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Revision 302 - (hide annotations) (download)
Sun Jan 20 19:12:46 2008 UTC (6 years, 6 months ago) by ph10
File size: 148842 byte(s)
Exclude "long long" test in pcrecpp_unittest when HAVE_LONG_LONG is not 
defined.

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

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