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Revision 160 - (hide annotations) (download)
Wed May 2 10:58:35 2007 UTC (7 years, 11 months ago) by ph10
File size: 127240 byte(s)
Fix RunGrepTest for make distcheck (previous change added a bug).

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


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