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Regex: Update PCRE to v8.35.

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I was über lazy at first, so took libs from SM.
But actually it's quite easy to compile, so let's update to latest version \o/.
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Arkshine
2014-07-05 13:53:30 +02:00
parent d1153b8049
commit d4de0e6f1e
241 changed files with 51074 additions and 15011 deletions
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269
tools/pcre/HACKING
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@ -54,12 +54,12 @@ Support for 16-bit and 32-bit data strings
From release 8.30, PCRE supports 16-bit as well as 8-bit data strings; and from
release 8.32, PCRE supports 32-bit data strings. The library can be compiled
in any combination of 8-bit, 16-bit or 32-bit modes, creating different
libraries. In the description that follows, the word "short" is
used for a 16-bit data quantity, and the word "unit" is used for a quantity
that is a byte in 8-bit mode, a short in 16-bit mode and a 32-bit unsigned
integer in 32-bit mode. However, so as not to over-complicate the text, the
names of PCRE functions are given in 8-bit form only.
in any combination of 8-bit, 16-bit or 32-bit modes, creating up to three
different libraries. In the description that follows, the word "short" is used
for a 16-bit data quantity, and the word "unit" is used for a quantity that is
a byte in 8-bit mode, a short in 16-bit mode and a 32-bit word in 32-bit mode.
However, so as not to over-complicate the text, the names of PCRE functions are
given in 8-bit form only.
Computing the memory requirement: how it was
@ -94,6 +94,11 @@ runs more slowly than before (30% or more, depending on the pattern) because it
is doing a full analysis of the pattern. My hope was that this would not be a
big issue, and in the event, nobody has commented on it.
At release 8.34, a limit on the nesting depth of parentheses was re-introduced
(default 250, settable at build time) so as to put a limit on the amount of
system stack used by pcre_compile(). This is a safety feature for environments
with small stacks where the patterns are provided by users.
Traditional matching function
-----------------------------
@ -120,29 +125,30 @@ facilities are available, and those that are do not always work in quite the
same way. See the user documentation for details.
The algorithm that is used for pcre_dfa_exec() is not a traditional FSM,
because it may have a number of states active at one time. More work would be
needed at compile time to produce a traditional FSM where only one state is
ever active at once. I believe some other regex matchers work this way.
because it may have a number of states active at one time. More work would be
needed at compile time to produce a traditional FSM where only one state is
ever active at once. I believe some other regex matchers work this way. JIT
support is not available for this kind of matching.
Changeable options
------------------
The /i, /m, or /s options (PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL) may
change in the middle of patterns. From PCRE 8.13, their processing is handled
entirely at compile time by generating different opcodes for the different
settings. The runtime functions do not need to keep track of an options state
any more.
The /i, /m, or /s options (PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and some
others) may change in the middle of patterns. From PCRE 8.13, their processing
is handled entirely at compile time by generating different opcodes for the
different settings. The runtime functions do not need to keep track of an
options state any more.
Format of compiled patterns
---------------------------
The compiled form of a pattern is a vector of units (bytes in 8-bit mode, or
shorts in 16-bit mode, 32-bit unsigned integers in 32-bit mode), containing
items of variable length. The first unit in an item contains an opcode, and
the length of the item is either implicit in the opcode or contained in the
data that follows it.
The compiled form of a pattern is a vector of unsigned units (bytes in 8-bit
mode, shorts in 16-bit mode, 32-bit words in 32-bit mode), containing items of
variable length. The first unit in an item contains an opcode, and the length
of the item is either implicit in the opcode or contained in the data that
follows it.
In many cases listed below, LINK_SIZE data values are specified for offsets
within the compiled pattern. LINK_SIZE always specifies a number of bytes. The
@ -151,8 +157,10 @@ default value for LINK_SIZE is 2, but PCRE can be compiled to use 3-byte or
LINK_SIZE values are available only in 8-bit mode.) Specifing a LINK_SIZE
larger than 2 is necessary only when patterns whose compiled length is greater
than 64K are going to be processed. In this description, we assume the "normal"
compilation options. Data values that are counts (e.g. for quantifiers) are
always just two bytes long (one short in 16-bit mode).
compilation options. Data values that are counts (e.g. quantifiers) are two
bytes long in 8-bit mode (most significant byte first), or one unit in 16-bit
and 32-bit modes.
Opcodes with no following data
------------------------------
@ -162,7 +170,7 @@ These items are all just one unit long
OP_END end of pattern
OP_ANY match any one character other than newline
OP_ALLANY match any one character, including newline
OP_ANYBYTE match any single byte, even in UTF-8 mode
OP_ANYBYTE match any single unit, even in UTF-8/16 mode
OP_SOD match start of data: \A
OP_SOM, start of match (subject + offset): \G
OP_SET_SOM, set start of match (\K)
@ -180,28 +188,33 @@ These items are all just one unit long
OP_VSPACE \v
OP_NOT_WORDCHAR \W
OP_WORDCHAR \w
OP_EODN match end of data or \n at end: \Z
OP_EODN match end of data or newline at end: \Z
OP_EOD match end of data: \z
OP_DOLL $ (end of data, or before final newline)
OP_DOLLM $ multiline mode (end of data or before newline)
OP_EXTUNI match an extended Unicode character
OP_EXTUNI match an extended Unicode grapheme cluster
OP_ANYNL match any Unicode newline sequence
OP_ASSERT_ACCEPT )
OP_ACCEPT ) These are Perl 5.10's "backtracking control
OP_COMMIT ) verbs". If OP_ACCEPT is inside capturing
OP_FAIL ) parentheses, it may be preceded by one or more
OP_PRUNE ) OP_CLOSE, followed by a 2-byte number,
OP_SKIP ) indicating which parentheses must be closed.
OP_PRUNE ) OP_CLOSE, each followed by a count that
OP_SKIP ) indicates which parentheses must be closed.
OP_THEN )
OP_ASSERT_ACCEPT is used when (*ACCEPT) is encountered within an assertion.
This ends the assertion, not the entire pattern match.
Backtracking control verbs with (optional) data
-----------------------------------------------
Backtracking control verbs with optional data
---------------------------------------------
(*THEN) without an argument generates the opcode OP_THEN and no following data.
OP_MARK is followed by the mark name, preceded by a one-unit length, and
followed by a binary zero. For (*PRUNE), (*SKIP), and (*THEN) with arguments,
the opcodes OP_PRUNE_ARG, OP_SKIP_ARG, and OP_THEN_ARG are used, with the name
following in the same format.
following in the same format as OP_MARK.
Matching literal characters
@ -212,6 +225,10 @@ casefully. For caseless matching, OP_CHARI is used. In UTF-8 or UTF-16 modes,
the character may be more than one unit long. In UTF-32 mode, characters
are always exactly one unit long.
If there is only one character in a character class, OP_CHAR or OP_CHARI is
used for a positive class, and OP_NOT or OP_NOTI for a negative one (that is,
for something like [^a]).
Repeating single characters
---------------------------
@ -232,10 +249,9 @@ following opcodes, which come in caseful and caseless versions:
Each opcode is followed by the character that is to be repeated. In ASCII mode,
these are two-unit items; in UTF-8 or UTF-16 modes, the length is variable; in
UTF-32 mode these are one-unit items.
Those with "MIN" in their names are the minimizing versions. Those with "POS"
in their names are possessive versions. Other repeats make use of these
opcodes:
UTF-32 mode these are one-unit items. Those with "MIN" in their names are the
minimizing versions. Those with "POS" in their names are possessive versions.
Other repeats make use of these opcodes:
Caseful Caseless
OP_UPTO OP_UPTOI
@ -243,10 +259,15 @@ opcodes:
OP_POSUPTO OP_POSUPTOI
OP_EXACT OP_EXACTI
Each of these is followed by a two-byte (one short) count (most significant
byte first in 8-bit mode) and then the repeated character. OP_UPTO matches from
0 to the given number. A repeat with a non-zero minimum and a fixed maximum is
coded as an OP_EXACT followed by an OP_UPTO (or OP_MINUPTO or OPT_POSUPTO).
Each of these is followed by a count and then the repeated character. OP_UPTO
matches from 0 to the given number. A repeat with a non-zero minimum and a
fixed maximum is coded as an OP_EXACT followed by an OP_UPTO (or OP_MINUPTO or
OPT_POSUPTO).
Another set of matching repeating opcodes (called OP_NOTSTAR, OP_NOTSTARI,
etc.) are used for repeated, negated, single-character classes such as [^a]*.
The normal single-character opcodes (OP_STAR, etc.) are used for repeated
positive single-character classes.
Repeating character types
@ -277,7 +298,10 @@ Match by Unicode property
OP_PROP and OP_NOTPROP are used for positive and negative matches of a
character by testing its Unicode property (the \p and \P escape sequences).
Each is followed by two units that encode the desired property as a type and a
value.
value. The types are a set of #defines of the form PT_xxx, and the values are
enumerations of the form ucp_xx, defined in the ucp.h source file. The value is
relevant only for PT_GC (General Category), PT_PC (Particular Category), and
PT_SC (Script).
Repeats of these items use the OP_TYPESTAR etc. set of opcodes, followed by
three units: OP_PROP or OP_NOTPROP, and then the desired property type and
@ -287,67 +311,88 @@ value.
Character classes
-----------------
If there is only one character in the class, OP_CHAR or OP_CHARI is used for a
If there is only one character in a class, OP_CHAR or OP_CHARI is used for a
positive class, and OP_NOT or OP_NOTI for a negative one (that is, for
something like [^a]).
Another set of 13 repeating opcodes (called OP_NOTSTAR etc.) are used for
repeated, negated, single-character classes. The normal single-character
opcodes (OP_STAR, etc.) are used for repeated positive single-character
classes.
A set of repeating opcodes (called OP_NOTSTAR etc.) are used for repeated,
negated, single-character classes. The normal single-character opcodes
(OP_STAR, etc.) are used for repeated positive single-character classes.
When there is more than one character in a class and all the characters are
When there is more than one character in a class, and all the code points are
less than 256, OP_CLASS is used for a positive class, and OP_NCLASS for a
negative one. In either case, the opcode is followed by a 32-byte (16-short)
bit map containing a 1 bit for every character that is acceptable. The bits are
counted from the least significant end of each unit. In caseless mode, bits for
both cases are set.
negative one. In either case, the opcode is followed by a 32-byte (16-short,
8-word) bit map containing a 1 bit for every character that is acceptable. The
bits are counted from the least significant end of each unit. In caseless mode,
bits for both cases are set.
The reason for having both OP_CLASS and OP_NCLASS is so that, in UTF-8/16/32 mode,
subject characters with values greater than 255 can be handled correctly. For
OP_CLASS they do not match, whereas for OP_NCLASS they do.
The reason for having both OP_CLASS and OP_NCLASS is so that, in UTF-8/16/32
mode, subject characters with values greater than 255 can be handled correctly.
For OP_CLASS they do not match, whereas for OP_NCLASS they do.
For classes containing characters with values greater than 255, OP_XCLASS is
used. It optionally uses a bit map (if any characters lie within it), followed
by a list of pairs (for a range) and single characters. In caseless mode, both
cases are explicitly listed. There is a flag character than indicates whether
it is a positive or a negative class.
For classes containing characters with values greater than 255 or that contain
\p or \P, OP_XCLASS is used. It optionally uses a bit map if any code points
are less than 256, followed by a list of pairs (for a range) and single
characters. In caseless mode, both cases are explicitly listed.
OP_XCLASS is followed by a unit containing flag bits: XCL_NOT indicates that
this is a negative class, and XCL_MAP indicates that a bit map is present.
There follows the bit map, if XCL_MAP is set, and then a sequence of items
coded as follows:
XCL_END marks the end of the list
XCL_SINGLE one character follows
XCL_RANGE two characters follow
XCL_PROP a Unicode property (type, value) follows
XCL_NOTPROP a Unicode property (type, value) follows
If a range starts with a code point less than 256 and ends with one greater
than 256, an XCL_RANGE item is used, without setting any bits in the bit map.
This means that if no other items in the class set bits in the map, a map is
not needed.
Back references
---------------
OP_REF (caseful) or OP_REFI (caseless) is followed by two bytes (one short)
containing the reference number.
OP_REF (caseful) or OP_REFI (caseless) is followed by a count containing the
reference number if the reference is to a unique capturing group (either by
number or by name). When named groups are used, there may be more than one
group with the same name. In this case, a reference by name generates OP_DNREF
or OP_DNREFI. These are followed by two counts: the index (not the byte offset)
in the group name table of the first entry for the requred name, followed by
the number of groups with the same name.
Repeating character classes and back references
-----------------------------------------------
Single-character classes are handled specially (see above). This section
applies to OP_CLASS and OP_REF[I]. In both cases, the repeat information
follows the base item. The matching code looks at the following opcode to see
if it is one of
applies to other classes and also to back references. In both cases, the repeat
information follows the base item. The matching code looks at the following
opcode to see if it is one of
OP_CRSTAR
OP_CRMINSTAR
OP_CRPOSSTAR
OP_CRPLUS
OP_CRMINPLUS
OP_CRPOSPLUS
OP_CRQUERY
OP_CRMINQUERY
OP_CRPOSQUERY
OP_CRRANGE
OP_CRMINRANGE
OP_CRPOSRANGE
All but the last two are just single-unit items. The others are followed by
four bytes (two shorts) of data, comprising the minimum and maximum repeat
counts. There are no special possessive opcodes for these repeats; a possessive
repeat is compiled into an atomic group.
All but the last three are single-unit items, with no data. The others are
followed by the minimum and maximum repeat counts.
Brackets and alternation
------------------------
A pair of non-capturing (round) brackets is wrapped round each expression at
A pair of non-capturing round brackets is wrapped round each expression at
compile time, so alternation always happens in the context of brackets.
[Note for North Americans: "bracket" to some English speakers, including
@ -364,20 +409,20 @@ A bracket opcode is followed by LINK_SIZE bytes which give the offset to the
next alternative OP_ALT or, if there aren't any branches, to the matching
OP_KET opcode. Each OP_ALT is followed by LINK_SIZE bytes giving the offset to
the next one, or to the OP_KET opcode. For capturing brackets, the bracket
number immediately follows the offset, always as a 2-byte (one short) item.
number is a count that immediately follows the offset.
OP_KET is used for subpatterns that do not repeat indefinitely, and
OP_KETRMIN and OP_KETRMAX are used for indefinite repetitions, minimally or
maximally respectively (see below for possessive repetitions). All three are
followed by LINK_SIZE bytes giving (as a positive number) the offset back to
the matching bracket opcode.
OP_KET is used for subpatterns that do not repeat indefinitely, and OP_KETRMIN
and OP_KETRMAX are used for indefinite repetitions, minimally or maximally
respectively (see below for possessive repetitions). All three are followed by
LINK_SIZE bytes giving (as a positive number) the offset back to the matching
bracket opcode.
If a subpattern is quantified such that it is permitted to match zero times, it
is preceded by one of OP_BRAZERO, OP_BRAMINZERO, or OP_SKIPZERO. These are
single-unit opcodes that tell the matcher that skipping the following
subpattern entirely is a valid branch. In the case of the first two, not
skipping the pattern is also valid (greedy and non-greedy). The third is used
when a pattern has the quantifier {0,0}. It cannot be entirely discarded,
when a pattern has the quantifier {0,0}. It cannot be entirely discarded,
because it may be called as a subroutine from elsewhere in the regex.
A subpattern with an indefinite maximum repetition is replicated in the
@ -397,6 +442,7 @@ final replication is changed to OP_SBRA or OP_SCBRA. This tells the matcher
that it needs to check for matching an empty string when it hits OP_KETRMIN or
OP_KETRMAX, and if so, to break the loop.
Possessive brackets
-------------------
@ -407,26 +453,34 @@ of OP_SCBRA. The end of such a group is marked by OP_KETRPOS. If the minimum
repetition is zero, the group is preceded by OP_BRAPOSZERO.
Once-only (atomic) groups
-------------------------
These are just like other subpatterns, but they start with the opcode
OP_ONCE or OP_ONCE_NC. The former is used when there are no capturing brackets
within the atomic group; the latter when there are. The distinction is needed
for when there is a backtrack to before the group - any captures within the
group must be reset, so it is necessary to retain backtracking points inside
the group even after it is complete in order to do this. When there are no
captures in an atomic group, all the backtracking can be discarded when it is
complete. This is more efficient, and also uses less stack.
The check for matching an empty string in an unbounded repeat is handled
entirely at runtime, so there are just these two opcodes for atomic groups.
Assertions
----------
Forward assertions are just like other subpatterns, but starting with one of
the opcodes OP_ASSERT or OP_ASSERT_NOT. Backward assertions use the opcodes
Forward assertions are also just like other subpatterns, but starting with one
of the opcodes OP_ASSERT or OP_ASSERT_NOT. Backward assertions use the opcodes
OP_ASSERTBACK and OP_ASSERTBACK_NOT, and the first opcode inside the assertion
is OP_REVERSE, followed by a two byte (one short) count of the number of
characters to move back the pointer in the subject string. In ASCII mode, the
count is a number of units, but in UTF-8/16 mode each character may occupy more
than one unit; in UTF-32 mode each character occupies exactly one unit.
A separate count is present in each alternative of a lookbehind
assertion, allowing them to have different fixed lengths.
Once-only (atomic) subpatterns
------------------------------
These are also just like other subpatterns, but they start with the opcode
OP_ONCE. The check for matching an empty string in an unbounded repeat is
handled entirely at runtime, so there is just this one opcode.
is OP_REVERSE, followed by a count of the number of characters to move back the
pointer in the subject string. In ASCII mode, the count is a number of units,
but in UTF-8/16 mode each character may occupy more than one unit; in UTF-32
mode each character occupies exactly one unit. A separate count is present in
each alternative of a lookbehind assertion, allowing them to have different
fixed lengths.
Conditional subpatterns
@ -435,28 +489,29 @@ Conditional subpatterns
These are like other subpatterns, but they start with the opcode OP_COND, or
OP_SCOND for one that might match an empty string in an unbounded repeat. If
the condition is a back reference, this is stored at the start of the
subpattern using the opcode OP_CREF followed by two bytes (one short)
containing the reference number. OP_NCREF is used instead if the reference was
generated by name (so that the runtime code knows to check for duplicate
names).
subpattern using the opcode OP_CREF followed by a count containing the
reference number, provided that the reference is to a unique capturing group.
If the reference was by name and there is more than one group with that name,
OP_DNCREF is used instead. It is followed by two counts: the index in the group
names table, and the number of groups with the same name.
If the condition is "in recursion" (coded as "(?(R)"), or "in recursion of
group x" (coded as "(?(Rx)"), the group number is stored at the start of the
subpattern using the opcode OP_RREF or OP_NRREF (cf OP_NCREF), and a value of
zero for "the whole pattern". For a DEFINE condition, just the single unit
OP_DEF is used (it has no associated data). Otherwise, a conditional subpattern
always starts with one of the assertions.
subpattern using the opcode OP_RREF (with a value of zero for "the whole
pattern") or OP_DNRREF (with data as for OP_DNCREF). For a DEFINE condition,
just the single unit OP_DEF is used (it has no associated data). Otherwise, a
conditional subpattern always starts with one of the assertions.
Recursion
---------
Recursion either matches the current regex, or some subexpression. The opcode
OP_RECURSE is followed by an value which is the offset to the starting bracket
from the start of the whole pattern. From release 6.5, OP_RECURSE is
automatically wrapped inside OP_ONCE brackets (because otherwise some patterns
broke it). OP_RECURSE is also used for "subroutine" calls, even though they
are not strictly a recursion.
OP_RECURSE is followed by aLINK_SIZE value that is the offset to the starting
bracket from the start of the whole pattern. From release 6.5, OP_RECURSE is
automatically wrapped inside OP_ONCE brackets, because otherwise some patterns
broke it. OP_RECURSE is also used for "subroutine" calls, even though they are
not strictly a recursion.
Callout
@ -464,10 +519,10 @@ Callout
OP_CALLOUT is followed by one unit of data that holds a callout number in the
range 0 to 254 for manual callouts, or 255 for an automatic callout. In both
cases there follows a two-byte (one short) value giving the offset in the
pattern to the start of the following item, and another two-byte (one short)
item giving the length of the next item.
cases there follows a count giving the offset in the pattern string to the
start of the following item, and another count giving the length of this item.
These values make is possible for pcretest to output useful tracing information
using automatic callouts.
Philip Hazel
February 2012
November 2013