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openldap/libraries/liblunicode/ure/ure.c
Quanah Gibson-Mount f6ad222e41 Happy New Year!
2020-01-09 16:50:21 +00:00

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/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 1998-2020 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/* Copyright 1997, 1998, 1999 Computing Research Labs,
* New Mexico State University
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COMPUTING RESEARCH LAB OR NEW MEXICO STATE UNIVERSITY BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
* OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
* THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/* $Id: ure.c,v 1.2 1999/09/21 15:47:43 mleisher Exp $" */
#include "portable.h"
#include <ac/stdlib.h>
#include <ac/string.h>
#include <ac/unistd.h>
#include "ure.h"
/*
* Flags used internally in the DFA.
*/
#define _URE_DFA_CASEFOLD 0x01
#define _URE_DFA_BLANKLINE 0x02
static unsigned long cclass_flags[] = {
0,
_URE_NONSPACING,
_URE_COMBINING,
_URE_NUMDIGIT,
_URE_NUMOTHER,
_URE_SPACESEP,
_URE_LINESEP,
_URE_PARASEP,
_URE_CNTRL,
_URE_PUA,
_URE_UPPER,
_URE_LOWER,
_URE_TITLE,
_URE_MODIFIER,
_URE_OTHERLETTER,
_URE_DASHPUNCT,
_URE_OPENPUNCT,
_URE_CLOSEPUNCT,
_URE_OTHERPUNCT,
_URE_MATHSYM,
_URE_CURRENCYSYM,
_URE_OTHERSYM,
_URE_LTR,
_URE_RTL,
_URE_EURONUM,
_URE_EURONUMSEP,
_URE_EURONUMTERM,
_URE_ARABNUM,
_URE_COMMONSEP,
_URE_BLOCKSEP,
_URE_SEGMENTSEP,
_URE_WHITESPACE,
_URE_OTHERNEUT,
};
/*
* Symbol types for the DFA.
*/
#define _URE_ANY_CHAR 1
#define _URE_CHAR 2
#define _URE_CCLASS 3
#define _URE_NCCLASS 4
#define _URE_BOL_ANCHOR 5
#define _URE_EOL_ANCHOR 6
/*
* Op codes for converting the NFA to a DFA.
*/
#define _URE_SYMBOL 10
#define _URE_PAREN 11
#define _URE_QUEST 12
#define _URE_STAR 13
#define _URE_PLUS 14
#define _URE_ONE 15
#define _URE_AND 16
#define _URE_OR 17
#define _URE_NOOP 0xffff
#define _URE_REGSTART 0x8000
#define _URE_REGEND 0x4000
/*
* Structure used to handle a compacted range of characters.
*/
typedef struct {
ucs4_t min_code;
ucs4_t max_code;
} _ure_range_t;
typedef struct {
_ure_range_t *ranges;
ucs2_t ranges_used;
ucs2_t ranges_size;
} _ure_ccl_t;
typedef union {
ucs4_t chr;
_ure_ccl_t ccl;
} _ure_sym_t;
/*
* This is a general element structure used for expressions and stack
* elements.
*/
typedef struct {
ucs2_t reg;
ucs2_t onstack;
ucs2_t type;
ucs2_t lhs;
ucs2_t rhs;
} _ure_elt_t;
/*
* This is a structure used to track a list or a stack of states.
*/
typedef struct {
ucs2_t *slist;
ucs2_t slist_size;
ucs2_t slist_used;
} _ure_stlist_t;
/*
* Structure to track the list of unique states for a symbol
* during reduction.
*/
typedef struct {
ucs2_t id;
ucs2_t type;
unsigned long mods;
unsigned long props;
_ure_sym_t sym;
_ure_stlist_t states;
} _ure_symtab_t;
/*
* Structure to hold a single state.
*/
typedef struct {
ucs2_t id;
ucs2_t accepting;
ucs2_t pad;
_ure_stlist_t st;
_ure_elt_t *trans;
ucs2_t trans_size;
ucs2_t trans_used;
} _ure_state_t;
/*
* Structure used for keeping lists of states.
*/
typedef struct {
_ure_state_t *states;
ucs2_t states_size;
ucs2_t states_used;
} _ure_statetable_t;
/*
* Structure to track pairs of DFA states when equivalent states are
* merged.
*/
typedef struct {
ucs2_t l;
ucs2_t r;
} _ure_equiv_t;
/*
* Structure used for constructing the NFA and reducing to a minimal DFA.
*/
typedef struct _ure_buffer_t {
int reducing;
int error;
unsigned long flags;
_ure_stlist_t stack;
/*
* Table of unique symbols encountered.
*/
_ure_symtab_t *symtab;
ucs2_t symtab_size;
ucs2_t symtab_used;
/*
* Tracks the unique expressions generated for the NFA and when the NFA is
* reduced.
*/
_ure_elt_t *expr;
ucs2_t expr_used;
ucs2_t expr_size;
/*
* The reduced table of unique groups of NFA states.
*/
_ure_statetable_t states;
/*
* Tracks states when equivalent states are merged.
*/
_ure_equiv_t *equiv;
ucs2_t equiv_used;
ucs2_t equiv_size;
} _ure_buffer_t;
typedef struct {
ucs2_t symbol;
ucs2_t next_state;
} _ure_trans_t;
typedef struct {
ucs2_t accepting;
ucs2_t ntrans;
_ure_trans_t *trans;
} _ure_dstate_t;
typedef struct _ure_dfa_t {
unsigned long flags;
_ure_symtab_t *syms;
ucs2_t nsyms;
_ure_dstate_t *states;
ucs2_t nstates;
_ure_trans_t *trans;
ucs2_t ntrans;
} _ure_dfa_t;
/*************************************************************************
*
* Functions.
*
*************************************************************************/
static void
_ure_memmove(char *dest, char *src, unsigned long bytes)
{
long i, j;
i = (long) bytes;
j = i & 7;
i = (i + 7) >> 3;
/*
* Do a memmove using Ye Olde Duff's Device for efficiency.
*/
if (src < dest) {
src += bytes;
dest += bytes;
switch (j) {
case 0: do {
*--dest = *--src;
case 7: *--dest = *--src;
case 6: *--dest = *--src;
case 5: *--dest = *--src;
case 4: *--dest = *--src;
case 3: *--dest = *--src;
case 2: *--dest = *--src;
case 1: *--dest = *--src;
} while (--i > 0);
}
} else if (src > dest) {
switch (j) {
case 0: do {
*dest++ = *src++;
case 7: *dest++ = *src++;
case 6: *dest++ = *src++;
case 5: *dest++ = *src++;
case 4: *dest++ = *src++;
case 3: *dest++ = *src++;
case 2: *dest++ = *src++;
case 1: *dest++ = *src++;
} while (--i > 0);
}
}
}
static void
_ure_push(ucs2_t v, _ure_buffer_t *b)
{
_ure_stlist_t *s;
if (b == 0)
return;
/*
* If the `reducing' parameter is non-zero, check to see if the value
* passed is already on the stack.
*/
if (b->reducing != 0 && b->expr[v].onstack != 0)
return;
s = &b->stack;
if (s->slist_used == s->slist_size) {
if (s->slist_size == 0)
s->slist = (ucs2_t *) malloc(sizeof(ucs2_t) << 3);
else
s->slist = (ucs2_t *) realloc((char *) s->slist,
sizeof(ucs2_t) * (s->slist_size + 8));
s->slist_size += 8;
}
s->slist[s->slist_used++] = v;
/*
* If the `reducing' parameter is non-zero, flag the element as being on
* the stack.
*/
if (b->reducing != 0)
b->expr[v].onstack = 1;
}
static ucs2_t
_ure_peek(_ure_buffer_t *b)
{
if (b == 0 || b->stack.slist_used == 0)
return _URE_NOOP;
return b->stack.slist[b->stack.slist_used - 1];
}
static ucs2_t
_ure_pop(_ure_buffer_t *b)
{
ucs2_t v;
if (b == 0 || b->stack.slist_used == 0)
return _URE_NOOP;
v = b->stack.slist[--b->stack.slist_used];
if (b->reducing)
b->expr[v].onstack = 0;
return v;
}
/*************************************************************************
*
* Start symbol parse functions.
*
*************************************************************************/
/*
* Parse a comma-separated list of integers that represent character
* properties. Combine them into a mask that is returned in the `mask'
* variable, and return the number of characters consumed.
*/
static unsigned long
_ure_prop_list(ucs2_t *pp, unsigned long limit, unsigned long *mask,
_ure_buffer_t *b)
{
unsigned long n, m;
ucs2_t *sp, *ep;
sp = pp;
ep = sp + limit;
for (m = n = 0; b->error == _URE_OK && sp < ep; sp++) {
if (*sp == ',') {
/*
* Encountered a comma, so select the next character property flag
* and reset the number.
*/
m |= cclass_flags[n];
n = 0;
} else if (*sp >= '0' && *sp <= '9')
/*
* Encountered a digit, so start or continue building the cardinal
* that represents the character property flag.
*/
n = (n * 10) + (*sp - '0');
else
/*
* Encountered something that is not part of the property list.
* Indicate that we are done.
*/
break;
/*
* If a property number greater than 32 occurs, then there is a
* problem. Most likely a missing comma separator.
*/
if (n > 32)
b->error = _URE_INVALID_PROPERTY;
}
if (b->error == _URE_OK && n != 0)
m |= cclass_flags[n];
/*
* Set the mask that represents the group of character properties.
*/
*mask = m;
/*
* Return the number of characters consumed.
*/
return sp - pp;
}
/*
* Collect a hex number with 1 to 4 digits and return the number
* of characters used.
*/
static unsigned long
_ure_hex(ucs2_t *np, unsigned long limit, ucs4_t *n)
{
ucs2_t i;
ucs2_t *sp, *ep;
ucs4_t nn;
sp = np;
ep = sp + limit;
for (nn = 0, i = 0; i < 4 && sp < ep; i++, sp++) {
if (*sp >= '0' && *sp <= '9')
nn = (nn << 4) + (*sp - '0');
else if (*sp >= 'A' && *sp <= 'F')
nn = (nn << 4) + ((*sp - 'A') + 10);
else if (*sp >= 'a' && *sp <= 'f')
nn = (nn << 4) + ((*sp - 'a') + 10);
else
/*
* Encountered something that is not a hex digit.
*/
break;
}
/*
* Assign the character code collected and return the number of
* characters used.
*/
*n = nn;
return sp - np;
}
/*
* Insert a range into a character class, removing duplicates and ordering
* them in increasing range-start order.
*/
static void
_ure_add_range(_ure_ccl_t *ccl, _ure_range_t *r, _ure_buffer_t *b)
{
ucs2_t i;
ucs4_t tmp;
_ure_range_t *rp;
/*
* If the `casefold' flag is set, then make sure both endpoints of the
* range are converted to lower case.
*/
if (b->flags & _URE_DFA_CASEFOLD) {
r->min_code = _ure_tolower(r->min_code);
r->max_code = _ure_tolower(r->max_code);
}
/*
* Swap the range endpoints if they are not in increasing order.
*/
if (r->min_code > r->max_code) {
tmp = r->min_code;
r->min_code = r->max_code;
r->max_code = tmp;
}
for (i = 0, rp = ccl->ranges;
i < ccl->ranges_used && r->min_code < rp->min_code; i++, rp++) ;
/*
* Check for a duplicate.
*/
if (i < ccl->ranges_used &&
r->min_code == rp->min_code && r->max_code == rp->max_code)
return;
if (ccl->ranges_used == ccl->ranges_size) {
if (ccl->ranges_size == 0)
ccl->ranges = (_ure_range_t *) malloc(sizeof(_ure_range_t) << 3);
else
ccl->ranges = (_ure_range_t *)
realloc((char *) ccl->ranges,
sizeof(_ure_range_t) * (ccl->ranges_size + 8));
ccl->ranges_size += 8;
}
rp = ccl->ranges + ccl->ranges_used;
if (i < ccl->ranges_used)
_ure_memmove((char *) (rp + 1), (char *) rp,
sizeof(_ure_range_t) * (ccl->ranges_used - i));
ccl->ranges_used++;
rp->min_code = r->min_code;
rp->max_code = r->max_code;
}
#define _URE_ALPHA_MASK (_URE_UPPER|_URE_LOWER|_URE_OTHERLETTER|\
_URE_MODIFIER|_URE_TITLE|_URE_NONSPACING|_URE_COMBINING)
#define _URE_ALNUM_MASK (_URE_ALPHA_MASK|_URE_NUMDIGIT)
#define _URE_PUNCT_MASK (_URE_DASHPUNCT|_URE_OPENPUNCT|_URE_CLOSEPUNCT|\
_URE_OTHERPUNCT)
#define _URE_GRAPH_MASK (_URE_NUMDIGIT|_URE_NUMOTHER|_URE_ALPHA_MASK|\
_URE_MATHSYM|_URE_CURRENCYSYM|_URE_OTHERSYM)
#define _URE_PRINT_MASK (_URE_GRAPH_MASK|_URE_SPACESEP)
#define _URE_SPACE_MASK (_URE_SPACESEP|_URE_LINESEP|_URE_PARASEP)
typedef void (*_ure_cclsetup_t)(
_ure_symtab_t *sym,
unsigned long mask,
_ure_buffer_t *b
);
typedef struct {
ucs2_t key;
unsigned long len;
unsigned long next;
_ure_cclsetup_t func;
unsigned long mask;
} _ure_trie_t;
static void
_ure_ccl_setup(_ure_symtab_t *sym, unsigned long mask, _ure_buffer_t *b)
{
sym->props |= mask;
}
static void
_ure_space_setup(_ure_symtab_t *sym, unsigned long mask, _ure_buffer_t *b)
{
_ure_range_t range;
sym->props |= mask;
/*
* Add the additional characters needed for handling isspace().
*/
range.min_code = range.max_code = '\t';
_ure_add_range(&sym->sym.ccl, &range, b);
range.min_code = range.max_code = '\r';
_ure_add_range(&sym->sym.ccl, &range, b);
range.min_code = range.max_code = '\n';
_ure_add_range(&sym->sym.ccl, &range, b);
range.min_code = range.max_code = '\f';
_ure_add_range(&sym->sym.ccl, &range, b);
range.min_code = range.max_code = 0xfeff;
_ure_add_range(&sym->sym.ccl, &range, b);
}
static void
_ure_xdigit_setup(_ure_symtab_t *sym, unsigned long mask, _ure_buffer_t *b)
{
_ure_range_t range;
/*
* Add the additional characters needed for handling isxdigit().
*/
range.min_code = '0';
range.max_code = '9';
_ure_add_range(&sym->sym.ccl, &range, b);
range.min_code = 'A';
range.max_code = 'F';
_ure_add_range(&sym->sym.ccl, &range, b);
range.min_code = 'a';
range.max_code = 'f';
_ure_add_range(&sym->sym.ccl, &range, b);
}
static _ure_trie_t cclass_trie[] = {
{0x003a, 1, 1, 0, 0},
{0x0061, 9, 10, 0, 0},
{0x0063, 8, 19, 0, 0},
{0x0064, 7, 24, 0, 0},
{0x0067, 6, 29, 0, 0},
{0x006c, 5, 34, 0, 0},
{0x0070, 4, 39, 0, 0},
{0x0073, 3, 49, 0, 0},
{0x0075, 2, 54, 0, 0},
{0x0078, 1, 59, 0, 0},
{0x006c, 1, 11, 0, 0},
{0x006e, 2, 13, 0, 0},
{0x0070, 1, 16, 0, 0},
{0x0075, 1, 14, 0, 0},
{0x006d, 1, 15, 0, 0},
{0x003a, 1, 16, _ure_ccl_setup, _URE_ALNUM_MASK},
{0x0068, 1, 17, 0, 0},
{0x0061, 1, 18, 0, 0},
{0x003a, 1, 19, _ure_ccl_setup, _URE_ALPHA_MASK},
{0x006e, 1, 20, 0, 0},
{0x0074, 1, 21, 0, 0},
{0x0072, 1, 22, 0, 0},
{0x006c, 1, 23, 0, 0},
{0x003a, 1, 24, _ure_ccl_setup, _URE_CNTRL},
{0x0069, 1, 25, 0, 0},
{0x0067, 1, 26, 0, 0},
{0x0069, 1, 27, 0, 0},
{0x0074, 1, 28, 0, 0},
{0x003a, 1, 29, _ure_ccl_setup, _URE_NUMDIGIT},
{0x0072, 1, 30, 0, 0},
{0x0061, 1, 31, 0, 0},
{0x0070, 1, 32, 0, 0},
{0x0068, 1, 33, 0, 0},
{0x003a, 1, 34, _ure_ccl_setup, _URE_GRAPH_MASK},
{0x006f, 1, 35, 0, 0},
{0x0077, 1, 36, 0, 0},
{0x0065, 1, 37, 0, 0},
{0x0072, 1, 38, 0, 0},
{0x003a, 1, 39, _ure_ccl_setup, _URE_LOWER},
{0x0072, 2, 41, 0, 0},
{0x0075, 1, 45, 0, 0},
{0x0069, 1, 42, 0, 0},
{0x006e, 1, 43, 0, 0},
{0x0074, 1, 44, 0, 0},
{0x003a, 1, 45, _ure_ccl_setup, _URE_PRINT_MASK},
{0x006e, 1, 46, 0, 0},
{0x0063, 1, 47, 0, 0},
{0x0074, 1, 48, 0, 0},
{0x003a, 1, 49, _ure_ccl_setup, _URE_PUNCT_MASK},
{0x0070, 1, 50, 0, 0},
{0x0061, 1, 51, 0, 0},
{0x0063, 1, 52, 0, 0},
{0x0065, 1, 53, 0, 0},
{0x003a, 1, 54, _ure_space_setup, _URE_SPACE_MASK},
{0x0070, 1, 55, 0, 0},
{0x0070, 1, 56, 0, 0},
{0x0065, 1, 57, 0, 0},
{0x0072, 1, 58, 0, 0},
{0x003a, 1, 59, _ure_ccl_setup, _URE_UPPER},
{0x0064, 1, 60, 0, 0},
{0x0069, 1, 61, 0, 0},
{0x0067, 1, 62, 0, 0},
{0x0069, 1, 63, 0, 0},
{0x0074, 1, 64, 0, 0},
{0x003a, 1, 65, _ure_xdigit_setup, 0},
};
/*
* Probe for one of the POSIX colon delimited character classes in the static
* trie.
*/
static unsigned long
_ure_posix_ccl(ucs2_t *cp, unsigned long limit, _ure_symtab_t *sym,
_ure_buffer_t *b)
{
int i;
unsigned long n;
_ure_trie_t *tp;
ucs2_t *sp, *ep;
/*
* If the number of characters left is less than 7, then this cannot be
* interpreted as one of the colon delimited classes.
*/
if (limit < 7)
return 0;
sp = cp;
ep = sp + limit;
tp = cclass_trie;
for (i = 0; sp < ep && i < 8; i++, sp++) {
n = tp->len;
for (; n > 0 && tp->key != *sp; tp++, n--) ;
if (n == 0)
return 0;
if (*sp == ':' && (i == 6 || i == 7)) {
sp++;
break;
}
if (sp + 1 < ep)
tp = cclass_trie + tp->next;
}
if (tp->func == 0)
return 0;
(*tp->func)(sym, tp->mask, b);
return sp - cp;
}
/*
* Construct a list of ranges and return the number of characters consumed.
*/
static unsigned long
_ure_cclass(ucs2_t *cp, unsigned long limit, _ure_symtab_t *symp,
_ure_buffer_t *b)
{
int range_end;
unsigned long n;
ucs2_t *sp, *ep;
ucs4_t c, last;
_ure_ccl_t *cclp;
_ure_range_t range;
sp = cp;
ep = sp + limit;
if (*sp == '^') {
symp->type = _URE_NCCLASS;
sp++;
} else
symp->type = _URE_CCLASS;
for (last = 0, range_end = 0;
b->error == _URE_OK && sp < ep && *sp != ']'; ) {
c = *sp++;
if (c == '\\') {
if (sp == ep) {
/*
* The EOS was encountered when expecting the reverse solidus
* to be followed by the character it is escaping. Set an
* error code and return the number of characters consumed up
* to this point.
*/
b->error = _URE_UNEXPECTED_EOS;
return sp - cp;
}
c = *sp++;
switch (c) {
case 'a':
c = 0x07;
break;
case 'b':
c = 0x08;
break;
case 'f':
c = 0x0c;
break;
case 'n':
c = 0x0a;
break;
case 'r':
c = 0x0d;
break;
case 't':
c = 0x09;
break;
case 'v':
c = 0x0b;
break;
case 'p':
case 'P':
sp += _ure_prop_list(sp, ep - sp, &symp->props, b);
/*
* Invert the bit mask of the properties if this is a negated
* character class or if 'P' is used to specify a list of
* character properties that should *not* match in a
* character class.
*/
if (c == 'P')
symp->props = ~symp->props;
continue;
break;
case 'x':
case 'X':
case 'u':
case 'U':
if (sp < ep &&
((*sp >= '0' && *sp <= '9') ||
(*sp >= 'A' && *sp <= 'F') ||
(*sp >= 'a' && *sp <= 'f')))
sp += _ure_hex(sp, ep - sp, &c);
}
} else if (c == ':') {
/*
* Probe for a POSIX colon delimited character class.
*/
sp--;
if ((n = _ure_posix_ccl(sp, ep - sp, symp, b)) == 0)
sp++;
else {
sp += n;
continue;
}
}
cclp = &symp->sym.ccl;
/*
* Check to see if the current character is a low surrogate that needs
* to be combined with a preceding high surrogate.
*/
if (last != 0) {
if (c >= 0xdc00 && c <= 0xdfff)
/*
* Construct the UTF16 character code.
*/
c = 0x10000 + (((last & 0x03ff) << 10) | (c & 0x03ff));
else {
/*
* Add the isolated high surrogate to the range.
*/
if (range_end == 1)
range.max_code = last & 0xffff;
else
range.min_code = range.max_code = last & 0xffff;
_ure_add_range(cclp, &range, b);
range_end = 0;
}
}
/*
* Clear the last character code.
*/
last = 0;
/*
* This slightly awkward code handles the different cases needed to
* construct a range.
*/
if (c >= 0xd800 && c <= 0xdbff) {
/*
* If the high surrogate is followed by a range indicator, simply
* add it as the range start. Otherwise, save it in case the next
* character is a low surrogate.
*/
if (*sp == '-') {
sp++;
range.min_code = c;
range_end = 1;
} else
last = c;
} else if (range_end == 1) {
range.max_code = c;
_ure_add_range(cclp, &range, b);
range_end = 0;
} else {
range.min_code = range.max_code = c;
if (*sp == '-') {
sp++;
range_end = 1;
} else
_ure_add_range(cclp, &range, b);
}
}
if (sp < ep && *sp == ']')
sp++;
else
/*
* The parse was not terminated by the character class close symbol
* (']'), so set an error code.
*/
b->error = _URE_CCLASS_OPEN;
return sp - cp;
}
/*
* Probe for a low surrogate hex code.
*/
static unsigned long
_ure_probe_ls(ucs2_t *ls, unsigned long limit, ucs4_t *c)
{
ucs4_t i, code;
ucs2_t *sp, *ep;
for (i = code = 0, sp = ls, ep = sp + limit; i < 4 && sp < ep; sp++) {
if (*sp >= '0' && *sp <= '9')
code = (code << 4) + (*sp - '0');
else if (*sp >= 'A' && *sp <= 'F')
code = (code << 4) + ((*sp - 'A') + 10);
else if (*sp >= 'a' && *sp <= 'f')
code = (code << 4) + ((*sp - 'a') + 10);
else
break;
}
*c = code;
return (0xdc00 <= code && code <= 0xdfff) ? sp - ls : 0;
}
static unsigned long
_ure_compile_symbol(ucs2_t *sym, unsigned long limit, _ure_symtab_t *symp,
_ure_buffer_t *b)
{
ucs4_t c;
ucs2_t *sp, *ep;
sp = sym;
ep = sym + limit;
if ((c = *sp++) == '\\') {
if (sp == ep) {
/*
* The EOS was encountered when expecting the reverse solidus to
* be followed by the character it is escaping. Set an error code
* and return the number of characters consumed up to this point.
*/
b->error = _URE_UNEXPECTED_EOS;
return sp - sym;
}
c = *sp++;
switch (c) {
case 'p':
case 'P':
symp->type = (c == 'p') ? _URE_CCLASS : _URE_NCCLASS;
sp += _ure_prop_list(sp, ep - sp, &symp->props, b);
break;
case 'a':
symp->type = _URE_CHAR;
symp->sym.chr = 0x07;
break;
case 'b':
symp->type = _URE_CHAR;
symp->sym.chr = 0x08;
break;
case 'f':
symp->type = _URE_CHAR;
symp->sym.chr = 0x0c;
break;
case 'n':
symp->type = _URE_CHAR;
symp->sym.chr = 0x0a;
break;
case 'r':
symp->type = _URE_CHAR;
symp->sym.chr = 0x0d;
break;
case 't':
symp->type = _URE_CHAR;
symp->sym.chr = 0x09;
break;
case 'v':
symp->type = _URE_CHAR;
symp->sym.chr = 0x0b;
break;
case 'x':
case 'X':
case 'u':
case 'U':
/*
* Collect between 1 and 4 digits representing a UCS2 code. Fall
* through to the next case.
*/
if (sp < ep &&
((*sp >= '0' && *sp <= '9') ||
(*sp >= 'A' && *sp <= 'F') ||
(*sp >= 'a' && *sp <= 'f')))
sp += _ure_hex(sp, ep - sp, &c);
/* FALLTHROUGH */
default:
/*
* Simply add an escaped character here.
*/
symp->type = _URE_CHAR;
symp->sym.chr = c;
}
} else if (c == '^' || c == '$')
/*
* Handle the BOL and EOL anchors. This actually consists simply of
* setting a flag that indicates that the user supplied anchor match
* function should be called. This needs to be done instead of simply
* matching line/paragraph separators because beginning-of-text and
* end-of-text tests are needed as well.
*/
symp->type = (c == '^') ? _URE_BOL_ANCHOR : _URE_EOL_ANCHOR;
else if (c == '[')
/*
* Construct a character class.
*/
sp += _ure_cclass(sp, ep - sp, symp, b);
else if (c == '.')
symp->type = _URE_ANY_CHAR;
else {
symp->type = _URE_CHAR;
symp->sym.chr = c;
}
/*
* If the symbol type happens to be a character and is a high surrogate,
* then probe forward to see if it is followed by a low surrogate that
* needs to be added.
*/
if (sp < ep && symp->type == _URE_CHAR &&
0xd800 <= symp->sym.chr && symp->sym.chr <= 0xdbff) {
if (0xdc00 <= *sp && *sp <= 0xdfff) {
symp->sym.chr = 0x10000 + (((symp->sym.chr & 0x03ff) << 10) |
(*sp & 0x03ff));
sp++;
} else if (*sp == '\\' && (*(sp + 1) == 'x' || *(sp + 1) == 'X' ||
*(sp + 1) == 'u' || *(sp + 1) == 'U')) {
sp += _ure_probe_ls(sp + 2, ep - (sp + 2), &c);
if (0xdc00 <= c && c <= 0xdfff) {
/*
* Take into account the \[xu] in front of the hex code.
*/
sp += 2;
symp->sym.chr = 0x10000 + (((symp->sym.chr & 0x03ff) << 10) |
(c & 0x03ff));
}
}
}
/*
* Last, make sure any _URE_CHAR type symbols are changed to lower case if
* the `casefold' flag is set.
*/
if ((b->flags & _URE_DFA_CASEFOLD) && symp->type == _URE_CHAR)
symp->sym.chr = _ure_tolower(symp->sym.chr);
/*
* If the symbol constructed is anything other than one of the anchors,
* make sure the _URE_DFA_BLANKLINE flag is removed.
*/
if (symp->type != _URE_BOL_ANCHOR && symp->type != _URE_EOL_ANCHOR)
b->flags &= ~_URE_DFA_BLANKLINE;
/*
* Return the number of characters consumed.
*/
return sp - sym;
}
static int
_ure_sym_neq(_ure_symtab_t *a, _ure_symtab_t *b)
{
if (a->type != b->type || a->mods != b->mods || a->props != b->props)
return 1;
if (a->type == _URE_CCLASS || a->type == _URE_NCCLASS) {
if (a->sym.ccl.ranges_used != b->sym.ccl.ranges_used)
return 1;
if (a->sym.ccl.ranges_used > 0 &&
memcmp((char *) a->sym.ccl.ranges, (char *) b->sym.ccl.ranges,
sizeof(_ure_range_t) * a->sym.ccl.ranges_used) != 0)
return 1;
} else if (a->type == _URE_CHAR && a->sym.chr != b->sym.chr)
return 1;
return 0;
}
/*
* Construct a symbol, but only keep unique symbols.
*/
static ucs2_t
_ure_make_symbol(ucs2_t *sym, unsigned long limit, unsigned long *consumed,
_ure_buffer_t *b)
{
ucs2_t i;
_ure_symtab_t *sp, symbol;
/*
* Build the next symbol so we can test to see if it is already in the
* symbol table.
*/
(void) memset((char *) &symbol, '\0', sizeof(_ure_symtab_t));
*consumed = _ure_compile_symbol(sym, limit, &symbol, b);
/*
* Check to see if the symbol exists.
*/
for (i = 0, sp = b->symtab;
i < b->symtab_used && _ure_sym_neq(&symbol, sp); i++, sp++) ;
if (i < b->symtab_used) {
/*
* Free up any ranges used for the symbol.
*/
if ((symbol.type == _URE_CCLASS || symbol.type == _URE_NCCLASS) &&
symbol.sym.ccl.ranges_size > 0)
free((char *) symbol.sym.ccl.ranges);
return b->symtab[i].id;
}
/*
* Need to add the new symbol.
*/
if (b->symtab_used == b->symtab_size) {
if (b->symtab_size == 0)
b->symtab = (_ure_symtab_t *) malloc(sizeof(_ure_symtab_t) << 3);
else
b->symtab = (_ure_symtab_t *)
realloc((char *) b->symtab,
sizeof(_ure_symtab_t) * (b->symtab_size + 8));
sp = b->symtab + b->symtab_size;
(void) memset((char *) sp, '\0', sizeof(_ure_symtab_t) << 3);
b->symtab_size += 8;
}
symbol.id = b->symtab_used++;
(void) AC_MEMCPY((char *) &b->symtab[symbol.id], (char *) &symbol,
sizeof(_ure_symtab_t));
return symbol.id;
}
/*************************************************************************
*
* End symbol parse functions.
*
*************************************************************************/
static ucs2_t
_ure_make_expr(ucs2_t type, ucs2_t lhs, ucs2_t rhs, _ure_buffer_t *b)
{
ucs2_t i;
if (b == 0)
return _URE_NOOP;
/*
* Determine if the expression already exists or not.
*/
for (i = 0; i < b->expr_used; i++) {
if (b->expr[i].type == type && b->expr[i].lhs == lhs &&
b->expr[i].rhs == rhs)
break;
}
if (i < b->expr_used)
return i;
/*
* Need to add a new expression.
*/
if (b->expr_used == b->expr_size) {
if (b->expr_size == 0)
b->expr = (_ure_elt_t *) malloc(sizeof(_ure_elt_t) << 3);
else
b->expr = (_ure_elt_t *)
realloc((char *) b->expr,
sizeof(_ure_elt_t) * (b->expr_size + 8));
b->expr_size += 8;
}
b->expr[b->expr_used].onstack = 0;
b->expr[b->expr_used].type = type;
b->expr[b->expr_used].lhs = lhs;
b->expr[b->expr_used].rhs = rhs;
return b->expr_used++;
}
static unsigned char spmap[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
#define _ure_isspecial(cc) ((cc) > 0x20 && (cc) < 0x7f && \
(spmap[(cc) >> 3] & (1 << ((cc) & 7))))
/*
* Convert the regular expression into an NFA in a form that will be easy to
* reduce to a DFA. The starting state for the reduction will be returned.
*/
static ucs2_t
_ure_re2nfa(ucs2_t *re, unsigned long relen, _ure_buffer_t *b)
{
ucs2_t c, state, top, sym, *sp, *ep;
unsigned long used;
state = _URE_NOOP;
sp = re;
ep = sp + relen;
while (b->error == _URE_OK && sp < ep) {
c = *sp++;
switch (c) {
case '(':
_ure_push(_URE_PAREN, b);
break;
case ')':
/*
* Check for the case of too many close parentheses.
*/
if (_ure_peek(b) == _URE_NOOP) {
b->error = _URE_UNBALANCED_GROUP;
break;
}
while ((top = _ure_peek(b)) == _URE_AND || top == _URE_OR)
/*
* Make an expression with the AND or OR operator and its right
* hand side.
*/
state = _ure_make_expr(_ure_pop(b), _ure_pop(b), state, b);
/*
* Remove the _URE_PAREN off the stack.
*/
(void) _ure_pop(b);
break;
case '*':
state = _ure_make_expr(_URE_STAR, state, _URE_NOOP, b);
break;
case '+':
state = _ure_make_expr(_URE_PLUS, state, _URE_NOOP, b);
break;
case '?':
state = _ure_make_expr(_URE_QUEST, state, _URE_NOOP, b);
break;
case '|':
while ((top = _ure_peek(b)) == _URE_AND || top == _URE_OR)
/*
* Make an expression with the AND or OR operator and its right
* hand side.
*/
state = _ure_make_expr(_ure_pop(b), _ure_pop(b), state, b);
_ure_push(state, b);
_ure_push(_URE_OR, b);
break;
default:
sp--;
sym = _ure_make_symbol(sp, ep - sp, &used, b);
sp += used;
state = _ure_make_expr(_URE_SYMBOL, sym, _URE_NOOP, b);
break;
}
if (c != '(' && c != '|' && sp < ep &&
(!_ure_isspecial(*sp) || *sp == '(')) {
_ure_push(state, b);
_ure_push(_URE_AND, b);
}
}
while ((top = _ure_peek(b)) == _URE_AND || top == _URE_OR)
/*
* Make an expression with the AND or OR operator and its right
* hand side.
*/
state = _ure_make_expr(_ure_pop(b), _ure_pop(b), state, b);
if (b->stack.slist_used > 0)
b->error = _URE_UNBALANCED_GROUP;
return (b->error == _URE_OK) ? state : _URE_NOOP;
}
static void
_ure_add_symstate(ucs2_t sym, ucs2_t state, _ure_buffer_t *b)
{
ucs2_t i, *stp;
_ure_symtab_t *sp;
/*
* Locate the symbol in the symbol table so the state can be added.
* If the symbol doesn't exist, then a real problem exists.
*/
for (i = 0, sp = b->symtab; i < b->symtab_used && sym != sp->id;
i++, sp++) ;
/*
* Now find out if the state exists in the symbol's state list.
*/
for (i = 0, stp = sp->states.slist;
i < sp->states.slist_used && state > *stp; i++, stp++) ;
if (i == sp->states.slist_used || state < *stp) {
/*
* Need to add the state in order.
*/
if (sp->states.slist_used == sp->states.slist_size) {
if (sp->states.slist_size == 0)
sp->states.slist = (ucs2_t *) malloc(sizeof(ucs2_t) << 3);
else
sp->states.slist = (ucs2_t *)
realloc((char *) sp->states.slist,
sizeof(ucs2_t) * (sp->states.slist_size + 8));
sp->states.slist_size += 8;
}
if (i < sp->states.slist_used)
(void) _ure_memmove((char *) (sp->states.slist + i + 1),
(char *) (sp->states.slist + i),
sizeof(ucs2_t) * (sp->states.slist_used - i));
sp->states.slist[i] = state;
sp->states.slist_used++;
}
}
static ucs2_t
_ure_add_state(ucs2_t nstates, ucs2_t *states, _ure_buffer_t *b)
{
ucs2_t i;
_ure_state_t *sp;
for (i = 0, sp = b->states.states; i < b->states.states_used; i++, sp++) {
if (sp->st.slist_used == nstates &&
memcmp((char *) states, (char *) sp->st.slist,
sizeof(ucs2_t) * nstates) == 0)
break;
}
if (i == b->states.states_used) {
/*
* Need to add a new DFA state (set of NFA states).
*/
if (b->states.states_used == b->states.states_size) {
if (b->states.states_size == 0)
b->states.states = (_ure_state_t *)
malloc(sizeof(_ure_state_t) << 3);
else
b->states.states = (_ure_state_t *)
realloc((char *) b->states.states,
sizeof(_ure_state_t) * (b->states.states_size + 8));
sp = b->states.states + b->states.states_size;
(void) memset((char *) sp, '\0', sizeof(_ure_state_t) << 3);
b->states.states_size += 8;
}
sp = b->states.states + b->states.states_used++;
sp->id = i;
if (sp->st.slist_used + nstates > sp->st.slist_size) {
if (sp->st.slist_size == 0)
sp->st.slist = (ucs2_t *)
malloc(sizeof(ucs2_t) * (sp->st.slist_used + nstates));
else
sp->st.slist = (ucs2_t *)
realloc((char *) sp->st.slist,
sizeof(ucs2_t) * (sp->st.slist_used + nstates));
sp->st.slist_size = sp->st.slist_used + nstates;
}
sp->st.slist_used = nstates;
(void) AC_MEMCPY((char *) sp->st.slist, (char *) states,
sizeof(ucs2_t) * nstates);
}
/*
* Return the ID of the DFA state representing a group of NFA states.
*/
return i;
}
static void
_ure_reduce(ucs2_t start, _ure_buffer_t *b)
{
ucs2_t i, j, state, eval, syms, rhs;
ucs2_t s1, s2, ns1, ns2;
_ure_state_t *sp;
_ure_symtab_t *smp;
b->reducing = 1;
/*
* Add the starting state for the reduction.
*/
_ure_add_state(1, &start, b);
/*
* Process each set of NFA states that get created.
*/
for (i = 0; i < b->states.states_used; i++) {
sp = b->states.states + i;
/*
* Push the current states on the stack.
*/
for (j = 0; j < sp->st.slist_used; j++)
_ure_push(sp->st.slist[j], b);
/*
* Reduce the NFA states.
*/
for (j = sp->accepting = syms = 0; j < b->stack.slist_used; j++) {
state = b->stack.slist[j];
eval = 1;
/*
* This inner loop is the iterative equivalent of recursively
* reducing subexpressions generated as a result of a reduction.
*/
while (eval) {
switch (b->expr[state].type) {
case _URE_SYMBOL:
ns1 = _ure_make_expr(_URE_ONE, _URE_NOOP, _URE_NOOP, b);
_ure_add_symstate(b->expr[state].lhs, ns1, b);
syms++;
eval = 0;
break;
case _URE_ONE:
sp->accepting = 1;
eval = 0;
break;
case _URE_QUEST:
s1 = b->expr[state].lhs;
ns1 = _ure_make_expr(_URE_ONE, _URE_NOOP, _URE_NOOP, b);
state = _ure_make_expr(_URE_OR, ns1, s1, b);
break;
case _URE_PLUS:
s1 = b->expr[state].lhs;
ns1 = _ure_make_expr(_URE_STAR, s1, _URE_NOOP, b);
state = _ure_make_expr(_URE_AND, s1, ns1, b);
break;
case _URE_STAR:
s1 = b->expr[state].lhs;
ns1 = _ure_make_expr(_URE_ONE, _URE_NOOP, _URE_NOOP, b);
ns2 = _ure_make_expr(_URE_PLUS, s1, _URE_NOOP, b);
state = _ure_make_expr(_URE_OR, ns1, ns2, b);
break;
case _URE_OR:
s1 = b->expr[state].lhs;
s2 = b->expr[state].rhs;
_ure_push(s1, b);
_ure_push(s2, b);
eval = 0;
break;
case _URE_AND:
s1 = b->expr[state].lhs;
s2 = b->expr[state].rhs;
switch (b->expr[s1].type) {
case _URE_SYMBOL:
_ure_add_symstate(b->expr[s1].lhs, s2, b);
syms++;
eval = 0;
break;
case _URE_ONE:
state = s2;
break;
case _URE_QUEST:
ns1 = b->expr[s1].lhs;
ns2 = _ure_make_expr(_URE_AND, ns1, s2, b);
state = _ure_make_expr(_URE_OR, s2, ns2, b);
break;
case _URE_PLUS:
ns1 = b->expr[s1].lhs;
ns2 = _ure_make_expr(_URE_OR, s2, state, b);
state = _ure_make_expr(_URE_AND, ns1, ns2, b);
break;
case _URE_STAR:
ns1 = b->expr[s1].lhs;
ns2 = _ure_make_expr(_URE_AND, ns1, state, b);
state = _ure_make_expr(_URE_OR, s2, ns2, b);
break;
case _URE_OR:
ns1 = b->expr[s1].lhs;
ns2 = b->expr[s1].rhs;
ns1 = _ure_make_expr(_URE_AND, ns1, s2, b);
ns2 = _ure_make_expr(_URE_AND, ns2, s2, b);
state = _ure_make_expr(_URE_OR, ns1, ns2, b);
break;
case _URE_AND:
ns1 = b->expr[s1].lhs;
ns2 = b->expr[s1].rhs;
ns2 = _ure_make_expr(_URE_AND, ns2, s2, b);
state = _ure_make_expr(_URE_AND, ns1, ns2, b);
break;
}
}
}
}
/*
* Clear the state stack.
*/
while (_ure_pop(b) != _URE_NOOP) ;
/*
* Reset the state pointer because the reduction may have moved it
* during a reallocation.
*/
sp = b->states.states + i;
/*
* Generate the DFA states for the symbols collected during the
* current reduction.
*/
if (sp->trans_used + syms > sp->trans_size) {
if (sp->trans_size == 0)
sp->trans = (_ure_elt_t *)
malloc(sizeof(_ure_elt_t) * (sp->trans_used + syms));
else
sp->trans = (_ure_elt_t *)
realloc((char *) sp->trans,
sizeof(_ure_elt_t) * (sp->trans_used + syms));
sp->trans_size = sp->trans_used + syms;
}
/*
* Go through the symbol table and generate the DFA state transitions
* for each symbol that has collected NFA states.
*/
for (j = syms = 0, smp = b->symtab; j < b->symtab_used; j++, smp++) {
sp = b->states.states + i;
if (smp->states.slist_used > 0) {
sp->trans[syms].lhs = smp->id;
rhs = _ure_add_state(smp->states.slist_used,
smp->states.slist, b);
/*
* Reset the state pointer in case the reallocation moves it
* in memory.
*/
sp = b->states.states + i;
sp->trans[syms].rhs = rhs;
smp->states.slist_used = 0;
syms++;
}
}
/*
* Set the number of transitions actually used.
*/
sp->trans_used = syms;
}
b->reducing = 0;
}
static void
_ure_add_equiv(ucs2_t l, ucs2_t r, _ure_buffer_t *b)
{
ucs2_t tmp;
l = b->states.states[l].id;
r = b->states.states[r].id;
if (l == r)
return;
if (l > r) {
tmp = l;
l = r;
r = tmp;
}
/*
* Check to see if the equivalence pair already exists.
*/
for (tmp = 0; tmp < b->equiv_used &&
(b->equiv[tmp].l != l || b->equiv[tmp].r != r);
tmp++) ;
if (tmp < b->equiv_used)
return;
if (b->equiv_used == b->equiv_size) {
if (b->equiv_size == 0)
b->equiv = (_ure_equiv_t *) malloc(sizeof(_ure_equiv_t) << 3);
else
b->equiv = (_ure_equiv_t *) realloc((char *) b->equiv,
sizeof(_ure_equiv_t) *
(b->equiv_size + 8));
b->equiv_size += 8;
}
b->equiv[b->equiv_used].l = l;
b->equiv[b->equiv_used].r = r;
b->equiv_used++;
}
/*
* Merge the DFA states that are equivalent.
*/
static void
_ure_merge_equiv(_ure_buffer_t *b)
{
ucs2_t i, j, k, eq, done;
_ure_state_t *sp1, *sp2, *ls, *rs;
for (i = 0; i < b->states.states_used; i++) {
sp1 = b->states.states + i;
if (sp1->id != i)
continue;
for (j = 0; j < i; j++) {
sp2 = b->states.states + j;
if (sp2->id != j)
continue;
b->equiv_used = 0;
_ure_add_equiv(i, j, b);
for (eq = 0, done = 0; eq < b->equiv_used; eq++) {
ls = b->states.states + b->equiv[eq].l;
rs = b->states.states + b->equiv[eq].r;
if (ls->accepting != rs->accepting ||
ls->trans_used != rs->trans_used) {
done = 1;
break;
}
for (k = 0; k < ls->trans_used &&
ls->trans[k].lhs == rs->trans[k].lhs; k++) ;
if (k < ls->trans_used) {
done = 1;
break;
}
for (k = 0; k < ls->trans_used; k++)
_ure_add_equiv(ls->trans[k].rhs, rs->trans[k].rhs, b);
}
if (done == 0)
break;
}
for (eq = 0; j < i && eq < b->equiv_used; eq++)
b->states.states[b->equiv[eq].r].id =
b->states.states[b->equiv[eq].l].id;
}
/*
* Renumber the states appropriately.
*/
for (i = eq = 0, sp1 = b->states.states; i < b->states.states_used;
sp1++, i++)
sp1->id = (sp1->id == i) ? eq++ : b->states.states[sp1->id].id;
}
/*************************************************************************
*
* API.
*
*************************************************************************/
ure_buffer_t
ure_buffer_create(void)
{
ure_buffer_t b;
b = (ure_buffer_t) calloc(1, sizeof(_ure_buffer_t));
return b;
}
void
ure_buffer_free(ure_buffer_t buf)
{
unsigned long i;
if (buf == 0)
return;
if (buf->stack.slist_size > 0)
free((char *) buf->stack.slist);
if (buf->expr_size > 0)
free((char *) buf->expr);
for (i = 0; i < buf->symtab_size; i++) {
if (buf->symtab[i].states.slist_size > 0)
free((char *) buf->symtab[i].states.slist);
}
if (buf->symtab_size > 0)
free((char *) buf->symtab);
for (i = 0; i < buf->states.states_size; i++) {
if (buf->states.states[i].trans_size > 0)
free((char *) buf->states.states[i].trans);
if (buf->states.states[i].st.slist_size > 0)
free((char *) buf->states.states[i].st.slist);
}
if (buf->states.states_size > 0)
free((char *) buf->states.states);
if (buf->equiv_size > 0)
free((char *) buf->equiv);
free((char *) buf);
}
ure_dfa_t
ure_compile(ucs2_t *re, unsigned long relen, int casefold, ure_buffer_t buf)
{
ucs2_t i, j, state;
_ure_state_t *sp;
_ure_dstate_t *dsp;
_ure_trans_t *tp;
ure_dfa_t dfa;
if (re == 0 || *re == 0 || relen == 0 || buf == 0)
return 0;
/*
* Reset the various fields of the compilation buffer. Default the flags
* to indicate the presense of the "^$" pattern. If any other pattern
* occurs, then this flag will be removed. This is done to catch this
* special pattern and handle it specially when matching.
*/
buf->flags = _URE_DFA_BLANKLINE | ((casefold) ? _URE_DFA_CASEFOLD : 0);
buf->reducing = 0;
buf->stack.slist_used = 0;
buf->expr_used = 0;
for (i = 0; i < buf->symtab_used; i++)
buf->symtab[i].states.slist_used = 0;
buf->symtab_used = 0;
for (i = 0; i < buf->states.states_used; i++) {
buf->states.states[i].st.slist_used = 0;
buf->states.states[i].trans_used = 0;
}
buf->states.states_used = 0;
/*
* Construct the NFA. If this stage returns a 0, then an error occured or
* an empty expression was passed.
*/
if ((state = _ure_re2nfa(re, relen, buf)) == _URE_NOOP)
return 0;
/*
* Do the expression reduction to get the initial DFA.
*/
_ure_reduce(state, buf);
/*
* Merge all the equivalent DFA states.
*/
_ure_merge_equiv(buf);
/*
* Construct the minimal DFA.
*/
dfa = (ure_dfa_t) malloc(sizeof(_ure_dfa_t));
(void) memset((char *) dfa, '\0', sizeof(_ure_dfa_t));
dfa->flags = buf->flags & (_URE_DFA_CASEFOLD|_URE_DFA_BLANKLINE);
/*
* Free up the NFA state groups and transfer the symbols from the buffer
* to the DFA.
*/
for (i = 0; i < buf->symtab_size; i++) {
if (buf->symtab[i].states.slist_size > 0)
free((char *) buf->symtab[i].states.slist);
}
dfa->syms = buf->symtab;
dfa->nsyms = buf->symtab_used;
buf->symtab_used = buf->symtab_size = 0;
/*
* Collect the total number of states and transitions needed for the DFA.
*/
for (i = state = 0, sp = buf->states.states; i < buf->states.states_used;
i++, sp++) {
if (sp->id == state) {
dfa->nstates++;
dfa->ntrans += sp->trans_used;
state++;
}
}
/*
* Allocate enough space for the states and transitions.
*/
dfa->states = (_ure_dstate_t *) malloc(sizeof(_ure_dstate_t) *
dfa->nstates);
dfa->trans = (_ure_trans_t *) malloc(sizeof(_ure_trans_t) * dfa->ntrans);
/*
* Actually transfer the DFA states from the buffer.
*/
dsp = dfa->states;
tp = dfa->trans;
for (i = state = 0, sp = buf->states.states; i < buf->states.states_used;
i++, sp++) {
if (sp->id == state) {
dsp->trans = tp;
dsp->ntrans = sp->trans_used;
dsp->accepting = sp->accepting;
/*
* Add the transitions for the state.
*/
for (j = 0; j < dsp->ntrans; j++, tp++) {
tp->symbol = sp->trans[j].lhs;
tp->next_state = buf->states.states[sp->trans[j].rhs].id;
}
dsp++;
state++;
}
}
return dfa;
}
void
ure_dfa_free(ure_dfa_t dfa)
{
ucs2_t i;
if (dfa == 0)
return;
for (i = 0; i < dfa->nsyms; i++) {
if ((dfa->syms[i].type == _URE_CCLASS ||
dfa->syms[i].type == _URE_NCCLASS) &&
dfa->syms[i].sym.ccl.ranges_size > 0)
free((char *) dfa->syms[i].sym.ccl.ranges);
}
if (dfa->nsyms > 0)
free((char *) dfa->syms);
if (dfa->nstates > 0)
free((char *) dfa->states);
if (dfa->ntrans > 0)
free((char *) dfa->trans);
free((char *) dfa);
}
void
ure_write_dfa(ure_dfa_t dfa, FILE *out)
{
ucs2_t i, j, k, h, l;
_ure_dstate_t *sp;
_ure_symtab_t *sym;
_ure_range_t *rp;
if (dfa == 0 || out == 0)
return;
/*
* Write all the different character classes.
*/
for (i = 0, sym = dfa->syms; i < dfa->nsyms; i++, sym++) {
if (sym->type == _URE_CCLASS || sym->type == _URE_NCCLASS) {
fprintf(out, "C%hd = ", sym->id);
if (sym->sym.ccl.ranges_used > 0) {
putc('[', out);
if (sym->type == _URE_NCCLASS)
putc('^', out);
}
if (sym->props != 0) {
if (sym->type == _URE_NCCLASS)
fprintf(out, "\\P");
else
fprintf(out, "\\p");
for (k = h = 0; k < 32; k++) {
if (sym->props & (1 << k)) {
if (h != 0)
putc(',', out);
fprintf(out, "%d", k + 1);
h = 1;
}
}
}
/*
* Dump the ranges.
*/
for (k = 0, rp = sym->sym.ccl.ranges;
k < sym->sym.ccl.ranges_used; k++, rp++) {
/*
* Check for UTF16 characters.
*/
if (0x10000 <= rp->min_code &&
rp->min_code <= 0x10ffff) {
h = (ucs2_t) (((rp->min_code - 0x10000) >> 10) + 0xd800);
l = (ucs2_t) (((rp->min_code - 0x10000) & 1023) + 0xdc00);
fprintf(out, "\\x%04hX\\x%04hX", h, l);
} else
fprintf(out, "\\x%04lX", rp->min_code & 0xffff);
if (rp->max_code != rp->min_code) {
putc('-', out);
if (rp->max_code >= 0x10000 &&
rp->max_code <= 0x10ffff) {
h = (ucs2_t) (((rp->max_code - 0x10000) >> 10) + 0xd800);
l = (ucs2_t) (((rp->max_code - 0x10000) & 1023) + 0xdc00);
fprintf(out, "\\x%04hX\\x%04hX", h, l);
} else
fprintf(out, "\\x%04lX", rp->max_code & 0xffff);
}
}
if (sym->sym.ccl.ranges_used > 0)
putc(']', out);
putc('\n', out);
}
}
for (i = 0, sp = dfa->states; i < dfa->nstates; i++, sp++) {
fprintf(out, "S%hd = ", i);
if (sp->accepting) {
fprintf(out, "1 ");
if (sp->ntrans)
fprintf(out, "| ");
}
for (j = 0; j < sp->ntrans; j++) {
if (j > 0)
fprintf(out, "| ");
sym = dfa->syms + sp->trans[j].symbol;
switch (sym->type) {
case _URE_CHAR:
if (0x10000 <= sym->sym.chr && sym->sym.chr <= 0x10ffff) {
/*
* Take care of UTF16 characters.
*/
h = (ucs2_t) (((sym->sym.chr - 0x10000) >> 10) + 0xd800);
l = (ucs2_t) (((sym->sym.chr - 0x10000) & 1023) + 0xdc00);
fprintf(out, "\\x%04hX\\x%04hX ", h, l);
} else
fprintf(out, "\\x%04lX ", sym->sym.chr & 0xffff);
break;
case _URE_ANY_CHAR:
fprintf(out, "<any> ");
break;
case _URE_BOL_ANCHOR:
fprintf(out, "<bol-anchor> ");
break;
case _URE_EOL_ANCHOR:
fprintf(out, "<eol-anchor> ");
break;
case _URE_CCLASS:
case _URE_NCCLASS:
fprintf(out, "[C%hd] ", sym->id);
break;
}
fprintf(out, "S%hd", sp->trans[j].next_state);
if (j + 1 < sp->ntrans)
putc(' ', out);
}
putc('\n', out);
}
}
#define _ure_issep(cc) ((cc) == '\n' || (cc) == '\r' || (cc) == 0x2028 ||\
(cc) == 0x2029)
int
ure_exec(ure_dfa_t dfa, int flags, ucs2_t *text, unsigned long textlen,
unsigned long *match_start, unsigned long *match_end)
{
int i, j, matched, found, skip;
unsigned long ms, me;
ucs4_t c;
ucs2_t *sp, *ep, *lp;
_ure_dstate_t *stp;
_ure_symtab_t *sym;
_ure_range_t *rp;
if (dfa == 0 || text == 0)
return 0;
/*
* Handle the special case of an empty string matching the "^$" pattern.
*/
if (textlen == 0 && (dfa->flags & _URE_DFA_BLANKLINE)) {
*match_start = *match_end = 0;
return 1;
}
sp = text;
ep = sp + textlen;
ms = me = ~0;
stp = dfa->states;
for (found = skip = 0; found == 0 && sp < ep; ) {
lp = sp;
c = *sp++;
/*
* Check to see if this is a high surrogate that should be
* combined with a following low surrogate.
*/
if (sp < ep && 0xd800 <= c && c <= 0xdbff &&
0xdc00 <= *sp && *sp <= 0xdfff)
c = 0x10000 + (((c & 0x03ff) << 10) | (*sp++ & 0x03ff));
/*
* Determine if the character is non-spacing and should be skipped.
*/
if (_ure_matches_properties(_URE_NONSPACING, c) &&
(flags & URE_IGNORE_NONSPACING)) {
sp++;
continue;
}
if (dfa->flags & _URE_DFA_CASEFOLD)
c = _ure_tolower(c);
/*
* See if one of the transitions matches.
*/
for (i = 0, matched = 0; matched == 0 && i < stp->ntrans; i++) {
sym = dfa->syms + stp->trans[i].symbol;
switch (sym->type) {
case _URE_ANY_CHAR:
if ((flags & URE_DOT_MATCHES_SEPARATORS) ||
!_ure_issep(c))
matched = 1;
break;
case _URE_CHAR:
if (c == sym->sym.chr)
matched = 1;
break;
case _URE_BOL_ANCHOR:
if (lp == text) {
sp = lp;
matched = 1;
} else if (_ure_issep(c)) {
if (c == '\r' && sp < ep && *sp == '\n')
sp++;
lp = sp;
matched = 1;
}
break;
case _URE_EOL_ANCHOR:
if (_ure_issep(c)) {
/*
* Put the pointer back before the separator so the match
* end position will be correct. This case will also
* cause the `sp' pointer to be advanced over the current
* separator once the match end point has been recorded.
*/
sp = lp;
matched = 1;
}
break;
case _URE_CCLASS:
case _URE_NCCLASS:
if (sym->props != 0)
matched = _ure_matches_properties(sym->props, c);
for (j = 0, rp = sym->sym.ccl.ranges;
j < sym->sym.ccl.ranges_used; j++, rp++) {
if (rp->min_code <= c && c <= rp->max_code)
matched = 1;
}
if (sym->type == _URE_NCCLASS)
matched = !matched;
break;
}
if (matched) {
if (ms == ~0UL)
ms = lp - text;
else
me = sp - text;
stp = dfa->states + stp->trans[i].next_state;
/*
* If the match was an EOL anchor, adjust the pointer past the
* separator that caused the match. The correct match
* position has been recorded already.
*/
if (sym->type == _URE_EOL_ANCHOR) {
/*
* Skip the character that caused the match.
*/
sp++;
/*
* Handle the infamous CRLF situation.
*/
if (sp < ep && c == '\r' && *sp == '\n')
sp++;
}
}
}
if (matched == 0) {
if (stp->accepting == 0) {
/*
* If the last state was not accepting, then reset
* and start over.
*/
stp = dfa->states;
ms = me = ~0;
} else
/*
* The last state was accepting, so terminate the matching
* loop to avoid more work.
*/
found = 1;
} else if (sp == ep) {
if (!stp->accepting) {
/*
* This ugly hack is to make sure the end-of-line anchors
* match when the source text hits the end. This is only done
* if the last subexpression matches.
*/
for (i = 0; found == 0 && i < stp->ntrans; i++) {
sym = dfa->syms + stp->trans[i].symbol;
if (sym->type ==_URE_EOL_ANCHOR) {
stp = dfa->states + stp->trans[i].next_state;
if (stp->accepting) {
me = sp - text;
found = 1;
} else
break;
}
}
} else {
/*
* Make sure any conditions that match all the way to the end
* of the string match.
*/
found = 1;
me = sp - text;
}
}
}
if (found == 0)
ms = me = ~0;
*match_start = ms;
*match_end = me;
return (ms != ~0UL) ? 1 : 0;
}
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