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Revision 141 - (hide annotations) (download)
Fri Mar 30 15:46:27 2007 UTC (7 years, 6 months ago) by ph10
File size: 126210 byte(s)
Fixed obscure bug when matching a null string in multiline mode with 
newline=any.

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

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