mariadb/regex/regcomp.c
Dmitry Shulga 378091e434 Fixed bug#58026 - massive recursion and crash in regular expression
handling.

The problem was that parsing of nested regular expression involved
recursive calls. Such recursion didn't take into account the amount of
available stack space, which ended up leading to stack overflow crashes.

mysql-test/t/not_embedded_server.test:
  Added test for bug#58026.
regex/my_regex.h:
  added pointer to function as last argument of my_regex_init() for check
  enough memory in stack.
regex/regcomp.c:
  p_ere() was modified: added call to function for check enough memory
  in stack. Function for check available stack space specified by
  global variable my_regex_enough_mem_in_stack. This variable set to
  NULL for embedded mysqld and to a pointer to function
  check_enough_stack_size otherwise.
regex/reginit.c:
  my_regex_init was modified: pass a pointer to a function for check
  enough memory in stack space. Reset this pointer to NULL in my_regex_end.
sql/mysqld.cc:
  Added function check_enough_stack_size() for check enough memory in stack.
  Passed this function as second argument to my_regex_init. For embedded 
  mysqld passed NULL as second argument.
2011-02-04 10:47:46 +06:00

1682 lines
39 KiB
C

#include <my_global.h>
#include <m_string.h>
#include <m_ctype.h>
#ifdef __WIN__
#include <limits.h>
#endif
#include "my_regex.h"
#include "utils.h"
#include "regex2.h"
#include "cclass.h"
#include "cname.h"
/*
* parse structure, passed up and down to avoid global variables and
* other clumsinesses
*/
struct parse {
char *next; /* next character in RE */
char *end; /* end of string (-> NUL normally) */
int error; /* has an error been seen? */
sop *strip; /* malloced strip */
sopno ssize; /* malloced strip size (allocated) */
sopno slen; /* malloced strip length (used) */
int ncsalloc; /* number of csets allocated */
struct re_guts *g;
# define NPAREN 10 /* we need to remember () 1-9 for back refs */
sopno pbegin[NPAREN]; /* -> ( ([0] unused) */
sopno pend[NPAREN]; /* -> ) ([0] unused) */
CHARSET_INFO *charset; /* for ctype things */
};
/* Check if there is enough stack space for recursion. */
my_regex_stack_check_t my_regex_enough_mem_in_stack= NULL;
#include "regcomp.ih"
static char nuls[10]; /* place to point scanner in event of error */
struct cclass cclasses[CCLASS_LAST+1]= {
{ "alnum", "","", _MY_U | _MY_L | _MY_NMR},
{ "alpha", "","", _MY_U | _MY_L },
{ "blank", "","", _MY_B },
{ "cntrl", "","", _MY_CTR },
{ "digit", "","", _MY_NMR },
{ "graph", "","", _MY_PNT | _MY_U | _MY_L | _MY_NMR},
{ "lower", "","", _MY_L },
{ "print", "","", _MY_PNT | _MY_U | _MY_L | _MY_NMR | _MY_B },
{ "punct", "","", _MY_PNT },
{ "space", "","", _MY_SPC },
{ "upper", "","", _MY_U },
{ "xdigit", "","", _MY_X },
{ NULL,NULL,NULL, 0 }
};
/*
* macros for use with parse structure
* BEWARE: these know that the parse structure is named `p' !!!
*/
#define PEEK() (*p->next)
#define PEEK2() (*(p->next+1))
#define MORE() (p->next < p->end)
#define MORE2() (p->next+1 < p->end)
#define SEE(c) (MORE() && PEEK() == (c))
#define SEETWO(a, b) (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
#define EAT(c) ((SEE(c)) ? (NEXT(), 1) : 0)
#define EATTWO(a, b) ((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
#define NEXT() (p->next++)
#define NEXT2() (p->next += 2)
#define NEXTn(n) (p->next += (n))
#define GETNEXT() (*p->next++)
#define SETERROR(e) seterr(p, (e))
#define REQUIRE(co, e) ((co) || SETERROR(e))
#define MUSTSEE(c, e) (REQUIRE(MORE() && PEEK() == (c), e))
#define MUSTEAT(c, e) (REQUIRE(MORE() && GETNEXT() == (c), e))
#define MUSTNOTSEE(c, e) (REQUIRE(!MORE() || PEEK() != (c), e))
#define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd))
#define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
#define AHEAD(pos) dofwd(p, pos, HERE()-(pos))
#define ASTERN(sop, pos) EMIT(sop, HERE()-pos)
#define HERE() (p->slen)
#define THERE() (p->slen - 1)
#define THERETHERE() (p->slen - 2)
#define DROP(n) (p->slen -= (n))
#ifndef NDEBUG
static int never = 0; /* for use in asserts; shuts lint up */
#else
#define never 0 /* some <assert.h>s have bugs too */
#endif
/*
- regcomp - interface for parser and compilation
= extern int regcomp(regex_t *, const char *, int);
= #define REG_BASIC 0000
= #define REG_EXTENDED 0001
= #define REG_ICASE 0002
= #define REG_NOSUB 0004
= #define REG_NEWLINE 0010
= #define REG_NOSPEC 0020
= #define REG_PEND 0040
= #define REG_DUMP 0200
*/
int /* 0 success, otherwise REG_something */
my_regcomp(preg, pattern, cflags, charset)
my_regex_t *preg;
const char *pattern;
int cflags;
CHARSET_INFO *charset;
{
struct parse pa;
register struct re_guts *g;
register struct parse *p = &pa;
register int i;
register size_t len;
#ifdef REDEBUG
# define GOODFLAGS(f) (f)
#else
# define GOODFLAGS(f) ((f)&~REG_DUMP)
#endif
my_regex_init(charset, NULL); /* Init cclass if neaded */
preg->charset=charset;
cflags = GOODFLAGS(cflags);
if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
return(REG_INVARG);
if (cflags&REG_PEND) {
if (preg->re_endp < pattern)
return(REG_INVARG);
len = preg->re_endp - pattern;
} else
len = strlen((char *)pattern);
/* do the mallocs early so failure handling is easy */
g = (struct re_guts *)malloc(sizeof(struct re_guts) +
(NC-1)*sizeof(cat_t));
if (g == NULL)
return(REG_ESPACE);
p->ssize = (long) (len/(size_t)2*(size_t)3 + (size_t)1); /* ugh */
p->strip = (sop *)malloc(p->ssize * sizeof(sop));
p->slen = 0;
if (p->strip == NULL) {
free((char *)g);
return(REG_ESPACE);
}
/* set things up */
p->g = g;
p->next = (char *)pattern; /* convenience; we do not modify it */
p->end = p->next + len;
p->error = 0;
p->ncsalloc = 0;
p->charset = preg->charset;
for (i = 0; i < NPAREN; i++) {
p->pbegin[i] = 0;
p->pend[i] = 0;
}
g->csetsize = NC;
g->sets = NULL;
g->setbits = NULL;
g->ncsets = 0;
g->cflags = cflags;
g->iflags = 0;
g->nbol = 0;
g->neol = 0;
g->must = NULL;
g->mlen = 0;
g->nsub = 0;
g->ncategories = 1; /* category 0 is "everything else" */
g->categories = &g->catspace[-(CHAR_MIN)];
(void) memset((char *)g->catspace, 0, NC*sizeof(cat_t));
g->backrefs = 0;
/* do it */
EMIT(OEND, 0);
g->firststate = THERE();
if (cflags&REG_EXTENDED)
p_ere(p, OUT);
else if (cflags&REG_NOSPEC)
p_str(p);
else
p_bre(p, OUT, OUT);
EMIT(OEND, 0);
g->laststate = THERE();
/* tidy up loose ends and fill things in */
categorize(p, g);
stripsnug(p, g);
findmust(p, g);
g->nplus = pluscount(p, g);
g->magic = MAGIC2;
preg->re_nsub = g->nsub;
preg->re_g = g;
preg->re_magic = MAGIC1;
#ifndef REDEBUG
/* not debugging, so can't rely on the assert() in regexec() */
if (g->iflags&BAD)
SETERROR(REG_ASSERT);
#endif
/* win or lose, we're done */
if (p->error != 0) /* lose */
my_regfree(preg);
return(p->error);
}
/*
- p_ere - ERE parser top level, concatenation and alternation
== static void p_ere(register struct parse *p, int stop);
*/
static void
p_ere(p, stop)
register struct parse *p;
int stop; /* character this ERE should end at */
{
register char c;
register sopno UNINIT_VAR(prevback);
register sopno UNINIT_VAR(prevfwd);
register sopno conc;
register int first = 1; /* is this the first alternative? */
for (;;) {
/* do a bunch of concatenated expressions */
conc = HERE();
while (MORE() && (c = PEEK()) != '|' && c != stop)
{
if (my_regex_enough_mem_in_stack &&
my_regex_enough_mem_in_stack())
{
SETERROR(REG_ESPACE);
return;
}
p_ere_exp(p);
}
if(REQUIRE(HERE() != conc, REG_EMPTY)) {}/* require nonempty */
if (!EAT('|'))
break; /* NOTE BREAK OUT */
if (first) {
INSERT(OCH_, conc); /* offset is wrong */
prevfwd = conc;
prevback = conc;
first = 0;
}
ASTERN(OOR1, prevback);
prevback = THERE();
AHEAD(prevfwd); /* fix previous offset */
prevfwd = HERE();
EMIT(OOR2, 0); /* offset is very wrong */
}
if (!first) { /* tail-end fixups */
AHEAD(prevfwd);
ASTERN(O_CH, prevback);
}
assert(!MORE() || SEE(stop));
}
/*
- p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
== static void p_ere_exp(register struct parse *p);
*/
static void
p_ere_exp(p)
register struct parse *p;
{
register char c;
register sopno pos;
register int count;
register int count2;
register sopno subno;
int wascaret = 0;
assert(MORE()); /* caller should have ensured this */
c = GETNEXT();
pos = HERE();
switch (c) {
case '(':
if(REQUIRE(MORE(), REG_EPAREN)) {}
p->g->nsub++;
subno = (sopno) p->g->nsub;
if (subno < NPAREN)
p->pbegin[subno] = HERE();
EMIT(OLPAREN, subno);
if (!SEE(')'))
p_ere(p, ')');
if (subno < NPAREN) {
p->pend[subno] = HERE();
assert(p->pend[subno] != 0);
}
EMIT(ORPAREN, subno);
if(MUSTEAT(')', REG_EPAREN)) {}
break;
#ifndef POSIX_MISTAKE
case ')': /* happens only if no current unmatched ( */
/*
* You may ask, why the ifndef? Because I didn't notice
* this until slightly too late for 1003.2, and none of the
* other 1003.2 regular-expression reviewers noticed it at
* all. So an unmatched ) is legal POSIX, at least until
* we can get it fixed.
*/
SETERROR(REG_EPAREN);
break;
#endif
case '^':
EMIT(OBOL, 0);
p->g->iflags |= USEBOL;
p->g->nbol++;
wascaret = 1;
break;
case '$':
EMIT(OEOL, 0);
p->g->iflags |= USEEOL;
p->g->neol++;
break;
case '|':
SETERROR(REG_EMPTY);
break;
case '*':
case '+':
case '?':
SETERROR(REG_BADRPT);
break;
case '.':
if (p->g->cflags&REG_NEWLINE)
nonnewline(p);
else
EMIT(OANY, 0);
break;
case '[':
p_bracket(p);
break;
case '\\':
if(REQUIRE(MORE(), REG_EESCAPE)) {}
c = GETNEXT();
ordinary(p, c);
break;
case '{': /* okay as ordinary except if digit follows */
if(REQUIRE(!MORE() || !my_isdigit(p->charset,PEEK()), REG_BADRPT)) {}
/* FALLTHROUGH */
default:
ordinary(p, c);
break;
}
if (!MORE())
return;
c = PEEK();
/* we call { a repetition if followed by a digit */
if (!( c == '*' || c == '+' || c == '?' ||
(c == '{' && MORE2() &&
my_isdigit(p->charset,PEEK2())) ))
return; /* no repetition, we're done */
NEXT();
if(REQUIRE(!wascaret, REG_BADRPT)) {}
switch (c) {
case '*': /* implemented as +? */
/* this case does not require the (y|) trick, noKLUDGE */
INSERT(OPLUS_, pos);
ASTERN(O_PLUS, pos);
INSERT(OQUEST_, pos);
ASTERN(O_QUEST, pos);
break;
case '+':
INSERT(OPLUS_, pos);
ASTERN(O_PLUS, pos);
break;
case '?':
/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
INSERT(OCH_, pos); /* offset slightly wrong */
ASTERN(OOR1, pos); /* this one's right */
AHEAD(pos); /* fix the OCH_ */
EMIT(OOR2, 0); /* offset very wrong... */
AHEAD(THERE()); /* ...so fix it */
ASTERN(O_CH, THERETHERE());
break;
case '{':
count = p_count(p);
if (EAT(',')) {
if (my_isdigit(p->charset,PEEK())) {
count2 = p_count(p);
if(REQUIRE(count <= count2, REG_BADBR)) {}
} else /* single number with comma */
count2 = RE_INFINITY;
} else /* just a single number */
count2 = count;
repeat(p, pos, count, count2);
if (!EAT('}')) { /* error heuristics */
while (MORE() && PEEK() != '}')
NEXT();
if(REQUIRE(MORE(), REG_EBRACE)) {}
SETERROR(REG_BADBR);
}
break;
}
if (!MORE())
return;
c = PEEK();
if (!( c == '*' || c == '+' || c == '?' ||
(c == '{' && MORE2() &&
my_isdigit(p->charset,PEEK2())) ) )
return;
SETERROR(REG_BADRPT);
}
/*
- p_str - string (no metacharacters) "parser"
== static void p_str(register struct parse *p);
*/
static void
p_str(p)
register struct parse *p;
{
if(REQUIRE(MORE(), REG_EMPTY)) {}
while (MORE())
ordinary(p, GETNEXT());
}
/*
- p_bre - BRE parser top level, anchoring and concatenation
== static void p_bre(register struct parse *p, register int end1, \
== register int end2);
* Giving end1 as OUT essentially eliminates the end1/end2 check.
*
* This implementation is a bit of a kludge, in that a trailing $ is first
* taken as an ordinary character and then revised to be an anchor. The
* only undesirable side effect is that '$' gets included as a character
* category in such cases. This is fairly harmless; not worth fixing.
* The amount of lookahead needed to avoid this kludge is excessive.
*/
static void
p_bre(p, end1, end2)
register struct parse *p;
register int end1; /* first terminating character */
register int end2; /* second terminating character */
{
register sopno start = HERE();
register int first = 1; /* first subexpression? */
register int wasdollar = 0;
if (EAT('^')) {
EMIT(OBOL, 0);
p->g->iflags |= USEBOL;
p->g->nbol++;
}
while (MORE() && !SEETWO(end1, end2)) {
wasdollar = p_simp_re(p, first);
first = 0;
}
if (wasdollar) { /* oops, that was a trailing anchor */
DROP(1);
EMIT(OEOL, 0);
p->g->iflags |= USEEOL;
p->g->neol++;
}
if(REQUIRE(HERE() != start, REG_EMPTY)) {} /* require nonempty */
}
/*
- p_simp_re - parse a simple RE, an atom possibly followed by a repetition
== static int p_simp_re(register struct parse *p, int starordinary);
*/
static int /* was the simple RE an unbackslashed $? */
p_simp_re(p, starordinary)
register struct parse *p;
int starordinary; /* is a leading * an ordinary character? */
{
register int c;
register int count;
register int count2;
register sopno pos;
register int i;
register sopno subno;
# define BACKSL (1<<CHAR_BIT)
pos = HERE(); /* repetion op, if any, covers from here */
assert(MORE()); /* caller should have ensured this */
c = GETNEXT();
if (c == '\\') {
if(REQUIRE(MORE(), REG_EESCAPE)) {}
c = BACKSL | (unsigned char)GETNEXT();
}
switch (c) {
case '.':
if (p->g->cflags&REG_NEWLINE)
nonnewline(p);
else
EMIT(OANY, 0);
break;
case '[':
p_bracket(p);
break;
case BACKSL|'{':
SETERROR(REG_BADRPT);
break;
case BACKSL|'(':
p->g->nsub++;
subno = (sopno) p->g->nsub;
if (subno < NPAREN)
p->pbegin[subno] = HERE();
EMIT(OLPAREN, subno);
/* the MORE here is an error heuristic */
if (MORE() && !SEETWO('\\', ')'))
p_bre(p, '\\', ')');
if (subno < NPAREN) {
p->pend[subno] = HERE();
assert(p->pend[subno] != 0);
}
EMIT(ORPAREN, subno);
if(REQUIRE(EATTWO('\\', ')'), REG_EPAREN)) {}
break;
case BACKSL|')': /* should not get here -- must be user */
case BACKSL|'}':
SETERROR(REG_EPAREN);
break;
case BACKSL|'1':
case BACKSL|'2':
case BACKSL|'3':
case BACKSL|'4':
case BACKSL|'5':
case BACKSL|'6':
case BACKSL|'7':
case BACKSL|'8':
case BACKSL|'9':
i = (c&~BACKSL) - '0';
assert(i < NPAREN);
if (p->pend[i] != 0) {
assert((uint) i <= p->g->nsub);
EMIT(OBACK_, i);
assert(p->pbegin[i] != 0);
assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
assert(OP(p->strip[p->pend[i]]) == ORPAREN);
(void) dupl(p, p->pbegin[i]+1, p->pend[i]);
EMIT(O_BACK, i);
} else
SETERROR(REG_ESUBREG);
p->g->backrefs = 1;
break;
case '*':
if(REQUIRE(starordinary, REG_BADRPT)) {}
/* FALLTHROUGH */
default:
ordinary(p, c &~ BACKSL);
break;
}
if (EAT('*')) { /* implemented as +? */
/* this case does not require the (y|) trick, noKLUDGE */
INSERT(OPLUS_, pos);
ASTERN(O_PLUS, pos);
INSERT(OQUEST_, pos);
ASTERN(O_QUEST, pos);
} else if (EATTWO('\\', '{')) {
count = p_count(p);
if (EAT(',')) {
if (MORE() && my_isdigit(p->charset,PEEK())) {
count2 = p_count(p);
if(REQUIRE(count <= count2, REG_BADBR)) {}
} else /* single number with comma */
count2 = RE_INFINITY;
} else /* just a single number */
count2 = count;
repeat(p, pos, count, count2);
if (!EATTWO('\\', '}')) { /* error heuristics */
while (MORE() && !SEETWO('\\', '}'))
NEXT();
if(REQUIRE(MORE(), REG_EBRACE)) {}
SETERROR(REG_BADBR);
}
} else if (c == (unsigned char)'$') /* $ (but not \$) ends it */
return(1);
return(0);
}
/*
- p_count - parse a repetition count
== static int p_count(register struct parse *p);
*/
static int /* the value */
p_count(p)
register struct parse *p;
{
register int count = 0;
register int ndigits = 0;
while (MORE() && my_isdigit(p->charset,PEEK()) && count <= DUPMAX) {
count = count*10 + (GETNEXT() - '0');
ndigits++;
}
if(REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR)) {}
return(count);
}
/*
- p_bracket - parse a bracketed character list
== static void p_bracket(register struct parse *p);
*
* Note a significant property of this code: if the allocset() did SETERROR,
* no set operations are done.
*/
static void
p_bracket(p)
register struct parse *p;
{
register cset *cs = allocset(p);
register int invert = 0;
/* Dept of Truly Sickening Special-Case Kludges */
if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) {
EMIT(OBOW, 0);
NEXTn(6);
return;
}
if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) {
EMIT(OEOW, 0);
NEXTn(6);
return;
}
if (EAT('^'))
invert++; /* make note to invert set at end */
if (EAT(']'))
CHadd(cs, ']');
else if (EAT('-'))
CHadd(cs, '-');
while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
p_b_term(p, cs);
if (EAT('-'))
CHadd(cs, '-');
if(MUSTEAT(']', REG_EBRACK)) {}
if (p->error != 0) /* don't mess things up further */
return;
if (p->g->cflags&REG_ICASE) {
register int i;
register int ci;
for (i = p->g->csetsize - 1; i >= 0; i--)
if (CHIN(cs, i) && my_isalpha(p->charset,i)) {
ci = othercase(p->charset,i);
if (ci != i)
CHadd(cs, ci);
}
if (cs->multis != NULL)
mccase(p, cs);
}
if (invert) {
register int i;
for (i = p->g->csetsize - 1; i >= 0; i--)
if (CHIN(cs, i))
CHsub(cs, i);
else
CHadd(cs, i);
if (p->g->cflags&REG_NEWLINE)
CHsub(cs, '\n');
if (cs->multis != NULL)
mcinvert(p, cs);
}
assert(cs->multis == NULL); /* xxx */
if (nch(p, cs) == 1) { /* optimize singleton sets */
ordinary(p, firstch(p, cs));
freeset(p, cs);
} else
EMIT(OANYOF, freezeset(p, cs));
}
/*
- p_b_term - parse one term of a bracketed character list
== static void p_b_term(register struct parse *p, register cset *cs);
*/
static void
p_b_term(p, cs)
register struct parse *p;
register cset *cs;
{
register char c;
register char start, finish;
register int i;
/* classify what we've got */
switch ((MORE()) ? PEEK() : '\0') {
case '[':
c = (MORE2()) ? PEEK2() : '\0';
break;
case '-':
SETERROR(REG_ERANGE);
return; /* NOTE RETURN */
default:
c = '\0';
break;
}
switch (c) {
case ':': /* character class */
NEXT2();
if(REQUIRE(MORE(), REG_EBRACK)) {}
c = PEEK();
if(REQUIRE(c != '-' && c != ']', REG_ECTYPE)) {}
p_b_cclass(p, cs);
if(REQUIRE(MORE(), REG_EBRACK)) {}
if(REQUIRE(EATTWO(':', ']'), REG_ECTYPE)) {}
break;
case '=': /* equivalence class */
NEXT2();
if(REQUIRE(MORE(), REG_EBRACK)) {}
c = PEEK();
if(REQUIRE(c != '-' && c != ']', REG_ECOLLATE)) {}
p_b_eclass(p, cs);
if(REQUIRE(MORE(), REG_EBRACK)) {}
if(REQUIRE(EATTWO('=', ']'), REG_ECOLLATE)) {}
break;
default: /* symbol, ordinary character, or range */
/* xxx revision needed for multichar stuff */
start = p_b_symbol(p);
if (SEE('-') && MORE2() && PEEK2() != ']') {
/* range */
NEXT();
if (EAT('-'))
finish = '-';
else
finish = p_b_symbol(p);
} else
finish = start;
/* xxx what about signed chars here... */
if(REQUIRE(start <= finish, REG_ERANGE)) {}
for (i = start; i <= finish; i++)
CHadd(cs, i);
break;
}
}
/*
- p_b_cclass - parse a character-class name and deal with it
== static void p_b_cclass(register struct parse *p, register cset *cs);
*/
static void
p_b_cclass(p, cs)
register struct parse *p;
register cset *cs;
{
register char *sp = p->next;
register struct cclass *cp;
register size_t len;
while (MORE() && my_isalpha(p->charset,PEEK()))
NEXT();
len = p->next - sp;
for (cp = cclasses; cp->name != NULL; cp++)
if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
break;
if (cp->name == NULL) {
/* oops, didn't find it */
SETERROR(REG_ECTYPE);
return;
}
#ifndef USE_ORIG_REGEX_CODE
{
register size_t i;
for (i=1 ; i<256 ; i++)
if (p->charset->ctype[i+1] & cp->mask)
CHadd(cs, i);
}
#else
{
register char *u = (char*) cp->chars;
register char c;
while ((c = *u++) != '\0')
CHadd(cs, c);
for (u = (char*) cp->multis; *u != '\0'; u += strlen(u) + 1)
MCadd(p, cs, u);
}
#endif
}
/*
- p_b_eclass - parse an equivalence-class name and deal with it
== static void p_b_eclass(register struct parse *p, register cset *cs);
*
* This implementation is incomplete. xxx
*/
static void
p_b_eclass(p, cs)
register struct parse *p;
register cset *cs;
{
register char c;
c = p_b_coll_elem(p, '=');
CHadd(cs, c);
}
/*
- p_b_symbol - parse a character or [..]ed multicharacter collating symbol
== static char p_b_symbol(register struct parse *p);
*/
static char /* value of symbol */
p_b_symbol(p)
register struct parse *p;
{
register char value;
if(REQUIRE(MORE(), REG_EBRACK)) {}
if (!EATTWO('[', '.'))
return(GETNEXT());
/* collating symbol */
value = p_b_coll_elem(p, '.');
if(REQUIRE(EATTWO('.', ']'), REG_ECOLLATE)) {}
return(value);
}
/*
- p_b_coll_elem - parse a collating-element name and look it up
== static char p_b_coll_elem(register struct parse *p, int endc);
*/
static char /* value of collating element */
p_b_coll_elem(p, endc)
register struct parse *p;
int endc; /* name ended by endc,']' */
{
register char *sp = p->next;
register struct cname *cp;
#ifdef _WIN64
register __int64 len;
#else
register int len;
#endif
while (MORE() && !SEETWO(endc, ']'))
NEXT();
if (!MORE()) {
SETERROR(REG_EBRACK);
return(0);
}
len = p->next - sp;
for (cp = cnames; cp->name != NULL; cp++)
if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
return(cp->code); /* known name */
if (len == 1)
return(*sp); /* single character */
SETERROR(REG_ECOLLATE); /* neither */
return(0);
}
/*
- othercase - return the case counterpart of an alphabetic
== static char othercase(int ch);
*/
static char /* if no counterpart, return ch */
othercase(charset,ch)
CHARSET_INFO *charset;
int ch;
{
/*
In MySQL some multi-byte character sets
have 'ctype' array but don't have 'to_lower'
and 'to_upper' arrays. In this case we handle
only basic latin letters a..z and A..Z.
If 'to_lower' and 'to_upper' arrays are empty in a character set,
then my_isalpha(cs, ch) should never return TRUE for characters
other than basic latin letters. Otherwise it should be
considered as a mistake in character set definition.
*/
assert(my_isalpha(charset,ch));
if (my_isupper(charset,ch))
{
return(charset->to_lower ? my_tolower(charset,ch) :
ch - 'A' + 'a');
}
else if (my_islower(charset,ch))
{
return(charset->to_upper ? my_toupper(charset,ch) :
ch - 'a' + 'A');
}
else /* peculiar, but could happen */
return(ch);
}
/*
- bothcases - emit a dualcase version of a two-case character
== static void bothcases(register struct parse *p, int ch);
*
* Boy, is this implementation ever a kludge...
*/
static void
bothcases(p, ch)
register struct parse *p;
int ch;
{
register char *oldnext = p->next;
register char *oldend = p->end;
char bracket[3];
assert(othercase(p->charset, ch) != ch); /* p_bracket() would recurse */
p->next = bracket;
p->end = bracket+2;
bracket[0] = ch;
bracket[1] = ']';
bracket[2] = '\0';
p_bracket(p);
assert(p->next == bracket+2);
p->next = oldnext;
p->end = oldend;
}
/*
- ordinary - emit an ordinary character
== static void ordinary(register struct parse *p, register int ch);
*/
static void
ordinary(p, ch)
register struct parse *p;
register int ch;
{
register cat_t *cap = p->g->categories;
if ((p->g->cflags&REG_ICASE) && my_isalpha(p->charset,ch) &&
othercase(p->charset,ch) != ch)
bothcases(p, ch);
else {
EMIT(OCHAR, (unsigned char)ch);
if (cap[ch] == 0)
cap[ch] = p->g->ncategories++;
}
}
/*
- nonnewline - emit REG_NEWLINE version of OANY
== static void nonnewline(register struct parse *p);
*
* Boy, is this implementation ever a kludge...
*/
static void
nonnewline(p)
register struct parse *p;
{
register char *oldnext = p->next;
register char *oldend = p->end;
char bracket[4];
p->next = bracket;
p->end = bracket+3;
bracket[0] = '^';
bracket[1] = '\n';
bracket[2] = ']';
bracket[3] = '\0';
p_bracket(p);
assert(p->next == bracket+3);
p->next = oldnext;
p->end = oldend;
}
/*
- repeat - generate code for a bounded repetition, recursively if needed
== static void repeat(register struct parse *p, sopno start, int from, int to);
*/
static void
repeat(p, start, from, to)
register struct parse *p;
sopno start; /* operand from here to end of strip */
int from; /* repeated from this number */
int to; /* to this number of times (maybe RE_INFINITY) */
{
register sopno finish = HERE();
# define N 2
# define INF 3
# define REP(f, t) ((f)*8 + (t))
# define MAP(n) (((n) <= 1) ? (n) : ((n) == RE_INFINITY) ? INF : N)
register sopno copy;
if (p->error != 0) /* head off possible runaway recursion */
return;
assert(from <= to);
switch (REP(MAP(from), MAP(to))) {
case REP(0, 0): /* must be user doing this */
DROP(finish-start); /* drop the operand */
break;
case REP(0, 1): /* as x{1,1}? */
case REP(0, N): /* as x{1,n}? */
case REP(0, INF): /* as x{1,}? */
/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
INSERT(OCH_, start); /* offset is wrong... */
repeat(p, start+1, 1, to);
ASTERN(OOR1, start);
AHEAD(start); /* ... fix it */
EMIT(OOR2, 0);
AHEAD(THERE());
ASTERN(O_CH, THERETHERE());
break;
case REP(1, 1): /* trivial case */
/* done */
break;
case REP(1, N): /* as x?x{1,n-1} */
/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
INSERT(OCH_, start);
ASTERN(OOR1, start);
AHEAD(start);
EMIT(OOR2, 0); /* offset very wrong... */
AHEAD(THERE()); /* ...so fix it */
ASTERN(O_CH, THERETHERE());
copy = dupl(p, start+1, finish+1);
assert(copy == finish+4);
repeat(p, copy, 1, to-1);
break;
case REP(1, INF): /* as x+ */
INSERT(OPLUS_, start);
ASTERN(O_PLUS, start);
break;
case REP(N, N): /* as xx{m-1,n-1} */
copy = dupl(p, start, finish);
repeat(p, copy, from-1, to-1);
break;
case REP(N, INF): /* as xx{n-1,INF} */
copy = dupl(p, start, finish);
repeat(p, copy, from-1, to);
break;
default: /* "can't happen" */
SETERROR(REG_ASSERT); /* just in case */
break;
}
}
/*
- seterr - set an error condition
== static int seterr(register struct parse *p, int e);
*/
static int /* useless but makes type checking happy */
seterr(p, e)
register struct parse *p;
int e;
{
if (p->error == 0) /* keep earliest error condition */
p->error = e;
p->next = nuls; /* try to bring things to a halt */
p->end = nuls;
return(0); /* make the return value well-defined */
}
/*
- allocset - allocate a set of characters for []
== static cset *allocset(register struct parse *p);
*/
static cset *
allocset(p)
register struct parse *p;
{
register int no = p->g->ncsets++;
register size_t nc;
register size_t nbytes;
register cset *cs;
register size_t css = (size_t)p->g->csetsize;
register int i;
if (no >= p->ncsalloc) { /* need another column of space */
p->ncsalloc += CHAR_BIT;
nc = p->ncsalloc;
assert(nc % CHAR_BIT == 0);
nbytes = nc / CHAR_BIT * css;
if (p->g->sets == NULL)
p->g->sets = (cset *)malloc(nc * sizeof(cset));
else
p->g->sets = (cset *)realloc((char *)p->g->sets,
nc * sizeof(cset));
if (p->g->setbits == NULL)
p->g->setbits = (uch *)malloc(nbytes);
else {
p->g->setbits = (uch *)realloc((char *)p->g->setbits,
nbytes);
/* xxx this isn't right if setbits is now NULL */
for (i = 0; i < no; i++)
p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
}
if (p->g->sets != NULL && p->g->setbits != NULL)
(void) memset((char *)p->g->setbits + (nbytes - css),
0, css);
else {
no = 0;
SETERROR(REG_ESPACE);
/* caller's responsibility not to do set ops */
}
}
assert(p->g->sets != NULL); /* xxx */
cs = &p->g->sets[no];
cs->ptr = p->g->setbits + css*((no)/CHAR_BIT);
cs->mask = 1 << ((no) % CHAR_BIT);
cs->hash = 0;
cs->smultis = 0;
cs->multis = NULL;
return(cs);
}
/*
- freeset - free a now-unused set
== static void freeset(register struct parse *p, register cset *cs);
*/
static void
freeset(p, cs)
register struct parse *p;
register cset *cs;
{
register size_t i;
register cset *top = &p->g->sets[p->g->ncsets];
register size_t css = (size_t)p->g->csetsize;
for (i = 0; i < css; i++)
CHsub(cs, i);
if (cs == top-1) /* recover only the easy case */
p->g->ncsets--;
}
/*
- freezeset - final processing on a set of characters
== static int freezeset(register struct parse *p, register cset *cs);
*
* The main task here is merging identical sets. This is usually a waste
* of time (although the hash code minimizes the overhead), but can win
* big if REG_ICASE is being used. REG_ICASE, by the way, is why the hash
* is done using addition rather than xor -- all ASCII [aA] sets xor to
* the same value!
*/
static int /* set number */
freezeset(p, cs)
register struct parse *p;
register cset *cs;
{
register uch h = cs->hash;
register size_t i;
register cset *top = &p->g->sets[p->g->ncsets];
register cset *cs2;
register size_t css = (size_t)p->g->csetsize;
/* look for an earlier one which is the same */
for (cs2 = &p->g->sets[0]; cs2 < top; cs2++)
if (cs2->hash == h && cs2 != cs) {
/* maybe */
for (i = 0; i < css; i++)
if (!!CHIN(cs2, i) != !!CHIN(cs, i))
break; /* no */
if (i == css)
break; /* yes */
}
if (cs2 < top) { /* found one */
freeset(p, cs);
cs = cs2;
}
return((int)(cs - p->g->sets));
}
/*
- firstch - return first character in a set (which must have at least one)
== static int firstch(register struct parse *p, register cset *cs);
*/
static int /* character; there is no "none" value */
firstch(p, cs)
register struct parse *p;
register cset *cs;
{
register size_t i;
register size_t css = (size_t)p->g->csetsize;
for (i = 0; i < css; i++)
if (CHIN(cs, i))
return((char)i);
assert(never);
return(0); /* arbitrary */
}
/*
- nch - number of characters in a set
== static int nch(register struct parse *p, register cset *cs);
*/
static int
nch(p, cs)
register struct parse *p;
register cset *cs;
{
register size_t i;
register size_t css = (size_t)p->g->csetsize;
register int n = 0;
for (i = 0; i < css; i++)
if (CHIN(cs, i))
n++;
return(n);
}
#ifdef USE_ORIG_REGEX_CODE
/*
- mcadd - add a collating element to a cset
== static void mcadd(register struct parse *p, register cset *cs, \
== register char *cp);
*/
static void
mcadd(p, cs, cp)
register struct parse *p;
register cset *cs;
register char *cp;
{
register size_t oldend = cs->smultis;
cs->smultis += strlen(cp) + 1;
if (cs->multis == NULL)
cs->multis = malloc(cs->smultis);
else
cs->multis = realloc(cs->multis, cs->smultis);
if (cs->multis == NULL) {
SETERROR(REG_ESPACE);
return;
}
(void) strcpy(cs->multis + oldend - 1, cp);
cs->multis[cs->smultis - 1] = '\0';
}
#endif
#ifdef NOT_USED
/*
- mcsub - subtract a collating element from a cset
== static void mcsub(register cset *cs, register char *cp);
*/
static void
mcsub(cs, cp)
register cset *cs;
register char *cp;
{
register char *fp = mcfind(cs, cp);
register size_t len = strlen(fp);
assert(fp != NULL);
(void) memmove(fp, fp + len + 1,
cs->smultis - (fp + len + 1 - cs->multis));
cs->smultis -= len;
if (cs->smultis == 0) {
free(cs->multis);
cs->multis = NULL;
return;
}
cs->multis = realloc(cs->multis, cs->smultis);
assert(cs->multis != NULL);
}
/*
- mcin - is a collating element in a cset?
== static int mcin(register cset *cs, register char *cp);
*/
static int
mcin(cs, cp)
register cset *cs;
register char *cp;
{
return(mcfind(cs, cp) != NULL);
}
/*
- mcfind - find a collating element in a cset
== static char *mcfind(register cset *cs, register char *cp);
*/
static char *
mcfind(cs, cp)
register cset *cs;
register char *cp;
{
register char *p;
if (cs->multis == NULL)
return(NULL);
for (p = cs->multis; *p != '\0'; p += strlen(p) + 1)
if (strcmp(cp, p) == 0)
return(p);
return(NULL);
}
#endif
/*
- mcinvert - invert the list of collating elements in a cset
== static void mcinvert(register struct parse *p, register cset *cs);
*
* This would have to know the set of possibilities. Implementation
* is deferred.
*/
static void
mcinvert(p, cs)
register struct parse *p __attribute__((unused));
register cset *cs __attribute__((unused));
{
assert(cs->multis == NULL); /* xxx */
}
/*
- mccase - add case counterparts of the list of collating elements in a cset
== static void mccase(register struct parse *p, register cset *cs);
*
* This would have to know the set of possibilities. Implementation
* is deferred.
*/
static void
mccase(p, cs)
register struct parse *p __attribute__((unused));
register cset *cs __attribute__((unused));
{
assert(cs->multis == NULL); /* xxx */
}
/*
- isinsets - is this character in any sets?
== static int isinsets(register struct re_guts *g, int c);
*/
static int /* predicate */
isinsets(g, c)
register struct re_guts *g;
int c;
{
register uch *col;
register int i;
register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
register unsigned uc = (unsigned char)c;
for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
if (col[uc] != 0)
return(1);
return(0);
}
/*
- samesets - are these two characters in exactly the same sets?
== static int samesets(register struct re_guts *g, int c1, int c2);
*/
static int /* predicate */
samesets(g, c1, c2)
register struct re_guts *g;
int c1;
int c2;
{
register uch *col;
register int i;
register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
register unsigned uc1 = (unsigned char)c1;
register unsigned uc2 = (unsigned char)c2;
for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
if (col[uc1] != col[uc2])
return(0);
return(1);
}
/*
- categorize - sort out character categories
== static void categorize(struct parse *p, register struct re_guts *g);
*/
static void
categorize(p, g)
struct parse *p;
register struct re_guts *g;
{
register cat_t *cats = g->categories;
register int c;
register int c2;
register cat_t cat;
/* avoid making error situations worse */
if (p->error != 0)
return;
for (c = CHAR_MIN; c <= CHAR_MAX; c++)
if (cats[c] == 0 && isinsets(g, c)) {
cat = g->ncategories++;
cats[c] = cat;
for (c2 = c+1; c2 <= CHAR_MAX; c2++)
if (cats[c2] == 0 && samesets(g, c, c2))
cats[c2] = cat;
}
}
/*
- dupl - emit a duplicate of a bunch of sops
== static sopno dupl(register struct parse *p, sopno start, sopno finish);
*/
static sopno /* start of duplicate */
dupl(p, start, finish)
register struct parse *p;
sopno start; /* from here */
sopno finish; /* to this less one */
{
register sopno ret = HERE();
register sopno len = finish - start;
assert(finish >= start);
if (len == 0)
return(ret);
enlarge(p, p->ssize + len); /* this many unexpected additions */
assert(p->ssize >= p->slen + len);
(void) memcpy((char *)(p->strip + p->slen),
(char *)(p->strip + start), (size_t)len*sizeof(sop));
p->slen += len;
return(ret);
}
/*
- doemit - emit a strip operator
== static void doemit(register struct parse *p, sop op, size_t opnd);
*
* It might seem better to implement this as a macro with a function as
* hard-case backup, but it's just too big and messy unless there are
* some changes to the data structures. Maybe later.
*/
static void
doemit(p, op, opnd)
register struct parse *p;
sop op;
size_t opnd;
{
/* avoid making error situations worse */
if (p->error != 0)
return;
/* deal with oversize operands ("can't happen", more or less) */
assert(opnd < 1<<OPSHIFT);
/* deal with undersized strip */
if (p->slen >= p->ssize)
enlarge(p, (p->ssize+1) / 2 * 3); /* +50% */
assert(p->slen < p->ssize);
/* finally, it's all reduced to the easy case */
p->strip[p->slen++] = SOP(op, opnd);
}
/*
- doinsert - insert a sop into the strip
== static void doinsert(register struct parse *p, sop op, size_t opnd, sopno pos);
*/
static void
doinsert(p, op, opnd, pos)
register struct parse *p;
sop op;
size_t opnd;
sopno pos;
{
register sopno sn;
register sop s;
register int i;
/* avoid making error situations worse */
if (p->error != 0)
return;
sn = HERE();
EMIT(op, opnd); /* do checks, ensure space */
assert(HERE() == sn+1);
s = p->strip[sn];
/* adjust paren pointers */
assert(pos > 0);
for (i = 1; i < NPAREN; i++) {
if (p->pbegin[i] >= pos) {
p->pbegin[i]++;
}
if (p->pend[i] >= pos) {
p->pend[i]++;
}
}
{
int length=(HERE()-pos-1)*sizeof(sop);
bmove_upp((uchar *) &p->strip[pos+1]+length,
(uchar *) &p->strip[pos]+length,
length);
}
#ifdef OLD_CODE
memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
(HERE()-pos-1)*sizeof(sop));
#endif
p->strip[pos] = s;
}
/*
- dofwd - complete a forward reference
== static void dofwd(register struct parse *p, sopno pos, sop value);
*/
static void
dofwd(p, pos, value)
register struct parse *p;
register sopno pos;
sop value;
{
/* avoid making error situations worse */
if (p->error != 0)
return;
assert(value < 1<<OPSHIFT);
p->strip[pos] = OP(p->strip[pos]) | value;
}
/*
- enlarge - enlarge the strip
== static void enlarge(register struct parse *p, sopno size);
*/
static void
enlarge(p, size)
register struct parse *p;
register sopno size;
{
register sop *sp;
if (p->ssize >= size)
return;
sp = (sop *)realloc(p->strip, size*sizeof(sop));
if (sp == NULL) {
SETERROR(REG_ESPACE);
return;
}
p->strip = sp;
p->ssize = size;
}
/*
- stripsnug - compact the strip
== static void stripsnug(register struct parse *p, register struct re_guts *g);
*/
static void
stripsnug(p, g)
register struct parse *p;
register struct re_guts *g;
{
g->nstates = p->slen;
g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof(sop));
if (g->strip == NULL) {
SETERROR(REG_ESPACE);
g->strip = p->strip;
}
}
/*
- findmust - fill in must and mlen with longest mandatory literal string
== static void findmust(register struct parse *p, register struct re_guts *g);
*
* This algorithm could do fancy things like analyzing the operands of |
* for common subsequences. Someday. This code is simple and finds most
* of the interesting cases.
*
* Note that must and mlen got initialized during setup.
*/
static void
findmust(p, g)
struct parse *p;
register struct re_guts *g;
{
register sop *scan;
sop *UNINIT_VAR(start);
register sop *UNINIT_VAR(newstart);
register sopno newlen;
register sop s;
register char *cp;
register sopno i;
/* avoid making error situations worse */
if (p->error != 0)
return;
/* find the longest OCHAR sequence in strip */
newlen = 0;
scan = g->strip + 1;
do {
s = *scan++;
switch (OP(s)) {
case OCHAR: /* sequence member */
if (newlen == 0) /* new sequence */
newstart = scan - 1;
newlen++;
break;
case OPLUS_: /* things that don't break one */
case OLPAREN:
case ORPAREN:
break;
case OQUEST_: /* things that must be skipped */
case OCH_:
scan--;
do {
scan += OPND(s);
s = *scan;
/* assert() interferes w debug printouts */
if (OP(s) != O_QUEST && OP(s) != O_CH &&
OP(s) != OOR2) {
g->iflags |= BAD;
return;
}
} while (OP(s) != O_QUEST && OP(s) != O_CH);
/* fallthrough */
default: /* things that break a sequence */
if (newlen > g->mlen) { /* ends one */
start = newstart;
g->mlen = newlen;
}
newlen = 0;
break;
}
} while (OP(s) != OEND);
if (g->mlen == 0) /* there isn't one */
return;
/* turn it into a character string */
g->must = malloc((size_t)g->mlen + 1);
if (g->must == NULL) { /* argh; just forget it */
g->mlen = 0;
return;
}
cp = g->must;
scan = start;
for (i = g->mlen; i > 0; i--) {
while (OP(s = *scan++) != OCHAR)
continue;
assert(cp < g->must + g->mlen);
*cp++ = (char)OPND(s);
}
assert(cp == g->must + g->mlen);
*cp++ = '\0'; /* just on general principles */
}
/*
- pluscount - count + nesting
== static sopno pluscount(register struct parse *p, register struct re_guts *g);
*/
static sopno /* nesting depth */
pluscount(p, g)
struct parse *p;
register struct re_guts *g;
{
register sop *scan;
register sop s;
register sopno plusnest = 0;
register sopno maxnest = 0;
if (p->error != 0)
return(0); /* there may not be an OEND */
scan = g->strip + 1;
do {
s = *scan++;
switch (OP(s)) {
case OPLUS_:
plusnest++;
break;
case O_PLUS:
if (plusnest > maxnest)
maxnest = plusnest;
plusnest--;
break;
}
} while (OP(s) != OEND);
if (plusnest != 0)
g->iflags |= BAD;
return(maxnest);
}