OSchip
/
llvm-project
mirror of https://github.com/THU-DSP-LAB/llvm-project.git
13
0
Fork 6
Code Issues Packages Projects Releases Wiki Activity
llvm-project/llvm/lib/Support/regcomp.c

1705 lines
39 KiB
C
Raw Blame History

/*-
* This code is derived from OpenBSD's libc/regex, original license follows:
*
* Copyright (c) 1992, 1993, 1994 Henry Spencer.
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Henry Spencer.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
*
* @(#)regcomp.c 8.5 (Berkeley) 3/20/94
*/
#include <sys/types.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include "regex_impl.h"
#include "regutils.h"
#include "regex2.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
/* character-class table */
static struct cclass {
const char *name;
const char *chars;
const char *multis;
} cclasses[] = {
{ "alnum", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\
0123456789", ""} ,
{ "alpha", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
""} ,
{ "blank", " \t", ""} ,
{ "cntrl", "\007\b\t\n\v\f\r\1\2\3\4\5\6\16\17\20\21\22\23\24\
\25\26\27\30\31\32\33\34\35\36\37\177", ""} ,
{ "digit", "0123456789", ""} ,
{ "graph", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\
0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
""} ,
{ "lower", "abcdefghijklmnopqrstuvwxyz",
""} ,
{ "print", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\
0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~ ",
""} ,
{ "punct", "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
""} ,
{ "space", "\t\n\v\f\r ", ""} ,
{ "upper", "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
""} ,
{ "xdigit", "0123456789ABCDEFabcdef",
""} ,
{ NULL, 0, "" }
};
/* character-name table */
static struct cname {
const char *name;
char code;
} cnames[] = {
{ "NUL", '\0' },
{ "SOH", '\001' },
{ "STX", '\002' },
{ "ETX", '\003' },
{ "EOT", '\004' },
{ "ENQ", '\005' },
{ "ACK", '\006' },
{ "BEL", '\007' },
{ "alert", '\007' },
{ "BS", '\010' },
{ "backspace", '\b' },
{ "HT", '\011' },
{ "tab", '\t' },
{ "LF", '\012' },
{ "newline", '\n' },
{ "VT", '\013' },
{ "vertical-tab", '\v' },
{ "FF", '\014' },
{ "form-feed", '\f' },
{ "CR", '\015' },
{ "carriage-return", '\r' },
{ "SO", '\016' },
{ "SI", '\017' },
{ "DLE", '\020' },
{ "DC1", '\021' },
{ "DC2", '\022' },
{ "DC3", '\023' },
{ "DC4", '\024' },
{ "NAK", '\025' },
{ "SYN", '\026' },
{ "ETB", '\027' },
{ "CAN", '\030' },
{ "EM", '\031' },
{ "SUB", '\032' },
{ "ESC", '\033' },
{ "IS4", '\034' },
{ "FS", '\034' },
{ "IS3", '\035' },
{ "GS", '\035' },
{ "IS2", '\036' },
{ "RS", '\036' },
{ "IS1", '\037' },
{ "US", '\037' },
{ "space", ' ' },
{ "exclamation-mark", '!' },
{ "quotation-mark", '"' },
{ "number-sign", '#' },
{ "dollar-sign", '$' },
{ "percent-sign", '%' },
{ "ampersand", '&' },
{ "apostrophe", '\'' },
{ "left-parenthesis", '(' },
{ "right-parenthesis", ')' },
{ "asterisk", '*' },
{ "plus-sign", '+' },
{ "comma", ',' },
{ "hyphen", '-' },
{ "hyphen-minus", '-' },
{ "period", '.' },
{ "full-stop", '.' },
{ "slash", '/' },
{ "solidus", '/' },
{ "zero", '0' },
{ "one", '1' },
{ "two", '2' },
{ "three", '3' },
{ "four", '4' },
{ "five", '5' },
{ "six", '6' },
{ "seven", '7' },
{ "eight", '8' },
{ "nine", '9' },
{ "colon", ':' },
{ "semicolon", ';' },
{ "less-than-sign", '<' },
{ "equals-sign", '=' },
{ "greater-than-sign", '>' },
{ "question-mark", '?' },
{ "commercial-at", '@' },
{ "left-square-bracket", '[' },
{ "backslash", '\\' },
{ "reverse-solidus", '\\' },
{ "right-square-bracket", ']' },
{ "circumflex", '^' },
{ "circumflex-accent", '^' },
{ "underscore", '_' },
{ "low-line", '_' },
{ "grave-accent", '`' },
{ "left-brace", '{' },
{ "left-curly-bracket", '{' },
{ "vertical-line", '|' },
{ "right-brace", '}' },
{ "right-curly-bracket", '}' },
{ "tilde", '~' },
{ "DEL", '\177' },
{ NULL, 0 }
};
/*
* 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) */
};
static void p_ere(struct parse *, int);
static void p_ere_exp(struct parse *);
static void p_str(struct parse *);
static void p_bre(struct parse *, int, int);
static int p_simp_re(struct parse *, int);
static int p_count(struct parse *);
static void p_bracket(struct parse *);
static void p_b_term(struct parse *, cset *);
static void p_b_cclass(struct parse *, cset *);
static void p_b_eclass(struct parse *, cset *);
static char p_b_symbol(struct parse *);
static char p_b_coll_elem(struct parse *, int);
static char othercase(int);
static void bothcases(struct parse *, int);
static void ordinary(struct parse *, int);
static void nonnewline(struct parse *);
static void repeat(struct parse *, sopno, int, int);
static int seterr(struct parse *, int);
static cset *allocset(struct parse *);
static void freeset(struct parse *, cset *);
static int freezeset(struct parse *, cset *);
static int firstch(struct parse *, cset *);
static int nch(struct parse *, cset *);
static void mcadd(struct parse *, cset *, const char *);
static void mcinvert(struct parse *, cset *);
static void mccase(struct parse *, cset *);
static int isinsets(struct re_guts *, int);
static int samesets(struct re_guts *, int, int);
static void categorize(struct parse *, struct re_guts *);
static sopno dupl(struct parse *, sopno, sopno);
static void doemit(struct parse *, sop, size_t);
static void doinsert(struct parse *, sop, size_t, sopno);
static void dofwd(struct parse *, sopno, sop);
static void enlarge(struct parse *, sopno);
static void stripsnug(struct parse *, struct re_guts *);
static void findmust(struct parse *, struct re_guts *);
static sopno pluscount(struct parse *, struct re_guts *);
static char nuls[10]; /* place to point scanner in event of error */
/*
* 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->end - p->next > 0)
#define MORE2() (p->end - p->next > 1)
#define SEE(c) (MORE() && PEEK() == (c))
#define SEETWO(a, b) (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) (void)((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))
#ifdef _POSIX2_RE_DUP_MAX
#define DUPMAX _POSIX2_RE_DUP_MAX
#else
#define DUPMAX 255
#endif
#define INFINITY (DUPMAX + 1)
#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
/*
- llvm_regcomp - interface for parser and compilation
*/
int /* 0 success, otherwise REG_something */
llvm_regcomp(llvm_regex_t *preg, const char *pattern, int cflags)
{
struct parse pa;
struct re_guts *g;
struct parse *p = &pa;
int i;
size_t len;
#ifdef REDEBUG
# define GOODFLAGS(f) (f)
#else
# define GOODFLAGS(f) ((f)&~REG_DUMP)
#endif
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((const 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 = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */
p->strip = (sop *)calloc(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;
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 llvm_regexec() */
if (g->iflags&REGEX_BAD)
SETERROR(REG_ASSERT);
#endif
/* win or lose, we're done */
if (p->error != 0) /* lose */
llvm_regfree(preg);
return(p->error);
}
/*
- p_ere - ERE parser top level, concatenation and alternation
*/
static void
p_ere(struct parse *p, int stop) /* character this ERE should end at */
{
char c;
sopno prevback = 0;
sopno prevfwd = 0;
sopno conc;
int first = 1; /* is this the first alternative? */
for (;;) {
/* do a bunch of concatenated expressions */
conc = HERE();
while (MORE() && (c = PEEK()) != '|' && c != stop)
p_ere_exp(p);
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(struct parse *p)
{
char c;
sopno pos;
int count;
int count2;
int backrefnum;
sopno subno;
int wascaret = 0;
assert(MORE()); /* caller should have ensured this */
c = GETNEXT();
pos = HERE();
switch (c) {
case '(':
REQUIRE(MORE(), REG_EPAREN);
p->g->nsub++;
subno = 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);
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 '\\':
REQUIRE(MORE(), REG_EESCAPE);
c = GETNEXT();
if (c >= '1' && c <= '9') {
/* \[0-9] is taken to be a back-reference to a previously specified
* matching group. backrefnum will hold the number. The matching
* group must exist (i.e. if \4 is found there must have been at
* least 4 matching groups specified in the pattern previously).
*/
backrefnum = c - '0';
if (p->pend[backrefnum] == 0) {
SETERROR(REG_ESUBREG);
break;
}
/* Make sure everything checks out and emit the sequence
* that marks a back-reference to the parse structure.
*/
assert(backrefnum <= p->g->nsub);
EMIT(OBACK_, backrefnum);
assert(p->pbegin[backrefnum] != 0);
assert(OP(p->strip[p->pbegin[backrefnum]]) != OLPAREN);
assert(OP(p->strip[p->pend[backrefnum]]) != ORPAREN);
(void) dupl(p, p->pbegin[backrefnum]+1, p->pend[backrefnum]);
EMIT(O_BACK, backrefnum);
p->g->backrefs = 1;
} else {
/* Other chars are simply themselves when escaped with a backslash.
*/
ordinary(p, c);
}
break;
case '{': /* okay as ordinary except if digit follows */
REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT);
LLVM_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() && isdigit((uch)PEEK2())) ))
return; /* no repetition, we're done */
NEXT();
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 (isdigit((uch)PEEK())) {
count2 = p_count(p);
REQUIRE(count <= count2, REG_BADBR);
} else /* single number with comma */
count2 = INFINITY;
} else /* just a single number */
count2 = count;
repeat(p, pos, count, count2);
if (!EAT('}')) { /* error heuristics */
while (MORE() && PEEK() != '}')
NEXT();
REQUIRE(MORE(), REG_EBRACE);
SETERROR(REG_BADBR);
}
break;
}
if (!MORE())
return;
c = PEEK();
if (!( c == '*' || c == '+' || c == '?' ||
(c == '{' && MORE2() && isdigit((uch)PEEK2())) ) )
return;
SETERROR(REG_BADRPT);
}
/*
- p_str - string (no metacharacters) "parser"
*/
static void
p_str(struct parse *p)
{
REQUIRE(MORE(), REG_EMPTY);
while (MORE())
ordinary(p, GETNEXT());
}
/*
- p_bre - BRE parser top level, anchoring and concatenation
* 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(struct parse *p,
int end1, /* first terminating character */
int end2) /* second terminating character */
{
sopno start = HERE();
int first = 1; /* first subexpression? */
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++;
}
REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */
}
/*
- p_simp_re - parse a simple RE, an atom possibly followed by a repetition
*/
static int /* was the simple RE an unbackslashed $? */
p_simp_re(struct parse *p,
int starordinary) /* is a leading * an ordinary character? */
{
int c;
int count;
int count2;
sopno pos;
int i;
sopno subno;
# define BACKSL (1<<CHAR_BIT)
pos = HERE(); /* repetition op, if any, covers from here */
assert(MORE()); /* caller should have ensured this */
c = GETNEXT();
if (c == '\\') {
REQUIRE(MORE(), REG_EESCAPE);
c = BACKSL | 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 = 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);
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(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 '*':
REQUIRE(starordinary, REG_BADRPT);
LLVM_FALLTHROUGH;
default:
ordinary(p, (char)c);
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() && isdigit((uch)PEEK())) {
count2 = p_count(p);
REQUIRE(count <= count2, REG_BADBR);
} else /* single number with comma */
count2 = INFINITY;
} else /* just a single number */
count2 = count;
repeat(p, pos, count, count2);
if (!EATTWO('\\', '}')) { /* error heuristics */
while (MORE() && !SEETWO('\\', '}'))
NEXT();
REQUIRE(MORE(), REG_EBRACE);
SETERROR(REG_BADBR);
}
} else if (c == '$') /* $ (but not \$) ends it */
return(1);
return(0);
}
/*
- p_count - parse a repetition count
*/
static int /* the value */
p_count(struct parse *p)
{
int count = 0;
int ndigits = 0;
while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) {
count = count*10 + (GETNEXT() - '0');
ndigits++;
}
REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
return(count);
}
/*
- p_bracket - parse a bracketed character list
*
* Note a significant property of this code: if the allocset() did SETERROR,
* no set operations are done.
*/
static void
p_bracket(struct parse *p)
{
cset *cs;
int invert = 0;
/* Dept of Truly Sickening Special-Case Kludges */
if (p->end - p->next > 5) {
if (strncmp(p->next, "[:<:]]", 6) == 0) {
EMIT(OBOW, 0);
NEXTn(6);
return;
}
if (strncmp(p->next, "[:>:]]", 6) == 0) {
EMIT(OEOW, 0);
NEXTn(6);
return;
}
}
if ((cs = allocset(p)) == NULL) {
/* allocset did set error status in p */
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, '-');
MUSTEAT(']', REG_EBRACK);
if (p->error != 0) { /* don't mess things up further */
freeset(p, cs);
return;
}
if (p->g->cflags&REG_ICASE) {
int i;
int ci;
for (i = p->g->csetsize - 1; i >= 0; i--)
if (CHIN(cs, i) && isalpha(i)) {
ci = othercase(i);
if (ci != i)
CHadd(cs, ci);
}
if (cs->multis != NULL)
mccase(p, cs);
}
if (invert) {
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(struct parse *p, cset *cs)
{
char c;
char start, finish;
int i;
/* classify what we've got */
switch ((MORE()) ? PEEK() : '\0') {
case '[':
c = (MORE2()) ? PEEK2() : '\0';
break;
case '-':
SETERROR(REG_ERANGE);
return; /* NOTE RETURN */
break;
default:
c = '\0';
break;
}
switch (c) {
case ':': /* character class */
NEXT2();
REQUIRE(MORE(), REG_EBRACK);
c = PEEK();
REQUIRE(c != '-' && c != ']', REG_ECTYPE);
p_b_cclass(p, cs);
REQUIRE(MORE(), REG_EBRACK);
REQUIRE(EATTWO(':', ']'), REG_ECTYPE);
break;
case '=': /* equivalence class */
NEXT2();
REQUIRE(MORE(), REG_EBRACK);
c = PEEK();
REQUIRE(c != '-' && c != ']', REG_ECOLLATE);
p_b_eclass(p, cs);
REQUIRE(MORE(), REG_EBRACK);
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... */
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(struct parse *p, cset *cs)
{
char *sp = p->next;
struct cclass *cp;
size_t len;
const char *u;
char c;
while (MORE() && isalpha((uch)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;
}
u = cp->chars;
while ((c = *u++) != '\0')
CHadd(cs, c);
for (u = cp->multis; *u != '\0'; u += strlen(u) + 1)
MCadd(p, cs, u);
}
/*
- p_b_eclass - parse an equivalence-class name and deal with it
*
* This implementation is incomplete. xxx
*/
static void
p_b_eclass(struct parse *p, cset *cs)
{
char c;
c = p_b_coll_elem(p, '=');
CHadd(cs, c);
}
/*
- p_b_symbol - parse a character or [..]ed multicharacter collating symbol
*/
static char /* value of symbol */
p_b_symbol(struct parse *p)
{
char value;
REQUIRE(MORE(), REG_EBRACK);
if (!EATTWO('[', '.'))
return(GETNEXT());
/* collating symbol */
value = p_b_coll_elem(p, '.');
REQUIRE(EATTWO('.', ']'), REG_ECOLLATE);
return(value);
}
/*
- p_b_coll_elem - parse a collating-element name and look it up
*/
static char /* value of collating element */
p_b_coll_elem(struct parse *p,
int endc) /* name ended by endc,']' */
{
char *sp = p->next;
struct cname *cp;
size_t len;
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 && strlen(cp->name) == len)
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 /* if no counterpart, return ch */
othercase(int ch)
{
ch = (uch)ch;
assert(isalpha(ch));
if (isupper(ch))
return ((uch)tolower(ch));
else if (islower(ch))
return ((uch)toupper(ch));
else /* peculiar, but could happen */
return(ch);
}
/*
- bothcases - emit a dualcase version of a two-case character
*
* Boy, is this implementation ever a kludge...
*/
static void
bothcases(struct parse *p, int ch)
{
char *oldnext = p->next;
char *oldend = p->end;
char bracket[3];
ch = (uch)ch;
assert(othercase(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(struct parse *p, int ch)
{
cat_t *cap = p->g->categories;
if ((p->g->cflags&REG_ICASE) && isalpha((uch)ch) && othercase(ch) != ch)
bothcases(p, ch);
else {
EMIT(OCHAR, (uch)ch);
if (cap[ch] == 0)
cap[ch] = p->g->ncategories++;
}
}
/*
- nonnewline - emit REG_NEWLINE version of OANY
*
* Boy, is this implementation ever a kludge...
*/
static void
nonnewline(struct parse *p)
{
char *oldnext = p->next;
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(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 INFINITY) */
{
sopno finish = HERE();
# define N 2
# define INF 3
# define REP(f, t) ((f)*8 + (t))
# define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
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 /* useless but makes type checking happy */
seterr(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(struct parse *p)
{
int no = p->g->ncsets++;
size_t nc;
size_t nbytes;
cset *cs;
size_t css = (size_t)p->g->csetsize;
int i;
if (no >= p->ncsalloc) { /* need another column of space */
void *ptr;
p->ncsalloc += CHAR_BIT;
nc = p->ncsalloc;
if (nc > SIZE_MAX / sizeof(cset))
goto nomem;
assert(nc % CHAR_BIT == 0);
nbytes = nc / CHAR_BIT * css;
ptr = (cset *)realloc((char *)p->g->sets, nc * sizeof(cset));
if (ptr == NULL)
goto nomem;
p->g->sets = ptr;
ptr = (uch *)realloc((char *)p->g->setbits, nbytes);
if (ptr == NULL)
goto nomem;
p->g->setbits = ptr;
for (i = 0; i < no; i++)
p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
(void) memset((char *)p->g->setbits + (nbytes - css), 0, css);
}
/* XXX should not happen */
if (p->g->sets == NULL || p->g->setbits == NULL)
goto nomem;
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);
nomem:
free(p->g->sets);
p->g->sets = NULL;
free(p->g->setbits);
p->g->setbits = NULL;
SETERROR(REG_ESPACE);
/* caller's responsibility not to do set ops */
return(NULL);
}
/*
- freeset - free a now-unused set
*/
static void
freeset(struct parse *p, cset *cs)
{
size_t i;
cset *top = &p->g->sets[p->g->ncsets];
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
*
* 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(struct parse *p, cset *cs)
{
uch h = cs->hash;
size_t i;
cset *top = &p->g->sets[p->g->ncsets];
cset *cs2;
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 /* character; there is no "none" value */
firstch(struct parse *p, cset *cs)
{
size_t i;
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(struct parse *p, cset *cs)
{
size_t i;
size_t css = (size_t)p->g->csetsize;
int n = 0;
for (i = 0; i < css; i++)
if (CHIN(cs, i))
n++;
return(n);
}
/*
- mcadd - add a collating element to a cset
*/
static void
mcadd( struct parse *p, cset *cs, const char *cp)
{
size_t oldend = cs->smultis;
void *np;
cs->smultis += strlen(cp) + 1;
np = realloc(cs->multis, cs->smultis);
if (np == NULL) {
if (cs->multis)
free(cs->multis);
cs->multis = NULL;
SETERROR(REG_ESPACE);
return;
}
cs->multis = np;
llvm_strlcpy(cs->multis + oldend - 1, cp, cs->smultis - oldend + 1);
}
/*
- mcinvert - invert the list of collating elements in a cset
*
* This would have to know the set of possibilities. Implementation
* is deferred.
*/
/* ARGSUSED */
static void
mcinvert(struct parse *p, cset *cs)
{
assert(cs->multis == NULL); /* xxx */
}
/*
- mccase - add case counterparts of the list of collating elements in a cset
*
* This would have to know the set of possibilities. Implementation
* is deferred.
*/
/* ARGSUSED */
static void
mccase(struct parse *p, cset *cs)
{
assert(cs->multis == NULL); /* xxx */
}
/*
- isinsets - is this character in any sets?
*/
static int /* predicate */
isinsets(struct re_guts *g, int c)
{
uch *col;
int i;
int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
unsigned uc = (uch)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 /* predicate */
samesets(struct re_guts *g, int c1, int c2)
{
uch *col;
int i;
int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
unsigned uc1 = (uch)c1;
unsigned uc2 = (uch)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, struct re_guts *g)
{
cat_t *cats = g->categories;
int c;
int c2;
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 /* start of duplicate */
dupl(struct parse *p,
sopno start, /* from here */
sopno finish) /* to this less one */
{
sopno ret = HERE();
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) memmove((char *)(p->strip + p->slen),
(char *)(p->strip + start), (size_t)len*sizeof(sop));
p->slen += len;
return(ret);
}
/*
- doemit - emit a strip operator
*
* 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(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(struct parse *p, sop op, size_t opnd, sopno pos)
{
sopno sn;
sop s;
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]++;
}
}
memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
(HERE()-pos-1)*sizeof(sop));
p->strip[pos] = s;
}
/*
- dofwd - complete a forward reference
*/
static void
dofwd(struct parse *p, 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(struct parse *p, sopno size)
{
sop *sp;
if (p->ssize >= size)
return;
if ((uintptr_t)size > SIZE_MAX / sizeof(sop)) {
SETERROR(REG_ESPACE);
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(struct parse *p, struct re_guts *g)
{
g->nstates = p->slen;
if ((uintptr_t)p->slen > SIZE_MAX / sizeof(sop)) {
g->strip = p->strip;
SETERROR(REG_ESPACE);
return;
}
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
*
* 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(struct parse *p, struct re_guts *g)
{
sop *scan;
sop *start = 0; /* start initialized in the default case, after that */
sop *newstart = 0; /* newstart was initialized in the OCHAR case */
sopno newlen;
sop s;
char *cp;
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 |= REGEX_BAD;
return;
}
} while (OP(s) != O_QUEST && OP(s) != O_CH);
LLVM_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 /* nesting depth */
pluscount(struct parse *p, struct re_guts *g)
{
sop *scan;
sop s;
sopno plusnest = 0;
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 |= REGEX_BAD;
return(maxnest);
}
Reference in New Issue View Git Blame Copy Permalink