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wxWidgets/src/regex/regc_lex.c
Ryan Norton 38d679fdb5 Tcl regex lib 
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3949 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
1999-10-13 02:22:17 +00:00

1147 lines
24 KiB
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/*
* lexical analyzer
* This file is #included by regcomp.c.
*
* Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
*
* Development of this software was funded, in part, by Cray Research Inc.,
* UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
* Corporation, none of whom are responsible for the results. The author
* thanks all of them.
*
* Redistribution and use in source and binary forms -- with or without
* modification -- are permitted for any purpose, provided that
* redistributions in source form retain this entire copyright notice and
* indicate the origin and nature of any modifications.
*
* I'd appreciate being given credit for this package in the documentation
* of software which uses it, but that is not a requirement.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Header$
*
*/
/* scanning macros (know about v) */
#define ATEOS() (v->now >= v->stop)
#define HAVE(n) (v->stop - v->now >= (n))
#define NEXT1(c) (!ATEOS() && *v->now == CHR(c))
#define NEXT2(a,b) (HAVE(2) && *v->now == CHR(a) && *(v->now+1) == CHR(b))
#define NEXT3(a,b,c) (HAVE(3) && *v->now == CHR(a) && \
*(v->now+1) == CHR(b) && \
*(v->now+2) == CHR(c))
#define SET(c) (v->nexttype = (c))
#define SETV(c, n) (v->nexttype = (c), v->nextvalue = (n))
#define RET(c) return (SET(c), 1)
#define RETV(c, n) return (SETV(c, n), 1)
#define FAILW(e) return (ERR(e), 0) /* ERR does SET(EOS) */
#define LASTTYPE(t) (v->lasttype == (t))
/* lexical contexts */
#define L_ERE 1 /* mainline ERE/ARE */
#define L_BRE 2 /* mainline BRE */
#define L_Q 3 /* REG_QUOTE */
#define L_EBND 4 /* ERE/ARE bound */
#define L_BBND 5 /* BRE bound */
#define L_BRACK 6 /* brackets */
#define L_CEL 7 /* collating element */
#define L_ECL 8 /* equivalence class */
#define L_CCL 9 /* character class */
#define INTOCON(c) (v->lexcon = (c))
#define INCON(con) (v->lexcon == (con))
/* construct pointer past end of chr array */
#define ENDOF(array) ((array) + sizeof(array)/sizeof(chr))
/*
* lexstart - set up lexical stuff, scan leading options
*/
static void
lexstart(struct vars * v)
{
prefixes(v); /* may turn on new type bits etc. */
NOERR();
if (v->cflags & REG_QUOTE)
{
assert(!(v->cflags & (REG_ADVANCED | REG_EXPANDED | REG_NEWLINE)));
INTOCON(L_Q);
}
else if (v->cflags & REG_EXTENDED)
{
assert(!(v->cflags & REG_QUOTE));
INTOCON(L_ERE);
}
else
{
assert(!(v->cflags & (REG_QUOTE | REG_ADVF)));
INTOCON(L_BRE);
}
v->nexttype = EMPTY; /* remember we were at the start */
next(v); /* set up the first token */
}
/*
* prefixes - implement various special prefixes
*/
static void
prefixes(struct vars * v)
{
/* literal string doesn't get any of this stuff */
if (v->cflags & REG_QUOTE)
return;
/* initial "***" gets special things */
if (HAVE(4) && NEXT3('*', '*', '*'))
switch (*(v->now + 3))
{
case CHR('?'): /* "***?" error, msg shows version */
ERR(REG_BADPAT);
return; /* proceed no further */
break;
case CHR('='): /* "***=" shifts to literal string */
NOTE(REG_UNONPOSIX);
v->cflags |= REG_QUOTE;
v->cflags &= ~(REG_ADVANCED | REG_EXPANDED | REG_NEWLINE);
v->now += 4;
return; /* and there can be no more prefixes */
break;
case CHR(':'): /* "***:" shifts to AREs */
NOTE(REG_UNONPOSIX);
v->cflags |= REG_ADVANCED;
v->now += 4;
break;
default: /* otherwise *** is just an error */
ERR(REG_BADRPT);
return;
break;
}
/* BREs and EREs don't get embedded options */
if ((v->cflags & REG_ADVANCED) != REG_ADVANCED)
return;
/* embedded options (AREs only) */
if (HAVE(3) && NEXT2('(', '?') && iscalpha(*(v->now + 2)))
{
NOTE(REG_UNONPOSIX);
v->now += 2;
for (; !ATEOS() && iscalpha(*v->now); v->now++)
switch (*v->now)
{
case CHR('b'): /* BREs (but why???) */
v->cflags &= ~(REG_ADVANCED | REG_QUOTE);
break;
case CHR('c'): /* case sensitive */
v->cflags &= ~REG_ICASE;
break;
case CHR('e'): /* plain EREs */
v->cflags |= REG_EXTENDED;
v->cflags &= ~(REG_ADVF | REG_QUOTE);
break;
case CHR('i'): /* case insensitive */
v->cflags |= REG_ICASE;
break;
case CHR('m'): /* Perloid synonym for n */
case CHR('n'): /* \n affects ^ $ . [^ */
v->cflags |= REG_NEWLINE;
break;
case CHR('p'): /* ~Perl, \n affects . [^ */
v->cflags |= REG_NLSTOP;
v->cflags &= ~REG_NLANCH;
break;
case CHR('q'): /* literal string */
v->cflags |= REG_QUOTE;
v->cflags &= ~REG_ADVANCED;
break;
case CHR('s'): /* single line, \n ordinary */
v->cflags &= ~REG_NEWLINE;
break;
case CHR('t'): /* tight syntax */
v->cflags &= ~REG_EXPANDED;
break;
case CHR('w'): /* weird, \n affects ^ $ only */
v->cflags &= ~REG_NLSTOP;
v->cflags |= REG_NLANCH;
break;
case CHR('x'): /* expanded syntax */
v->cflags |= REG_EXPANDED;
break;
default:
ERR(REG_BADOPT);
return;
}
if (!NEXT1(')'))
{
ERR(REG_BADOPT);
return;
}
v->now++;
if (v->cflags & REG_QUOTE)
v->cflags &= ~(REG_EXPANDED | REG_NEWLINE);
}
}
/*
* lexnest - "call a subroutine", interpolating string at the lexical level
*
* Note, this is not a very general facility. There are a number of
* implicit assumptions about what sorts of strings can be subroutines.
*/
static void
lexnest(struct vars * v,
chr *beginp, /* start of interpolation */
chr *endp) /* one past end of interpolation */
{
assert(v->savenow == NULL); /* only one level of nesting */
v->savenow = v->now;
v->savestop = v->stop;
v->now = beginp;
v->stop = endp;
}
/*
* string constants to interpolate as expansions of things like \d
*/
static chr backd[] = { /* \d */
CHR('['), CHR('['), CHR(':'),
CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'),
CHR(':'), CHR(']'), CHR(']')
};
static chr backD[] = { /* \D */
CHR('['), CHR('^'), CHR('['), CHR(':'),
CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'),
CHR(':'), CHR(']'), CHR(']')
};
static chr brbackd[] = { /* \d within brackets */
CHR('['), CHR(':'),
CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'),
CHR(':'), CHR(']')
};
static chr backs[] = { /* \s */
CHR('['), CHR('['), CHR(':'),
CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'),
CHR(':'), CHR(']'), CHR(']')
};
static chr backS[] = { /* \S */
CHR('['), CHR('^'), CHR('['), CHR(':'),
CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'),
CHR(':'), CHR(']'), CHR(']')
};
static chr brbacks[] = { /* \s within brackets */
CHR('['), CHR(':'),
CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'),
CHR(':'), CHR(']')
};
static chr backw[] = { /* \w */
CHR('['), CHR('['), CHR(':'),
CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'),
CHR(':'), CHR(']'), CHR('_'), CHR(']')
};
static chr backW[] = { /* \W */
CHR('['), CHR('^'), CHR('['), CHR(':'),
CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'),
CHR(':'), CHR(']'), CHR('_'), CHR(']')
};
static chr brbackw[] = { /* \w within brackets */
CHR('['), CHR(':'),
CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'),
CHR(':'), CHR(']'), CHR('_')
};
/*
* lexword - interpolate a bracket expression for word characters
* Possibly ought to inquire whether there is a "word" character class.
*/
static void
lexword(struct vars * v)
{
lexnest(v, backw, ENDOF(backw));
}
/*
* next - get next token
*/
static int /* 1 normal, 0 failure */
next(struct vars * v)
{
chr c;
/* errors yield an infinite sequence of failures */
if (ISERR())
return 0; /* the error has set nexttype to EOS */
/* remember flavor of last token */
v->lasttype = v->nexttype;
/* REG_BOSONLY */
if (v->nexttype == EMPTY && (v->cflags & REG_BOSONLY))
{
/* at start of a REG_BOSONLY RE */
RETV(SBEGIN, 0); /* same as \A */
}
/* if we're nested and we've hit end, return to outer level */
if (v->savenow != NULL && ATEOS())
{
v->now = v->savenow;
v->stop = v->savestop;
v->savenow = v->savestop = NULL;
}
/* skip white space etc. if appropriate (not in literal or []) */
if (v->cflags & REG_EXPANDED)
switch (v->lexcon)
{
case L_ERE:
case L_BRE:
case L_EBND:
case L_BBND:
skip(v);
break;
}
/* handle EOS, depending on context */
if (ATEOS())
{
switch (v->lexcon)
{
case L_ERE:
case L_BRE:
case L_Q:
RET(EOS);
break;
case L_EBND:
case L_BBND:
FAILW(REG_EBRACE);
break;
case L_BRACK:
case L_CEL:
case L_ECL:
case L_CCL:
FAILW(REG_EBRACK);
break;
}
assert(NOTREACHED);
}
/* okay, time to actually get a character */
c = *v->now++;
/* deal with the easy contexts, punt EREs to code below */
switch (v->lexcon)
{
case L_BRE: /* punt BREs to separate function */
return brenext(v, c);
break;
case L_ERE: /* see below */
break;
case L_Q: /* literal strings are easy */
RETV(PLAIN, c);
break;
case L_BBND: /* bounds are fairly simple */
case L_EBND:
switch (c)
{
case CHR('0'):
case CHR('1'):
case CHR('2'):
case CHR('3'):
case CHR('4'):
case CHR('5'):
case CHR('6'):
case CHR('7'):
case CHR('8'):
case CHR('9'):
RETV(DIGIT, (chr) DIGITVAL(c));
break;
case CHR(','):
RET(',');
break;
case CHR('}'): /* ERE bound ends with } */
if (INCON(L_EBND))
{
INTOCON(L_ERE);
if ((v->cflags & REG_ADVF) && NEXT1('?'))
{
v->now++;
NOTE(REG_UNONPOSIX);
RETV('}', 0);
}
RETV('}', 1);
}
else
FAILW(REG_BADBR);
break;
case CHR('\\'): /* BRE bound ends with \} */
if (INCON(L_BBND) && NEXT1('}'))
{
v->now++;
INTOCON(L_BRE);
RET('}');
}
else
FAILW(REG_BADBR);
break;
default:
FAILW(REG_BADBR);
break;
}
assert(NOTREACHED);
break;
case L_BRACK: /* brackets are not too hard */
switch (c)
{
case CHR(']'):
if (LASTTYPE('['))
RETV(PLAIN, c);
else
{
INTOCON((v->cflags & REG_EXTENDED) ?
L_ERE : L_BRE);
RET(']');
}
break;
case CHR('\\'):
NOTE(REG_UBBS);
if (!(v->cflags & REG_ADVF))
RETV(PLAIN, c);
NOTE(REG_UNONPOSIX);
if (ATEOS())
FAILW(REG_EESCAPE);
(DISCARD) lexescape(v);
switch (v->nexttype)
{ /* not all escapes okay here */
case PLAIN:
return 1;
break;
case CCLASS:
switch (v->nextvalue)
{
case 'd':
lexnest(v, brbackd, ENDOF(brbackd));
break;
case 's':
lexnest(v, brbacks, ENDOF(brbacks));
break;
case 'w':
lexnest(v, brbackw, ENDOF(brbackw));
break;
default:
FAILW(REG_EESCAPE);
break;
}
/* lexnest done, back up and try again */
v->nexttype = v->lasttype;
return next(v);
break;
}
/* not one of the acceptable escapes */
FAILW(REG_EESCAPE);
break;
case CHR('-'):
if (LASTTYPE('[') || NEXT1(']'))
RETV(PLAIN, c);
else
RETV(RANGE, c);
break;
case CHR('['):
if (ATEOS())
FAILW(REG_EBRACK);
switch (*v->now++)
{
case CHR('.'):
INTOCON(L_CEL);
/* might or might not be locale-specific */
RET(COLLEL);
break;
case CHR('='):
INTOCON(L_ECL);
NOTE(REG_ULOCALE);
RET(ECLASS);
break;
case CHR(':'):
INTOCON(L_CCL);
NOTE(REG_ULOCALE);
RET(CCLASS);
break;
default: /* oops */
v->now--;
RETV(PLAIN, c);
break;
}
assert(NOTREACHED);
break;
default:
RETV(PLAIN, c);
break;
}
assert(NOTREACHED);
break;
case L_CEL: /* collating elements are easy */
if (c == CHR('.') && NEXT1(']'))
{
v->now++;
INTOCON(L_BRACK);
RETV(END, '.');
}
else
RETV(PLAIN, c);
break;
case L_ECL: /* ditto equivalence classes */
if (c == CHR('=') && NEXT1(']'))
{
v->now++;
INTOCON(L_BRACK);
RETV(END, '=');
}
else
RETV(PLAIN, c);
break;
case L_CCL: /* ditto character classes */
if (c == CHR(':') && NEXT1(']'))
{
v->now++;
INTOCON(L_BRACK);
RETV(END, ':');
}
else
RETV(PLAIN, c);
break;
default:
assert(NOTREACHED);
break;
}
/* that got rid of everything except EREs and AREs */
assert(INCON(L_ERE));
/* deal with EREs and AREs, except for backslashes */
switch (c)
{
case CHR('|'):
RET('|');
break;
case CHR('*'):
if ((v->cflags & REG_ADVF) && NEXT1('?'))
{
v->now++;
NOTE(REG_UNONPOSIX);
RETV('*', 0);
}
RETV('*', 1);
break;
case CHR('+'):
if ((v->cflags & REG_ADVF) && NEXT1('?'))
{
v->now++;
NOTE(REG_UNONPOSIX);
RETV('+', 0);
}
RETV('+', 1);
break;
case CHR('?'):
if ((v->cflags & REG_ADVF) && NEXT1('?'))
{
v->now++;
NOTE(REG_UNONPOSIX);
RETV('?', 0);
}
RETV('?', 1);
break;
case CHR('{'): /* bounds start or plain character */
if (v->cflags & REG_EXPANDED)
skip(v);
if (ATEOS() || !iscdigit(*v->now))
{
NOTE(REG_UBRACES);
NOTE(REG_UUNSPEC);
RETV(PLAIN, c);
}
else
{
NOTE(REG_UBOUNDS);
INTOCON(L_EBND);
RET('{');
}
assert(NOTREACHED);
break;
case CHR('('): /* parenthesis, or advanced extension */
if ((v->cflags & REG_ADVF) && NEXT1('?'))
{
NOTE(REG_UNONPOSIX);
v->now++;
switch (*v->now++)
{
case CHR(':'): /* non-capturing paren */
RETV('(', 0);
break;
case CHR('#'): /* comment */
while (!ATEOS() && *v->now != CHR(')'))
v->now++;
if (!ATEOS())
v->now++;
assert(v->nexttype == v->lasttype);
return next(v);
break;
case CHR('='): /* positive lookahead */
NOTE(REG_ULOOKAHEAD);
RETV(LACON, 1);
break;
case CHR('!'): /* negative lookahead */
NOTE(REG_ULOOKAHEAD);
RETV(LACON, 0);
break;
default:
FAILW(REG_BADRPT);
break;
}
assert(NOTREACHED);
}
if (v->cflags & REG_NOSUB)
RETV('(', 0); /* all parens non-capturing */
else
RETV('(', 1);
break;
case CHR(')'):
if (LASTTYPE('('))
NOTE(REG_UUNSPEC);
RETV(')', c);
break;
case CHR('['): /* easy except for [[:<:]] and [[:>:]] */
if (HAVE(6) && *(v->now + 0) == CHR('[') &&
*(v->now + 1) == CHR(':') &&
(*(v->now + 2) == CHR('<') ||
*(v->now + 2) == CHR('>')) &&
*(v->now + 3) == CHR(':') &&
*(v->now + 4) == CHR(']') &&
*(v->now + 5) == CHR(']'))
{
c = *(v->now + 2);
v->now += 6;
NOTE(REG_UNONPOSIX);
RET((c == CHR('<')) ? '<' : '>');
}
INTOCON(L_BRACK);
if (NEXT1('^'))
{
v->now++;
RETV('[', 0);
}
RETV('[', 1);
break;
case CHR('.'):
RET('.');
break;
case CHR('^'):
RET('^');
break;
case CHR('$'):
RET('$');
break;
case CHR('\\'): /* mostly punt backslashes to code below */
if (ATEOS())
FAILW(REG_EESCAPE);
break;
default: /* ordinary character */
RETV(PLAIN, c);
break;
}
/* ERE/ARE backslash handling; backslash already eaten */
assert(!ATEOS());
if (!(v->cflags & REG_ADVF))
{ /* only AREs have non-trivial escapes */
if (iscalnum(*v->now))
{
NOTE(REG_UBSALNUM);
NOTE(REG_UUNSPEC);
}
RETV(PLAIN, *v->now++);
}
(DISCARD) lexescape(v);
if (ISERR())
FAILW(REG_EESCAPE);
if (v->nexttype == CCLASS)
{ /* fudge at lexical level */
switch (v->nextvalue)
{
case 'd':
lexnest(v, backd, ENDOF(backd));
break;
case 'D':
lexnest(v, backD, ENDOF(backD));
break;
case 's':
lexnest(v, backs, ENDOF(backs));
break;
case 'S':
lexnest(v, backS, ENDOF(backS));
break;
case 'w':
lexnest(v, backw, ENDOF(backw));
break;
case 'W':
lexnest(v, backW, ENDOF(backW));
break;
default:
assert(NOTREACHED);
FAILW(REG_ASSERT);
break;
}
/* lexnest done, back up and try again */
v->nexttype = v->lasttype;
return next(v);
}
/* otherwise, lexescape has already done the work */
return !ISERR();
}
/*
* lexescape - parse an ARE backslash escape (backslash already eaten)
* Note slightly nonstandard use of the CCLASS type code.
*/
static int /* not actually used, but convenient for
* RETV */
lexescape(struct vars * v)
{
chr c;
static chr alert[] = {
CHR('a'), CHR('l'), CHR('e'), CHR('r'), CHR('t')
};
static chr esc[] = {
CHR('E'), CHR('S'), CHR('C')
};
chr *save;
assert(v->cflags & REG_ADVF);
assert(!ATEOS());
c = *v->now++;
if (!iscalnum(c))
RETV(PLAIN, c);
NOTE(REG_UNONPOSIX);
switch (c)
{
case CHR('a'):
RETV(PLAIN, chrnamed(v, alert, ENDOF(alert), CHR('\007')));
break;
case CHR('A'):
RETV(SBEGIN, 0);
break;
case CHR('b'):
RETV(PLAIN, CHR('\b'));
break;
case CHR('B'):
RETV(PLAIN, CHR('\\'));
break;
case CHR('c'):
NOTE(REG_UUNPORT);
if (ATEOS())
FAILW(REG_EESCAPE);
RETV(PLAIN, (chr) (*v->now++ & 037));
break;
case CHR('d'):
NOTE(REG_ULOCALE);
RETV(CCLASS, 'd');
break;
case CHR('D'):
NOTE(REG_ULOCALE);
RETV(CCLASS, 'D');
break;
case CHR('e'):
NOTE(REG_UUNPORT);
RETV(PLAIN, chrnamed(v, esc, ENDOF(esc), CHR('\033')));
break;
case CHR('f'):
RETV(PLAIN, CHR('\f'));
break;
case CHR('m'):
RET('<');
break;
case CHR('M'):
RET('>');
break;
case CHR('n'):
RETV(PLAIN, CHR('\n'));
break;
case CHR('r'):
RETV(PLAIN, CHR('\r'));
break;
case CHR('s'):
NOTE(REG_ULOCALE);
RETV(CCLASS, 's');
break;
case CHR('S'):
NOTE(REG_ULOCALE);
RETV(CCLASS, 'S');
break;
case CHR('t'):
RETV(PLAIN, CHR('\t'));
break;
case CHR('u'):
c = lexdigits(v, 16, 4, 4);
if (ISERR())
FAILW(REG_EESCAPE);
RETV(PLAIN, c);
break;
case CHR('U'):
c = lexdigits(v, 16, 8, 8);
if (ISERR())
FAILW(REG_EESCAPE);
RETV(PLAIN, c);
break;
case CHR('v'):
RETV(PLAIN, CHR('\v'));
break;
case CHR('w'):
NOTE(REG_ULOCALE);
RETV(CCLASS, 'w');
break;
case CHR('W'):
NOTE(REG_ULOCALE);
RETV(CCLASS, 'W');
break;
case CHR('x'):
NOTE(REG_UUNPORT);
c = lexdigits(v, 16, 1, 255); /* REs >255 long outside
* spec */
if (ISERR())
FAILW(REG_EESCAPE);
RETV(PLAIN, c);
break;
case CHR('y'):
NOTE(REG_ULOCALE);
RETV(WBDRY, 0);
break;
case CHR('Y'):
NOTE(REG_ULOCALE);
RETV(NWBDRY, 0);
break;
case CHR('Z'):
RETV(SEND, 0);
break;
case CHR('1'):
case CHR('2'):
case CHR('3'):
case CHR('4'):
case CHR('5'):
case CHR('6'):
case CHR('7'):
case CHR('8'):
case CHR('9'):
save = v->now;
v->now--; /* put first digit back */
c = lexdigits(v, 10, 1, 255); /* REs >255 long outside
* spec */
if (ISERR())
FAILW(REG_EESCAPE);
/* ugly heuristic (first test is "exactly 1 digit?") */
if (v->now - save == 0 || (int) c <= v->nsubexp)
{
NOTE(REG_UBACKREF);
RETV(BACKREF, (chr) c);
}
/* oops, doesn't look like it's a backref after all... */
v->now = save;
/* and fall through into octal number */
case CHR('0'):
NOTE(REG_UUNPORT);
v->now--; /* put first digit back */
c = lexdigits(v, 8, 1, 3);
if (ISERR())
FAILW(REG_EESCAPE);
RETV(PLAIN, c);
break;
default:
assert(iscalpha(c));
FAILW(REG_EESCAPE); /* unknown alphabetic escape */
break;
}
assert(NOTREACHED);
}
/*
* lexdigits - slurp up digits and return chr value
*/
static chr /* chr value; errors signalled via ERR */
lexdigits(struct vars * v,
int base,
int minlen,
int maxlen)
{
uchr n; /* unsigned to avoid overflow misbehavior */
int len;
chr c;
int d;
const uchr ub = (uchr) base;
n = 0;
for (len = 0; len < maxlen && !ATEOS(); len++)
{
c = *v->now++;
switch (c)
{
case CHR('0'):
case CHR('1'):
case CHR('2'):
case CHR('3'):
case CHR('4'):
case CHR('5'):
case CHR('6'):
case CHR('7'):
case CHR('8'):
case CHR('9'):
d = DIGITVAL(c);
break;
case CHR('a'):
case CHR('A'):
d = 10;
break;
case CHR('b'):
case CHR('B'):
d = 11;
break;
case CHR('c'):
case CHR('C'):
d = 12;
break;
case CHR('d'):
case CHR('D'):
d = 13;
break;
case CHR('e'):
case CHR('E'):
d = 14;
break;
case CHR('f'):
case CHR('F'):
d = 15;
break;
default:
v->now--; /* oops, not a digit at all */
d = -1;
break;
}
if (d >= base)
{ /* not a plausible digit */
v->now--;
d = -1;
}
if (d < 0)
break; /* NOTE BREAK OUT */
n = n * ub + (uchr) d;
}
if (len < minlen)
ERR(REG_EESCAPE);
return (chr) n;
}
/*
* brenext - get next BRE token
*
* This is much like EREs except for all the stupid backslashes and the
* context-dependency of some things.
*/
static int /* 1 normal, 0 failure */
brenext(struct vars * v,
chr pc)
{
chr c = (chr) pc;
switch (c)
{
case CHR('*'):
if (LASTTYPE(EMPTY) || LASTTYPE('(') || LASTTYPE('^'))
RETV(PLAIN, c);
RET('*');
break;
case CHR('['):
if (HAVE(6) && *(v->now + 0) == CHR('[') &&
*(v->now + 1) == CHR(':') &&
(*(v->now + 2) == CHR('<') ||
*(v->now + 2) == CHR('>')) &&
*(v->now + 3) == CHR(':') &&
*(v->now + 4) == CHR(']') &&
*(v->now + 5) == CHR(']'))
{
c = *(v->now + 2);
v->now += 6;
NOTE(REG_UNONPOSIX);
RET((c == CHR('<')) ? '<' : '>');
}
INTOCON(L_BRACK);
if (NEXT1('^'))
{
v->now++;
RETV('[', 0);
}
RETV('[', 1);
break;
case CHR('.'):
RET('.');
break;
case CHR('^'):
if (LASTTYPE(EMPTY))
RET('^');
if (LASTTYPE('('))
{
NOTE(REG_UUNSPEC);
RET('^');
}
RETV(PLAIN, c);
break;
case CHR('$'):
if (v->cflags & REG_EXPANDED)
skip(v);
if (ATEOS())
RET('$');
if (NEXT2('\\', ')'))
{
NOTE(REG_UUNSPEC);
RET('$');
}
RETV(PLAIN, c);
break;
case CHR('\\'):
break; /* see below */
default:
RETV(PLAIN, c);
break;
}
assert(c == CHR('\\'));
if (ATEOS())
FAILW(REG_EESCAPE);
c = *v->now++;
switch (c)
{
case CHR('{'):
INTOCON(L_BBND);
NOTE(REG_UBOUNDS);
RET('{');
break;
case CHR('('):
RETV('(', 1);
break;
case CHR(')'):
RETV(')', c);
break;
case CHR('<'):
NOTE(REG_UNONPOSIX);
RET('<');
break;
case CHR('>'):
NOTE(REG_UNONPOSIX);
RET('>');
break;
case CHR('1'):
case CHR('2'):
case CHR('3'):
case CHR('4'):
case CHR('5'):
case CHR('6'):
case CHR('7'):
case CHR('8'):
case CHR('9'):
NOTE(REG_UBACKREF);
RETV(BACKREF, (chr) DIGITVAL(c));
break;
default:
if (iscalnum(c))
{
NOTE(REG_UBSALNUM);
NOTE(REG_UUNSPEC);
}
RETV(PLAIN, c);
break;
}
assert(NOTREACHED);
}
/*
* skip - skip white space and comments in expanded form
*/
static void
skip(struct vars * v)
{
chr *start = v->now;
assert(v->cflags & REG_EXPANDED);
for (;;)
{
while (!ATEOS() && iscspace(*v->now))
v->now++;
if (ATEOS() || *v->now != CHR('#'))
break; /* NOTE BREAK OUT */
assert(NEXT1('#'));
while (!ATEOS() && *v->now != CHR('\n'))
v->now++;
/* leave the newline to be picked up by the iscspace loop */
}
if (v->now != start)
NOTE(REG_UNONPOSIX);
}
/*
* newline - return the chr for a newline
*
* This helps confine use of CHR to this source file.
*/
static chr
newline(void)
{
return CHR('\n');
}
/*
* chrnamed - return the chr known by a given (chr string) name
*
* The code is a bit clumsy, but this routine gets only such specialized
* use that it hardly matters.
*/
static chr
chrnamed(struct vars * v,
chr *startp, /* start of name */
chr *endp, /* just past end of name */
chr lastresort) /* what to return if name lookup fails */
{
celt c;
int errsave;
int e;
struct cvec *cv;
errsave = v->err;
v->err = 0;
c = element(v, startp, endp);
e = v->err;
v->err = errsave;
if (e != 0)
return (chr) lastresort;
cv = range(v, c, c, 0);
if (cv->nchrs == 0)
return (chr) lastresort;
return cv->chrs[0];
}
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