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Revision 43 - (hide annotations) (download)
Sat Feb 24 21:39:21 2007 UTC (7 years, 4 months ago) by nigel
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Load pcre-3.0 into code/trunk.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 nigel 5
5 nigel 43 Version 3.0 01-Feb-00
6     ---------------------
7 nigel 41
8     1. Add support for the /+ modifier to perltest (to output $` like it does in
9     pcretest).
10    
11     2. Add support for the /g modifier to perltest.
12    
13     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
14     matches null strings.
15    
16     4. Fix perltest so that it doesn't do unwanted things when fed an empty
17     pattern. Perl treats empty patterns specially - it reuses the most recent
18     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
19     effect.
20    
21     5. The POSIX interface was broken in that it was just handing over the POSIX
22     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
23     required a bigger vector, with some working space on the end. This means that
24     the POSIX wrapper now has to get and free some memory, and copy the results.
25    
26 nigel 43 6. Added some simple autoconf support, placing the test data and the
27     documentation in separate directories, re-organizing some of the
28     information files, and making it build pcre-config (a GNU standard). Also added
29     libtool support for building PCRE as a shared library, which is now the
30     default.
31 nigel 41
32 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
33     09 are not valid octal constants. Single digits will be used for minor values
34     less than 10.
35    
36     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
37     existing programs that set these in the POSIX interface can use PCRE without
38     modification.
39    
40     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
41     return all that pcre_info() returns, plus additional data. The pcre_info()
42     function is retained for compatibility, but is considered to be obsolete.
43    
44     10. Added experimental recursion feature (?R) to handle one common case that
45     Perl 5.6 will be able to do with (?p{...}).
46    
47     11. Added support for POSIX character classes like [:alpha:], which Perl is
48     adopting.
49    
50    
51 nigel 39 Version 2.08 31-Aug-99
52     ----------------------
53    
54     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
55     trying to match at the startoffset position, but instead was moving forward to
56     the next newline as if a previous match had failed.
57    
58     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
59     and could get into a loop if a null string was matched other than at the start
60     of the subject.
61    
62     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
63     be distinguished at compile time, and for completeness also added PCRE_DATE.
64    
65     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
66     in GnuWin32 environments.
67    
68    
69 nigel 37 Version 2.07 29-Jul-99
70     ----------------------
71    
72     1. The documentation is now supplied in plain text form and HTML as well as in
73     the form of man page sources.
74    
75     2. C++ compilers don't like assigning (void *) values to other pointer types.
76     In particular this affects malloc(). Although there is no problem in Standard
77     C, I've put in casts to keep C++ compilers happy.
78    
79     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
80     should be (const char *).
81    
82     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
83     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
84     However, I haven't made this a standard facility. The documentation doesn't
85     mention it, and the Makefile doesn't support it.
86    
87     5. The Makefile now contains an "install" target, with editable destinations at
88     the top of the file. The pcretest program is not installed.
89    
90     6. pgrep -V now gives the PCRE version number and date.
91    
92     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
93     causing the entire string to be ignored, instead of just the last character.
94    
95     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
96     non-matching string, it can take a very, very long time, even for strings of
97     quite modest length, because of the nested recursion. PCRE now does better in
98     some of these cases. It does this by remembering the last required literal
99     character in the pattern, and pre-searching the subject to ensure it is present
100     before running the real match. In other words, it applies a heuristic to detect
101     some types of certain failure quickly, and in the above example, if presented
102     with a string that has no trailing " it gives "no match" very quickly.
103    
104     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
105     other alternatives are tried instead.
106    
107    
108 nigel 35 Version 2.06 09-Jun-99
109     ----------------------
110    
111     1. Change pcretest's output for amount of store used to show just the code
112     space, because the remainder (the data block) varies in size between 32-bit and
113     64-bit systems.
114    
115     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
116     start matching at. This allows lookbehinds to work when searching for multiple
117     occurrences in a string.
118    
119     3. Added additional options to pcretest for testing multiple occurrences:
120    
121     /+ outputs the rest of the string that follows a match
122     /g loops for multiple occurrences, using the new startoffset argument
123     /G loops for multiple occurrences by passing an incremented pointer
124    
125     4. PCRE wasn't doing the "first character" optimization for patterns starting
126     with \b or \B, though it was doing it for other lookbehind assertions. That is,
127     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
128     the letter 'x'. On long subject strings, this gives a significant speed-up.
129    
130    
131 nigel 33 Version 2.05 21-Apr-99
132     ----------------------
133    
134     1. Changed the type of magic_number from int to long int so that it works
135     properly on 16-bit systems.
136    
137     2. Fixed a bug which caused patterns starting with .* not to work correctly
138     when the subject string contained newline characters. PCRE was assuming
139     anchoring for such patterns in all cases, which is not correct because .* will
140     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
141     DOTALL is set at top level; otherwise it knows that patterns starting with .*
142     must be retried after every newline in the subject.
143    
144    
145 nigel 31 Version 2.04 18-Feb-99
146     ----------------------
147    
148     1. For parenthesized subpatterns with repeats whose minimum was zero, the
149     computation of the store needed to hold the pattern was incorrect (too large).
150     If such patterns were nested a few deep, this could multiply and become a real
151     problem.
152    
153     2. Added /M option to pcretest to show the memory requirement of a specific
154     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
155    
156     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
157     compiled in such a way that the backtracking after subsequent failure was
158     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
159     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
160    
161    
162 nigel 29 Version 2.03 02-Feb-99
163     ----------------------
164    
165     1. Fixed typo and small mistake in man page.
166    
167 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
168     LICENCE file containing the conditions.
169 nigel 29
170     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
171     Perl, that is the internal \ allows the delimiter to be included in the
172     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
173     the final delimiter, add \ to the end of the pattern (to test the error).
174    
175     4. Added the convenience functions for extracting substrings after a successful
176     match. Updated pcretest to make it able to test these functions.
177    
178    
179 nigel 27 Version 2.02 14-Jan-99
180     ----------------------
181    
182     1. Initialized the working variables associated with each extraction so that
183     their saving and restoring doesn't refer to uninitialized store.
184    
185     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
186     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
187     fix the problem.
188    
189     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
190     calls, and wasn't printing the correct value for compiling calls. Increased the
191     default value of LOOPREPEAT, and the number of significant figures in the
192     times.
193    
194     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
195    
196     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
197     a building problem on Windows NT with a FAT file system.
198    
199    
200 nigel 25 Version 2.01 21-Oct-98
201     ----------------------
202    
203     1. Changed the API for pcre_compile() to allow for the provision of a pointer
204     to character tables built by pcre_maketables() in the current locale. If NULL
205     is passed, the default tables are used.
206    
207    
208 nigel 23 Version 2.00 24-Sep-98
209 nigel 21 ----------------------
210    
211 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
212     it any more.
213    
214     2. Allow quantification of (?>) groups, and make it work correctly.
215    
216     3. The first character computation wasn't working for (?>) groups.
217    
218     4. Correct the implementation of \Z (it is permitted to match on the \n at the
219     end of the subject) and add 5.005's \z, which really does match only at the
220     very end of the subject.
221    
222     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
223    
224     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
225     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
226     localized options. All options to pcre_study() were also removed.
227    
228     7. Add other new features from 5.005:
229    
230     $(?<= positive lookbehind
231     $(?<! negative lookbehind
232     (?imsx-imsx) added the unsetting capability
233     such a setting is global if at outer level; local otherwise
234     (?imsx-imsx:) non-capturing groups with option setting
235     (?(cond)re|re) conditional pattern matching
236    
237     A backreference to itself in a repeated group matches the previous
238     captured string.
239    
240     8. General tidying up of studying (both automatic and via "study")
241     consequential on the addition of new assertions.
242    
243     9. As in 5.005, unlimited repeated groups that could match an empty substring
244     are no longer faulted at compile time. Instead, the loop is forcibly broken at
245     runtime if any iteration does actually match an empty substring.
246    
247     10. Include the RunTest script in the distribution.
248    
249     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
250     discrepancies, some of which were old and were also with respect to 5.004. They
251     have now been fixed.
252    
253    
254     Version 1.09 28-Apr-98
255     ----------------------
256    
257 nigel 21 1. A negated single character class followed by a quantifier with a minimum
258     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
259     program crashes, or just wrong answers. This did not apply to negated classes
260     containing more than one character, or to minima other than one.
261    
262    
263 nigel 19 Version 1.08 27-Mar-98
264     ----------------------
265    
266     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
267    
268     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
269     latter must appear before anything that relies on it in the pattern.
270    
271    
272 nigel 17 Version 1.07 16-Feb-98
273     ----------------------
274    
275     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
276     repeat of a potentially empty string).
277    
278    
279 nigel 15 Version 1.06 23-Jan-98
280     ----------------------
281    
282     1. Added Markus Oberhumer's little patches for C++.
283    
284     2. Literal strings longer than 255 characters were broken.
285    
286    
287 nigel 13 Version 1.05 23-Dec-97
288     ----------------------
289    
290     1. Negated character classes containing more than one character were failing if
291     PCRE_CASELESS was set at run time.
292    
293    
294 nigel 11 Version 1.04 19-Dec-97
295     ----------------------
296    
297     1. Corrected the man page, where some "const" qualifiers had been omitted.
298    
299     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
300     input syntax.
301    
302     3. Fixed memory leak which occurred when a regex with back references was
303     matched with an offsets vector that wasn't big enough. The temporary memory
304     that is used in this case wasn't being freed if the match failed.
305    
306     4. Tidied pcretest to ensure it frees memory that it gets.
307    
308     5. Temporary memory was being obtained in the case where the passed offsets
309     vector was exactly big enough.
310    
311     6. Corrected definition of offsetof() from change 5 below.
312    
313     7. I had screwed up change 6 below and broken the rules for the use of
314     setjmp(). Now fixed.
315    
316    
317 nigel 9 Version 1.03 18-Dec-97
318     ----------------------
319    
320     1. A erroneous regex with a missing opening parenthesis was correctly
321     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
322     on some systems.
323    
324     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
325     it was reported that one broken compiler failed on the former because "code" is
326     also an independent variable.
327    
328     3. The erroneous regex a[]b caused an array overrun reference.
329    
330     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
331     fail on data ending with that character. (It was going on too far, and checking
332     the next character, typically a binary zero.) This was specific to the
333     optimized code for single-character negative classes.
334    
335     5. Added a contributed patch from the TIN world which does the following:
336    
337     + Add an undef for memmove, in case the the system defines a macro for it.
338    
339     + Add a definition of offsetof(), in case there isn't one. (I don't know
340     the reason behind this - offsetof() is part of the ANSI standard - but
341     it does no harm).
342    
343     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
344     most of the places where whitespace preceded '#'. I have given up and
345     allowed the remaining 2 cases to be at the margin.
346    
347     + Rename some variables in pcre to eliminate shadowing. This seems very
348     pedantic, but does no harm, of course.
349    
350     6. Moved the call to setjmp() into its own function, to get rid of warnings
351     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
352    
353     7. Constructs such as \d{8,} were compiling into the equivalent of
354 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
355 nigel 9 outcome, but in this particular case used more store than had been allocated,
356     which caused the bug to be discovered because it threw up an internal error.
357    
358     8. The debugging code in both pcre and pcretest for outputting the compiled
359     form of a regex was going wrong in the case of back references followed by
360     curly-bracketed repeats.
361    
362    
363 nigel 7 Version 1.02 12-Dec-97
364     ----------------------
365    
366     1. Typos in pcre.3 and comments in the source fixed.
367    
368     2. Applied a contributed patch to get rid of places where it used to remove
369     'const' from variables, and fixed some signed/unsigned and uninitialized
370     variable warnings.
371    
372     3. Added the "runtest" target to Makefile.
373    
374     4. Set default compiler flag to -O2 rather than just -O.
375    
376    
377 nigel 5 Version 1.01 19-Nov-97
378     ----------------------
379    
380     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
381     like /([ab]*)*/, that is, for classes with more than one character in them.
382    
383     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
384     as /((?>a*))*/ (a PCRE_EXTRA facility).
385    
386    
387     Version 1.00 18-Nov-97
388     ----------------------
389    
390     1. Added compile-time macros to support systems such as SunOS4 which don't have
391     memmove() or strerror() but have other things that can be used instead.
392    
393     2. Arranged that "make clean" removes the executables.
394    
395    
396 nigel 3 Version 0.99 27-Oct-97
397     ----------------------
398    
399     1. Fixed bug in code for optimizing classes with only one character. It was
400     initializing a 32-byte map regardless, which could cause it to run off the end
401     of the memory it had got.
402    
403     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
404    
405    
406     Version 0.98 22-Oct-97
407     ----------------------
408    
409     1. Fixed bug in code for handling temporary memory usage when there are more
410     back references than supplied space in the ovector. This could cause segfaults.
411    
412    
413     Version 0.97 21-Oct-97
414     ----------------------
415    
416     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
417    
418     2. Optimized negated single characters not to use a bit map.
419    
420     3. Brought error texts together as macro definitions; clarified some of them;
421     fixed one that was wrong - it said "range out of order" when it meant "invalid
422     escape sequence".
423    
424     4. Changed some char * arguments to const char *.
425    
426     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
427    
428     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
429     pcretest.
430    
431    
432     Version 0.96 16-Oct-97
433     ----------------------
434    
435     1. Added a simple "pgrep" utility to the distribution.
436    
437     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
438     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
439     where "ddd" means "one or more decimal digits".
440    
441     3. Fixed serious bug. If a pattern had a back reference, but the call to
442     pcre_exec() didn't supply a large enough ovector to record the related
443     identifying subpattern, the match always failed. PCRE now remembers the number
444     of the largest back reference, and gets some temporary memory in which to save
445     the offsets during matching if necessary, in order to ensure that
446     backreferences always work.
447    
448     4. Increased the compatibility with Perl in a number of ways:
449    
450     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
451     to request this handling. The option can be set at compile or exec time.
452    
453     (b) $ matches before a terminating newline by default; an option
454     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
455     mode). The option can be set at compile or exec time.
456    
457     (c) The handling of \ followed by a digit other than 0 is now supposed to be
458     the same as Perl's. If the decimal number it represents is less than 10
459     or there aren't that many previous left capturing parentheses, an octal
460     escape is read. Inside a character class, it's always an octal escape,
461     even if it is a single digit.
462    
463     (d) An escaped but undefined alphabetic character is taken as a literal,
464     unless PCRE_EXTRA is set. Currently this just reserves the remaining
465     escapes.
466    
467     (e) {0} is now permitted. (The previous item is removed from the compiled
468     pattern).
469    
470     5. Changed all the names of code files so that the basic parts are no longer
471     than 10 characters, and abolished the teeny "globals.c" file.
472    
473     6. Changed the handling of character classes; they are now done with a 32-byte
474     bit map always.
475    
476     7. Added the -d and /D options to pcretest to make it possible to look at the
477     internals of compilation without having to recompile pcre.
478    
479    
480     Version 0.95 23-Sep-97
481     ----------------------
482    
483     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
484     \x20 at the start of a run of normal characters. These were being treated as
485     real characters, instead of the source characters being re-checked.
486    
487    
488     Version 0.94 18-Sep-97
489     ----------------------
490    
491     1. The functions are now thread-safe, with the caveat that the global variables
492     containing pointers to malloc() and free() or alternative functions are the
493     same for all threads.
494    
495     2. Get pcre_study() to generate a bitmap of initial characters for non-
496     anchored patterns when this is possible, and use it if passed to pcre_exec().
497    
498    
499     Version 0.93 15-Sep-97
500     ----------------------
501    
502     1. /(b)|(:+)/ was computing an incorrect first character.
503    
504     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
505     but not actually doing anything yet.
506    
507     3. Treat "-" characters in classes that cannot be part of ranges as literals,
508     as Perl does (e.g. [-az] or [az-]).
509    
510     4. Set the anchored flag if a branch starts with .* or .*? because that tests
511     all possible positions.
512    
513     5. Split up into different modules to avoid including unneeded functions in a
514     compiled binary. However, compile and exec are still in one module. The "study"
515     function is split off.
516    
517     6. The character tables are now in a separate module whose source is generated
518     by an auxiliary program - but can then be edited by hand if required. There are
519     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
520     toupper() in the code.
521    
522     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
523     make them global. Abolish the function for setting them, as the caller can now
524     set them directly.
525    
526    
527     Version 0.92 11-Sep-97
528     ----------------------
529    
530     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
531     (e.g. /a{1,3}/) was broken (I mis-optimized it).
532    
533     2. Caseless matching was not working in character classes if the characters in
534     the pattern were in upper case.
535    
536     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
537    
538     4. Make PCRE_ANCHORED public and accept as a compile option.
539    
540     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
541     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
542     pass them.
543    
544     6. Give an error if bad option bits passed at compile or run time.
545    
546     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
547     pcretest to cause it to pass that flag.
548    
549     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
550     options, and the first character, if set.
551    
552     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
553    
554    
555     Version 0.91 10-Sep-97
556     ----------------------
557    
558     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
559     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
560    
561     2. PCRE was looping on encountering an indefinitely repeated back reference to
562     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
563     Perl does - treats the match as successful.
564    
565     ****

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