characters for non-
3037     anchored patterns when this is possible, and use it if passed to pcre_exec().
3040     Version 0.93 15-Sep-97
3041     ----------------------
3043     1. /(b)|(:+)/ was computing an incorrect first character.
3045     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3046     but not actually doing anything yet.
3048     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3049     as Perl does (e.g. [-az] or [az-]).
3051     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3052     all possible positions.
3054     5. Split up into different modules to avoid including unneeded functions in a
3055     compiled binary. However, compile and exec are still in one module. The "study"
3056     function is split off.
3058     6. The character tables are now in a separate module whose source is generated
3059     by an auxiliary program - but can then be edited by hand if required. There are
3060     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3061     toupper() in the code.
3063     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3064     make them global. Abolish the function for setting them, as the caller can now
3065     set them directly.
3068     Version 0.92 11-Sep-97
3069     ----------------------
3071     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3072     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3074     2. Caseless matching was not working in character classes if the characters in
3075     the pattern were in upper case.
3077     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3079     4. Make PCRE_ANCHORED public and accept as a compile option.
3081     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3082     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3083     pass them.
3085     6. Give an error if bad option bits passed at compile or run time.
3087     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3088     pcretest to cause it to pass that flag.
3090     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3091     options, and the first character, if set.
3093     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3096     Version 0.91 10-Sep-97
3097     ----------------------
3099     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3100     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3102     2. PCRE was looping on encountering an indefinitely repeated back reference to
3103     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3104     Perl does - treats the match as successful.
3106     ****


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

ViewVC Help
Powered by ViewVC 1.1.12