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ChangeLog for PCRE
Note that the PCRE 8.xx series (PCRE1) is now at end of life. All development
is happening in the PCRE2 10.xx series.
Version 8.45 15-June-2021
This is the final release of PCRE1. A few minor tidies are included.
1. CMakeLists.txt has two user-supplied patches applied, one to allow for the
setting of MODULE_PATH, and the other to support the generation of pcre-config
file and libpcre*.pc files.
2. There was a memory leak if a compile error occurred when there were more
than 20 named groups (Bugzilla #2613).
3. Fixed some typos in code and documentation.
4. Fixed a small (*MARK) bug in the interpreter (Bugzilla #2771).
Version 8.44 12 February-2020
1. Setting --enable-jit=auto for an out-of-tree build failed because the
source directory wasn't in the search path for AC_TRY_COMPILE always. Patch
from Ross Burton.
2. Applied a patch from Michael Shigorin to fix 8.43 build on e2k arch
with lcc compiler (EDG frontend based); the problem it fixes is:
lcc: "pcrecpp.cc", line 74: error: declaration aliased to undefined entity
"_ZN7pcrecpp2RE6no_argE" [-Werror]
3. Change 2 for 8.43 omitted (*LF) from the list of start-of-pattern items. Now
4. Fix ARMv5 JIT improper handling of labels right after a constant pool.
5. Small patch to pcreposix.c to set the erroroffset field to -1 immediately
after a successful compile, instead of at the start of matching to avoid a
sanitizer complaint (regexec is supposed to be thread safe).
6. Check the size of the number after (?C as it is read, in order to avoid
integer overflow.
7. Tidy up left shifts to avoid sanitize warnings; also fix one NULL deference
in pcretest.
Version 8.43 23-February-2019
1. Some time ago the config macro SUPPORT_UTF8 was changed to SUPPORT_UTF
because it also applies to UTF-16 and UTF-32. However, this change was not made
in the pcre2cpp files; consequently the C++ wrapper has from then been compiled
with a bug in it, which would have been picked up by the unit test except that
it also had its UTF8 code cut out. The bug was in a global replace when moving
forward after matching an empty string.
2. The C++ wrapper got broken a long time ago (version 7.3, August 2007) when
(*CR) was invented (assuming it was the first such start-of-pattern option).
The wrapper could never handle such patterns because it wraps patterns in
(?:...)\z in order to support end anchoring. I have hacked in some code to fix
this, that is, move the wrapping till after any existing start-of-pattern
special settings.
3. "pcre2grep" (sic) was accidentally mentioned in an error message (fix was
ported from PCRE2).
4. Typo LCC_ALL for LC_ALL fixed in pcregrep.
5. In a pattern such as /[^\x{100}-\x{ffff}]*[\x80-\xff]/ which has a repeated
negative class with no characters less than 0x100 followed by a positive class
with only characters less than 0x100, the first class was incorrectly being
auto-possessified, causing incorrect match failures.
6. If the only branch in a conditional subpattern was anchored, the whole
subpattern was treated as anchored, when it should not have been, since the
assumed empty second branch cannot be anchored. Demonstrated by test patterns
such as /(?(1)^())b/ or /(?(?=^))b/.
7. Fix subject buffer overread in JIT when UTF is disabled and \X or \R has
a greater than 1 fixed quantifier. This issue was found by Yunho Kim.
8. If a pattern started with a subroutine call that had a quantifier with a
minimum of zero, an incorrect "match must start with this character" could be
recorded. Example: /(?&xxx)*ABC(?<xxx>XYZ)/ would (incorrectly) expect 'A' to
be the first character of a match.
9. Improve MAP_JIT flag usage on MacOS. Patch by Rich Siegel.
Version 8.42 20-March-2018
1. Fixed a MIPS issue in the JIT compiler reported by Joshua Kinard.
2. Fixed outdated real_pcre definitions in pcre.h.in (patch by Evgeny Kotkov).
3. pcregrep was truncating components of file names to 128 characters when
processing files with the -r option, and also (some very odd code) truncating
path names to 512 characters. There is now a check on the absolute length of
full path file names, which may be up to 2047 characters long.
4. Using pcre_dfa_exec(), in UTF mode when UCP support was not defined, there
was the possibility of a false positive match when caselessly matching a "not
this character" item such as [^\x{1234}] (with a code point greater than 127)
because the "other case" variable was not being initialized.
5. Although pcre_jit_exec checks whether the pattern is compiled
in a given mode, it was also expected that at least one mode is available.
This is fixed and pcre_jit_exec returns with PCRE_ERROR_JIT_BADOPTION
when the pattern is not optimized by JIT at all.
6. The line number and related variables such as match counts in pcregrep
were all int variables, causing overflow when files with more than 2147483647
lines were processed (assuming 32-bit ints). They have all been changed to
unsigned long ints.
7. If a backreference with a minimum repeat count of zero was first in a
pattern, apart from assertions, an incorrect first matching character could be
recorded. For example, for the pattern /(?=(a))\1?b/, "b" was incorrectly set
as the first character of a match.
8. Fix out-of-bounds read for partial matching of /./ against an empty string
when the newline type is CRLF.
9. When matching using the the REG_STARTEND feature of the POSIX API with a
non-zero starting offset, unset capturing groups with lower numbers than a
group that did capture something were not being correctly returned as "unset"
(that is, with offset values of -1).
10. Matching the pattern /(*UTF)\C[^\v]+\x80/ against an 8-bit string
containing multi-code-unit characters caused bad behaviour and possibly a
crash. This issue was fixed for other kinds of repeat in release 8.37 by change
38, but repeating character classes were overlooked.
11. A small fix to pcregrep to avoid compiler warnings for -Wformat-overflow=2.
12. Added --enable-jit=auto support to configure.ac.
13. Fix misleading error message in configure.ac.
Version 8.41 05-July-2017
1. Fixed typo in CMakeLists.txt (wrong number of arguments for
2. Issue 1 for 8.40 below was not correctly fixed. If pcregrep in multiline
mode with --only-matching matched several lines, it restarted scanning at the
next line instead of moving on to the end of the matched string, which can be
several lines after the start.
3. Fix a missing else in the JIT compiler reported by 'idaifish'.
4. A (?# style comment is now ignored between a basic quantifier and a
following '+' or '?' (example: /X+(?#comment)?Y/.
5. Avoid use of a potentially overflowing buffer in pcregrep (patch by Petr
6. Fuzzers have reported issues in pcretest. These are NOT serious (it is,
after all, just a test program). However, to stop the reports, some easy ones
are fixed:
(a) Check for values < 256 when calling isprint() in pcretest.
(b) Give an error for too big a number after \O.
7. In the 32-bit library in non-UTF mode, an attempt to find a Unicode
property for a character with a code point greater than 0x10ffff (the Unicode
maximum) caused a crash.
8. The alternative matching function, pcre_dfa_exec() misbehaved if it
encountered a character class with a possessive repeat, for example [a-f]{3}+.
9. When pcretest called pcre_copy_substring() in 32-bit mode, it set the buffer
length incorrectly, which could result in buffer overflow.
10. Remove redundant line of code (accidentally left in ages ago).
11. Applied C++ patch from Irfan Adilovic to guard 'using std::' directives
with namespace pcrecpp (Bugzilla #2084).
12. Remove a duplication typo in pcre_tables.c.
13. Fix returned offsets from regexec() when REG_STARTEND is used with a
starting offset greater than zero.
Version 8.40 11-January-2017
1. Using -o with -M in pcregrep could cause unnecessary repeated output when
the match extended over a line boundary.
2. Applied Chris Wilson's second patch (Bugzilla #1681) to CMakeLists.txt for
MSVC static compilation, putting the first patch under a new option.
3. Fix register overwite in JIT when SSE2 acceleration is enabled.
4. Ignore "show all captures" (/=) for DFA matching.
5. Fix JIT unaligned accesses on x86. Patch by Marc Mutz.
6. In any wide-character mode (8-bit UTF or any 16-bit or 32-bit mode),
without PCRE_UCP set, a negative character type such as \D in a positive
class should cause all characters greater than 255 to match, whatever else
is in the class. There was a bug that caused this not to happen if a
Unicode property item was added to such a class, for example [\D\P{Nd}] or
7. When pcretest was outputing information from a callout, the caret indicator
for the current position in the subject line was incorrect if it was after
an escape sequence for a character whose code point was greater than
8. A pattern such as (?<RA>abc)(?(R)xyz) was incorrectly compiled such that
the conditional was interpreted as a reference to capturing group 1 instead
of a test for recursion. Any group whose name began with R was
misinterpreted in this way. (The reference interpretation should only
happen if the group's name is precisely "R".)
9. A number of bugs have been mended relating to match start-up optimizations
when the first thing in a pattern is a positive lookahead. These all
applied only when PCRE_NO_START_OPTIMIZE was *not* set:
(a) A pattern such as (?=.*X)X$ was incorrectly optimized as if it needed
both an initial 'X' and a following 'X'.
(b) Some patterns starting with an assertion that started with .* were
incorrectly optimized as having to match at the start of the subject or
after a newline. There are cases where this is not true, for example,
(?=.*[A-Z])(?=.{8,16})(?!.*[\s]) matches after the start in lines that
start with spaces. Starting .* in an assertion is no longer taken as an
indication of matching at the start (or after a newline).
Version 8.39 14-June-2016
1. If PCRE_AUTO_CALLOUT was set on a pattern that had a (?# comment between
an item and its qualifier (for example, A(?#comment)?B) pcre_compile()
misbehaved. This bug was found by the LLVM fuzzer.
2. Similar to the above, if an isolated \E was present between an item and its
qualifier when PCRE_AUTO_CALLOUT was set, pcre_compile() misbehaved. This
bug was found by the LLVM fuzzer.
3. Further to 8.38/46, negated classes such as [^[:^ascii:]\d] were also not
working correctly in UCP mode.
4. The POSIX wrapper function regexec() crashed if the option REG_STARTEND
was set when the pmatch argument was NULL. It now returns REG_INVARG.
5. Allow for up to 32-bit numbers in the ordin() function in pcregrep.
6. An empty \Q\E sequence between an item and its qualifier caused
pcre_compile() to misbehave when auto callouts were enabled. This bug was
found by the LLVM fuzzer.
7. If a pattern that was compiled with PCRE_EXTENDED started with white
space or a #-type comment that was followed by (?-x), which turns off
PCRE_EXTENDED, and there was no subsequent (?x) to turn it on again,
pcre_compile() assumed that (?-x) applied to the whole pattern and
consequently mis-compiled it. This bug was found by the LLVM fuzzer.
8. A call of pcre_copy_named_substring() for a named substring whose number
was greater than the space in the ovector could cause a crash.
9. Yet another buffer overflow bug involved duplicate named groups with a
group that reset capture numbers (compare 8.38/7 below). Once again, I have
just allowed for more memory, even if not needed. (A proper fix is
implemented in PCRE2, but it involves a lot of refactoring.)
10. pcre_get_substring_list() crashed if the use of \K in a match caused the
start of the match to be earlier than the end.
11. Migrating appropriate PCRE2 JIT improvements to PCRE.
12. A pattern such as /(?<=((?C)0))/, which has a callout inside a lookbehind
assertion, caused pcretest to generate incorrect output, and also to read
uninitialized memory (detected by ASAN or valgrind).
13. A pattern that included (*ACCEPT) in the middle of a sufficiently deeply
nested set of parentheses of sufficient size caused an overflow of the
compiling workspace (which was diagnosed, but of course is not desirable).
14. And yet another buffer overflow bug involving duplicate named groups, this
time nested, with a nested back reference. Yet again, I have just allowed
for more memory, because anything more needs all the refactoring that has
been done for PCRE2. An example pattern that provoked this bug is:
/((?J)(?'R'(?'R'(?'R'(?'R'(?'R'(?|(\k'R'))))))))/ and the bug was
registered as CVE-2016-1283.
15. pcretest went into a loop if global matching was requested with an ovector
size less than 2. It now gives an error message. This bug was found by
16. An invalid pattern fragment such as (?(?C)0 was not diagnosing an error
("assertion expected") when (?(?C) was not followed by an opening
17. Fixed typo ("&&" for "&") in pcre_study(). Fortunately, this could not
actually affect anything, by sheer luck.
18. Applied Chris Wilson's patch (Bugzilla #1681) to CMakeLists.txt for MSVC
static compilation.
19. Modified the RunTest script to incorporate a valgrind suppressions file so
that certain errors, provoked by the SSE2 instruction set when JIT is used,
are ignored.
20. A racing condition is fixed in JIT reported by Mozilla.
21. Minor code refactor to avoid "array subscript is below array bounds"
compiler warning.
22. Minor code refactor to avoid "left shift of negative number" warning.
23. Fix typo causing compile error when 16- or 32-bit JIT is compiled without
UCP support.
24. Refactor to avoid compiler warnings in pcrecpp.cc.
25. Refactor to fix a typo in pcre_jit_test.c
26. Patch to support compiling pcrecpp.cc with Intel compiler.
Version 8.38 23-November-2015
1. If a group that contained a recursive back reference also contained a
forward reference subroutine call followed by a non-forward-reference
subroutine call, for example /.((?2)(?R)\1)()/, pcre_compile() failed to
compile correct code, leading to undefined behaviour or an internally
detected error. This bug was discovered by the LLVM fuzzer.
2. Quantification of certain items (e.g. atomic back references) could cause
incorrect code to be compiled when recursive forward references were
involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
This bug was discovered by the LLVM fuzzer.
3. A repeated conditional group whose condition was a reference by name caused
a buffer overflow if there was more than one group with the given name.
This bug was discovered by the LLVM fuzzer.
4. A recursive back reference by name within a group that had the same name as
another group caused a buffer overflow. For example:
/(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
5. A forward reference by name to a group whose number is the same as the
current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
a buffer overflow at compile time. This bug was discovered by the LLVM
6. A lookbehind assertion within a set of mutually recursive subpatterns could
provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
7. Another buffer overflow bug involved duplicate named groups with a
reference between their definition, with a group that reset capture
numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
fixed by always allowing for more memory, even if not needed. (A proper fix
is implemented in PCRE2, but it involves more refactoring.)
8. There was no check for integer overflow in subroutine calls such as (?123).
9. The table entry for \l in EBCDIC environments was incorrect, leading to its
being treated as a literal 'l' instead of causing an error.
10. There was a buffer overflow if pcre_exec() was called with an ovector of
size 1. This bug was found by american fuzzy lop.
11. If a non-capturing group containing a conditional group that could match
an empty string was repeated, it was not identified as matching an empty
string itself. For example: /^(?:(?(1)x|)+)+$()/.
12. In an EBCDIC environment, pcretest was mishandling the escape sequences
\a and \e in test subject lines.
13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
instead of the EBCDIC value.
14. The handling of \c in an EBCDIC environment has been revised so that it is
now compatible with the specification in Perl's perlebcdic page.
15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
ASCII/Unicode. This has now been added to the list of characters that are
recognized as white space in EBCDIC.
16. When PCRE was compiled without UCP support, the use of \p and \P gave an
error (correctly) when used outside a class, but did not give an error
within a class.
17. \h within a class was incorrectly compiled in EBCDIC environments.
18. A pattern with an unmatched closing parenthesis that contained a backward
assertion which itself contained a forward reference caused buffer
overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
19. JIT should return with error when the compiled pattern requires more stack
space than the maximum.
20. A possessively repeated conditional group that could match an empty string,
for example, /(?(R))*+/, was incorrectly compiled.
21. Fix infinite recursion in the JIT compiler when certain patterns such as
/(?:|a|){100}x/ are analysed.
22. Some patterns with character classes involving [: and \\ were incorrectly
compiled and could cause reading from uninitialized memory or an incorrect
error diagnosis.
23. Pathological patterns containing many nested occurrences of [: caused
pcre_compile() to run for a very long time.
24. A conditional group with only one branch has an implicit empty alternative
branch and must therefore be treated as potentially matching an empty
25. If (?R was followed by - or + incorrect behaviour happened instead of a
26. Arrange to give up on finding the minimum matching length for overly
complex patterns.
27. Similar to (4) above: in a pattern with duplicated named groups and an
occurrence of (?| it is possible for an apparently non-recursive back
reference to become recursive if a later named group with the relevant
number is encountered. This could lead to a buffer overflow. Wen Guanxing
from Venustech ADLAB discovered this bug.
28. If pcregrep was given the -q option with -c or -l, or when handling a
binary file, it incorrectly wrote output to stdout.
29. The JIT compiler did not restore the control verb head in case of *THEN
control verbs. This issue was found by Karl Skomski with a custom LLVM
30. Error messages for syntax errors following \g and \k were giving inaccurate
offsets in the pattern.
31. Added a check for integer overflow in conditions (?(<digits>) and
(?(R<digits>). This omission was discovered by Karl Skomski with the LLVM
32. Handling recursive references such as (?2) when the reference is to a group
later in the pattern uses code that is very hacked about and error-prone.
It has been re-written for PCRE2. Here in PCRE1, a check has been added to
give an internal error if it is obvious that compiling has gone wrong.
33. The JIT compiler should not check repeats after a {0,1} repeat byte code.
This issue was found by Karl Skomski with a custom LLVM fuzzer.
34. The JIT compiler should restore the control chain for empty possessive
repeats. This issue was found by Karl Skomski with a custom LLVM fuzzer.
35. Match limit check added to JIT recursion. This issue was found by Karl
Skomski with a custom LLVM fuzzer.
36. Yet another case similar to 27 above has been circumvented by an
unconditional allocation of extra memory. This issue is fixed "properly" in
PCRE2 by refactoring the way references are handled. Wen Guanxing
from Venustech ADLAB discovered this bug.
37. Fix two assertion fails in JIT. These issues were found by Karl Skomski
with a custom LLVM fuzzer.
38. Fixed a corner case of range optimization in JIT.
39. An incorrect error "overran compiling workspace" was given if there were
exactly enough group forward references such that the last one extended
into the workspace safety margin. The next one would have expanded the
workspace. The test for overflow was not including the safety margin.
40. A match limit issue is fixed in JIT which was found by Karl Skomski
with a custom LLVM fuzzer.
41. Remove the use of /dev/null in testdata/testinput2, because it doesn't
work under Windows. (Why has it taken so long for anyone to notice?)
42. In a character class such as [\W\p{Any}] where both a negative-type escape
("not a word character") and a property escape were present, the property
escape was being ignored.
43. Fix crash caused by very long (*MARK) or (*THEN) names.
44. A sequence such as [[:punct:]b] that is, a POSIX character class followed
by a single ASCII character in a class item, was incorrectly compiled in
UCP mode. The POSIX class got lost, but only if the single character
followed it.
45. [:punct:] in UCP mode was matching some characters in the range 128-255
that should not have been matched.
46. If [:^ascii:] or [:^xdigit:] or [:^cntrl:] are present in a non-negated
class, all characters with code points greater than 255 are in the class.
When a Unicode property was also in the class (if PCRE_UCP is set, escapes
such as \w are turned into Unicode properties), wide characters were not
correctly handled, and could fail to match.
Version 8.37 28-April-2015
1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
for those parentheses to be closed with whatever has been captured so far.
However, it was failing to mark any other groups between the hightest
capture so far and the currrent group as "unset". Thus, the ovector for
those groups contained whatever was previously there. An example is the
pattern /(x)|((*ACCEPT))/ when matched against "abcd".
2. If an assertion condition was quantified with a minimum of zero (an odd
thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
unrecognized modifier, a crash could occur.
4. An attempt to do global matching in pcretest with a zero-length ovector
caused a crash.
5. Fixed a memory leak during matching that could occur for a subpattern
subroutine call (recursive or otherwise) if the number of captured groups
that had to be saved was greater than ten.
6. Catch a bad opcode during auto-possessification after compiling a bad UTF
string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
UTF with NO_UTF_CHECK is documented as having an undefined outcome.
7. A UTF pattern containing a "not" match of a non-ASCII character and a
subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
8. When a pattern is compiled, it remembers the highest back reference so that
when matching, if the ovector is too small, extra memory can be obtained to
use instead. A conditional subpattern whose condition is a check on a
capture having happened, such as, for example in the pattern
/^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
setting the highest backreference number. This mattered only if pcre_exec()
was called with an ovector that was too small to hold the capture, and there
was no other kind of back reference (a situation which is probably quite
rare). The effect of the bug was that the condition was always treated as
FALSE when the capture could not be consulted, leading to a incorrect
behaviour by pcre_exec(). This bug has been fixed.
9. A reference to a duplicated named group (either a back reference or a test
for being set in a conditional) that occurred in a part of the pattern where
PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
to be incorrectly calculated, leading to overwriting.
10. A mutually recursive set of back references such as (\2)(\1) caused a
segfault at study time (while trying to find the minimum matching length).
The infinite loop is now broken (with the minimum length unset, that is,
11. If an assertion that was used as a condition was quantified with a minimum
of zero, matching went wrong. In particular, if the whole group had
unlimited repetition and could match an empty string, a segfault was
likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
assertions to be quantified, but not if they are being used as conditions,
so the above pattern is faulted by Perl. PCRE has now been changed so that
it also rejects such patterns.
12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
failed to allow the zero-repeat case if pcre2_exec() was called with an
ovector too small to capture the group.
13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
Red Hat Product Security:
(a) A crash if /K and /F were both set with the option to save the compiled
(b) Another crash if the option to print captured substrings in a callout
was combined with setting a null ovector, for example \O\C+ as a subject
14. A pattern such as "((?2){0,1999}())?", which has a group containing a
forward reference repeated a large (but limited) number of times within a
repeated outer group that has a zero minimum quantifier, caused incorrect
code to be compiled, leading to the error "internal error:
previously-checked referenced subpattern not found" when an incorrect
memory address was read. This bug was reported as "heap overflow",
discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
call within a group that also contained a recursive back reference caused
incorrect code to be compiled. This bug was reported as "heap overflow",
discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
number CVE-2015-2326.
24. Computing the size of the JIT read-only data in advance has been a source
of various issues, and new ones are still appear unfortunately. To fix
existing and future issues, size computation is eliminated from the code,
and replaced by on-demand memory allocation.
25. A pattern such as /(?i)[A-`]/, where characters in the other case are
adjacent to the end of the range, and the range contained characters with
more than one other case, caused incorrect behaviour when compiled in UTF
mode. In that example, the range a-j was left out of the class.
26. Fix JIT compilation of conditional blocks, which assertion
is converted to (*FAIL). E.g: /(?(?!))/.
27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
discovered by the LLVM fuzzer.
28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
when this assertion was used as a condition, for example (?(?!)a|b). In
pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
error about an unsupported item.
29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
possessification code could take exponential time to complete. A recursion
depth limit of 1000 has been imposed to limit the resources used by this
30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
because \S ensures they are all in the class. The code for doing this was
interacting badly with the code for computing the amount of space needed to
compile the pattern, leading to a buffer overflow. This bug was discovered
by the LLVM fuzzer.
31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
other kinds of group caused stack overflow at compile time. This bug was
discovered by the LLVM fuzzer.
32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
between a subroutine call and its quantifier was incorrectly compiled,
leading to buffer overflow or other errors. This bug was discovered by the
LLVM fuzzer.
33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
assertion after (?(. The code was failing to check the character after
(?(?< for the ! or = that would indicate a lookbehind assertion. This bug
was discovered by the LLVM fuzzer.
34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
a fixed maximum following a group that contains a subroutine reference was
incorrectly compiled and could trigger buffer overflow. This bug was
discovered by the LLVM fuzzer.
35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
caused a stack overflow instead of the diagnosis of a non-fixed length
lookbehind assertion. This bug was discovered by the LLVM fuzzer.
36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
(e.g. /(?<=\Ka)/) could make pcregrep loop.
37. There was a similar problem to 36 in pcretest for global matches.
38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
and a subsequent item in the pattern caused a non-match, backtracking over
the repeated \X did not stop, but carried on past the start of the subject,
causing reference to random memory and/or a segfault. There were also some
other cases where backtracking after \C could crash. This set of bugs was
discovered by the LLVM fuzzer.
39. The function for finding the minimum length of a matching string could take
a very long time if mutual recursion was present many times in a pattern,
for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
method has been implemented. This infelicity was discovered by the LLVM
40. Static linking against the PCRE library using the pkg-config module was
failing on missing pthread symbols.
Version 8.36 26-September-2014
1. Got rid of some compiler warnings in the C++ modules that were shown up by
-Wmissing-field-initializers and -Wunused-parameter.
2. The tests for quantifiers being too big (greater than 65535) were being
applied after reading the number, and stupidly assuming that integer
overflow would give a negative number. The tests are now applied as the
numbers are read.
3. Tidy code in pcre_exec.c where two branches that used to be different are
now the same.
4. The JIT compiler did not generate match limit checks for certain
bracketed expressions with quantifiers. This may lead to exponential
backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
issue should be resolved now.
5. Fixed an issue, which occures when nested alternatives are optimized
with table jumps.
6. Inserted two casts and changed some ints to size_t in the light of some
reported 64-bit compiler warnings (Bugzilla 1477).
7. Fixed a bug concerned with zero-minimum possessive groups that could match
an empty string, which sometimes were behaving incorrectly in the
interpreter (though correctly in the JIT matcher). This pcretest input is
an example:
the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
for an empty string was breaking the inner loop and carrying on at a lower
level, when possessive repeated groups should always return to a higher
level as they have no backtrack points in them. The empty string test now
occurs at the outer level.
8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
10. Change 8.34/15 introduced a bug that caused the amount of memory needed
to hold a pattern to be incorrectly computed (too small) when there were
named back references to duplicated names. This could cause "internal
error: code overflow" or "double free or corruption" or other memory
handling errors.
11. When named subpatterns had the same prefixes, back references could be
confused. For example, in this pattern:
the reference to 'Name' was incorrectly treated as a reference to a
duplicate name.
12. A pattern such as /^s?c/mi8 where the optional character has more than
one "other case" was incorrectly compiled such that it would only try to
match starting at "c".
13. When a pattern starting with \s was studied, VT was not included in the
list of possible starting characters; this should have been part of the
8.34/18 patch.
14. If a character class started [\Qx]... where x is any character, the class
was incorrectly terminated at the ].
15. If a pattern that started with a caseless match for a character with more
than one "other case" was studied, PCRE did not set up the starting code
unit bit map for the list of possible characters. Now it does. This is an
optimization improvement, not a bug fix.
16. The Unicode data tables have been updated to Unicode 7.0.0.
17. Fixed a number of memory leaks in pcregrep.
18. Avoid a compiler warning (from some compilers) for a function call with
a cast that removes "const" from an lvalue by using an intermediate
variable (to which the compiler does not object).
19. Incorrect code was compiled if a group that contained an internal recursive
back reference was optional (had quantifier with a minimum of zero). This
example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
caused segmentation faults because of stack overflows at compile time.
20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
group that is quantified with an indefinite repeat, caused a compile-time
loop which used up all the system stack and provoked a segmentation fault.
This was not the same bug as 19 above.
21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
Patch by Mike Frysinger.
Version 8.35 04-April-2014
1. A new flag is set, when property checks are present in an XCLASS.
When this flag is not set, PCRE can perform certain optimizations
such as studying these XCLASS-es.
2. The auto-possessification of character sets were improved: a normal
and an extended character set can be compared now. Furthermore
the JIT compiler optimizes more character set checks.
3. Got rid of some compiler warnings for potentially uninitialized variables
that show up only when compiled with -O2.
4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
of a match later then the end of the match. The pcretest program was not
handling the case sensibly - it was outputting from the start to the next
binary zero. It now reports this situation in a message, and outputs the
text from the end to the start.
5. Fast forward search is improved in JIT. Instead of the first three
characters, any three characters with fixed position can be searched.
Search order: first, last, middle.
6. Improve character range checks in JIT. Characters are read by an inprecise
function now, which returns with an unknown value if the character code is
above a certain threshold (e.g: 256). The only limitation is that the value
must be bigger than the threshold as well. This function is useful when
the characters above the threshold are handled in the same way.
7. The macros whose names start with RAWUCHAR are placeholders for a future
mode in which only the bottom 21 bits of 32-bit data items are used. To
make this more memorable for those maintaining the code, the names have
been changed to start with UCHAR21, and an extensive comment has been added
to their definition.
8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
to the export list in Makefile.am (they were accidentally omitted from the
8.34 tarball).
9. The informational output from pcretest used the phrase "starting byte set"
which is inappropriate for the 16-bit and 32-bit libraries. As the output
for "first char" and "need char" really means "non-UTF-char", I've changed
"byte" to "char", and slightly reworded the output. The documentation about
these values has also been (I hope) clarified.
10. Another JIT related optimization: use table jumps for selecting the correct
backtracking path, when more than four alternatives are present inside a
11. Empty match is not possible, when the minimum length is greater than zero,
and there is no \K in the pattern. JIT should avoid empty match checks in
such cases.
12. In a caseless character class with UCP support, when a character with more
than one alternative case was not the first character of a range, not all
the alternative cases were added to the class. For example, s and \x{17f}
are both alternative cases for S: the class [RST] was handled correctly,
but [R-T] was not.
13. The configure.ac file always checked for pthread support when JIT was
enabled. This is not used in Windows, so I have put this test inside a
check for the presence of windows.h (which was already tested for).
14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
The algorithm provides a way to skip certain starting offsets, and usually
faster than linear prefix searches.
15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
as for 'fr_FR' and 'french'. For some reason, however, it then used the
Windows-specific input and output files, which have 'french' screwed in.
So this could never have worked. One of the problems with locales is that
they aren't always the same. I have now updated RunTest so that it checks
the output of the locale test (test 3) against three different output
files, and it allows the test to pass if any one of them matches. With luck
this should make the test pass on some versions of Solaris where it was
failing. Because of the uncertainty, the script did not used to stop if
test 3 failed; it now does. If further versions of a French locale ever
come to light, they can now easily be added.
16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
there was a message during ./configure, but it did not stop. This now
provokes an error. The invalid example in README has been corrected.
If a value less than the minimum is given, the minimum value has always
been used, but now a warning is given.
17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
was a bug in the test system, which is now fixed. Also, the list of various
configurations that are tested for each release did not have one with both
16/32 bits and --enable-bar-anycrlf. It now does.
18. pcretest was missing "-C bsr" for displaying the \R default setting.
19. Little endian PowerPC systems are supported now by the JIT compiler.
20. The fast forward newline mechanism could enter to an infinite loop on
certain invalid UTF-8 input. Although we don't support these cases
this issue can be fixed by a performance optimization.
21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
not take account if existing stack usage. There is now a new global
variable called pcre_stack_guard that can be set to point to an external
function to check stack availability. It is called at the start of
processing every parenthesized group.
22. A typo in the code meant that in ungreedy mode the max/min qualifier
behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
not match "ab".
23. When UTF was disabled, the JIT program reported some incorrect compile
errors. These messages are silenced now.
24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
25. Change all the temporary files used in RunGrepTest to be different to those
used by RunTest so that the tests can be run simultaneously, for example by
"make -j check".
Version 8.34 15-December-2013
1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
executable memory. Patch inspired by Carsten Klein.
2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
this macro is never tested and has no effect, because the work to support
coverage involves only compiling and linking options and special targets in
the Makefile. The comment in config.h implied that defining the macro would
enable coverage support, which is totally false. There was also support for
setting this macro in the CMake files (my fault, I just copied it from
configure). SUPPORT_GCOV has now been removed.
3. Make a small performance improvement in strlen16() and strlen32() in
4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
these cases). There was also one in pcretest.c.
5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
6. In UTF mode, the code for checking whether a group could match an empty
string (which is used for indefinitely repeated groups to allow for
breaking an infinite loop) was broken when the group contained a repeated
negated single-character class with a character that occupied more than one
data item and had a minimum repetition of zero (for example, [^\x{100}]* in
UTF-8 mode). The effect was undefined: the group might or might not be
deemed as matching an empty string, or the program might have crashed.
7. The code for checking whether a group could match an empty string was not
recognizing that \h, \H, \v, \V, and \R must match a character.
8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
an empty string. If it can, pcretest shows this in its information output.
9. Fixed two related bugs that applied to Unicode extended grapheme clusters
that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
matched by pcre_exec() without using JIT:
(a) If the rest of the pattern did not match after a maximal run of
grapheme clusters, the code for backing up to try with fewer of them
did not always back up over a full grapheme when characters that do not
have the modifier quality were involved, e.g. Hangul syllables.
(b) If the match point in a subject started with modifier character, and
there was no match, the code could incorrectly back up beyond the match
point, and potentially beyond the first character in the subject,
leading to a segfault or an incorrect match result.
10. A conditional group with an assertion condition could lead to PCRE
recording an incorrect first data item for a match if no other first data
item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
first data item, and therefore matched "ca" after "c" instead of at the
11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
12. The source of pcregrep now includes z/OS-specific code so that it can be
compiled for z/OS as part of the special z/OS distribution.
13. Added the -T and -TM options to pcretest.
14. The code in pcre_compile.c for creating the table of named capturing groups
has been refactored. Instead of creating the table dynamically during the
actual compiling pass, the information is remembered during the pre-compile
pass (on the stack unless there are more than 20 named groups, in which
case malloc() is used) and the whole table is created before the actual
compile happens. This has simplified the code (it is now nearly 150 lines
shorter) and prepared the way for better handling of references to groups
with duplicate names.
15. A back reference to a named subpattern when there is more than one of the
same name now checks them in the order in which they appear in the pattern.
The first one that is set is used for the reference. Previously only the
first one was inspected. This change makes PCRE more compatible with Perl.
16. Unicode character properties were updated from Unicode 6.3.0.
17. The compile-time code for auto-possessification has been refactored, based
on a patch by Zoltan Herczeg. It now happens after instead of during
compilation. The code is cleaner, and more cases are handled. The option
PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
options in pcretest are provided to set it. It can also be set by
(*NO_AUTO_POSSESS) at the start of a pattern.
18. The character VT has been added to the default ("C" locale) set of
characters that match \s and are generally treated as white space,
following this same change in Perl 5.18. There is now no difference between
"Perl space" and "POSIX space". Whether VT is treated as white space in
other locales depends on the locale.
19. The code for checking named groups as conditions, either for being set or
for being recursed, has been refactored (this is related to 14 and 15
above). Processing unduplicated named groups should now be as fast at
numerical groups, and processing duplicated groups should be faster than
20. Two patches to the CMake build system, by Alexander Barkov:
(1) Replace the "source" command by "." in CMakeLists.txt because
"source" is a bash-ism.
(2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
without these the CMake build does not work on Solaris.
21. Perl has changed its handling of \8 and \9. If there is no previously
encountered capturing group of those numbers, they are treated as the
literal characters 8 and 9 instead of a binary zero followed by the
literals. PCRE now does the same.
22. Following Perl, added \o{} to specify codepoints in octal, making it
possible to specify values greater than 0777 and also making them
23. Perl now gives an error for missing closing braces after \x{... instead of
treating the string as literal. PCRE now does the same.
24. RunTest used to grumble if an inappropriate test was selected explicitly,
but just skip it when running all tests. This make it awkward to run ranges
of tests when one of them was inappropriate. Now it just skips any
inappropriate tests, as it always did when running all tests.
25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
character types such as \d or \w, too many callouts were inserted, and the
data that they returned was rubbish.
26. In UCP mode, \s was not matching two of the characters that Perl matches,
namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
were matched by \h. The code has now been refactored so that the lists of
the horizontal and vertical whitespace characters used for \h and \v (which
are defined only in one place) are now also used for \s.
27. Add JIT support for the 64 bit TileGX architecture.
Patch by Jiong Wang (Tilera Corporation).
28. Possessive quantifiers for classes (both explicit and automatically
generated) now use special opcodes instead of wrapping in ONCE brackets.
29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
(because it's meaningless), this was not happening when PCRE_CASELESS was
set. Not wrong, but inefficient.
30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
properties for \w, \d, etc) is present in a test regex. Otherwise if the
test contains no characters greater than 255, Perl doesn't realise it
should be using Unicode semantics.
31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
[:punct:] when PCRE_UCP is set so as to include the same characters as Perl
does in Unicode mode.
32. Added the "forbid" facility to pcretest so that putting tests into the
wrong test files can sometimes be quickly detected.
33. There is now a limit (default 250) on the depth of nesting of parentheses.
This limit is imposed to control the amount of system stack used at compile
time. It can be changed at build time by --with-parens-nest-limit=xxx or
the equivalent in CMake.
34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
errors. Perl warns for these when in warning mode, but PCRE has no facility
for giving warnings.
35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
However, this was not working for (?!) because it is optimized to (*FAIL),
for which PCRE does not allow quantifiers. The optimization is now disabled
when a quantifier follows (?!). I can't see any use for this, but it makes
things uniform.
36. Perl no longer allows group names to start with digits, so I have made this
change also in PCRE. It simplifies the code a bit.
37. In extended mode, Perl ignores spaces before a + that indicates a
possessive quantifier. PCRE allowed a space before the quantifier, but not
before the possessive +. It now does.
38. The use of \K (reset reported match start) within a repeated possessive
group such as (a\Kb)*+ was not working.
40. Document that the same character tables must be used at compile time and
run time, and that the facility to pass tables to pcre_exec() and
pcre_dfa_exec() is for use only with saved/restored patterns.
41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
features for Builds with MSVC:
1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
builds). The .rc files can be used to set FileDescription and many other
2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
This allows higher-level build scripts which want .pdb files to avoid
hard-coding the exact files needed."
42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
mean "start of word" and "end of word", respectively, as a transition aid.
43. A minimizing repeat of a class containing codepoints greater than 255 in
non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
compiled to use the heap for recursion.
44. Got rid of some compiler warnings for unused variables when UTF but not UCP
is configured.
Version 8.33 28-May-2013
1. Added 'U' to some constants that are compared to unsigned integers, to
avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
variables that are added to signed variables, to ensure the result is
signed and can be negated.
2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
CMake config files.
3. Revise the creation of config.h.generic so that all boolean macros are
#undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
overriding via -D on the command line possible.
4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
to unsigned int is reported to make a quite noticeable speed difference in
a specific Windows environment. Testing on Linux did also appear to show
some benefit (and it is clearly not harmful). Also fixed the definition of
Xop which should be unsigned.
5. Related to (4), changing the definition of the intermediate variable cc
in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
6. Fix forward search in JIT when link size is 3 or greater. Also removed some
unnecessary spaces.
7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
and later.
8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
9. Optimizing fast_forward_start_bits in JIT.
10. Adding support for callouts in JIT, and fixing some issues revealed
during this work. Namely:
(a) Unoptimized capturing brackets incorrectly reset on backtrack.
(b) Minimum length was not checked before the matching is started.
11. The value of capture_last that is passed to callouts was incorrect in some
cases when there was a capture on one path that was subsequently abandoned
after a backtrack. Also, the capture_last value is now reset after a
recursion, since all captures are also reset in this case.
12. The interpreter no longer returns the "too many substrings" error in the
case when an overflowing capture is in a branch that is subsequently
abandoned after a backtrack.
13. In the pathological case when an offset vector of size 2 is used, pcretest
now prints out the matched string after a yield of 0 or 1.
14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
Only supported by the JIT compiler at the moment.
15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
offset of the starting point of the matching process, provided the offsets
vector is large enough.
17. The \A escape now records a lookbehind value of 1, though its execution
does not actually inspect the previous character. This is to ensure that,
in partial multi-segment matching, at least one character from the old
segment is retained when a new segment is processed. Otherwise, if there
are no lookbehinds in the pattern, \A might match incorrectly at the start
of a new segment.
18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
gives some modest performance improvement in 8-bit mode.
20. Added the PCRE-specific property \p{Xuc} for matching characters that can
be expressed in certain programming languages using Universal Character
21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
which points out that "non characters" are not "characters that may not
appear in Unicode strings" but rather "characters that are reserved for
internal use and have only local meaning".
22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
there was a conditional group that depended on an assertion, if the
assertion was false, the callout that immediately followed the alternation
in the condition was skipped when pcre_exec() was used for matching.
23. Allow an explicit callout to be inserted before an assertion that is the
condition for a conditional group, for compatibility with automatic
callouts, which always insert a callout at this point.
24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
25. (*PRUNE) is now supported by the JIT compiler.
26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
27. Fix the case where there are two or more SKIPs with arguments that may be
28. (*SKIP) is now supported by the JIT compiler.
29. (*THEN) is now supported by the JIT compiler.
30. Update RunTest with additional test selector options.
31. The way PCRE handles backtracking verbs has been changed in two ways.
(1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
backtracking. In some cases this makes it more Perl-compatible, but Perl's
rather obscure rules do not always do the same thing.
(2) Previously, backtracking verbs were confined within assertions. This is
no longer the case for positive assertions, except for (*ACCEPT). Again,
this sometimes improves Perl compatibility, and sometimes does not.
32. A number of tests that were in test 2 because Perl did things differently
have been moved to test 1, because either Perl or PCRE has changed, and
these tests are now compatible.
32. Backtracking control verbs are now handled in the same way in JIT and
33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
contained a forward subroutine reference caused a compile error.
34. Auto-detect and optimize limited repetitions in JIT.
35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
blocking (*UTF) etc.
36. In the interpreter, maximizing pattern repetitions for characters and
character types now use tail recursion, which reduces stack usage.
37. The value of the max lookbehind was not correctly preserved if a compiled
and saved regex was reloaded on a host of different endianness.
38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
of the compiled pattern block, expand the flags field from 16 to 32 bits
because it was almost full.
39. Try madvise first before posix_madvise.
40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
with a pattern such as ^$. It has taken 4 years for anybody to notice! The
original change locked out all matches of empty strings. This has been
changed so that one match of an empty string per line is recognized.
Subsequent searches on the same line (for colouring or for --only-matching,
for example) do not recognize empty strings.
41. Applied a user patch to fix a number of spelling mistakes in comments.
42. Data lines longer than 65536 caused pcretest to crash.
43. Clarified the data type for length and startoffset arguments for pcre_exec
and pcre_dfa_exec in the function-specific man pages, where they were
explicitly stated to be in bytes, never having been updated. I also added
some clarification to the pcreapi man page.
44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
a segmentation fault.
Version 8.32 30-November-2012
1. Improved JIT compiler optimizations for first character search and single
character iterators.
2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
Patch by Daniel Richard G.
3. Single character iterator optimizations in the JIT compiler.
4. Improved JIT compiler optimizations for character ranges.
5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
Reported by Giuseppe D'Angelo.
6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
of a line, was being set incorrectly in cases where .* appeared inside
atomic brackets at the start of a pattern, or where there was a subsequent
7. Improved instruction cache flush for POWER/PowerPC.
Patch by Daniel Richard G.
8. Fixed a number of issues in pcregrep, making it more compatible with GNU
(a) There is now no limit to the number of patterns to be matched.
(b) An error is given if a pattern is too long.
(c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
are now supported.
(d) --exclude-from and --include-from (multiple use) have been added.
(e) Exclusions and inclusions now apply to all files and directories, not
just to those obtained from scanning a directory recursively.
(f) Multiple uses of -f and --file-list are now supported.
(g) In a Windows environment, the default for -d has been changed from
"read" (the GNU grep default) to "skip", because otherwise the presence
of a directory in the file list provokes an error.
(h) The documentation has been revised and clarified in places.
9. Improve the matching speed of capturing brackets.
10. Changed the meaning of \X so that it now matches a Unicode extended
grapheme cluster.
11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
out POSIX threads when JIT support is configured.
12. Added support for PCRE_STUDY_EXTRA_NEEDED.
13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
structure could go wrong in environments where size_t is not the same size
as int.
14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
15. The EBCDIC support had decayed; later updates to the code had included
explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
general tidy up of EBCDIC-related issues, and the documentation was also
not quite right. There is now a test that can be run on ASCII systems to
check some of the EBCDIC-related things (but is it not a full test).
16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
in a small tidy to the code.
17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
18. If the --only-matching (-o) option in pcregrep is specified multiple
times, each one causes appropriate output. For example, -o1 -o2 outputs the
substrings matched by the 1st and 2nd capturing parentheses. A separating
string can be specified by --om-separator (default empty).
19. Improving the first n character searches.
20. Turn case lists for horizontal and vertical white space into macros so that
they are defined only once.
21. This set of changes together give more compatible Unicode case-folding
behaviour for characters that have more than one other case when UCP
support is available.
(a) The Unicode property table now has offsets into a new table of sets of
three or more characters that are case-equivalent. The MultiStage2.py
script that generates these tables (the pcre_ucd.c file) now scans
CaseFolding.txt instead of UnicodeData.txt for character case
(b) The code for adding characters or ranges of characters to a character
class has been abstracted into a generalized function that also handles
case-independence. In UTF-mode with UCP support, this uses the new data
to handle characters with more than one other case.
(c) A bug that is fixed as a result of (b) is that codepoints less than 256
whose other case is greater than 256 are now correctly matched
caselessly. Previously, the high codepoint matched the low one, but not
vice versa.
(d) The processing of \h, \H, \v, and \ in character classes now makes use
of the new class addition function, using character lists defined as
macros alongside the case definitions of 20 above.
(e) Caseless back references now work with characters that have more than
one other case.
(f) General caseless matching of characters with more than one other case
is supported.
22. Unicode character properties were updated from Unicode 6.2.0
23. Improved CMake support under Windows. Patch by Daniel Richard G.
24. Add support for 32-bit character strings, and UTF-32
25. Major JIT compiler update (code refactoring and bugfixing).
Experimental Sparc 32 support is added.
26. Applied a modified version of Daniel Richard G's patch to create
pcre.h.generic and config.h.generic by "make" instead of in the
PrepareRelease script.
27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
pcre_compile.c when checking for a zero character.
28. Introducing a native interface for JIT. Through this interface, the compiled
machine code can be directly executed. The purpose of this interface is to
provide fast pattern matching, so several sanity checks are not performed.
However, feature tests are still performed. The new interface provides
1.4x speedup compared to the old one.
29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
greater than 0x7fffffff (which cannot be represented in UTF-8, even under
the "old" RFC 2279). Instead, it ended up passing a negative length to
31. Add support for GCC's visibility feature to hide internal functions.
32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
"unknown -C option" after outputting 0 or 1.
33. There is now support for generating a code coverage report for the test
suite in environments where gcc is the compiler and lcov is installed. This
is mainly for the benefit of the developers.
34. If PCRE is built with --enable-valgrind, certain memory regions are marked
unaddressable using valgrind annotations, allowing valgrind to detect
invalid memory accesses. This is mainly for the benefit of the developers.
25. (*UTF) can now be used to start a pattern in any of the three libraries.
26. Give configure error if --enable-cpp but no C++ compiler found.
Version 8.31 06-July-2012
1. Fixing a wrong JIT test case and some compiler warnings.
2. Removed a bashism from the RunTest script.
3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
to unsigned type, result still unsigned" that was given by an MS compiler
on encountering the code "-sizeof(xxx)".
4. Partial matching support is added to the JIT compiler.
5. Fixed several bugs concerned with partial matching of items that consist
of more than one character:
(a) /^(..)\1/ did not partially match "aba" because checking references was
done on an "all or nothing" basis. This also applied to repeated
(b) \R did not give a hard partial match if \r was found at the end of the
(c) \X did not give a hard partial match after matching one or more
characters at the end of the subject.
(d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
a partial match for the string "\r".
(e) When newline was set to CRLF, the metacharacter "." did not recognize
a partial match for a CR character at the end of the subject string.
6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
running pcretest, the text "(JIT)" added to the output whenever JIT is
actually used to run the match.
7. Individual JIT compile options can be set in pcretest by following -s+[+]
or /S+[+] with a digit between 1 and 7.
8. OP_NOT now supports any UTF character not just single-byte ones.
9. (*MARK) control verb is now supported by the JIT compiler.
10. The command "./RunTest list" lists the available tests without actually
running any of them. (Because I keep forgetting what they all are.)
12. Applied a (slightly modified) user-supplied patch that improves performance
when the heap is used for recursion (compiled with --disable-stack-for-
recursion). Instead of malloc and free for each heap frame each time a
logical recursion happens, frames are retained on a chain and re-used where
possible. This sometimes gives as much as 30% improvement.
13. As documented, (*COMMIT) is now confined to within a recursive subpattern
14. As documented, (*COMMIT) is now confined to within a positive assertion.
15. It is now possible to link pcretest with libedit as an alternative to
16. (*COMMIT) control verb is now supported by the JIT compiler.
17. The Unicode data tables have been updated to Unicode 6.1.0.
18. Added --file-list option to pcregrep.
19. Added binary file support to pcregrep, including the -a, --binary-files,
-I, and --text options.
20. The madvise function is renamed for posix_madvise for QNX compatibility
reasons. Fixed by Giuseppe D'Angelo.
21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
22. Changed the option for creating symbolic links for 16-bit man pages from
-s to -sf so that re-installing does not cause issues.
23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
24. Fixed a very old bug in pcretest that caused errors with restarted DFA
matches in certain environments (the workspace was not being correctly
retained). Also added to pcre_dfa_exec() a simple plausibility check on
some of the workspace data at the beginning of a restart.
25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
was not doing so when it should - probably a typo introduced by SVN 528
(change 8.10/14).
26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
\w+ when the character tables indicated that \x{c4} was a word character.
There were several related cases, all because the tests for doing a table
lookup were testing for characters less than 127 instead of 255.
27. If a pattern contains capturing parentheses that are not used in a match,
their slots in the ovector are set to -1. For those that are higher than
any matched groups, this happens at the end of processing. In the case when
there were back references that the ovector was too small to contain
(causing temporary malloc'd memory to be used during matching), and the
highest capturing number was not used, memory off the end of the ovector
was incorrectly being set to -1. (It was using the size of the temporary
memory instead of the true size.)
28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
ovector size, it uses memory at the end of the block that it has got.
29. Check for an overlong MARK name and give an error at compile time. The
limit is 255 for the 8-bit library and 65535 for the 16-bit library.
30. JIT compiler update.
31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
Rill for the patch.
32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
33. Variable renamings in the PCRE-JIT compiler. No functionality change.
34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
was enabled.
35. Improve JIT code generation for greedy plus quantifier.
36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1 to "aa" instead of to an empty string. The bug affected repeated groups
that could potentially match an empty string.
37. Optimizing single character iterators in JIT.
38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
the same checks as \x{...} characters in non-JavaScript mode. Specifically,
codepoints that are too big for the mode are faulted, and in a UTF mode,
disallowed codepoints are also faulted.
39. If PCRE was compiled with UTF support, in three places in the DFA
matcher there was code that should only have been obeyed in UTF mode, but
was being obeyed unconditionally. In 8-bit mode this could cause incorrect
processing when bytes with values greater than 127 were present. In 16-bit
mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
both cases the values are those that cannot be the first data item in a UTF
character. The three items that might have provoked this were recursions,
possessively repeated groups, and atomic groups.
40. Ensure that libpcre is explicitly listed in the link commands for pcretest
and pcregrep, because some OS require shared objects to be explicitly
passed to ld, causing the link step to fail if they are not.
41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
mode, patterns that started with \h* or \R* might be incorrectly matched.
Version 8.30 04-February-2012
1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
name is defined in ctype.h.
2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
only in quite long subpatterns.
3. Removed the function pcre_info(), which has been obsolete and deprecated
since it was replaced by pcre_fullinfo() in February 2000.
4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
match a (*MARK), and the match failed at the start of the subject, a
reference to memory before the start of the subject could occur. This bug
was introduced by fix 17 of release 8.21.
5. A reference to an unset group with zero minimum repetition was giving
totally wrong answers (in non-JavaScript-compatibility mode). For example,
/(another)?(\1?)test/ matched against "hello world test". This bug was
introduced in release 8.13.
6. Add support for 16-bit character strings (a large amount of work involving
many changes and refactorings).
7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
from a file.
8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
rounding is not applied in this particular case).
9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
if they appear, or are escaped, in patterns.
10. Get rid of a number of -Wunused-but-set-variable warnings.
11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
"x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
also returns the mark "x". This bug applied to capturing parentheses,
non-capturing parentheses, and atomic parentheses. It also applied to some
12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
information out of configure.ac instead of relying on pcre.h.generic, which
is not stored in the repository.
13. Applied Dmitry V. Levin's patch for a more portable method for linking with
14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
15. Applied Graycode's patch to put the top-level frame on the stack rather
than the heap when not using the stack for recursion. This gives a
performance improvement in many cases when recursion is not deep.
16. Experimental code added to "pcretest -C" to output the stack frame size.
Version 8.21 12-Dec-2011
1. Updating the JIT compiler.
2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
are added as well.
3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
calling _pcre_jit_exec. Some extra comments are added.
4. (*MARK) settings inside atomic groups that do not contain any capturing
parentheses, for example, (?>a(*:m)), were not being passed out. This bug
was introduced by change 18 for 8.20.
5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
ECMA-262 standard.
6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
This bug was probably introduced by change 9 of 8.13.
7. While fixing 6 above, I noticed that a number of other items were being
incorrectly rejected as "not fixed length". This arose partly because newer
opcodes had not been added to the fixed-length checking code. I have (a)
corrected the bug and added tests for these items, and (b) arranged for an
error to occur if an unknown opcode is encountered while checking for fixed
length instead of just assuming "not fixed length". The items that were
rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
(*THEN), \h, \H, \v, \V, and single character negative classes with fixed
repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
being incorrectly compiled and would have given unpredicatble results.
9. A possessively repeated subpattern with minimum repeat count greater than
one behaved incorrectly. For example, (A){2,}+ behaved as if it was
(A)(A)++ which meant that, after a subsequent mismatch, backtracking into
the first (A) could occur when it should not.
10. Add a cast and remove a redundant test from the code.
11. JIT should use pcre_malloc/pcre_free for allocation.
12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
best practice nowadays, and helps with cross-compiling. (If the exec_prefix
is anything other than /usr, -L is still shown).
13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
14. Perl does not support \N without a following name in a [] class; PCRE now
also gives an error.
15. If a forward reference was repeated with an upper limit of around 2000,
it caused the error "internal error: overran compiling workspace". The
maximum number of forward references (including repeats) was limited by the
internal workspace, and dependent on the LINK_SIZE. The code has been
rewritten so that the workspace expands (via pcre_malloc) if necessary, and
the default depends on LINK_SIZE. There is a new upper limit (for safety)
of around 200,000 forward references. While doing this, I also speeded up
the filling in of repeated forward references.
16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
incorrectly expecting the subject to contain another "a" after the start.
17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
in the match, the SKIP should be ignored. This was not happening; instead
the SKIP was being treated as NOMATCH. For patterns such as
/A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
now much more compatible with Perl, in particular in cases where the result
is a non-match for a non-anchored pattern. For example, if
/b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
"m", where previously it did not return a name. A side effect of this
change is that for partial matches, the last encountered mark name is
returned, as for non matches. A number of tests that were previously not
Perl-compatible have been moved into the Perl-compatible test files. The
refactoring has had the pleasing side effect of removing one argument from
the match() function, thus reducing its stack requirements.
19. If the /S+ option was used in pcretest to study a pattern using JIT,
subsequent uses of /S (without +) incorrectly behaved like /S+.
21. Retrieve executable code size support for the JIT compiler and fixing
some warnings.
22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
not work when the shorter character appeared right at the end of the
subject string.
23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
output it when the /M option is used in pcretest.
25. The CheckMan script was not being included in the distribution. Also, added
an explicit "perl" to run Perl scripts from the PrepareRelease script
because this is reportedly needed in Windows.
26. If study data was being save in a file and studying had not found a set of
"starts with" bytes for the pattern, the data written to the file (though
never used) was taken from uninitialized memory and so caused valgrind to
27. Updated RunTest.bat as provided by Sheri Pierce.
28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
29. Computation of memory usage for the table of capturing group names was
giving an unnecessarily large value.
Version 8.20 21-Oct-2011
1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
a POSIX class. After further experiments with Perl, which convinced me that
Perl has bugs and confusions, a closing square bracket is no longer allowed
in a POSIX name. This bug also affected patterns with classes that started
with full stops.
2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
captured substring, but while checking the failing first alternative,
substring 1 is temporarily captured. If the output vector supplied to
pcre_exec() was not big enough for this capture, the yield of the function
was still zero ("insufficient space for captured substrings"). This cannot
be totally fixed without adding another stack variable, which seems a lot
of expense for a edge case. However, I have improved the situation in cases
such as /(a)(b)x|abc/ matched against "abc", where the return code
indicates that fewer than the maximum number of slots in the ovector have
been set.
3. Related to (2) above: when there are more back references in a pattern than
slots in the output vector, pcre_exec() uses temporary memory during
matching, and copies in the captures as far as possible afterwards. It was
using the entire output vector, but this conflicts with the specification
that only 2/3 is used for passing back captured substrings. Now it uses
only the first 2/3, for compatibility. This is, of course, another edge
4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
main code base, and can be used by building with --enable-jit. When this is
done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
runtime --no-jit option is given.
5. When the number of matches in a pcre_dfa_exec() run exactly filled the
ovector, the return from the function was zero, implying that there were
other matches that did not fit. The correct "exactly full" value is now
6. If a subpattern that was called recursively or as a subroutine contained
(*PRUNE) or any other control that caused it to give a non-standard return,
invalid errors such as "Error -26 (nested recursion at the same subject
position)" or even infinite loops could occur.
7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
computing the minimum length on reaching *ACCEPT, and so ended up with the
wrong value of 1 rather than 0. Further investigation indicates that
computing a minimum subject length in the presence of *ACCEPT is difficult
(think back references, subroutine calls), and so I have changed the code
so that no minimum is registered for a pattern that contains *ACCEPT.
8. If (*THEN) was present in the first (true) branch of a conditional group,
it was not handled as intended. [But see 16 below.]
9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
Sheri Pierce.
10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
the first byte in a match must be "a".
11. Change 17 for 8.13 increased the recursion depth for patterns like
/a(?:.)*?a/ drastically. I've improved things by remembering whether a
pattern contains any instances of (*THEN). If it does not, the old
optimizations are restored. It would be nice to do this on a per-group
basis, but at the moment that is not feasible.
12. In some environments, the output of pcretest -C is CRLF terminated. This
broke RunTest's code that checks for the link size. A single white space
character after the value is now allowed for.
13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
For "fr", it uses the Windows-specific input and output files.
14. If (*THEN) appeared in a group that was called recursively or as a
subroutine, it did not work as intended. [But see next item.]
15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
pattern fragments (but not containing any | characters). If A and B are
matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
D. In other words, Perl considers parentheses that do not contain any |
characters to be part of a surrounding alternative, whereas PCRE was
treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
differently. PCRE now behaves in the same way as Perl, except in the case
of subroutine/recursion calls such as (?1) which have in any case always
been different (but PCRE had them first :-).
16. Related to 15 above: Perl does not treat the | in a conditional group as
creating alternatives. Such a group is treated in the same way as an
ordinary group without any | characters when processing (*THEN). PCRE has
been changed to match Perl's behaviour.
17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
RunGrepTest script failed.
18. Change 22 for version 13 caused atomic groups to use more stack. This is
inevitable for groups that contain captures, but it can lead to a lot of
stack use in large patterns. The old behaviour has been restored for atomic
groups that do not contain any capturing parentheses.
19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
suppress the check for a minimum subject length at run time. (If it was
given to pcre_exec() or pcre_dfa_exec() it did work.)
20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
fail to work when decoding hex characters in data strings in EBCDIC
21. It appears that in at least one Mac OS environment, the isxdigit() function
is implemented as a macro that evaluates to its argument more than once,
contravening the C 90 Standard (I haven't checked a later standard). There
was an instance in pcretest which caused it to go wrong when processing
\x{...} escapes in subject strings. The has been rewritten to avoid using
things like p++ in the argument of isxdigit().
Version 8.13 16-Aug-2011
1. The Unicode data tables have been updated to Unicode 6.0.0.
2. Two minor typos in pcre_internal.h have been fixed.
3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
4. There were a number of related bugs in the code for matching backrefences
caselessly in UTF-8 mode when codes for the characters concerned were
different numbers of bytes. For example, U+023A and U+2C65 are an upper
and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
(a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
2-byte code at the end of the subject (it thought there wasn't enough data
5. Comprehensive information about what went wrong is now returned by
pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
as the output vector has at least 2 elements. The offset of the start of
the failing character and a reason code are placed in the vector.
6. When the UTF-8 string check fails for pcre_compile(), the offset that is
now returned is for the first byte of the failing character, instead of the
last byte inspected. This is an incompatible change, but I hope it is small
enough not to be a problem. It makes the returned offset consistent with
pcre_exec() and pcre_dfa_exec().
7. pcretest now gives a text phrase as well as the error number when
pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
failure, the offset and reason code are output.
8. When \R was used with a maximizing quantifier it failed to skip backwards
over a \r\n pair if the subsequent match failed. Instead, it just skipped
back over a single character (\n). This seems wrong (because it treated the
two characters as a single entity when going forwards), conflicts with the
documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
has been changed.
9. Some internal refactoring has changed the processing so that the handling
of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
time (the PCRE_DOTALL option was changed this way some time ago: version
7.7 change 16). This has made it possible to abolish the OP_OPT op code,
which was always a bit of a fudge. It also means that there is one less
argument for the match() function, which reduces its stack requirements
slightly. This change also fixes an incompatibility with Perl: the pattern
(?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
10. More internal refactoring has drastically reduced the number of recursive
calls to match() for possessively repeated groups such as (abc)++ when
using pcre_exec().
11. While implementing 10, a number of bugs in the handling of groups were
discovered and fixed:
(?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
(a|)*(?1) gave a compile-time internal error.
((a|)+)+ did not notice that the outer group could match an empty string.
(^a|^)+ was not marked as anchored.
(.*a|.*)+ was not marked as matching at start or after a newline.
12. Yet more internal refactoring has removed another argument from the match()
function. Special calls to this function are now indicated by setting a
value in a variable in the "match data" data block.
13. Be more explicit in pcre_study() instead of relying on "default" for
opcodes that mean there is no starting character; this means that when new
ones are added and accidentally left out of pcre_study(), testing should
pick them up.
14. The -s option of pcretest has been documented for ages as being an old
synonym of -m (show memory usage). I have changed it to mean "force study
for every regex", that is, assume /S for every regex. This is similar to -i
and -d etc. It's slightly incompatible, but I'm hoping nobody is still
using it. It makes it easier to run collections of tests with and without
study enabled, and thereby test pcre_study() more easily. All the standard
tests are now run with and without -s (but some patterns can be marked as
"never study" - see 20 below).
15. When (*ACCEPT) was used in a subpattern that was called recursively, the
restoration of the capturing data to the outer values was not happening
16. If a recursively called subpattern ended with (*ACCEPT) and matched an
empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
pattern had matched an empty string, and so incorrectly returned a no
17. There was optimizing code for the last branch of non-capturing parentheses,
and also for the obeyed branch of a conditional subexpression, which used
tail recursion to cut down on stack usage. Unfortunately, now that there is
the possibility of (*THEN) occurring in these branches, tail recursion is
no longer possible because the return has to be checked for (*THEN). These
two optimizations have therefore been removed. [But see 8.20/11 above.]
18. If a pattern containing \R was studied, it was assumed that \R always
matched two bytes, thus causing the minimum subject length to be
incorrectly computed because \R can also match just one byte.
19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
was incorrectly computed.
20. If /S is present twice on a test pattern in pcretest input, it now
*disables* studying, thereby overriding the use of -s on the command line
(see 14 above). This is necessary for one or two tests to keep the output
identical in both cases.
21. When (*ACCEPT) was used in an assertion that matched an empty string and
PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
22. When an atomic group that contained a capturing parenthesis was
successfully matched, but the branch in which it appeared failed, the
capturing was not being forgotten if a higher numbered group was later
captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
group 1 to "a", when in fact it should be unset. This applied to multi-
branched capturing and non-capturing groups, repeated or not, and also to
positive assertions (capturing in negative assertions does not happen
in PCRE) and also to nested atomic groups.
23. Add the ++ qualifier feature to pcretest, to show the remainder of the
subject after a captured substring, to make it easier to tell which of a
number of identical substrings has been captured.
24. The way atomic groups are processed by pcre_exec() has been changed so that
if they are repeated, backtracking one repetition now resets captured
values correctly. For example, if ((?>(a+)b)+aabab) is matched against
"aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
"aaa". Previously, it would have been "a". As part of this code
refactoring, the way recursive calls are handled has also been changed.
25. If an assertion condition captured any substrings, they were not passed
back unless some other capturing happened later. For example, if
(?(?=(a))a) was matched against "a", no capturing was returned.
26. When studying a pattern that contained subroutine calls or assertions,
the code for finding the minimum length of a possible match was handling
direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
group 1 called group 2 while simultaneously a separate group 2 called group
1). A stack overflow occurred in this case. I have fixed this by limiting
the recursion depth to 10.
27. Updated RunTest.bat in the distribution to the version supplied by Tom
Fortmann. This supports explicit test numbers on the command line, and has
argument validation and error reporting.
28. An instance of \X with an unlimited repeat could fail if at any point the
first character it looked at was a mark character.
29. Some minor code refactoring concerning Unicode properties and scripts
should reduce the stack requirement of match() slightly.
30. Added the '=' option to pcretest to check the setting of unused capturing
slots at the end of the pattern, which are documented as being -1, but are
not included in the return count.
31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
compiled something random. Now it gives a compile-time error (as does
32. A *MARK encountered during the processing of a positive assertion is now
recorded and passed back (compatible with Perl).
33. If --only-matching or --colour was set on a pcregrep call whose pattern
had alternative anchored branches, the search for a second match in a line
was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
matched the line "0102" twice. The same bug affected patterns that started
with a backwards assertion. For example /\b01|\b02/ also matched "0102"
34. Previously, PCRE did not allow quantification of assertions. However, Perl
does, and because of capturing effects, quantifying parenthesized
assertions may at times be useful. Quantifiers are now allowed for
parenthesized assertions.
35. A minor code tidy in pcre_compile() when checking options for \R usage.
36. \g was being checked for fancy things in a character class, when it should
just be a literal "g".
37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
appearance of a nested POSIX class supersedes an apparent external class.
For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
unescaped square brackets may also appear as part of class names. For
example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
more like Perl. (But see 8.20/1 above.)
38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
was because it thought it was \N{name}, which is not supported).
39. Add minix to OS list not supporting the -S option in pcretest.
40. PCRE tries to detect cases of infinite recursion at compile time, but it
cannot analyze patterns in sufficient detail to catch mutual recursions
such as ((?1))((?2)). There is now a runtime test that gives an error if a
subgroup is called recursively as a subpattern for a second time at the
same position in the subject string. In previous releases this might have
been caught by the recursion limit, or it might have run out of stack.
41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
happen only once. PCRE was, however incorrectly giving a compile time error
"recursive call could loop indefinitely" because it cannot analyze the
pattern in sufficient detail. The compile time test no longer happens when
PCRE is compiling a conditional subpattern, but actual runaway loops are
now caught at runtime (see 40 above).
42. It seems that Perl allows any characters other than a closing parenthesis
to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
has been changed to be the same.
43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
as not to get warnings when autogen.sh is called. Also changed
AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
44. To help people who use pcregrep to scan files containing exceedingly long
lines, the following changes have been made:
(a) The default value of the buffer size parameter has been increased from
8K to 20K. (The actual buffer used is three times this size.)
(b) The default can be changed by ./configure --with-pcregrep-bufsize when
PCRE is built.
(c) A --buffer-size=n option has been added to pcregrep, to allow the size
to be set at run time.
(d) Numerical values in pcregrep options can be followed by K or M, for
example --buffer-size=50K.
(e) If a line being scanned overflows pcregrep's buffer, an error is now
given and the return code is set to 2.
45. Add a pointer to the latest mark to the callout data block.
46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
partial match of an empty string instead of no match. This was specific to
the use of ".".
47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
complete match instead of a partial match. This bug was dependent on both
the PCRE_UTF8 and PCRE_DOTALL options being set.
48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
starting byte set, because \b was not being ignored.
Version 8.12 15-Jan-2011
1. Fixed some typos in the markup of the man pages, and wrote a script that
checks for such things as part of the documentation building process.
2. On a big-endian 64-bit system, pcregrep did not correctly process the
--match-limit and --recursion-limit options (added for 8.11). In
particular, this made one of the standard tests fail. (The integer value
went into the wrong half of a long int.)
3. If the --colour option was given to pcregrep with -v (invert match), it
did strange things, either producing crazy output, or crashing. It should,
of course, ignore a request for colour when reporting lines that do not
4. Another pcregrep bug caused similar problems if --colour was specified with
-M (multiline) and the pattern match finished with a line ending.
5. In pcregrep, when a pattern that ended with a literal newline sequence was
matched in multiline mode, the following line was shown as part of the
match. This seems wrong, so I have changed it.
6. Another pcregrep bug in multiline mode, when --colour was specified, caused
the check for further matches in the same line (so they could be coloured)
to overrun the end of the current line. If another match was found, it was
incorrectly shown (and then shown again when found in the next line).
7. If pcregrep was compiled under Windows, there was a reference to the
function pcregrep_exit() before it was defined. I am assuming this was
the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
reported by a user. I've moved the definition above the reference.
Version 8.11 10-Dec-2010
1. (*THEN) was not working properly if there were untried alternatives prior
to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
backtracked to try for "b" instead of moving to the next alternative branch
at the same level (in this case, to look for "c"). The Perl documentation
is clear that when (*THEN) is backtracked onto, it goes to the "next
alternative in the innermost enclosing group".
2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
(*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
3. If \s appeared in a character class, it removed the VT character from
the class, even if it had been included by some previous item, for example
in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
of \s, but is part of the POSIX "space" class.)
4. A partial match never returns an empty string (because you can always
match an empty string at the end of the subject); however the checking for
an empty string was starting at the "start of match" point. This has been
changed to the "earliest inspected character" point, because the returned
data for a partial match starts at this character. This means that, for
example, /(?<=abc)def/ gives a partial match for the subject "abc"
(previously it gave "no match").
5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
previously a full match would be given. However, setting PCRE_PARTIAL_HARD
has an implication that the given string is incomplete (because a partial
match is preferred over a full match). For this reason, these items now
give a partial match in this situation. [Aside: previously, the one case
/t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
match rather than a full match, which was wrong by the old rules, but is
now correct.]
6. There was a bug in the handling of #-introduced comments, recognized when
PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
places in pcre_compile().
7. Related to (6) above, when pcre_compile() was skipping #-introduced
comments when looking ahead for named forward references to subpatterns,
the only newline sequence it recognized was NL. It now handles newlines
according to the set newline convention.
8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
former, but used strtoul(), whereas pcretest avoided strtoul() but did not
cater for a lack of strerror(). These oversights have been fixed.
9. Added --match-limit and --recursion-limit to pcregrep.
10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
11. When the -o option was used, pcregrep was setting a return code of 1, even
when matches were found, and --line-buffered was not being honoured.
12. Added an optional parentheses number to the -o and --only-matching options
of pcregrep.
13. Imitating Perl's /g action for multiple matches is tricky when the pattern
can match an empty string. The code to do it in pcretest and pcredemo
needed fixing:
(a) When the newline convention was "crlf", pcretest got it wrong, skipping
only one byte after an empty string match just before CRLF (this case
just got forgotten; "any" and "anycrlf" were OK).
(b) The pcretest code also had a bug, causing it to loop forever in UTF-8
mode when an empty string match preceded an ASCII character followed by
a non-ASCII character. (The code for advancing by one character rather
than one byte was nonsense.)
(c) The pcredemo.c sample program did not have any code at all to handle
the cases when CRLF is a valid newline sequence.
14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
as a starting offset was within the subject string. There is now a new
error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
negative or greater than the length of the string. In order to test this,
pcretest is extended to allow the setting of negative starting offsets.
15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
starting offset points to the beginning of a UTF-8 character was
unnecessarily clumsy. I tidied it up.
16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
17. Nobody had reported that the --include_dir option, which was added in
release 7.7 should have been called --include-dir (hyphen, not underscore)
for compatibility with GNU grep. I have changed it to --include-dir, but
left --include_dir as an undocumented synonym, and the same for
--exclude-dir, though that is not available in GNU grep, at least as of
release 2.5.4.
18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
characters from a string of bytes) have been redefined so as not to use
loops, in order to improve performance in some environments. At the same
time, I abstracted some of the common code into auxiliary macros to save
repetition (this should not affect the compiled code).
19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
compile-time error is now given if \c is not followed by an ASCII
character, that is, a byte less than 128. (In EBCDIC mode, the code is
different, and any byte value is allowed.)
20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
START_OPTIMIZE option, which is now allowed at compile time - but just
passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
to pcregrep and other applications that have no direct access to PCRE
options. The new /Y option in pcretest sets this option when calling
21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
back references. Groups containing recursive back references were forced to
be atomic by that change, but in the case of named groups, the amount of
memory required was incorrectly computed, leading to "Failed: internal
error: code overflow". This has been fixed.
22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
pcretest.c, to avoid build problems in some Borland environments.
Version 8.10 25-Jun-2010
1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
2. (*ACCEPT) was not working when inside an atomic group.
3. Inside a character class, \B is treated as a literal by default, but
faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
causes the error). The code is unchanged, but I tidied the documentation.
4. Inside a character class, PCRE always treated \R and \X as literals,
whereas Perl faults them if its -w option is set. I have changed PCRE so
that it faults them when PCRE_EXTRA is set.
5. Added support for \N, which always matches any character other than
newline. (It is the same as "." when PCRE_DOTALL is not set.)
6. When compiling pcregrep with newer versions of gcc which may have
FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
declared with attribute warn_unused_result" were given. Just casting the
result to (void) does not stop the warnings; a more elaborate fudge is
needed. I've used a macro to implement this.
7. Minor change to pcretest.c to avoid a compiler warning.
8. Added four artifical Unicode properties to help with an option to make
\s etc use properties (see next item). The new properties are: Xan
(alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
use Unicode properties. (*UCP) at the start of a pattern can be used to set
this option. Modified pcretest to add /W to test this facility. Added
REG_UCP to make it available via the POSIX interface.
10. Added --line-buffered to pcregrep.
11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
studied, and the match started with a letter with a code point greater than
127 whose first byte was different to the first byte of the other case of
the letter, the other case of this starting letter was not recognized
12. If a pattern that was studied started with a repeated Unicode property
test, for example, \p{Nd}+, there was the theoretical possibility of
setting up an incorrect bitmap of starting bytes, but fortunately it could
not have actually happened in practice until change 8 above was made (it
added property types that matched character-matching opcodes).
13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
possible starting bytes for non-anchored patterns.
14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
\R, and also a number of cases that involve Unicode properties, both
explicit and implicit when PCRE_UCP is set.
15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
input, it could crash or give wrong results if characters with values
greater than 0xc0 were present in the subject string. (Detail: it assumed
UTF-8 input when processing these items.)
16. Added a lot of (int) casts to avoid compiler warnings in systems where
size_t is 64-bit (#991).
17. Added a check for running out of memory when PCRE is compiled with
--disable-stack-for-recursion (#990).
18. If the last data line in a file for pcretest does not have a newline on
the end, a newline was missing in the output.
19. The default pcre_chartables.c file recognizes only ASCII characters (values
less than 128) in its various bitmaps. However, there is a facility for
generating tables according to the current locale when PCRE is compiled. It
turns out that in some environments, 0x85 and 0xa0, which are Unicode space
characters, are recognized by isspace() and therefore were getting set in
these tables, and indeed these tables seem to approximate to ISO 8859. This
caused a problem in UTF-8 mode when pcre_study() was used to create a list
of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
which of course cannot start UTF-8 characters. I have changed the code so
that only real ASCII characters (less than 128) and the correct starting
bytes for UTF-8 encodings are set for characters greater than 127 when in
UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
20. Added the /T option to pcretest so as to be able to run tests with non-
standard character tables, thus making it possible to include the tests
used for 19 above in the standard set of tests.
21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
reference to a subpattern the other side of a comment that contains an
opening parenthesis caused either an internal compiling error, or a
reference to the wrong subpattern.
Version 8.02 19-Mar-2010
1. The Unicode data tables have been updated to Unicode 5.2.0.
2. Added the option --libs-cpp to pcre-config, but only when C++ support is
3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
original author of that file, following a query about its status.
4. On systems that do not have stdint.h (e.g. Solaris), check for and include
inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
quantifier applied to a forward-referencing subroutine call, could compile
incorrect code or give the error "internal error: previously-checked
referenced subpattern not found".
6. Both MS Visual Studio and Symbian OS have problems with initializing
variables to point to external functions. For these systems, therefore,
pcre_malloc etc. are now initialized to local functions that call the
relevant global functions.
7. There were two entries missing in the vectors called coptable and poptable
in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
I've fixed the data, and added a kludgy way of testing at compile time that
the lengths are correct (equal to the number of opcodes).
8. Following on from 7, I added a similar kludge to check the length of the
eint vector in pcreposix.c.
9. Error texts for pcre_compile() are held as one long string to avoid too
much relocation at load time. To find a text, the string is searched,
counting zeros. There was no check for running off the end of the string,
which could happen if a new error number was added without updating the
10. \K gave a compile-time error if it appeared in a lookbehind assersion.
11. \K was not working if it appeared in an atomic group or in a group that
was called as a "subroutine", or in an assertion. Perl 5.11 documents that
\K is "not well defined" if used in an assertion. PCRE now accepts it if
the assertion is positive, but not if it is negative.
12. Change 11 fortuitously reduced the size of the stack frame used in the
"match()" function of pcre_exec.c by one pointer. Forthcoming
implementation of support for (*MARK) will need an extra pointer on the
stack; I have reserved it now, so that the stack frame size does not
13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
item in branch that calls a recursion is a subroutine call - as in the
second branch in the above example - was incorrectly given the compile-
time error "recursive call could loop indefinitely" because pcre_compile()
was not correctly checking the subroutine for matching a non-empty string.
14. The checks for overrunning compiling workspace could trigger after an
overrun had occurred. This is a "should never occur" error, but it can be
triggered by pathological patterns such as hundreds of nested parentheses.
The checks now trigger 100 bytes before the end of the workspace.
15. Fix typo in configure.ac: "srtoq" should be "strtoq".
Version 8.01 19-Jan-2010
1. If a pattern contained a conditional subpattern with only one branch (in
particular, this includes all (*DEFINE) patterns), a call to pcre_study()
computed the wrong minimum data length (which is of course zero for such
subpatterns). This could cause incorrect "no match" results.
2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
the pattern is reset in the first branch, pcre_compile() failed with
"internal error: code overflow at offset...". This happened only when
the reset was to the original external option setting. (An optimization
abstracts leading options settings into an external setting, which was the
cause of this.)
3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
assertion pattern did not match (meaning that the assertion was true), it
was incorrectly treated as false if the SKIP had been reached during the
matching. This also applied to assertions used as conditions.
4. If an item that is not supported by pcre_dfa_exec() was encountered in an
assertion subpattern, including such a pattern used as a condition,
unpredictable results occurred, instead of the error return
5. The C++ GlobalReplace function was not working like Perl for the special
situation when an empty string is matched. It now does the fancy magic
stuff that is necessary.
6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
removed. (These were left over from very, very early versions of PCRE.)
7. Some cosmetic changes to the code to make life easier when compiling it
as part of something else:
(a) Change DEBUG to PCRE_DEBUG.
(b) In pcre_compile(), rename the member of the "branch_chain" structure
called "current" as "current_branch", to prevent a collision with the
Linux macro when compiled as a kernel module.
(c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
prevent a collision with the Linux macro when compiled as a kernel
8. In pcre_compile() there are some checks for integer overflows that used to
cast potentially large values to (double). This has been changed to that
when building, a check for int64_t is made, and if it is found, it is used
instead, thus avoiding the use of floating point arithmetic. (There is no
other use of FP in PCRE.) If int64_t is not found, the fallback is to
9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2005 (difference between two addresses compared to an unsigned value).
10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
custom one, because of the following reported problem in Windows:
- libbz2 uses the Pascal calling convention (WINAPI) for the functions
under Win32.
- The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
therefore missing the function definition.
- The compiler thus generates a "C" signature for the test function.
- The linker fails to find the "C" function.
- PCRE fails to configure if asked to do so against libbz2.
11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
messages were output:
Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
rerunning libtoolize, to keep the correct libtool macros in-tree.
Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
I have done both of these things.
12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
most of the time, it *can* run out if it is given a pattern that contains a
runaway infinite recursion. I updated the discussion in the pcrestack man
13. Now that we have gone to the x.xx style of version numbers, the minor
version may start with zero. Using 08 or 09 is a bad idea because users
might check the value of PCRE_MINOR in their code, and 08 or 09 may be
interpreted as invalid octal numbers. I've updated the previous comment in
configure.ac, and also added a check that gives an error if 08 or 09 are
14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
causing partial matching to fail when the end of the subject matched \W
in a UTF-8 pattern where \W was quantified with a minimum of 3.
15. There were some discrepancies between the declarations in pcre_internal.h
of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
their definitions. The declarations used "const uschar *" and the
definitions used USPTR. Even though USPTR is normally defined as "const
unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
reported that: "This difference in casting confuses some C++ compilers, for
example, SunCC recognizes above declarations as different functions and
generates broken code for hbpcre." I have changed the declarations to use
16. GNU libtool is named differently on some systems. The autogen.sh script now
tries several variants such as glibtoolize (MacOSX) and libtoolize1x
17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
(strtoXX undefined when compiling pcrecpp.cc). The patch contains this
comment: "Figure out how to create a longlong from a string: strtoll and
equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
instance, but it only takes 2 args instead of 3!"
18. A subtle bug concerned with back references has been fixed by a change of
specification, with a corresponding code fix. A pattern such as
^(xa|=?\1a)+$ which contains a back reference inside the group to which it
refers, was giving matches when it shouldn't. For example, xa=xaaa would
match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
same bug. Such groups have to be quantified to be useful, or contained
inside another quantified group. (If there's no repetition, the reference
can never match.) The problem arises because, having left the group and
moved on to the rest of the pattern, a later failure that backtracks into
the group uses the captured value from the final iteration of the group
rather than the correct earlier one. I have fixed this in PCRE by forcing
any group that contains a reference to itself to be an atomic group; that
is, there cannot be any backtracking into it once it has completed. This is
similar to recursive and subroutine calls.
Version 8.00 19-Oct-09
1. The table for translating pcre_compile() error codes into POSIX error codes
was out-of-date, and there was no check on the pcre_compile() error code
being within the table. This could lead to an OK return being given in
2. Changed the call to open a subject file in pcregrep from fopen(pathname,
"r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
in a Windows environment.
3. The pcregrep --count option prints the count for each file even when it is
zero, as does GNU grep. However, pcregrep was also printing all files when
--files-with-matches was added. Now, when both options are given, it prints
counts only for those files that have at least one match. (GNU grep just
prints the file name in this circumstance, but including the count seems
more useful - otherwise, why use --count?) Also ensured that the
combination -clh just lists non-zero counts, with no names.
4. The long form of the pcregrep -F option was incorrectly implemented as
--fixed_strings instead of --fixed-strings. This is an incompatible change,
but it seems right to fix it, and I didn't think it was worth preserving
the old behaviour.
5. The command line items --regex=pattern and --regexp=pattern were not
recognized by pcregrep, which required --regex pattern or --regexp pattern
(with a space rather than an '='). The man page documented the '=' forms,
which are compatible with GNU grep; these now work.
6. No libpcreposix.pc file was created for pkg-config; there was just
libpcre.pc and libpcrecpp.pc. The omission has been rectified.
7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
when UCP support is not needed, by modifying the Python script that
generates it from Unicode data files. This should not matter if the module
is correctly used as a library, but I received one complaint about 50K of
unwanted data. My guess is that the person linked everything into his
program rather than using a library. Anyway, it does no harm.
8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
was a minimum greater than 1 for a wide character in a possessive
repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
which had an unlimited repeat of a nested, fixed maximum repeat of a wide
character. Chaos in the form of incorrect output or a compiling loop could
9. The restrictions on what a pattern can contain when partial matching is
requested for pcre_exec() have been removed. All patterns can now be
partially matched by this function. In addition, if there are at least two
slots in the offset vector, the offset of the earliest inspected character
for the match and the offset of the end of the subject are set in them when
10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
synonymous with PCRE_PARTIAL, for backwards compatibility, and
PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
and may be more useful for multi-segment matching.
11. Partial matching with pcre_exec() is now more intuitive. A partial match
used to be given if ever the end of the subject was reached; now it is
given only if matching could not proceed because another character was
needed. This makes a difference in some odd cases such as Z(*FAIL) with the
string "Z", which now yields "no match" instead of "partial match". In the
case of pcre_dfa_exec(), "no match" is given if every matching path for the
final character ended with (*FAIL).
12. Restarting a match using pcre_dfa_exec() after a partial match did not work
if the pattern had a "must contain" character that was already found in the
earlier partial match, unless partial matching was again requested. For
example, with the pattern /dog.(body)?/, the "must contain" character is
"g". If the first part-match was for the string "dog", restarting with
"sbody" failed. This bug has been fixed.
13. The string returned by pcre_dfa_exec() after a partial match has been
changed so that it starts at the first inspected character rather than the
first character of the match. This makes a difference only if the pattern
starts with a lookbehind assertion or \b or \B (\K is not supported by
pcre_dfa_exec()). It's an incompatible change, but it makes the two
matching functions compatible, and I think it's the right thing to do.
14. Added a pcredemo man page, created automatically from the pcredemo.c file,
so that the demonstration program is easily available in environments where
PCRE has not been installed from source.
15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
is not the first non-POSIX option to be added. Clearly some people find
these options useful.
17. If a caller to the POSIX matching function regexec() passes a non-zero
value for nmatch with a NULL value for pmatch, the value of
nmatch is forced to zero.
18. RunGrepTest did not have a test for the availability of the -u option of
the diff command, as RunTest does. It now checks in the same way as
RunTest, and also checks for the -b option.
19. If an odd number of negated classes containing just a single character
interposed, within parentheses, between a forward reference to a named
subpattern and the definition of the subpattern, compilation crashed with
an internal error, complaining that it could not find the referenced
subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
[The bug was that it was starting one character too far in when skipping
over the character class, thus treating the ] as data rather than
terminating the class. This meant it could skip too much.]
20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
/g option in pcretest when the pattern contains \K, which makes it possible
to have an empty string match not at the start, even when the pattern is
anchored. Updated pcretest and pcredemo to use this option.
21. If the maximum number of capturing subpatterns in a recursion was greater
than the maximum at the outer level, the higher number was returned, but
with unset values at the outer level. The correct (outer level) value is
now given.
22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
PCRE did not set those parentheses (unlike Perl). I have now found a way to
make it do so. The string so far is captured, making this feature
compatible with Perl.
23. The tests have been re-organized, adding tests 11 and 12, to make it
possible to check the Perl 5.10 features against Perl 5.10.
24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
pattern matches a fixed length string. PCRE did not allow this; now it
does. Neither allows recursion.
25. I finally figured out how to implement a request to provide the minimum
length of subject string that was needed in order to match a given pattern.
(It was back references and recursion that I had previously got hung up
on.) This code has now been added to pcre_study(); it finds a lower bound
to the length of subject needed. It is not necessarily the greatest lower
bound, but using it to avoid searching strings that are too short does give
some useful speed-ups. The value is available to calling programs via
26. While implementing 25, I discovered to my embarrassment that pcretest had
not been passing the result of pcre_study() to pcre_dfa_exec(), so the
study optimizations had never been tested with that matching function.
Oops. What is worse, even when it was passed study data, there was a bug in
pcre_dfa_exec() that meant it never actually used it. Double oops. There
were also very few tests of studied patterns with pcre_dfa_exec().
27. If (?| is used to create subpatterns with duplicate numbers, they are now
allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
on the other side of the coin, they are no longer allowed to have different
names, because these cannot be distinguished in PCRE, and this has caused
confusion. (This is a difference from Perl.)
28. When duplicate subpattern names are present (necessarily with different
numbers, as required by 27 above), and a test is made by name in a
conditional pattern, either for a subpattern having been matched, or for
recursion in such a pattern, all the associated numbered subpatterns are
tested, and the overall condition is true if the condition is true for any
one of them. This is the way Perl works, and is also more like the way
testing by number works.
Version 7.9 11-Apr-09
1. When building with support for bzlib/zlib (pcregrep) and/or readline
(pcretest), all targets were linked against these libraries. This included
libpcre, libpcreposix, and libpcrecpp, even though they do not use these
libraries. This caused unwanted dependencies to be created. This problem
has been fixed, and now only pcregrep is linked with bzlib/zlib and only
pcretest is linked with readline.
2. The "typedef int BOOL" in pcre_internal.h that was included inside the
"#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
moved outside it again, because FALSE and TRUE are already defined in AIX,
but BOOL is not.
3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
4. The pcregrep documentation said spaces were inserted as well as colons (or
hyphens) following file names and line numbers when outputting matching
lines. This is not true; no spaces are inserted. I have also clarified the
wording for the --colour (or --color) option.
5. In pcregrep, when --colour was used with -o, the list of matching strings
was not coloured; this is different to GNU grep, so I have changed it to be
the same.
6. When --colo(u)r was used in pcregrep, only the first matching substring in
each matching line was coloured. Now it goes on to look for further matches
of any of the test patterns, which is the same behaviour as GNU grep.
7. A pattern that could match an empty string could cause pcregrep to loop; it
doesn't make sense to accept an empty string match in pcregrep, so I have
locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
seems to be how GNU grep behaves. [But see later change 40 for release
8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
start or after a newline", because the conditional assertion was not being
correctly handled. The rule now is that both the assertion and what follows
in the first alternative must satisfy the test.
9. If auto-callout was enabled in a pattern with a conditional group whose
condition was an assertion, PCRE could crash during matching, both with
pcre_exec() and pcre_dfa_exec().
10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
used for matching.
11. Unicode property support in character classes was not working for
characters (bytes) greater than 127 when not in UTF-8 mode.
12. Added the -M command line option to pcretest.
14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
15. Added the PCRE_NO_START_OPTIMIZE match-time option.
16. Added comments and documentation about mis-use of no_arg in the C++
17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
from Martin Jerabek that uses macro names for all relevant character and
string constants.
18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
these, but not everybody uses configure.
19. A conditional group that had only one branch was not being correctly
recognized as an item that could match an empty string. This meant that an
enclosing group might also not be so recognized, causing infinite looping
(and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
with the subject "ab", where knowledge that the repeated group can match
nothing is needed in order to break the loop.
20. If a pattern that was compiled with callouts was matched using pcre_dfa_
exec(), but without supplying a callout function, matching went wrong.
21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
leak if the size of the offset vector was greater than 30. When the vector
is smaller, the saved offsets during recursion go onto a local stack
vector, but for larger vectors malloc() is used. It was failing to free
when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
error, in fact).
22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
heapframe that is used only when UTF-8 support is enabled. This caused no
problem, but was untidy.
23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
included within another project.
24. Steven Van Ingelgem's patches to add more options to the CMake support,
slightly modified by me:
(a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
not building pcregrep.
(b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
25. Forward references, both numeric and by name, in patterns that made use of
duplicate group numbers, could behave incorrectly or give incorrect errors,
because when scanning forward to find the reference group, PCRE was not
taking into account the duplicate group numbers. A pattern such as
^X(?3)(a)(?|(b)|(q))(Y) is an example.
26. Changed a few more instances of "const unsigned char *" to USPTR, making
the feature of a custom pointer more persuasive (as requested by a user).
27. Wrapped the definitions of fileno and isatty for Windows, which appear in
pcretest.c, inside #ifndefs, because it seems they are sometimes already
28. Added support for (*UTF8) at the start of a pattern.
29. Arrange for flags added by the "release type" setting in CMake to be shown
in the configuration summary.
Version 7.8 05-Sep-08
1. Replaced UCP searching code with optimized version as implemented for Ad
Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
stage table and inline lookup instead of a function, giving speed ups of 2
to 5 times on some simple patterns that I tested. Permission was given to
distribute the MultiStage2.py script that generates the tables (it's not in
the tarball, but is in the Subversion repository).
2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
a group with a zero qualifier. The result of the study could be incorrect,
or the function might crash, depending on the pattern.
4. Caseless matching was not working for non-ASCII characters in back
references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
It now works when Unicode Property Support is available.
5. In pcretest, an escape such as \x{de} in the data was always generating
a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
non-UTF-8 mode. If the value is greater than 255, it gives a warning about
6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
7. Added two (int) casts to pcregrep when printing the difference of two
pointers, in case they are 64-bit values.
8. Added comments about Mac OS X stack usage to the pcrestack man page and to
test 2 if it fails.
9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
and a #define of that name to empty if it is not externally set. This is to
allow users of MSVC to set it if necessary.
10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
the convenience functions in the pcre_get.c source file.
11. An option change at the start of a pattern that had top-level alternatives
could cause overwriting and/or a crash. This command provoked a crash in
some environments:
printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
This potential security problem was recorded as CVE-2008-2371.
12. For a pattern where the match had to start at the beginning or immediately
after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
pcre_dfa_exec() could read past the end of the passed subject if there was
no match. To help with detecting such bugs (e.g. with valgrind), I modified
pcretest so that it places the subject at the end of its malloc-ed buffer.
13. The change to pcretest in 12 above threw up a couple more cases when pcre_
exec() might read past the end of the data buffer in UTF-8 mode.
14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
the data contained the byte 0x85 as part of a UTF-8 character within its
first line. This applied both to normal and DFA matching.
15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
/^[^d]*?$/8 failed to match "abc".
16. Added a missing copyright notice to pcrecpp_internal.h.
17. Make it more clear in the documentation that values returned from
pcre_exec() in ovector are byte offsets, not character counts.
18. Tidied a few places to stop certain compilers from issuing warnings.
19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
supplied by Stefan Weber. I made a further small update for 7.8 because
there is a change of source arrangements: the pcre_searchfuncs.c module is
replaced by pcre_ucd.c.
Version 7.7 07-May-08
1. Applied Craig's patch to sort out a long long problem: "If we can't convert
a string to a long long, pretend we don't even have a long long." This is
done by checking for the strtoq, strtoll, and _strtoi64 functions.
2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
pre-7.6 versions, which defined a global no_arg variable instead of putting
it in the RE class. (See also #8 below.)
3. Remove a line of dead code, identified by coverity and reported by Nuno
4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
(1) The include/exclude patterns were being applied to the whole pathnames
of files, instead of just to the final components.
(2) If there was more than one level of directory, the subdirectories were
skipped unless they satisfied the include/exclude conditions. This is
inconsistent with GNU grep (and could even be seen as contrary to the
pcregrep specification - which I improved to make it absolutely clear).
The action now is always to scan all levels of directory, and just
apply the include/exclude patterns to regular files.
5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
--exclude_dir in the tests to avoid scanning .svn directories.
6. Applied Craig's patch to the QuoteMeta function so that it escapes the
NUL character as backslash + 0 rather than backslash + NUL, because PCRE
doesn't support NULs in patterns.
7. Added some missing "const"s to declarations of static tables in
pcre_compile.c and pcre_dfa_exec.c.
8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
caused by fix #2 above. (Subsequently also a second patch to fix the
first patch. And a third patch - this was a messy problem.)
9. Applied Craig's patch to remove the use of push_back().
10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
matching function regexec().
11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
which, however, unlike Perl's \g{...}, are subroutine calls, not back
references. PCRE supports relative numbers with this syntax (I don't think
Oniguruma does).
12. Previously, a group with a zero repeat such as (...){0} was completely
omitted from the compiled regex. However, this means that if the group
was called as a subroutine from elsewhere in the pattern, things went wrong
(an internal error was given). Such groups are now left in the compiled
pattern, with a new opcode that causes them to be skipped at execution
13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
to the way PCRE behaves:
(a) A lone ] character is dis-allowed (Perl treats it as data).
(b) A back reference to an unmatched subpattern matches an empty string
(Perl fails the current match path).
(c) A data ] in a character class must be notated as \] because if the
first data character in a class is ], it defines an empty class. (In
Perl it is not possible to have an empty class.) The empty class []
never matches; it forces failure and is equivalent to (*FAIL) or (?!).
The negative empty class [^] matches any one character, independently
of the DOTALL setting.
14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
non-existent subpattern following a character class starting with ']' and
containing () gave an internal compiling error instead of "reference to
non-existent subpattern". Fortunately, when the pattern did exist, the
compiled code was correct. (When scanning forwards to check for the
existence of the subpattern, it was treating the data ']' as terminating
the class, so got the count wrong. When actually compiling, the reference
was subsequently set up correctly.)
15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
it was being rejected as not supported by pcre_dfa_exec(), even though
other assertions are supported. I have made pcre_dfa_exec() support
16. The implementation of 13c above involved the invention of a new opcode,
OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
cannot be changed at match time, I realized I could make a small
improvement to matching performance by compiling OP_ALLANY instead of
OP_ANY for "." when DOTALL was set, and then removing the runtime tests
on the OP_ANY path.
17. Compiling pcretest on Windows with readline support failed without the
following two fixes: (1) Make the unistd.h include conditional on
HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
ncurses library to be included for pcretest when ReadLine support is
requested, but also to allow for it to be overridden. This patch came from
Daniel Bergstr<74>m.
19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
any errors with the current Unicode tables. Thanks to Peter Kankowski for
spotting this.
Version 7.6 28-Jan-08
1. A character class containing a very large number of characters with
codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2. Patch to cut out the "long long" test in pcrecpp_unittest when
HAVE_LONG_LONG is not defined.
3. Applied Christian Ehrlicher's patch to update the CMake build files to
bring them up to date and include new features. This patch includes:
- Fixed PH's badly added libz and libbz2 support.
- Fixed a problem with static linking.
- Added pcredemo. [But later removed - see 7 below.]
- Fixed dftables problem and added an option.
- Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
- Added readline support for pcretest.
- Added an listing of the option settings after cmake has run.
4. A user submitted a patch to Makefile that makes it easy to create
"pcre.dll" under mingw when using Configure/Make. I added stuff to
Makefile.am that cause it to include this special target, without
affecting anything else. Note that the same mingw target plus all
the other distribution libraries and programs are now supported
when configuring with CMake (see 6 below) instead of with
5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
This is an attempt to solve the reported problem "pcrecpp::no_arg is not
exported in the Windows port". It has not yet been confirmed that the patch
solves the problem, but it does no harm.
6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
with CMake, and also correct the comment about stack recursion.
7. Remove the automatic building of pcredemo from the ./configure system and
from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
of a program that users should build themselves after PCRE is installed, so
building it automatically is not really right. What is more, it gave
trouble in some build environments.
8. Further tidies to CMakeLists.txt from Sheri and Christian.
Version 7.5 10-Jan-08
1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
values in parens when parsing an RE using the C++ wrapper."
2. Negative specials like \S did not work in character classes in UTF-8 mode.
Characters greater than 255 were excluded from the class instead of being
3. The same bug as (2) above applied to negated POSIX classes such as
4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
defined or documented. It seems to have been a typo for PCRE_STATIC, so
I have changed it.
5. The construct (?&) was not diagnosed as a syntax error (it referenced the
first named subpattern) and a construct such as (?&a) would reference the
first named subpattern whose name started with "a" (in other words, the
length check was missing). Both these problems are fixed. "Subpattern name
expected" is now given for (?&) (a zero-length name), and this patch also
makes it give the same error for \k'' (previously it complained that that
was a reference to a non-existent subpattern).
6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
this is right because (?- can be followed by option settings as well as by
digits. I have, however, made the messages clearer.
7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
than the number used in the conditional) now cause a compile-time error.
This is actually not compatible with Perl, which accepts such patterns, but
treats the conditional as always being FALSE (as PCRE used to), but it
seems to me that giving a diagnostic is better.
8. Change "alphameric" to the more common word "alphanumeric" in comments
and messages.
9. Fix two occurrences of "backslash" in comments that should have been
10. Remove two redundant lines of code that can never be obeyed (their function
was moved elsewhere).
11. The program that makes PCRE's Unicode character property table had a bug
which caused it to generate incorrect table entries for sequences of
characters that have the same character type, but are in different scripts.
It amalgamated them into a single range, with the script of the first of
them. In other words, some characters were in the wrong script. There were
thirteen such cases, affecting characters in the following ranges:
U+002b0 - U+002c1
U+0060c - U+0060d
U+0061e - U+00612
U+0064b - U+0065e
U+0074d - U+0076d
U+01800 - U+01805
U+01d00 - U+01d77
U+01d9b - U+01dbf
U+0200b - U+0200f
U+030fc - U+030fe
U+03260 - U+0327f
U+0fb46 - U+0fbb1
U+10450 - U+1049d
12. The -o option (show only the matching part of a line) for pcregrep was not
compatible with GNU grep in that, if there was more than one match in a
line, it showed only the first of them. It now behaves in the same way as
GNU grep.
13. If the -o and -v options were combined for pcregrep, it printed a blank
line for every non-matching line. GNU grep prints nothing, and pcregrep now
does the same. The return code can be used to tell if there were any
non-matching lines.
14. Added --file-offsets and --line-offsets to pcregrep.
15. The pattern (?=something)(?R) was not being diagnosed as a potentially
infinitely looping recursion. The bug was that positive lookaheads were not
being skipped when checking for a possible empty match (negative lookaheads
and both kinds of lookbehind were skipped).
16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
inclusion of <windows.h> to before rather than after the definition of
INVALID_FILE_ATTRIBUTES (patch from David Byron).
17. Specifying a possessive quantifier with a specific limit for a Unicode
character property caused pcre_compile() to compile bad code, which led at
runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
caused the error; without that there was no problem.
18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
19. Added --enable-pcretest-libreadline.
20. In pcrecpp.cc, the variable 'count' was incremented twice in
RE::GlobalReplace(). As a result, the number of replacements returned was
double what it should be. I removed one of the increments, but Craig sent a
later patch that removed the other one (the right fix) and added unit tests
that check the return values (which was not done before).
21. Several CMake things:
(1) Arranged that, when cmake is used on Unix, the libraries end up with
the names libpcre and libpcreposix, not just pcre and pcreposix.
(2) The above change means that pcretest and pcregrep are now correctly