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Revision 307 - (hide annotations) (download)
Sun Jan 20 20:36:45 2008 UTC (6 years, 7 months ago) by ph10
File size: 149597 byte(s)
Add Ron Aaron's Makefile patch (experimentally).

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 302 Version 7.6 19-Jan-08
5 ph10 300 ---------------------
6    
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    
11     2. Patch to cut out the "long long" test in pcrecpp_unittest when
12     HAVE_LONG_LONG is not defined.
13 ph10 303
14     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    
17     - Fixed PH's badly added libz and libbz2 support.
18     - Fixed a problem with static linking.
19     - Added pcredemo.
20     - Fixed dftables problem and added an option.
21     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
22     HAVE_LONG_LONG.
23     - Added readline support for pcretest.
24     - Added an listing of the option settings after cmake has run.
25 ph10 307
26     4. A user submitted a patch to Makefile that makes it easy to created a dll
27     under mingw. I added stuff to Makefile.am that cause it to include this
28     special target, without affecting anything else.
29 ph10 300
30    
31 ph10 298 Version 7.5 10-Jan-08
32 ph10 263 ---------------------
33    
34     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
35     values in parens when parsing an RE using the C++ wrapper."
36 ph10 286
37 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
38     Characters greater than 255 were excluded from the class instead of being
39     included.
40 ph10 286
41     3. The same bug as (2) above applied to negated POSIX classes such as
42 ph10 265 [:^space:].
43 ph10 286
44 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
45     defined or documented. It seems to have been a typo for PCRE_STATIC, so
46 ph10 286 I have changed it.
47    
48 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
49 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
50     first named subpattern whose name started with "a" (in other words, the
51 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
52     expected" is now given for (?&) (a zero-length name), and this patch also
53     makes it give the same error for \k'' (previously it complained that that
54     was a reference to a non-existent subpattern).
55 ph10 286
56 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
57 ph10 286 this is right because (?- can be followed by option settings as well as by
58 ph10 269 digits. I have, however, made the messages clearer.
59 ph10 286
60 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
61     than the number used in the conditional) now cause a compile-time error.
62     This is actually not compatible with Perl, which accepts such patterns, but
63     treats the conditional as always being FALSE (as PCRE used to), but it
64     seems to me that giving a diagnostic is better.
65 ph10 286
66 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
67 ph10 275 and messages.
68 ph10 286
69     9. Fix two occurrences of "backslash" in comments that should have been
70     "backspace".
71    
72     10. Remove two redundant lines of code that can never be obeyed (their function
73     was moved elsewhere).
74    
75     11. The program that makes PCRE's Unicode character property table had a bug
76     which caused it to generate incorrect table entries for sequences of
77 ph10 277 characters that have the same character type, but are in different scripts.
78 ph10 286 It amalgamated them into a single range, with the script of the first of
79 ph10 277 them. In other words, some characters were in the wrong script. There were
80     thirteen such cases, affecting characters in the following ranges:
81 ph10 286
82 ph10 277 U+002b0 - U+002c1
83     U+0060c - U+0060d
84 ph10 286 U+0061e - U+00612
85 ph10 277 U+0064b - U+0065e
86     U+0074d - U+0076d
87     U+01800 - U+01805
88     U+01d00 - U+01d77
89     U+01d9b - U+01dbf
90     U+0200b - U+0200f
91     U+030fc - U+030fe
92     U+03260 - U+0327f
93     U+0fb46 - U+0fbb1
94     U+10450 - U+1049d
95 ph10 286
96 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
97     compatible with GNU grep in that, if there was more than one match in a
98     line, it showed only the first of them. It now behaves in the same way as
99     GNU grep.
100 ph10 286
101     13. If the -o and -v options were combined for pcregrep, it printed a blank
102     line for every non-matching line. GNU grep prints nothing, and pcregrep now
103     does the same. The return code can be used to tell if there were any
104     non-matching lines.
105    
106 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
107    
108     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
109 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
110 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
111     and both kinds of lookbehind were skipped).
112    
113 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
114 ph10 284 inclusion of <windows.h> to before rather than after the definition of
115     INVALID_FILE_ATTRIBUTES (patch from David Byron).
116 ph10 263
117 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
118 ph10 286 character property caused pcre_compile() to compile bad code, which led at
119     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
120     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
121     caused the error; without that there was no problem.
122 ph10 263
123 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
124 ph10 286
125 ph10 289 19. Added --enable-pcretest-libreadline.
126 ph10 286
127 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
128 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
129 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
130     later patch that removed the other one (the right fix) and added unit tests
131     that check the return values (which was not done before).
132 ph10 292
133 ph10 291 21. Several CMake things:
134 ph10 287
135 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
136 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
137 ph10 288
138 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
139     linked with the newly-built libraries, not previously installed ones.
140 ph10 291
141 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
142 ph10 298
143     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
144     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
145     UTF-8 newline character). The key issue is that the pattern starts .*;
146     this means that the match must be either at the beginning, or after a
147     newline. The bug was in the code for advancing after a failed match and
148     checking that the new position followed a newline. It was not taking
149 ph10 294 account of UTF-8 characters correctly.
150 ph10 298
151     23. PCRE was behaving differently from Perl in the way it recognized POSIX
152     character classes. PCRE was not treating the sequence [:...:] as a
153     character class unless the ... were all letters. Perl, however, seems to
154     allow any characters between [: and :], though of course it rejects as
155     unknown any "names" that contain non-letters, because all the known class
156     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
157     for example, whereas PCRE did not - it did not recognize a POSIX character
158     class. This seemed a bit dangerous, so the code has been changed to be
159     closer to Perl. The behaviour is not identical to Perl, because PCRE will
160     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
161     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
162     Perl does, and where it didn't before.
163    
164 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
165     Windows environments %n is disabled by default.
166 ph10 292
167    
168 ph10 260 Version 7.4 21-Sep-07
169 ph10 230 ---------------------
170    
171     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
172 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
173     LF". That isn't really right - the whole point of the change was to try to
174     help when there was an actual mention of one of the two characters. So now
175     the change happens only if \r or \n (or a literal CR or LF) character is
176 ph10 230 encountered.
177 ph10 231
178     2. The 32-bit options word was also used for 6 internal flags, but the numbers
179     of both had grown to the point where there were only 3 bits left.
180     Fortunately, there was spare space in the data structure, and so I have
181     moved the internal flags into a new 16-bit field to free up more option
182 ph10 230 bits.
183 ph10 231
184     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
185     but did not set the internal JCHANGED flag - either of these is enough to
186     control the way the "get" function works - but the PCRE_INFO_JCHANGED
187     facility is supposed to tell if (?J) was ever used, so now (?J) at the
188 ph10 230 start sets both bits.
189    
190 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
191     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
192 ph10 230
193 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
194    
195     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
196 ph10 233 compatibility, even though it is no longer used.
197 ph10 243
198     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
199 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
200 ph10 259 windows.h file is present (where different names are used). [This was
201 ph10 257 reversed later after testing - see 16 below.]
202 ph10 243
203     8. Changed all #include <config.h> to #include "config.h". There were also
204 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
205 ph10 243
206 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
207 ph10 243 sequence off the lines that it output.
208    
209     10. It was pointed out to me that arrays of string pointers cause lots of
210     relocations when a shared library is dynamically loaded. A technique of
211     using a single long string with a table of offsets can drastically reduce
212     these. I have refactored PCRE in four places to do this. The result is
213 ph10 240 dramatic:
214 ph10 243
215 ph10 240 Originally: 290
216     After changing UCP table: 187
217 ph10 243 After changing error message table: 43
218 ph10 240 After changing table of "verbs" 36
219     After changing table of Posix names 22
220 ph10 243
221 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
222 ph10 247
223 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
224 ph10 247 unicode-properties was also set.
225    
226 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
227 ph10 231
228 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
229     checked only for CRLF.
230 ph10 233
231 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
232    
233 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
234 ph10 253
235 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
236 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
237     entirely. This removes changes made in 7 above.
238 ph10 256
239 ph10 261 17. The CMake files have been updated, and there is now more information about
240     building with CMake in the NON-UNIX-USE document.
241 ph10 257
242 ph10 261
243 ph10 228 Version 7.3 28-Aug-07
244 ph10 157 ---------------------
245    
246 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
247     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
248     brackets there is not right, since it causes compilers to look for an
249     installed pcre.h, not the version that is in the source that is being
250     compiled (which of course may be different). I have changed it back to:
251 ph10 197
252 ph10 189 #include "pcre.h"
253 ph10 197
254     I have a vague recollection that the change was concerned with compiling in
255     different directories, but in the new build system, that is taken care of
256     by the VPATH setting the Makefile.
257    
258 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
259     when the subject happened to end in the byte 0x85 (e.g. if the last
260     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
261     characters but of course it shouldn't be taken as a newline when it is part
262     of another character. The bug was that, for an unlimited repeat of . in
263     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
264     characters when looking for a newline.
265 ph10 197
266     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
267    
268     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
269     in debug output.
270    
271 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
272     long printing in the pcrecpp unittest when running under MinGW.
273 ph10 189
274 ph10 197 6. ESC_K was left out of the EBCDIC table.
275 ph10 189
276 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
277     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
278     limit also applies to "virtual nesting" when a pattern is recursive, and in
279     this case 1000 isn't so big. I have been able to remove this limit at the
280     expense of backing off one optimization in certain circumstances. Normally,
281     when pcre_exec() would call its internal match() function recursively and
282     immediately return the result unconditionally, it uses a "tail recursion"
283     feature to save stack. However, when a subpattern that can match an empty
284     string has an unlimited repetition quantifier, it no longer makes this
285     optimization. That gives it a stack frame in which to save the data for
286     checking that an empty string has been matched. Previously this was taken
287     from the 1000-entry workspace that had been reserved. So now there is no
288     explicit limit, but more stack is used.
289 ph10 189
290 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
291     syntax that is required for Windows, and which was going wrong for the
292     pcreposix and pcrecpp parts of the library. These were overlooked when this
293     problem was solved for the main library.
294 ph10 197
295 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
296     the size of patterns that contain repeated groups with explicit upper
297     limits. As the maximum quantifier is 65535, the maximum group length was
298     set at 30,000 so that the product of these two numbers did not overflow a
299     32-bit integer. However, it turns out that people want to use groups that
300     are longer than 30,000 bytes (though not repeat them that many times).
301     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
302     made it possible to implement the integer overflow checks in a much more
303     dynamic way, which I have now done. The artificial limitation on group
304     length has been removed - we now have only the limit on the total length of
305     the compiled pattern, which depends on the LINK_SIZE setting.
306 ph10 208
307     10. Fixed a bug in the documentation for get/copy named substring when
308     duplicate names are permitted. If none of the named substrings are set, the
309     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
310     empty string.
311    
312     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
313     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
314     because the ] is interpreted as the first data character and the
315     terminating ] is not found. PCRE has been made compatible with Perl in this
316     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
317     cause memory overwriting.
318    
319 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
320     string has been matched (to stop an infinite loop). It was not recognizing
321 ph10 208 a conditional subpattern that could match an empty string if that
322 ph10 206 subpattern was within another subpattern. For example, it looped when
323 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
324 ph10 206 condition was not nested. This bug has been fixed.
325 ph10 208
326 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
327     past the start of the subject in the presence of bytes with the top bit
328     set, for example "\x8aBCD".
329 ph10 211
330 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
331     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
332 ph10 200
333 ph10 211 14. Optimized (?!) to (*FAIL).
334 ph10 202
335 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
336     This restricts code points to be within the range 0 to 0x10FFFF, excluding
337     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
338     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
339     does: it's just the validity check that is more restrictive.
340 ph10 220
341     16. Inserted checks for integer overflows during escape sequence (backslash)
342     processing, and also fixed erroneous offset values for syntax errors during
343     backslash processing.
344    
345 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
346 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
347    
348 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
349     caused an overrun.
350 ph10 220
351     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
352     something other than just ASCII characters) inside a group that had an
353     unlimited repeat caused a loop at compile time (while checking to see
354     whether the group could match an empty string).
355    
356 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
357     [\P{Any}] did so. (Error in the code for printing property names.)
358 ph10 210
359 ph10 220 21. An orphan \E inside a character class could cause a crash.
360    
361     22. A repeated capturing bracket such as (A)? could cause a wild memory
362 ph10 218 reference during compilation.
363 ph10 220
364     23. There are several functions in pcre_compile() that scan along a compiled
365     expression for various reasons (e.g. to see if it's fixed length for look
366 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
367 ph10 220 present in the pattern. These operators have additional parameters compared
368     with \d, etc, and these were not being taken into account when moving along
369 ph10 218 the compiled data. Specifically:
370 ph10 220
371     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
372     length.
373    
374     (b) An item such as \pL+ within a repeated group could cause crashes or
375 ph10 218 loops.
376 ph10 220
377 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
378 ph10 220 "reference to non-existent subpattern" error.
379    
380 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
381    
382 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
383 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
384 ph10 211
385 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
386 ph10 218
387 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
388 ph10 223 character were causing crashes (broken optimization).
389 ph10 227
390 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
391 ph10 227 \p or \P) caused a compile-time loop.
392    
393 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
394     break. For example, the unstudied pattern [\r\n]A does not match the string
395     "\r\nA" because change 7.0/46 below moves the current point on by two
396     characters after failing to match at the start. However, the pattern \nA
397 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
398     the same is true. There doesn't seem any very clean way out of this, but
399     what I have chosen to do makes the common cases work: PCRE now takes note
400     of whether there can be an explicit match for \r or \n anywhere in the
401     pattern, and if so, 7.0/46 no longer applies. As part of this change,
402     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
403     pattern has explicit CR or LF references.
404 ph10 222
405 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
406 ph10 223
407 ph10 227
408 ph10 189 Version 7.2 19-Jun-07
409     ---------------------
410    
411 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
412     which is apparently normally available under Windows.
413 ph10 159
414     2. Re-jig the pcregrep tests with different newline settings in an attempt
415     to make them independent of the local environment's newline setting.
416 ph10 157
417 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
418 ph10 165
419 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
420     was not 2, because the output contained actual offsets. The recent new
421 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
422     usable with all link sizes.
423    
424 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
425     stack recursion. This gives a massive performance boost under BSD, but just
426 ph10 165 a small improvement under Linux. However, it saves one field in the frame
427 ph10 164 in all cases.
428 ph10 172
429 ph10 166 6. Added more features from the forthcoming Perl 5.10:
430 ph10 172
431 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
432     recursion call. It refers to the nth most recently opened parentheses.
433 ph10 172
434 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
435 ph10 172 to be opened parentheses.
436    
437     (c) Conditions that refer to capturing parentheses can be specified
438 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
439 ph10 172
440 ph10 168 (d) \K resets the start of the current match so that everything before
441 ph10 172 is not part of it.
442    
443 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
444 ph10 172
445 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
446 ph10 172 reference syntax.
447 ph10 182
448 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
449 ph10 182 alternative starts with the same number.
450 ph10 172
451 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
452    
453 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
454     PCRE_INFO_JCHANGED.
455    
456     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
457     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
458 ph10 170 for detecting groups that can match an empty string.
459 ph10 159
460 ph10 172 9. A pattern with a very large number of alternatives (more than several
461     hundred) was running out of internal workspace during the pre-compile
462     phase, where pcre_compile() figures out how much memory will be needed. A
463     bit of new cunning has reduced the workspace needed for groups with
464     alternatives. The 1000-alternative test pattern now uses 12 bytes of
465     workspace instead of running out of the 4096 that are available.
466 ph10 182
467 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
468 ph10 172
469 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
470     The report of the bug said:
471 ph10 182
472 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
473     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
474 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
475 ph10 185
476 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
477 ph10 185 it matched the wrong number of bytes.
478 ph10 172
479 ph10 179
480 ph10 155 Version 7.1 24-Apr-07
481 ph10 98 ---------------------
482    
483 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
484 ph10 122 that is more "standard", making use of automake and other Autotools. There
485 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
486     on this.
487 ph10 111
488     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
489     for recursive directory scanning broke on some systems because the files
490     are not scanned in any specific order and on different systems the order
491     was different. A call to "sort" has been inserted into RunGrepTest for the
492     approprate test as a short-term fix. In the longer term there may be an
493 ph10 100 alternative.
494 ph10 111
495 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
496 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
497     people do their own conversions for various reasons). The problems
498     concerned the use of low-level troff macros .br and .in. I have therefore
499     removed all such uses from the man pages (some were redundant, some could
500 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
501     HTML has been updated to handle .nf/.fi and to complain if it encounters
502     .br or .in.
503 ph10 111
504 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
505 ph10 123 arranged for config.h to be included in the distribution, with the name
506 ph10 111 config.h.generic, for the benefit of those who have to compile without
507     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
508    
509     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
510     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
511 ph10 127 makevp.bat for the current PCRE, using the additional files
512 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
513 ph10 111
514     6. A Windows user reported a minor discrepancy with test 2, which turned out
515     to be caused by a trailing space on an input line that had got lost in his
516 ph10 102 copy. The trailing space was an accident, so I've just removed it.
517 ph10 111
518 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
519 ph10 111 that is needed.
520    
521 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
522     as "const" (a) because they are and (b) because it helps the PHP
523     maintainers who have recently made a script to detect big data structures
524 ph10 111 in the php code that should be moved to the .rodata section. I remembered
525     to update Builducptable as well, so it won't revert if ucptable.h is ever
526 ph10 105 re-created.
527 ph10 111
528     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
529 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
530 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
531     support is not required. This saves 1.5-2K of code, which is important in
532 ph10 107 some applications.
533 ph10 111
534 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
535 ph10 111 so as not to refer to the tables, even though these functions will never be
536     called when UTF-8 support is disabled. Otherwise there are problems with a
537     shared library.
538    
539 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
540    
541     (a) It was defining its arguments as char * instead of void *.
542    
543 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
544     a long time ago when I wrote it, but is no longer the case.
545    
546 ph10 118 The emulated memove() is provided for those environments that have neither
547 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
548 ph10 118 is clearly not the case, as these two bugs were recently reported.
549 ph10 123
550 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
551 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
552     pages, and it removes trailing spaces from listed files. It also creates
553     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
554     case, it wraps all the #defines with #ifndefs. This script should be run
555 ph10 111 before "make dist".
556 ph10 123
557 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
558     with Unicode property support.
559 ph10 123
560     (a) For a maximizing quantifier, if the two different cases of the
561     character were of different lengths in their UTF-8 codings (there are
562     some cases like this - I found 11), and the matching function had to
563 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
564     were both the same length.
565 ph10 123
566     (b) When PCRE was configured to use the heap rather than the stack for
567     recursion during matching, it was not correctly preserving the data for
568     the other case of a UTF-8 character when checking ahead for a match
569     while processing a minimizing repeat. If the check also involved
570 ph10 115 matching a wide character, but failed, corruption could cause an
571     erroneous result when trying to check for a repeat of the original
572     character.
573 ph10 123
574 ph10 116 13. Some tidying changes to the testing mechanism:
575 ph10 98
576 ph10 116 (a) The RunTest script now detects the internal link size and whether there
577     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
578 ph10 123 values substituted by "configure". (The RunGrepTest script already did
579     this for UTF-8.) The configure.ac script no longer substitutes the
580     relevant variables.
581    
582 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
583     with length and offset values. This means that the output is different
584     for different internal link sizes. Test 2 is skipped for link sizes
585     other than 2 because of this, bypassing the problem. Unfortunately,
586     there was also a test in test 3 (the locale tests) that used /B and
587 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
588     I have added a new /Z option to pcretest that replaces the length and
589     offset values with spaces. This is now used to make test 3 independent
590 ph10 122 of link size. (Test 2 will be tidied up later.)
591 ph10 123
592     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
593 ph10 122 segmentation fault instead of returning the appropriate error message.
594 ph10 134
595 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
596 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
597     This doesn't seem right; it now treats the CRLF combination as the line
598     ending, and so does not match in that case. It's only a pattern such as ^$
599     that would hit this one: something like ^ABC$ would have failed after \r
600     and then tried again after \r\n.
601    
602 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
603 ph10 134 in an attempt to make files that differ only in their line terminators
604     compare equal. This works on Linux.
605 ph10 142
606 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
607     as it exited. This is now fixed, thanks to valgrind.
608 ph10 142
609 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
610 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
611     was because its rules for how to advance for /g after matching an empty
612 ph10 143 string at the end of a line did not allow for this case. They now check for
613     it specially.
614 ph10 150
615     20. pcretest is supposed to handle patterns and data of any length, by
616     extending its buffers when necessary. It was getting this wrong when the
617 ph10 147 buffer for a data line had to be extended.
618 ph10 150
619 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
620 ph10 150 CRLF as a newline sequence.
621 ph10 152
622 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
623 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
624     I have nevertheless tidied it up.
625 ph10 111
626 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
627 ph10 123
628 ph10 153 24. Added a man page for pcre-config.
629 ph10 152
630 ph10 153
631 nigel 93 Version 7.0 19-Dec-06
632     ---------------------
633    
634     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
635     moving to gcc 4.1.1.
636    
637     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
638     sys/time.h, which is documented as needed for this function. It doesn't
639     seem to matter on Linux, but it showed up on some releases of OS X.
640    
641     3. It seems that there are systems where bytes whose values are greater than
642     127 match isprint() in the "C" locale. The "C" locale should be the
643     default when a C program starts up. In most systems, only ASCII printing
644     characters match isprint(). This difference caused the output from pcretest
645     to vary, making some of the tests fail. I have changed pcretest so that:
646    
647     (a) When it is outputting text in the compiled version of a pattern, bytes
648     other than 32-126 are always shown as hex escapes.
649    
650     (b) When it is outputting text that is a matched part of a subject string,
651     it does the same, unless a different locale has been set for the match
652     (using the /L modifier). In this case, it uses isprint() to decide.
653    
654     4. Fixed a major bug that caused incorrect computation of the amount of memory
655     required for a compiled pattern when options that changed within the
656     pattern affected the logic of the preliminary scan that determines the
657     length. The relevant options are -x, and -i in UTF-8 mode. The result was
658     that the computed length was too small. The symptoms of this bug were
659     either the PCRE error "internal error: code overflow" from pcre_compile(),
660     or a glibc crash with a message such as "pcretest: free(): invalid next
661     size (fast)". Examples of patterns that provoked this bug (shown in
662     pcretest format) are:
663    
664     /(?-x: )/x
665     /(?x)(?-x: \s*#\s*)/
666     /((?i)[\x{c0}])/8
667     /(?i:[\x{c0}])/8
668    
669     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
670     is now done differently.
671    
672     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
673     wrapper classes; (b) implement a new function in the C++ scanner that is
674     more efficient than the old way of doing things because it avoids levels of
675     recursion in the regex matching; (c) add a paragraph to the documentation
676     for the FullMatch() function.
677    
678     6. The escape sequence \n was being treated as whatever was defined as
679     "newline". Not only was this contrary to the documentation, which states
680     that \n is character 10 (hex 0A), but it also went horribly wrong when
681     "newline" was defined as CRLF. This has been fixed.
682    
683     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
684     was being set to -1 for the "end of line" case (supposedly a value that no
685     character can have). Though this value is never used (the check for end of
686     line is "zero bytes in current character"), it caused compiler complaints.
687     I've changed it to 0xffffffff.
688    
689     8. In pcre_version.c, the version string was being built by a sequence of
690     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
691     string (as it is for production releases) called a macro with an empty
692     argument. The C standard says the result of this is undefined. The gcc
693     compiler treats it as an empty string (which was what was wanted) but it is
694     reported that Visual C gives an error. The source has been hacked around to
695     avoid this problem.
696    
697     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
698     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
699     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
700     of them did).
701    
702     10. Originally, pcretest opened its input and output without "b"; then I was
703     told that "b" was needed in some environments, so it was added for release
704     5.0 to both the input and output. (It makes no difference on Unix-like
705     systems.) Later I was told that it is wrong for the input on Windows. I've
706     now abstracted the modes into two macros, to make it easier to fiddle with
707     them, and removed "b" from the input mode under Windows.
708    
709     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
710    
711     12. Added -help and --help to pcretest as an official way of being reminded
712     of the options.
713    
714     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
715     and pcrecpp.cc because they annoy compilers at high warning levels.
716    
717     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
718    
719     15. Fixed an occurrence of == in configure.ac that should have been = (shell
720     scripts are not C programs :-) and which was not noticed because it works
721     on Linux.
722    
723     16. pcretest is supposed to handle any length of pattern and data line (as one
724     line or as a continued sequence of lines) by extending its input buffer if
725     necessary. This feature was broken for very long pattern lines, leading to
726     a string of junk being passed to pcre_compile() if the pattern was longer
727     than about 50K.
728    
729     17. I have done a major re-factoring of the way pcre_compile() computes the
730     amount of memory needed for a compiled pattern. Previously, there was code
731     that made a preliminary scan of the pattern in order to do this. That was
732     OK when PCRE was new, but as the facilities have expanded, it has become
733     harder and harder to keep it in step with the real compile phase, and there
734     have been a number of bugs (see for example, 4 above). I have now found a
735     cunning way of running the real compile function in a "fake" mode that
736     enables it to compute how much memory it would need, while actually only
737     ever using a few hundred bytes of working memory and without too many
738     tests of the mode. This should make future maintenance and development
739     easier. A side effect of this work is that the limit of 200 on the nesting
740     depth of parentheses has been removed (though this was never a serious
741     limitation, I suspect). However, there is a downside: pcre_compile() now
742     runs more slowly than before (30% or more, depending on the pattern). I
743     hope this isn't a big issue. There is no effect on runtime performance.
744    
745     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
746     newline (only possible for the last line of a file) and it was a
747     pattern that set a locale (followed by /Lsomething), pcretest crashed.
748    
749     19. Added additional timing features to pcretest. (1) The -tm option now times
750     matching only, not compiling. (2) Both -t and -tm can be followed, as a
751     separate command line item, by a number that specifies the number of
752     repeats to use when timing. The default is 50000; this gives better
753     precision, but takes uncomfortably long for very large patterns.
754    
755     20. Extended pcre_study() to be more clever in cases where a branch of a
756     subpattern has no definite first character. For example, (a*|b*)[cd] would
757     previously give no result from pcre_study(). Now it recognizes that the
758     first character must be a, b, c, or d.
759    
760     21. There was an incorrect error "recursive call could loop indefinitely" if
761     a subpattern (or the entire pattern) that was being tested for matching an
762     empty string contained only one non-empty item after a nested subpattern.
763     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
764     incorrectly, because the \d was being skipped in the check.
765    
766     22. The pcretest program now has a new pattern option /B and a command line
767     option -b, which is equivalent to adding /B to every pattern. This causes
768     it to show the compiled bytecode, without the additional information that
769     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
770     is the same as /B/I).
771    
772     23. A new optimization is now able automatically to treat some sequences such
773     as a*b as a*+b. More specifically, if something simple (such as a character
774     or a simple class like \d) has an unlimited quantifier, and is followed by
775     something that cannot possibly match the quantified thing, the quantifier
776     is automatically "possessified".
777    
778     24. A recursive reference to a subpattern whose number was greater than 39
779     went wrong under certain circumstances in UTF-8 mode. This bug could also
780     have affected the operation of pcre_study().
781    
782     25. Realized that a little bit of performance could be had by replacing
783     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
784    
785     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
786    
787     27. Possessive quantifiers such as a++ were previously implemented by turning
788     them into atomic groups such as ($>a+). Now they have their own opcodes,
789     which improves performance. This includes the automatically created ones
790     from 23 above.
791    
792     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
793     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
794     the first matched character to be a colon. This applied both to named and
795     numbered groups.
796    
797     29. The ucpinternal.h header file was missing its idempotency #ifdef.
798    
799     30. I was sent a "project" file called libpcre.a.dev which I understand makes
800     building PCRE on Windows easier, so I have included it in the distribution.
801    
802     31. There is now a check in pcretest against a ridiculously large number being
803     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
804     loop, the loop is abandoned.
805    
806     32. Forward references to subpatterns in conditions such as (?(2)...) where
807     subpattern 2 is defined later cause pcre_compile() to search forwards in
808     the pattern for the relevant set of parentheses. This search went wrong
809     when there were unescaped parentheses in a character class, parentheses
810     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
811    
812     33. "Subroutine" calls and backreferences were previously restricted to
813     referencing subpatterns earlier in the regex. This restriction has now
814     been removed.
815    
816     34. Added a number of extra features that are going to be in Perl 5.10. On the
817     whole, these are just syntactic alternatives for features that PCRE had
818     previously implemented using the Python syntax or my own invention. The
819     other formats are all retained for compatibility.
820    
821     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
822     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
823     also .NET compatible.
824    
825     (b) A recursion or subroutine call to a named group can now be defined as
826     (?&name) as well as (?P>name).
827    
828     (c) A backreference to a named group can now be defined as \k<name> or
829     \k'name' as well as (?P=name). The new forms, as well as being in Perl
830     5.10, are also .NET compatible.
831    
832     (d) A conditional reference to a named group can now use the syntax
833     (?(<name>) or (?('name') as well as (?(name).
834    
835     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
836     groups (named and numbered) that are never evaluated inline, but can be
837     called as "subroutines" from elsewhere. In effect, the DEFINE condition
838     is always false. There may be only one alternative in such a group.
839    
840     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
841     as the simple (?(R). The condition is true only if the most recent
842     recursion is that of the given number or name. It does not search out
843     through the entire recursion stack.
844    
845     (g) The escape \gN or \g{N} has been added, where N is a positive or
846     negative number, specifying an absolute or relative reference.
847    
848     35. Tidied to get rid of some further signed/unsigned compiler warnings and
849     some "unreachable code" warnings.
850    
851     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
852     things, this adds five new scripts.
853    
854     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
855     There were also incompatibilities regarding the handling of \Q..\E inside
856     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
857     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
858    
859     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
860     matches an empty string, and forcibly breaks the loop. There were bugs in
861     this code in non-simple cases. For a pattern such as ^(a()*)* matched
862     against aaaa the result was just "a" rather than "aaaa", for example. Two
863     separate and independent bugs (that affected different cases) have been
864     fixed.
865    
866     39. Refactored the code to abolish the use of different opcodes for small
867     capturing bracket numbers. This is a tidy that I avoided doing when I
868     removed the limit on the number of capturing brackets for 3.5 back in 2001.
869     The new approach is not only tidier, it makes it possible to reduce the
870     memory needed to fix the previous bug (38).
871    
872     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
873     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
874     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
875     mode.
876    
877     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
878     report.
879    
880     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
881     copy construction and assignment in the C++ wrapper.
882    
883     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
884     couple of bugs that could have given wrong results in the "--newline=crlf"
885     case.
886    
887     44. Added a number of casts and did some reorganization of signed/unsigned int
888     variables following suggestions from Dair Grant. Also renamed the variable
889     "this" as "item" because it is a C++ keyword.
890    
891     45. Arranged for dftables to add
892    
893     #include "pcre_internal.h"
894    
895     to pcre_chartables.c because without it, gcc 4.x may remove the array
896     definition from the final binary if PCRE is built into a static library and
897     dead code stripping is activated.
898    
899     46. For an unanchored pattern, if a match attempt fails at the start of a
900     newline sequence, and the newline setting is CRLF or ANY, and the next two
901     characters are CRLF, advance by two characters instead of one.
902    
903    
904 nigel 91 Version 6.7 04-Jul-06
905     ---------------------
906    
907     1. In order to handle tests when input lines are enormously long, pcretest has
908     been re-factored so that it automatically extends its buffers when
909     necessary. The code is crude, but this _is_ just a test program. The
910     default size has been increased from 32K to 50K.
911    
912     2. The code in pcre_study() was using the value of the re argument before
913     testing it for NULL. (Of course, in any sensible call of the function, it
914     won't be NULL.)
915    
916     3. The memmove() emulation function in pcre_internal.h, which is used on
917     systems that lack both memmove() and bcopy() - that is, hardly ever -
918     was missing a "static" storage class specifier.
919    
920     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
921     containing an extended class (one that cannot be represented by a bitmap
922     because it contains high-valued characters or Unicode property items, e.g.
923     [\pZ]). Almost always one would set UTF-8 mode when processing such a
924     pattern, but PCRE should not loop if you do not (it no longer does).
925     [Detail: two cases were found: (a) a repeated subpattern containing an
926     extended class; (b) a recursive reference to a subpattern that followed a
927     previous extended class. It wasn't skipping over the extended class
928     correctly when UTF-8 mode was not set.]
929    
930     5. A negated single-character class was not being recognized as fixed-length
931     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
932     compile error "lookbehind assertion is not fixed length".
933    
934     6. The RunPerlTest auxiliary script was showing an unexpected difference
935     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
936     write a Perl script that can interpret lines of an input file either as
937     byte characters or as UTF-8, which is what "perltest" was being required to
938     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
939     can't do is switch easily at run time between having the "use utf8;" pragma
940     or not. In the end, I fudged it by using the RunPerlTest script to insert
941     "use utf8;" explicitly for the UTF-8 tests.
942    
943     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
944     the end of the subject string, contrary to the documentation and to what
945     Perl does. This was true of both matching functions. Now it matches only at
946     the start of the subject and immediately after *internal* newlines.
947    
948     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
949     a pointer to an int instead of a pointer to an unsigned long int. This
950     caused problems on 64-bit systems.
951    
952     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
953     instance of the 'standard' template library not being so standard".
954    
955     10. There was no check on the number of named subpatterns nor the maximum
956     length of a subpattern name. The product of these values is used to compute
957     the size of the memory block for a compiled pattern. By supplying a very
958     long subpattern name and a large number of named subpatterns, the size
959     computation could be caused to overflow. This is now prevented by limiting
960     the length of names to 32 characters, and the number of named subpatterns
961     to 10,000.
962    
963     11. Subpatterns that are repeated with specific counts have to be replicated in
964     the compiled pattern. The size of memory for this was computed from the
965     length of the subpattern and the repeat count. The latter is limited to
966     65535, but there was no limit on the former, meaning that integer overflow
967     could in principle occur. The compiled length of a repeated subpattern is
968     now limited to 30,000 bytes in order to prevent this.
969    
970     12. Added the optional facility to have named substrings with the same name.
971    
972     13. Added the ability to use a named substring as a condition, using the
973     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
974     are numbers (not recommended). Forward references are permitted.
975    
976     14. Added forward references in named backreferences (if you see what I mean).
977    
978     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
979     pattern could run off the end of the subject. For example, the pattern
980     "(?s)(.{1,5})"8 did this with the subject "ab".
981    
982     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
983     PCRE_CASELESS was set when matching characters that were quantified with ?
984     or *.
985    
986     17. A character class other than a single negated character that had a minimum
987     but no maximum quantifier - for example [ab]{6,} - was not handled
988     correctly by pce_dfa_exec(). It would match only one character.
989    
990     18. A valid (though odd) pattern that looked like a POSIX character
991     class but used an invalid character after [ (for example [[,abc,]]) caused
992     pcre_compile() to give the error "Failed: internal error: code overflow" or
993     in some cases to crash with a glibc free() error. This could even happen if
994     the pattern terminated after [[ but there just happened to be a sequence of
995     letters, a binary zero, and a closing ] in the memory that followed.
996    
997     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
998     over the years. Originally (before any Unicode support), just the bottom 8
999     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1000     output from "man perlunicode" includes this:
1001    
1002     The regular expression compiler produces polymorphic opcodes. That
1003     is, the pattern adapts to the data and automatically switches to
1004     the Unicode character scheme when presented with Unicode data--or
1005     instead uses a traditional byte scheme when presented with byte
1006     data.
1007    
1008     Sadly, a wide octal escape does not cause a switch, and in a string with
1009     no other multibyte characters, these octal escapes are treated as before.
1010     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1011     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1012     Unicode string.
1013    
1014     I have not perpetrated such confusion in PCRE. Up till now, it took just
1015     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1016     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1017     translate to the appropriate multibyte character.
1018    
1019     29. Applied some refactoring to reduce the number of warnings from Microsoft
1020     and Borland compilers. This has included removing the fudge introduced
1021     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1022     a warning about an unused variable.
1023    
1024     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1025     characters since release 4.0, because Perl (from release 5.004) does not.
1026     [Or at least, is documented not to: some releases seem to be in conflict
1027     with the documentation.] However, when a pattern was studied with
1028     pcre_study() and all its branches started with \s, PCRE still included VT
1029     as a possible starting character. Of course, this did no harm; it just
1030     caused an unnecessary match attempt.
1031    
1032     22. Removed a now-redundant internal flag bit that recorded the fact that case
1033     dependency changed within the pattern. This was once needed for "required
1034     byte" processing, but is no longer used. This recovers a now-scarce options
1035     bit. Also moved the least significant internal flag bit to the most-
1036     significant bit of the word, which was not previously used (hangover from
1037     the days when it was an int rather than a uint) to free up another bit for
1038     the future.
1039    
1040     23. Added support for CRLF line endings as well as CR and LF. As well as the
1041     default being selectable at build time, it can now be changed at runtime
1042     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1043     specify that it is scanning data with non-default line endings.
1044    
1045     24. Changed the definition of CXXLINK to make it agree with the definition of
1046     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1047    
1048     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1049     recursions. This makes a big different to stack usage for some patterns.
1050    
1051     26. If a subpattern containing a named recursion or subroutine reference such
1052     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1053     the space required for the compiled pattern went wrong and gave too small a
1054     value. Depending on the environment, this could lead to "Failed: internal
1055     error: code overflow at offset 49" or "glibc detected double free or
1056     corruption" errors.
1057    
1058     27. Applied patches from Google (a) to support the new newline modes and (b) to
1059     advance over multibyte UTF-8 characters in GlobalReplace.
1060    
1061     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1062     difference for some implementation of PCRE in some Windows version.
1063    
1064     29. Added some extra testing facilities to pcretest:
1065    
1066     \q<number> in a data line sets the "match limit" value
1067     \Q<number> in a data line sets the "match recursion limt" value
1068     -S <number> sets the stack size, where <number> is in megabytes
1069    
1070     The -S option isn't available for Windows.
1071    
1072    
1073 nigel 89 Version 6.6 06-Feb-06
1074     ---------------------
1075    
1076     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1077     in pcreposix.h. I have copied the definition from pcre.h.
1078    
1079     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1080     because pcre.h is no longer a built file.
1081    
1082     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1083     not normally included in the compiled code.
1084    
1085    
1086 nigel 87 Version 6.5 01-Feb-06
1087     ---------------------
1088    
1089     1. When using the partial match feature with pcre_dfa_exec(), it was not
1090     anchoring the second and subsequent partial matches at the new starting
1091     point. This could lead to incorrect results. For example, with the pattern
1092     /1234/, partially matching against "123" and then "a4" gave a match.
1093    
1094     2. Changes to pcregrep:
1095    
1096     (a) All non-match returns from pcre_exec() were being treated as failures
1097     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1098     error message is output. Some extra information is given for the
1099     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1100     probably the only errors that are likely to be caused by users (by
1101     specifying a regex that has nested indefinite repeats, for instance).
1102     If there are more than 20 of these errors, pcregrep is abandoned.
1103    
1104     (b) A binary zero was treated as data while matching, but terminated the
1105     output line if it was written out. This has been fixed: binary zeroes
1106     are now no different to any other data bytes.
1107    
1108     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1109     used to set a locale for matching. The --locale=xxxx long option has
1110     been added (no short equivalent) to specify a locale explicitly on the
1111     pcregrep command, overriding the environment variables.
1112    
1113     (d) When -B was used with -n, some line numbers in the output were one less
1114     than they should have been.
1115    
1116     (e) Added the -o (--only-matching) option.
1117    
1118     (f) If -A or -C was used with -c (count only), some lines of context were
1119     accidentally printed for the final match.
1120    
1121     (g) Added the -H (--with-filename) option.
1122    
1123     (h) The combination of options -rh failed to suppress file names for files
1124     that were found from directory arguments.
1125    
1126     (i) Added the -D (--devices) and -d (--directories) options.
1127    
1128     (j) Added the -F (--fixed-strings) option.
1129    
1130     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1131    
1132     (l) Added the --colo(u)r option.
1133    
1134     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1135     is not present by default.
1136    
1137     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1138     items such as (?R) or (?1), when the recursion could match a number of
1139     alternatives. If it matched one of the alternatives, but subsequently,
1140     outside the recursion, there was a failure, the code tried to back up into
1141     the recursion. However, because of the way PCRE is implemented, this is not
1142     possible, and the result was an incorrect result from the match.
1143    
1144     In order to prevent this happening, the specification of recursion has
1145     been changed so that all such subpatterns are automatically treated as
1146     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1147    
1148     4. I had overlooked the fact that, in some locales, there are characters for
1149     which isalpha() is true but neither isupper() nor islower() are true. In
1150     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1151     and ordfeminine) are like this. This affected the treatment of \w and \W
1152     when they appeared in character classes, but not when they appeared outside
1153     a character class. The bit map for "word" characters is now created
1154     separately from the results of isalnum() instead of just taking it from the
1155     upper, lower, and digit maps. (Plus the underscore character, of course.)
1156    
1157     5. The above bug also affected the handling of POSIX character classes such as
1158     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1159     permanent tables. Instead, the bit maps for such a class were previously
1160     created as the appropriate unions of the upper, lower, and digit bitmaps.
1161     Now they are created by subtraction from the [[:word:]] class, which has
1162     its own bitmap.
1163    
1164     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1165     It is created by subtracting the vertical space characters (\x09, \x0a,
1166     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1167     subtraction was done in the overall bitmap for a character class, meaning
1168     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1169     be recognized. This bug has been fixed.
1170    
1171     7. Patches from the folks at Google:
1172    
1173     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1174     real life, but is still worth protecting against".
1175    
1176     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1177     regular expressions".
1178    
1179     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1180     have it.
1181    
1182     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1183     "configure" and the latter not, in order to fix a problem somebody had
1184     with compiling the Arg class on HP-UX.
1185    
1186     (e) Improve the error-handling of the C++ wrapper a little bit.
1187    
1188     (f) New tests for checking recursion limiting.
1189    
1190     8. The pcre_memmove() function, which is used only if the environment does not
1191     have a standard memmove() function (and is therefore rarely compiled),
1192     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1193     returning a result (though PCRE never actually uses the result).
1194    
1195     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1196     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1197     returned instead of calling malloc() with an overflowing number that would
1198     most likely cause subsequent chaos.
1199    
1200     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1201    
1202     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1203     with this option is matched, the nmatch and pmatch options of regexec() are
1204     ignored.
1205    
1206     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1207     provided in case anyone wants to the the POSIX interface with UTF-8
1208     strings.
1209    
1210     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1211     C++ linking (needed for some HP-UX environments).
1212    
1213     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1214     (unused parameter) and in the pcre_printint() function (omitted "default"
1215     switch label when the default is to do nothing).
1216    
1217     15. Added some code to make it possible, when PCRE is compiled as a C++
1218     library, to replace subject pointers for pcre_exec() with a smart pointer
1219     class, thus making it possible to process discontinuous strings.
1220    
1221     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1222     much the same function. They were added by different people who were trying
1223     to make PCRE easy to compile on non-Unix systems. It has been suggested
1224     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1225     for compiling on Windows systems. I have therefore replaced it with
1226     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1227     defaults to "extern" for C or "extern C" for C++, which works fine on
1228     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1229     SCOPE with something explicit in config.h. In addition:
1230    
1231     (a) pcreposix.h still had just "extern" instead of either of these macros;
1232     I have replaced it with PCRE_DATA_SCOPE.
1233    
1234     (b) Functions such as _pcre_xclass(), which are internal to the library,
1235     but external in the C sense, all had PCRE_EXPORT in their definitions.
1236     This is apparently wrong for the Windows case, so I have removed it.
1237     (It makes no difference on Unix-like systems.)
1238    
1239     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1240     of recursive calls to match(). This is different to MATCH_LIMIT because
1241     that limits the total number of calls to match(), not all of which increase
1242     the depth of recursion. Limiting the recursion depth limits the amount of
1243     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1244     when PCRE is compiled, and changed at run time. A patch from Google adds
1245     this functionality to the C++ interface.
1246    
1247     18. Changes to the handling of Unicode character properties:
1248    
1249     (a) Updated the table to Unicode 4.1.0.
1250    
1251     (b) Recognize characters that are not in the table as "Cn" (undefined).
1252    
1253     (c) I revised the way the table is implemented to a much improved format
1254     which includes recognition of ranges. It now supports the ranges that
1255     are defined in UnicodeData.txt, and it also amalgamates other
1256     characters into ranges. This has reduced the number of entries in the
1257     table from around 16,000 to around 3,000, thus reducing its size
1258     considerably. I realized I did not need to use a tree structure after
1259     all - a binary chop search is just as efficient. Having reduced the
1260     number of entries, I extended their size from 6 bytes to 8 bytes to
1261     allow for more data.
1262    
1263     (d) Added support for Unicode script names via properties such as \p{Han}.
1264    
1265     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1266     matching that character.
1267    
1268     20. When matching a repeated Unicode property with a minimum greater than zero,
1269     (for example \pL{2,}), PCRE could look past the end of the subject if it
1270     reached it while seeking the minimum number of characters. This could
1271     happen only if some of the characters were more than one byte long, because
1272     there is a check for at least the minimum number of bytes.
1273    
1274     21. Refactored the implementation of \p and \P so as to be more general, to
1275     allow for more different types of property in future. This has changed the
1276     compiled form incompatibly. Anybody with saved compiled patterns that use
1277     \p or \P will have to recompile them.
1278    
1279     22. Added "Any" and "L&" to the supported property types.
1280    
1281     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1282     but give a compile time error if the value is greater than 0xff.
1283    
1284     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1285     accidentally not being installed or uninstalled.
1286    
1287     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1288     made were to insert the current release number. This seemed silly, because
1289     it made things harder for people building PCRE on systems that don't run
1290     "configure". I have turned pcre.h into a distributed file, no longer built
1291     by "configure", with the version identification directly included. There is
1292     no longer a pcre.h.in file.
1293    
1294     However, this change necessitated a change to the pcre-config script as
1295     well. It is built from pcre-config.in, and one of the substitutions was the
1296     release number. I have updated configure.ac so that ./configure now finds
1297     the release number by grepping pcre.h.
1298    
1299     26. Added the ability to run the tests under valgrind.
1300    
1301    
1302 nigel 85 Version 6.4 05-Sep-05
1303     ---------------------
1304    
1305     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1306     "--" to be printed when multiple files were scanned, even when none of the
1307     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1308     consider it to be a bug, and have restored the previous behaviour.
1309    
1310     2. A couple of code tidies to get rid of compiler warnings.
1311    
1312     3. The pcretest program used to cheat by referring to symbols in the library
1313     whose names begin with _pcre_. These are internal symbols that are not
1314     really supposed to be visible externally, and in some environments it is
1315     possible to suppress them. The cheating is now confined to including
1316     certain files from the library's source, which is a bit cleaner.
1317    
1318     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1319     file's purpose clearer.
1320    
1321     5. Reorganized pcre_ucp_findchar().
1322    
1323    
1324 nigel 83 Version 6.3 15-Aug-05
1325     ---------------------
1326    
1327     1. The file libpcre.pc.in did not have general read permission in the tarball.
1328    
1329     2. There were some problems when building without C++ support:
1330    
1331     (a) If C++ support was not built, "make install" and "make test" still
1332     tried to test it.
1333    
1334     (b) There were problems when the value of CXX was explicitly set. Some
1335     changes have been made to try to fix these, and ...
1336    
1337     (c) --disable-cpp can now be used to explicitly disable C++ support.
1338    
1339     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1340     backslash in a target when C++ was disabled. This confuses some
1341     versions of "make", apparently. Using an intermediate variable solves
1342     this. (Same for CPP_LOBJ.)
1343    
1344     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1345     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1346     necessary on certain architectures.
1347    
1348     4. Added a setting of -export-symbols-regex to the link command to remove
1349     those symbols that are exported in the C sense, but actually are local
1350     within the library, and not documented. Their names all begin with
1351     "_pcre_". This is not a perfect job, because (a) we have to except some
1352     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1353     available (and never for static libraries). I have made a note to try to
1354     find a way round (a) in the future.
1355    
1356    
1357 nigel 81 Version 6.2 01-Aug-05
1358     ---------------------
1359    
1360     1. There was no test for integer overflow of quantifier values. A construction
1361     such as {1111111111111111} would give undefined results. What is worse, if
1362     a minimum quantifier for a parenthesized subpattern overflowed and became
1363     negative, the calculation of the memory size went wrong. This could have
1364     led to memory overwriting.
1365    
1366     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1367    
1368     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1369     operating environments where this matters.
1370    
1371     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1372     PCRE options from within the C++ wrapper.
1373    
1374     5. Named capturing subpatterns were not being correctly counted when a pattern
1375     was compiled. This caused two problems: (a) If there were more than 100
1376     such subpatterns, the calculation of the memory needed for the whole
1377     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1378     back references of the form \12, where the number was greater than 9, were
1379     not recognized as back references, even though there were sufficient
1380     previous subpatterns.
1381    
1382     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1383     versions of gcc, e.g. 2.95.4.
1384    
1385    
1386 nigel 79 Version 6.1 21-Jun-05
1387     ---------------------
1388    
1389     1. There was one reference to the variable "posix" in pcretest.c that was not
1390     surrounded by "#if !defined NOPOSIX".
1391    
1392     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1393     the cross-check on the old pcre_info() function, for the benefit of the
1394     cut-down version of PCRE that is currently imported into Exim.
1395    
1396     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1397     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1398     patterns that start (?i) but I don't think that matters. The use of (?i) is
1399     just an example; this all applies to the other options as well.
1400    
1401     4. Since libtool seems to echo the compile commands it is issuing, the output
1402     from "make" can be reduced a bit by putting "@" in front of each libtool
1403     compile command.
1404    
1405     5. Patch from the folks at Google for configure.in to be a bit more thorough
1406     in checking for a suitable C++ installation before trying to compile the
1407     C++ stuff. This should fix a reported problem when a compiler was present,
1408     but no suitable headers.
1409    
1410     6. The man pages all had just "PCRE" as their title. I have changed them to
1411     be the relevant file name. I have also arranged that these names are
1412     retained in the file doc/pcre.txt, which is a concatenation in text format
1413     of all the man pages except the little individual ones for each function.
1414    
1415     7. The NON-UNIX-USE file had not been updated for the different set of source
1416     files that come with release 6. I also added a few comments about the C++
1417     wrapper.
1418    
1419    
1420 nigel 77 Version 6.0 07-Jun-05
1421     ---------------------
1422    
1423     1. Some minor internal re-organization to help with my DFA experiments.
1424    
1425     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1426     didn't matter for the library itself when fully configured, but did matter
1427     when compiling without UCP support, or within Exim, where the ucp files are
1428     not imported.
1429    
1430     3. Refactoring of the library code to split up the various functions into
1431     different source modules. The addition of the new DFA matching code (see
1432     below) to a single monolithic source would have made it really too
1433     unwieldy, quite apart from causing all the code to be include in a
1434     statically linked application, when only some functions are used. This is
1435     relevant even without the DFA addition now that patterns can be compiled in
1436     one application and matched in another.
1437    
1438     The downside of splitting up is that there have to be some external
1439     functions and data tables that are used internally in different modules of
1440     the library but which are not part of the API. These have all had their
1441     names changed to start with "_pcre_" so that they are unlikely to clash
1442     with other external names.
1443    
1444     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1445     a different (DFA) algorithm. Although it is slower than the original
1446     function, it does have some advantages for certain types of matching
1447     problem.
1448    
1449     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1450     including restarting after a partial match.
1451    
1452     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1453     defined when compiling for Windows was sent to me. I have put it into the
1454     code, though I have no means of testing or verifying it.
1455    
1456     7. Added the pcre_refcount() auxiliary function.
1457    
1458     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1459     match before or at the first newline in the subject string. In pcretest,
1460     the /f option on a pattern can be used to set this.
1461    
1462     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1463     would behave wrongly. This has been present in PCRE since release 4.0.
1464    
1465     10. A number of changes to the pcregrep command:
1466    
1467     (a) Refactored how -x works; insert ^(...)$ instead of setting
1468     PCRE_ANCHORED and checking the length, in preparation for adding
1469     something similar for -w.
1470    
1471     (b) Added the -w (match as a word) option.
1472    
1473     (c) Refactored the way lines are read and buffered so as to have more
1474     than one at a time available.
1475    
1476     (d) Implemented a pcregrep test script.
1477    
1478     (e) Added the -M (multiline match) option. This allows patterns to match
1479     over several lines of the subject. The buffering ensures that at least
1480     8K, or the rest of the document (whichever is the shorter) is available
1481     for matching (and similarly the previous 8K for lookbehind assertions).
1482    
1483     (f) Changed the --help output so that it now says
1484    
1485     -w, --word-regex(p)
1486    
1487     instead of two lines, one with "regex" and the other with "regexp"
1488     because that confused at least one person since the short forms are the
1489     same. (This required a bit of code, as the output is generated
1490     automatically from a table. It wasn't just a text change.)
1491    
1492     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1493     option but starts with a hyphen. Could be a pattern or a path name
1494     starting with a hyphen, for instance.
1495    
1496     (h) "-" can be given as a file name to represent stdin.
1497    
1498     (i) When file names are being printed, "(standard input)" is used for
1499     the standard input, for compatibility with GNU grep. Previously
1500     "<stdin>" was used.
1501    
1502     (j) The option --label=xxx can be used to supply a name to be used for
1503     stdin when file names are being printed. There is no short form.
1504    
1505     (k) Re-factored the options decoding logic because we are going to add
1506     two more options that take data. Such options can now be given in four
1507     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1508    
1509     (l) Added the -A, -B, and -C options for requesting that lines of context
1510     around matches be printed.
1511    
1512     (m) Added the -L option to print the names of files that do not contain
1513     any matching lines, that is, the complement of -l.
1514    
1515     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1516     continue to scan other files.
1517    
1518     (o) The -s option was incorrectly implemented. For compatibility with other
1519     greps, it now suppresses the error message for a non-existent or non-
1520     accessible file (but not the return code). There is a new option called
1521     -q that suppresses the output of matching lines, which was what -s was
1522     previously doing.
1523    
1524     (p) Added --include and --exclude options to specify files for inclusion
1525     and exclusion when recursing.
1526    
1527     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1528     Hopefully, it now does.
1529    
1530     12. Missing cast in pcre_study().
1531    
1532     13. Added an "uninstall" target to the makefile.
1533    
1534     14. Replaced "extern" in the function prototypes in Makefile.in with
1535     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1536     world, but is set differently for Windows.
1537    
1538     15. Added a second compiling function called pcre_compile2(). The only
1539     difference is that it has an extra argument, which is a pointer to an
1540     integer error code. When there is a compile-time failure, this is set
1541     non-zero, in addition to the error test pointer being set to point to an
1542     error message. The new argument may be NULL if no error number is required
1543     (but then you may as well call pcre_compile(), which is now just a
1544     wrapper). This facility is provided because some applications need a
1545     numeric error indication, but it has also enabled me to tidy up the way
1546     compile-time errors are handled in the POSIX wrapper.
1547    
1548     16. Added VPATH=.libs to the makefile; this should help when building with one
1549     prefix path and installing with another. (Or so I'm told by someone who
1550     knows more about this stuff than I do.)
1551    
1552     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1553     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1554     match everything, including newlines. This is not POSIX-compatible, but
1555     somebody wanted the feature. From pcretest it can be activated by using
1556     both the P and the s flags.
1557    
1558     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1559    
1560     19. libpcre.pc was being incorrectly installed as executable.
1561    
1562     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1563     it now also looks for '\r' so that it will work unmodified on Windows.
1564    
1565     21. Added Google's contributed C++ wrapper to the distribution.
1566    
1567     22. Added some untidy missing memory free() calls in pcretest, to keep
1568     Electric Fence happy when testing.
1569    
1570    
1571    
1572 nigel 75 Version 5.0 13-Sep-04
1573     ---------------------
1574    
1575     1. Internal change: literal characters are no longer packed up into items
1576     containing multiple characters in a single byte-string. Each character
1577     is now matched using a separate opcode. However, there may be more than one
1578     byte in the character in UTF-8 mode.
1579    
1580     2. The pcre_callout_block structure has two new fields: pattern_position and
1581     next_item_length. These contain the offset in the pattern to the next match
1582     item, and its length, respectively.
1583    
1584     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1585     insertion of callouts before each pattern item. Added the /C option to
1586     pcretest to make use of this.
1587    
1588     4. On the advice of a Windows user, the lines
1589    
1590     #if defined(_WIN32) || defined(WIN32)
1591     _setmode( _fileno( stdout ), 0x8000 );
1592     #endif /* defined(_WIN32) || defined(WIN32) */
1593    
1594     have been added to the source of pcretest. This apparently does useful
1595     magic in relation to line terminators.
1596    
1597     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1598     for the benefit of those environments where the "b" makes a difference.
1599    
1600     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1601     to know about it. I have put a hack into configure.in that adds in code
1602     to set GCC=yes if CC=icc. This seems to end up at a point in the
1603     generated configure script that is early enough to affect the setting of
1604     compiler options, which is what is needed, but I have no means of testing
1605     whether it really works. (The user who reported this had patched the
1606     generated configure script, which of course I cannot do.)
1607    
1608     LATER: After change 22 below (new libtool files), the configure script
1609     seems to know about icc (and also ecc). Therefore, I have commented out
1610     this hack in configure.in.
1611    
1612     7. Added support for pkg-config (2 patches were sent in).
1613    
1614     8. Negated POSIX character classes that used a combination of internal tables
1615     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1616     [[:^ascii]]. Typically, they would match almost any characters. The other
1617     POSIX classes were not broken in this way.
1618    
1619     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1620     to find the match, as PCRE was deluded into thinking that the match had to
1621     start at the start point or following a newline. The same bug applied to
1622     patterns with negative forward assertions or any backward assertions
1623     preceding ".*" at the start, unless the pattern required a fixed first
1624     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1625    
1626     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1627     starting at the last subject character, bytes beyond the end of the subject
1628     string were read.
1629    
1630     11. Renamed the variable "class" as "classbits" to make life easier for C++
1631     users. (Previously there was a macro definition, but it apparently wasn't
1632     enough.)
1633    
1634     12. Added the new field "tables" to the extra data so that tables can be passed
1635     in at exec time, or the internal tables can be re-selected. This allows
1636     a compiled regex to be saved and re-used at a later time by a different
1637     program that might have everything at different addresses.
1638    
1639     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1640     -R library as well as a -L library.
1641    
1642     14. The debugging options of pcretest (-d on the command line or D on a
1643     pattern) showed incorrect output for anything following an extended class
1644     that contained multibyte characters and which was followed by a quantifier.
1645    
1646     15. Added optional support for general category Unicode character properties
1647     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1648     support. It adds about 90K to the size of the library. The meanings of the
1649     inbuilt class escapes such as \d and \s have NOT been changed.
1650    
1651     16. Updated pcredemo.c to include calls to free() to release the memory for the
1652     compiled pattern.
1653    
1654     17. The generated file chartables.c was being created in the source directory
1655     instead of in the building directory. This caused the build to fail if the
1656     source directory was different from the building directory, and was
1657     read-only.
1658    
1659     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1660     file. No doubt somebody will tell me if they don't make sense... Also added
1661     Dan Mooney's comments about building on OpenVMS.
1662    
1663     19. Added support for partial matching via the PCRE_PARTIAL option for
1664     pcre_exec() and the \P data escape in pcretest.
1665    
1666     20. Extended pcretest with 3 new pattern features:
1667    
1668     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1669     write the compiled pattern to the file whose name is "rest-of-line".
1670     This is a straight binary dump of the data, with the saved pointer to
1671     the character tables forced to be NULL. The study data, if any, is
1672     written too. After writing, pcretest reads a new pattern.
1673    
1674     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1675     compiled pattern from the given file. There must not be any
1676     occurrences of "<" in the file name (pretty unlikely); if there are,
1677     pcretest will instead treat the initial "<" as a pattern delimiter.
1678     After reading in the pattern, pcretest goes on to read data lines as
1679     usual.
1680    
1681     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1682     and 16-bit fields in a compiled pattern, to simulate a pattern that
1683     was compiled on a host of opposite endianness.
1684    
1685     21. The pcre-exec() function can now cope with patterns that were compiled on
1686     hosts of opposite endianness, with this restriction:
1687    
1688     As for any compiled expression that is saved and used later, the tables
1689     pointer field cannot be preserved; the extra_data field in the arguments
1690     to pcre_exec() should be used to pass in a tables address if a value
1691     other than the default internal tables were used at compile time.
1692    
1693     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1694     now diagnosed as an error. Previously, most of the time, a negative number
1695     would have been treated as zero, but if in addition "ovector" was passed as
1696     NULL, a crash could occur.
1697    
1698     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1699     new versions from the libtool 1.5 distribution (the last one is a copy of
1700     a file called libtool.m4). This seems to have fixed the need to patch
1701     "configure" to support Darwin 1.3 (which I used to do). However, I still
1702     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1703     workstation).
1704    
1705     24. Changed the PCRE licence to be the more standard "BSD" licence.
1706    
1707    
1708 nigel 73 Version 4.5 01-Dec-03
1709     ---------------------
1710    
1711     1. There has been some re-arrangement of the code for the match() function so
1712     that it can be compiled in a version that does not call itself recursively.
1713     Instead, it keeps those local variables that need separate instances for
1714     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1715     needs to "recurse". Keeping track of where control must go is done by means
1716     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1717     hide most of the details from the main code, and operates only if
1718     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1719     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1720     operating.
1721    
1722     To make it easier for callers to provide specially tailored get/free
1723     functions for this usage, two new functions, pcre_stack_malloc, and
1724     pcre_stack_free, are used. They are always called in strict stacking order,
1725     and the size of block requested is always the same.
1726    
1727     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1728     PCRE has been compiled to use the stack or the heap for recursion. The
1729     -C option of pcretest uses this to show which version is compiled.
1730    
1731     A new data escape \S, is added to pcretest; it causes the amounts of store
1732     obtained and freed by both kinds of malloc/free at match time to be added
1733     to the output.
1734    
1735     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1736     what's available on my current Linux desktop machine.
1737    
1738     3. When matching a UTF-8 string, the test for a valid string at the start has
1739     been extended. If start_offset is not zero, PCRE now checks that it points
1740     to a byte that is the start of a UTF-8 character. If not, it returns
1741     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1742     this is necessary because there may be backward assertions in the pattern.
1743     When matching the same subject several times, it may save resources to use
1744     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1745    
1746     4. The code for checking the validity of UTF-8 strings has been tightened so
1747     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1748     containing "overlong sequences".
1749    
1750     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1751     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1752     should have been "&", but it just so happened that all the cases this let
1753     through by mistake were picked up later in the function.
1754    
1755     6. I had used a variable called "isblank" - this is a C99 function, causing
1756     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1757    
1758     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1759     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1760     so the version is shown; (c) stop "make test" echoing "./RunTest".
1761    
1762     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1763    
1764     9. The prototype for memmove() for systems that don't have it was using
1765     size_t, but the inclusion of the header that defines size_t was later. I've
1766     moved the #includes for the C headers earlier to avoid this.
1767    
1768     10. Added some adjustments to the code to make it easier to compiler on certain
1769     special systems:
1770    
1771     (a) Some "const" qualifiers were missing.
1772     (b) Added the macro EXPORT before all exported functions; by default this
1773     is defined to be empty.
1774     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1775     that it reads its output file name as an argument instead of writing
1776     to the standard output and assuming this can be redirected.
1777    
1778     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1779     class containing characters with values greater than 255, PCRE compilation
1780     went into a loop.
1781    
1782     12. A recursive reference to a subpattern that was within another subpattern
1783     that had a minimum quantifier of zero caused PCRE to crash. For example,
1784     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1785     recursion. If the recursively-called subpattern itself had a zero repeat,
1786     that was OK.
1787    
1788     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1789     buffer into which it was copied (for escape processing) was still set at
1790     1024, so long lines caused crashes.
1791    
1792     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1793     "internal error: code overflow...". This applied to any character class
1794     that was followed by a possessive quantifier.
1795    
1796     15. Modified the Makefile to add libpcre.la as a prerequisite for
1797     libpcreposix.la because I was told this is needed for a parallel build to
1798     work.
1799    
1800     16. If a pattern that contained .* following optional items at the start was
1801     studied, the wrong optimizing data was generated, leading to matching
1802     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1803     matching string must start with a or b or c. The correct conclusion for
1804     this pattern is that a match can start with any character.
1805    
1806    
1807 nigel 71 Version 4.4 13-Aug-03
1808     ---------------------
1809    
1810     1. In UTF-8 mode, a character class containing characters with values between
1811     127 and 255 was not handled correctly if the compiled pattern was studied.
1812     In fixing this, I have also improved the studying algorithm for such
1813     classes (slightly).
1814    
1815     2. Three internal functions had redundant arguments passed to them. Removal
1816     might give a very teeny performance improvement.
1817    
1818     3. Documentation bug: the value of the capture_top field in a callout is *one
1819     more than* the number of the hightest numbered captured substring.
1820    
1821     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1822     in incorrectly linking with a previously installed version. They now link
1823     explicitly with libpcre.la.
1824    
1825     5. configure.in no longer needs to recognize Cygwin specially.
1826    
1827     6. A problem in pcre.in for Windows platforms is fixed.
1828    
1829     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1830     pcretest, it used to include the size of the study block as part of its
1831     output. Unfortunately, the structure contains a field that has a different
1832     size on different hardware architectures. This meant that the tests that
1833     showed this size failed. As the block is currently always of a fixed size,
1834     this information isn't actually particularly useful in pcretest output, so
1835     I have just removed it.
1836    
1837     8. Three pre-processor statements accidentally did not start in column 1.
1838     Sadly, there are *still* compilers around that complain, even though
1839     standard C has not required this for well over a decade. Sigh.
1840    
1841     9. In pcretest, the code for checking callouts passed small integers in the
1842     callout_data field, which is a void * field. However, some picky compilers
1843     complained about the casts involved for this on 64-bit systems. Now
1844     pcretest passes the address of the small integer instead, which should get
1845     rid of the warnings.
1846    
1847     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1848     both compile and run time, and gives an error if an invalid UTF-8 sequence
1849     is found. There is a option for disabling this check in cases where the
1850     string is known to be correct and/or the maximum performance is wanted.
1851    
1852     11. In response to a bug report, I changed one line in Makefile.in from
1853    
1854     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1855     to
1856     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1857    
1858     to look similar to other lines, but I have no way of telling whether this
1859     is the right thing to do, as I do not use Windows. No doubt I'll get told
1860     if it's wrong...
1861    
1862    
1863 nigel 69 Version 4.3 21-May-03
1864     ---------------------
1865    
1866     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1867     Makefile.
1868    
1869     2. Some refactoring to improve the quality of the code:
1870    
1871     (i) The utf8_table... variables are now declared "const".
1872    
1873     (ii) The code for \cx, which used the "case flipping" table to upper case
1874     lower case letters, now just substracts 32. This is ASCII-specific,
1875     but the whole concept of \cx is ASCII-specific, so it seems
1876     reasonable.
1877    
1878     (iii) PCRE was using its character types table to recognize decimal and
1879     hexadecimal digits in the pattern. This is silly, because it handles
1880     only 0-9, a-f, and A-F, but the character types table is locale-
1881     specific, which means strange things might happen. A private
1882     table is now used for this - though it costs 256 bytes, a table is
1883     much faster than multiple explicit tests. Of course, the standard
1884     character types table is still used for matching digits in subject
1885     strings against \d.
1886    
1887     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1888     ending in _t are). So I've renamed it as ESC_tee.
1889    
1890     3. The first argument for regexec() in the POSIX wrapper should have been
1891     defined as "const".
1892    
1893     4. Changed pcretest to use malloc() for its buffers so that they can be
1894     Electric Fenced for debugging.
1895    
1896     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1897     to read one or more bytes before the start of the subject string. Often this
1898     had no effect on PCRE's behaviour, but in some circumstances it could
1899     provoke a segmentation fault.
1900    
1901     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1902     to try to read one or more bytes before the start of the subject string.
1903    
1904     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1905     UTF-8 support could misbehave in various ways if the subject string
1906     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1907     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1908     back over UTF-8 characters.)
1909    
1910    
1911 nigel 67 Version 4.2 14-Apr-03
1912     ---------------------
1913    
1914     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1915    
1916     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1917     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1918     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1919     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1920     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1921     and BUILD_EXEEXT
1922     Note: automatic setting of the BUILD variables is not yet working
1923     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1924     compile-time but not at link-time
1925     [LINK]: use for linking executables only
1926     make different versions for Windows and non-Windows
1927     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1928     libraries
1929     [LINK_FOR_BUILD]: new variable
1930     [OBJEXT]: use throughout
1931     [EXEEXT]: use throughout
1932     <winshared>: new target
1933     <wininstall>: new target
1934     <dftables.o>: use native compiler
1935     <dftables>: use native linker
1936     <install>: handle Windows platform correctly
1937     <clean>: ditto
1938     <check>: ditto
1939     copy DLL to top builddir before testing
1940    
1941     As part of these changes, -no-undefined was removed again. This was reported
1942     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1943     in any case.
1944    
1945     3. Some tidies to get rid of compiler warnings:
1946    
1947     . In the match_data structure, match_limit was an unsigned long int, whereas
1948     match_call_count was an int. I've made them both unsigned long ints.
1949    
1950     . In pcretest the fact that a const uschar * doesn't automatically cast to
1951     a void * provoked a warning.
1952    
1953     . Turning on some more compiler warnings threw up some "shadow" variables
1954     and a few more missing casts.
1955    
1956     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1957     option, a class that contained a single character with a value between 128
1958     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1959    
1960     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1961     option, a class that contained several characters, but with at least one
1962     whose value was between 128 and 255 caused PCRE to crash.
1963    
1964    
1965 nigel 65 Version 4.1 12-Mar-03
1966     ---------------------
1967 nigel 63
1968 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
1969     needed, and a string in dftables.c that was longer than standard compilers are
1970     required to support.
1971    
1972     2. Compiling with Sun's compiler found a few more places where the code could
1973     be tidied up in order to avoid warnings.
1974    
1975     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1976     first of these names is deprecated in the latest Autoconf in favour of the name
1977     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1978     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1979     analogy I have changed it to CFLAGS_FOR_BUILD.
1980    
1981     4. Added -no-undefined to the linking command in the Makefile, because this is
1982     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1983     linking step for the pcreposix library.
1984    
1985     5. PCRE was failing to diagnose the case of two named groups with the same
1986     name.
1987    
1988     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1989     literal character that is needed in the subject for a match, and scans along to
1990     ensure that it is present before embarking on the full matching process. This
1991     saves time in cases of nested unlimited repeats that are never going to match.
1992     Problem: the scan can take a lot of time if the subject is very long (e.g.
1993     megabytes), thus penalizing straightforward matches. It is now done only if the
1994     amount of subject to be scanned is less than 1000 bytes.
1995    
1996     7. A lesser problem with the same optimization is that it was recording the
1997     first character of an anchored pattern as "needed", thus provoking a search
1998     right along the subject, even when the first match of the pattern was going to
1999     fail. The "needed" character is now not set for anchored patterns, unless it
2000     follows something in the pattern that is of non-fixed length. Thus, it still
2001     fulfils its original purpose of finding quick non-matches in cases of nested
2002     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2003    
2004    
2005     Version 4.0 17-Feb-03
2006     ---------------------
2007    
2008 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2009     extended to the end of string, PCRE compiled incorrect data. This could lead to
2010     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2011    
2012     2. Moved to autoconf 2.53 and libtool 1.4.2.
2013    
2014     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2015     the special perltest8 script is no longer needed - all the tests can be run
2016     from a single perltest script.
2017    
2018     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2019     by \s. It has now been removed in PCRE. This means it isn't recognized as
2020     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2021     class [:space:] *does* include VT, thereby creating a mess.
2022    
2023     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2024     space and tab.
2025    
2026     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2027     its new features into the main test script, reducing the number of scripts.
2028    
2029     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2030     were backward compatible, and made the (?i) apply to the whole pattern, as if
2031     /i were given. Now it behaves more logically, and applies the option setting
2032     only to what follows. PCRE has been changed to follow suit. However, if it
2033     finds options settings right at the start of the pattern, it extracts them into
2034     the global options, as before. Thus, they show up in the info data.
2035    
2036     8. Added support for the \Q...\E escape sequence. Characters in between are
2037     treated as literals. This is slightly different from Perl in that $ and @ are
2038     also handled as literals inside the quotes. In Perl, they will cause variable
2039     interpolation. Note the following examples:
2040    
2041     Pattern PCRE matches Perl matches
2042    
2043     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2044     \Qabc\$xyz\E abc\$xyz abc\$xyz
2045     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2046    
2047     For compatibility with Perl, \Q...\E sequences are recognized inside character
2048     classes as well as outside them.
2049    
2050     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2051     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2052     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2053     signed/unsigned warnings.
2054    
2055     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2056     option for pcretest, so I've replaced it by a simple function that does just
2057     that job.
2058    
2059     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2060     "pcregrep -".
2061    
2062     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2063     Java package. This provides some syntactic sugar for simple cases of what my
2064     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2065     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2066     item, you can use this simplified notation. Note that only makes sense with
2067     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2068     greediness, whatever the setting of the PCRE_UNGREEDY option.
2069    
2070     13. A change of greediness default within a pattern was not taking effect at
2071     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2072     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2073     was abstracted outside.
2074    
2075     14. PCRE now supports the \G assertion. It is true when the current matching
2076     position is at the start point of the match. This differs from \A when the
2077     starting offset is non-zero. Used with the /g option of pcretest (or similar
2078     code), it works in the same way as it does for Perl's /g option. If all
2079     alternatives of a regex begin with \G, the expression is anchored to the start
2080     match position, and the "anchored" flag is set in the compiled expression.
2081    
2082     15. Some bugs concerning the handling of certain option changes within patterns
2083     have been fixed. These applied to options other than (?ims). For example,
2084     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2085     been the other way round. Some of this was related to change 7 above.
2086    
2087     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2088     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2089     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2090     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2091    
2092     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2093     mode. Unlike ".", it always matches newline, whatever the setting of
2094     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2095     assertions. Perl allows it, but it doesn't (in general) work because it can't
2096     calculate the length of the lookbehind. At least, that's the case for Perl
2097     5.8.0 - I've been told they are going to document that it doesn't work in
2098     future.
2099    
2100     18. Added an error diagnosis for escapes that PCRE does not support: these are
2101     \L, \l, \N, \P, \p, \U, \u, and \X.
2102    
2103     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2104     reading past the end of the pattern in cases such as /[abcd/.
2105    
2106     20. PCRE was getting more memory than necessary for patterns with classes that
2107     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2108    
2109     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2110     compiling PCRE for use with Virtual Pascal.
2111    
2112     22. Small fix to the Makefile to make it work properly if the build is done
2113     outside the source tree.
2114    
2115     23. Added a new extension: a condition to go with recursion. If a conditional
2116     subpattern starts with (?(R) the "true" branch is used if recursion has
2117     happened, whereas the "false" branch is used only at the top level.
2118    
2119     24. When there was a very long string of literal characters (over 255 bytes
2120     without UTF support, over 250 bytes with UTF support), the computation of how
2121     much memory was required could be incorrect, leading to segfaults or other
2122     strange effects.
2123    
2124     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2125     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2126     there was a subsequent back reference to those brackets. This meant that, for
2127     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2128     possible to check for precisely this case. All we can do is abandon the
2129     optimization if .* occurs inside capturing brackets when there are any back
2130     references whatsoever. (See below for a better fix that came later.)
2131    
2132     26. The handling of the optimization for finding the first character of a
2133     non-anchored pattern, and for finding a character that is required later in the
2134     match were failing in some cases. This didn't break the matching; it just
2135     failed to optimize when it could. The way this is done has been re-implemented.
2136    
2137     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2138    
2139     28. Added a new feature that provides some of the functionality that Perl
2140     provides with (?{...}). The facility is termed a "callout". The way it is done
2141     in PCRE is for the caller to provide an optional function, by setting
2142     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2143     global variable. By default it is unset, which disables all calling out. To get
2144     the function called, the regex must include (?C) at appropriate points. This
2145     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2146     This provides a means of identifying different callout points. When PCRE
2147     reaches such a point in the regex, if pcre_callout has been set, the external
2148     function is called. It is provided with data in a structure called
2149     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2150     matching continues; if it returns a non-zero value, the match at the current
2151     point fails. However, backtracking will occur if possible. [This was changed
2152     later and other features added - see item 49 below.]
2153    
2154     29. pcretest is upgraded to test the callout functionality. It provides a
2155     callout function that displays information. By default, it shows the start of
2156     the match and the current position in the text. There are some new data escapes
2157     to vary what happens:
2158    
2159     \C+ in addition, show current contents of captured substrings
2160     \C- do not supply a callout function
2161     \C!n return 1 when callout number n is reached
2162     \C!n!m return 1 when callout number n is reached for the mth time
2163    
2164     30. If pcregrep was called with the -l option and just a single file name, it
2165     output "<stdin>" if a match was found, instead of the file name.
2166    
2167     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2168     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2169     pcre_exec(). This saves a malloc/free per call. The default value of
2170     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2171     when configuring.
2172    
2173     32. The default maximum size of a compiled pattern is 64K. There have been a
2174     few cases of people hitting this limit. The code now uses macros to handle the
2175     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2176     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2177     configuring. Tests 2 and 5 work only with 2-byte links because they output
2178     debugging information about compiled patterns.
2179    
2180     33. Internal code re-arrangements:
2181    
2182     (a) Moved the debugging function for printing out a compiled regex into
2183     its own source file (printint.c) and used #include to pull it into
2184     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2185     separate copies.
2186    
2187     (b) Defined the list of op-code names for debugging as a macro in
2188     internal.h so that it is next to the definition of the opcodes.
2189    
2190     (c) Defined a table of op-code lengths for simpler skipping along compiled
2191     code. This is again a macro in internal.h so that it is next to the
2192     definition of the opcodes.
2193    
2194     34. Added support for recursive calls to individual subpatterns, along the
2195     lines of Robin Houston's patch (but implemented somewhat differently).
2196    
2197     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2198     allow it to read and process whole directories in Win32. This code was
2199     contributed by Lionel Fourquaux; it has not been tested by me.
2200    
2201     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2202     used to name a group. Names consist of alphanumerics and underscores, and must
2203     be unique. Back references use the syntax (?P=name) and recursive calls use
2204     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2205     numbers. The function pcre_fullinfo() can be used after compilation to extract
2206     a name/number map. There are three relevant calls:
2207    
2208     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2209     PCRE_INFO_NAMECOUNT yields the number of entries
2210     PCRE_INFO_NAMETABLE yields a pointer to the map.
2211    
2212     The map is a vector of fixed-size entries. The size of each entry depends on
2213     the length of the longest name used. The first two bytes of each entry are the
2214     group number, most significant byte first. There follows the corresponding
2215     name, zero terminated. The names are in alphabetical order.
2216    
2217     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2218     case instead of 255. Making it the same both with and without UTF-8 support
2219     means that the same test output works with both.
2220    
2221     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2222     calling malloc() with a zero argument.
2223    
2224     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2225     optimization. I've improved things by keeping a bitmap of backreferences with
2226     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2227     fact referenced, the optimization can be applied. It is unlikely that a
2228     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2229     the match to follow \n) will appear inside brackets with a number greater than
2230     31, but if it does, any back reference > 31 suppresses the optimization.
2231    
2232     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2233     of disabling numbered capturing parentheses. Any opening parenthesis that is
2234     not followed by ? behaves as if it were followed by ?: but named parentheses
2235     can still be used for capturing (and they will acquire numbers in the usual
2236     way).
2237    
2238     41. Redesigned the return codes from the match() function into yes/no/error so
2239     that errors can be passed back from deep inside the nested calls. A malloc
2240     failure while inside a recursive subpattern call now causes the
2241     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2242    
2243     42. It is now possible to set a limit on the number of times the match()
2244     function is called in a call to pcre_exec(). This facility makes it possible to
2245     limit the amount of recursion and backtracking, though not in a directly
2246     obvious way, because the match() function is used in a number of different
2247     circumstances. The count starts from zero for each position in the subject
2248     string (for non-anchored patterns). The default limit is, for compatibility, a
2249     large number, namely 10 000 000. You can change this in two ways:
2250    
2251     (a) When configuring PCRE before making, you can use --with-match-limit=n
2252     to set a default value for the compiled library.
2253    
2254     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2255     a different value is set. See 45 below.
2256    
2257     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2258    
2259     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2260     of things that can be changed at compile time. The first argument specifies
2261     what is wanted and the second points to where the information is to be placed.
2262     The current list of available information is:
2263    
2264     PCRE_CONFIG_UTF8
2265    
2266     The output is an integer that is set to one if UTF-8 support is available;
2267     otherwise it is set to zero.
2268    
2269     PCRE_CONFIG_NEWLINE
2270    
2271     The output is an integer that it set to the value of the code that is used for
2272     newline. It is either LF (10) or CR (13).
2273    
2274     PCRE_CONFIG_LINK_SIZE
2275    
2276     The output is an integer that contains the number of bytes used for internal
2277     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2278    
2279     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2280    
2281     The output is an integer that contains the threshold above which the POSIX
2282     interface uses malloc() for output vectors. See item 31 above.
2283    
2284     PCRE_CONFIG_MATCH_LIMIT
2285    
2286     The output is an unsigned integer that contains the default limit of the number
2287     of match() calls in a pcre_exec() execution. See 42 above.
2288    
2289     44. pcretest has been upgraded by the addition of the -C option. This causes it
2290     to extract all the available output from the new pcre_config() function, and to
2291     output it. The program then exits immediately.
2292    
2293     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2294     order to support additional features. One way would have been to define
2295     pcre_exec2() (for example) with extra arguments, but this would not have been
2296     extensible, and would also have required all calls to the original function to
2297     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2298     is used for passing in "extra" data from pcre_study().
2299    
2300     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2301     contains the following fields:
2302    
2303     flags a bitmap indicating which of the following fields are set
2304     study_data opaque data from pcre_study()
2305     match_limit a way of specifying a limit on match() calls for a specific
2306     call to pcre_exec()
2307     callout_data data for callouts (see 49 below)
2308    
2309     The flag bits are also defined in pcre.h, and are
2310    
2311     PCRE_EXTRA_STUDY_DATA
2312     PCRE_EXTRA_MATCH_LIMIT
2313     PCRE_EXTRA_CALLOUT_DATA
2314    
2315     The pcre_study() function now returns one of these new pcre_extra blocks, with
2316     the actual study data pointed to by the study_data field, and the
2317     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2318     before. That is, this change is entirely upwards-compatible and requires no
2319     change to existing code.
2320    
2321     If you want to pass in additional data to pcre_exec(), you can either place it
2322     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2323     block.
2324    
2325     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2326     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2327     times with different match limits, until it finds the minimum value needed for
2328     pcre_exec() to complete. The value is then output. This can be instructive; for
2329     most simple matches the number is quite small, but for pathological cases it
2330     gets very large very quickly.
2331    
2332     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2333     returns the size of the data block pointed to by the study_data field in a
2334     pcre_extra block, that is, the value that was passed as the argument to
2335     pcre_malloc() when PCRE was getting memory in which to place the information
2336     created by pcre_study(). The fourth argument should point to a size_t variable.
2337     pcretest has been extended so that this information is shown after a successful
2338     pcre_study() call when information about the compiled regex is being displayed.
2339    
2340     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2341     because what follows is always an absolute path. (Later: it turns out that this
2342     is more than cosmetic for MinGW, because it doesn't like empty path
2343     components.)
2344    
2345     49. Some changes have been made to the callout feature (see 28 above):
2346    
2347     (i) A callout function now has three choices for what it returns:
2348    
2349     0 => success, carry on matching
2350     > 0 => failure at this point, but backtrack if possible
2351     < 0 => serious error, return this value from pcre_exec()
2352    
2353     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2354     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2355     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2356     use by callout functions. It will never be used by PCRE itself.
2357    
2358     (ii) The pcre_extra structure (see 45 above) has a void * field called
2359     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2360     pcre_callout_block structure has a field of the same name. The contents of
2361     the field passed in the pcre_extra structure are passed to the callout
2362     function in the corresponding field in the callout block. This makes it
2363     easier to use the same callout-containing regex from multiple threads. For
2364     testing, the pcretest program has a new data escape
2365    
2366     \C*n pass the number n (may be negative) as callout_data
2367    
2368     If the callout function in pcretest receives a non-zero value as
2369     callout_data, it returns that value.
2370    
2371     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2372     there were some redundant $(CFLAGS) in commands that are now specified as
2373     $(LINK), which already includes $(CFLAGS).
2374    
2375     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2376     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2377     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2378     one-byte characters throughout. Note that case-insensitive matching applies
2379     only to characters whose values are less than 256. PCRE doesn't support the
2380     notion of cases for higher-valued characters.
2381    
2382     (i) A character class whose characters are all within 0-255 is handled as
2383     a bit map, and the map is inverted for negative classes. Previously, a
2384     character > 255 always failed to match such a class; however it should
2385     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2386    
2387     (ii) A negated character class with a single character < 255 is coded as
2388     "not this character" (OP_NOT). This wasn't working properly when the test
2389     character was multibyte, either singly or repeated.
2390    
2391     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2392     mode, for example: \x{100}{2,3}.
2393    
2394     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2395     singly or repeated) now correctly test multibyte characters. However,
2396     PCRE doesn't recognize any characters with values greater than 255 as
2397     digits, spaces, or word characters. Such characters always match \D, \S,
2398     and \W, and never match \d, \s, or \w.
2399    
2400     (v) Classes may now contain characters and character ranges with values
2401     greater than 255. For example: [ab\x{100}-\x{400}].
2402    
2403     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2404     PCRE in UTF-8 mode.
2405    
2406     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2407     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2408     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2409     value.)
2410    
2411     53. The single man page has become too large. I have therefore split it up into
2412     a number of separate man pages. These also give rise to individual HTML pages;
2413     these are now put in a separate directory, and there is an index.html page that
2414     lists them all. Some hyperlinking between the pages has been installed.
2415    
2416     54. Added convenience functions for handling named capturing parentheses.
2417    
2418     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2419     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2420     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2421     are faulted.
2422    
2423     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2424     calling configure. These values are used when compiling the dftables.c program
2425     which is run to generate the source of the default character tables. They
2426     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2427     you will need to set these values.
2428    
2429     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2430    
2431    
2432     Version 3.9 02-Jan-02
2433 nigel 61 ---------------------
2434    
2435     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2436    
2437     2. If --disable-static was given, the building process failed when trying to
2438     build pcretest and pcregrep. (For some reason it was using libtool to compile
2439     them, which is not right, as they aren't part of the library.)
2440    
2441    
2442 nigel 59 Version 3.8 18-Dec-01
2443     ---------------------
2444    
2445     1. The experimental UTF-8 code was completely screwed up. It was packing the
2446     bytes in the wrong order. How dumb can you get?
2447    
2448    
2449 nigel 57 Version 3.7 29-Oct-01
2450     ---------------------
2451    
2452     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2453     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2454     this didn't happen under Solaris 8, where I normally test things.
2455    
2456 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2457     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2458     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2459     this fix an hour or so after the initial 3.7 release.)
2460 nigel 57
2461 nigel 59
2462 nigel 55 Version 3.6 23-Oct-01
2463     ---------------------
2464    
2465     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2466     offsets passed as NULL with zero offset count.
2467    
2468     2. The config.guess and config.sub files had not been updated when I moved to
2469     the latest autoconf.
2470    
2471    
2472 nigel 53 Version 3.5 15-Aug-01
2473     ---------------------
2474 nigel 5
2475 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2476     had been forgotten.
2477    
2478     2. By using declared but undefined structures, we can avoid using "void"
2479     definitions in pcre.h while keeping the internal definitions of the structures
2480     private.
2481    
2482     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2483     user point of view, this means that both static and shared libraries are built
2484     by default, but this can be individually controlled. More of the work of
2485     handling this static/shared cases is now inside libtool instead of PCRE's make
2486     file.
2487    
2488     4. The pcretest utility is now installed along with pcregrep because it is
2489     useful for users (to test regexs) and by doing this, it automatically gets
2490     relinked by libtool. The documentation has been turned into a man page, so
2491     there are now .1, .txt, and .html versions in /doc.
2492    
2493     5. Upgrades to pcregrep:
2494     (i) Added long-form option names like gnu grep.
2495     (ii) Added --help to list all options with an explanatory phrase.
2496     (iii) Added -r, --recursive to recurse into sub-directories.
2497     (iv) Added -f, --file to read patterns from a file.
2498    
2499     6. pcre_exec() was referring to its "code" argument before testing that
2500     argument for NULL (and giving an error if it was NULL).
2501    
2502     7. Upgraded Makefile.in to allow for compiling in a different directory from
2503     the source directory.
2504    
2505     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2506     options bits, the pointer it was passed was to an int instead of to an unsigned
2507     long int. This mattered only on 64-bit systems.
2508    
2509     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2510     generated) instead of pcre.in, which it its source. Also made the same change
2511     in several of the .c files.
2512    
2513     10. A new release of gcc defines printf() as a macro, which broke pcretest
2514     because it had an ifdef in the middle of a string argument for printf(). Fixed
2515     by using separate calls to printf().
2516    
2517     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2518     script, to force use of CR or LF instead of \n in the source. On non-Unix
2519     systems, the value can be set in config.h.
2520    
2521     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2522     absolute limit. Changed the text of the error message to make this clear, and
2523     likewise updated the man page.
2524    
2525     13. The limit of 99 on the number of capturing subpatterns has been removed.
2526     The new limit is 65535, which I hope will not be a "real" limit.
2527    
2528    
2529 nigel 51 Version 3.4 22-Aug-00
2530     ---------------------
2531    
2532     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2533    
2534     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2535    
2536    
2537 nigel 49 Version 3.3 01-Aug-00
2538     ---------------------
2539    
2540     1. If an octal character was given, but the value was greater than \377, it
2541     was not getting masked to the least significant bits, as documented. This could
2542     lead to crashes in some systems.
2543    
2544     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2545     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2546    
2547     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2548     These just pass their arguments on to (pcre_free)(), but they are provided
2549     because some uses of PCRE bind it to non-C systems that can call its functions,
2550     but cannot call free() or pcre_free() directly.
2551    
2552     4. Add "make test" as a synonym for "make check". Corrected some comments in
2553     the Makefile.
2554    
2555     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2556     Makefile.
2557    
2558     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2559     command called pgrep for grepping around the active processes.
2560    
2561     7. Added the beginnings of support for UTF-8 character strings.
2562    
2563     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2564     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2565     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2566     out for the ar command.)
2567    
2568    
2569 nigel 47 Version 3.2 12-May-00
2570     ---------------------
2571    
2572     This is purely a bug fixing release.
2573    
2574     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2575     of ZA. This was just one example of several cases that could provoke this bug,
2576     which was introduced by change 9 of version 2.00. The code for breaking
2577     infinite loops after an iteration that matches an empty string was't working
2578     correctly.
2579    
2580     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2581     when matched against abbab (for example). After matching an empty string, it
2582     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2583     caused it to match further down the string than it should.
2584    
2585     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2586     was there because it doesn't seem to be needed, and it causes trouble on some
2587     systems, as it is not a Standard C header. It has been removed.
2588    
2589     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2590     were reported on the Macintosh. The changes were from
2591    
2592     while ((c = *(++ptr)) != 0 && c != '\n');
2593     to
2594     while ((c = *(++ptr)) != 0 && c != '\n') ;
2595    
2596     Totally extraordinary, but if that's what it takes...
2597    
2598     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2599     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2600     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2601     assumes the way PCRE uses memmove() (always moving upwards).
2602    
2603     6. PCRE is being used in one environment where strchr() is not available. There
2604     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2605     faster code anyway.
2606    
2607    
2608 nigel 45 Version 3.1 09-Feb-00
2609     ---------------------
2610    
2611     The only change in this release is the fixing of some bugs in Makefile.in for
2612     the "install" target:
2613    
2614     (1) It was failing to install pcreposix.h.
2615    
2616     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2617    
2618    
2619 nigel 43 Version 3.0 01-Feb-00
2620     ---------------------
2621 nigel 41
2622     1. Add support for the /+ modifier to perltest (to output $` like it does in
2623     pcretest).
2624    
2625     2. Add support for the /g modifier to perltest.
2626    
2627     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2628     matches null strings.
2629    
2630     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2631     pattern. Perl treats empty patterns specially - it reuses the most recent
2632     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2633     effect.
2634    
2635     5. The POSIX interface was broken in that it was just handing over the POSIX
2636     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2637     required a bigger vector, with some working space on the end. This means that
2638     the POSIX wrapper now has to get and free some memory, and copy the results.
2639    
2640 nigel 43 6. Added some simple autoconf support, placing the test data and the
2641     documentation in separate directories, re-organizing some of the
2642     information files, and making it build pcre-config (a GNU standard). Also added
2643     libtool support for building PCRE as a shared library, which is now the
2644     default.
2645 nigel 41
2646 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2647     09 are not valid octal constants. Single digits will be used for minor values
2648     less than 10.
2649    
2650     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2651     existing programs that set these in the POSIX interface can use PCRE without
2652     modification.
2653    
2654     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2655     return all that pcre_info() returns, plus additional data. The pcre_info()
2656     function is retained for compatibility, but is considered to be obsolete.
2657    
2658     10. Added experimental recursion feature (?R) to handle one common case that
2659     Perl 5.6 will be able to do with (?p{...}).
2660    
2661     11. Added support for POSIX character classes like [:alpha:], which Perl is
2662     adopting.
2663    
2664    
2665 nigel 39 Version 2.08 31-Aug-99
2666     ----------------------
2667    
2668     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2669     trying to match at the startoffset position, but instead was moving forward to
2670     the next newline as if a previous match had failed.
2671    
2672     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2673     and could get into a loop if a null string was matched other than at the start
2674     of the subject.
2675    
2676     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2677     be distinguished at compile time, and for completeness also added PCRE_DATE.
2678    
2679     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2680     in GnuWin32 environments.
2681    
2682    
2683 nigel 37 Version 2.07 29-Jul-99
2684     ----------------------
2685    
2686     1. The documentation is now supplied in plain text form and HTML as well as in
2687     the form of man page sources.
2688    
2689     2. C++ compilers don't like assigning (void *) values to other pointer types.
2690     In particular this affects malloc(). Although there is no problem in Standard
2691     C, I've put in casts to keep C++ compilers happy.
2692    
2693     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2694     should be (const char *).
2695    
2696     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2697     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2698     However, I haven't made this a standard facility. The documentation doesn't
2699     mention it, and the Makefile doesn't support it.
2700    
2701     5. The Makefile now contains an "install" target, with editable destinations at
2702     the top of the file. The pcretest program is not installed.
2703    
2704     6. pgrep -V now gives the PCRE version number and date.
2705    
2706     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2707     causing the entire string to be ignored, instead of just the last character.
2708    
2709     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2710     non-matching string, it can take a very, very long time, even for strings of
2711     quite modest length, because of the nested recursion. PCRE now does better in
2712     some of these cases. It does this by remembering the last required literal
2713     character in the pattern, and pre-searching the subject to ensure it is present
2714     before running the real match. In other words, it applies a heuristic to detect
2715     some types of certain failure quickly, and in the above example, if presented
2716     with a string that has no trailing " it gives "no match" very quickly.
2717    
2718     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2719     other alternatives are tried instead.
2720    
2721    
2722 nigel 35 Version 2.06 09-Jun-99
2723     ----------------------
2724    
2725     1. Change pcretest's output for amount of store used to show just the code
2726     space, because the remainder (the data block) varies in size between 32-bit and
2727     64-bit systems.
2728    
2729     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2730     start matching at. This allows lookbehinds to work when searching for multiple
2731     occurrences in a string.
2732    
2733     3. Added additional options to pcretest for testing multiple occurrences:
2734    
2735     /+ outputs the rest of the string that follows a match
2736     /g loops for multiple occurrences, using the new startoffset argument
2737     /G loops for multiple occurrences by passing an incremented pointer
2738    
2739     4. PCRE wasn't doing the "first character" optimization for patterns starting
2740     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2741     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2742     the letter 'x'. On long subject strings, this gives a significant speed-up.
2743    
2744    
2745 nigel 33 Version 2.05 21-Apr-99
2746     ----------------------
2747    
2748     1. Changed the type of magic_number from int to long int so that it works
2749     properly on 16-bit systems.
2750    
2751     2. Fixed a bug which caused patterns starting with .* not to work correctly
2752     when the subject string contained newline characters. PCRE was assuming
2753     anchoring for such patterns in all cases, which is not correct because .* will
2754     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2755     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2756     must be retried after every newline in the subject.
2757    
2758    
2759 nigel 31 Version 2.04 18-Feb-99
2760     ----------------------
2761    
2762     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2763     computation of the store needed to hold the pattern was incorrect (too large).
2764     If such patterns were nested a few deep, this could multiply and become a real
2765     problem.
2766    
2767     2. Added /M option to pcretest to show the memory requirement of a specific
2768     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2769    
2770     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2771     compiled in such a way that the backtracking after subsequent failure was
2772     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2773     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2774    
2775    
2776 nigel 29 Version 2.03 02-Feb-99
2777     ----------------------
2778    
2779     1. Fixed typo and small mistake in man page.
2780    
2781 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2782     LICENCE file containing the conditions.
2783 nigel 29
2784     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2785     Perl, that is the internal \ allows the delimiter to be included in the
2786     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2787     the final delimiter, add \ to the end of the pattern (to test the error).
2788    
2789     4. Added the convenience functions for extracting substrings after a successful
2790     match. Updated pcretest to make it able to test these functions.
2791    
2792    
2793 nigel 27 Version 2.02 14-Jan-99
2794     ----------------------
2795    
2796     1. Initialized the working variables associated with each extraction so that
2797     their saving and restoring doesn't refer to uninitialized store.
2798    
2799     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2800     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2801     fix the problem.
2802    
2803     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2804     calls, and wasn't printing the correct value for compiling calls. Increased the
2805     default value of LOOPREPEAT, and the number of significant figures in the
2806     times.
2807    
2808     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2809    
2810     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2811     a building problem on Windows NT with a FAT file system.
2812    
2813    
2814 nigel 25 Version 2.01 21-Oct-98
2815     ----------------------
2816    
2817     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2818     to character tables built by pcre_maketables() in the current locale. If NULL
2819     is passed, the default tables are used.
2820    
2821    
2822 nigel 23 Version 2.00 24-Sep-98
2823 nigel 21 ----------------------
2824    
2825 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2826     it any more.
2827    
2828     2. Allow quantification of (?>) groups, and make it work correctly.
2829    
2830     3. The first character computation wasn't working for (?>) groups.
2831    
2832     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2833     end of the subject) and add 5.005's \z, which really does match only at the
2834     very end of the subject.
2835    
2836     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2837    
2838     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2839     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2840     localized options. All options to pcre_study() were also removed.
2841    
2842     7. Add other new features from 5.005:
2843    
2844     $(?<= positive lookbehind
2845     $(?<! negative lookbehind
2846     (?imsx-imsx) added the unsetting capability
2847     such a setting is global if at outer level; local otherwise
2848     (?imsx-imsx:) non-capturing groups with option setting
2849     (?(cond)re|re) conditional pattern matching
2850    
2851     A backreference to itself in a repeated group matches the previous
2852     captured string.
2853    
2854     8. General tidying up of studying (both automatic and via "study")
2855     consequential on the addition of new assertions.
2856    
2857     9. As in 5.005, unlimited repeated groups that could match an empty substring
2858     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2859     runtime if any iteration does actually match an empty substring.
2860    
2861     10. Include the RunTest script in the distribution.
2862    
2863     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2864     discrepancies, some of which were old and were also with respect to 5.004. They
2865     have now been fixed.
2866    
2867    
2868     Version 1.09 28-Apr-98
2869     ----------------------
2870    
2871 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2872     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2873     program crashes, or just wrong answers. This did not apply to negated classes
2874     containing more than one character, or to minima other than one.
2875    
2876    
2877 nigel 19 Version 1.08 27-Mar-98
2878     ----------------------
2879    
2880     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2881    
2882     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2883     latter must appear before anything that relies on it in the pattern.
2884    
2885    
2886 nigel 17 Version 1.07 16-Feb-98
2887     ----------------------
2888    
2889     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2890     repeat of a potentially empty string).
2891    
2892    
2893 nigel 15 Version 1.06 23-Jan-98
2894     ----------------------
2895    
2896     1. Added Markus Oberhumer's little patches for C++.
2897    
2898     2. Literal strings longer than 255 characters were broken.
2899    
2900    
2901 nigel 13 Version 1.05 23-Dec-97
2902     ----------------------
2903    
2904     1. Negated character classes containing more than one character were failing if
2905     PCRE_CASELESS was set at run time.
2906    
2907    
2908 nigel 11 Version 1.04 19-Dec-97
2909     ----------------------
2910    
2911     1. Corrected the man page, where some "const" qualifiers had been omitted.
2912    
2913     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2914     input syntax.
2915    
2916     3. Fixed memory leak which occurred when a regex with back references was
2917     matched with an offsets vector that wasn't big enough. The temporary memory
2918     that is used in this case wasn't being freed if the match failed.
2919    
2920     4. Tidied pcretest to ensure it frees memory that it gets.
2921    
2922     5. Temporary memory was being obtained in the case where the passed offsets
2923     vector was exactly big enough.
2924    
2925     6. Corrected definition of offsetof() from change 5 below.
2926    
2927     7. I had screwed up change 6 below and broken the rules for the use of
2928     setjmp(). Now fixed.
2929    
2930    
2931 nigel 9 Version 1.03 18-Dec-97
2932     ----------------------
2933    
2934     1. A erroneous regex with a missing opening parenthesis was correctly
2935     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2936     on some systems.
2937    
2938     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2939     it was reported that one broken compiler failed on the former because "code" is
2940     also an independent variable.
2941    
2942     3. The erroneous regex a[]b caused an array overrun reference.
2943    
2944     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2945     fail on data ending with that character. (It was going on too far, and checking
2946     the next character, typically a binary zero.) This was specific to the
2947     optimized code for single-character negative classes.
2948    
2949     5. Added a contributed patch from the TIN world which does the following:
2950    
2951     + Add an undef for memmove, in case the the system defines a macro for it.
2952    
2953     + Add a definition of offsetof(), in case there isn't one. (I don't know
2954     the reason behind this - offsetof() is part of the ANSI standard - but
2955     it does no harm).
2956    
2957     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2958     most of the places where whitespace preceded '#'. I have given up and
2959     allowed the remaining 2 cases to be at the margin.
2960    
2961     + Rename some variables in pcre to eliminate shadowing. This seems very
2962     pedantic, but does no harm, of course.
2963    
2964     6. Moved the call to setjmp() into its own function, to get rid of warnings
2965     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2966    
2967     7. Constructs such as \d{8,} were compiling into the equivalent of
2968 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2969 nigel 9 outcome, but in this particular case used more store than had been allocated,
2970     which caused the bug to be discovered because it threw up an internal error.
2971    
2972     8. The debugging code in both pcre and pcretest for outputting the compiled
2973     form of a regex was going wrong in the case of back references followed by
2974     curly-bracketed repeats.
2975    
2976    
2977 nigel 7 Version 1.02 12-Dec-97
2978     ----------------------
2979    
2980     1. Typos in pcre.3 and comments in the source fixed.
2981    
2982     2. Applied a contributed patch to get rid of places where it used to remove
2983     'const' from variables, and fixed some signed/unsigned and uninitialized
2984     variable warnings.
2985    
2986     3. Added the "runtest" target to Makefile.
2987    
2988     4. Set default compiler flag to -O2 rather than just -O.
2989    
2990    
2991 nigel 5 Version 1.01 19-Nov-97
2992     ----------------------
2993    
2994     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2995     like /([ab]*)*/, that is, for classes with more than one character in them.
2996    
2997     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2998     as /((?>a*))*/ (a PCRE_EXTRA facility).
2999    
3000    
3001     Version 1.00 18-Nov-97
3002     ----------------------
3003    
3004     1. Added compile-time macros to support systems such as SunOS4 which don't have
3005     memmove() or strerror() but have other things that can be used instead.
3006    
3007     2. Arranged that "make clean" removes the executables.
3008    
3009    
3010 nigel 3 Version 0.99 27-Oct-97
3011     ----------------------
3012    
3013     1. Fixed bug in code for optimizing classes with only one character. It was
3014     initializing a 32-byte map regardless, which could cause it to run off the end
3015     of the memory it had got.
3016    
3017     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3018    
3019    
3020     Version 0.98 22-Oct-97
3021     ----------------------
3022    
3023     1. Fixed bug in code for handling temporary memory usage when there are more
3024     back references than supplied space in the ovector. This could cause segfaults.
3025    
3026    
3027     Version 0.97 21-Oct-97
3028     ----------------------
3029    
3030     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3031    
3032     2. Optimized negated single characters not to use a bit map.
3033    
3034     3. Brought error texts together as macro definitions; clarified some of them;
3035     fixed one that was wrong - it said "range out of order" when it meant "invalid
3036     escape sequence".
3037    
3038     4. Changed some char * arguments to const char *.
3039    
3040     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3041    
3042     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3043     pcretest.
3044    
3045    
3046     Version 0.96 16-Oct-97
3047     ----------------------
3048    
3049     1. Added a simple "pgrep" utility to the distribution.
3050    
3051     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3052     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3053     where "ddd" means "one or more decimal digits".
3054    
3055     3. Fixed serious bug. If a pattern had a back reference, but the call to
3056     pcre_exec() didn't supply a large enough ovector to record the related
3057     identifying subpattern, the match always failed. PCRE now remembers the number
3058     of the largest back reference, and gets some temporary memory in which to save
3059     the offsets during matching if necessary, in order to ensure that
3060     backreferences always work.
3061    
3062     4. Increased the compatibility with Perl in a number of ways:
3063    
3064     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3065     to request this handling. The option can be set at compile or exec time.
3066    
3067     (b) $ matches before a terminating newline by default; an option
3068     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3069     mode). The option can be set at compile or exec time.
3070    
3071     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3072     the same as Perl's. If the decimal number it represents is less than 10
3073     or there aren't that many previous left capturing parentheses, an octal
3074     escape is read. Inside a character class, it's always an octal escape,
3075     even if it is a single digit.
3076    
3077     (d) An escaped but undefined alphabetic character is taken as a literal,
3078     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3079     escapes.
3080    
3081     (e) {0} is now permitted. (The previous item is removed from the compiled
3082     pattern).
3083    
3084     5. Changed all the names of code files so that the basic parts are no longer
3085     than 10 characters, and abolished the teeny "globals.c" file.
3086    
3087     6. Changed the handling of character classes; they are now done with a 32-byte
3088     bit map always.
3089    
3090     7. Added the -d and /D options to pcretest to make it possible to look at the
3091     internals of compilation without having to recompile pcre.
3092    
3093    
3094     Version 0.95 23-Sep-97
3095     ----------------------
3096    
3097     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3098     \x20 at the start of a run of normal characters. These were being treated as
3099     real characters, instead of the source characters being re-checked.
3100    
3101    
3102     Version 0.94 18-Sep-97
3103     ----------------------
3104    
3105     1. The functions are now thread-safe, with the caveat that the global variables
3106     containing pointers to malloc() and free() or alternative functions are the
3107     same for all threads.
3108    
3109     2. Get pcre_study() to generate a bitmap of initial characters for non-
3110     anchored patterns when this is possible, and use it if passed to pcre_exec().
3111    
3112    
3113     Version 0.93 15-Sep-97
3114     ----------------------
3115    
3116     1. /(b)|(:+)/ was computing an incorrect first character.
3117    
3118     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3119     but not actually doing anything yet.
3120    
3121     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3122     as Perl does (e.g. [-az] or [az-]).
3123    
3124     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3125     all possible positions.
3126    
3127     5. Split up into different modules to avoid including unneeded functions in a
3128     compiled binary. However, compile and exec are still in one module. The "study"
3129     function is split off.
3130    
3131     6. The character tables are now in a separate module whose source is generated
3132     by an auxiliary program - but can then be edited by hand if required. There are
3133     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3134     toupper() in the code.
3135    
3136     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3137     make them global. Abolish the function for setting them, as the caller can now
3138     set them directly.
3139    
3140    
3141     Version 0.92 11-Sep-97
3142     ----------------------
3143    
3144     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3145     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3146    
3147     2. Caseless matching was not working in character classes if the characters in
3148     the pattern were in upper case.
3149    
3150     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3151    
3152     4. Make PCRE_ANCHORED public and accept as a compile option.
3153    
3154     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3155     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3156     pass them.
3157    
3158     6. Give an error if bad option bits passed at compile or run time.
3159    
3160     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3161     pcretest to cause it to pass that flag.
3162    
3163     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3164     options, and the first character, if set.
3165    
3166     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3167    
3168    
3169     Version 0.91 10-Sep-97
3170     ----------------------
3171    
3172     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3173     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3174    
3175     2. PCRE was looping on encountering an indefinitely repeated back reference to
3176     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3177     Perl does - treats the match as successful.
3178    
3179     ****

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