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Revision 234 - (hide annotations) (download)
Tue Sep 11 11:36:27 2007 UTC (6 years, 7 months ago) by ph10
File size: 140194 byte(s)
Macros for snprintf, strtoll, strtoull when compiling the C++ things under 
Windows.

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

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