Contents of /code/trunk/ChangeLog

ChangeLog for PCRE
------------------


Version 1.01 19-Nov-97
----------------------

1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
like /([ab]*)*/, that is, for classes with more than one character in them.

2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
as /((?>a*))*/ (a PCRE_EXTRA facility).


Version 1.00 18-Nov-97
----------------------

1. Added compile-time macros to support systems such as SunOS4 which don't have
memmove() or strerror() but have other things that can be used instead.

2. Arranged that "make clean" removes the executables.


Version 0.99 27-Oct-97
----------------------

1. Fixed bug in code for optimizing classes with only one character. It was
initializing a 32-byte map regardless, which could cause it to run off the end
of the memory it had got.

2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.


Version 0.98 22-Oct-97
----------------------

1. Fixed bug in code for handling temporary memory usage when there are more
back references than supplied space in the ovector. This could cause segfaults.


Version 0.97 21-Oct-97
----------------------

1. Added the \X "cut" facility, conditional on PCRE_EXTRA.

2. Optimized negated single characters not to use a bit map.

3. Brought error texts together as macro definitions; clarified some of them;
fixed one that was wrong - it said "range out of order" when it meant "invalid
escape sequence".

4. Changed some char * arguments to const char *.

5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).

6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
pcretest.


Version 0.96 16-Oct-97
----------------------

1. Added a simple "pgrep" utility to the distribution.

2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
where "ddd" means "one or more decimal digits".

3. Fixed serious bug. If a pattern had a back reference, but the call to
pcre_exec() didn't supply a large enough ovector to record the related
identifying subpattern, the match always failed. PCRE now remembers the number
of the largest back reference, and gets some temporary memory in which to save
the offsets during matching if necessary, in order to ensure that
backreferences always work.

4. Increased the compatibility with Perl in a number of ways:

  (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
      to request this handling. The option can be set at compile or exec time.

  (b) $ matches before a terminating newline by default; an option
      PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
      mode). The option can be set at compile or exec time.

  (c) The handling of \ followed by a digit other than 0 is now supposed to be
      the same as Perl's. If the decimal number it represents is less than 10
      or there aren't that many previous left capturing parentheses, an octal
      escape is read. Inside a character class, it's always an octal escape,
      even if it is a single digit.

  (d) An escaped but undefined alphabetic character is taken as a literal,
      unless PCRE_EXTRA is set. Currently this just reserves the remaining
      escapes.

  (e) {0} is now permitted. (The previous item is removed from the compiled
      pattern).

5. Changed all the names of code files so that the basic parts are no longer
than 10 characters, and abolished the teeny "globals.c" file.

6. Changed the handling of character classes; they are now done with a 32-byte
bit map always.

7. Added the -d and /D options to pcretest to make it possible to look at the
internals of compilation without having to recompile pcre.


Version 0.95 23-Sep-97
----------------------

1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
\x20 at the start of a run of normal characters. These were being treated as
real characters, instead of the source characters being re-checked.


Version 0.94 18-Sep-97
----------------------

1. The functions are now thread-safe, with the caveat that the global variables
containing pointers to malloc() and free() or alternative functions are the
same for all threads.

2. Get pcre_study() to generate a bitmap of initial characters for non-
anchored patterns when this is possible, and use it if passed to pcre_exec().


Version 0.93 15-Sep-97
----------------------

1. /(b)|(:+)/ was computing an incorrect first character.

2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
but not actually doing anything yet.

3. Treat "-" characters in classes that cannot be part of ranges as literals,
as Perl does (e.g. [-az] or [az-]).

4. Set the anchored flag if a branch starts with .* or .*? because that tests
all possible positions.

5. Split up into different modules to avoid including unneeded functions in a
compiled binary. However, compile and exec are still in one module. The "study"
function is split off.

6. The character tables are now in a separate module whose source is generated
by an auxiliary program - but can then be edited by hand if required. There are
now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
toupper() in the code.

7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
make them global. Abolish the function for setting them, as the caller can now
set them directly.


Version 0.92 11-Sep-97
----------------------

1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
(e.g. /a{1,3}/) was broken (I mis-optimized it).

2. Caseless matching was not working in character classes if the characters in
the pattern were in upper case.

3. Make ranges like [W-c] work in the same way as Perl for caseless matching.

4. Make PCRE_ANCHORED public and accept as a compile option.

5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
pass them.

6. Give an error if bad option bits passed at compile or run time.

7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
pcretest to cause it to pass that flag.

8. Add pcre_info(), to get the number of identifying subpatterns, the stored
options, and the first character, if set.

9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.


Version 0.91 10-Sep-97
----------------------

1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
match the empty string as in /(a*)*/. It was looping and ultimately crashing.

2. PCRE was looping on encountering an indefinitely repeated back reference to
a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
Perl does - treats the match as successful.

****
1	nigel	3	ChangeLog for PCRE
2			------------------
3
4	nigel	5
5			Version 1.01 19-Nov-97
6			----------------------
7
8			1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
9			like /([ab])/, that is, for classes with more than one character in them.
10
11			2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
12			as /((?>a))/ (a PCRE_EXTRA facility).
13
14
15			Version 1.00 18-Nov-97
16			----------------------
17
18			1. Added compile-time macros to support systems such as SunOS4 which don't have
19			memmove() or strerror() but have other things that can be used instead.
20
21			2. Arranged that "make clean" removes the executables.
22
23
24	nigel	3	Version 0.99 27-Oct-97
25			----------------------
26
27			1. Fixed bug in code for optimizing classes with only one character. It was
28			initializing a 32-byte map regardless, which could cause it to run off the end
29			of the memory it had got.
30
31			2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
32
33
34			Version 0.98 22-Oct-97
35			----------------------
36
37			1. Fixed bug in code for handling temporary memory usage when there are more
38			back references than supplied space in the ovector. This could cause segfaults.
39
40
41			Version 0.97 21-Oct-97
42			----------------------
43
44			1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
45
46			2. Optimized negated single characters not to use a bit map.
47
48			3. Brought error texts together as macro definitions; clarified some of them;
49			fixed one that was wrong - it said "range out of order" when it meant "invalid
50			escape sequence".
51
52			4. Changed some char * arguments to const char *.
53
54			5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
55
56			6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
57			pcretest.
58
59
60			Version 0.96 16-Oct-97
61			----------------------
62
63			1. Added a simple "pgrep" utility to the distribution.
64
65			2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
66			unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
67			where "ddd" means "one or more decimal digits".
68
69			3. Fixed serious bug. If a pattern had a back reference, but the call to
70			pcre_exec() didn't supply a large enough ovector to record the related
71			identifying subpattern, the match always failed. PCRE now remembers the number
72			of the largest back reference, and gets some temporary memory in which to save
73			the offsets during matching if necessary, in order to ensure that
74			backreferences always work.
75
76			4. Increased the compatibility with Perl in a number of ways:
77
78			(a) . no longer matches \n by default; an option PCRE_DOTALL is provided
79			to request this handling. The option can be set at compile or exec time.
80
81			(b) $ matches before a terminating newline by default; an option
82			PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
83			mode). The option can be set at compile or exec time.
84
85			(c) The handling of \ followed by a digit other than 0 is now supposed to be
86			the same as Perl's. If the decimal number it represents is less than 10
87			or there aren't that many previous left capturing parentheses, an octal
88			escape is read. Inside a character class, it's always an octal escape,
89			even if it is a single digit.
90
91			(d) An escaped but undefined alphabetic character is taken as a literal,
92			unless PCRE_EXTRA is set. Currently this just reserves the remaining
93			escapes.
94
95			(e) {0} is now permitted. (The previous item is removed from the compiled
96			pattern).
97
98			5. Changed all the names of code files so that the basic parts are no longer
99			than 10 characters, and abolished the teeny "globals.c" file.
100
101			6. Changed the handling of character classes; they are now done with a 32-byte
102			bit map always.
103
104			7. Added the -d and /D options to pcretest to make it possible to look at the
105			internals of compilation without having to recompile pcre.
106
107
108			Version 0.95 23-Sep-97
109			----------------------
110
111			1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
112			\x20 at the start of a run of normal characters. These were being treated as
113			real characters, instead of the source characters being re-checked.
114
115
116			Version 0.94 18-Sep-97
117			----------------------
118
119			1. The functions are now thread-safe, with the caveat that the global variables
120			containing pointers to malloc() and free() or alternative functions are the
121			same for all threads.
122
123			2. Get pcre_study() to generate a bitmap of initial characters for non-
124			anchored patterns when this is possible, and use it if passed to pcre_exec().
125
126
127			Version 0.93 15-Sep-97
128			----------------------
129
130			1. /(b)\|(:+)/ was computing an incorrect first character.
131
132			2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
133			but not actually doing anything yet.
134
135			3. Treat "-" characters in classes that cannot be part of ranges as literals,
136			as Perl does (e.g. [-az] or [az-]).
137
138			4. Set the anchored flag if a branch starts with .* or .*? because that tests
139			all possible positions.
140
141			5. Split up into different modules to avoid including unneeded functions in a
142			compiled binary. However, compile and exec are still in one module. The "study"
143			function is split off.
144
145			6. The character tables are now in a separate module whose source is generated
146			by an auxiliary program - but can then be edited by hand if required. There are
147			now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
148			toupper() in the code.
149
150			7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
151			make them global. Abolish the function for setting them, as the caller can now
152			set them directly.
153
154
155			Version 0.92 11-Sep-97
156			----------------------
157
158			1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
159			(e.g. /a{1,3}/) was broken (I mis-optimized it).
160
161			2. Caseless matching was not working in character classes if the characters in
162			the pattern were in upper case.
163
164			3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
165
166			4. Make PCRE_ANCHORED public and accept as a compile option.
167
168			5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
169			PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
170			pass them.
171
172			6. Give an error if bad option bits passed at compile or run time.
173
174			7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
175			pcretest to cause it to pass that flag.
176
177			8. Add pcre_info(), to get the number of identifying subpatterns, the stored
178			options, and the first character, if set.
179
180			9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
181
182
183			Version 0.91 10-Sep-97
184			----------------------
185
186			1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
187			match the empty string as in /(a)/. It was looping and ultimately crashing.
188
189			2. PCRE was looping on encountering an indefinitely repeated back reference to
190			a subpattern that had matched an empty string, e.g. /(a\|)\1*/. It now does what
191			Perl does - treats the match as successful.
192
193			****