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Load pcre-2.04 into code/trunk.

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

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