An oversight in r320742 caused BREs to become sensitive to the branching operator prematurely, which caused
breakage in some limited situations -- namely, those that tried to use branching in a BRE. Most of these scenarios
had already been corrected beforehand to properly use gsed or grep for GNU extensions, so the damage is
slightly mitigated.
Reported by: antoine
Reported by: antoine
Approved by: emaste (mentor)
Differential Revision: https://reviews.freebsd.org/D11522
p_branch_empty was declared but never used due to an oversight. Use it as
designed, further comment on its return value.
Reported by: Jenkins (head-sparc64)
Reviewed by: emaste
Approved by: emaste (mentor)
MFC with: r320742
Differential Revision: https://reviews.freebsd.org/D11506
EREs closer together. Prepare for this and reduce the diff of libregex changes by
refactoring and combining the top-level parsers for EREs/BREs ahead of time.
Branching functionality has been split out to make it easier to follow the combined
version of the top-level parser. It may also be enabled in the parsing context to make
it easier when libregex enables branching for BREs.
A branching context was also added for the various branching functions and so that
BREs, for instance, can determine if they're the first expression in a chain of expressions
within the current branch and treat '*' as ordinary if so.
This should have no functional impact and negligible performance impact.
Reviewed by: cem, emaste, pfg
Approved by: emaste (mentor)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D10920
When passed the invalid regular expression "a**", the error is
eventually detected and seterr() is called. It sets p->error
appropriatly and p->next and p->end to nuls which is a never used char
nuls[10] which is zeros due to .bss initialization. Unfortunatly,
p_ere_exp() and p_simp_re() both have fall through cases where they set
the error, decrement p->next and access it which means a read from what
ever .bss variable comes before nuls.
Found with regex_test:repet_multi and CHERI bounds checking.
Reviewed by: ngie, pfg, emaste
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D10541
Taking some hints from the regex variant in nvi(1) and higher-level
compiler warnings, update some types in our regex(3) implementation.
Joint work with: Kyle Evans
MFC after: 2 weeks
reallocarray(3) is a non portable extension that originated in OpenBSD.
Given that it is already in FreeBSD's libc it is useful for the cases
where reallocation involves a multiplication.
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D9955
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
locale (which cause core dump) by removing whole 'table' argument
by which it passed.
2) Restore __collate_range_cmp() in __sccl().
3) Collating [a-z] range in regcomp() only for single bytes locales
(we can't do it now for other ones). In previous state only first 256
wchars are considered and all others are just silently dropped from the
range.
Instead of changing whole course to another POSIX-permitted way
for consistency and uniformity I decide to completely ignore missing
regex fucntionality and concentrace on fixing bugs in what we have now,
too many small obstacles instead, counting ports.
Only first 256 wide chars are considered currently, all other are just
dropped from the range. Proper implementation require reverse tables
database lookup, since objects are really big as max UTF-8 (1114112
code points), so just the same scanning as it was for 256 chars will
slow things down.
POSIX does not require collation for [a-z] type ranges and does not
prohibit it for non-POSIX locales. POSIX require collation for ranges
only for POSIX (or C) locale which is equal to ASCII and binary for
other chars, so we already have it.
No other *BSD implements collation for [a-z] type ranges.
Restore ABI compatibility with unused now __collate_range_cmp() which
is visible from outside (will be removed later).
When collation support was brought in, the second and third
arguments in __collate_range_cmp() were changed from int to
wchar_t, breaking the ABI. Change them to a "char" type which
makes more sense and keeps the ABI compatible.
Also introduce __wcollate_range_cmp() which does work with wide
characters. This function is used only internally in libc so
we don't export it. Use the new function in glob(3), fnmatch(3),
and regexec(3).
PR: 179721
Suggested by: ache. jilles
MFC after: 3 weeks (perhaps partial only)
Solaris and other OSs have support for \< and \> as word
delimiters in utilities like sed(1). These are useful to
have for general compatiblity with Solaris but should be
avoided for portability with other systems, including the
traditional BSDs.
Bump __FreeBSD_version as this is likely to affect some
userland utilities.
Reference:
https://www.illumos.org/issues/516
PR: bin/153257
Obtained from: Illumos
MFC after: 1 month
The code doesn't really benefit of using reallocf() in this case.
Also, the realloc() results being assigned temporary variable which
makes blind replacement with reallocf() mostly useless.
Pointed out by: stefanf, bde
Use of reallocf is useful in libraries as we are not certain the
application will exit after NULL.
This somewhat reduces portability but if since you are building
this as part of libc it is likely you have our non-standard
reallocf(3) already.
Reviewed by: ache
MFC after: 5 days
load of _l suffixed versions of various standard library functions that use
the global locale, making them take an explicit locale parameter. Also
adds support for per-thread locales. This work was funded by the FreeBSD
Foundation.
Please test any code you have that uses the C standard locale functions!
Reviewed by: das (gdtoa changes)
Approved by: dim (mentor)
multibyte character support:
- In CHadd(), avoid writing past the end of the character set bitmap when
the opposite-case counterpart of wide characters with values less than
NC have values greater than or equal to NC.
- In CHaddtype(), fix a braino that caused alphabetic characters to be
added to all character classes! (but only with REG_ICASE)
PR: 71367
idea is that we perform multibyte->wide character conversion while parsing
and compiling, then convert byte sequences to wide characters when they're
needed for comparison and stepping through the string during execution.
As with tr(1), the main complication is to efficiently represent sets of
characters in bracket expressions. The old bitmap representation is replaced
by a bitmap for the first 256 characters combined with a vector of individual
wide characters, a vector of character ranges (for [A-Z] etc.), and a vector
of character classes (for [[:alpha:]] etc.).
One other point of interest is that although the Boyer-Moore algorithm had
to be disabled in the general multibyte case, it is still enabled for UTF-8
because of its self-synchronizing nature. This greatly speeds up matching
by reducing the number of multibyte conversions that need to be done.
Only warnings that could be fixed without changing the generated object
code and without restructuring the source code have been handled.
Reviewed by: /sbin/md5
access an array beyond it's length. This only happens in the last iteration of
a loop, and the value fetched is not used then, so the bug is a relatively
innocent one. Fix this by not fetching any value on the last iteration of said
loop.
Submitted by: MKI <mki@mozone.net>
MFC after: 1 week
of the processing of the recursion, "scan" would be pointing to O_CH
(or O_QUEST), which would then be interpreted as being the end character
for altoffset().
We avoid this by properly increasing scan before leaving the switch.
Without this, something like (a?b?)?cc would result in a g->moffset of
1 instead of 2.
I added a case to the soon-to-be-imported regex(3) test code to catch
this error.
use a CHAR_MIN-based array, like elsewhere in the code.
Remove a number of unused variables (some due to the above change, one
that was left after a number of optimizing steps through the source).
Brucified by: bde
previous commits.
At the time we search the pattern for the "must" string, we now compute
the longest offset from the beginning of the pattern at which the must
string might be found. If that offset is found to be infinite (through
use of "+" or "*"), we set it to -1 to disable the heuristics applied
later.
After we are done with pre-matching, we use that offset and the point in
the text at which the must string was found to compute the earliest
point at which the pattern might be found.
Special care should be taken here. The variable "start" is passed to the
automata-processing functions fast() and slow() to indicate the point in
the text at which they should start working from. The real beginning of
the text is passed in a struct match variable m, which is used to check
for anchors. That variable, though, is initialized with "start", so we
must not adjust "start" before "m" is properly initialized.
Simple tests showed a speed increase from 100% to 400%, but they were
biased in that regexec() was called for the whole file instead of line
by line, and parenthized subexpressions were not searched for.
This change adds a single integer to the size of the "guts" structure,
and does not change the ABI.
Further improvements possible:
Since the speed increase observed here is so huge, one intuitive
optimization would be to introduce a bias in the function that computes
the "must" string so as to prefer a smaller string with a finite offset
over a larger one with an infinite offset. Tests have shown this to be a
bad idea, though, as the cost of false pre-matches far outweights the
benefits of a must offset, even in biased situations.
A number of other improvements suggest themselves, though:
* identify the cases where the pattern is identical to the must
string, and avoid entering fast() and slow() in these cases.
* compute the maximum offset from the must string to the end of
the pattern, and use that to set the point at which fast() and
slow() should give up trying to find a match, and return then
return to pre-matching.
* return all the way to pre-matching if a "match" was found and
later invalidated by back reference processing. Since back
references are evil and should be avoided anyway, this is of
little use.
The BM algorithm works by scanning the pattern from right to left,
and jumping as many characters as viable based on the text's mismatched
character and the pattern's already matched suffix.
This typically enable us to test only a fraction of the text's characters,
but has a worse performance than the straight-forward method for small
patterns. Because of this, the BM algorithm will only be used if the
pattern size is at least 4 characters.
Notice that this pre-matching is done on the largest substring of the
regular expression that _must_ be present on the text for a succesful
match to be possible at all.
For instance, "(xyzzy|grues)" will yield a null "must" substring, and,
therefore, not benefit from the BM algorithm at all. Because of the
lack of intelligence of the algorithm that finds the "must" string,
things like "charjump|matchjump" will also yield a null string. To
optimize that, "(char|match)jump" should be used.
The setup time (at regcomp()) for the BM algorithm will most likely
outweight any benefits for one-time matches. Given the slow regex(3)
we have, this is unlikely to be even perceptible, though.
The size of a regex_t structure is increased by 2*sizeof(char*) +
256*sizeof(int) + strlen(must)*sizeof(int). This is all inside the
regex_t's "guts", which is allocated dynamically by regcomp(). If
allocation of either of the two tables fail, the other one is freed.
In this case, the straight-forward algorithm is used for pre-matching.
Tests exercising the code path affected have shown a speed increase of
50% for "must" strings of length four or five.
API and ABI remain unchanged by this commit.
The patch submitted on the PR was not used, as it was non-functional.
PR: 14342
