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authordartraiden <wowemuh@gmail.com>2018-06-01 18:25:57 +0300
committerdartraiden <wowemuh@gmail.com>2018-06-01 18:26:31 +0300
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-ChangeLog for PCRE
-------------------
-
-Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
-development is happening in the PCRE2 10.xx series.
-
-
-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 Fixed outdated real_pcre definitions in pcre.h.in (patch by Evgeny Kotkov).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
-PCRE_STATIC_RUNTIME (affects MSVC only).
-
-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
-Pisar).
-
-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
- [\W\pL].
-
-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
- \x{ff}.
-
-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
- afl-fuzz.
-
-16. An invalid pattern fragment such as (?(?C)0 was not diagnosing an error
- ("assertion expected") when (?(?C) was not followed by an opening
- parenthesis.
-
-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
- fuzzer.
-
-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
- string.
-
-25. If (?R was followed by - or + incorrect behaviour happened instead of a
- diagnostic.
-
-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
- fuzzer.
-
-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
- fuzzer.
-
-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,
- zero).
-
-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
- pattern.
-
- (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
- string.
-
-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
- CVE-2015-2325.
-
-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
- optimization.
-
-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
- fuzzer.
-
-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:
-
- '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
- NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
-
- 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
- doesn't).
-
-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:
-
- /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
-
- 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
- bracket.
-
-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
- compiler.
-
-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
- pcretest.
-
-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
- start.
-
-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
- before.
-
-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
- unambiguous.
-
-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
- attributes.
-
- 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
- improvements.
-
-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
- Names.
-
-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
- ignored.
-
-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
- interpreter.
-
-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
- *PRUNE or *SKIP.
-
-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
- grep:
-
- (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
- set.
-
-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
- information.
-
- (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
- pcre_exec().
-
-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
- references.
-
- (b) \R did not give a hard partial match if \r was found at the end of the
- subject.
-
- (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.)
-
-11. Add PCRE_INFO_MAXLOOKBEHIND.
-
-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
- call.
-
-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
- libreadline.
-
-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
- assertions.
-
-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
- -lreadline.
-
-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
- tested.
-
-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
- systems.
-
-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
- complain.
-
-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
- case.
-
-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
- returned.
-
-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
- environments.
-
-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
- left).
-
-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
- correctly.
-
-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
- match.
-
-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
- Perl).
-
-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"
- twice.
-
-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
- match.
-
-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
- (*THEN).
-
-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
- pcre_compile().
-
-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
- THEN.
-
-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
- (#976).
-
-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
- altogether.)
-
-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
- configured.
-
-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
- string.
-
-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
- decrease.
-
-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
- PCRE_ERROR_DFA_UITEM.
-
-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
- module.
-
-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
- double.
-
-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
- page.
-
-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
- used.
-
-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
- USPTR.
-
-16. GNU libtool is named differently on some systems. The autogen.sh script now
- tries several variants such as glibtoolize (MacOSX) and libtoolize1x
- (FreeBSD).
-
-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
- error.
-
-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
- result.
-
-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
- PCRE_ERROR_PARTIAL is returned.
-
-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
- library.
-
-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
- pcre_fullinfo().
-
-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
- 8.33.]
-
-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++
- wrapper.
-
-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
- pre-defined.
-
-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
- scripts.
-
-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
- truncation.
-
-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
- Lopes.
-
-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
- time.
-
-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
- (*FAIL).
-
-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 Bergström.
-
-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
- overflow.
-
-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
- HAVE_LONG_LONG.
- - 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
- Configure/Make.
-
-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
- included.
-
-3. The same bug as (2) above applied to negated POSIX classes such as
- [:^space:].
-
-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
- "backspace".
-
-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
- linked with the newly-built libraries, not previously installed ones.
-
- (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
-
-22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
- crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
- UTF-8 newline character). The key issue is that the pattern starts .*;
- this means that the match must be either at the beginning, or after a
- newline. The bug was in the code for advancing after a failed match and
- checking that the new position followed a newline. It was not taking
- account of UTF-8 characters correctly.
-
-23. PCRE was behaving differently from Perl in the way it recognized POSIX
- character classes. PCRE was not treating the sequence [:...:] as a
- character class unless the ... were all letters. Perl, however, seems to
- allow any characters between [: and :], though of course it rejects as
- unknown any "names" that contain non-letters, because all the known class
- names consist only of letters. Thus, Perl gives an error for [[:1234:]],
- for example, whereas PCRE did not - it did not recognize a POSIX character
- class. This seemed a bit dangerous, so the code has been changed to be
- closer to Perl. The behaviour is not identical to Perl, because PCRE will
- diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
- treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
- Perl does, and where it didn't before.
-
-24. Rewrite so as to remove the single use of %n from pcregrep because in some
- Windows environments %n is disabled by default.
-
-
-Version 7.4 21-Sep-07
----------------------
-
-1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
- means that a class such as [\s] counted as "explicit reference to CR or
- LF". That isn't really right - the whole point of the change was to try to
- help when there was an actual mention of one of the two characters. So now
- the change happens only if \r or \n (or a literal CR or LF) character is
- encountered.
-
-2. The 32-bit options word was also used for 6 internal flags, but the numbers
- of both had grown to the point where there were only 3 bits left.
- Fortunately, there was spare space in the data structure, and so I have
- moved the internal flags into a new 16-bit field to free up more option
- bits.
-
-3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
- but did not set the internal JCHANGED flag - either of these is enough to
- control the way the "get" function works - but the PCRE_INFO_JCHANGED
- facility is supposed to tell if (?J) was ever used, so now (?J) at the
- start sets both bits.
-
-4. Added options (at build time, compile time, exec time) to change \R from
- matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
-
-5. doc/pcresyntax.html was missing from the distribution.
-
-6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
- compatibility, even though it is no longer used.
-
-7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
- strtoull to pcrecpp.cc to select the available functions in WIN32 when the
- windows.h file is present (where different names are used). [This was
- reversed later after testing - see 16 below.]
-
-8. Changed all #include <config.h> to #include "config.h". There were also
- some further <pcre.h> cases that I changed to "pcre.h".
-
-9. When pcregrep was used with the --colour option, it missed the line ending
- sequence off the lines that it output.
-
-10. It was pointed out to me that arrays of string pointers cause lots of
- relocations when a shared library is dynamically loaded. A technique of
- using a single long string with a table of offsets can drastically reduce
- these. I have refactored PCRE in four places to do this. The result is
- dramatic:
-
- Originally: 290
- After changing UCP table: 187
- After changing error message table: 43
- After changing table of "verbs" 36
- After changing table of Posix names 22
-
- Thanks to the folks working on Gregex for glib for this insight.
-
-11. --disable-stack-for-recursion caused compiling to fail unless -enable-
- unicode-properties was also set.
-
-12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
-
-13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
- checked only for CRLF.
-
-14. Added casts to pcretest.c to avoid compiler warnings.
-
-15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
-
-16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
- and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
- entirely. This removes changes made in 7 above.
-
-17. The CMake files have been updated, and there is now more information about
- building with CMake in the NON-UNIX-USE document.
-
-
-Version 7.3 28-Aug-07
----------------------
-
- 1. In the rejigging of the build system that eventually resulted in 7.1, the
- line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
- brackets there is not right, since it causes compilers to look for an
- installed pcre.h, not the version that is in the source that is being
- compiled (which of course may be different). I have changed it back to:
-
- #include "pcre.h"
-
- I have a vague recollection that the change was concerned with compiling in
- different directories, but in the new build system, that is taken care of
- by the VPATH setting the Makefile.
-
- 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
- when the subject happened to end in the byte 0x85 (e.g. if the last
- character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
- characters but of course it shouldn't be taken as a newline when it is part
- of another character. The bug was that, for an unlimited repeat of . in
- not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
- characters when looking for a newline.
-
- 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
-
- 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
- in debug output.
-
- 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
- long printing in the pcrecpp unittest when running under MinGW.
-
- 6. ESC_K was left out of the EBCDIC table.
-
- 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
- parentheses; I made it 1000, which seemed large enough. Unfortunately, the
- limit also applies to "virtual nesting" when a pattern is recursive, and in
- this case 1000 isn't so big. I have been able to remove this limit at the
- expense of backing off one optimization in certain circumstances. Normally,
- when pcre_exec() would call its internal match() function recursively and
- immediately return the result unconditionally, it uses a "tail recursion"
- feature to save stack. However, when a subpattern that can match an empty
- string has an unlimited repetition quantifier, it no longer makes this
- optimization. That gives it a stack frame in which to save the data for
- checking that an empty string has been matched. Previously this was taken
- from the 1000-entry workspace that had been reserved. So now there is no
- explicit limit, but more stack is used.
-
- 8. Applied Daniel's patches to solve problems with the import/export magic
- syntax that is required for Windows, and which was going wrong for the
- pcreposix and pcrecpp parts of the library. These were overlooked when this
- problem was solved for the main library.
-
- 9. There were some crude static tests to avoid integer overflow when computing
- the size of patterns that contain repeated groups with explicit upper
- limits. As the maximum quantifier is 65535, the maximum group length was
- set at 30,000 so that the product of these two numbers did not overflow a
- 32-bit integer. However, it turns out that people want to use groups that
- are longer than 30,000 bytes (though not repeat them that many times).
- Change 7.0/17 (the refactoring of the way the pattern size is computed) has
- made it possible to implement the integer overflow checks in a much more
- dynamic way, which I have now done. The artificial limitation on group
- length has been removed - we now have only the limit on the total length of
- the compiled pattern, which depends on the LINK_SIZE setting.
-
-10. Fixed a bug in the documentation for get/copy named substring when
- duplicate names are permitted. If none of the named substrings are set, the
- functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
- empty string.
-
-11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
- instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
- because the ] is interpreted as the first data character and the
- terminating ] is not found. PCRE has been made compatible with Perl in this
- regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
- cause memory overwriting.
-
-10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
- string has been matched (to stop an infinite loop). It was not recognizing
- a conditional subpattern that could match an empty string if that
- subpattern was within another subpattern. For example, it looped when
- trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
- condition was not nested. This bug has been fixed.
-
-12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
- past the start of the subject in the presence of bytes with the top bit
- set, for example "\x8aBCD".
-
-13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
- (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
-
-14. Optimized (?!) to (*FAIL).
-
-15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
- This restricts code points to be within the range 0 to 0x10FFFF, excluding
- the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
- full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
- does: it's just the validity check that is more restrictive.
-
-16. Inserted checks for integer overflows during escape sequence (backslash)
- processing, and also fixed erroneous offset values for syntax errors during
- backslash processing.
-
-17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
- for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
-
-18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
- caused an overrun.
-
-19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
- something other than just ASCII characters) inside a group that had an
- unlimited repeat caused a loop at compile time (while checking to see
- whether the group could match an empty string).
-
-20. Debugging a pattern containing \p or \P could cause a crash. For example,
- [\P{Any}] did so. (Error in the code for printing property names.)
-
-21. An orphan \E inside a character class could cause a crash.
-
-22. A repeated capturing bracket such as (A)? could cause a wild memory
- reference during compilation.
-
-23. There are several functions in pcre_compile() that scan along a compiled
- expression for various reasons (e.g. to see if it's fixed length for look
- behind). There were bugs in these functions when a repeated \p or \P was
- present in the pattern. These operators have additional parameters compared
- with \d, etc, and these were not being taken into account when moving along
- the compiled data. Specifically:
-
- (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
- length.
-
- (b) An item such as \pL+ within a repeated group could cause crashes or
- loops.
-
- (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
- "reference to non-existent subpattern" error.
-
- (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
-
-24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
- characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
-
-25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
-
-26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
- character were causing crashes (broken optimization).
-
-27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
- \p or \P) caused a compile-time loop.
-
-28. More problems have arisen in unanchored patterns when CRLF is a valid line
- break. For example, the unstudied pattern [\r\n]A does not match the string
- "\r\nA" because change 7.0/46 below moves the current point on by two
- characters after failing to match at the start. However, the pattern \nA
- *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
- the same is true. There doesn't seem any very clean way out of this, but
- what I have chosen to do makes the common cases work: PCRE now takes note
- of whether there can be an explicit match for \r or \n anywhere in the
- pattern, and if so, 7.0/46 no longer applies. As part of this change,
- there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
- pattern has explicit CR or LF references.
-
-29. Added (*CR) etc for changing newline setting at start of pattern.
-
-
-Version 7.2 19-Jun-07
----------------------
-
- 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
- which is apparently normally available under Windows.
-
- 2. Re-jig the pcregrep tests with different newline settings in an attempt
- to make them independent of the local environment's newline setting.
-
- 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
-
- 4. Some of the "internals" tests were previously cut out when the link size
- was not 2, because the output contained actual offsets. The recent new
- "Z" feature of pcretest means that these can be cut out, making the tests
- usable with all link sizes.
-
- 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
- stack recursion. This gives a massive performance boost under BSD, but just
- a small improvement under Linux. However, it saves one field in the frame
- in all cases.
-
- 6. Added more features from the forthcoming Perl 5.10:
-
- (a) (?-n) (where n is a string of digits) is a relative subroutine or
- recursion call. It refers to the nth most recently opened parentheses.
-
- (b) (?+n) is also a relative subroutine call; it refers to the nth next
- to be opened parentheses.
-
- (c) Conditions that refer to capturing parentheses can be specified
- relatively, for example, (?(-2)... or (?(+3)...
-
- (d) \K resets the start of the current match so that everything before
- is not part of it.
-
- (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
-
- (f) \g{name} is another synonym - part of Perl 5.10's unification of
- reference syntax.
-
- (g) (?| introduces a group in which the numbering of parentheses in each
- alternative starts with the same number.
-
- (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
-
- 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
- PCRE_INFO_JCHANGED.
-
- 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
- terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
- for detecting groups that can match an empty string.
-
- 9. A pattern with a very large number of alternatives (more than several
- hundred) was running out of internal workspace during the pre-compile
- phase, where pcre_compile() figures out how much memory will be needed. A
- bit of new cunning has reduced the workspace needed for groups with
- alternatives. The 1000-alternative test pattern now uses 12 bytes of
- workspace instead of running out of the 4096 that are available.
-
-10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
-
-11. Applied patch from Google to remove an optimization that didn't quite work.
- The report of the bug said:
-
- pcrecpp::RE("a*").FullMatch("aaa") matches, while
- pcrecpp::RE("a*?").FullMatch("aaa") does not, and
- pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
-
-12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
- it matched the wrong number of bytes.
-
-
-Version 7.1 24-Apr-07
----------------------
-
- 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
- that is more "standard", making use of automake and other Autotools. There
- is some re-arrangement of the files and adjustment of comments consequent
- on this.
-
- 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
- for recursive directory scanning broke on some systems because the files
- are not scanned in any specific order and on different systems the order
- was different. A call to "sort" has been inserted into RunGrepTest for the
- approprate test as a short-term fix. In the longer term there may be an
- alternative.
-
- 3. I had an email from Eric Raymond about problems translating some of PCRE's
- man pages to HTML (despite the fact that I distribute HTML pages, some
- people do their own conversions for various reasons). The problems
- concerned the use of low-level troff macros .br and .in. I have therefore
- removed all such uses from the man pages (some were redundant, some could
- be replaced by .nf/.fi pairs). The 132html script that I use to generate
- HTML has been updated to handle .nf/.fi and to complain if it encounters
- .br or .in.
-
- 4. Updated comments in configure.ac that get placed in config.h.in and also
- arranged for config.h to be included in the distribution, with the name
- config.h.generic, for the benefit of those who have to compile without
- Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
-
- 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
- Weber: (1) pcre_internal.h was missing some function renames; (2) updated
- makevp.bat for the current PCRE, using the additional files
- makevp_c.txt, makevp_l.txt, and pcregexp.pas.
-
- 6. A Windows user reported a minor discrepancy with test 2, which turned out
- to be caused by a trailing space on an input line that had got lost in his
- copy. The trailing space was an accident, so I've just removed it.
-
- 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
- that is needed.
-
- 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
- as "const" (a) because they are and (b) because it helps the PHP
- maintainers who have recently made a script to detect big data structures
- in the php code that should be moved to the .rodata section. I remembered
- to update Builducptable as well, so it won't revert if ucptable.h is ever
- re-created.
-
- 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
- pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
- order to be able to cut out the UTF-8 tables in the latter when UTF-8
- support is not required. This saves 1.5-2K of code, which is important in
- some applications.
-
- Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
- so as not to refer to the tables, even though these functions will never be
- called when UTF-8 support is disabled. Otherwise there are problems with a
- shared library.
-
-10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
-
- (a) It was defining its arguments as char * instead of void *.
-
- (b) It was assuming that all moves were upwards in memory; this was true
- a long time ago when I wrote it, but is no longer the case.
-
- The emulated memove() is provided for those environments that have neither
- memmove() nor bcopy(). I didn't think anyone used it these days, but that
- is clearly not the case, as these two bugs were recently reported.
-
-11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
- and Detrail to create the HTML documentation, the .txt form of the man
- pages, and it removes trailing spaces from listed files. It also creates
- pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
- case, it wraps all the #defines with #ifndefs. This script should be run
- before "make dist".
-
-12. Fixed two fairly obscure bugs concerned with quantified caseless matching
- with Unicode property support.
-
- (a) For a maximizing quantifier, if the two different cases of the
- character were of different lengths in their UTF-8 codings (there are
- some cases like this - I found 11), and the matching function had to
- back up over a mixture of the two cases, it incorrectly assumed they
- were both the same length.
-
- (b) When PCRE was configured to use the heap rather than the stack for
- recursion during matching, it was not correctly preserving the data for
- the other case of a UTF-8 character when checking ahead for a match
- while processing a minimizing repeat. If the check also involved
- matching a wide character, but failed, corruption could cause an
- erroneous result when trying to check for a repeat of the original
- character.
-
-13. Some tidying changes to the testing mechanism:
-
- (a) The RunTest script now detects the internal link size and whether there
- is UTF-8 and UCP support by running ./pcretest -C instead of relying on
- values substituted by "configure". (The RunGrepTest script already did
- this for UTF-8.) The configure.ac script no longer substitutes the
- relevant variables.
-
- (b) The debugging options /B and /D in pcretest show the compiled bytecode
- with length and offset values. This means that the output is different
- for different internal link sizes. Test 2 is skipped for link sizes
- other than 2 because of this, bypassing the problem. Unfortunately,
- there was also a test in test 3 (the locale tests) that used /B and
- failed for link sizes other than 2. Rather than cut the whole test out,
- I have added a new /Z option to pcretest that replaces the length and
- offset values with spaces. This is now used to make test 3 independent
- of link size. (Test 2 will be tidied up later.)
-
-14. If erroroffset was passed as NULL to pcre_compile, it provoked a
- segmentation fault instead of returning the appropriate error message.
-
-15. In multiline mode when the newline sequence was set to "any", the pattern
- ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
- This doesn't seem right; it now treats the CRLF combination as the line
- ending, and so does not match in that case. It's only a pattern such as ^$
- that would hit this one: something like ^ABC$ would have failed after \r
- and then tried again after \r\n.
-
-16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
- in an attempt to make files that differ only in their line terminators
- compare equal. This works on Linux.
-
-17. Under certain error circumstances pcregrep might try to free random memory
- as it exited. This is now fixed, thanks to valgrind.
-
-19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
- "abc\r\n\r\n", it found an unwanted second match after the second \r. This
- was because its rules for how to advance for /g after matching an empty
- string at the end of a line did not allow for this case. They now check for
- it specially.
-
-20. pcretest is supposed to handle patterns and data of any length, by
- extending its buffers when necessary. It was getting this wrong when the
- buffer for a data line had to be extended.
-
-21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
- CRLF as a newline sequence.
-
-22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
- out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
- I have nevertheless tidied it up.
-
-23. Added some casts to kill warnings from HP-UX ia64 compiler.
-
-24. Added a man page for pcre-config.
-
-
-Version 7.0 19-Dec-06
----------------------
-
- 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
- moving to gcc 4.1.1.
-
- 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
- sys/time.h, which is documented as needed for this function. It doesn't
- seem to matter on Linux, but it showed up on some releases of OS X.
-
- 3. It seems that there are systems where bytes whose values are greater than
- 127 match isprint() in the "C" locale. The "C" locale should be the
- default when a C program starts up. In most systems, only ASCII printing
- characters match isprint(). This difference caused the output from pcretest
- to vary, making some of the tests fail. I have changed pcretest so that:
-
- (a) When it is outputting text in the compiled version of a pattern, bytes
- other than 32-126 are always shown as hex escapes.
-
- (b) When it is outputting text that is a matched part of a subject string,
- it does the same, unless a different locale has been set for the match
- (using the /L modifier). In this case, it uses isprint() to decide.
-
- 4. Fixed a major bug that caused incorrect computation of the amount of memory
- required for a compiled pattern when options that changed within the
- pattern affected the logic of the preliminary scan that determines the
- length. The relevant options are -x, and -i in UTF-8 mode. The result was
- that the computed length was too small. The symptoms of this bug were
- either the PCRE error "internal error: code overflow" from pcre_compile(),
- or a glibc crash with a message such as "pcretest: free(): invalid next
- size (fast)". Examples of patterns that provoked this bug (shown in
- pcretest format) are:
-
- /(?-x: )/x
- /(?x)(?-x: \s*#\s*)/
- /((?i)[\x{c0}])/8
- /(?i:[\x{c0}])/8
-
- HOWEVER: Change 17 below makes this fix obsolete as the memory computation
- is now done differently.
-
- 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
- wrapper classes; (b) implement a new function in the C++ scanner that is
- more efficient than the old way of doing things because it avoids levels of
- recursion in the regex matching; (c) add a paragraph to the documentation
- for the FullMatch() function.
-
- 6. The escape sequence \n was being treated as whatever was defined as
- "newline". Not only was this contrary to the documentation, which states
- that \n is character 10 (hex 0A), but it also went horribly wrong when
- "newline" was defined as CRLF. This has been fixed.
-
- 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
- was being set to -1 for the "end of line" case (supposedly a value that no
- character can have). Though this value is never used (the check for end of
- line is "zero bytes in current character"), it caused compiler complaints.
- I've changed it to 0xffffffff.
-
- 8. In pcre_version.c, the version string was being built by a sequence of
- C macros that, in the event of PCRE_PRERELEASE being defined as an empty
- string (as it is for production releases) called a macro with an empty
- argument. The C standard says the result of this is undefined. The gcc
- compiler treats it as an empty string (which was what was wanted) but it is
- reported that Visual C gives an error. The source has been hacked around to
- avoid this problem.
-
- 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
- builds of pcretest, and changed the call to _setmode() to use _O_BINARY
- instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
- of them did).
-
-10. Originally, pcretest opened its input and output without "b"; then I was
- told that "b" was needed in some environments, so it was added for release
- 5.0 to both the input and output. (It makes no difference on Unix-like
- systems.) Later I was told that it is wrong for the input on Windows. I've
- now abstracted the modes into two macros, to make it easier to fiddle with
- them, and removed "b" from the input mode under Windows.
-
-11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
-
-12. Added -help and --help to pcretest as an official way of being reminded
- of the options.
-
-13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
- and pcrecpp.cc because they annoy compilers at high warning levels.
-
-14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
-
-15. Fixed an occurrence of == in configure.ac that should have been = (shell
- scripts are not C programs :-) and which was not noticed because it works
- on Linux.
-
-16. pcretest is supposed to handle any length of pattern and data line (as one
- line or as a continued sequence of lines) by extending its input buffer if
- necessary. This feature was broken for very long pattern lines, leading to
- a string of junk being passed to pcre_compile() if the pattern was longer
- than about 50K.
-
-17. I have done a major re-factoring of the way pcre_compile() computes the
- amount of memory needed for a compiled pattern. Previously, there was code
- that made a preliminary scan of the pattern in order to do this. That was
- OK when PCRE was new, but as the facilities have expanded, it has become
- harder and harder to keep it in step with the real compile phase, and there
- have been a number of bugs (see for example, 4 above). I have now found a
- cunning way of running the real compile function in a "fake" mode that
- enables it to compute how much memory it would need, while actually only
- ever using a few hundred bytes of working memory and without too many
- tests of the mode. This should make future maintenance and development
- easier. A side effect of this work is that the limit of 200 on the nesting
- depth of parentheses has been removed (though this was never a serious
- limitation, I suspect). However, there is a downside: pcre_compile() now
- runs more slowly than before (30% or more, depending on the pattern). I
- hope this isn't a big issue. There is no effect on runtime performance.
-
-18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
- newline (only possible for the last line of a file) and it was a
- pattern that set a locale (followed by /Lsomething), pcretest crashed.
-
-19. Added additional timing features to pcretest. (1) The -tm option now times
- matching only, not compiling. (2) Both -t and -tm can be followed, as a
- separate command line item, by a number that specifies the number of
- repeats to use when timing. The default is 50000; this gives better
- precision, but takes uncomfortably long for very large patterns.
-
-20. Extended pcre_study() to be more clever in cases where a branch of a
- subpattern has no definite first character. For example, (a*|b*)[cd] would
- previously give no result from pcre_study(). Now it recognizes that the
- first character must be a, b, c, or d.
-
-21. There was an incorrect error "recursive call could loop indefinitely" if
- a subpattern (or the entire pattern) that was being tested for matching an
- empty string contained only one non-empty item after a nested subpattern.
- For example, the pattern (?>\x{100}*)\d(?R) provoked this error
- incorrectly, because the \d was being skipped in the check.
-
-22. The pcretest program now has a new pattern option /B and a command line
- option -b, which is equivalent to adding /B to every pattern. This causes
- it to show the compiled bytecode, without the additional information that
- -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
- is the same as /B/I).
-
-23. A new optimization is now able automatically to treat some sequences such
- as a*b as a*+b. More specifically, if something simple (such as a character
- or a simple class like \d) has an unlimited quantifier, and is followed by
- something that cannot possibly match the quantified thing, the quantifier
- is automatically "possessified".
-
-24. A recursive reference to a subpattern whose number was greater than 39
- went wrong under certain circumstances in UTF-8 mode. This bug could also
- have affected the operation of pcre_study().
-
-25. Realized that a little bit of performance could be had by replacing
- (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
-
-26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
-
-27. Possessive quantifiers such as a++ were previously implemented by turning
- them into atomic groups such as ($>a+). Now they have their own opcodes,
- which improves performance. This includes the automatically created ones
- from 23 above.
-
-28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
- lookahead was broken if it was not anchored. PCRE was mistakenly expecting
- the first matched character to be a colon. This applied both to named and
- numbered groups.
-
-29. The ucpinternal.h header file was missing its idempotency #ifdef.
-
-30. I was sent a "project" file called libpcre.a.dev which I understand makes
- building PCRE on Windows easier, so I have included it in the distribution.
-
-31. There is now a check in pcretest against a ridiculously large number being
- returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
- loop, the loop is abandoned.
-
-32. Forward references to subpatterns in conditions such as (?(2)...) where
- subpattern 2 is defined later cause pcre_compile() to search forwards in
- the pattern for the relevant set of parentheses. This search went wrong
- when there were unescaped parentheses in a character class, parentheses
- escaped with \Q...\E, or parentheses in a #-comment in /x mode.
-
-33. "Subroutine" calls and backreferences were previously restricted to
- referencing subpatterns earlier in the regex. This restriction has now
- been removed.
-
-34. Added a number of extra features that are going to be in Perl 5.10. On the
- whole, these are just syntactic alternatives for features that PCRE had
- previously implemented using the Python syntax or my own invention. The
- other formats are all retained for compatibility.
-
- (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
- as (?P<name>...). The new forms, as well as being in Perl 5.10, are
- also .NET compatible.
-
- (b) A recursion or subroutine call to a named group can now be defined as
- (?&name) as well as (?P>name).
-
- (c) A backreference to a named group can now be defined as \k<name> or
- \k'name' as well as (?P=name). The new forms, as well as being in Perl
- 5.10, are also .NET compatible.
-
- (d) A conditional reference to a named group can now use the syntax
- (?(<name>) or (?('name') as well as (?(name).
-
- (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
- groups (named and numbered) that are never evaluated inline, but can be
- called as "subroutines" from elsewhere. In effect, the DEFINE condition
- is always false. There may be only one alternative in such a group.
-
- (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
- as the simple (?(R). The condition is true only if the most recent
- recursion is that of the given number or name. It does not search out
- through the entire recursion stack.
-
- (g) The escape \gN or \g{N} has been added, where N is a positive or
- negative number, specifying an absolute or relative reference.
-
-35. Tidied to get rid of some further signed/unsigned compiler warnings and
- some "unreachable code" warnings.
-
-36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
- things, this adds five new scripts.
-
-37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
- There were also incompatibilities regarding the handling of \Q..\E inside
- character classes, for example with patterns like [\Qa\E-\Qz\E] where the
- hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
-
-38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
- matches an empty string, and forcibly breaks the loop. There were bugs in
- this code in non-simple cases. For a pattern such as ^(a()*)* matched
- against aaaa the result was just "a" rather than "aaaa", for example. Two
- separate and independent bugs (that affected different cases) have been
- fixed.
-
-39. Refactored the code to abolish the use of different opcodes for small
- capturing bracket numbers. This is a tidy that I avoided doing when I
- removed the limit on the number of capturing brackets for 3.5 back in 2001.
- The new approach is not only tidier, it makes it possible to reduce the
- memory needed to fix the previous bug (38).
-
-40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
- sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
- processing dot, circumflex, or dollar metacharacters, or #-comments in /x
- mode.
-
-41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
- report.
-
-42. Applied patch, originally from Ari Pollak, modified by Google, to allow
- copy construction and assignment in the C++ wrapper.
-
-43. Updated pcregrep to support "--newline=any". In the process, I fixed a
- couple of bugs that could have given wrong results in the "--newline=crlf"
- case.
-
-44. Added a number of casts and did some reorganization of signed/unsigned int
- variables following suggestions from Dair Grant. Also renamed the variable
- "this" as "item" because it is a C++ keyword.
-
-45. Arranged for dftables to add
-
- #include "pcre_internal.h"
-
- to pcre_chartables.c because without it, gcc 4.x may remove the array
- definition from the final binary if PCRE is built into a static library and
- dead code stripping is activated.
-
-46. For an unanchored pattern, if a match attempt fails at the start of a
- newline sequence, and the newline setting is CRLF or ANY, and the next two
- characters are CRLF, advance by two characters instead of one.
-
-
-Version 6.7 04-Jul-06
----------------------
-
- 1. In order to handle tests when input lines are enormously long, pcretest has
- been re-factored so that it automatically extends its buffers when
- necessary. The code is crude, but this _is_ just a test program. The
- default size has been increased from 32K to 50K.
-
- 2. The code in pcre_study() was using the value of the re argument before
- testing it for NULL. (Of course, in any sensible call of the function, it
- won't be NULL.)
-
- 3. The memmove() emulation function in pcre_internal.h, which is used on
- systems that lack both memmove() and bcopy() - that is, hardly ever -
- was missing a "static" storage class specifier.
-
- 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
- containing an extended class (one that cannot be represented by a bitmap
- because it contains high-valued characters or Unicode property items, e.g.
- [\pZ]). Almost always one would set UTF-8 mode when processing such a
- pattern, but PCRE should not loop if you do not (it no longer does).
- [Detail: two cases were found: (a) a repeated subpattern containing an
- extended class; (b) a recursive reference to a subpattern that followed a
- previous extended class. It wasn't skipping over the extended class
- correctly when UTF-8 mode was not set.]
-
- 5. A negated single-character class was not being recognized as fixed-length
- in lookbehind assertions such as (?<=[^f]), leading to an incorrect
- compile error "lookbehind assertion is not fixed length".
-
- 6. The RunPerlTest auxiliary script was showing an unexpected difference
- between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
- write a Perl script that can interpret lines of an input file either as
- byte characters or as UTF-8, which is what "perltest" was being required to
- do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
- can't do is switch easily at run time between having the "use utf8;" pragma
- or not. In the end, I fudged it by using the RunPerlTest script to insert
- "use utf8;" explicitly for the UTF-8 tests.
-
- 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
- the end of the subject string, contrary to the documentation and to what
- Perl does. This was true of both matching functions. Now it matches only at
- the start of the subject and immediately after *internal* newlines.
-
- 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
- a pointer to an int instead of a pointer to an unsigned long int. This
- caused problems on 64-bit systems.
-
- 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
- instance of the 'standard' template library not being so standard".
-
-10. There was no check on the number of named subpatterns nor the maximum
- length of a subpattern name. The product of these values is used to compute
- the size of the memory block for a compiled pattern. By supplying a very
- long subpattern name and a large number of named subpatterns, the size
- computation could be caused to overflow. This is now prevented by limiting
- the length of names to 32 characters, and the number of named subpatterns
- to 10,000.
-
-11. Subpatterns that are repeated with specific counts have to be replicated in
- the compiled pattern. The size of memory for this was computed from the
- length of the subpattern and the repeat count. The latter is limited to
- 65535, but there was no limit on the former, meaning that integer overflow
- could in principle occur. The compiled length of a repeated subpattern is
- now limited to 30,000 bytes in order to prevent this.
-
-12. Added the optional facility to have named substrings with the same name.
-
-13. Added the ability to use a named substring as a condition, using the
- Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
- are numbers (not recommended). Forward references are permitted.
-
-14. Added forward references in named backreferences (if you see what I mean).
-
-15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
- pattern could run off the end of the subject. For example, the pattern
- "(?s)(.{1,5})"8 did this with the subject "ab".
-
-16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
- PCRE_CASELESS was set when matching characters that were quantified with ?
- or *.
-
-17. A character class other than a single negated character that had a minimum
- but no maximum quantifier - for example [ab]{6,} - was not handled
- correctly by pce_dfa_exec(). It would match only one character.
-
-18. A valid (though odd) pattern that looked like a POSIX character
- class but used an invalid character after [ (for example [[,abc,]]) caused
- pcre_compile() to give the error "Failed: internal error: code overflow" or
- in some cases to crash with a glibc free() error. This could even happen if
- the pattern terminated after [[ but there just happened to be a sequence of
- letters, a binary zero, and a closing ] in the memory that followed.
-
-19. Perl's treatment of octal escapes in the range \400 to \777 has changed
- over the years. Originally (before any Unicode support), just the bottom 8
- bits were taken. Thus, for example, \500 really meant \100. Nowadays the
- output from "man perlunicode" includes this:
-
- The regular expression compiler produces polymorphic opcodes. That
- is, the pattern adapts to the data and automatically switches to
- the Unicode character scheme when presented with Unicode data--or
- instead uses a traditional byte scheme when presented with byte
- data.
-
- Sadly, a wide octal escape does not cause a switch, and in a string with
- no other multibyte characters, these octal escapes are treated as before.
- Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
- /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
- Unicode string.
-
- I have not perpetrated such confusion in PCRE. Up till now, it took just
- the bottom 8 bits, as in old Perl. I have now made octal escapes with
- values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
- translate to the appropriate multibyte character.
-
-29. Applied some refactoring to reduce the number of warnings from Microsoft
- and Borland compilers. This has included removing the fudge introduced
- seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
- a warning about an unused variable.
-
-21. PCRE has not included VT (character 0x0b) in the set of whitespace
- characters since release 4.0, because Perl (from release 5.004) does not.
- [Or at least, is documented not to: some releases seem to be in conflict
- with the documentation.] However, when a pattern was studied with
- pcre_study() and all its branches started with \s, PCRE still included VT
- as a possible starting character. Of course, this did no harm; it just
- caused an unnecessary match attempt.
-
-22. Removed a now-redundant internal flag bit that recorded the fact that case
- dependency changed within the pattern. This was once needed for "required
- byte" processing, but is no longer used. This recovers a now-scarce options
- bit. Also moved the least significant internal flag bit to the most-
- significant bit of the word, which was not previously used (hangover from
- the days when it was an int rather than a uint) to free up another bit for
- the future.
-
-23. Added support for CRLF line endings as well as CR and LF. As well as the
- default being selectable at build time, it can now be changed at runtime
- via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
- specify that it is scanning data with non-default line endings.
-
-24. Changed the definition of CXXLINK to make it agree with the definition of
- LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
-
-25. Applied Ian Taylor's patches to avoid using another stack frame for tail
- recursions. This makes a big different to stack usage for some patterns.
-
-26. If a subpattern containing a named recursion or subroutine reference such
- as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
- the space required for the compiled pattern went wrong and gave too small a
- value. Depending on the environment, this could lead to "Failed: internal
- error: code overflow at offset 49" or "glibc detected double free or
- corruption" errors.
-
-27. Applied patches from Google (a) to support the new newline modes and (b) to
- advance over multibyte UTF-8 characters in GlobalReplace.
-
-28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
- difference for some implementation of PCRE in some Windows version.
-
-29. Added some extra testing facilities to pcretest:
-
- \q<number> in a data line sets the "match limit" value
- \Q<number> in a data line sets the "match recursion limt" value
- -S <number> sets the stack size, where <number> is in megabytes
-
- The -S option isn't available for Windows.
-
-
-Version 6.6 06-Feb-06
----------------------
-
- 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
- in pcreposix.h. I have copied the definition from pcre.h.
-
- 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
- because pcre.h is no longer a built file.
-
- 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
- not normally included in the compiled code.
-
-
-Version 6.5 01-Feb-06
----------------------
-
- 1. When using the partial match feature with pcre_dfa_exec(), it was not
- anchoring the second and subsequent partial matches at the new starting
- point. This could lead to incorrect results. For example, with the pattern
- /1234/, partially matching against "123" and then "a4" gave a match.
-
- 2. Changes to pcregrep:
-
- (a) All non-match returns from pcre_exec() were being treated as failures
- to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
- error message is output. Some extra information is given for the
- PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
- probably the only errors that are likely to be caused by users (by
- specifying a regex that has nested indefinite repeats, for instance).
- If there are more than 20 of these errors, pcregrep is abandoned.
-
- (b) A binary zero was treated as data while matching, but terminated the
- output line if it was written out. This has been fixed: binary zeroes
- are now no different to any other data bytes.
-
- (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
- used to set a locale for matching. The --locale=xxxx long option has
- been added (no short equivalent) to specify a locale explicitly on the
- pcregrep command, overriding the environment variables.
-
- (d) When -B was used with -n, some line numbers in the output were one less
- than they should have been.
-
- (e) Added the -o (--only-matching) option.
-
- (f) If -A or -C was used with -c (count only), some lines of context were
- accidentally printed for the final match.
-
- (g) Added the -H (--with-filename) option.
-
- (h) The combination of options -rh failed to suppress file names for files
- that were found from directory arguments.
-
- (i) Added the -D (--devices) and -d (--directories) options.
-
- (j) Added the -F (--fixed-strings) option.
-
- (k) Allow "-" to be used as a file name for -f as well as for a data file.
-
- (l) Added the --colo(u)r option.
-
- (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
- is not present by default.
-
- 3. A nasty bug was discovered in the handling of recursive patterns, that is,
- items such as (?R) or (?1), when the recursion could match a number of
- alternatives. If it matched one of the alternatives, but subsequently,
- outside the recursion, there was a failure, the code tried to back up into
- the recursion. However, because of the way PCRE is implemented, this is not
- possible, and the result was an incorrect result from the match.
-
- In order to prevent this happening, the specification of recursion has
- been changed so that all such subpatterns are automatically treated as
- atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
-
- 4. I had overlooked the fact that, in some locales, there are characters for
- which isalpha() is true but neither isupper() nor islower() are true. In
- the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
- and ordfeminine) are like this. This affected the treatment of \w and \W
- when they appeared in character classes, but not when they appeared outside
- a character class. The bit map for "word" characters is now created
- separately from the results of isalnum() instead of just taking it from the
- upper, lower, and digit maps. (Plus the underscore character, of course.)
-
- 5. The above bug also affected the handling of POSIX character classes such as
- [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
- permanent tables. Instead, the bit maps for such a class were previously
- created as the appropriate unions of the upper, lower, and digit bitmaps.
- Now they are created by subtraction from the [[:word:]] class, which has
- its own bitmap.
-
- 6. The [[:blank:]] character class matches horizontal, but not vertical space.
- It is created by subtracting the vertical space characters (\x09, \x0a,
- \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
- subtraction was done in the overall bitmap for a character class, meaning
- that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
- be recognized. This bug has been fixed.
-
- 7. Patches from the folks at Google:
-
- (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
- real life, but is still worth protecting against".
-
- (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
- regular expressions".
-
- (c) pcre_scanner.cc: avoid use of std::count() because not all systems
- have it.
-
- (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
- "configure" and the latter not, in order to fix a problem somebody had
- with compiling the Arg class on HP-UX.
-
- (e) Improve the error-handling of the C++ wrapper a little bit.
-
- (f) New tests for checking recursion limiting.
-
- 8. The pcre_memmove() function, which is used only if the environment does not
- have a standard memmove() function (and is therefore rarely compiled),
- contained two bugs: (a) use of int instead of size_t, and (b) it was not
- returning a result (though PCRE never actually uses the result).
-
- 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
- large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
- returned instead of calling malloc() with an overflowing number that would
- most likely cause subsequent chaos.
-
-10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
-
-11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
- with this option is matched, the nmatch and pmatch options of regexec() are
- ignored.
-
-12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
- provided in case anyone wants to the the POSIX interface with UTF-8
- strings.
-
-13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
- C++ linking (needed for some HP-UX environments).
-
-14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
- (unused parameter) and in the pcre_printint() function (omitted "default"
- switch label when the default is to do nothing).
-
-15. Added some code to make it possible, when PCRE is compiled as a C++
- library, to replace subject pointers for pcre_exec() with a smart pointer
- class, thus making it possible to process discontinuous strings.
-
-16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
- much the same function. They were added by different people who were trying
- to make PCRE easy to compile on non-Unix systems. It has been suggested
- that PCRE_EXPORT be abolished now that there is more automatic apparatus
- for compiling on Windows systems. I have therefore replaced it with
- PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
- defaults to "extern" for C or "extern C" for C++, which works fine on
- Unix-like systems. It is now possible to override the value of PCRE_DATA_
- SCOPE with something explicit in config.h. In addition:
-
- (a) pcreposix.h still had just "extern" instead of either of these macros;
- I have replaced it with PCRE_DATA_SCOPE.
-
- (b) Functions such as _pcre_xclass(), which are internal to the library,
- but external in the C sense, all had PCRE_EXPORT in their definitions.
- This is apparently wrong for the Windows case, so I have removed it.
- (It makes no difference on Unix-like systems.)
-
-17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
- of recursive calls to match(). This is different to MATCH_LIMIT because
- that limits the total number of calls to match(), not all of which increase
- the depth of recursion. Limiting the recursion depth limits the amount of
- stack (or heap if NO_RECURSE is set) that is used. The default can be set
- when PCRE is compiled, and changed at run time. A patch from Google adds
- this functionality to the C++ interface.
-
-18. Changes to the handling of Unicode character properties:
-
- (a) Updated the table to Unicode 4.1.0.
-
- (b) Recognize characters that are not in the table as "Cn" (undefined).
-
- (c) I revised the way the table is implemented to a much improved format
- which includes recognition of ranges. It now supports the ranges that
- are defined in UnicodeData.txt, and it also amalgamates other
- characters into ranges. This has reduced the number of entries in the
- table from around 16,000 to around 3,000, thus reducing its size
- considerably. I realized I did not need to use a tree structure after
- all - a binary chop search is just as efficient. Having reduced the
- number of entries, I extended their size from 6 bytes to 8 bytes to
- allow for more data.
-
- (d) Added support for Unicode script names via properties such as \p{Han}.
-
-19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
- matching that character.
-
-20. When matching a repeated Unicode property with a minimum greater than zero,
- (for example \pL{2,}), PCRE could look past the end of the subject if it
- reached it while seeking the minimum number of characters. This could
- happen only if some of the characters were more than one byte long, because
- there is a check for at least the minimum number of bytes.
-
-21. Refactored the implementation of \p and \P so as to be more general, to
- allow for more different types of property in future. This has changed the
- compiled form incompatibly. Anybody with saved compiled patterns that use
- \p or \P will have to recompile them.
-
-22. Added "Any" and "L&" to the supported property types.
-
-23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
- but give a compile time error if the value is greater than 0xff.
-
-24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
- accidentally not being installed or uninstalled.
-
-25. The pcre.h file was built from pcre.h.in, but the only changes that were
- made were to insert the current release number. This seemed silly, because
- it made things harder for people building PCRE on systems that don't run
- "configure". I have turned pcre.h into a distributed file, no longer built
- by "configure", with the version identification directly included. There is
- no longer a pcre.h.in file.
-
- However, this change necessitated a change to the pcre-config script as
- well. It is built from pcre-config.in, and one of the substitutions was the
- release number. I have updated configure.ac so that ./configure now finds
- the release number by grepping pcre.h.
-
-26. Added the ability to run the tests under valgrind.
-
-
-Version 6.4 05-Sep-05
----------------------
-
- 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
- "--" to be printed when multiple files were scanned, even when none of the
- -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
- consider it to be a bug, and have restored the previous behaviour.
-
- 2. A couple of code tidies to get rid of compiler warnings.
-
- 3. The pcretest program used to cheat by referring to symbols in the library
- whose names begin with _pcre_. These are internal symbols that are not
- really supposed to be visible externally, and in some environments it is
- possible to suppress them. The cheating is now confined to including
- certain files from the library's source, which is a bit cleaner.
-
- 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
- file's purpose clearer.
-
- 5. Reorganized pcre_ucp_findchar().
-
-
-Version 6.3 15-Aug-05
----------------------
-
- 1. The file libpcre.pc.in did not have general read permission in the tarball.
-
- 2. There were some problems when building without C++ support:
-
- (a) If C++ support was not built, "make install" and "make test" still
- tried to test it.
-
- (b) There were problems when the value of CXX was explicitly set. Some
- changes have been made to try to fix these, and ...
-
- (c) --disable-cpp can now be used to explicitly disable C++ support.
-
- (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
- backslash in a target when C++ was disabled. This confuses some
- versions of "make", apparently. Using an intermediate variable solves
- this. (Same for CPP_LOBJ.)
-
- 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
- (non-Windows) now includes $(CFLAGS) because these flags are sometimes
- necessary on certain architectures.
-
- 4. Added a setting of -export-symbols-regex to the link command to remove
- those symbols that are exported in the C sense, but actually are local
- within the library, and not documented. Their names all begin with
- "_pcre_". This is not a perfect job, because (a) we have to except some
- symbols that pcretest ("illegally") uses, and (b) the facility isn't always
- available (and never for static libraries). I have made a note to try to
- find a way round (a) in the future.
-
-
-Version 6.2 01-Aug-05
----------------------
-
- 1. There was no test for integer overflow of quantifier values. A construction
- such as {1111111111111111} would give undefined results. What is worse, if
- a minimum quantifier for a parenthesized subpattern overflowed and became
- negative, the calculation of the memory size went wrong. This could have
- led to memory overwriting.
-
- 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
-
- 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
- operating environments where this matters.
-
- 4. Applied Giuseppe Maxia's patch to add additional features for controlling
- PCRE options from within the C++ wrapper.
-
- 5. Named capturing subpatterns were not being correctly counted when a pattern
- was compiled. This caused two problems: (a) If there were more than 100
- such subpatterns, the calculation of the memory needed for the whole
- compiled pattern went wrong, leading to an overflow error. (b) Numerical
- back references of the form \12, where the number was greater than 9, were
- not recognized as back references, even though there were sufficient
- previous subpatterns.
-
- 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
- versions of gcc, e.g. 2.95.4.
-
-
-Version 6.1 21-Jun-05
----------------------
-
- 1. There was one reference to the variable "posix" in pcretest.c that was not
- surrounded by "#if !defined NOPOSIX".
-
- 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
- the cross-check on the old pcre_info() function, for the benefit of the
- cut-down version of PCRE that is currently imported into Exim.
-
- 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
- allocation error. I've done the easy fix, which wastes 2 bytes for sensible
- patterns that start (?i) but I don't think that matters. The use of (?i) is
- just an example; this all applies to the other options as well.
-
- 4. Since libtool seems to echo the compile commands it is issuing, the output
- from "make" can be reduced a bit by putting "@" in front of each libtool
- compile command.
-
- 5. Patch from the folks at Google for configure.in to be a bit more thorough
- in checking for a suitable C++ installation before trying to compile the
- C++ stuff. This should fix a reported problem when a compiler was present,
- but no suitable headers.
-
- 6. The man pages all had just "PCRE" as their title. I have changed them to
- be the relevant file name. I have also arranged that these names are
- retained in the file doc/pcre.txt, which is a concatenation in text format
- of all the man pages except the little individual ones for each function.
-
- 7. The NON-UNIX-USE file had not been updated for the different set of source
- files that come with release 6. I also added a few comments about the C++
- wrapper.
-
-
-Version 6.0 07-Jun-05
----------------------
-
- 1. Some minor internal re-organization to help with my DFA experiments.
-
- 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
- didn't matter for the library itself when fully configured, but did matter
- when compiling without UCP support, or within Exim, where the ucp files are
- not imported.
-
- 3. Refactoring of the library code to split up the various functions into
- different source modules. The addition of the new DFA matching code (see
- below) to a single monolithic source would have made it really too
- unwieldy, quite apart from causing all the code to be include in a
- statically linked application, when only some functions are used. This is
- relevant even without the DFA addition now that patterns can be compiled in
- one application and matched in another.
-
- The downside of splitting up is that there have to be some external
- functions and data tables that are used internally in different modules of
- the library but which are not part of the API. These have all had their
- names changed to start with "_pcre_" so that they are unlikely to clash
- with other external names.
-
- 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
- a different (DFA) algorithm. Although it is slower than the original
- function, it does have some advantages for certain types of matching
- problem.
-
- 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
- including restarting after a partial match.
-
- 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
- defined when compiling for Windows was sent to me. I have put it into the
- code, though I have no means of testing or verifying it.
-
- 7. Added the pcre_refcount() auxiliary function.
-
- 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
- match before or at the first newline in the subject string. In pcretest,
- the /f option on a pattern can be used to set this.
-
- 9. A repeated \w when used in UTF-8 mode with characters greater than 256
- would behave wrongly. This has been present in PCRE since release 4.0.
-
-10. A number of changes to the pcregrep command:
-
- (a) Refactored how -x works; insert ^(...)$ instead of setting
- PCRE_ANCHORED and checking the length, in preparation for adding
- something similar for -w.
-
- (b) Added the -w (match as a word) option.
-
- (c) Refactored the way lines are read and buffered so as to have more
- than one at a time available.
-
- (d) Implemented a pcregrep test script.
-
- (e) Added the -M (multiline match) option. This allows patterns to match
- over several lines of the subject. The buffering ensures that at least
- 8K, or the rest of the document (whichever is the shorter) is available
- for matching (and similarly the previous 8K for lookbehind assertions).
-
- (f) Changed the --help output so that it now says
-
- -w, --word-regex(p)
-
- instead of two lines, one with "regex" and the other with "regexp"
- because that confused at least one person since the short forms are the
- same. (This required a bit of code, as the output is generated
- automatically from a table. It wasn't just a text change.)
-
- (g) -- can be used to terminate pcregrep options if the next thing isn't an
- option but starts with a hyphen. Could be a pattern or a path name
- starting with a hyphen, for instance.
-
- (h) "-" can be given as a file name to represent stdin.
-
- (i) When file names are being printed, "(standard input)" is used for
- the standard input, for compatibility with GNU grep. Previously
- "<stdin>" was used.
-
- (j) The option --label=xxx can be used to supply a name to be used for
- stdin when file names are being printed. There is no short form.
-
- (k) Re-factored the options decoding logic because we are going to add
- two more options that take data. Such options can now be given in four
- different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
-
- (l) Added the -A, -B, and -C options for requesting that lines of context
- around matches be printed.
-
- (m) Added the -L option to print the names of files that do not contain
- any matching lines, that is, the complement of -l.
-
- (n) The return code is 2 if any file cannot be opened, but pcregrep does
- continue to scan other files.
-
- (o) The -s option was incorrectly implemented. For compatibility with other
- greps, it now suppresses the error message for a non-existent or non-
- accessible file (but not the return code). There is a new option called
- -q that suppresses the output of matching lines, which was what -s was
- previously doing.
-
- (p) Added --include and --exclude options to specify files for inclusion
- and exclusion when recursing.
-
-11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
- Hopefully, it now does.
-
-12. Missing cast in pcre_study().
-
-13. Added an "uninstall" target to the makefile.
-
-14. Replaced "extern" in the function prototypes in Makefile.in with
- "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
- world, but is set differently for Windows.
-
-15. Added a second compiling function called pcre_compile2(). The only
- difference is that it has an extra argument, which is a pointer to an
- integer error code. When there is a compile-time failure, this is set
- non-zero, in addition to the error test pointer being set to point to an
- error message. The new argument may be NULL if no error number is required
- (but then you may as well call pcre_compile(), which is now just a
- wrapper). This facility is provided because some applications need a
- numeric error indication, but it has also enabled me to tidy up the way
- compile-time errors are handled in the POSIX wrapper.
-
-16. Added VPATH=.libs to the makefile; this should help when building with one
- prefix path and installing with another. (Or so I'm told by someone who
- knows more about this stuff than I do.)
-
-17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
- passes PCRE_DOTALL to the pcre_compile() function, making the "." character
- match everything, including newlines. This is not POSIX-compatible, but
- somebody wanted the feature. From pcretest it can be activated by using
- both the P and the s flags.
-
-18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
-
-19. libpcre.pc was being incorrectly installed as executable.
-
-20. A couple of places in pcretest check for end-of-line by looking for '\n';
- it now also looks for '\r' so that it will work unmodified on Windows.
-
-21. Added Google's contributed C++ wrapper to the distribution.
-
-22. Added some untidy missing memory free() calls in pcretest, to keep
- Electric Fence happy when testing.
-
-
-
-Version 5.0 13-Sep-04
----------------------
-
- 1. Internal change: literal characters are no longer packed up into items
- containing multiple characters in a single byte-string. Each character
- is now matched using a separate opcode. However, there may be more than one
- byte in the character in UTF-8 mode.
-
- 2. The pcre_callout_block structure has two new fields: pattern_position and
- next_item_length. These contain the offset in the pattern to the next match
- item, and its length, respectively.
-
- 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
- insertion of callouts before each pattern item. Added the /C option to
- pcretest to make use of this.
-
- 4. On the advice of a Windows user, the lines
-
- #if defined(_WIN32) || defined(WIN32)
- _setmode( _fileno( stdout ), 0x8000 );
- #endif /* defined(_WIN32) || defined(WIN32) */
-
- have been added to the source of pcretest. This apparently does useful
- magic in relation to line terminators.
-
- 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
- for the benefit of those environments where the "b" makes a difference.
-
- 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
- to know about it. I have put a hack into configure.in that adds in code
- to set GCC=yes if CC=icc. This seems to end up at a point in the
- generated configure script that is early enough to affect the setting of
- compiler options, which is what is needed, but I have no means of testing
- whether it really works. (The user who reported this had patched the
- generated configure script, which of course I cannot do.)
-
- LATER: After change 22 below (new libtool files), the configure script
- seems to know about icc (and also ecc). Therefore, I have commented out
- this hack in configure.in.
-
- 7. Added support for pkg-config (2 patches were sent in).
-
- 8. Negated POSIX character classes that used a combination of internal tables
- were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
- [[:^ascii]]. Typically, they would match almost any characters. The other
- POSIX classes were not broken in this way.
-
- 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
- to find the match, as PCRE was deluded into thinking that the match had to
- start at the start point or following a newline. The same bug applied to
- patterns with negative forward assertions or any backward assertions
- preceding ".*" at the start, unless the pattern required a fixed first
- character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
-
-10. In UTF-8 mode, when moving forwards in the subject after a failed match
- starting at the last subject character, bytes beyond the end of the subject
- string were read.
-
-11. Renamed the variable "class" as "classbits" to make life easier for C++
- users. (Previously there was a macro definition, but it apparently wasn't
- enough.)
-
-12. Added the new field "tables" to the extra data so that tables can be passed
- in at exec time, or the internal tables can be re-selected. This allows
- a compiled regex to be saved and re-used at a later time by a different
- program that might have everything at different addresses.
-
-13. Modified the pcre-config script so that, when run on Solaris, it shows a
- -R library as well as a -L library.
-
-14. The debugging options of pcretest (-d on the command line or D on a
- pattern) showed incorrect output for anything following an extended class
- that contained multibyte characters and which was followed by a quantifier.
-
-15. Added optional support for general category Unicode character properties
- via the \p, \P, and \X escapes. Unicode property support implies UTF-8
- support. It adds about 90K to the size of the library. The meanings of the
- inbuilt class escapes such as \d and \s have NOT been changed.
-
-16. Updated pcredemo.c to include calls to free() to release the memory for the
- compiled pattern.
-
-17. The generated file chartables.c was being created in the source directory
- instead of in the building directory. This caused the build to fail if the
- source directory was different from the building directory, and was
- read-only.
-
-18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
- file. No doubt somebody will tell me if they don't make sense... Also added
- Dan Mooney's comments about building on OpenVMS.
-
-19. Added support for partial matching via the PCRE_PARTIAL option for
- pcre_exec() and the \P data escape in pcretest.
-
-20. Extended pcretest with 3 new pattern features:
-
- (i) A pattern option of the form ">rest-of-line" causes pcretest to
- write the compiled pattern to the file whose name is "rest-of-line".
- This is a straight binary dump of the data, with the saved pointer to
- the character tables forced to be NULL. The study data, if any, is
- written too. After writing, pcretest reads a new pattern.
-
- (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
- compiled pattern from the given file. There must not be any
- occurrences of "<" in the file name (pretty unlikely); if there are,
- pcretest will instead treat the initial "<" as a pattern delimiter.
- After reading in the pattern, pcretest goes on to read data lines as
- usual.
-
- (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
- and 16-bit fields in a compiled pattern, to simulate a pattern that
- was compiled on a host of opposite endianness.
-
-21. The pcre-exec() function can now cope with patterns that were compiled on
- hosts of opposite endianness, with this restriction:
-
- As for any compiled expression that is saved and used later, the tables
- pointer field cannot be preserved; the extra_data field in the arguments
- to pcre_exec() should be used to pass in a tables address if a value
- other than the default internal tables were used at compile time.
-
-22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
- now diagnosed as an error. Previously, most of the time, a negative number
- would have been treated as zero, but if in addition "ovector" was passed as
- NULL, a crash could occur.
-
-23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
- new versions from the libtool 1.5 distribution (the last one is a copy of
- a file called libtool.m4). This seems to have fixed the need to patch
- "configure" to support Darwin 1.3 (which I used to do). However, I still
- had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
- workstation).
-
-24. Changed the PCRE licence to be the more standard "BSD" licence.
-
-
-Version 4.5 01-Dec-03
----------------------
-
- 1. There has been some re-arrangement of the code for the match() function so
- that it can be compiled in a version that does not call itself recursively.
- Instead, it keeps those local variables that need separate instances for
- each "recursion" in a frame on the heap, and gets/frees frames whenever it
- needs to "recurse". Keeping track of where control must go is done by means
- of setjmp/longjmp. The whole thing is implemented by a set of macros that
- hide most of the details from the main code, and operates only if
- NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
- "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
- operating.
-
- To make it easier for callers to provide specially tailored get/free
- functions for this usage, two new functions, pcre_stack_malloc, and
- pcre_stack_free, are used. They are always called in strict stacking order,
- and the size of block requested is always the same.
-
- The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
- PCRE has been compiled to use the stack or the heap for recursion. The
- -C option of pcretest uses this to show which version is compiled.
-
- A new data escape \S, is added to pcretest; it causes the amounts of store
- obtained and freed by both kinds of malloc/free at match time to be added
- to the output.
-
- 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
- what's available on my current Linux desktop machine.
-
- 3. When matching a UTF-8 string, the test for a valid string at the start has
- been extended. If start_offset is not zero, PCRE now checks that it points
- to a byte that is the start of a UTF-8 character. If not, it returns
- PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
- this is necessary because there may be backward assertions in the pattern.
- When matching the same subject several times, it may save resources to use
- PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
-
- 4. The code for checking the validity of UTF-8 strings has been tightened so
- that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
- containing "overlong sequences".
-
- 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
- I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
- should have been "&", but it just so happened that all the cases this let
- through by mistake were picked up later in the function.
-
- 6. I had used a variable called "isblank" - this is a C99 function, causing
- some compilers to warn. To avoid this, I renamed it (as "blankclass").
-
- 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
- prompting; (b) run "./pcretest /dev/null" at the start of the test script
- so the version is shown; (c) stop "make test" echoing "./RunTest".
-
- 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
-
- 9. The prototype for memmove() for systems that don't have it was using
- size_t, but the inclusion of the header that defines size_t was later. I've
- moved the #includes for the C headers earlier to avoid this.
-
-10. Added some adjustments to the code to make it easier to compiler on certain
- special systems:
-
- (a) Some "const" qualifiers were missing.
- (b) Added the macro EXPORT before all exported functions; by default this
- is defined to be empty.
- (c) Changed the dftables auxiliary program (that builds chartables.c) so
- that it reads its output file name as an argument instead of writing
- to the standard output and assuming this can be redirected.
-
-11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
- class containing characters with values greater than 255, PCRE compilation
- went into a loop.
-
-12. A recursive reference to a subpattern that was within another subpattern
- that had a minimum quantifier of zero caused PCRE to crash. For example,
- (x(y(?2))z)? provoked this bug with a subject that got as far as the
- recursion. If the recursively-called subpattern itself had a zero repeat,
- that was OK.
-
-13. In pcretest, the buffer for reading a data line was set at 30K, but the
- buffer into which it was copied (for escape processing) was still set at
- 1024, so long lines caused crashes.
-
-14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
- "internal error: code overflow...". This applied to any character class
- that was followed by a possessive quantifier.
-
-15. Modified the Makefile to add libpcre.la as a prerequisite for
- libpcreposix.la because I was told this is needed for a parallel build to
- work.
-
-16. If a pattern that contained .* following optional items at the start was
- studied, the wrong optimizing data was generated, leading to matching
- errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
- matching string must start with a or b or c. The correct conclusion for
- this pattern is that a match can start with any character.
-
-
-Version 4.4 13-Aug-03
----------------------
-
- 1. In UTF-8 mode, a character class containing characters with values between
- 127 and 255 was not handled correctly if the compiled pattern was studied.
- In fixing this, I have also improved the studying algorithm for such
- classes (slightly).
-
- 2. Three internal functions had redundant arguments passed to them. Removal
- might give a very teeny performance improvement.
-
- 3. Documentation bug: the value of the capture_top field in a callout is *one
- more than* the number of the hightest numbered captured substring.
-
- 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
- in incorrectly linking with a previously installed version. They now link
- explicitly with libpcre.la.
-
- 5. configure.in no longer needs to recognize Cygwin specially.
-
- 6. A problem in pcre.in for Windows platforms is fixed.
-
- 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
- pcretest, it used to include the size of the study block as part of its
- output. Unfortunately, the structure contains a field that has a different
- size on different hardware architectures. This meant that the tests that
- showed this size failed. As the block is currently always of a fixed size,
- this information isn't actually particularly useful in pcretest output, so
- I have just removed it.
-
- 8. Three pre-processor statements accidentally did not start in column 1.
- Sadly, there are *still* compilers around that complain, even though
- standard C has not required this for well over a decade. Sigh.
-
- 9. In pcretest, the code for checking callouts passed small integers in the
- callout_data field, which is a void * field. However, some picky compilers
- complained about the casts involved for this on 64-bit systems. Now
- pcretest passes the address of the small integer instead, which should get
- rid of the warnings.
-
-10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
- both compile and run time, and gives an error if an invalid UTF-8 sequence
- is found. There is a option for disabling this check in cases where the
- string is known to be correct and/or the maximum performance is wanted.
-
-11. In response to a bug report, I changed one line in Makefile.in from
-
- -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
- to
- -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
-
- to look similar to other lines, but I have no way of telling whether this
- is the right thing to do, as I do not use Windows. No doubt I'll get told
- if it's wrong...
-
-
-Version 4.3 21-May-03
----------------------
-
-1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
- Makefile.
-
-2. Some refactoring to improve the quality of the code:
-
- (i) The utf8_table... variables are now declared "const".
-
- (ii) The code for \cx, which used the "case flipping" table to upper case
- lower case letters, now just substracts 32. This is ASCII-specific,
- but the whole concept of \cx is ASCII-specific, so it seems
- reasonable.
-
- (iii) PCRE was using its character types table to recognize decimal and
- hexadecimal digits in the pattern. This is silly, because it handles
- only 0-9, a-f, and A-F, but the character types table is locale-
- specific, which means strange things might happen. A private
- table is now used for this - though it costs 256 bytes, a table is
- much faster than multiple explicit tests. Of course, the standard
- character types table is still used for matching digits in subject
- strings against \d.
-
- (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
- ending in _t are). So I've renamed it as ESC_tee.
-
-3. The first argument for regexec() in the POSIX wrapper should have been
- defined as "const".
-
-4. Changed pcretest to use malloc() for its buffers so that they can be
- Electric Fenced for debugging.
-
-5. There were several places in the code where, in UTF-8 mode, PCRE would try
- to read one or more bytes before the start of the subject string. Often this
- had no effect on PCRE's behaviour, but in some circumstances it could
- provoke a segmentation fault.
-
-6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
- to try to read one or more bytes before the start of the subject string.
-
-7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
- UTF-8 support could misbehave in various ways if the subject string
- contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
- area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
- back over UTF-8 characters.)
-
-
-Version 4.2 14-Apr-03
----------------------
-
-1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
-
-2. Changes to the building process, supplied by Ronald Landheer-Cieslak
- [ON_WINDOWS]: new variable, "#" on non-Windows platforms
- [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
- [WIN_PREFIX]: new variable, "cyg" for Cygwin
- * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
- and BUILD_EXEEXT
- Note: automatic setting of the BUILD variables is not yet working
- set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
- compile-time but not at link-time
- [LINK]: use for linking executables only
- make different versions for Windows and non-Windows
- [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
- libraries
- [LINK_FOR_BUILD]: new variable
- [OBJEXT]: use throughout
- [EXEEXT]: use throughout
- <winshared>: new target
- <wininstall>: new target
- <dftables.o>: use native compiler
- <dftables>: use native linker
- <install>: handle Windows platform correctly
- <clean>: ditto
- <check>: ditto
- copy DLL to top builddir before testing
-
- As part of these changes, -no-undefined was removed again. This was reported
- to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
- in any case.
-
-3. Some tidies to get rid of compiler warnings:
-
- . In the match_data structure, match_limit was an unsigned long int, whereas
- match_call_count was an int. I've made them both unsigned long ints.
-
- . In pcretest the fact that a const uschar * doesn't automatically cast to
- a void * provoked a warning.
-
- . Turning on some more compiler warnings threw up some "shadow" variables
- and a few more missing casts.
-
-4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
- option, a class that contained a single character with a value between 128
- and 255 (e.g. /[\xFF]/) caused PCRE to crash.
-
-5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
- option, a class that contained several characters, but with at least one
- whose value was between 128 and 255 caused PCRE to crash.
-
-
-Version 4.1 12-Mar-03
----------------------
-
-1. Compiling with gcc -pedantic found a couple of places where casts were
-needed, and a string in dftables.c that was longer than standard compilers are
-required to support.
-
-2. Compiling with Sun's compiler found a few more places where the code could
-be tidied up in order to avoid warnings.
-
-3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
-first of these names is deprecated in the latest Autoconf in favour of the name
-CC_FOR_BUILD, because "host" is typically used to mean the system on which the
-compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
-analogy I have changed it to CFLAGS_FOR_BUILD.
-
-4. Added -no-undefined to the linking command in the Makefile, because this is
-apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
-linking step for the pcreposix library.
-
-5. PCRE was failing to diagnose the case of two named groups with the same
-name.
-
-6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
-literal character that is needed in the subject for a match, and scans along to
-ensure that it is present before embarking on the full matching process. This
-saves time in cases of nested unlimited repeats that are never going to match.
-Problem: the scan can take a lot of time if the subject is very long (e.g.
-megabytes), thus penalizing straightforward matches. It is now done only if the
-amount of subject to be scanned is less than 1000 bytes.
-
-7. A lesser problem with the same optimization is that it was recording the
-first character of an anchored pattern as "needed", thus provoking a search
-right along the subject, even when the first match of the pattern was going to
-fail. The "needed" character is now not set for anchored patterns, unless it
-follows something in the pattern that is of non-fixed length. Thus, it still
-fulfils its original purpose of finding quick non-matches in cases of nested
-unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
-
-
-Version 4.0 17-Feb-03
----------------------
-
-1. If a comment in an extended regex that started immediately after a meta-item
-extended to the end of string, PCRE compiled incorrect data. This could lead to
-all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
-
-2. Moved to autoconf 2.53 and libtool 1.4.2.
-
-3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
-the special perltest8 script is no longer needed - all the tests can be run
-from a single perltest script.
-
-4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
-by \s. It has now been removed in PCRE. This means it isn't recognized as
-whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
-class [:space:] *does* include VT, thereby creating a mess.
-
-5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
-space and tab.
-
-6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
-its new features into the main test script, reducing the number of scripts.
-
-7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
-were backward compatible, and made the (?i) apply to the whole pattern, as if
-/i were given. Now it behaves more logically, and applies the option setting
-only to what follows. PCRE has been changed to follow suit. However, if it
-finds options settings right at the start of the pattern, it extracts them into
-the global options, as before. Thus, they show up in the info data.
-
-8. Added support for the \Q...\E escape sequence. Characters in between are
-treated as literals. This is slightly different from Perl in that $ and @ are
-also handled as literals inside the quotes. In Perl, they will cause variable
-interpolation. Note the following examples:
-
- Pattern PCRE matches Perl matches
-
- \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
- \Qabc\$xyz\E abc\$xyz abc\$xyz
- \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
-
-For compatibility with Perl, \Q...\E sequences are recognized inside character
-classes as well as outside them.
-
-9. Re-organized 3 code statements in pcretest to avoid "overflow in
-floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
-(size_t) cast to one statement in pcretest and one in pcreposix to avoid
-signed/unsigned warnings.
-
-10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
-option for pcretest, so I've replaced it by a simple function that does just
-that job.
-
-11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
-"pcregrep -".
-
-12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
-Java package. This provides some syntactic sugar for simple cases of what my
-documentation calls "once-only subpatterns". A pattern such as x*+ is the same
-as (?>x*). In other words, if what is inside (?>...) is just a single repeated
-item, you can use this simplified notation. Note that only makes sense with
-greedy quantifiers. Consequently, the use of the possessive quantifier forces
-greediness, whatever the setting of the PCRE_UNGREEDY option.
-
-13. A change of greediness default within a pattern was not taking effect at
-the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
-subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
-was abstracted outside.
-
-14. PCRE now supports the \G assertion. It is true when the current matching
-position is at the start point of the match. This differs from \A when the
-starting offset is non-zero. Used with the /g option of pcretest (or similar
-code), it works in the same way as it does for Perl's /g option. If all
-alternatives of a regex begin with \G, the expression is anchored to the start
-match position, and the "anchored" flag is set in the compiled expression.
-
-15. Some bugs concerning the handling of certain option changes within patterns
-have been fixed. These applied to options other than (?ims). For example,
-"a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
-been the other way round. Some of this was related to change 7 above.
-
-16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
-features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
-and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
-POSIX classes only within a class (e.g. /[[:alpha:]]/).
-
-17. Added support for Perl's \C escape. This matches one byte, even in UTF8
-mode. Unlike ".", it always matches newline, whatever the setting of
-PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
-assertions. Perl allows it, but it doesn't (in general) work because it can't
-calculate the length of the lookbehind. At least, that's the case for Perl
-5.8.0 - I've been told they are going to document that it doesn't work in
-future.
-
-18. Added an error diagnosis for escapes that PCRE does not support: these are
-\L, \l, \N, \P, \p, \U, \u, and \X.
-
-19. Although correctly diagnosing a missing ']' in a character class, PCRE was
-reading past the end of the pattern in cases such as /[abcd/.
-
-20. PCRE was getting more memory than necessary for patterns with classes that
-contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
-
-21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
-compiling PCRE for use with Virtual Pascal.
-
-22. Small fix to the Makefile to make it work properly if the build is done
-outside the source tree.
-
-23. Added a new extension: a condition to go with recursion. If a conditional
-subpattern starts with (?(R) the "true" branch is used if recursion has
-happened, whereas the "false" branch is used only at the top level.
-
-24. When there was a very long string of literal characters (over 255 bytes
-without UTF support, over 250 bytes with UTF support), the computation of how
-much memory was required could be incorrect, leading to segfaults or other
-strange effects.
-
-25. PCRE was incorrectly assuming anchoring (either to start of subject or to
-start of line for a non-DOTALL pattern) when a pattern started with (.*) and
-there was a subsequent back reference to those brackets. This meant that, for
-example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
-possible to check for precisely this case. All we can do is abandon the
-optimization if .* occurs inside capturing brackets when there are any back
-references whatsoever. (See below for a better fix that came later.)
-
-26. The handling of the optimization for finding the first character of a
-non-anchored pattern, and for finding a character that is required later in the
-match were failing in some cases. This didn't break the matching; it just
-failed to optimize when it could. The way this is done has been re-implemented.
-
-27. Fixed typo in error message for invalid (?R item (it said "(?p").
-
-28. Added a new feature that provides some of the functionality that Perl
-provides with (?{...}). The facility is termed a "callout". The way it is done
-in PCRE is for the caller to provide an optional function, by setting
-pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
-global variable. By default it is unset, which disables all calling out. To get
-the function called, the regex must include (?C) at appropriate points. This
-is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
-This provides a means of identifying different callout points. When PCRE
-reaches such a point in the regex, if pcre_callout has been set, the external
-function is called. It is provided with data in a structure called
-pcre_callout_block, which is defined in pcre.h. If the function returns 0,
-matching continues; if it returns a non-zero value, the match at the current
-point fails. However, backtracking will occur if possible. [This was changed
-later and other features added - see item 49 below.]
-
-29. pcretest is upgraded to test the callout functionality. It provides a
-callout function that displays information. By default, it shows the start of
-the match and the current position in the text. There are some new data escapes
-to vary what happens:
-
- \C+ in addition, show current contents of captured substrings
- \C- do not supply a callout function
- \C!n return 1 when callout number n is reached
- \C!n!m return 1 when callout number n is reached for the mth time
-
-30. If pcregrep was called with the -l option and just a single file name, it
-output "<stdin>" if a match was found, instead of the file name.
-
-31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
-slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
-pcre_exec(). This saves a malloc/free per call. The default value of
-POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
-when configuring.
-
-32. The default maximum size of a compiled pattern is 64K. There have been a
-few cases of people hitting this limit. The code now uses macros to handle the
-storing of links as offsets within the compiled pattern. It defaults to 2-byte
-links, but this can be changed to 3 or 4 bytes by --with-link-size when
-configuring. Tests 2 and 5 work only with 2-byte links because they output
-debugging information about compiled patterns.
-
-33. Internal code re-arrangements:
-
-(a) Moved the debugging function for printing out a compiled regex into
- its own source file (printint.c) and used #include to pull it into
- pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
- separate copies.
-
-(b) Defined the list of op-code names for debugging as a macro in
- internal.h so that it is next to the definition of the opcodes.
-
-(c) Defined a table of op-code lengths for simpler skipping along compiled
- code. This is again a macro in internal.h so that it is next to the
- definition of the opcodes.
-
-34. Added support for recursive calls to individual subpatterns, along the
-lines of Robin Houston's patch (but implemented somewhat differently).
-
-35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
-allow it to read and process whole directories in Win32. This code was
-contributed by Lionel Fourquaux; it has not been tested by me.
-
-36. Added support for named subpatterns. The Python syntax (?P<name>...) is
-used to name a group. Names consist of alphanumerics and underscores, and must
-be unique. Back references use the syntax (?P=name) and recursive calls use
-(?P>name) which is a PCRE extension to the Python extension. Groups still have
-numbers. The function pcre_fullinfo() can be used after compilation to extract
-a name/number map. There are three relevant calls:
-
- PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
- PCRE_INFO_NAMECOUNT yields the number of entries
- PCRE_INFO_NAMETABLE yields a pointer to the map.
-
-The map is a vector of fixed-size entries. The size of each entry depends on
-the length of the longest name used. The first two bytes of each entry are the
-group number, most significant byte first. There follows the corresponding
-name, zero terminated. The names are in alphabetical order.
-
-37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
-case instead of 255. Making it the same both with and without UTF-8 support
-means that the same test output works with both.
-
-38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
-calling malloc() with a zero argument.
-
-39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
-optimization. I've improved things by keeping a bitmap of backreferences with
-numbers 1-31 so that if .* occurs inside capturing brackets that are not in
-fact referenced, the optimization can be applied. It is unlikely that a
-relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
-the match to follow \n) will appear inside brackets with a number greater than
-31, but if it does, any back reference > 31 suppresses the optimization.
-
-40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
-of disabling numbered capturing parentheses. Any opening parenthesis that is
-not followed by ? behaves as if it were followed by ?: but named parentheses
-can still be used for capturing (and they will acquire numbers in the usual
-way).
-
-41. Redesigned the return codes from the match() function into yes/no/error so
-that errors can be passed back from deep inside the nested calls. A malloc
-failure while inside a recursive subpattern call now causes the
-PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
-
-42. It is now possible to set a limit on the number of times the match()
-function is called in a call to pcre_exec(). This facility makes it possible to
-limit the amount of recursion and backtracking, though not in a directly
-obvious way, because the match() function is used in a number of different
-circumstances. The count starts from zero for each position in the subject
-string (for non-anchored patterns). The default limit is, for compatibility, a
-large number, namely 10 000 000. You can change this in two ways:
-
-(a) When configuring PCRE before making, you can use --with-match-limit=n
- to set a default value for the compiled library.
-
-(b) For each call to pcre_exec(), you can pass a pcre_extra block in which
- a different value is set. See 45 below.
-
-If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
-
-43. Added a new function pcre_config(int, void *) to enable run-time extraction
-of things that can be changed at compile time. The first argument specifies
-what is wanted and the second points to where the information is to be placed.
-The current list of available information is:
-
- PCRE_CONFIG_UTF8
-
-The output is an integer that is set to one if UTF-8 support is available;
-otherwise it is set to zero.
-
- PCRE_CONFIG_NEWLINE
-
-The output is an integer that it set to the value of the code that is used for
-newline. It is either LF (10) or CR (13).
-
- PCRE_CONFIG_LINK_SIZE
-
-The output is an integer that contains the number of bytes used for internal
-linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
-
- PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
-
-The output is an integer that contains the threshold above which the POSIX
-interface uses malloc() for output vectors. See item 31 above.
-
- PCRE_CONFIG_MATCH_LIMIT
-
-The output is an unsigned integer that contains the default limit of the number
-of match() calls in a pcre_exec() execution. See 42 above.
-
-44. pcretest has been upgraded by the addition of the -C option. This causes it
-to extract all the available output from the new pcre_config() function, and to
-output it. The program then exits immediately.
-
-45. A need has arisen to pass over additional data with calls to pcre_exec() in
-order to support additional features. One way would have been to define
-pcre_exec2() (for example) with extra arguments, but this would not have been
-extensible, and would also have required all calls to the original function to
-be mapped to the new one. Instead, I have chosen to extend the mechanism that
-is used for passing in "extra" data from pcre_study().
-
-The pcre_extra structure is now exposed and defined in pcre.h. It currently
-contains the following fields:
-
- flags a bitmap indicating which of the following fields are set
- study_data opaque data from pcre_study()
- match_limit a way of specifying a limit on match() calls for a specific
- call to pcre_exec()
- callout_data data for callouts (see 49 below)
-
-The flag bits are also defined in pcre.h, and are
-
- PCRE_EXTRA_STUDY_DATA
- PCRE_EXTRA_MATCH_LIMIT
- PCRE_EXTRA_CALLOUT_DATA
-
-The pcre_study() function now returns one of these new pcre_extra blocks, with
-the actual study data pointed to by the study_data field, and the
-PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
-before. That is, this change is entirely upwards-compatible and requires no
-change to existing code.
-
-If you want to pass in additional data to pcre_exec(), you can either place it
-in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
-block.
-
-46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
-data string contains the escape sequence \M, pcretest calls pcre_exec() several
-times with different match limits, until it finds the minimum value needed for
-pcre_exec() to complete. The value is then output. This can be instructive; for
-most simple matches the number is quite small, but for pathological cases it
-gets very large very quickly.
-
-47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
-returns the size of the data block pointed to by the study_data field in a
-pcre_extra block, that is, the value that was passed as the argument to
-pcre_malloc() when PCRE was getting memory in which to place the information
-created by pcre_study(). The fourth argument should point to a size_t variable.
-pcretest has been extended so that this information is shown after a successful
-pcre_study() call when information about the compiled regex is being displayed.
-
-48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
-because what follows is always an absolute path. (Later: it turns out that this
-is more than cosmetic for MinGW, because it doesn't like empty path
-components.)
-
-49. Some changes have been made to the callout feature (see 28 above):
-
-(i) A callout function now has three choices for what it returns:
-
- 0 => success, carry on matching
- > 0 => failure at this point, but backtrack if possible
- < 0 => serious error, return this value from pcre_exec()
-
- Negative values should normally be chosen from the set of PCRE_ERROR_xxx
- values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
- "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
- use by callout functions. It will never be used by PCRE itself.
-
-(ii) The pcre_extra structure (see 45 above) has a void * field called
- callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
- pcre_callout_block structure has a field of the same name. The contents of
- the field passed in the pcre_extra structure are passed to the callout
- function in the corresponding field in the callout block. This makes it
- easier to use the same callout-containing regex from multiple threads. For
- testing, the pcretest program has a new data escape
-
- \C*n pass the number n (may be negative) as callout_data
-
- If the callout function in pcretest receives a non-zero value as
- callout_data, it returns that value.
-
-50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
-there were some redundant $(CFLAGS) in commands that are now specified as
-$(LINK), which already includes $(CFLAGS).
-
-51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
-has been compiled with UTF-8 support *and* pcre_compile() has been compiled
-with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
-one-byte characters throughout. Note that case-insensitive matching applies
-only to characters whose values are less than 256. PCRE doesn't support the
-notion of cases for higher-valued characters.
-
-(i) A character class whose characters are all within 0-255 is handled as
- a bit map, and the map is inverted for negative classes. Previously, a
- character > 255 always failed to match such a class; however it should
- match if the class was a negative one (e.g. [^ab]). This has been fixed.
-
-(ii) A negated character class with a single character < 255 is coded as
- "not this character" (OP_NOT). This wasn't working properly when the test
- character was multibyte, either singly or repeated.
-
-(iii) Repeats of multibyte characters are now handled correctly in UTF-8
- mode, for example: \x{100}{2,3}.
-
-(iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
- singly or repeated) now correctly test multibyte characters. However,
- PCRE doesn't recognize any characters with values greater than 255 as
- digits, spaces, or word characters. Such characters always match \D, \S,
- and \W, and never match \d, \s, or \w.
-
-(v) Classes may now contain characters and character ranges with values
- greater than 255. For example: [ab\x{100}-\x{400}].
-
-(vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
- PCRE in UTF-8 mode.
-
-52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
-PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
-retained for backwards compatibility. (Note that LASTLITERAL is also a byte
-value.)
-
-53. The single man page has become too large. I have therefore split it up into
-a number of separate man pages. These also give rise to individual HTML pages;
-these are now put in a separate directory, and there is an index.html page that
-lists them all. Some hyperlinking between the pages has been installed.
-
-54. Added convenience functions for handling named capturing parentheses.
-
-55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
-aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
-true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
-are faulted.
-
-56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
-calling configure. These values are used when compiling the dftables.c program
-which is run to generate the source of the default character tables. They
-default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
-you will need to set these values.
-
-57. Updated the building process for Windows DLL, as provided by Fred Cox.
-
-
-Version 3.9 02-Jan-02
----------------------
-
-1. A bit of extraneous text had somehow crept into the pcregrep documentation.
-
-2. If --disable-static was given, the building process failed when trying to
-build pcretest and pcregrep. (For some reason it was using libtool to compile
-them, which is not right, as they aren't part of the library.)
-
-
-Version 3.8 18-Dec-01
----------------------
-
-1. The experimental UTF-8 code was completely screwed up. It was packing the
-bytes in the wrong order. How dumb can you get?
-
-
-Version 3.7 29-Oct-01
----------------------
-
-1. In updating pcretest to check change 1 of version 3.6, I screwed up.
-This caused pcretest, when used on the test data, to segfault. Unfortunately,
-this didn't happen under Solaris 8, where I normally test things.
-
-2. The Makefile had to be changed to make it work on BSD systems, where 'make'
-doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
-isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
-this fix an hour or so after the initial 3.7 release.)
-
-
-Version 3.6 23-Oct-01
----------------------
-
-1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
-offsets passed as NULL with zero offset count.
-
-2. The config.guess and config.sub files had not been updated when I moved to
-the latest autoconf.
-
-
-Version 3.5 15-Aug-01
----------------------
-
-1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
-had been forgotten.
-
-2. By using declared but undefined structures, we can avoid using "void"
-definitions in pcre.h while keeping the internal definitions of the structures
-private.
-
-3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
-user point of view, this means that both static and shared libraries are built
-by default, but this can be individually controlled. More of the work of
-handling this static/shared cases is now inside libtool instead of PCRE's make
-file.
-
-4. The pcretest utility is now installed along with pcregrep because it is
-useful for users (to test regexs) and by doing this, it automatically gets
-relinked by libtool. The documentation has been turned into a man page, so
-there are now .1, .txt, and .html versions in /doc.
-
-5. Upgrades to pcregrep:
- (i) Added long-form option names like gnu grep.
- (ii) Added --help to list all options with an explanatory phrase.
- (iii) Added -r, --recursive to recurse into sub-directories.
- (iv) Added -f, --file to read patterns from a file.
-
-6. pcre_exec() was referring to its "code" argument before testing that
-argument for NULL (and giving an error if it was NULL).
-
-7. Upgraded Makefile.in to allow for compiling in a different directory from
-the source directory.
-
-8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
-options bits, the pointer it was passed was to an int instead of to an unsigned
-long int. This mattered only on 64-bit systems.
-
-9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
-generated) instead of pcre.in, which it its source. Also made the same change
-in several of the .c files.
-
-10. A new release of gcc defines printf() as a macro, which broke pcretest
-because it had an ifdef in the middle of a string argument for printf(). Fixed
-by using separate calls to printf().
-
-11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
-script, to force use of CR or LF instead of \n in the source. On non-Unix
-systems, the value can be set in config.h.
-
-12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
-absolute limit. Changed the text of the error message to make this clear, and
-likewise updated the man page.
-
-13. The limit of 99 on the number of capturing subpatterns has been removed.
-The new limit is 65535, which I hope will not be a "real" limit.
-
-
-Version 3.4 22-Aug-00
----------------------
-
-1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
-
-2. Diagnose condition (?(0) as an error instead of crashing on matching.
-
-
-Version 3.3 01-Aug-00
----------------------
-
-1. If an octal character was given, but the value was greater than \377, it
-was not getting masked to the least significant bits, as documented. This could
-lead to crashes in some systems.
-
-2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
-the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
-
-3. Added the functions pcre_free_substring() and pcre_free_substring_list().
-These just pass their arguments on to (pcre_free)(), but they are provided
-because some uses of PCRE bind it to non-C systems that can call its functions,
-but cannot call free() or pcre_free() directly.
-
-4. Add "make test" as a synonym for "make check". Corrected some comments in
-the Makefile.
-
-5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
-Makefile.
-
-6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
-command called pgrep for grepping around the active processes.
-
-7. Added the beginnings of support for UTF-8 character strings.
-
-8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
-RANLIB to ./ltconfig so that they are used by libtool. I think these are all
-the relevant ones. (AR is not passed because ./ltconfig does its own figuring
-out for the ar command.)
-
-
-Version 3.2 12-May-00
----------------------
-
-This is purely a bug fixing release.
-
-1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
-of ZA. This was just one example of several cases that could provoke this bug,
-which was introduced by change 9 of version 2.00. The code for breaking
-infinite loops after an iteration that matches an empty string was't working
-correctly.
-
-2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
-when matched against abbab (for example). After matching an empty string, it
-wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
-caused it to match further down the string than it should.
-
-3. The code contained an inclusion of sys/types.h. It isn't clear why this
-was there because it doesn't seem to be needed, and it causes trouble on some
-systems, as it is not a Standard C header. It has been removed.
-
-4. Made 4 silly changes to the source to avoid stupid compiler warnings that
-were reported on the Macintosh. The changes were from
-
- while ((c = *(++ptr)) != 0 && c != '\n');
-to
- while ((c = *(++ptr)) != 0 && c != '\n') ;
-
-Totally extraordinary, but if that's what it takes...
-
-5. PCRE is being used in one environment where neither memmove() nor bcopy() is
-available. Added HAVE_BCOPY and an autoconf test for it; if neither
-HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
-assumes the way PCRE uses memmove() (always moving upwards).
-
-6. PCRE is being used in one environment where strchr() is not available. There
-was only one use in pcre.c, and writing it out to avoid strchr() probably gives
-faster code anyway.
-
-
-Version 3.1 09-Feb-00
----------------------
-
-The only change in this release is the fixing of some bugs in Makefile.in for
-the "install" target:
-
-(1) It was failing to install pcreposix.h.
-
-(2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
-
-
-Version 3.0 01-Feb-00
----------------------
-
-1. Add support for the /+ modifier to perltest (to output $` like it does in
-pcretest).
-
-2. Add support for the /g modifier to perltest.
-
-3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
-matches null strings.
-
-4. Fix perltest so that it doesn't do unwanted things when fed an empty
-pattern. Perl treats empty patterns specially - it reuses the most recent
-pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
-effect.
-
-5. The POSIX interface was broken in that it was just handing over the POSIX
-captured string vector to pcre_exec(), but (since release 2.00) PCRE has
-required a bigger vector, with some working space on the end. This means that
-the POSIX wrapper now has to get and free some memory, and copy the results.
-
-6. Added some simple autoconf support, placing the test data and the
-documentation in separate directories, re-organizing some of the
-information files, and making it build pcre-config (a GNU standard). Also added
-libtool support for building PCRE as a shared library, which is now the
-default.
-
-7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
-09 are not valid octal constants. Single digits will be used for minor values
-less than 10.
-
-8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
-existing programs that set these in the POSIX interface can use PCRE without
-modification.
-
-9. Added a new function, pcre_fullinfo() with an extensible interface. It can
-return all that pcre_info() returns, plus additional data. The pcre_info()
-function is retained for compatibility, but is considered to be obsolete.
-
-10. Added experimental recursion feature (?R) to handle one common case that
-Perl 5.6 will be able to do with (?p{...}).
-
-11. Added support for POSIX character classes like [:alpha:], which Perl is
-adopting.
-
-
-Version 2.08 31-Aug-99
-----------------------
-
-1. When startoffset was not zero and the pattern began with ".*", PCRE was not
-trying to match at the startoffset position, but instead was moving forward to
-the next newline as if a previous match had failed.
-
-2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
-and could get into a loop if a null string was matched other than at the start
-of the subject.
-
-3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
-be distinguished at compile time, and for completeness also added PCRE_DATE.
-
-5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
-in GnuWin32 environments.
-
-
-Version 2.07 29-Jul-99
-----------------------
-
-1. The documentation is now supplied in plain text form and HTML as well as in
-the form of man page sources.
-
-2. C++ compilers don't like assigning (void *) values to other pointer types.
-In particular this affects malloc(). Although there is no problem in Standard
-C, I've put in casts to keep C++ compilers happy.
-
-3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
-should be (const char *).
-
-4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
-be useful for non-Unix systems who don't want to bother with the POSIX stuff.
-However, I haven't made this a standard facility. The documentation doesn't
-mention it, and the Makefile doesn't support it.
-
-5. The Makefile now contains an "install" target, with editable destinations at
-the top of the file. The pcretest program is not installed.
-
-6. pgrep -V now gives the PCRE version number and date.
-
-7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
-causing the entire string to be ignored, instead of just the last character.
-
-8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
-non-matching string, it can take a very, very long time, even for strings of
-quite modest length, because of the nested recursion. PCRE now does better in
-some of these cases. It does this by remembering the last required literal
-character in the pattern, and pre-searching the subject to ensure it is present
-before running the real match. In other words, it applies a heuristic to detect
-some types of certain failure quickly, and in the above example, if presented
-with a string that has no trailing " it gives "no match" very quickly.
-
-9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
-other alternatives are tried instead.
-
-
-Version 2.06 09-Jun-99
-----------------------
-
-1. Change pcretest's output for amount of store used to show just the code
-space, because the remainder (the data block) varies in size between 32-bit and
-64-bit systems.
-
-2. Added an extra argument to pcre_exec() to supply an offset in the subject to
-start matching at. This allows lookbehinds to work when searching for multiple
-occurrences in a string.
-
-3. Added additional options to pcretest for testing multiple occurrences:
-
- /+ outputs the rest of the string that follows a match
- /g loops for multiple occurrences, using the new startoffset argument
- /G loops for multiple occurrences by passing an incremented pointer
-
-4. PCRE wasn't doing the "first character" optimization for patterns starting
-with \b or \B, though it was doing it for other lookbehind assertions. That is,
-it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
-the letter 'x'. On long subject strings, this gives a significant speed-up.
-
-
-Version 2.05 21-Apr-99
-----------------------
-
-1. Changed the type of magic_number from int to long int so that it works
-properly on 16-bit systems.
-
-2. Fixed a bug which caused patterns starting with .* not to work correctly
-when the subject string contained newline characters. PCRE was assuming
-anchoring for such patterns in all cases, which is not correct because .* will
-not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
-DOTALL is set at top level; otherwise it knows that patterns starting with .*
-must be retried after every newline in the subject.
-
-
-Version 2.04 18-Feb-99
-----------------------
-
-1. For parenthesized subpatterns with repeats whose minimum was zero, the
-computation of the store needed to hold the pattern was incorrect (too large).
-If such patterns were nested a few deep, this could multiply and become a real
-problem.
-
-2. Added /M option to pcretest to show the memory requirement of a specific
-pattern. Made -m a synonym of -s (which does this globally) for compatibility.
-
-3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
-compiled in such a way that the backtracking after subsequent failure was
-pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
-((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
-
-
-Version 2.03 02-Feb-99
-----------------------
-
-1. Fixed typo and small mistake in man page.
-
-2. Added 4th condition (GPL supersedes if conflict) and created separate
-LICENCE file containing the conditions.
-
-3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
-Perl, that is the internal \ allows the delimiter to be included in the
-pattern. Locked out the use of \ as a delimiter. If \ immediately follows
-the final delimiter, add \ to the end of the pattern (to test the error).
-
-4. Added the convenience functions for extracting substrings after a successful
-match. Updated pcretest to make it able to test these functions.
-
-
-Version 2.02 14-Jan-99
-----------------------
-
-1. Initialized the working variables associated with each extraction so that
-their saving and restoring doesn't refer to uninitialized store.
-
-2. Put dummy code into study.c in order to trick the optimizer of the IBM C
-compiler for OS/2 into generating correct code. Apparently IBM isn't going to
-fix the problem.
-
-3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
-calls, and wasn't printing the correct value for compiling calls. Increased the
-default value of LOOPREPEAT, and the number of significant figures in the
-times.
-
-4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
-
-5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
-a building problem on Windows NT with a FAT file system.
-
-
-Version 2.01 21-Oct-98
-----------------------
-
-1. Changed the API for pcre_compile() to allow for the provision of a pointer
-to character tables built by pcre_maketables() in the current locale. If NULL
-is passed, the default tables are used.
-
-
-Version 2.00 24-Sep-98
-----------------------
-
-1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
-it any more.
-
-2. Allow quantification of (?>) groups, and make it work correctly.
-
-3. The first character computation wasn't working for (?>) groups.
-
-4. Correct the implementation of \Z (it is permitted to match on the \n at the
-end of the subject) and add 5.005's \z, which really does match only at the
-very end of the subject.
-
-5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
-
-6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
-DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
-localized options. All options to pcre_study() were also removed.
-
-7. Add other new features from 5.005:
-
- $(?<= positive lookbehind
- $(?<! negative lookbehind
- (?imsx-imsx) added the unsetting capability
- such a setting is global if at outer level; local otherwise
- (?imsx-imsx:) non-capturing groups with option setting
- (?(cond)re|re) conditional pattern matching
-
- A backreference to itself in a repeated group matches the previous
- captured string.
-
-8. General tidying up of studying (both automatic and via "study")
-consequential on the addition of new assertions.
-
-9. As in 5.005, unlimited repeated groups that could match an empty substring
-are no longer faulted at compile time. Instead, the loop is forcibly broken at
-runtime if any iteration does actually match an empty substring.
-
-10. Include the RunTest script in the distribution.
-
-11. Added tests from the Perl 5.005_02 distribution. This showed up a few
-discrepancies, some of which were old and were also with respect to 5.004. They
-have now been fixed.
-
-
-Version 1.09 28-Apr-98
-----------------------
-
-1. A negated single character class followed by a quantifier with a minimum
-value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
-program crashes, or just wrong answers. This did not apply to negated classes
-containing more than one character, or to minima other than one.
-
-
-Version 1.08 27-Mar-98
-----------------------
-
-1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
-
-2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
-latter must appear before anything that relies on it in the pattern.
-
-
-Version 1.07 16-Feb-98
-----------------------
-
-1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
-repeat of a potentially empty string).
-
-
-Version 1.06 23-Jan-98
-----------------------
-
-1. Added Markus Oberhumer's little patches for C++.
-
-2. Literal strings longer than 255 characters were broken.
-
-
-Version 1.05 23-Dec-97
-----------------------
-
-1. Negated character classes containing more than one character were failing if
-PCRE_CASELESS was set at run time.
-
-
-Version 1.04 19-Dec-97
-----------------------
-
-1. Corrected the man page, where some "const" qualifiers had been omitted.
-
-2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
-input syntax.
-
-3. Fixed memory leak which occurred when a regex with back references was
-matched with an offsets vector that wasn't big enough. The temporary memory
-that is used in this case wasn't being freed if the match failed.
-
-4. Tidied pcretest to ensure it frees memory that it gets.
-
-5. Temporary memory was being obtained in the case where the passed offsets
-vector was exactly big enough.
-
-6. Corrected definition of offsetof() from change 5 below.
-
-7. I had screwed up change 6 below and broken the rules for the use of
-setjmp(). Now fixed.
-
-
-Version 1.03 18-Dec-97
-----------------------
-
-1. A erroneous regex with a missing opening parenthesis was correctly
-diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
-on some systems.
-
-2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
-it was reported that one broken compiler failed on the former because "code" is
-also an independent variable.
-
-3. The erroneous regex a[]b caused an array overrun reference.
-
-4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
-fail on data ending with that character. (It was going on too far, and checking
-the next character, typically a binary zero.) This was specific to the
-optimized code for single-character negative classes.
-
-5. Added a contributed patch from the TIN world which does the following:
-
- + Add an undef for memmove, in case the the system defines a macro for it.
-
- + Add a definition of offsetof(), in case there isn't one. (I don't know
- the reason behind this - offsetof() is part of the ANSI standard - but
- it does no harm).
-
- + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
- most of the places where whitespace preceded '#'. I have given up and
- allowed the remaining 2 cases to be at the margin.
-
- + Rename some variables in pcre to eliminate shadowing. This seems very
- pedantic, but does no harm, of course.
-
-6. Moved the call to setjmp() into its own function, to get rid of warnings
-from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
-
-7. Constructs such as \d{8,} were compiling into the equivalent of
-\d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
-outcome, but in this particular case used more store than had been allocated,
-which caused the bug to be discovered because it threw up an internal error.
-
-8. The debugging code in both pcre and pcretest for outputting the compiled
-form of a regex was going wrong in the case of back references followed by
-curly-bracketed repeats.
-
-
-Version 1.02 12-Dec-97
-----------------------
-
-1. Typos in pcre.3 and comments in the source fixed.
-
-2. Applied a contributed patch to get rid of places where it used to remove
-'const' from variables, and fixed some signed/unsigned and uninitialized
-variable warnings.
-
-3. Added the "runtest" target to Makefile.
-
-4. Set default compiler flag to -O2 rather than just -O.
-
-
-Version 1.01 19-Nov-97
-----------------------
-
-1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
-like /([ab]*)*/, that is, for classes with more than one character in them.
-
-2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
-as /((?>a*))*/ (a PCRE_EXTRA facility).
-
-
-Version 1.00 18-Nov-97
-----------------------
-
-1. Added compile-time macros to support systems such as SunOS4 which don't have
-memmove() or strerror() but have other things that can be used instead.
-
-2. Arranged that "make clean" removes the executables.
-
-
-Version 0.99 27-Oct-97
-----------------------
-
-1. Fixed bug in code for optimizing classes with only one character. It was
-initializing a 32-byte map regardless, which could cause it to run off the end
-of the memory it had got.
-
-2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
-
-
-Version 0.98 22-Oct-97
-----------------------
-
-1. Fixed bug in code for handling temporary memory usage when there are more
-back references than supplied space in the ovector. This could cause segfaults.
-
-
-Version 0.97 21-Oct-97
-----------------------
-
-1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
-
-2. Optimized negated single characters not to use a bit map.
-
-3. Brought error texts together as macro definitions; clarified some of them;
-fixed one that was wrong - it said "range out of order" when it meant "invalid
-escape sequence".
-
-4. Changed some char * arguments to const char *.
-
-5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
-
-6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
-pcretest.
-
-
-Version 0.96 16-Oct-97
-----------------------
-
-1. Added a simple "pgrep" utility to the distribution.
-
-2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
-unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
-where "ddd" means "one or more decimal digits".
-
-3. Fixed serious bug. If a pattern had a back reference, but the call to
-pcre_exec() didn't supply a large enough ovector to record the related
-identifying subpattern, the match always failed. PCRE now remembers the number
-of the largest back reference, and gets some temporary memory in which to save
-the offsets during matching if necessary, in order to ensure that
-backreferences always work.
-
-4. Increased the compatibility with Perl in a number of ways:
-
- (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
- to request this handling. The option can be set at compile or exec time.
-
- (b) $ matches before a terminating newline by default; an option
- PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
- mode). The option can be set at compile or exec time.
-
- (c) The handling of \ followed by a digit other than 0 is now supposed to be
- the same as Perl's. If the decimal number it represents is less than 10
- or there aren't that many previous left capturing parentheses, an octal
- escape is read. Inside a character class, it's always an octal escape,
- even if it is a single digit.
-
- (d) An escaped but undefined alphabetic character is taken as a literal,
- unless PCRE_EXTRA is set. Currently this just reserves the remaining
- escapes.
-
- (e) {0} is now permitted. (The previous item is removed from the compiled
- pattern).
-
-5. Changed all the names of code files so that the basic parts are no longer
-than 10 characters, and abolished the teeny "globals.c" file.
-
-6. Changed the handling of character classes; they are now done with a 32-byte
-bit map always.
-
-7. Added the -d and /D options to pcretest to make it possible to look at the
-internals of compilation without having to recompile pcre.
-
-
-Version 0.95 23-Sep-97
-----------------------
-
-1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
-\x20 at the start of a run of normal characters. These were being treated as
-real characters, instead of the source characters being re-checked.
-
-
-Version 0.94 18-Sep-97
-----------------------
-
-1. The functions are now thread-safe, with the caveat that the global variables
-containing pointers to malloc() and free() or alternative functions are the
-same for all threads.
-
-2. Get pcre_study() to generate a bitmap of initial characters for non-
-anchored patterns when this is possible, and use it if passed to pcre_exec().
-
-
-Version 0.93 15-Sep-97
-----------------------
-
-1. /(b)|(:+)/ was computing an incorrect first character.
-
-2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
-but not actually doing anything yet.
-
-3. Treat "-" characters in classes that cannot be part of ranges as literals,
-as Perl does (e.g. [-az] or [az-]).
-
-4. Set the anchored flag if a branch starts with .* or .*? because that tests
-all possible positions.
-
-5. Split up into different modules to avoid including unneeded functions in a
-compiled binary. However, compile and exec are still in one module. The "study"
-function is split off.
-
-6. The character tables are now in a separate module whose source is generated
-by an auxiliary program - but can then be edited by hand if required. There are
-now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
-toupper() in the code.
-
-7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
-make them global. Abolish the function for setting them, as the caller can now
-set them directly.
-
-
-Version 0.92 11-Sep-97
-----------------------
-
-1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
-(e.g. /a{1,3}/) was broken (I mis-optimized it).
-
-2. Caseless matching was not working in character classes if the characters in
-the pattern were in upper case.
-
-3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
-
-4. Make PCRE_ANCHORED public and accept as a compile option.
-
-5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
-PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
-pass them.
-
-6. Give an error if bad option bits passed at compile or run time.
-
-7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
-pcretest to cause it to pass that flag.
-
-8. Add pcre_info(), to get the number of identifying subpatterns, the stored
-options, and the first character, if set.
-
-9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
-
-
-Version 0.91 10-Sep-97
-----------------------
-
-1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
-match the empty string as in /(a*)*/. It was looping and ultimately crashing.
-
-2. PCRE was looping on encountering an indefinitely repeated back reference to
-a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
-Perl does - treats the match as successful.
-
-****