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

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