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//
// regcomp.c
//
// Compiler for regular expression library
//
// Ported to sanos by Michael Ringgaard.
//
// Copyright 1992, 1993, 1994, 1997 Henry Spencer. All rights reserved.
// This software is not subject to any license of the American Telephone
// and Telegraph Company or of the Regents of the University of California.
//
// Permission is granted to anyone to use this software for any purpose on
// any computer system, and to alter it and redistribute it, subject
// to the following restrictions:
//
// 1. The author is not responsible for the consequences of use of this
// software, no matter how awful, even if they arise from flaws in it.
//
// 2. The origin of this software must not be misrepresented, either by
// explicit claim or by omission. Since few users ever read sources,
// credits must appear in the documentation.
//
// 3. Altered versions must be plainly marked as such, and must not be
// misrepresented as being the original software. Since few users
// ever read sources, credits must appear in the documentation.
//
// 4. This notice may not be removed or altered.
//
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include <regex.h>
#include "regex2.h"
#include "cclass.h"
#include "cname.h"
#ifdef _MSC_VER
#pragma warning(disable: 4018)
#endif
//
// Parse structure, passed up and down to avoid global variables and
// other clumsinesses.
//
#define NPAREN 10
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; // Mumber of csets allocated
struct re_guts *g;
// 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 *p, int stop);
static void p_ere_exp(struct parse *p);
static void p_str(struct parse *p);
static void p_bre(struct parse *p, int end1, int end2);
static int p_simp_re(struct parse *p, int starordinary);
static int p_count(struct parse *p);
static void p_bracket(struct parse *p);
static void p_b_term(struct parse *p, cset *cs);
static void p_b_cclass(struct parse *p, cset *cs);
static void p_b_eclass(struct parse *p, cset *cs);
static char p_b_symbol(struct parse *p);
static char p_b_coll_elem(struct parse *p, int endc);
static char othercase(int ch);
static void bothcases(struct parse *p, int ch);
static void ordinary(struct parse *p, int ch);
static void nonnewline(struct parse *p);
static void repeat(struct parse *p, sopno start, int from, int to);
static int seterr(struct parse *p, int e);
static cset *allocset(struct parse *p);
static void freeset(struct parse *p, cset *cs);
static int freezeset(struct parse *p, cset *cs);
static int firstch(struct parse *p, cset *cs);
static int nch(struct parse *p, cset *cs);
static void mcadd(struct parse *p, cset *cs, char *cp);
static void mcsub(cset *cs, char *cp);
static int mcin(cset *cs, char *cp);
static char *mcfind(cset *cs, char *cp);
static void mcinvert(struct parse *p, cset *cs);
static void mccase(struct parse *p, cset *cs);
static int isinsets(struct re_guts *g, int c);
static int samesets(struct re_guts *g, int c1, int c2);
static void categorize(struct parse *p, struct re_guts *g);
static sopno dupl(struct parse *p, sopno start, sopno finish);
static void doemit(struct parse *p, sop op, size_t opnd);
static void doinsert(struct parse *p, sop op, size_t opnd, sopno pos);
static void dofwd(struct parse *p, sopno pos, sop value);
static void enlarge(struct parse *p, sopno size);
static void stripsnug(struct parse *p, struct re_guts *g);
static void findmust(struct parse *p, struct re_guts *g);
static sopno pluscount(struct parse *p, struct re_guts *g);
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->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
#ifdef REDEBUG
#define GOODFLAGS(f) (f)
#else
#define GOODFLAGS(f) ((f) & ~REG_DUMP)
#endif
//
// regcomp - interface for parser and compilation
//
// Returns 0 on success, otherwise REG_something
//
int regcomp(regex_t *preg, const char *pattern, int cflags) {
struct parse pa;
struct re_guts *g;
struct parse *p = &pa;
int i;
size_t len;
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(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 / 2* 3 + 1; // ugh
p->strip = (sop *) malloc(p->ssize * sizeof(sop));
p->slen = 0;
if (p->strip == NULL) {
free(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)];
memset(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) regfree(preg); // lose
return p->error;
}
//
// p_ere - ERE parser top level, concatenation and alternation
//
static void p_ere(struct parse *p, int stop) {
char c;
sopno prevback;
sopno prevfwd;
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;
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®_NEWLINE)
nonnewline(p);
else
EMIT(OANY, 0);
break;
case '[':
p_bracket(p);
break;
case '\\':
REQUIRE(MORE(), REG_EESCAPE);
c = GETNEXT();
ordinary(p, c);
break;
case '{': // Okay as ordinary except if digit follows
REQUIRE(!MORE() || !isdigit(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() && isdigit(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(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(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, int end2) {
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) {
// Ops, 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
//
#define BACKSL (1 << CHAR_BIT)
static int p_simp_re(struct parse *p, int starordinary) {
int c;
int count;
int count2;
sopno pos;
int i;
sopno subno;
pos = HERE(); // Repetion op, if any, covers from here
assert(MORE()); // Caller should have ensured this
c = GETNEXT();
if (c == '\\') {
REQUIRE(MORE(), REG_EESCAPE);
c = BACKSL | (unsigned char) GETNEXT();
}
switch (c) {
case '.':
if (p->g->cflags®_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);
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);
// FALLTHROUGH
default:
ordinary(p, (char) c); // Takes off BACKSL, if any
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(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 == (unsigned char)'$') {
// $ (but not \$) ends it
return 1;
}
return 0;
}
//
// p_count - parse a repetition count
//
static int p_count(struct parse *p) {
int count = 0;
int ndigits = 0;
while (MORE() && isdigit(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 = allocset(p);
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, '-');
MUSTEAT(']', REG_EBRACK);
if (p->error != 0) return; // Don't mess things up further
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((uch) start <= (uch) finish, REG_ERANGE);
for (i = (uch) start; i <= (uch) 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;
char *u;
char c;
while (MORE() && isalpha(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 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 p_b_coll_elem(struct parse *p, int endc) {
char *sp = p->next;
struct cname *cp;
int 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 && 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) {
assert(isalpha(ch));
if (isupper(ch)) {
return tolower(ch);
} else if (islower(ch)) {
return 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];
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(ch) && othercase(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
//
// 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
//
#define N 2
#define INF 3
#define REP(f, t) ((f) * 8 + (t))
#define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
static void repeat(struct parse *p, sopno start, int from, int to) {
sopno finish = HERE();
sopno copy;
if (p->error != 0) return; // Head off possible runaway recursion
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(struct parse *p, int e) {
if (p->error == 0)p->error = e; // keep earliest error condition
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
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(p->g->sets, nc * sizeof(cset));
}
if (p->g->setbits == NULL) {
p->g->setbits = (uch *) malloc(nbytes);
} else {
p->g->setbits = (uch *) realloc(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) {
memset(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(struct parse *p, cset *cs) {
int 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) p->g->ncsets--; // recover only the easy case
}
//
// 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 freezeset(struct parse *p, cset *cs) {
uch h = cs->hash;
int 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 cs - p->g->sets;
}
//
// firstch - return first character in a set (which must have at least one)
//
static int firstch(struct parse *p, cset *cs) {
int 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) {
int 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, char *cp) {
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;
}
strcpy(cs->multis + oldend - 1, cp);
cs->multis[cs->smultis - 1] = '\0';
}
//
// mcsub - subtract a collating element from a cset
//
static void mcsub(cset *cs, char *cp) {
char *fp = mcfind(cs, cp);
size_t len = strlen(fp);
assert(fp != NULL);
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(cset *cs, char *cp) {
return mcfind(cs, cp) != NULL;
}
//
// mcfind - find a collating element in a cset
//
static char *mcfind(cset *cs, char *cp) {
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;
}
//
// mcinvert - invert the list of collating elements in a cset
//
// This would have to know the set of possibilities. Implementation
// is deferred.
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.
static void mccase(struct parse *p, cset *cs) {
assert(cs->multis == NULL); // xxx
}
//
// isinsets - is this character in any sets?
//
static int isinsets(struct re_guts *g, int c) {
uch *col;
int i;
int ncols = (g->ncsets + (CHAR_BIT - 1)) / CHAR_BIT;
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(struct re_guts *g, int c1, int c2) {
uch *col;
int i;
int ncols = (g->ncsets + (CHAR_BIT - 1)) / CHAR_BIT;
unsigned uc1 = (unsigned char) c1;
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, 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 dupl(struct parse *p, sopno start, sopno finish) {
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);
memcpy(p->strip + p->slen, p->strip + start, 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(&p->strip[pos + 1], &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;
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;
g->strip = (sop *) realloc(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;
sop *newstart;
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) newstart = scan - 1; // new sequence
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) return; // there isn't one
// 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(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 |= BAD;
return maxnest;
}