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Revision 41 - (hide annotations) (download)
Sat Feb 24 21:39:17 2007 UTC (7 years, 4 months ago) by nigel
File size: 20293 byte(s)
Load pcre-2.08a into code/trunk.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 nigel 5
5 nigel 41 Version 2.09 14-Sep-99
6     ----------------------
7    
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    
27 nigel 39 Version 2.08 31-Aug-99
28     ----------------------
29    
30     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
31     trying to match at the startoffset position, but instead was moving forward to
32     the next newline as if a previous match had failed.
33    
34     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
35     and could get into a loop if a null string was matched other than at the start
36     of the subject.
37    
38     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
39     be distinguished at compile time, and for completeness also added PCRE_DATE.
40    
41     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
42     in GnuWin32 environments.
43    
44    
45 nigel 37 Version 2.07 29-Jul-99
46     ----------------------
47    
48     1. The documentation is now supplied in plain text form and HTML as well as in
49     the form of man page sources.
50    
51     2. C++ compilers don't like assigning (void *) values to other pointer types.
52     In particular this affects malloc(). Although there is no problem in Standard
53     C, I've put in casts to keep C++ compilers happy.
54    
55     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
56     should be (const char *).
57    
58     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
59     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
60     However, I haven't made this a standard facility. The documentation doesn't
61     mention it, and the Makefile doesn't support it.
62    
63     5. The Makefile now contains an "install" target, with editable destinations at
64     the top of the file. The pcretest program is not installed.
65    
66     6. pgrep -V now gives the PCRE version number and date.
67    
68     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
69     causing the entire string to be ignored, instead of just the last character.
70    
71     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
72     non-matching string, it can take a very, very long time, even for strings of
73     quite modest length, because of the nested recursion. PCRE now does better in
74     some of these cases. It does this by remembering the last required literal
75     character in the pattern, and pre-searching the subject to ensure it is present
76     before running the real match. In other words, it applies a heuristic to detect
77     some types of certain failure quickly, and in the above example, if presented
78     with a string that has no trailing " it gives "no match" very quickly.
79    
80     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
81     other alternatives are tried instead.
82    
83    
84 nigel 35 Version 2.06 09-Jun-99
85     ----------------------
86    
87     1. Change pcretest's output for amount of store used to show just the code
88     space, because the remainder (the data block) varies in size between 32-bit and
89     64-bit systems.
90    
91     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
92     start matching at. This allows lookbehinds to work when searching for multiple
93     occurrences in a string.
94    
95     3. Added additional options to pcretest for testing multiple occurrences:
96    
97     /+ outputs the rest of the string that follows a match
98     /g loops for multiple occurrences, using the new startoffset argument
99     /G loops for multiple occurrences by passing an incremented pointer
100    
101     4. PCRE wasn't doing the "first character" optimization for patterns starting
102     with \b or \B, though it was doing it for other lookbehind assertions. That is,
103     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
104     the letter 'x'. On long subject strings, this gives a significant speed-up.
105    
106    
107 nigel 33 Version 2.05 21-Apr-99
108     ----------------------
109    
110     1. Changed the type of magic_number from int to long int so that it works
111     properly on 16-bit systems.
112    
113     2. Fixed a bug which caused patterns starting with .* not to work correctly
114     when the subject string contained newline characters. PCRE was assuming
115     anchoring for such patterns in all cases, which is not correct because .* will
116     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
117     DOTALL is set at top level; otherwise it knows that patterns starting with .*
118     must be retried after every newline in the subject.
119    
120    
121 nigel 31 Version 2.04 18-Feb-99
122     ----------------------
123    
124     1. For parenthesized subpatterns with repeats whose minimum was zero, the
125     computation of the store needed to hold the pattern was incorrect (too large).
126     If such patterns were nested a few deep, this could multiply and become a real
127     problem.
128    
129     2. Added /M option to pcretest to show the memory requirement of a specific
130     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
131    
132     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
133     compiled in such a way that the backtracking after subsequent failure was
134     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
135     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
136    
137    
138 nigel 29 Version 2.03 02-Feb-99
139     ----------------------
140    
141     1. Fixed typo and small mistake in man page.
142    
143 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
144     LICENCE file containing the conditions.
145 nigel 29
146     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
147     Perl, that is the internal \ allows the delimiter to be included in the
148     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
149     the final delimiter, add \ to the end of the pattern (to test the error).
150    
151     4. Added the convenience functions for extracting substrings after a successful
152     match. Updated pcretest to make it able to test these functions.
153    
154    
155 nigel 27 Version 2.02 14-Jan-99
156     ----------------------
157    
158     1. Initialized the working variables associated with each extraction so that
159     their saving and restoring doesn't refer to uninitialized store.
160    
161     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
162     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
163     fix the problem.
164    
165     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
166     calls, and wasn't printing the correct value for compiling calls. Increased the
167     default value of LOOPREPEAT, and the number of significant figures in the
168     times.
169    
170     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
171    
172     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
173     a building problem on Windows NT with a FAT file system.
174    
175    
176 nigel 25 Version 2.01 21-Oct-98
177     ----------------------
178    
179     1. Changed the API for pcre_compile() to allow for the provision of a pointer
180     to character tables built by pcre_maketables() in the current locale. If NULL
181     is passed, the default tables are used.
182    
183    
184 nigel 23 Version 2.00 24-Sep-98
185 nigel 21 ----------------------
186    
187 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
188     it any more.
189    
190     2. Allow quantification of (?>) groups, and make it work correctly.
191    
192     3. The first character computation wasn't working for (?>) groups.
193    
194     4. Correct the implementation of \Z (it is permitted to match on the \n at the
195     end of the subject) and add 5.005's \z, which really does match only at the
196     very end of the subject.
197    
198     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
199    
200     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
201     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
202     localized options. All options to pcre_study() were also removed.
203    
204     7. Add other new features from 5.005:
205    
206     $(?<= positive lookbehind
207     $(?<! negative lookbehind
208     (?imsx-imsx) added the unsetting capability
209     such a setting is global if at outer level; local otherwise
210     (?imsx-imsx:) non-capturing groups with option setting
211     (?(cond)re|re) conditional pattern matching
212    
213     A backreference to itself in a repeated group matches the previous
214     captured string.
215    
216     8. General tidying up of studying (both automatic and via "study")
217     consequential on the addition of new assertions.
218    
219     9. As in 5.005, unlimited repeated groups that could match an empty substring
220     are no longer faulted at compile time. Instead, the loop is forcibly broken at
221     runtime if any iteration does actually match an empty substring.
222    
223     10. Include the RunTest script in the distribution.
224    
225     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
226     discrepancies, some of which were old and were also with respect to 5.004. They
227     have now been fixed.
228    
229    
230     Version 1.09 28-Apr-98
231     ----------------------
232    
233 nigel 21 1. A negated single character class followed by a quantifier with a minimum
234     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
235     program crashes, or just wrong answers. This did not apply to negated classes
236     containing more than one character, or to minima other than one.
237    
238    
239 nigel 19 Version 1.08 27-Mar-98
240     ----------------------
241    
242     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
243    
244     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
245     latter must appear before anything that relies on it in the pattern.
246    
247    
248 nigel 17 Version 1.07 16-Feb-98
249     ----------------------
250    
251     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
252     repeat of a potentially empty string).
253    
254    
255 nigel 15 Version 1.06 23-Jan-98
256     ----------------------
257    
258     1. Added Markus Oberhumer's little patches for C++.
259    
260     2. Literal strings longer than 255 characters were broken.
261    
262    
263 nigel 13 Version 1.05 23-Dec-97
264     ----------------------
265    
266     1. Negated character classes containing more than one character were failing if
267     PCRE_CASELESS was set at run time.
268    
269    
270 nigel 11 Version 1.04 19-Dec-97
271     ----------------------
272    
273     1. Corrected the man page, where some "const" qualifiers had been omitted.
274    
275     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
276     input syntax.
277    
278     3. Fixed memory leak which occurred when a regex with back references was
279     matched with an offsets vector that wasn't big enough. The temporary memory
280     that is used in this case wasn't being freed if the match failed.
281    
282     4. Tidied pcretest to ensure it frees memory that it gets.
283    
284     5. Temporary memory was being obtained in the case where the passed offsets
285     vector was exactly big enough.
286    
287     6. Corrected definition of offsetof() from change 5 below.
288    
289     7. I had screwed up change 6 below and broken the rules for the use of
290     setjmp(). Now fixed.
291    
292    
293 nigel 9 Version 1.03 18-Dec-97
294     ----------------------
295    
296     1. A erroneous regex with a missing opening parenthesis was correctly
297     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
298     on some systems.
299    
300     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
301     it was reported that one broken compiler failed on the former because "code" is
302     also an independent variable.
303    
304     3. The erroneous regex a[]b caused an array overrun reference.
305    
306     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
307     fail on data ending with that character. (It was going on too far, and checking
308     the next character, typically a binary zero.) This was specific to the
309     optimized code for single-character negative classes.
310    
311     5. Added a contributed patch from the TIN world which does the following:
312    
313     + Add an undef for memmove, in case the the system defines a macro for it.
314    
315     + Add a definition of offsetof(), in case there isn't one. (I don't know
316     the reason behind this - offsetof() is part of the ANSI standard - but
317     it does no harm).
318    
319     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
320     most of the places where whitespace preceded '#'. I have given up and
321     allowed the remaining 2 cases to be at the margin.
322    
323     + Rename some variables in pcre to eliminate shadowing. This seems very
324     pedantic, but does no harm, of course.
325    
326     6. Moved the call to setjmp() into its own function, to get rid of warnings
327     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
328    
329     7. Constructs such as \d{8,} were compiling into the equivalent of
330 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
331 nigel 9 outcome, but in this particular case used more store than had been allocated,
332     which caused the bug to be discovered because it threw up an internal error.
333    
334     8. The debugging code in both pcre and pcretest for outputting the compiled
335     form of a regex was going wrong in the case of back references followed by
336     curly-bracketed repeats.
337    
338    
339 nigel 7 Version 1.02 12-Dec-97
340     ----------------------
341    
342     1. Typos in pcre.3 and comments in the source fixed.
343    
344     2. Applied a contributed patch to get rid of places where it used to remove
345     'const' from variables, and fixed some signed/unsigned and uninitialized
346     variable warnings.
347    
348     3. Added the "runtest" target to Makefile.
349    
350     4. Set default compiler flag to -O2 rather than just -O.
351    
352    
353 nigel 5 Version 1.01 19-Nov-97
354     ----------------------
355    
356     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
357     like /([ab]*)*/, that is, for classes with more than one character in them.
358    
359     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
360     as /((?>a*))*/ (a PCRE_EXTRA facility).
361    
362    
363     Version 1.00 18-Nov-97
364     ----------------------
365    
366     1. Added compile-time macros to support systems such as SunOS4 which don't have
367     memmove() or strerror() but have other things that can be used instead.
368    
369     2. Arranged that "make clean" removes the executables.
370    
371    
372 nigel 3 Version 0.99 27-Oct-97
373     ----------------------
374    
375     1. Fixed bug in code for optimizing classes with only one character. It was
376     initializing a 32-byte map regardless, which could cause it to run off the end
377     of the memory it had got.
378    
379     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
380    
381    
382     Version 0.98 22-Oct-97
383     ----------------------
384    
385     1. Fixed bug in code for handling temporary memory usage when there are more
386     back references than supplied space in the ovector. This could cause segfaults.
387    
388    
389     Version 0.97 21-Oct-97
390     ----------------------
391    
392     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
393    
394     2. Optimized negated single characters not to use a bit map.
395    
396     3. Brought error texts together as macro definitions; clarified some of them;
397     fixed one that was wrong - it said "range out of order" when it meant "invalid
398     escape sequence".
399    
400     4. Changed some char * arguments to const char *.
401    
402     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
403    
404     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
405     pcretest.
406    
407    
408     Version 0.96 16-Oct-97
409     ----------------------
410    
411     1. Added a simple "pgrep" utility to the distribution.
412    
413     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
414     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
415     where "ddd" means "one or more decimal digits".
416    
417     3. Fixed serious bug. If a pattern had a back reference, but the call to
418     pcre_exec() didn't supply a large enough ovector to record the related
419     identifying subpattern, the match always failed. PCRE now remembers the number
420     of the largest back reference, and gets some temporary memory in which to save
421     the offsets during matching if necessary, in order to ensure that
422     backreferences always work.
423    
424     4. Increased the compatibility with Perl in a number of ways:
425    
426     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
427     to request this handling. The option can be set at compile or exec time.
428    
429     (b) $ matches before a terminating newline by default; an option
430     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
431     mode). The option can be set at compile or exec time.
432    
433     (c) The handling of \ followed by a digit other than 0 is now supposed to be
434     the same as Perl's. If the decimal number it represents is less than 10
435     or there aren't that many previous left capturing parentheses, an octal
436     escape is read. Inside a character class, it's always an octal escape,
437     even if it is a single digit.
438    
439     (d) An escaped but undefined alphabetic character is taken as a literal,
440     unless PCRE_EXTRA is set. Currently this just reserves the remaining
441     escapes.
442    
443     (e) {0} is now permitted. (The previous item is removed from the compiled
444     pattern).
445    
446     5. Changed all the names of code files so that the basic parts are no longer
447     than 10 characters, and abolished the teeny "globals.c" file.
448    
449     6. Changed the handling of character classes; they are now done with a 32-byte
450     bit map always.
451    
452     7. Added the -d and /D options to pcretest to make it possible to look at the
453     internals of compilation without having to recompile pcre.
454    
455    
456     Version 0.95 23-Sep-97
457     ----------------------
458    
459     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
460     \x20 at the start of a run of normal characters. These were being treated as
461     real characters, instead of the source characters being re-checked.
462    
463    
464     Version 0.94 18-Sep-97
465     ----------------------
466    
467     1. The functions are now thread-safe, with the caveat that the global variables
468     containing pointers to malloc() and free() or alternative functions are the
469     same for all threads.
470    
471     2. Get pcre_study() to generate a bitmap of initial characters for non-
472     anchored patterns when this is possible, and use it if passed to pcre_exec().
473    
474    
475     Version 0.93 15-Sep-97
476     ----------------------
477    
478     1. /(b)|(:+)/ was computing an incorrect first character.
479    
480     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
481     but not actually doing anything yet.
482    
483     3. Treat "-" characters in classes that cannot be part of ranges as literals,
484     as Perl does (e.g. [-az] or [az-]).
485    
486     4. Set the anchored flag if a branch starts with .* or .*? because that tests
487     all possible positions.
488    
489     5. Split up into different modules to avoid including unneeded functions in a
490     compiled binary. However, compile and exec are still in one module. The "study"
491     function is split off.
492    
493     6. The character tables are now in a separate module whose source is generated
494     by an auxiliary program - but can then be edited by hand if required. There are
495     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
496     toupper() in the code.
497    
498     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
499     make them global. Abolish the function for setting them, as the caller can now
500     set them directly.
501    
502    
503     Version 0.92 11-Sep-97
504     ----------------------
505    
506     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
507     (e.g. /a{1,3}/) was broken (I mis-optimized it).
508    
509     2. Caseless matching was not working in character classes if the characters in
510     the pattern were in upper case.
511    
512     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
513    
514     4. Make PCRE_ANCHORED public and accept as a compile option.
515    
516     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
517     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
518     pass them.
519    
520     6. Give an error if bad option bits passed at compile or run time.
521    
522     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
523     pcretest to cause it to pass that flag.
524    
525     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
526     options, and the first character, if set.
527    
528     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
529    
530    
531     Version 0.91 10-Sep-97
532     ----------------------
533    
534     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
535     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
536    
537     2. PCRE was looping on encountering an indefinitely repeated back reference to
538     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
539     Perl does - treats the match as successful.
540    
541     ****

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