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Revision 270 - (hide annotations) (download)
Fri Nov 16 19:55:16 2007 UTC (6 years, 9 months ago) by ph10
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Diagnose conditional numerical reference to a non-existent subpattern.

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

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