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Revision 319 - (hide annotations) (download)
Mon Jan 28 15:27:45 2008 UTC (7 years, 2 months ago) by ph10
File size: 150740 byte(s)
File tidy-up for 7.6 release.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 319 Version 7.6 28-Jan-08
5 ph10 300 ---------------------
7 ph10 302 1. A character class containing a very large number of characters with
8     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
9     overflow.
10 ph10 309
11     2. Patch to cut out the "long long" test in pcrecpp_unittest when
12     HAVE_LONG_LONG is not defined.
14 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
15 ph10 304 bring them up to date and include new features. This patch includes:
16 ph10 309
17 ph10 304 - Fixed PH's badly added libz and libbz2 support.
18     - Fixed a problem with static linking.
19 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
20 ph10 304 - Fixed dftables problem and added an option.
21     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
23     - Added readline support for pcretest.
24 ph10 309 - Added an listing of the option settings after cmake has run.
26 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
27     "pcre.dll" under mingw when using Configure/Make. I added stuff to
28     Makefile.am that cause it to include this special target, without
29     affecting anything else. Note that the same mingw target plus all
30     the other distribution libraries and programs are now supported
31     when configuring with CMake (see 6 below) instead of with
32     Configure/Make.
33 ph10 309
34 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
35     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
36 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
37     solves the problem, but it does no harm.
38 ph10 313
39 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
40 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
41 ph10 314 with CMake, and also correct the comment about stack recursion.
42 ph10 313
43 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
44 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
45     of a program that users should build themselves after PCRE is installed, so
46     building it automatically is not really right. What is more, it gave
47 ph10 312 trouble in some build environments.
48 ph10 300
49 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
50 ph10 308
51 ph10 319
52 ph10 298 Version 7.5 10-Jan-08
53 ph10 263 ---------------------
55     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
56     values in parens when parsing an RE using the C++ wrapper."
57 ph10 286
58 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
59     Characters greater than 255 were excluded from the class instead of being
60     included.
61 ph10 286
62     3. The same bug as (2) above applied to negated POSIX classes such as
63 ph10 265 [:^space:].
64 ph10 286
65 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
66     defined or documented. It seems to have been a typo for PCRE_STATIC, so
67 ph10 286 I have changed it.
69 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
70 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
71     first named subpattern whose name started with "a" (in other words, the
72 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
73     expected" is now given for (?&) (a zero-length name), and this patch also
74     makes it give the same error for \k'' (previously it complained that that
75     was a reference to a non-existent subpattern).
76 ph10 286
77 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
78 ph10 286 this is right because (?- can be followed by option settings as well as by
79 ph10 269 digits. I have, however, made the messages clearer.
80 ph10 286
81 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
82     than the number used in the conditional) now cause a compile-time error.
83     This is actually not compatible with Perl, which accepts such patterns, but
84     treats the conditional as always being FALSE (as PCRE used to), but it
85     seems to me that giving a diagnostic is better.
86 ph10 286
87 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
88 ph10 275 and messages.
89 ph10 286
90     9. Fix two occurrences of "backslash" in comments that should have been
91     "backspace".
93     10. Remove two redundant lines of code that can never be obeyed (their function
94     was moved elsewhere).
96     11. The program that makes PCRE's Unicode character property table had a bug
97     which caused it to generate incorrect table entries for sequences of
98 ph10 277 characters that have the same character type, but are in different scripts.
99 ph10 286 It amalgamated them into a single range, with the script of the first of
100 ph10 277 them. In other words, some characters were in the wrong script. There were
101     thirteen such cases, affecting characters in the following ranges:
102 ph10 286
103 ph10 277 U+002b0 - U+002c1
104     U+0060c - U+0060d
105 ph10 286 U+0061e - U+00612
106 ph10 277 U+0064b - U+0065e
107     U+0074d - U+0076d
108     U+01800 - U+01805
109     U+01d00 - U+01d77
110     U+01d9b - U+01dbf
111     U+0200b - U+0200f
112     U+030fc - U+030fe
113     U+03260 - U+0327f
114     U+0fb46 - U+0fbb1
115     U+10450 - U+1049d
116 ph10 286
117 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
118     compatible with GNU grep in that, if there was more than one match in a
119     line, it showed only the first of them. It now behaves in the same way as
120     GNU grep.
121 ph10 286
122     13. If the -o and -v options were combined for pcregrep, it printed a blank
123     line for every non-matching line. GNU grep prints nothing, and pcregrep now
124     does the same. The return code can be used to tell if there were any
125     non-matching lines.
127 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
129     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
130 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
131 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
132     and both kinds of lookbehind were skipped).
134 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
135 ph10 284 inclusion of <windows.h> to before rather than after the definition of
136     INVALID_FILE_ATTRIBUTES (patch from David Byron).
137 ph10 263
138 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
139 ph10 286 character property caused pcre_compile() to compile bad code, which led at
140     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
141     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
142     caused the error; without that there was no problem.
143 ph10 263
144 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
145 ph10 286
146 ph10 289 19. Added --enable-pcretest-libreadline.
147 ph10 286
148 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
149 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
150 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
151     later patch that removed the other one (the right fix) and added unit tests
152     that check the return values (which was not done before).
153 ph10 292
154 ph10 291 21. Several CMake things:
155 ph10 287
156 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
157 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
158 ph10 288
159 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
160     linked with the newly-built libraries, not previously installed ones.
161 ph10 291
163 ph10 298
164     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
165     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
166     UTF-8 newline character). The key issue is that the pattern starts .*;
167     this means that the match must be either at the beginning, or after a
168     newline. The bug was in the code for advancing after a failed match and
169     checking that the new position followed a newline. It was not taking
170 ph10 294 account of UTF-8 characters correctly.
171 ph10 298
172     23. PCRE was behaving differently from Perl in the way it recognized POSIX
173     character classes. PCRE was not treating the sequence [:...:] as a
174     character class unless the ... were all letters. Perl, however, seems to
175     allow any characters between [: and :], though of course it rejects as
176     unknown any "names" that contain non-letters, because all the known class
177     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
178     for example, whereas PCRE did not - it did not recognize a POSIX character
179     class. This seemed a bit dangerous, so the code has been changed to be
180     closer to Perl. The behaviour is not identical to Perl, because PCRE will
181     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
182     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
183     Perl does, and where it didn't before.
185 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
186     Windows environments %n is disabled by default.
187 ph10 292
189 ph10 260 Version 7.4 21-Sep-07
190 ph10 230 ---------------------
192     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
193 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
194     LF". That isn't really right - the whole point of the change was to try to
195     help when there was an actual mention of one of the two characters. So now
196     the change happens only if \r or \n (or a literal CR or LF) character is
197 ph10 230 encountered.
198 ph10 231
199     2. The 32-bit options word was also used for 6 internal flags, but the numbers
200     of both had grown to the point where there were only 3 bits left.
201     Fortunately, there was spare space in the data structure, and so I have
202     moved the internal flags into a new 16-bit field to free up more option
203 ph10 230 bits.
204 ph10 231
205     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
206     but did not set the internal JCHANGED flag - either of these is enough to
207     control the way the "get" function works - but the PCRE_INFO_JCHANGED
208     facility is supposed to tell if (?J) was ever used, so now (?J) at the
209 ph10 230 start sets both bits.
211 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
212     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
213 ph10 230
214 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
216     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
217 ph10 233 compatibility, even though it is no longer used.
218 ph10 243
219     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
220 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
221 ph10 259 windows.h file is present (where different names are used). [This was
222 ph10 257 reversed later after testing - see 16 below.]
223 ph10 243
224     8. Changed all #include <config.h> to #include "config.h". There were also
225 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
226 ph10 243
227 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
228 ph10 243 sequence off the lines that it output.
230     10. It was pointed out to me that arrays of string pointers cause lots of
231     relocations when a shared library is dynamically loaded. A technique of
232     using a single long string with a table of offsets can drastically reduce
233     these. I have refactored PCRE in four places to do this. The result is
234 ph10 240 dramatic:
235 ph10 243
236 ph10 240 Originally: 290
237     After changing UCP table: 187
238 ph10 243 After changing error message table: 43
239 ph10 240 After changing table of "verbs" 36
240     After changing table of Posix names 22
241 ph10 243
242 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
243 ph10 247
244 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
245 ph10 247 unicode-properties was also set.
247 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
248 ph10 231
249 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
250     checked only for CRLF.
251 ph10 233
252 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
254 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
255 ph10 253
256 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
257 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
258     entirely. This removes changes made in 7 above.
259 ph10 256
260 ph10 261 17. The CMake files have been updated, and there is now more information about
261     building with CMake in the NON-UNIX-USE document.
262 ph10 257
263 ph10 261
264 ph10 228 Version 7.3 28-Aug-07
265 ph10 157 ---------------------
267 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
268     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
269     brackets there is not right, since it causes compilers to look for an
270     installed pcre.h, not the version that is in the source that is being
271     compiled (which of course may be different). I have changed it back to:
272 ph10 197
273 ph10 189 #include "pcre.h"
274 ph10 197
275     I have a vague recollection that the change was concerned with compiling in
276     different directories, but in the new build system, that is taken care of
277     by the VPATH setting the Makefile.
279 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
280     when the subject happened to end in the byte 0x85 (e.g. if the last
281     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
282     characters but of course it shouldn't be taken as a newline when it is part
283     of another character. The bug was that, for an unlimited repeat of . in
284     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
285     characters when looking for a newline.
286 ph10 197
287     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
289     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
290     in debug output.
292 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
293     long printing in the pcrecpp unittest when running under MinGW.
294 ph10 189
295 ph10 197 6. ESC_K was left out of the EBCDIC table.
296 ph10 189
297 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
298     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
299     limit also applies to "virtual nesting" when a pattern is recursive, and in
300     this case 1000 isn't so big. I have been able to remove this limit at the
301     expense of backing off one optimization in certain circumstances. Normally,
302     when pcre_exec() would call its internal match() function recursively and
303     immediately return the result unconditionally, it uses a "tail recursion"
304     feature to save stack. However, when a subpattern that can match an empty
305     string has an unlimited repetition quantifier, it no longer makes this
306     optimization. That gives it a stack frame in which to save the data for
307     checking that an empty string has been matched. Previously this was taken
308     from the 1000-entry workspace that had been reserved. So now there is no
309     explicit limit, but more stack is used.
310 ph10 189
311 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
312     syntax that is required for Windows, and which was going wrong for the
313     pcreposix and pcrecpp parts of the library. These were overlooked when this
314     problem was solved for the main library.
315 ph10 197
316 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
317     the size of patterns that contain repeated groups with explicit upper
318     limits. As the maximum quantifier is 65535, the maximum group length was
319     set at 30,000 so that the product of these two numbers did not overflow a
320     32-bit integer. However, it turns out that people want to use groups that
321     are longer than 30,000 bytes (though not repeat them that many times).
322     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
323     made it possible to implement the integer overflow checks in a much more
324     dynamic way, which I have now done. The artificial limitation on group
325     length has been removed - we now have only the limit on the total length of
326     the compiled pattern, which depends on the LINK_SIZE setting.
327 ph10 208
328     10. Fixed a bug in the documentation for get/copy named substring when
329     duplicate names are permitted. If none of the named substrings are set, the
330     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
331     empty string.
333     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
334     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
335     because the ] is interpreted as the first data character and the
336     terminating ] is not found. PCRE has been made compatible with Perl in this
337     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
338     cause memory overwriting.
340 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
341     string has been matched (to stop an infinite loop). It was not recognizing
342 ph10 208 a conditional subpattern that could match an empty string if that
343 ph10 206 subpattern was within another subpattern. For example, it looped when
344 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
345 ph10 206 condition was not nested. This bug has been fixed.
346 ph10 208
347 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
348     past the start of the subject in the presence of bytes with the top bit
349     set, for example "\x8aBCD".
350 ph10 211
351 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
352     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
353 ph10 200
354 ph10 211 14. Optimized (?!) to (*FAIL).
355 ph10 202
356 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
357     This restricts code points to be within the range 0 to 0x10FFFF, excluding
358     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
359     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
360     does: it's just the validity check that is more restrictive.
361 ph10 220
362     16. Inserted checks for integer overflows during escape sequence (backslash)
363     processing, and also fixed erroneous offset values for syntax errors during
364     backslash processing.
366 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
367 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
369 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
370     caused an overrun.
371 ph10 220
372     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
373     something other than just ASCII characters) inside a group that had an
374     unlimited repeat caused a loop at compile time (while checking to see
375     whether the group could match an empty string).
377 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
378     [\P{Any}] did so. (Error in the code for printing property names.)
379 ph10 210
380 ph10 220 21. An orphan \E inside a character class could cause a crash.
382     22. A repeated capturing bracket such as (A)? could cause a wild memory
383 ph10 218 reference during compilation.
384 ph10 220
385     23. There are several functions in pcre_compile() that scan along a compiled
386     expression for various reasons (e.g. to see if it's fixed length for look
387 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
388 ph10 220 present in the pattern. These operators have additional parameters compared
389     with \d, etc, and these were not being taken into account when moving along
390 ph10 218 the compiled data. Specifically:
391 ph10 220
392     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
393     length.
395     (b) An item such as \pL+ within a repeated group could cause crashes or
396 ph10 218 loops.
397 ph10 220
398 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
399 ph10 220 "reference to non-existent subpattern" error.
401 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
403 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
404 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
405 ph10 211
406 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
407 ph10 218
408 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
409 ph10 223 character were causing crashes (broken optimization).
410 ph10 227
411 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
412 ph10 227 \p or \P) caused a compile-time loop.
414 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
415     break. For example, the unstudied pattern [\r\n]A does not match the string
416     "\r\nA" because change 7.0/46 below moves the current point on by two
417     characters after failing to match at the start. However, the pattern \nA
418 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
419     the same is true. There doesn't seem any very clean way out of this, but
420     what I have chosen to do makes the common cases work: PCRE now takes note
421     of whether there can be an explicit match for \r or \n anywhere in the
422     pattern, and if so, 7.0/46 no longer applies. As part of this change,
423     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
424     pattern has explicit CR or LF references.
425 ph10 222
426 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
427 ph10 223
428 ph10 227
429 ph10 189 Version 7.2 19-Jun-07
430     ---------------------
432 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
433     which is apparently normally available under Windows.
434 ph10 159
435     2. Re-jig the pcregrep tests with different newline settings in an attempt
436     to make them independent of the local environment's newline setting.
437 ph10 157
438 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
439 ph10 165
440 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
441     was not 2, because the output contained actual offsets. The recent new
442 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
443     usable with all link sizes.
445 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
446     stack recursion. This gives a massive performance boost under BSD, but just
447 ph10 165 a small improvement under Linux. However, it saves one field in the frame
448 ph10 164 in all cases.
449 ph10 172
450 ph10 166 6. Added more features from the forthcoming Perl 5.10:
451 ph10 172
452 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
453     recursion call. It refers to the nth most recently opened parentheses.
454 ph10 172
455 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
456 ph10 172 to be opened parentheses.
458     (c) Conditions that refer to capturing parentheses can be specified
459 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
460 ph10 172
461 ph10 168 (d) \K resets the start of the current match so that everything before
462 ph10 172 is not part of it.
464 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
465 ph10 172
466 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
467 ph10 172 reference syntax.
468 ph10 182
469 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
470 ph10 182 alternative starts with the same number.
471 ph10 172
472 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
474 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
477     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
478     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
479 ph10 170 for detecting groups that can match an empty string.
480 ph10 159
481 ph10 172 9. A pattern with a very large number of alternatives (more than several
482     hundred) was running out of internal workspace during the pre-compile
483     phase, where pcre_compile() figures out how much memory will be needed. A
484     bit of new cunning has reduced the workspace needed for groups with
485     alternatives. The 1000-alternative test pattern now uses 12 bytes of
486     workspace instead of running out of the 4096 that are available.
487 ph10 182
488 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
489 ph10 172
490 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
491     The report of the bug said:
492 ph10 182
493 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
494     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
495 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
496 ph10 185
497 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
498 ph10 185 it matched the wrong number of bytes.
499 ph10 172
500 ph10 179
501 ph10 155 Version 7.1 24-Apr-07
502 ph10 98 ---------------------
504 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
505 ph10 122 that is more "standard", making use of automake and other Autotools. There
506 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
507     on this.
508 ph10 111
509     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
510     for recursive directory scanning broke on some systems because the files
511     are not scanned in any specific order and on different systems the order
512     was different. A call to "sort" has been inserted into RunGrepTest for the
513     approprate test as a short-term fix. In the longer term there may be an
514 ph10 100 alternative.
515 ph10 111
516 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
517 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
518     people do their own conversions for various reasons). The problems
519     concerned the use of low-level troff macros .br and .in. I have therefore
520     removed all such uses from the man pages (some were redundant, some could
521 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
522     HTML has been updated to handle .nf/.fi and to complain if it encounters
523     .br or .in.
524 ph10 111
525 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
526 ph10 123 arranged for config.h to be included in the distribution, with the name
527 ph10 111 config.h.generic, for the benefit of those who have to compile without
528     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
530     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
531     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
532 ph10 127 makevp.bat for the current PCRE, using the additional files
533 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
534 ph10 111
535     6. A Windows user reported a minor discrepancy with test 2, which turned out
536     to be caused by a trailing space on an input line that had got lost in his
537 ph10 102 copy. The trailing space was an accident, so I've just removed it.
538 ph10 111
539 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
540 ph10 111 that is needed.
542 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
543     as "const" (a) because they are and (b) because it helps the PHP
544     maintainers who have recently made a script to detect big data structures
545 ph10 111 in the php code that should be moved to the .rodata section. I remembered
546     to update Builducptable as well, so it won't revert if ucptable.h is ever
547 ph10 105 re-created.
548 ph10 111
549     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
550 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
551 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
552     support is not required. This saves 1.5-2K of code, which is important in
553 ph10 107 some applications.
554 ph10 111
555 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
556 ph10 111 so as not to refer to the tables, even though these functions will never be
557     called when UTF-8 support is disabled. Otherwise there are problems with a
558     shared library.
560 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
562     (a) It was defining its arguments as char * instead of void *.
564 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
565     a long time ago when I wrote it, but is no longer the case.
567 ph10 118 The emulated memove() is provided for those environments that have neither
568 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
569 ph10 118 is clearly not the case, as these two bugs were recently reported.
570 ph10 123
571 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
572 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
573     pages, and it removes trailing spaces from listed files. It also creates
574     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
575     case, it wraps all the #defines with #ifndefs. This script should be run
576 ph10 111 before "make dist".
577 ph10 123
578 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
579     with Unicode property support.
580 ph10 123
581     (a) For a maximizing quantifier, if the two different cases of the
582     character were of different lengths in their UTF-8 codings (there are
583     some cases like this - I found 11), and the matching function had to
584 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
585     were both the same length.
586 ph10 123
587     (b) When PCRE was configured to use the heap rather than the stack for
588     recursion during matching, it was not correctly preserving the data for
589     the other case of a UTF-8 character when checking ahead for a match
590     while processing a minimizing repeat. If the check also involved
591 ph10 115 matching a wide character, but failed, corruption could cause an
592     erroneous result when trying to check for a repeat of the original
593     character.
594 ph10 123
595 ph10 116 13. Some tidying changes to the testing mechanism:
596 ph10 98
597 ph10 116 (a) The RunTest script now detects the internal link size and whether there
598     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
599 ph10 123 values substituted by "configure". (The RunGrepTest script already did
600     this for UTF-8.) The configure.ac script no longer substitutes the
601     relevant variables.
603 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
604     with length and offset values. This means that the output is different
605     for different internal link sizes. Test 2 is skipped for link sizes
606     other than 2 because of this, bypassing the problem. Unfortunately,
607     there was also a test in test 3 (the locale tests) that used /B and
608 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
609     I have added a new /Z option to pcretest that replaces the length and
610     offset values with spaces. This is now used to make test 3 independent
611 ph10 122 of link size. (Test 2 will be tidied up later.)
612 ph10 123
613     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
614 ph10 122 segmentation fault instead of returning the appropriate error message.
615 ph10 134
616 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
617 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
618     This doesn't seem right; it now treats the CRLF combination as the line
619     ending, and so does not match in that case. It's only a pattern such as ^$
620     that would hit this one: something like ^ABC$ would have failed after \r
621     and then tried again after \r\n.
623 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
624 ph10 134 in an attempt to make files that differ only in their line terminators
625     compare equal. This works on Linux.
626 ph10 142
627 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
628     as it exited. This is now fixed, thanks to valgrind.
629 ph10 142
630 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
631 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
632     was because its rules for how to advance for /g after matching an empty
633 ph10 143 string at the end of a line did not allow for this case. They now check for
634     it specially.
635 ph10 150
636     20. pcretest is supposed to handle patterns and data of any length, by
637     extending its buffers when necessary. It was getting this wrong when the
638 ph10 147 buffer for a data line had to be extended.
639 ph10 150
640 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
641 ph10 150 CRLF as a newline sequence.
642 ph10 152
643 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
644 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
645     I have nevertheless tidied it up.
646 ph10 111
647 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
648 ph10 123
649 ph10 153 24. Added a man page for pcre-config.
650 ph10 152
651 ph10 153
652 nigel 93 Version 7.0 19-Dec-06
653     ---------------------
655     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
656     moving to gcc 4.1.1.
658     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
659     sys/time.h, which is documented as needed for this function. It doesn't
660     seem to matter on Linux, but it showed up on some releases of OS X.
662     3. It seems that there are systems where bytes whose values are greater than
663     127 match isprint() in the "C" locale. The "C" locale should be the
664     default when a C program starts up. In most systems, only ASCII printing
665     characters match isprint(). This difference caused the output from pcretest
666     to vary, making some of the tests fail. I have changed pcretest so that:
668     (a) When it is outputting text in the compiled version of a pattern, bytes
669     other than 32-126 are always shown as hex escapes.
671     (b) When it is outputting text that is a matched part of a subject string,
672     it does the same, unless a different locale has been set for the match
673     (using the /L modifier). In this case, it uses isprint() to decide.
675     4. Fixed a major bug that caused incorrect computation of the amount of memory
676     required for a compiled pattern when options that changed within the
677     pattern affected the logic of the preliminary scan that determines the
678     length. The relevant options are -x, and -i in UTF-8 mode. The result was
679     that the computed length was too small. The symptoms of this bug were
680     either the PCRE error "internal error: code overflow" from pcre_compile(),
681     or a glibc crash with a message such as "pcretest: free(): invalid next
682     size (fast)". Examples of patterns that provoked this bug (shown in
683     pcretest format) are:
685     /(?-x: )/x
686     /(?x)(?-x: \s*#\s*)/
687     /((?i)[\x{c0}])/8
688     /(?i:[\x{c0}])/8
690     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
691     is now done differently.
693     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
694     wrapper classes; (b) implement a new function in the C++ scanner that is
695     more efficient than the old way of doing things because it avoids levels of
696     recursion in the regex matching; (c) add a paragraph to the documentation
697     for the FullMatch() function.
699     6. The escape sequence \n was being treated as whatever was defined as
700     "newline". Not only was this contrary to the documentation, which states
701     that \n is character 10 (hex 0A), but it also went horribly wrong when
702     "newline" was defined as CRLF. This has been fixed.
704     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
705     was being set to -1 for the "end of line" case (supposedly a value that no
706     character can have). Though this value is never used (the check for end of
707     line is "zero bytes in current character"), it caused compiler complaints.
708     I've changed it to 0xffffffff.
710     8. In pcre_version.c, the version string was being built by a sequence of
711     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
712     string (as it is for production releases) called a macro with an empty
713     argument. The C standard says the result of this is undefined. The gcc
714     compiler treats it as an empty string (which was what was wanted) but it is
715     reported that Visual C gives an error. The source has been hacked around to
716     avoid this problem.
718     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
719     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
720     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
721     of them did).
723     10. Originally, pcretest opened its input and output without "b"; then I was
724     told that "b" was needed in some environments, so it was added for release
725     5.0 to both the input and output. (It makes no difference on Unix-like
726     systems.) Later I was told that it is wrong for the input on Windows. I've
727     now abstracted the modes into two macros, to make it easier to fiddle with
728     them, and removed "b" from the input mode under Windows.
730     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
732     12. Added -help and --help to pcretest as an official way of being reminded
733     of the options.
735     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
736     and pcrecpp.cc because they annoy compilers at high warning levels.
738     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
740     15. Fixed an occurrence of == in configure.ac that should have been = (shell
741     scripts are not C programs :-) and which was not noticed because it works
742     on Linux.
744     16. pcretest is supposed to handle any length of pattern and data line (as one
745     line or as a continued sequence of lines) by extending its input buffer if
746     necessary. This feature was broken for very long pattern lines, leading to
747     a string of junk being passed to pcre_compile() if the pattern was longer
748     than about 50K.
750     17. I have done a major re-factoring of the way pcre_compile() computes the
751     amount of memory needed for a compiled pattern. Previously, there was code
752     that made a preliminary scan of the pattern in order to do this. That was
753     OK when PCRE was new, but as the facilities have expanded, it has become
754     harder and harder to keep it in step with the real compile phase, and there
755     have been a number of bugs (see for example, 4 above). I have now found a
756     cunning way of running the real compile function in a "fake" mode that
757     enables it to compute how much memory it would need, while actually only
758     ever using a few hundred bytes of working memory and without too many
759     tests of the mode. This should make future maintenance and development
760     easier. A side effect of this work is that the limit of 200 on the nesting
761     depth of parentheses has been removed (though this was never a serious
762     limitation, I suspect). However, there is a downside: pcre_compile() now
763     runs more slowly than before (30% or more, depending on the pattern). I
764     hope this isn't a big issue. There is no effect on runtime performance.
766     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
767     newline (only possible for the last line of a file) and it was a
768     pattern that set a locale (followed by /Lsomething), pcretest crashed.
770     19. Added additional timing features to pcretest. (1) The -tm option now times
771     matching only, not compiling. (2) Both -t and -tm can be followed, as a
772     separate command line item, by a number that specifies the number of
773     repeats to use when timing. The default is 50000; this gives better
774     precision, but takes uncomfortably long for very large patterns.
776     20. Extended pcre_study() to be more clever in cases where a branch of a
777     subpattern has no definite first character. For example, (a*|b*)[cd] would
778     previously give no result from pcre_study(). Now it recognizes that the
779     first character must be a, b, c, or d.
781     21. There was an incorrect error "recursive call could loop indefinitely" if
782     a subpattern (or the entire pattern) that was being tested for matching an
783     empty string contained only one non-empty item after a nested subpattern.
784     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
785     incorrectly, because the \d was being skipped in the check.
787     22. The pcretest program now has a new pattern option /B and a command line
788     option -b, which is equivalent to adding /B to every pattern. This causes
789     it to show the compiled bytecode, without the additional information that
790     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
791     is the same as /B/I).
793     23. A new optimization is now able automatically to treat some sequences such
794     as a*b as a*+b. More specifically, if something simple (such as a character
795     or a simple class like \d) has an unlimited quantifier, and is followed by
796     something that cannot possibly match the quantified thing, the quantifier
797     is automatically "possessified".
799     24. A recursive reference to a subpattern whose number was greater than 39
800     went wrong under certain circumstances in UTF-8 mode. This bug could also
801     have affected the operation of pcre_study().
803     25. Realized that a little bit of performance could be had by replacing
804     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
806     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
808     27. Possessive quantifiers such as a++ were previously implemented by turning
809     them into atomic groups such as ($>a+). Now they have their own opcodes,
810     which improves performance. This includes the automatically created ones
811     from 23 above.
813     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
814     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
815     the first matched character to be a colon. This applied both to named and
816     numbered groups.
818     29. The ucpinternal.h header file was missing its idempotency #ifdef.
820     30. I was sent a "project" file called libpcre.a.dev which I understand makes
821     building PCRE on Windows easier, so I have included it in the distribution.
823     31. There is now a check in pcretest against a ridiculously large number being
824     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
825     loop, the loop is abandoned.
827     32. Forward references to subpatterns in conditions such as (?(2)...) where
828     subpattern 2 is defined later cause pcre_compile() to search forwards in
829     the pattern for the relevant set of parentheses. This search went wrong
830     when there were unescaped parentheses in a character class, parentheses
831     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
833     33. "Subroutine" calls and backreferences were previously restricted to
834     referencing subpatterns earlier in the regex. This restriction has now
835     been removed.
837     34. Added a number of extra features that are going to be in Perl 5.10. On the
838     whole, these are just syntactic alternatives for features that PCRE had
839     previously implemented using the Python syntax or my own invention. The
840     other formats are all retained for compatibility.
842     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
843     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
844     also .NET compatible.
846     (b) A recursion or subroutine call to a named group can now be defined as
847     (?&name) as well as (?P>name).
849     (c) A backreference to a named group can now be defined as \k<name> or
850     \k'name' as well as (?P=name). The new forms, as well as being in Perl
851     5.10, are also .NET compatible.
853     (d) A conditional reference to a named group can now use the syntax
854     (?(<name>) or (?('name') as well as (?(name).
856     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
857     groups (named and numbered) that are never evaluated inline, but can be
858     called as "subroutines" from elsewhere. In effect, the DEFINE condition
859     is always false. There may be only one alternative in such a group.
861     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
862     as the simple (?(R). The condition is true only if the most recent
863     recursion is that of the given number or name. It does not search out
864     through the entire recursion stack.
866     (g) The escape \gN or \g{N} has been added, where N is a positive or
867     negative number, specifying an absolute or relative reference.
869     35. Tidied to get rid of some further signed/unsigned compiler warnings and
870     some "unreachable code" warnings.
872     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
873     things, this adds five new scripts.
875     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
876     There were also incompatibilities regarding the handling of \Q..\E inside
877     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
878     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
880     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
881     matches an empty string, and forcibly breaks the loop. There were bugs in
882     this code in non-simple cases. For a pattern such as ^(a()*)* matched
883     against aaaa the result was just "a" rather than "aaaa", for example. Two
884     separate and independent bugs (that affected different cases) have been
885     fixed.
887     39. Refactored the code to abolish the use of different opcodes for small
888     capturing bracket numbers. This is a tidy that I avoided doing when I
889     removed the limit on the number of capturing brackets for 3.5 back in 2001.
890     The new approach is not only tidier, it makes it possible to reduce the
891     memory needed to fix the previous bug (38).
893     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
894     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
895     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
896     mode.
898     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
899     report.
901     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
902     copy construction and assignment in the C++ wrapper.
904     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
905     couple of bugs that could have given wrong results in the "--newline=crlf"
906     case.
908     44. Added a number of casts and did some reorganization of signed/unsigned int
909     variables following suggestions from Dair Grant. Also renamed the variable
910     "this" as "item" because it is a C++ keyword.
912     45. Arranged for dftables to add
914     #include "pcre_internal.h"
916     to pcre_chartables.c because without it, gcc 4.x may remove the array
917     definition from the final binary if PCRE is built into a static library and
918     dead code stripping is activated.
920     46. For an unanchored pattern, if a match attempt fails at the start of a
921     newline sequence, and the newline setting is CRLF or ANY, and the next two
922     characters are CRLF, advance by two characters instead of one.
925 nigel 91 Version 6.7 04-Jul-06
926     ---------------------
928     1. In order to handle tests when input lines are enormously long, pcretest has
929     been re-factored so that it automatically extends its buffers when
930     necessary. The code is crude, but this _is_ just a test program. The
931     default size has been increased from 32K to 50K.
933     2. The code in pcre_study() was using the value of the re argument before
934     testing it for NULL. (Of course, in any sensible call of the function, it
935     won't be NULL.)
937     3. The memmove() emulation function in pcre_internal.h, which is used on
938     systems that lack both memmove() and bcopy() - that is, hardly ever -
939     was missing a "static" storage class specifier.
941     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
942     containing an extended class (one that cannot be represented by a bitmap
943     because it contains high-valued characters or Unicode property items, e.g.
944     [\pZ]). Almost always one would set UTF-8 mode when processing such a
945     pattern, but PCRE should not loop if you do not (it no longer does).
946     [Detail: two cases were found: (a) a repeated subpattern containing an
947     extended class; (b) a recursive reference to a subpattern that followed a
948     previous extended class. It wasn't skipping over the extended class
949     correctly when UTF-8 mode was not set.]
951     5. A negated single-character class was not being recognized as fixed-length
952     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
953     compile error "lookbehind assertion is not fixed length".
955     6. The RunPerlTest auxiliary script was showing an unexpected difference
956     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
957     write a Perl script that can interpret lines of an input file either as
958     byte characters or as UTF-8, which is what "perltest" was being required to
959     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
960     can't do is switch easily at run time between having the "use utf8;" pragma
961     or not. In the end, I fudged it by using the RunPerlTest script to insert
962     "use utf8;" explicitly for the UTF-8 tests.
964     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
965     the end of the subject string, contrary to the documentation and to what
966     Perl does. This was true of both matching functions. Now it matches only at
967     the start of the subject and immediately after *internal* newlines.
969     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
970     a pointer to an int instead of a pointer to an unsigned long int. This
971     caused problems on 64-bit systems.
973     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
974     instance of the 'standard' template library not being so standard".
976     10. There was no check on the number of named subpatterns nor the maximum
977     length of a subpattern name. The product of these values is used to compute
978     the size of the memory block for a compiled pattern. By supplying a very
979     long subpattern name and a large number of named subpatterns, the size
980     computation could be caused to overflow. This is now prevented by limiting
981     the length of names to 32 characters, and the number of named subpatterns
982     to 10,000.
984     11. Subpatterns that are repeated with specific counts have to be replicated in
985     the compiled pattern. The size of memory for this was computed from the
986     length of the subpattern and the repeat count. The latter is limited to
987     65535, but there was no limit on the former, meaning that integer overflow
988     could in principle occur. The compiled length of a repeated subpattern is
989     now limited to 30,000 bytes in order to prevent this.
991     12. Added the optional facility to have named substrings with the same name.
993     13. Added the ability to use a named substring as a condition, using the
994     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
995     are numbers (not recommended). Forward references are permitted.
997     14. Added forward references in named backreferences (if you see what I mean).
999     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1000     pattern could run off the end of the subject. For example, the pattern
1001     "(?s)(.{1,5})"8 did this with the subject "ab".
1003     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1004     PCRE_CASELESS was set when matching characters that were quantified with ?
1005     or *.
1007     17. A character class other than a single negated character that had a minimum
1008     but no maximum quantifier - for example [ab]{6,} - was not handled
1009     correctly by pce_dfa_exec(). It would match only one character.
1011     18. A valid (though odd) pattern that looked like a POSIX character
1012     class but used an invalid character after [ (for example [[,abc,]]) caused
1013     pcre_compile() to give the error "Failed: internal error: code overflow" or
1014     in some cases to crash with a glibc free() error. This could even happen if
1015     the pattern terminated after [[ but there just happened to be a sequence of
1016     letters, a binary zero, and a closing ] in the memory that followed.
1018     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1019     over the years. Originally (before any Unicode support), just the bottom 8
1020     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1021     output from "man perlunicode" includes this:
1023     The regular expression compiler produces polymorphic opcodes. That
1024     is, the pattern adapts to the data and automatically switches to
1025     the Unicode character scheme when presented with Unicode data--or
1026     instead uses a traditional byte scheme when presented with byte
1027     data.
1029     Sadly, a wide octal escape does not cause a switch, and in a string with
1030     no other multibyte characters, these octal escapes are treated as before.
1031     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1032     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1033     Unicode string.
1035     I have not perpetrated such confusion in PCRE. Up till now, it took just
1036     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1037     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1038     translate to the appropriate multibyte character.
1040     29. Applied some refactoring to reduce the number of warnings from Microsoft
1041     and Borland compilers. This has included removing the fudge introduced
1042     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1043     a warning about an unused variable.
1045     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1046     characters since release 4.0, because Perl (from release 5.004) does not.
1047     [Or at least, is documented not to: some releases seem to be in conflict
1048     with the documentation.] However, when a pattern was studied with
1049     pcre_study() and all its branches started with \s, PCRE still included VT
1050     as a possible starting character. Of course, this did no harm; it just
1051     caused an unnecessary match attempt.
1053     22. Removed a now-redundant internal flag bit that recorded the fact that case
1054     dependency changed within the pattern. This was once needed for "required
1055     byte" processing, but is no longer used. This recovers a now-scarce options
1056     bit. Also moved the least significant internal flag bit to the most-
1057     significant bit of the word, which was not previously used (hangover from
1058     the days when it was an int rather than a uint) to free up another bit for
1059     the future.
1061     23. Added support for CRLF line endings as well as CR and LF. As well as the
1062     default being selectable at build time, it can now be changed at runtime
1063     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1064     specify that it is scanning data with non-default line endings.
1066     24. Changed the definition of CXXLINK to make it agree with the definition of
1067     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1069     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1070     recursions. This makes a big different to stack usage for some patterns.
1072     26. If a subpattern containing a named recursion or subroutine reference such
1073     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1074     the space required for the compiled pattern went wrong and gave too small a
1075     value. Depending on the environment, this could lead to "Failed: internal
1076     error: code overflow at offset 49" or "glibc detected double free or
1077     corruption" errors.
1079     27. Applied patches from Google (a) to support the new newline modes and (b) to
1080     advance over multibyte UTF-8 characters in GlobalReplace.
1082     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1083     difference for some implementation of PCRE in some Windows version.
1085     29. Added some extra testing facilities to pcretest:
1087     \q<number> in a data line sets the "match limit" value
1088     \Q<number> in a data line sets the "match recursion limt" value
1089     -S <number> sets the stack size, where <number> is in megabytes
1091     The -S option isn't available for Windows.
1094 nigel 89 Version 6.6 06-Feb-06
1095     ---------------------
1097     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1098     in pcreposix.h. I have copied the definition from pcre.h.
1100     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1101     because pcre.h is no longer a built file.
1103     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1104     not normally included in the compiled code.
1107 nigel 87 Version 6.5 01-Feb-06
1108     ---------------------
1110     1. When using the partial match feature with pcre_dfa_exec(), it was not
1111     anchoring the second and subsequent partial matches at the new starting
1112     point. This could lead to incorrect results. For example, with the pattern
1113     /1234/, partially matching against "123" and then "a4" gave a match.
1115     2. Changes to pcregrep:
1117     (a) All non-match returns from pcre_exec() were being treated as failures
1118     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1119     error message is output. Some extra information is given for the
1121     probably the only errors that are likely to be caused by users (by
1122     specifying a regex that has nested indefinite repeats, for instance).
1123     If there are more than 20 of these errors, pcregrep is abandoned.
1125     (b) A binary zero was treated as data while matching, but terminated the
1126     output line if it was written out. This has been fixed: binary zeroes
1127     are now no different to any other data bytes.
1129     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1130     used to set a locale for matching. The --locale=xxxx long option has
1131     been added (no short equivalent) to specify a locale explicitly on the
1132     pcregrep command, overriding the environment variables.
1134     (d) When -B was used with -n, some line numbers in the output were one less
1135     than they should have been.
1137     (e) Added the -o (--only-matching) option.
1139     (f) If -A or -C was used with -c (count only), some lines of context were
1140     accidentally printed for the final match.
1142     (g) Added the -H (--with-filename) option.
1144     (h) The combination of options -rh failed to suppress file names for files
1145     that were found from directory arguments.
1147     (i) Added the -D (--devices) and -d (--directories) options.
1149     (j) Added the -F (--fixed-strings) option.
1151     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1153     (l) Added the --colo(u)r option.
1155     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1156     is not present by default.
1158     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1159     items such as (?R) or (?1), when the recursion could match a number of
1160     alternatives. If it matched one of the alternatives, but subsequently,
1161     outside the recursion, there was a failure, the code tried to back up into
1162     the recursion. However, because of the way PCRE is implemented, this is not
1163     possible, and the result was an incorrect result from the match.
1165     In order to prevent this happening, the specification of recursion has
1166     been changed so that all such subpatterns are automatically treated as
1167     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1169     4. I had overlooked the fact that, in some locales, there are characters for
1170     which isalpha() is true but neither isupper() nor islower() are true. In
1171     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1172     and ordfeminine) are like this. This affected the treatment of \w and \W
1173     when they appeared in character classes, but not when they appeared outside
1174     a character class. The bit map for "word" characters is now created
1175     separately from the results of isalnum() instead of just taking it from the
1176     upper, lower, and digit maps. (Plus the underscore character, of course.)
1178     5. The above bug also affected the handling of POSIX character classes such as
1179     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1180     permanent tables. Instead, the bit maps for such a class were previously
1181     created as the appropriate unions of the upper, lower, and digit bitmaps.
1182     Now they are created by subtraction from the [[:word:]] class, which has
1183     its own bitmap.
1185     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1186     It is created by subtracting the vertical space characters (\x09, \x0a,
1187     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1188     subtraction was done in the overall bitmap for a character class, meaning
1189     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1190     be recognized. This bug has been fixed.
1192     7. Patches from the folks at Google:
1194     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1195     real life, but is still worth protecting against".
1197     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1198     regular expressions".
1200     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1201     have it.
1203     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1204     "configure" and the latter not, in order to fix a problem somebody had
1205     with compiling the Arg class on HP-UX.
1207     (e) Improve the error-handling of the C++ wrapper a little bit.
1209     (f) New tests for checking recursion limiting.
1211     8. The pcre_memmove() function, which is used only if the environment does not
1212     have a standard memmove() function (and is therefore rarely compiled),
1213     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1214     returning a result (though PCRE never actually uses the result).
1216     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1217     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1218     returned instead of calling malloc() with an overflowing number that would
1219     most likely cause subsequent chaos.
1221     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1223     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1224     with this option is matched, the nmatch and pmatch options of regexec() are
1225     ignored.
1227     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1228     provided in case anyone wants to the the POSIX interface with UTF-8
1229     strings.
1231     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1232     C++ linking (needed for some HP-UX environments).
1234     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1235     (unused parameter) and in the pcre_printint() function (omitted "default"
1236     switch label when the default is to do nothing).
1238     15. Added some code to make it possible, when PCRE is compiled as a C++
1239     library, to replace subject pointers for pcre_exec() with a smart pointer
1240     class, thus making it possible to process discontinuous strings.
1242     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1243     much the same function. They were added by different people who were trying
1244     to make PCRE easy to compile on non-Unix systems. It has been suggested
1245     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1246     for compiling on Windows systems. I have therefore replaced it with
1247     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1248     defaults to "extern" for C or "extern C" for C++, which works fine on
1249     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1250     SCOPE with something explicit in config.h. In addition:
1252     (a) pcreposix.h still had just "extern" instead of either of these macros;
1253     I have replaced it with PCRE_DATA_SCOPE.
1255     (b) Functions such as _pcre_xclass(), which are internal to the library,
1256     but external in the C sense, all had PCRE_EXPORT in their definitions.
1257     This is apparently wrong for the Windows case, so I have removed it.
1258     (It makes no difference on Unix-like systems.)
1260     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1261     of recursive calls to match(). This is different to MATCH_LIMIT because
1262     that limits the total number of calls to match(), not all of which increase
1263     the depth of recursion. Limiting the recursion depth limits the amount of
1264     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1265     when PCRE is compiled, and changed at run time. A patch from Google adds
1266     this functionality to the C++ interface.
1268     18. Changes to the handling of Unicode character properties:
1270     (a) Updated the table to Unicode 4.1.0.
1272     (b) Recognize characters that are not in the table as "Cn" (undefined).
1274     (c) I revised the way the table is implemented to a much improved format
1275     which includes recognition of ranges. It now supports the ranges that
1276     are defined in UnicodeData.txt, and it also amalgamates other
1277     characters into ranges. This has reduced the number of entries in the
1278     table from around 16,000 to around 3,000, thus reducing its size
1279     considerably. I realized I did not need to use a tree structure after
1280     all - a binary chop search is just as efficient. Having reduced the
1281     number of entries, I extended their size from 6 bytes to 8 bytes to
1282     allow for more data.
1284     (d) Added support for Unicode script names via properties such as \p{Han}.
1286     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1287     matching that character.
1289     20. When matching a repeated Unicode property with a minimum greater than zero,
1290     (for example \pL{2,}), PCRE could look past the end of the subject if it
1291     reached it while seeking the minimum number of characters. This could
1292     happen only if some of the characters were more than one byte long, because
1293     there is a check for at least the minimum number of bytes.
1295     21. Refactored the implementation of \p and \P so as to be more general, to
1296     allow for more different types of property in future. This has changed the
1297     compiled form incompatibly. Anybody with saved compiled patterns that use
1298     \p or \P will have to recompile them.
1300     22. Added "Any" and "L&" to the supported property types.
1302     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1303     but give a compile time error if the value is greater than 0xff.
1305     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1306     accidentally not being installed or uninstalled.
1308     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1309     made were to insert the current release number. This seemed silly, because
1310     it made things harder for people building PCRE on systems that don't run
1311     "configure". I have turned pcre.h into a distributed file, no longer built
1312     by "configure", with the version identification directly included. There is
1313     no longer a pcre.h.in file.
1315     However, this change necessitated a change to the pcre-config script as
1316     well. It is built from pcre-config.in, and one of the substitutions was the
1317     release number. I have updated configure.ac so that ./configure now finds
1318     the release number by grepping pcre.h.
1320     26. Added the ability to run the tests under valgrind.
1323 nigel 85 Version 6.4 05-Sep-05
1324     ---------------------
1326     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1327     "--" to be printed when multiple files were scanned, even when none of the
1328     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1329     consider it to be a bug, and have restored the previous behaviour.
1331     2. A couple of code tidies to get rid of compiler warnings.
1333     3. The pcretest program used to cheat by referring to symbols in the library
1334     whose names begin with _pcre_. These are internal symbols that are not
1335     really supposed to be visible externally, and in some environments it is
1336     possible to suppress them. The cheating is now confined to including
1337     certain files from the library's source, which is a bit cleaner.
1339     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1340     file's purpose clearer.
1342     5. Reorganized pcre_ucp_findchar().
1345 nigel 83 Version 6.3 15-Aug-05
1346     ---------------------
1348     1. The file libpcre.pc.in did not have general read permission in the tarball.
1350     2. There were some problems when building without C++ support:
1352     (a) If C++ support was not built, "make install" and "make test" still
1353     tried to test it.
1355     (b) There were problems when the value of CXX was explicitly set. Some
1356     changes have been made to try to fix these, and ...
1358     (c) --disable-cpp can now be used to explicitly disable C++ support.
1360     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1361     backslash in a target when C++ was disabled. This confuses some
1362     versions of "make", apparently. Using an intermediate variable solves
1363     this. (Same for CPP_LOBJ.)
1365     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1366     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1367     necessary on certain architectures.
1369     4. Added a setting of -export-symbols-regex to the link command to remove
1370     those symbols that are exported in the C sense, but actually are local
1371     within the library, and not documented. Their names all begin with
1372     "_pcre_". This is not a perfect job, because (a) we have to except some
1373     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1374     available (and never for static libraries). I have made a note to try to
1375     find a way round (a) in the future.
1378 nigel 81 Version 6.2 01-Aug-05
1379     ---------------------
1381     1. There was no test for integer overflow of quantifier values. A construction
1382     such as {1111111111111111} would give undefined results. What is worse, if
1383     a minimum quantifier for a parenthesized subpattern overflowed and became
1384     negative, the calculation of the memory size went wrong. This could have
1385     led to memory overwriting.
1387     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1389     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1390     operating environments where this matters.
1392     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1393     PCRE options from within the C++ wrapper.
1395     5. Named capturing subpatterns were not being correctly counted when a pattern
1396     was compiled. This caused two problems: (a) If there were more than 100
1397     such subpatterns, the calculation of the memory needed for the whole
1398     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1399     back references of the form \12, where the number was greater than 9, were
1400     not recognized as back references, even though there were sufficient
1401     previous subpatterns.
1403     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1404     versions of gcc, e.g. 2.95.4.
1407 nigel 79 Version 6.1 21-Jun-05
1408     ---------------------
1410     1. There was one reference to the variable "posix" in pcretest.c that was not
1411     surrounded by "#if !defined NOPOSIX".
1413     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1414     the cross-check on the old pcre_info() function, for the benefit of the
1415     cut-down version of PCRE that is currently imported into Exim.
1417     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1418     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1419     patterns that start (?i) but I don't think that matters. The use of (?i) is
1420     just an example; this all applies to the other options as well.
1422     4. Since libtool seems to echo the compile commands it is issuing, the output
1423     from "make" can be reduced a bit by putting "@" in front of each libtool
1424     compile command.
1426     5. Patch from the folks at Google for configure.in to be a bit more thorough
1427     in checking for a suitable C++ installation before trying to compile the
1428     C++ stuff. This should fix a reported problem when a compiler was present,
1429     but no suitable headers.
1431     6. The man pages all had just "PCRE" as their title. I have changed them to
1432     be the relevant file name. I have also arranged that these names are
1433     retained in the file doc/pcre.txt, which is a concatenation in text format
1434     of all the man pages except the little individual ones for each function.
1436     7. The NON-UNIX-USE file had not been updated for the different set of source
1437     files that come with release 6. I also added a few comments about the C++
1438     wrapper.
1441 nigel 77 Version 6.0 07-Jun-05
1442     ---------------------
1444     1. Some minor internal re-organization to help with my DFA experiments.
1446     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1447     didn't matter for the library itself when fully configured, but did matter
1448     when compiling without UCP support, or within Exim, where the ucp files are
1449     not imported.
1451     3. Refactoring of the library code to split up the various functions into
1452     different source modules. The addition of the new DFA matching code (see
1453     below) to a single monolithic source would have made it really too
1454     unwieldy, quite apart from causing all the code to be include in a
1455     statically linked application, when only some functions are used. This is
1456     relevant even without the DFA addition now that patterns can be compiled in
1457     one application and matched in another.
1459     The downside of splitting up is that there have to be some external
1460     functions and data tables that are used internally in different modules of
1461     the library but which are not part of the API. These have all had their
1462     names changed to start with "_pcre_" so that they are unlikely to clash
1463     with other external names.
1465     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1466     a different (DFA) algorithm. Although it is slower than the original
1467     function, it does have some advantages for certain types of matching
1468     problem.
1470     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1471     including restarting after a partial match.
1473     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1474     defined when compiling for Windows was sent to me. I have put it into the
1475     code, though I have no means of testing or verifying it.
1477     7. Added the pcre_refcount() auxiliary function.
1479     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1480     match before or at the first newline in the subject string. In pcretest,
1481     the /f option on a pattern can be used to set this.
1483     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1484     would behave wrongly. This has been present in PCRE since release 4.0.
1486     10. A number of changes to the pcregrep command:
1488     (a) Refactored how -x works; insert ^(...)$ instead of setting
1489     PCRE_ANCHORED and checking the length, in preparation for adding
1490     something similar for -w.
1492     (b) Added the -w (match as a word) option.
1494     (c) Refactored the way lines are read and buffered so as to have more
1495     than one at a time available.
1497     (d) Implemented a pcregrep test script.
1499     (e) Added the -M (multiline match) option. This allows patterns to match
1500     over several lines of the subject. The buffering ensures that at least
1501     8K, or the rest of the document (whichever is the shorter) is available
1502     for matching (and similarly the previous 8K for lookbehind assertions).
1504     (f) Changed the --help output so that it now says
1506     -w, --word-regex(p)
1508     instead of two lines, one with "regex" and the other with "regexp"
1509     because that confused at least one person since the short forms are the
1510     same. (This required a bit of code, as the output is generated
1511     automatically from a table. It wasn't just a text change.)
1513     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1514     option but starts with a hyphen. Could be a pattern or a path name
1515     starting with a hyphen, for instance.
1517     (h) "-" can be given as a file name to represent stdin.
1519     (i) When file names are being printed, "(standard input)" is used for
1520     the standard input, for compatibility with GNU grep. Previously
1521     "<stdin>" was used.
1523     (j) The option --label=xxx can be used to supply a name to be used for
1524     stdin when file names are being printed. There is no short form.
1526     (k) Re-factored the options decoding logic because we are going to add
1527     two more options that take data. Such options can now be given in four
1528     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1530     (l) Added the -A, -B, and -C options for requesting that lines of context
1531     around matches be printed.
1533     (m) Added the -L option to print the names of files that do not contain
1534     any matching lines, that is, the complement of -l.
1536     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1537     continue to scan other files.
1539     (o) The -s option was incorrectly implemented. For compatibility with other
1540     greps, it now suppresses the error message for a non-existent or non-
1541     accessible file (but not the return code). There is a new option called
1542     -q that suppresses the output of matching lines, which was what -s was
1543     previously doing.
1545     (p) Added --include and --exclude options to specify files for inclusion
1546     and exclusion when recursing.
1548     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1549     Hopefully, it now does.
1551     12. Missing cast in pcre_study().
1553     13. Added an "uninstall" target to the makefile.
1555     14. Replaced "extern" in the function prototypes in Makefile.in with
1556     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1557     world, but is set differently for Windows.
1559     15. Added a second compiling function called pcre_compile2(). The only
1560     difference is that it has an extra argument, which is a pointer to an
1561     integer error code. When there is a compile-time failure, this is set
1562     non-zero, in addition to the error test pointer being set to point to an
1563     error message. The new argument may be NULL if no error number is required
1564     (but then you may as well call pcre_compile(), which is now just a
1565     wrapper). This facility is provided because some applications need a
1566     numeric error indication, but it has also enabled me to tidy up the way
1567     compile-time errors are handled in the POSIX wrapper.
1569     16. Added VPATH=.libs to the makefile; this should help when building with one
1570     prefix path and installing with another. (Or so I'm told by someone who
1571     knows more about this stuff than I do.)
1573     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1574     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1575     match everything, including newlines. This is not POSIX-compatible, but
1576     somebody wanted the feature. From pcretest it can be activated by using
1577     both the P and the s flags.
1579     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1581     19. libpcre.pc was being incorrectly installed as executable.
1583     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1584     it now also looks for '\r' so that it will work unmodified on Windows.
1586     21. Added Google's contributed C++ wrapper to the distribution.
1588     22. Added some untidy missing memory free() calls in pcretest, to keep
1589     Electric Fence happy when testing.
1593 nigel 75 Version 5.0 13-Sep-04
1594     ---------------------
1596     1. Internal change: literal characters are no longer packed up into items
1597     containing multiple characters in a single byte-string. Each character
1598     is now matched using a separate opcode. However, there may be more than one
1599     byte in the character in UTF-8 mode.
1601     2. The pcre_callout_block structure has two new fields: pattern_position and
1602     next_item_length. These contain the offset in the pattern to the next match
1603     item, and its length, respectively.
1605     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1606     insertion of callouts before each pattern item. Added the /C option to
1607     pcretest to make use of this.
1609     4. On the advice of a Windows user, the lines
1611     #if defined(_WIN32) || defined(WIN32)
1612     _setmode( _fileno( stdout ), 0x8000 );
1613     #endif /* defined(_WIN32) || defined(WIN32) */
1615     have been added to the source of pcretest. This apparently does useful
1616     magic in relation to line terminators.
1618     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1619     for the benefit of those environments where the "b" makes a difference.
1621     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1622     to know about it. I have put a hack into configure.in that adds in code
1623     to set GCC=yes if CC=icc. This seems to end up at a point in the
1624     generated configure script that is early enough to affect the setting of
1625     compiler options, which is what is needed, but I have no means of testing
1626     whether it really works. (The user who reported this had patched the
1627     generated configure script, which of course I cannot do.)
1629     LATER: After change 22 below (new libtool files), the configure script
1630     seems to know about icc (and also ecc). Therefore, I have commented out
1631     this hack in configure.in.
1633     7. Added support for pkg-config (2 patches were sent in).
1635     8. Negated POSIX character classes that used a combination of internal tables
1636     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1637     [[:^ascii]]. Typically, they would match almost any characters. The other
1638     POSIX classes were not broken in this way.
1640     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1641     to find the match, as PCRE was deluded into thinking that the match had to
1642     start at the start point or following a newline. The same bug applied to
1643     patterns with negative forward assertions or any backward assertions
1644     preceding ".*" at the start, unless the pattern required a fixed first
1645     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1647     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1648     starting at the last subject character, bytes beyond the end of the subject
1649     string were read.
1651     11. Renamed the variable "class" as "classbits" to make life easier for C++
1652     users. (Previously there was a macro definition, but it apparently wasn't
1653     enough.)
1655     12. Added the new field "tables" to the extra data so that tables can be passed
1656     in at exec time, or the internal tables can be re-selected. This allows
1657     a compiled regex to be saved and re-used at a later time by a different
1658     program that might have everything at different addresses.
1660     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1661     -R library as well as a -L library.
1663     14. The debugging options of pcretest (-d on the command line or D on a
1664     pattern) showed incorrect output for anything following an extended class
1665     that contained multibyte characters and which was followed by a quantifier.
1667     15. Added optional support for general category Unicode character properties
1668     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1669     support. It adds about 90K to the size of the library. The meanings of the
1670     inbuilt class escapes such as \d and \s have NOT been changed.
1672     16. Updated pcredemo.c to include calls to free() to release the memory for the
1673     compiled pattern.
1675     17. The generated file chartables.c was being created in the source directory
1676     instead of in the building directory. This caused the build to fail if the
1677     source directory was different from the building directory, and was
1678     read-only.
1680     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1681     file. No doubt somebody will tell me if they don't make sense... Also added
1682     Dan Mooney's comments about building on OpenVMS.
1684     19. Added support for partial matching via the PCRE_PARTIAL option for
1685     pcre_exec() and the \P data escape in pcretest.
1687     20. Extended pcretest with 3 new pattern features:
1689     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1690     write the compiled pattern to the file whose name is "rest-of-line".
1691     This is a straight binary dump of the data, with the saved pointer to
1692     the character tables forced to be NULL. The study data, if any, is
1693     written too. After writing, pcretest reads a new pattern.
1695     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1696     compiled pattern from the given file. There must not be any
1697     occurrences of "<" in the file name (pretty unlikely); if there are,
1698     pcretest will instead treat the initial "<" as a pattern delimiter.
1699     After reading in the pattern, pcretest goes on to read data lines as
1700     usual.
1702     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1703     and 16-bit fields in a compiled pattern, to simulate a pattern that
1704     was compiled on a host of opposite endianness.
1706     21. The pcre-exec() function can now cope with patterns that were compiled on
1707     hosts of opposite endianness, with this restriction:
1709     As for any compiled expression that is saved and used later, the tables
1710     pointer field cannot be preserved; the extra_data field in the arguments
1711     to pcre_exec() should be used to pass in a tables address if a value
1712     other than the default internal tables were used at compile time.
1714     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1715     now diagnosed as an error. Previously, most of the time, a negative number
1716     would have been treated as zero, but if in addition "ovector" was passed as
1717     NULL, a crash could occur.
1719     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1720     new versions from the libtool 1.5 distribution (the last one is a copy of
1721     a file called libtool.m4). This seems to have fixed the need to patch
1722     "configure" to support Darwin 1.3 (which I used to do). However, I still
1723     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1724     workstation).
1726     24. Changed the PCRE licence to be the more standard "BSD" licence.
1729 nigel 73 Version 4.5 01-Dec-03
1730     ---------------------
1732     1. There has been some re-arrangement of the code for the match() function so
1733     that it can be compiled in a version that does not call itself recursively.
1734     Instead, it keeps those local variables that need separate instances for
1735     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1736     needs to "recurse". Keeping track of where control must go is done by means
1737     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1738     hide most of the details from the main code, and operates only if
1739     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1740     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1741     operating.
1743     To make it easier for callers to provide specially tailored get/free
1744     functions for this usage, two new functions, pcre_stack_malloc, and
1745     pcre_stack_free, are used. They are always called in strict stacking order,
1746     and the size of block requested is always the same.
1748     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1749     PCRE has been compiled to use the stack or the heap for recursion. The
1750     -C option of pcretest uses this to show which version is compiled.
1752     A new data escape \S, is added to pcretest; it causes the amounts of store
1753     obtained and freed by both kinds of malloc/free at match time to be added
1754     to the output.
1756     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1757     what's available on my current Linux desktop machine.
1759     3. When matching a UTF-8 string, the test for a valid string at the start has
1760     been extended. If start_offset is not zero, PCRE now checks that it points
1761     to a byte that is the start of a UTF-8 character. If not, it returns
1762     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1763     this is necessary because there may be backward assertions in the pattern.
1764     When matching the same subject several times, it may save resources to use
1765     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1767     4. The code for checking the validity of UTF-8 strings has been tightened so
1768     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1769     containing "overlong sequences".
1771     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1772     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1773     should have been "&", but it just so happened that all the cases this let
1774     through by mistake were picked up later in the function.
1776     6. I had used a variable called "isblank" - this is a C99 function, causing
1777     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1779     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1780     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1781     so the version is shown; (c) stop "make test" echoing "./RunTest".
1783     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1785     9. The prototype for memmove() for systems that don't have it was using
1786     size_t, but the inclusion of the header that defines size_t was later. I've
1787     moved the #includes for the C headers earlier to avoid this.
1789     10. Added some adjustments to the code to make it easier to compiler on certain
1790     special systems:
1792     (a) Some "const" qualifiers were missing.
1793     (b) Added the macro EXPORT before all exported functions; by default this
1794     is defined to be empty.
1795     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1796     that it reads its output file name as an argument instead of writing
1797     to the standard output and assuming this can be redirected.
1799     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1800     class containing characters with values greater than 255, PCRE compilation
1801     went into a loop.
1803     12. A recursive reference to a subpattern that was within another subpattern
1804     that had a minimum quantifier of zero caused PCRE to crash. For example,
1805     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1806     recursion. If the recursively-called subpattern itself had a zero repeat,
1807     that was OK.
1809     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1810     buffer into which it was copied (for escape processing) was still set at
1811     1024, so long lines caused crashes.
1813     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1814     "internal error: code overflow...". This applied to any character class
1815     that was followed by a possessive quantifier.
1817     15. Modified the Makefile to add libpcre.la as a prerequisite for
1818     libpcreposix.la because I was told this is needed for a parallel build to
1819     work.
1821     16. If a pattern that contained .* following optional items at the start was
1822     studied, the wrong optimizing data was generated, leading to matching
1823     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1824     matching string must start with a or b or c. The correct conclusion for
1825     this pattern is that a match can start with any character.
1828 nigel 71 Version 4.4 13-Aug-03
1829     ---------------------
1831     1. In UTF-8 mode, a character class containing characters with values between
1832     127 and 255 was not handled correctly if the compiled pattern was studied.
1833     In fixing this, I have also improved the studying algorithm for such
1834     classes (slightly).
1836     2. Three internal functions had redundant arguments passed to them. Removal
1837     might give a very teeny performance improvement.
1839     3. Documentation bug: the value of the capture_top field in a callout is *one
1840     more than* the number of the hightest numbered captured substring.
1842     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1843     in incorrectly linking with a previously installed version. They now link
1844     explicitly with libpcre.la.
1846     5. configure.in no longer needs to recognize Cygwin specially.
1848     6. A problem in pcre.in for Windows platforms is fixed.
1850     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1851     pcretest, it used to include the size of the study block as part of its
1852     output. Unfortunately, the structure contains a field that has a different
1853     size on different hardware architectures. This meant that the tests that
1854     showed this size failed. As the block is currently always of a fixed size,
1855     this information isn't actually particularly useful in pcretest output, so
1856     I have just removed it.
1858     8. Three pre-processor statements accidentally did not start in column 1.
1859     Sadly, there are *still* compilers around that complain, even though
1860     standard C has not required this for well over a decade. Sigh.
1862     9. In pcretest, the code for checking callouts passed small integers in the
1863     callout_data field, which is a void * field. However, some picky compilers
1864     complained about the casts involved for this on 64-bit systems. Now
1865     pcretest passes the address of the small integer instead, which should get
1866     rid of the warnings.
1868     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1869     both compile and run time, and gives an error if an invalid UTF-8 sequence
1870     is found. There is a option for disabling this check in cases where the
1871     string is known to be correct and/or the maximum performance is wanted.
1873     11. In response to a bug report, I changed one line in Makefile.in from
1875     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1876     to
1877     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1879     to look similar to other lines, but I have no way of telling whether this
1880     is the right thing to do, as I do not use Windows. No doubt I'll get told
1881     if it's wrong...
1884 nigel 69 Version 4.3 21-May-03
1885     ---------------------
1887     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1888     Makefile.
1890     2. Some refactoring to improve the quality of the code:
1892     (i) The utf8_table... variables are now declared "const".
1894     (ii) The code for \cx, which used the "case flipping" table to upper case
1895     lower case letters, now just substracts 32. This is ASCII-specific,
1896     but the whole concept of \cx is ASCII-specific, so it seems
1897     reasonable.
1899     (iii) PCRE was using its character types table to recognize decimal and
1900     hexadecimal digits in the pattern. This is silly, because it handles
1901     only 0-9, a-f, and A-F, but the character types table is locale-
1902     specific, which means strange things might happen. A private
1903     table is now used for this - though it costs 256 bytes, a table is
1904     much faster than multiple explicit tests. Of course, the standard
1905     character types table is still used for matching digits in subject
1906     strings against \d.
1908     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1909     ending in _t are). So I've renamed it as ESC_tee.
1911     3. The first argument for regexec() in the POSIX wrapper should have been
1912     defined as "const".
1914     4. Changed pcretest to use malloc() for its buffers so that they can be
1915     Electric Fenced for debugging.
1917     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1918     to read one or more bytes before the start of the subject string. Often this
1919     had no effect on PCRE's behaviour, but in some circumstances it could
1920     provoke a segmentation fault.
1922     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1923     to try to read one or more bytes before the start of the subject string.
1925     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1926     UTF-8 support could misbehave in various ways if the subject string
1927     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1928     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1929     back over UTF-8 characters.)
1932 nigel 67 Version 4.2 14-Apr-03
1933     ---------------------
1935     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1937     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1938     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1939     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1940     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1941     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1942     and BUILD_EXEEXT
1943     Note: automatic setting of the BUILD variables is not yet working
1944     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1945     compile-time but not at link-time
1946     [LINK]: use for linking executables only
1947     make different versions for Windows and non-Windows
1948     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1949     libraries
1950     [LINK_FOR_BUILD]: new variable
1951     [OBJEXT]: use throughout
1952     [EXEEXT]: use throughout
1953     <winshared>: new target
1954     <wininstall>: new target
1955     <dftables.o>: use native compiler
1956     <dftables>: use native linker
1957     <install>: handle Windows platform correctly
1958     <clean>: ditto
1959     <check>: ditto
1960     copy DLL to top builddir before testing
1962     As part of these changes, -no-undefined was removed again. This was reported
1963     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1964     in any case.
1966     3. Some tidies to get rid of compiler warnings:
1968     . In the match_data structure, match_limit was an unsigned long int, whereas
1969     match_call_count was an int. I've made them both unsigned long ints.
1971     . In pcretest the fact that a const uschar * doesn't automatically cast to
1972     a void * provoked a warning.
1974     . Turning on some more compiler warnings threw up some "shadow" variables
1975     and a few more missing casts.
1977     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1978     option, a class that contained a single character with a value between 128
1979     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1981     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1982     option, a class that contained several characters, but with at least one
1983     whose value was between 128 and 255 caused PCRE to crash.
1986 nigel 65 Version 4.1 12-Mar-03
1987     ---------------------
1988 nigel 63
1989 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
1990     needed, and a string in dftables.c that was longer than standard compilers are
1991     required to support.
1993     2. Compiling with Sun's compiler found a few more places where the code could
1994     be tidied up in order to avoid warnings.
1996     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1997     first of these names is deprecated in the latest Autoconf in favour of the name
1998     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1999     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2000     analogy I have changed it to CFLAGS_FOR_BUILD.
2002     4. Added -no-undefined to the linking command in the Makefile, because this is
2003     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2004     linking step for the pcreposix library.
2006     5. PCRE was failing to diagnose the case of two named groups with the same
2007     name.
2009     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2010     literal character that is needed in the subject for a match, and scans along to
2011     ensure that it is present before embarking on the full matching process. This
2012     saves time in cases of nested unlimited repeats that are never going to match.
2013     Problem: the scan can take a lot of time if the subject is very long (e.g.
2014     megabytes), thus penalizing straightforward matches. It is now done only if the
2015     amount of subject to be scanned is less than 1000 bytes.
2017     7. A lesser problem with the same optimization is that it was recording the
2018     first character of an anchored pattern as "needed", thus provoking a search
2019     right along the subject, even when the first match of the pattern was going to
2020     fail. The "needed" character is now not set for anchored patterns, unless it
2021     follows something in the pattern that is of non-fixed length. Thus, it still
2022     fulfils its original purpose of finding quick non-matches in cases of nested
2023     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2026     Version 4.0 17-Feb-03
2027     ---------------------
2029 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2030     extended to the end of string, PCRE compiled incorrect data. This could lead to
2031     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2033     2. Moved to autoconf 2.53 and libtool 1.4.2.
2035     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2036     the special perltest8 script is no longer needed - all the tests can be run
2037     from a single perltest script.
2039     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2040     by \s. It has now been removed in PCRE. This means it isn't recognized as
2041     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2042     class [:space:] *does* include VT, thereby creating a mess.
2044     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2045     space and tab.
2047     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2048     its new features into the main test script, reducing the number of scripts.
2050     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2051     were backward compatible, and made the (?i) apply to the whole pattern, as if
2052     /i were given. Now it behaves more logically, and applies the option setting
2053     only to what follows. PCRE has been changed to follow suit. However, if it
2054     finds options settings right at the start of the pattern, it extracts them into
2055     the global options, as before. Thus, they show up in the info data.
2057     8. Added support for the \Q...\E escape sequence. Characters in between are
2058     treated as literals. This is slightly different from Perl in that $ and @ are
2059     also handled as literals inside the quotes. In Perl, they will cause variable
2060     interpolation. Note the following examples:
2062     Pattern PCRE matches Perl matches
2064     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2065     \Qabc\$xyz\E abc\$xyz abc\$xyz
2066     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2068     For compatibility with Perl, \Q...\E sequences are recognized inside character
2069     classes as well as outside them.
2071     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2072     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2073     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2074     signed/unsigned warnings.
2076     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2077     option for pcretest, so I've replaced it by a simple function that does just
2078     that job.
2080     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2081     "pcregrep -".
2083     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2084     Java package. This provides some syntactic sugar for simple cases of what my
2085     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2086     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2087     item, you can use this simplified notation. Note that only makes sense with
2088     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2089     greediness, whatever the setting of the PCRE_UNGREEDY option.
2091     13. A change of greediness default within a pattern was not taking effect at
2092     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2093     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2094     was abstracted outside.
2096     14. PCRE now supports the \G assertion. It is true when the current matching
2097     position is at the start point of the match. This differs from \A when the
2098     starting offset is non-zero. Used with the /g option of pcretest (or similar
2099     code), it works in the same way as it does for Perl's /g option. If all
2100     alternatives of a regex begin with \G, the expression is anchored to the start
2101     match position, and the "anchored" flag is set in the compiled expression.
2103     15. Some bugs concerning the handling of certain option changes within patterns
2104     have been fixed. These applied to options other than (?ims). For example,
2105     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2106     been the other way round. Some of this was related to change 7 above.
2108     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2109     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2110     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2111     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2113     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2114     mode. Unlike ".", it always matches newline, whatever the setting of
2115     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2116     assertions. Perl allows it, but it doesn't (in general) work because it can't
2117     calculate the length of the lookbehind. At least, that's the case for Perl
2118     5.8.0 - I've been told they are going to document that it doesn't work in
2119     future.
2121     18. Added an error diagnosis for escapes that PCRE does not support: these are
2122     \L, \l, \N, \P, \p, \U, \u, and \X.
2124     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2125     reading past the end of the pattern in cases such as /[abcd/.
2127     20. PCRE was getting more memory than necessary for patterns with classes that
2128     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2130     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2131     compiling PCRE for use with Virtual Pascal.
2133     22. Small fix to the Makefile to make it work properly if the build is done
2134     outside the source tree.
2136     23. Added a new extension: a condition to go with recursion. If a conditional
2137     subpattern starts with (?(R) the "true" branch is used if recursion has
2138     happened, whereas the "false" branch is used only at the top level.
2140     24. When there was a very long string of literal characters (over 255 bytes
2141     without UTF support, over 250 bytes with UTF support), the computation of how
2142     much memory was required could be incorrect, leading to segfaults or other
2143     strange effects.
2145     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2146     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2147     there was a subsequent back reference to those brackets. This meant that, for
2148     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2149     possible to check for precisely this case. All we can do is abandon the
2150     optimization if .* occurs inside capturing brackets when there are any back
2151     references whatsoever. (See below for a better fix that came later.)
2153     26. The handling of the optimization for finding the first character of a
2154     non-anchored pattern, and for finding a character that is required later in the
2155     match were failing in some cases. This didn't break the matching; it just
2156     failed to optimize when it could. The way this is done has been re-implemented.
2158     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2160     28. Added a new feature that provides some of the functionality that Perl
2161     provides with (?{...}). The facility is termed a "callout". The way it is done
2162     in PCRE is for the caller to provide an optional function, by setting
2163     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2164     global variable. By default it is unset, which disables all calling out. To get
2165     the function called, the regex must include (?C) at appropriate points. This
2166     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2167     This provides a means of identifying different callout points. When PCRE
2168     reaches such a point in the regex, if pcre_callout has been set, the external
2169     function is called. It is provided with data in a structure called
2170     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2171     matching continues; if it returns a non-zero value, the match at the current
2172     point fails. However, backtracking will occur if possible. [This was changed
2173     later and other features added - see item 49 below.]
2175     29. pcretest is upgraded to test the callout functionality. It provides a
2176     callout function that displays information. By default, it shows the start of
2177     the match and the current position in the text. There are some new data escapes
2178     to vary what happens:
2180     \C+ in addition, show current contents of captured substrings
2181     \C- do not supply a callout function
2182     \C!n return 1 when callout number n is reached
2183     \C!n!m return 1 when callout number n is reached for the mth time
2185     30. If pcregrep was called with the -l option and just a single file name, it
2186     output "<stdin>" if a match was found, instead of the file name.
2188     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2189     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2190     pcre_exec(). This saves a malloc/free per call. The default value of
2191     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2192     when configuring.
2194     32. The default maximum size of a compiled pattern is 64K. There have been a
2195     few cases of people hitting this limit. The code now uses macros to handle the
2196     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2197     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2198     configuring. Tests 2 and 5 work only with 2-byte links because they output
2199     debugging information about compiled patterns.
2201     33. Internal code re-arrangements:
2203     (a) Moved the debugging function for printing out a compiled regex into
2204     its own source file (printint.c) and used #include to pull it into
2205     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2206     separate copies.
2208     (b) Defined the list of op-code names for debugging as a macro in
2209     internal.h so that it is next to the definition of the opcodes.
2211     (c) Defined a table of op-code lengths for simpler skipping along compiled
2212     code. This is again a macro in internal.h so that it is next to the
2213     definition of the opcodes.
2215     34. Added support for recursive calls to individual subpatterns, along the
2216     lines of Robin Houston's patch (but implemented somewhat differently).
2218     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2219     allow it to read and process whole directories in Win32. This code was
2220     contributed by Lionel Fourquaux; it has not been tested by me.
2222     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2223     used to name a group. Names consist of alphanumerics and underscores, and must
2224     be unique. Back references use the syntax (?P=name) and recursive calls use
2225     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2226     numbers. The function pcre_fullinfo() can be used after compilation to extract
2227     a name/number map. There are three relevant calls:
2229     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2230     PCRE_INFO_NAMECOUNT yields the number of entries
2231     PCRE_INFO_NAMETABLE yields a pointer to the map.
2233     The map is a vector of fixed-size entries. The size of each entry depends on
2234     the length of the longest name used. The first two bytes of each entry are the
2235     group number, most significant byte first. There follows the corresponding
2236     name, zero terminated. The names are in alphabetical order.
2238     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2239     case instead of 255. Making it the same both with and without UTF-8 support
2240     means that the same test output works with both.
2242     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2243     calling malloc() with a zero argument.
2245     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2246     optimization. I've improved things by keeping a bitmap of backreferences with
2247     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2248     fact referenced, the optimization can be applied. It is unlikely that a
2249     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2250     the match to follow \n) will appear inside brackets with a number greater than
2251     31, but if it does, any back reference > 31 suppresses the optimization.
2253     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2254     of disabling numbered capturing parentheses. Any opening parenthesis that is
2255     not followed by ? behaves as if it were followed by ?: but named parentheses
2256     can still be used for capturing (and they will acquire numbers in the usual
2257     way).
2259     41. Redesigned the return codes from the match() function into yes/no/error so
2260     that errors can be passed back from deep inside the nested calls. A malloc
2261     failure while inside a recursive subpattern call now causes the
2262     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2264     42. It is now possible to set a limit on the number of times the match()
2265     function is called in a call to pcre_exec(). This facility makes it possible to
2266     limit the amount of recursion and backtracking, though not in a directly
2267     obvious way, because the match() function is used in a number of different
2268     circumstances. The count starts from zero for each position in the subject
2269     string (for non-anchored patterns). The default limit is, for compatibility, a
2270     large number, namely 10 000 000. You can change this in two ways:
2272     (a) When configuring PCRE before making, you can use --with-match-limit=n
2273     to set a default value for the compiled library.
2275     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2276     a different value is set. See 45 below.
2278     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2280     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2281     of things that can be changed at compile time. The first argument specifies
2282     what is wanted and the second points to where the information is to be placed.
2283     The current list of available information is:
2287     The output is an integer that is set to one if UTF-8 support is available;
2288     otherwise it is set to zero.
2292     The output is an integer that it set to the value of the code that is used for
2293     newline. It is either LF (10) or CR (13).
2297     The output is an integer that contains the number of bytes used for internal
2298     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2302     The output is an integer that contains the threshold above which the POSIX
2303     interface uses malloc() for output vectors. See item 31 above.
2307     The output is an unsigned integer that contains the default limit of the number
2308     of match() calls in a pcre_exec() execution. See 42 above.
2310     44. pcretest has been upgraded by the addition of the -C option. This causes it
2311     to extract all the available output from the new pcre_config() function, and to
2312     output it. The program then exits immediately.
2314     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2315     order to support additional features. One way would have been to define
2316     pcre_exec2() (for example) with extra arguments, but this would not have been
2317     extensible, and would also have required all calls to the original function to
2318     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2319     is used for passing in "extra" data from pcre_study().
2321     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2322     contains the following fields:
2324     flags a bitmap indicating which of the following fields are set
2325     study_data opaque data from pcre_study()
2326     match_limit a way of specifying a limit on match() calls for a specific
2327     call to pcre_exec()
2328     callout_data data for callouts (see 49 below)
2330     The flag bits are also defined in pcre.h, and are
2336     The pcre_study() function now returns one of these new pcre_extra blocks, with
2337     the actual study data pointed to by the study_data field, and the
2338     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2339     before. That is, this change is entirely upwards-compatible and requires no
2340     change to existing code.
2342     If you want to pass in additional data to pcre_exec(), you can either place it
2343     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2344     block.
2346     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2347     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2348     times with different match limits, until it finds the minimum value needed for
2349     pcre_exec() to complete. The value is then output. This can be instructive; for
2350     most simple matches the number is quite small, but for pathological cases it
2351     gets very large very quickly.
2353     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2354     returns the size of the data block pointed to by the study_data field in a
2355     pcre_extra block, that is, the value that was passed as the argument to
2356     pcre_malloc() when PCRE was getting memory in which to place the information
2357     created by pcre_study(). The fourth argument should point to a size_t variable.
2358     pcretest has been extended so that this information is shown after a successful
2359     pcre_study() call when information about the compiled regex is being displayed.
2361     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2362     because what follows is always an absolute path. (Later: it turns out that this
2363     is more than cosmetic for MinGW, because it doesn't like empty path
2364     components.)
2366     49. Some changes have been made to the callout feature (see 28 above):
2368     (i) A callout function now has three choices for what it returns:
2370     0 => success, carry on matching
2371     > 0 => failure at this point, but backtrack if possible
2372     < 0 => serious error, return this value from pcre_exec()
2374     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2375     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2376     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2377     use by callout functions. It will never be used by PCRE itself.
2379     (ii) The pcre_extra structure (see 45 above) has a void * field called
2380     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2381     pcre_callout_block structure has a field of the same name. The contents of
2382     the field passed in the pcre_extra structure are passed to the callout
2383     function in the corresponding field in the callout block. This makes it
2384     easier to use the same callout-containing regex from multiple threads. For
2385     testing, the pcretest program has a new data escape
2387     \C*n pass the number n (may be negative) as callout_data
2389     If the callout function in pcretest receives a non-zero value as
2390     callout_data, it returns that value.
2392     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2393     there were some redundant $(CFLAGS) in commands that are now specified as
2394     $(LINK), which already includes $(CFLAGS).
2396     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2397     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2398     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2399     one-byte characters throughout. Note that case-insensitive matching applies
2400     only to characters whose values are less than 256. PCRE doesn't support the
2401     notion of cases for higher-valued characters.
2403     (i) A character class whose characters are all within 0-255 is handled as
2404     a bit map, and the map is inverted for negative classes. Previously, a
2405     character > 255 always failed to match such a class; however it should
2406     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2408     (ii) A negated character class with a single character < 255 is coded as
2409     "not this character" (OP_NOT). This wasn't working properly when the test
2410     character was multibyte, either singly or repeated.
2412     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2413     mode, for example: \x{100}{2,3}.
2415     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2416     singly or repeated) now correctly test multibyte characters. However,
2417     PCRE doesn't recognize any characters with values greater than 255 as
2418     digits, spaces, or word characters. Such characters always match \D, \S,
2419     and \W, and never match \d, \s, or \w.
2421     (v) Classes may now contain characters and character ranges with values
2422     greater than 255. For example: [ab\x{100}-\x{400}].
2424     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2425     PCRE in UTF-8 mode.
2427     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2428     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2429     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2430     value.)
2432     53. The single man page has become too large. I have therefore split it up into
2433     a number of separate man pages. These also give rise to individual HTML pages;
2434     these are now put in a separate directory, and there is an index.html page that
2435     lists them all. Some hyperlinking between the pages has been installed.
2437     54. Added convenience functions for handling named capturing parentheses.
2439     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2440     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2441     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2442     are faulted.
2444     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2445     calling configure. These values are used when compiling the dftables.c program
2446     which is run to generate the source of the default character tables. They
2447     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2448     you will need to set these values.
2450     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2453     Version 3.9 02-Jan-02
2454 nigel 61 ---------------------
2456     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2458     2. If --disable-static was given, the building process failed when trying to
2459     build pcretest and pcregrep. (For some reason it was using libtool to compile
2460     them, which is not right, as they aren't part of the library.)
2463 nigel 59 Version 3.8 18-Dec-01
2464     ---------------------
2466     1. The experimental UTF-8 code was completely screwed up. It was packing the
2467     bytes in the wrong order. How dumb can you get?
2470 nigel 57 Version 3.7 29-Oct-01
2471     ---------------------
2473     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2474     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2475     this didn't happen under Solaris 8, where I normally test things.
2477 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2478     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2479     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2480     this fix an hour or so after the initial 3.7 release.)
2481 nigel 57
2482 nigel 59
2483 nigel 55 Version 3.6 23-Oct-01
2484     ---------------------
2486     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2487     offsets passed as NULL with zero offset count.
2489     2. The config.guess and config.sub files had not been updated when I moved to
2490     the latest autoconf.
2493 nigel 53 Version 3.5 15-Aug-01
2494     ---------------------
2495 nigel 5
2496 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2497     had been forgotten.
2499     2. By using declared but undefined structures, we can avoid using "void"
2500     definitions in pcre.h while keeping the internal definitions of the structures
2501     private.
2503     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2504     user point of view, this means that both static and shared libraries are built
2505     by default, but this can be individually controlled. More of the work of
2506     handling this static/shared cases is now inside libtool instead of PCRE's make
2507     file.
2509     4. The pcretest utility is now installed along with pcregrep because it is
2510     useful for users (to test regexs) and by doing this, it automatically gets
2511     relinked by libtool. The documentation has been turned into a man page, so
2512     there are now .1, .txt, and .html versions in /doc.
2514     5. Upgrades to pcregrep:
2515     (i) Added long-form option names like gnu grep.
2516     (ii) Added --help to list all options with an explanatory phrase.
2517     (iii) Added -r, --recursive to recurse into sub-directories.
2518     (iv) Added -f, --file to read patterns from a file.
2520     6. pcre_exec() was referring to its "code" argument before testing that
2521     argument for NULL (and giving an error if it was NULL).
2523     7. Upgraded Makefile.in to allow for compiling in a different directory from
2524     the source directory.
2526     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2527     options bits, the pointer it was passed was to an int instead of to an unsigned
2528     long int. This mattered only on 64-bit systems.
2530     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2531     generated) instead of pcre.in, which it its source. Also made the same change
2532     in several of the .c files.
2534     10. A new release of gcc defines printf() as a macro, which broke pcretest
2535     because it had an ifdef in the middle of a string argument for printf(). Fixed
2536     by using separate calls to printf().
2538     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2539     script, to force use of CR or LF instead of \n in the source. On non-Unix
2540     systems, the value can be set in config.h.
2542     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2543     absolute limit. Changed the text of the error message to make this clear, and
2544     likewise updated the man page.
2546     13. The limit of 99 on the number of capturing subpatterns has been removed.
2547     The new limit is 65535, which I hope will not be a "real" limit.
2550 nigel 51 Version 3.4 22-Aug-00
2551     ---------------------
2553     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2555     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2558 nigel 49 Version 3.3 01-Aug-00
2559     ---------------------
2561     1. If an octal character was given, but the value was greater than \377, it
2562     was not getting masked to the least significant bits, as documented. This could
2563     lead to crashes in some systems.
2565     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2566     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2568     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2569     These just pass their arguments on to (pcre_free)(), but they are provided
2570     because some uses of PCRE bind it to non-C systems that can call its functions,
2571     but cannot call free() or pcre_free() directly.
2573     4. Add "make test" as a synonym for "make check". Corrected some comments in
2574     the Makefile.
2576     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2577     Makefile.
2579     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2580     command called pgrep for grepping around the active processes.
2582     7. Added the beginnings of support for UTF-8 character strings.
2584     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2585     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2586     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2587     out for the ar command.)
2590 nigel 47 Version 3.2 12-May-00
2591     ---------------------
2593     This is purely a bug fixing release.
2595     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2596     of ZA. This was just one example of several cases that could provoke this bug,
2597     which was introduced by change 9 of version 2.00. The code for breaking
2598     infinite loops after an iteration that matches an empty string was't working
2599     correctly.
2601     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2602     when matched against abbab (for example). After matching an empty string, it
2603     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2604     caused it to match further down the string than it should.
2606     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2607     was there because it doesn't seem to be needed, and it causes trouble on some
2608     systems, as it is not a Standard C header. It has been removed.
2610     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2611     were reported on the Macintosh. The changes were from
2613     while ((c = *(++ptr)) != 0 && c != '\n');
2614     to
2615     while ((c = *(++ptr)) != 0 && c != '\n') ;
2617     Totally extraordinary, but if that's what it takes...
2619     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2620     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2621     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2622     assumes the way PCRE uses memmove() (always moving upwards).
2624     6. PCRE is being used in one environment where strchr() is not available. There
2625     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2626     faster code anyway.
2629 nigel 45 Version 3.1 09-Feb-00
2630     ---------------------
2632     The only change in this release is the fixing of some bugs in Makefile.in for
2633     the "install" target:
2635     (1) It was failing to install pcreposix.h.
2637     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2640 nigel 43 Version 3.0 01-Feb-00
2641     ---------------------
2642 nigel 41
2643     1. Add support for the /+ modifier to perltest (to output $` like it does in
2644     pcretest).
2646     2. Add support for the /g modifier to perltest.
2648     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2649     matches null strings.
2651     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2652     pattern. Perl treats empty patterns specially - it reuses the most recent
2653     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2654     effect.
2656     5. The POSIX interface was broken in that it was just handing over the POSIX
2657     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2658     required a bigger vector, with some working space on the end. This means that
2659     the POSIX wrapper now has to get and free some memory, and copy the results.
2661 nigel 43 6. Added some simple autoconf support, placing the test data and the
2662     documentation in separate directories, re-organizing some of the
2663     information files, and making it build pcre-config (a GNU standard). Also added
2664     libtool support for building PCRE as a shared library, which is now the
2665     default.
2666 nigel 41
2667 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2668     09 are not valid octal constants. Single digits will be used for minor values
2669     less than 10.
2671     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2672     existing programs that set these in the POSIX interface can use PCRE without
2673     modification.
2675     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2676     return all that pcre_info() returns, plus additional data. The pcre_info()
2677     function is retained for compatibility, but is considered to be obsolete.
2679     10. Added experimental recursion feature (?R) to handle one common case that
2680     Perl 5.6 will be able to do with (?p{...}).
2682     11. Added support for POSIX character classes like [:alpha:], which Perl is
2683     adopting.
2686 nigel 39 Version 2.08 31-Aug-99
2687     ----------------------
2689     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2690     trying to match at the startoffset position, but instead was moving forward to
2691     the next newline as if a previous match had failed.
2693     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2694     and could get into a loop if a null string was matched other than at the start
2695     of the subject.
2697     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2698     be distinguished at compile time, and for completeness also added PCRE_DATE.
2700     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2701     in GnuWin32 environments.
2704 nigel 37 Version 2.07 29-Jul-99
2705     ----------------------
2707     1. The documentation is now supplied in plain text form and HTML as well as in
2708     the form of man page sources.
2710     2. C++ compilers don't like assigning (void *) values to other pointer types.
2711     In particular this affects malloc(). Although there is no problem in Standard
2712     C, I've put in casts to keep C++ compilers happy.
2714     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2715     should be (const char *).
2717     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2718     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2719     However, I haven't made this a standard facility. The documentation doesn't
2720     mention it, and the Makefile doesn't support it.
2722     5. The Makefile now contains an "install" target, with editable destinations at
2723     the top of the file. The pcretest program is not installed.
2725     6. pgrep -V now gives the PCRE version number and date.
2727     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2728     causing the entire string to be ignored, instead of just the last character.
2730     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2731     non-matching string, it can take a very, very long time, even for strings of
2732     quite modest length, because of the nested recursion. PCRE now does better in
2733     some of these cases. It does this by remembering the last required literal
2734     character in the pattern, and pre-searching the subject to ensure it is present
2735     before running the real match. In other words, it applies a heuristic to detect
2736     some types of certain failure quickly, and in the above example, if presented
2737     with a string that has no trailing " it gives "no match" very quickly.
2739     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2740     other alternatives are tried instead.
2743 nigel 35 Version 2.06 09-Jun-99
2744     ----------------------
2746     1. Change pcretest's output for amount of store used to show just the code
2747     space, because the remainder (the data block) varies in size between 32-bit and
2748     64-bit systems.
2750     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2751     start matching at. This allows lookbehinds to work when searching for multiple
2752     occurrences in a string.
2754     3. Added additional options to pcretest for testing multiple occurrences:
2756     /+ outputs the rest of the string that follows a match
2757     /g loops for multiple occurrences, using the new startoffset argument
2758     /G loops for multiple occurrences by passing an incremented pointer
2760     4. PCRE wasn't doing the "first character" optimization for patterns starting
2761     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2762     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2763     the letter 'x'. On long subject strings, this gives a significant speed-up.
2766 nigel 33 Version 2.05 21-Apr-99
2767     ----------------------
2769     1. Changed the type of magic_number from int to long int so that it works
2770     properly on 16-bit systems.
2772     2. Fixed a bug which caused patterns starting with .* not to work correctly
2773     when the subject string contained newline characters. PCRE was assuming
2774     anchoring for such patterns in all cases, which is not correct because .* will
2775     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2776     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2777     must be retried after every newline in the subject.
2780 nigel 31 Version 2.04 18-Feb-99
2781     ----------------------
2783     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2784     computation of the store needed to hold the pattern was incorrect (too large).
2785     If such patterns were nested a few deep, this could multiply and become a real
2786     problem.
2788     2. Added /M option to pcretest to show the memory requirement of a specific
2789     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2791     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2792     compiled in such a way that the backtracking after subsequent failure was
2793     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2794     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2797 nigel 29 Version 2.03 02-Feb-99
2798     ----------------------
2800     1. Fixed typo and small mistake in man page.
2802 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2803     LICENCE file containing the conditions.
2804 nigel 29
2805     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2806     Perl, that is the internal \ allows the delimiter to be included in the
2807     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2808     the final delimiter, add \ to the end of the pattern (to test the error).
2810     4. Added the convenience functions for extracting substrings after a successful
2811     match. Updated pcretest to make it able to test these functions.
2814 nigel 27 Version 2.02 14-Jan-99
2815     ----------------------
2817     1. Initialized the working variables associated with each extraction so that
2818     their saving and restoring doesn't refer to uninitialized store.
2820     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2821     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2822     fix the problem.
2824     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2825     calls, and wasn't printing the correct value for compiling calls. Increased the
2826     default value of LOOPREPEAT, and the number of significant figures in the
2827     times.
2829     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2831     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2832     a building problem on Windows NT with a FAT file system.
2835 nigel 25 Version 2.01 21-Oct-98
2836     ----------------------
2838     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2839     to character tables built by pcre_maketables() in the current locale. If NULL
2840     is passed, the default tables are used.
2843 nigel 23 Version 2.00 24-Sep-98
2844 nigel 21 ----------------------
2846 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2847     it any more.
2849     2. Allow quantification of (?>) groups, and make it work correctly.
2851     3. The first character computation wasn't working for (?>) groups.
2853     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2854     end of the subject) and add 5.005's \z, which really does match only at the
2855     very end of the subject.
2857     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2859     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2860     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2861     localized options. All options to pcre_study() were also removed.
2863     7. Add other new features from 5.005:
2865     $(?<= positive lookbehind
2866     $(?<! negative lookbehind
2867     (?imsx-imsx) added the unsetting capability
2868     such a setting is global if at outer level; local otherwise
2869     (?imsx-imsx:) non-capturing groups with option setting
2870     (?(cond)re|re) conditional pattern matching
2872     A backreference to itself in a repeated group matches the previous
2873     captured string.
2875     8. General tidying up of studying (both automatic and via "study")
2876     consequential on the addition of new assertions.
2878     9. As in 5.005, unlimited repeated groups that could match an empty substring
2879     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2880     runtime if any iteration does actually match an empty substring.
2882     10. Include the RunTest script in the distribution.
2884     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2885     discrepancies, some of which were old and were also with respect to 5.004. They
2886     have now been fixed.
2889     Version 1.09 28-Apr-98
2890     ----------------------
2892 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2893     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2894     program crashes, or just wrong answers. This did not apply to negated classes
2895     containing more than one character, or to minima other than one.
2898 nigel 19 Version 1.08 27-Mar-98
2899     ----------------------
2901     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2903     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2904     latter must appear before anything that relies on it in the pattern.
2907 nigel 17 Version 1.07 16-Feb-98
2908     ----------------------
2910     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2911     repeat of a potentially empty string).
2914 nigel 15 Version 1.06 23-Jan-98
2915     ----------------------
2917     1. Added Markus Oberhumer's little patches for C++.
2919     2. Literal strings longer than 255 characters were broken.
2922 nigel 13 Version 1.05 23-Dec-97
2923     ----------------------
2925     1. Negated character classes containing more than one character were failing if
2926     PCRE_CASELESS was set at run time.
2929 nigel 11 Version 1.04 19-Dec-97
2930     ----------------------
2932     1. Corrected the man page, where some "const" qualifiers had been omitted.
2934     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2935     input syntax.
2937     3. Fixed memory leak which occurred when a regex with back references was
2938     matched with an offsets vector that wasn't big enough. The temporary memory
2939     that is used in this case wasn't being freed if the match failed.
2941     4. Tidied pcretest to ensure it frees memory that it gets.
2943     5. Temporary memory was being obtained in the case where the passed offsets
2944     vector was exactly big enough.
2946     6. Corrected definition of offsetof() from change 5 below.
2948     7. I had screwed up change 6 below and broken the rules for the use of
2949     setjmp(). Now fixed.
2952 nigel 9 Version 1.03 18-Dec-97
2953     ----------------------
2955     1. A erroneous regex with a missing opening parenthesis was correctly
2956     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2957     on some systems.
2959     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2960     it was reported that one broken compiler failed on the former because "code" is
2961     also an independent variable.
2963     3. The erroneous regex a[]b caused an array overrun reference.
2965     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2966     fail on data ending with that character. (It was going on too far, and checking
2967     the next character, typically a binary zero.) This was specific to the
2968     optimized code for single-character negative classes.
2970     5. Added a contributed patch from the TIN world which does the following:
2972     + Add an undef for memmove, in case the the system defines a macro for it.
2974     + Add a definition of offsetof(), in case there isn't one. (I don't know
2975     the reason behind this - offsetof() is part of the ANSI standard - but
2976     it does no harm).
2978     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2979     most of the places where whitespace preceded '#'. I have given up and
2980     allowed the remaining 2 cases to be at the margin.
2982     + Rename some variables in pcre to eliminate shadowing. This seems very
2983     pedantic, but does no harm, of course.
2985     6. Moved the call to setjmp() into its own function, to get rid of warnings
2986     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2988     7. Constructs such as \d{8,} were compiling into the equivalent of
2989 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2990 nigel 9 outcome, but in this particular case used more store than had been allocated,
2991     which caused the bug to be discovered because it threw up an internal error.
2993     8. The debugging code in both pcre and pcretest for outputting the compiled
2994     form of a regex was going wrong in the case of back references followed by
2995     curly-bracketed repeats.
2998 nigel 7 Version 1.02 12-Dec-97
2999     ----------------------
3001     1. Typos in pcre.3 and comments in the source fixed.
3003     2. Applied a contributed patch to get rid of places where it used to remove
3004     'const' from variables, and fixed some signed/unsigned and uninitialized
3005     variable warnings.
3007     3. Added the "runtest" target to Makefile.
3009     4. Set default compiler flag to -O2 rather than just -O.
3012 nigel 5 Version 1.01 19-Nov-97
3013     ----------------------
3015     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3016     like /([ab]*)*/, that is, for classes with more than one character in them.
3018     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3019     as /((?>a*))*/ (a PCRE_EXTRA facility).
3022     Version 1.00 18-Nov-97
3023     ----------------------
3025     1. Added compile-time macros to support systems such as SunOS4 which don't have
3026     memmove() or strerror() but have other things that can be used instead.
3028     2. Arranged that "make clean" removes the executables.
3031 nigel 3 Version 0.99 27-Oct-97
3032     ----------------------
3034     1. Fixed bug in code for optimizing classes with only one character. It was
3035     initializing a 32-byte map regardless, which could cause it to run off the end
3036     of the memory it had got.
3038     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3041     Version 0.98 22-Oct-97
3042     ----------------------
3044     1. Fixed bug in code for handling temporary memory usage when there are more
3045     back references than supplied space in the ovector. This could cause segfaults.
3048     Version 0.97 21-Oct-97
3049     ----------------------
3051     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3053     2. Optimized negated single characters not to use a bit map.
3055     3. Brought error texts together as macro definitions; clarified some of them;
3056     fixed one that was wrong - it said "range out of order" when it meant "invalid
3057     escape sequence".
3059     4. Changed some char * arguments to const char *.
3061     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3063     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3064     pcretest.
3067     Version 0.96 16-Oct-97
3068     ----------------------
3070     1. Added a simple "pgrep" utility to the distribution.
3072     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3073     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3074     where "ddd" means "one or more decimal digits".
3076     3. Fixed serious bug. If a pattern had a back reference, but the call to
3077     pcre_exec() didn't supply a large enough ovector to record the related
3078     identifying subpattern, the match always failed. PCRE now remembers the number
3079     of the largest back reference, and gets some temporary memory in which to save
3080     the offsets during matching if necessary, in order to ensure that
3081     backreferences always work.
3083     4. Increased the compatibility with Perl in a number of ways:
3085     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3086     to request this handling. The option can be set at compile or exec time.
3088     (b) $ matches before a terminating newline by default; an option
3089     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3090     mode). The option can be set at compile or exec time.
3092     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3093     the same as Perl's. If the decimal number it represents is less than 10
3094     or there aren't that many previous left capturing parentheses, an octal
3095     escape is read. Inside a character class, it's always an octal escape,
3096     even if it is a single digit.
3098     (d) An escaped but undefined alphabetic character is taken as a literal,
3099     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3100     escapes.
3102     (e) {0} is now permitted. (The previous item is removed from the compiled
3103     pattern).
3105     5. Changed all the names of code files so that the basic parts are no longer
3106     than 10 characters, and abolished the teeny "globals.c" file.
3108     6. Changed the handling of character classes; they are now done with a 32-byte
3109     bit map always.
3111     7. Added the -d and /D options to pcretest to make it possible to look at the
3112     internals of compilation without having to recompile pcre.
3115     Version 0.95 23-Sep-97
3116     ----------------------
3118     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3119     \x20 at the start of a run of normal characters. These were being treated as
3120     real characters, instead of the source characters being re-checked.
3123     Version 0.94 18-Sep-97
3124     ----------------------
3126     1. The functions are now thread-safe, with the caveat that the global variables
3127     containing pointers to malloc() and free() or alternative functions are the
3128     same for all threads.
3130     2. Get pcre_study() to generate a bitmap of initial characters for non-
3131     anchored patterns when this is possible, and use it if passed to pcre_exec().
3134     Version 0.93 15-Sep-97
3135     ----------------------
3137     1. /(b)|(:+)/ was computing an incorrect first character.
3139     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3140     but not actually doing anything yet.
3142     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3143     as Perl does (e.g. [-az] or [az-]).
3145     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3146     all possible positions.
3148     5. Split up into different modules to avoid including unneeded functions in a
3149     compiled binary. However, compile and exec are still in one module. The "study"
3150     function is split off.
3152     6. The character tables are now in a separate module whose source is generated
3153     by an auxiliary program - but can then be edited by hand if required. There are
3154     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3155     toupper() in the code.
3157     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3158     make them global. Abolish the function for setting them, as the caller can now
3159     set them directly.
3162     Version 0.92 11-Sep-97
3163     ----------------------
3165     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3166     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3168     2. Caseless matching was not working in character classes if the characters in
3169     the pattern were in upper case.
3171     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3173     4. Make PCRE_ANCHORED public and accept as a compile option.
3175     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3176     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3177     pass them.
3179     6. Give an error if bad option bits passed at compile or run time.
3181     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3182     pcretest to cause it to pass that flag.
3184     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3185     options, and the first character, if set.
3187     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3190     Version 0.91 10-Sep-97
3191     ----------------------
3193     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3194     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3196     2. PCRE was looping on encountering an indefinitely repeated back reference to
3197     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3198     Perl does - treats the match as successful.
3200     ****


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