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Revision 215 - (hide annotations) (download)
Wed Aug 15 14:20:05 2007 UTC (6 years, 11 months ago) by ph10
File size: 135799 byte(s)
Fixed overrun for missing ] with a forward reference, e.g. /(?1)\c[/.

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

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