/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ Copyright (C) Lucent Technologies 1997 │
│ All Rights Reserved │
│ │
│ Permission to use, copy, modify, and distribute this software and │
│ its documentation for any purpose and without fee is hereby │
│ granted, provided that the above copyright notice appear in all │
│ copies and that both that the copyright notice and this │
│ permission notice and warranty disclaimer appear in supporting │
│ documentation, and that the name Lucent Technologies or any of │
│ its entities not be used in advertising or publicity pertaining │
│ to distribution of the software without specific, written prior │
│ permission. │
│ │
│ LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, │
│ INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. │
│ IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY │
│ SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES │
│ WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER │
│ IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, │
│ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF │
│ THIS SOFTWARE. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#define DEBUG
#include "libc/calls/calls.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "third_party/awk/awk.h"
#include "third_party/awk/awkgram.tab.h"
// clang-format off
/* lasciate ogne speranza, voi ch'intrate. */
#define MAXLIN 22
#define type(v) (v)->nobj /* badly overloaded here */
#define info(v) (v)->ntype /* badly overloaded here */
#define left(v) (v)->narg[0]
#define right(v) (v)->narg[1]
#define parent(v) (v)->nnext
#define LEAF case CCL: case NCCL: case CHAR: case DOT: case FINAL: case ALL:
#define ELEAF case EMPTYRE: /* empty string in regexp */
#define UNARY case STAR: case PLUS: case QUEST:
/* encoding in tree Nodes:
leaf (CCL, NCCL, CHAR, DOT, FINAL, ALL, EMPTYRE):
left is index, right contains value or pointer to value
unary (STAR, PLUS, QUEST): left is child, right is null
binary (CAT, OR): left and right are children
parent contains pointer to parent
*/
int *setvec;
int *tmpset;
int maxsetvec = 0;
int rtok; /* next token in current re */
int rlxval;
static const uschar *rlxstr;
static const uschar *prestr; /* current position in current re */
static const uschar *lastre; /* origin of last re */
static const uschar *lastatom; /* origin of last Atom */
static const uschar *starttok;
static const uschar *basestr; /* starts with original, replaced during
repetition processing */
static const uschar *firstbasestr;
static int setcnt;
static int poscnt;
const char *patbeg;
int patlen;
#define NFA 128 /* cache this many dynamic fa's */
fa *fatab[NFA];
int nfatab = 0; /* entries in fatab */
static int *
intalloc(size_t n, const char *f)
{
int *p = (int *) calloc(n, sizeof(int));
if (p == NULL)
overflo(f);
return p;
}
static void
resizesetvec(const char *f)
{
if (maxsetvec == 0)
maxsetvec = MAXLIN;
else
maxsetvec *= 4;
setvec = (int *) realloc(setvec, maxsetvec * sizeof(*setvec));
tmpset = (int *) realloc(tmpset, maxsetvec * sizeof(*tmpset));
if (setvec == NULL || tmpset == NULL)
overflo(f);
}
static void
resize_state(fa *f, int state)
{
unsigned int **p;
uschar *p2;
int **p3;
int i, new_count;
if (++state < f->state_count)
return;
new_count = state + 10; /* needs to be tuned */
p = (unsigned int **) realloc(f->gototab, new_count * sizeof(f->gototab[0]));
if (p == NULL)
goto out;
f->gototab = p;
p2 = (uschar *) realloc(f->out, new_count * sizeof(f->out[0]));
if (p2 == NULL)
goto out;
f->out = p2;
p3 = (int **) realloc(f->posns, new_count * sizeof(f->posns[0]));
if (p3 == NULL)
goto out;
f->posns = p3;
for (i = f->state_count; i < new_count; ++i) {
f->gototab[i] = (unsigned int *) calloc(NCHARS, sizeof(**f->gototab));
if (f->gototab[i] == NULL)
goto out;
f->out[i] = 0;
f->posns[i] = NULL;
}
f->state_count = new_count;
return;
out:
overflo(__func__);
}
fa *makedfa(const char *s, bool anchor) /* returns dfa for reg expr s */
{
int i, use, nuse;
fa *pfa;
static int now = 1;
if (setvec == NULL) { /* first time through any RE */
resizesetvec(__func__);
}
if (compile_time != RUNNING) /* a constant for sure */
return mkdfa(s, anchor);
for (i = 0; i < nfatab; i++) /* is it there already? */
if (fatab[i]->anchor == anchor
&& strcmp((const char *) fatab[i]->restr, s) == 0) {
fatab[i]->use = now++;
return fatab[i];
}
pfa = mkdfa(s, anchor);
if (nfatab < NFA) { /* room for another */
fatab[nfatab] = pfa;
fatab[nfatab]->use = now++;
nfatab++;
return pfa;
}
use = fatab[0]->use; /* replace least-recently used */
nuse = 0;
for (i = 1; i < nfatab; i++)
if (fatab[i]->use < use) {
use = fatab[i]->use;
nuse = i;
}
freefa(fatab[nuse]);
fatab[nuse] = pfa;
pfa->use = now++;
return pfa;
}
fa *mkdfa(const char *s, bool anchor) /* does the real work of making a dfa */
/* anchor = true for anchored matches, else false */
{
Node *p, *p1;
fa *f;
firstbasestr = (const uschar *) s;
basestr = firstbasestr;
p = reparse(s);
p1 = op2(CAT, op2(STAR, op2(ALL, NIL, NIL), NIL), p);
/* put ALL STAR in front of reg. exp. */
p1 = op2(CAT, p1, op2(FINAL, NIL, NIL));
/* put FINAL after reg. exp. */
poscnt = 0;
penter(p1); /* enter parent pointers and leaf indices */
if ((f = (fa *) calloc(1, sizeof(fa) + poscnt * sizeof(rrow))) == NULL)
overflo(__func__);
f->accept = poscnt-1; /* penter has computed number of positions in re */
cfoll(f, p1); /* set up follow sets */
freetr(p1);
resize_state(f, 1);
f->posns[0] = intalloc(*(f->re[0].lfollow), __func__);
f->posns[1] = intalloc(1, __func__);
*f->posns[1] = 0;
f->initstat = makeinit(f, anchor);
f->anchor = anchor;
f->restr = (uschar *) tostring(s);
if (firstbasestr != basestr) {
if (basestr)
xfree(basestr);
}
return f;
}
int makeinit(fa *f, bool anchor)
{
int i, k;
f->curstat = 2;
f->out[2] = 0;
k = *(f->re[0].lfollow);
xfree(f->posns[2]);
f->posns[2] = intalloc(k + 1, __func__);
for (i = 0; i <= k; i++) {
(f->posns[2])[i] = (f->re[0].lfollow)[i];
}
if ((f->posns[2])[1] == f->accept)
f->out[2] = 1;
for (i = 0; i < NCHARS; i++)
f->gototab[2][i] = 0;
f->curstat = cgoto(f, 2, HAT);
if (anchor) {
*f->posns[2] = k-1; /* leave out position 0 */
for (i = 0; i < k; i++) {
(f->posns[0])[i] = (f->posns[2])[i];
}
f->out[0] = f->out[2];
if (f->curstat != 2)
--(*f->posns[f->curstat]);
}
return f->curstat;
}
void penter(Node *p) /* set up parent pointers and leaf indices */
{
switch (type(p)) {
ELEAF
LEAF
info(p) = poscnt;
poscnt++;
break;
UNARY
penter(left(p));
parent(left(p)) = p;
break;
case CAT:
case OR:
penter(left(p));
penter(right(p));
parent(left(p)) = p;
parent(right(p)) = p;
break;
case ZERO:
break;
default: /* can't happen */
FATAL("can't happen: unknown type %d in penter", type(p));
break;
}
}
void freetr(Node *p) /* free parse tree */
{
switch (type(p)) {
ELEAF
LEAF
xfree(p);
break;
UNARY
case ZERO:
freetr(left(p));
xfree(p);
break;
case CAT:
case OR:
freetr(left(p));
freetr(right(p));
xfree(p);
break;
default: /* can't happen */
FATAL("can't happen: unknown type %d in freetr", type(p));
break;
}
}
/* in the parsing of regular expressions, metacharacters like . have */
/* to be seen literally; \056 is not a metacharacter. */
int hexstr(const uschar **pp) /* find and eval hex string at pp, return new p */
{ /* only pick up one 8-bit byte (2 chars) */
const uschar *p;
int n = 0;
int i;
for (i = 0, p = *pp; i < 2 && isxdigit(*p); i++, p++) {
if (isdigit(*p))
n = 16 * n + *p - '0';
else if (*p >= 'a' && *p <= 'f')
n = 16 * n + *p - 'a' + 10;
else if (*p >= 'A' && *p <= 'F')
n = 16 * n + *p - 'A' + 10;
}
*pp = p;
return n;
}
#define isoctdigit(c) ((c) >= '0' && (c) <= '7') /* multiple use of arg */
int quoted(const uschar **pp) /* pick up next thing after a \\ */
/* and increment *pp */
{
const uschar *p = *pp;
int c;
if ((c = *p++) == 't')
c = '\t';
else if (c == 'n')
c = '\n';
else if (c == 'f')
c = '\f';
else if (c == 'r')
c = '\r';
else if (c == 'b')
c = '\b';
else if (c == 'v')
c = '\v';
else if (c == 'a')
c = '\a';
else if (c == '\\')
c = '\\';
else if (c == 'x') { /* hexadecimal goo follows */
c = hexstr(&p); /* this adds a null if number is invalid */
} else if (isoctdigit(c)) { /* \d \dd \ddd */
int n = c - '0';
if (isoctdigit(*p)) {
n = 8 * n + *p++ - '0';
if (isoctdigit(*p))
n = 8 * n + *p++ - '0';
}
c = n;
} /* else */
/* c = c; */
*pp = p;
return c;
}
char *cclenter(const char *argp) /* add a character class */
{
int i, c, c2;
const uschar *op, *p = (const uschar *) argp;
uschar *bp;
static uschar *buf = NULL;
static int bufsz = 100;
op = p;
if (buf == NULL && (buf = (uschar *) malloc(bufsz)) == NULL)
FATAL("out of space for character class [%.10s...] 1", p);
bp = buf;
for (i = 0; (c = *p++) != 0; ) {
if (c == '\\') {
c = quoted(&p);
} else if (c == '-' && i > 0 && bp[-1] != 0) {
if (*p != 0) {
c = bp[-1];
c2 = *p++;
if (c2 == '\\')
c2 = quoted(&p);
if (c > c2) { /* empty; ignore */
bp--;
i--;
continue;
}
while (c < c2) {
if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, "cclenter1"))
FATAL("out of space for character class [%.10s...] 2", p);
*bp++ = ++c;
i++;
}
continue;
}
}
if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, "cclenter2"))
FATAL("out of space for character class [%.10s...] 3", p);
*bp++ = c;
i++;
}
*bp = 0;
DPRINTF("cclenter: in = |%s|, out = |%s|\n", op, buf);
xfree(op);
return (char *) tostring((char *) buf);
}
void overflo(const char *s)
{
FATAL("regular expression too big: out of space in %.30s...", s);
}
void cfoll(fa *f, Node *v) /* enter follow set of each leaf of vertex v into lfollow[leaf] */
{
int i;
int *p;
switch (type(v)) {
ELEAF
LEAF
f->re[info(v)].ltype = type(v);
f->re[info(v)].lval.np = right(v);
while (f->accept >= maxsetvec) { /* guessing here! */
resizesetvec(__func__);
}
for (i = 0; i <= f->accept; i++)
setvec[i] = 0;
setcnt = 0;
follow(v); /* computes setvec and setcnt */
p = intalloc(setcnt + 1, __func__);
f->re[info(v)].lfollow = p;
*p = setcnt;
for (i = f->accept; i >= 0; i--)
if (setvec[i] == 1)
*++p = i;
break;
UNARY
cfoll(f,left(v));
break;
case CAT:
case OR:
cfoll(f,left(v));
cfoll(f,right(v));
break;
case ZERO:
break;
default: /* can't happen */
FATAL("can't happen: unknown type %d in cfoll", type(v));
}
}
int first(Node *p) /* collects initially active leaves of p into setvec */
/* returns 0 if p matches empty string */
{
int b, lp;
switch (type(p)) {
ELEAF
LEAF
lp = info(p); /* look for high-water mark of subscripts */
while (setcnt >= maxsetvec || lp >= maxsetvec) { /* guessing here! */
resizesetvec(__func__);
}
if (type(p) == EMPTYRE) {
setvec[lp] = 0;
return(0);
}
if (setvec[lp] != 1) {
setvec[lp] = 1;
setcnt++;
}
if (type(p) == CCL && (*(char *) right(p)) == '\0')
return(0); /* empty CCL */
return(1);
case PLUS:
if (first(left(p)) == 0)
return(0);
return(1);
case STAR:
case QUEST:
first(left(p));
return(0);
case CAT:
if (first(left(p)) == 0 && first(right(p)) == 0) return(0);
return(1);
case OR:
b = first(right(p));
if (first(left(p)) == 0 || b == 0) return(0);
return(1);
case ZERO:
return 0;
}
FATAL("can't happen: unknown type %d in first", type(p)); /* can't happen */
return(-1);
}
void follow(Node *v) /* collects leaves that can follow v into setvec */
{
Node *p;
if (type(v) == FINAL)
return;
p = parent(v);
switch (type(p)) {
case STAR:
case PLUS:
first(v);
follow(p);
return;
case OR:
case QUEST:
follow(p);
return;
case CAT:
if (v == left(p)) { /* v is left child of p */
if (first(right(p)) == 0) {
follow(p);
return;
}
} else /* v is right child */
follow(p);
return;
}
}
int member(int c, const char *sarg) /* is c in s? */
{
const uschar *s = (const uschar *) sarg;
while (*s)
if (c == *s++)
return(1);
return(0);
}
int match(fa *f, const char *p0) /* shortest match ? */
{
int s, ns;
const uschar *p = (const uschar *) p0;
s = f->initstat;
assert (s < f->state_count);
if (f->out[s])
return(1);
do {
/* assert(*p < NCHARS); */
if ((ns = f->gototab[s][*p]) != 0)
s = ns;
else
s = cgoto(f, s, *p);
if (f->out[s])
return(1);
} while (*p++ != 0);
return(0);
}
int pmatch(fa *f, const char *p0) /* longest match, for sub */
{
int s, ns;
const uschar *p = (const uschar *) p0;
const uschar *q;
s = f->initstat;
assert(s < f->state_count);
patbeg = (const char *)p;
patlen = -1;
do {
q = p;
do {
if (f->out[s]) /* final state */
patlen = q-p;
/* assert(*q < NCHARS); */
if ((ns = f->gototab[s][*q]) != 0)
s = ns;
else
s = cgoto(f, s, *q);
assert(s < f->state_count);
if (s == 1) { /* no transition */
if (patlen >= 0) {
patbeg = (const char *) p;
return(1);
}
else
goto nextin; /* no match */
}
} while (*q++ != 0);
if (f->out[s])
patlen = q-p-1; /* don't count $ */
if (patlen >= 0) {
patbeg = (const char *) p;
return(1);
}
nextin:
s = 2;
} while (*p++);
return (0);
}
int nematch(fa *f, const char *p0) /* non-empty match, for sub */
{
int s, ns;
const uschar *p = (const uschar *) p0;
const uschar *q;
s = f->initstat;
assert(s < f->state_count);
patbeg = (const char *)p;
patlen = -1;
while (*p) {
q = p;
do {
if (f->out[s]) /* final state */
patlen = q-p;
/* assert(*q < NCHARS); */
if ((ns = f->gototab[s][*q]) != 0)
s = ns;
else
s = cgoto(f, s, *q);
if (s == 1) { /* no transition */
if (patlen > 0) {
patbeg = (const char *) p;
return(1);
} else
goto nnextin; /* no nonempty match */
}
} while (*q++ != 0);
if (f->out[s])
patlen = q-p-1; /* don't count $ */
if (patlen > 0 ) {
patbeg = (const char *) p;
return(1);
}
nnextin:
s = 2;
p++;
}
return (0);
}
/*
* NAME
* fnematch
*
* DESCRIPTION
* A stream-fed version of nematch which transfers characters to a
* null-terminated buffer. All characters up to and including the last
* character of the matching text or EOF are placed in the buffer. If
* a match is found, patbeg and patlen are set appropriately.
*
* RETURN VALUES
* false No match found.
* true Match found.
*/
bool fnematch(fa *pfa, FILE *f, char **pbuf, int *pbufsize, int quantum)
{
char *buf = *pbuf;
int bufsize = *pbufsize;
int c, i, j, k, ns, s;
s = pfa->initstat;
patlen = 0;
/*
* All indices relative to buf.
* i <= j <= k <= bufsize
*
* i: origin of active substring
* j: current character
* k: destination of next getc()
*/
i = -1, k = 0;
do {
j = i++;
do {
if (++j == k) {
if (k == bufsize)
if (!adjbuf((char **) &buf, &bufsize, bufsize+1, quantum, 0, "fnematch"))
FATAL("stream '%.30s...' too long", buf);
buf[k++] = (c = getc(f)) != EOF ? c : 0;
}
c = (uschar)buf[j];
/* assert(c < NCHARS); */
if ((ns = pfa->gototab[s][c]) != 0)
s = ns;
else
s = cgoto(pfa, s, c);
if (pfa->out[s]) { /* final state */
patlen = j - i + 1;
if (c == 0) /* don't count $ */
patlen--;
}
} while (buf[j] && s != 1);
s = 2;
} while (buf[i] && !patlen);
/* adjbuf() may have relocated a resized buffer. Inform the world. */
*pbuf = buf;
*pbufsize = bufsize;
if (patlen) {
patbeg = (char *) buf + i;
/*
* Under no circumstances is the last character fed to
* the automaton part of the match. It is EOF's nullbyte,
* or it sent the automaton into a state with no further
* transitions available (s==1), or both. Room for a
* terminating nullbyte is guaranteed.
*
* ungetc any chars after the end of matching text
* (except for EOF's nullbyte, if present) and null
* terminate the buffer.
*/
do
if (buf[--k] && ungetc(buf[k], f) == EOF)
FATAL("unable to ungetc '%c'", buf[k]);
while (k > i + patlen);
buf[k] = '\0';
return true;
}
else
return false;
}
Node *reparse(const char *p) /* parses regular expression pointed to by p */
{ /* uses relex() to scan regular expression */
Node *np;
DPRINTF("reparse <%s>\n", p);
lastre = prestr = (const uschar *) p; /* prestr points to string to be parsed */
rtok = relex();
/* GNU compatibility: an empty regexp matches anything */
if (rtok == '\0') {
/* FATAL("empty regular expression"); previous */
return(op2(EMPTYRE, NIL, NIL));
}
np = regexp();
if (rtok != '\0')
FATAL("syntax error in regular expression %s at %s", lastre, prestr);
return(np);
}
Node *regexp(void) /* top-level parse of reg expr */
{
return (alt(concat(primary())));
}
Node *primary(void)
{
Node *np;
int savelastatom;
switch (rtok) {
case CHAR:
lastatom = starttok;
np = op2(CHAR, NIL, itonp(rlxval));
rtok = relex();
return (unary(np));
case ALL:
rtok = relex();
return (unary(op2(ALL, NIL, NIL)));
case EMPTYRE:
rtok = relex();
return (unary(op2(EMPTYRE, NIL, NIL)));
case DOT:
lastatom = starttok;
rtok = relex();
return (unary(op2(DOT, NIL, NIL)));
case CCL:
np = op2(CCL, NIL, (Node*) cclenter((const char *) rlxstr));
lastatom = starttok;
rtok = relex();
return (unary(np));
case NCCL:
np = op2(NCCL, NIL, (Node *) cclenter((const char *) rlxstr));
lastatom = starttok;
rtok = relex();
return (unary(np));
case '^':
rtok = relex();
return (unary(op2(CHAR, NIL, itonp(HAT))));
case '$':
rtok = relex();
return (unary(op2(CHAR, NIL, NIL)));
case '(':
lastatom = starttok;
savelastatom = starttok - basestr; /* Retain over recursion */
rtok = relex();
if (rtok == ')') { /* special pleading for () */
rtok = relex();
return unary(op2(CCL, NIL, (Node *) tostring("")));
}
np = regexp();
if (rtok == ')') {
lastatom = basestr + savelastatom; /* Restore */
rtok = relex();
return (unary(np));
}
else
FATAL("syntax error in regular expression %s at %s", lastre, prestr);
default:
FATAL("illegal primary in regular expression %s at %s", lastre, prestr);
}
return 0; /*NOTREACHED*/
}
Node *concat(Node *np)
{
switch (rtok) {
case CHAR: case DOT: case ALL: case CCL: case NCCL: case '$': case '(':
return (concat(op2(CAT, np, primary())));
case EMPTYRE:
rtok = relex();
return (concat(op2(CAT, op2(CCL, NIL, (Node *) tostring("")),
primary())));
}
return (np);
}
Node *alt(Node *np)
{
if (rtok == OR) {
rtok = relex();
return (alt(op2(OR, np, concat(primary()))));
}
return (np);
}
Node *unary(Node *np)
{
switch (rtok) {
case STAR:
rtok = relex();
return (unary(op2(STAR, np, NIL)));
case PLUS:
rtok = relex();
return (unary(op2(PLUS, np, NIL)));
case QUEST:
rtok = relex();
return (unary(op2(QUEST, np, NIL)));
case ZERO:
rtok = relex();
return (unary(op2(ZERO, np, NIL)));
default:
return (np);
}
}
/*
* Character class definitions conformant to the POSIX locale as
* defined in IEEE P1003.1 draft 7 of June 2001, assuming the source
* and operating character sets are both ASCII (ISO646) or supersets
* thereof.
*
* Note that to avoid overflowing the temporary buffer used in
* relex(), the expanded character class (prior to range expansion)
* must be less than twice the size of their full name.
*/
static const struct charclass {
const char *cc_name;
int cc_namelen;
int (*cc_func)(int);
} charclasses[] = {
{ "alnum", 5, isalnum },
{ "alpha", 5, isalpha },
{ "blank", 5, isblank },
{ "cntrl", 5, iscntrl },
{ "digit", 5, isdigit },
{ "graph", 5, isgraph },
{ "lower", 5, islower },
{ "print", 5, isprint },
{ "punct", 5, ispunct },
{ "space", 5, isspace },
{ "upper", 5, isupper },
{ "xdigit", 6, isxdigit },
{ NULL, 0, NULL },
};
#define REPEAT_SIMPLE 0
#define REPEAT_PLUS_APPENDED 1
#define REPEAT_WITH_Q 2
#define REPEAT_ZERO 3
static int
replace_repeat(const uschar *reptok, int reptoklen, const uschar *atom,
int atomlen, int firstnum, int secondnum, int special_case)
{
int i, j;
uschar *buf = 0;
int ret = 1;
int init_q = (firstnum == 0); /* first added char will be ? */
int n_q_reps = secondnum-firstnum; /* m>n, so reduce until {1,m-n} left */
int prefix_length = reptok - basestr; /* prefix includes first rep */
int suffix_length = strlen((const char *) reptok) - reptoklen; /* string after rep specifier */
int size = prefix_length + suffix_length;
if (firstnum > 1) { /* add room for reps 2 through firstnum */
size += atomlen*(firstnum-1);
}
/* Adjust size of buffer for special cases */
if (special_case == REPEAT_PLUS_APPENDED) {
size++; /* for the final + */
} else if (special_case == REPEAT_WITH_Q) {
size += init_q + (atomlen+1)* (n_q_reps-init_q);
} else if (special_case == REPEAT_ZERO) {
size += 2; /* just a null ERE: () */
}
if ((buf = (uschar *) malloc(size + 1)) == NULL)
FATAL("out of space in reg expr %.10s..", lastre);
memcpy(buf, basestr, prefix_length); /* copy prefix */
j = prefix_length;
if (special_case == REPEAT_ZERO) {
j -= atomlen;
buf[j++] = '(';
buf[j++] = ')';
}
for (i = 1; i < firstnum; i++) { /* copy x reps */
memcpy(&buf[j], atom, atomlen);
j += atomlen;
}
if (special_case == REPEAT_PLUS_APPENDED) {
buf[j++] = '+';
} else if (special_case == REPEAT_WITH_Q) {
if (init_q)
buf[j++] = '?';
for (i = init_q; i < n_q_reps; i++) { /* copy x? reps */
memcpy(&buf[j], atom, atomlen);
j += atomlen;
buf[j++] = '?';
}
}
memcpy(&buf[j], reptok+reptoklen, suffix_length);
j += suffix_length;
buf[j] = '\0';
/* free old basestr */
if (firstbasestr != basestr) {
if (basestr)
xfree(basestr);
}
basestr = buf;
prestr = buf + prefix_length;
if (special_case == REPEAT_ZERO) {
prestr -= atomlen;
ret++;
}
return ret;
}
static int repeat(const uschar *reptok, int reptoklen, const uschar *atom,
int atomlen, int firstnum, int secondnum)
{
/*
In general, the repetition specifier or "bound" is replaced here
by an equivalent ERE string, repeating the immediately previous atom
and appending ? and + as needed. Note that the first copy of the
atom is left in place, except in the special_case of a zero-repeat
(i.e., {0}).
*/
if (secondnum < 0) { /* means {n,} -> repeat n-1 times followed by PLUS */
if (firstnum < 2) {
/* 0 or 1: should be handled before you get here */
FATAL("internal error");
} else {
return replace_repeat(reptok, reptoklen, atom, atomlen,
firstnum, secondnum, REPEAT_PLUS_APPENDED);
}
} else if (firstnum == secondnum) { /* {n} or {n,n} -> simply repeat n-1 times */
if (firstnum == 0) { /* {0} or {0,0} */
/* This case is unusual because the resulting
replacement string might actually be SMALLER than
the original ERE */
return replace_repeat(reptok, reptoklen, atom, atomlen,
firstnum, secondnum, REPEAT_ZERO);
} else { /* (firstnum >= 1) */
return replace_repeat(reptok, reptoklen, atom, atomlen,
firstnum, secondnum, REPEAT_SIMPLE);
}
} else if (firstnum < secondnum) { /* {n,m} -> repeat n-1 times then alternate */
/* x{n,m} => xx...x{1, m-n+1} => xx...x?x?x?..x? */
return replace_repeat(reptok, reptoklen, atom, atomlen,
firstnum, secondnum, REPEAT_WITH_Q);
} else { /* Error - shouldn't be here (n>m) */
FATAL("internal error");
}
return 0;
}
int relex(void) /* lexical analyzer for reparse */
{
int c, n;
int cflag;
static uschar *buf = NULL;
static int bufsz = 100;
uschar *bp;
const struct charclass *cc;
int i;
int num, m;
bool commafound, digitfound;
const uschar *startreptok;
static int parens = 0;
rescan:
starttok = prestr;
switch (c = *prestr++) {
case '|': return OR;
case '*': return STAR;
case '+': return PLUS;
case '?': return QUEST;
case '.': return DOT;
case '\0': prestr--; return '\0';
case '^':
case '$':
return c;
case '(':
parens++;
return c;
case ')':
if (parens) {
parens--;
return c;
}
/* unmatched close parenthesis; per POSIX, treat as literal */
rlxval = c;
return CHAR;
case '\\':
rlxval = quoted(&prestr);
return CHAR;
default:
rlxval = c;
return CHAR;
case '[':
if (buf == NULL && (buf = (uschar *) malloc(bufsz)) == NULL)
FATAL("out of space in reg expr %.10s..", lastre);
bp = buf;
if (*prestr == '^') {
cflag = 1;
prestr++;
}
else
cflag = 0;
n = 2 * strlen((const char *) prestr)+1;
if (!adjbuf((char **) &buf, &bufsz, n, n, (char **) &bp, "relex1"))
FATAL("out of space for reg expr %.10s...", lastre);
for (; ; ) {
if ((c = *prestr++) == '\\') {
*bp++ = '\\';
if ((c = *prestr++) == '\0')
FATAL("nonterminated character class %.20s...", lastre);
*bp++ = c;
/* } else if (c == '\n') { */
/* FATAL("newline in character class %.20s...", lastre); */
} else if (c == '[' && *prestr == ':') {
/* POSIX char class names, Dag-Erling Smorgrav, des@ofug.org */
for (cc = charclasses; cc->cc_name; cc++)
if (strncmp((const char *) prestr + 1, (const char *) cc->cc_name, cc->cc_namelen) == 0)
break;
if (cc->cc_name != NULL && prestr[1 + cc->cc_namelen] == ':' &&
prestr[2 + cc->cc_namelen] == ']') {
prestr += cc->cc_namelen + 3;
/*
* BUG: We begin at 1, instead of 0, since we
* would otherwise prematurely terminate the
* string for classes like [[:cntrl:]]. This
* means that we can't match the NUL character,
* not without first adapting the entire
* program to track each string's length.
*/
for (i = 1; i <= UCHAR_MAX; i++) {
if (!adjbuf((char **) &buf, &bufsz, bp-buf+2, 100, (char **) &bp, "relex2"))
FATAL("out of space for reg expr %.10s...", lastre);
if (cc->cc_func(i)) {
/* escape backslash */
if (i == '\\') {
*bp++ = '\\';
n++;
}
*bp++ = i;
n++;
}
}
} else
*bp++ = c;
} else if (c == '[' && *prestr == '.') {
char collate_char;
prestr++;
collate_char = *prestr++;
if (*prestr == '.' && prestr[1] == ']') {
prestr += 2;
/* Found it: map via locale TBD: for
now, simply return this char. This
is sufficient to pass conformance
test awk.ex 156
*/
if (*prestr == ']') {
prestr++;
rlxval = collate_char;
return CHAR;
}
}
} else if (c == '[' && *prestr == '=') {
char equiv_char;
prestr++;
equiv_char = *prestr++;
if (*prestr == '=' && prestr[1] == ']') {
prestr += 2;
/* Found it: map via locale TBD: for now
simply return this char. This is
sufficient to pass conformance test
awk.ex 156
*/
if (*prestr == ']') {
prestr++;
rlxval = equiv_char;
return CHAR;
}
}
} else if (c == '\0') {
FATAL("nonterminated character class %.20s", lastre);
} else if (bp == buf) { /* 1st char is special */
*bp++ = c;
} else if (c == ']') {
*bp++ = 0;
rlxstr = (uschar *) tostring((char *) buf);
if (cflag == 0)
return CCL;
else
return NCCL;
} else
*bp++ = c;
}
break;
case '{':
if (isdigit(*(prestr))) {
num = 0; /* Process as a repetition */
n = -1; m = -1;
commafound = false;
digitfound = false;
startreptok = prestr-1;
/* Remember start of previous atom here ? */
} else { /* just a { char, not a repetition */
rlxval = c;
return CHAR;
}
for (; ; ) {
if ((c = *prestr++) == '}') {
if (commafound) {
if (digitfound) { /* {n,m} */
m = num;
if (m < n)
FATAL("illegal repetition expression: class %.20s",
lastre);
if (n == 0 && m == 1) {
return QUEST;
}
} else { /* {n,} */
if (n == 0)
return STAR;
else if (n == 1)
return PLUS;
}
} else {
if (digitfound) { /* {n} same as {n,n} */
n = num;
m = num;
} else { /* {} */
FATAL("illegal repetition expression: class %.20s",
lastre);
}
}
if (repeat(starttok, prestr-starttok, lastatom,
startreptok - lastatom, n, m) > 0) {
if (n == 0 && m == 0) {
return ZERO;
}
/* must rescan input for next token */
goto rescan;
}
/* Failed to replace: eat up {...} characters
and treat like just PLUS */
return PLUS;
} else if (c == '\0') {
FATAL("nonterminated character class %.20s",
lastre);
} else if (isdigit(c)) {
num = 10 * num + c - '0';
digitfound = true;
} else if (c == ',') {
if (commafound)
FATAL("illegal repetition expression: class %.20s",
lastre);
/* looking for {n,} or {n,m} */
commafound = true;
n = num;
digitfound = false; /* reset */
num = 0;
} else {
FATAL("illegal repetition expression: class %.20s",
lastre);
}
}
break;
}
}
int cgoto(fa *f, int s, int c)
{
int *p, *q;
int i, j, k;
assert(c == HAT || c < NCHARS);
while (f->accept >= maxsetvec) { /* guessing here! */
resizesetvec(__func__);
}
for (i = 0; i <= f->accept; i++)
setvec[i] = 0;
setcnt = 0;
resize_state(f, s);
/* compute positions of gototab[s,c] into setvec */
p = f->posns[s];
for (i = 1; i <= *p; i++) {
if ((k = f->re[p[i]].ltype) != FINAL) {
if ((k == CHAR && c == ptoi(f->re[p[i]].lval.np))
|| (k == DOT && c != 0 && c != HAT)
|| (k == ALL && c != 0)
|| (k == EMPTYRE && c != 0)
|| (k == CCL && member(c, (char *) f->re[p[i]].lval.up))
|| (k == NCCL && !member(c, (char *) f->re[p[i]].lval.up) && c != 0 && c != HAT)) {
q = f->re[p[i]].lfollow;
for (j = 1; j <= *q; j++) {
if (q[j] >= maxsetvec) {
resizesetvec(__func__);
}
if (setvec[q[j]] == 0) {
setcnt++;
setvec[q[j]] = 1;
}
}
}
}
}
/* determine if setvec is a previous state */
tmpset[0] = setcnt;
j = 1;
for (i = f->accept; i >= 0; i--)
if (setvec[i]) {
tmpset[j++] = i;
}
resize_state(f, f->curstat > s ? f->curstat : s);
/* tmpset == previous state? */
for (i = 1; i <= f->curstat; i++) {
p = f->posns[i];
if ((k = tmpset[0]) != p[0])
goto different;
for (j = 1; j <= k; j++)
if (tmpset[j] != p[j])
goto different;
/* setvec is state i */
if (c != HAT)
f->gototab[s][c] = i;
return i;
different:;
}
/* add tmpset to current set of states */
++(f->curstat);
resize_state(f, f->curstat);
for (i = 0; i < NCHARS; i++)
f->gototab[f->curstat][i] = 0;
xfree(f->posns[f->curstat]);
p = intalloc(setcnt + 1, __func__);
f->posns[f->curstat] = p;
if (c != HAT)
f->gototab[s][c] = f->curstat;
for (i = 0; i <= setcnt; i++)
p[i] = tmpset[i];
if (setvec[f->accept])
f->out[f->curstat] = 1;
else
f->out[f->curstat] = 0;
return f->curstat;
}
void freefa(fa *f) /* free a finite automaton */
{
int i;
if (f == NULL)
return;
for (i = 0; i < f->state_count; i++)
xfree(f->gototab[i])
for (i = 0; i <= f->curstat; i++)
xfree(f->posns[i]);
for (i = 0; i <= f->accept; i++) {
xfree(f->re[i].lfollow);
if (f->re[i].ltype == CCL || f->re[i].ltype == NCCL)
xfree(f->re[i].lval.np);
}
xfree(f->restr);
xfree(f->out);
xfree(f->posns);
xfree(f->gototab);
xfree(f);
}