ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log

Revision 228 - (hide annotations) (download)
Tue Aug 28 13:37:37 2007 UTC (7 years, 7 months ago) by ph10
File size: 138559 byte(s)
Final version number changes for the 7.3 release.

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


Name Value
svn:eol-style native
svn:keywords "Author Date Id Revision Url"

ViewVC Help
Powered by ViewVC 1.1.12