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Revision 201 - (hide annotations) (download)
Thu Aug 2 08:37:31 2007 UTC (7 years ago) by ph10
File size: 132682 byte(s)
Update version number; use %I64U instead of %llu under MingGW in 
pcrecpp_unittest.

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

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