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OpenFPGA/libs/EXTERNAL/tcl8.6.12/generic/regcomp.c

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/*
* re_*comp and friends - compile REs
* This file #includes several others (see the bottom).
*
* Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
*
* Development of this software was funded, in part, by Cray Research Inc.,
* UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
* Corporation, none of whom are responsible for the results. The author
* thanks all of them.
*
* Redistribution and use in source and binary forms -- with or without
* modification -- are permitted for any purpose, provided that
* redistributions in source form retain this entire copyright notice and
* indicate the origin and nature of any modifications.
*
* I'd appreciate being given credit for this package in the documentation of
* software which uses it, but that is not a requirement.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "regguts.h"
/*
* forward declarations, up here so forward datatypes etc. are defined early
*/
/* =====^!^===== begin forwards =====^!^===== */
/* automatically gathered by fwd; do not hand-edit */
/* === regcomp.c === */
int compile(regex_t *, const chr *, size_t, int);
static void moresubs(struct vars *, int);
static int freev(struct vars *, int);
static void makesearch(struct vars *, struct nfa *);
static struct subre *parse(struct vars *, int, int, struct state *, struct state *);
static struct subre *parsebranch(struct vars *, int, int, struct state *, struct state *, int);
static void parseqatom(struct vars *, int, int, struct state *, struct state *, struct subre *);
static void nonword(struct vars *, int, struct state *, struct state *);
static void word(struct vars *, int, struct state *, struct state *);
static int scannum(struct vars *);
static void repeat(struct vars *, struct state *, struct state *, int, int);
static void bracket(struct vars *, struct state *, struct state *);
static void cbracket(struct vars *, struct state *, struct state *);
static void brackpart(struct vars *, struct state *, struct state *);
static const chr *scanplain(struct vars *);
static void onechr(struct vars *, pchr, struct state *, struct state *);
static void dovec(struct vars *, struct cvec *, struct state *, struct state *);
static void wordchrs(struct vars *);
static struct subre *subre(struct vars *, int, int, struct state *, struct state *);
static void freesubre(struct vars *, struct subre *);
static void freesrnode(struct vars *, struct subre *);
static int numst(struct subre *, int);
static void markst(struct subre *);
static void cleanst(struct vars *);
static long nfatree(struct vars *, struct subre *, FILE *);
static long nfanode(struct vars *, struct subre *, FILE *);
static int newlacon(struct vars *, struct state *, struct state *, int);
static void freelacons(struct subre *, int);
static void rfree(regex_t *);
static void dump(regex_t *, FILE *);
static void dumpst(struct subre *, FILE *, int);
static void stdump(struct subre *, FILE *, int);
static const char *stid(struct subre *, char *, size_t);
/* === regc_lex.c === */
static void lexstart(struct vars *);
static void prefixes(struct vars *);
static void lexnest(struct vars *, const chr *, const chr *);
static void lexword(struct vars *);
static int next(struct vars *);
static int lexescape(struct vars *);
static int lexdigits(struct vars *, int, int, int);
static int brenext(struct vars *, pchr);
static void skip(struct vars *);
static chr newline(NOPARMS);
static chr chrnamed(struct vars *, const chr *, const chr *, pchr);
/* === regc_color.c === */
static void initcm(struct vars *, struct colormap *);
static void freecm(struct colormap *);
static void cmtreefree(struct colormap *, union tree *, int);
static color setcolor(struct colormap *, pchr, pcolor);
static color maxcolor(struct colormap *);
static color newcolor(struct colormap *);
static void freecolor(struct colormap *, pcolor);
static color pseudocolor(struct colormap *);
static color subcolor(struct colormap *, pchr c);
static color newsub(struct colormap *, pcolor);
static void subrange(struct vars *, pchr, pchr, struct state *, struct state *);
static void subblock(struct vars *, pchr, struct state *, struct state *);
static void okcolors(struct nfa *, struct colormap *);
static void colorchain(struct colormap *, struct arc *);
static void uncolorchain(struct colormap *, struct arc *);
static void rainbow(struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *);
static void colorcomplement(struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *);
#ifdef REG_DEBUG
static void dumpcolors(struct colormap *, FILE *);
static void fillcheck(struct colormap *, union tree *, int, FILE *);
static void dumpchr(pchr, FILE *);
#endif
/* === regc_nfa.c === */
static struct nfa *newnfa(struct vars *, struct colormap *, struct nfa *);
static void freenfa(struct nfa *);
static struct state *newstate(struct nfa *);
static struct state *newfstate(struct nfa *, int flag);
static void dropstate(struct nfa *, struct state *);
static void freestate(struct nfa *, struct state *);
static void destroystate(struct nfa *, struct state *);
static void newarc(struct nfa *, int, pcolor, struct state *, struct state *);
static void createarc(struct nfa *, int, pcolor, struct state *, struct state *);
static struct arc *allocarc(struct nfa *, struct state *);
static void freearc(struct nfa *, struct arc *);
static void changearctarget(struct arc *, struct state *);
static int hasnonemptyout(struct state *);
static struct arc *findarc(struct state *, int, pcolor);
static void cparc(struct nfa *, struct arc *, struct state *, struct state *);
static void sortins(struct nfa *, struct state *);
static int sortins_cmp(const void *, const void *);
static void sortouts(struct nfa *, struct state *);
static int sortouts_cmp(const void *, const void *);
static void moveins(struct nfa *, struct state *, struct state *);
static void copyins(struct nfa *, struct state *, struct state *);
static void mergeins(struct nfa *, struct state *, struct arc **, int);
static void moveouts(struct nfa *, struct state *, struct state *);
static void copyouts(struct nfa *, struct state *, struct state *);
static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int);
static void delsub(struct nfa *, struct state *, struct state *);
static void deltraverse(struct nfa *, struct state *, struct state *);
static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *);
static void duptraverse(struct nfa *, struct state *, struct state *, int);
static void cleartraverse(struct nfa *, struct state *);
static void specialcolors(struct nfa *);
static long optimize(struct nfa *, FILE *);
static void pullback(struct nfa *, FILE *);
static int pull(struct nfa *, struct arc *, struct state **);
static void pushfwd(struct nfa *, FILE *);
static int push(struct nfa *, struct arc *, struct state **);
#define INCOMPATIBLE 1 /* destroys arc */
#define SATISFIED 2 /* constraint satisfied */
#define COMPATIBLE 3 /* compatible but not satisfied yet */
static int combine(struct arc *, struct arc *);
static void fixempties(struct nfa *, FILE *);
static struct state *emptyreachable(struct nfa *, struct state *,
struct state *, struct arc **);
static int isconstraintarc(struct arc *);
static int hasconstraintout(struct state *);
static void fixconstraintloops(struct nfa *, FILE *);
static int findconstraintloop(struct nfa *, struct state *);
static void breakconstraintloop(struct nfa *, struct state *);
static void clonesuccessorstates(struct nfa *, struct state *, struct state *,
struct state *, struct arc *, char *, char *, int);
static void cleanup(struct nfa *);
static void markreachable(struct nfa *, struct state *, struct state *, struct state *);
static void markcanreach(struct nfa *, struct state *, struct state *, struct state *);
static long analyze(struct nfa *);
static void compact(struct nfa *, struct cnfa *);
static void carcsort(struct carc *, size_t);
static int carc_cmp(const void *, const void *);
static void freecnfa(struct cnfa *);
static void dumpnfa(struct nfa *, FILE *);
#ifdef REG_DEBUG
static void dumpstate(struct state *, FILE *);
static void dumparcs(struct state *, FILE *);
static void dumparc(struct arc *, struct state *, FILE *);
#endif
static void dumpcnfa(struct cnfa *, FILE *);
#ifdef REG_DEBUG
static void dumpcstate(int, struct cnfa *, FILE *);
#endif
/* === regc_cvec.c === */
static struct cvec *clearcvec(struct cvec *);
static void addchr(struct cvec *, pchr);
static void addrange(struct cvec *, pchr, pchr);
static struct cvec *newcvec(int, int);
static struct cvec *getcvec(struct vars *, int, int);
static void freecvec(struct cvec *);
/* === regc_locale.c === */
static celt element(struct vars *, const chr *, const chr *);
static struct cvec *range(struct vars *, celt, celt, int);
static int before(celt, celt);
static struct cvec *eclass(struct vars *, celt, int);
static struct cvec *cclass(struct vars *, const chr *, const chr *, int);
static struct cvec *allcases(struct vars *, pchr);
static int cmp(const chr *, const chr *, size_t);
static int casecmp(const chr *, const chr *, size_t);
/* automatically gathered by fwd; do not hand-edit */
/* =====^!^===== end forwards =====^!^===== */
/* internal variables, bundled for easy passing around */
struct vars {
regex_t *re;
const chr *now; /* scan pointer into string */
const chr *stop; /* end of string */
const chr *savenow; /* saved now and stop for "subroutine call" */
const chr *savestop;
int err; /* error code (0 if none) */
int cflags; /* copy of compile flags */
int lasttype; /* type of previous token */
int nexttype; /* type of next token */
chr nextvalue; /* value (if any) of next token */
int lexcon; /* lexical context type (see lex.c) */
int nsubexp; /* subexpression count */
struct subre **subs; /* subRE pointer vector */
size_t nsubs; /* length of vector */
struct subre *sub10[10]; /* initial vector, enough for most */
struct nfa *nfa; /* the NFA */
struct colormap *cm; /* character color map */
color nlcolor; /* color of newline */
struct state *wordchrs; /* state in nfa holding word-char outarcs */
struct subre *tree; /* subexpression tree */
struct subre *treechain; /* all tree nodes allocated */
struct subre *treefree; /* any free tree nodes */
int ntree; /* number of tree nodes, plus one */
struct cvec *cv; /* interface cvec */
struct cvec *cv2; /* utility cvec */
struct subre *lacons; /* lookahead-constraint vector */
int nlacons; /* size of lacons */
size_t spaceused; /* approx. space used for compilation */
};
/* parsing macros; most know that `v' is the struct vars pointer */
#define NEXT() (next(v)) /* advance by one token */
#define SEE(t) (v->nexttype == (t)) /* is next token this? */
#define EAT(t) (SEE(t) && next(v)) /* if next is this, swallow it */
#define VISERR(vv) ((vv)->err != 0)/* have we seen an error yet? */
#define ISERR() VISERR(v)
#define VERR(vv,e) ((vv)->nexttype = EOS, \
(vv)->err = ((vv)->err ? (vv)->err : (e)))
#define ERR(e) VERR(v, e) /* record an error */
#define NOERR() {if (ISERR()) return;} /* if error seen, return */
#define NOERRN() {if (ISERR()) return NULL;} /* NOERR with retval */
#define NOERRZ() {if (ISERR()) return 0;} /* NOERR with retval */
#define INSIST(c, e) do { if (!(c)) ERR(e); } while (0) /* error if c false */
#define NOTE(b) (v->re->re_info |= (b)) /* note visible condition */
#define EMPTYARC(x, y) newarc(v->nfa, EMPTY, 0, x, y)
/* token type codes, some also used as NFA arc types */
#undef DIGIT /* prevent conflict with libtommath */
#define EMPTY 'n' /* no token present */
#define EOS 'e' /* end of string */
#define PLAIN 'p' /* ordinary character */
#define DIGIT 'd' /* digit (in bound) */
#define BACKREF 'b' /* back reference */
#define COLLEL 'I' /* start of [. */
#define ECLASS 'E' /* start of [= */
#define CCLASS 'C' /* start of [: */
#define END 'X' /* end of [. [= [: */
#define RANGE 'R' /* - within [] which might be range delim. */
#define LACON 'L' /* lookahead constraint subRE */
#define AHEAD 'a' /* color-lookahead arc */
#define BEHIND 'r' /* color-lookbehind arc */
#define WBDRY 'w' /* word boundary constraint */
#define NWBDRY 'W' /* non-word-boundary constraint */
#define SBEGIN 'A' /* beginning of string (even if not BOL) */
#define SEND 'Z' /* end of string (even if not EOL) */
#define PREFER 'P' /* length preference */
/* is an arc colored, and hence on a color chain? */
#define COLORED(a) \
((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND)
/* static function list */
static const struct fns functions = {
rfree, /* regfree insides */
};
/*
- compile - compile regular expression
* Note: on failure, no resources remain allocated, so regfree()
* need not be applied to re.
^ int compile(regex_t *, const chr *, size_t, int);
*/
int
compile(
regex_t *re,
const chr *string,
size_t len,
int flags)
{
AllocVars(v);
struct guts *g;
int i;
size_t j;
FILE *debug = (flags&REG_PROGRESS) ? stdout : NULL;
#define CNOERR() { if (ISERR()) return freev(v, v->err); }
/*
* Sanity checks.
*/
if (re == NULL || string == NULL) {
FreeVars(v);
return REG_INVARG;
}
if ((flags&REG_QUOTE) && (flags&(REG_ADVANCED|REG_EXPANDED|REG_NEWLINE))) {
FreeVars(v);
return REG_INVARG;
}
if (!(flags&REG_EXTENDED) && (flags&REG_ADVF)) {
FreeVars(v);
return REG_INVARG;
}
/*
* Initial setup (after which freev() is callable).
*/
v->re = re;
v->now = string;
v->stop = v->now + len;
v->savenow = v->savestop = NULL;
v->err = 0;
v->cflags = flags;
v->nsubexp = 0;
v->subs = v->sub10;
v->nsubs = 10;
for (j = 0; j < v->nsubs; j++) {
v->subs[j] = NULL;
}
v->nfa = NULL;
v->cm = NULL;
v->nlcolor = COLORLESS;
v->wordchrs = NULL;
v->tree = NULL;
v->treechain = NULL;
v->treefree = NULL;
v->cv = NULL;
v->cv2 = NULL;
v->lacons = NULL;
v->nlacons = 0;
v->spaceused = 0;
re->re_magic = REMAGIC;
re->re_info = 0; /* bits get set during parse */
re->re_csize = sizeof(chr);
re->re_guts = NULL;
re->re_fns = (char *)&functions;
/*
* More complex setup, malloced things.
*/
re->re_guts = (char *)(MALLOC(sizeof(struct guts)));
if (re->re_guts == NULL) {
return freev(v, REG_ESPACE);
}
g = (struct guts *) re->re_guts;
g->tree = NULL;
initcm(v, &g->cmap);
v->cm = &g->cmap;
g->lacons = NULL;
g->nlacons = 0;
ZAPCNFA(g->search);
v->nfa = newnfa(v, v->cm, NULL);
CNOERR();
v->cv = newcvec(100, 20);
if (v->cv == NULL) {
return freev(v, REG_ESPACE);
}
/*
* Parsing.
*/
lexstart(v); /* also handles prefixes */
if ((v->cflags&REG_NLSTOP) || (v->cflags&REG_NLANCH)) {
/*
* Assign newline a unique color.
*/
v->nlcolor = subcolor(v->cm, newline());
okcolors(v->nfa, v->cm);
}
CNOERR();
v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
assert(SEE(EOS)); /* even if error; ISERR() => SEE(EOS) */
CNOERR();
assert(v->tree != NULL);
/*
* Finish setup of nfa and its subre tree.
*/
specialcolors(v->nfa);
CNOERR();
if (debug != NULL) {
fprintf(debug, "\n\n\n========= RAW ==========\n");
dumpnfa(v->nfa, debug);
dumpst(v->tree, debug, 1);
}
v->ntree = numst(v->tree, 1);
markst(v->tree);
cleanst(v);
if (debug != NULL) {
fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
dumpst(v->tree, debug, 1);
}
/*
* Build compacted NFAs for tree and lacons.
*/
re->re_info |= nfatree(v, v->tree, debug);
CNOERR();
assert(v->nlacons == 0 || v->lacons != NULL);
for (i = 1; i < v->nlacons; i++) {
if (debug != NULL) {
fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
}
nfanode(v, &v->lacons[i], debug);
}
CNOERR();
if (v->tree->flags&SHORTER) {
NOTE(REG_USHORTEST);
}
/*
* Build compacted NFAs for tree, lacons, fast search.
*/
if (debug != NULL) {
fprintf(debug, "\n\n\n========= SEARCH ==========\n");
}
/*
* Can sacrifice main NFA now, so use it as work area.
*/
(DISCARD) optimize(v->nfa, debug);
CNOERR();
makesearch(v, v->nfa);
CNOERR();
compact(v->nfa, &g->search);
CNOERR();
/*
* Looks okay, package it up.
*/
re->re_nsub = v->nsubexp;
v->re = NULL; /* freev no longer frees re */
g->magic = GUTSMAGIC;
g->cflags = v->cflags;
g->info = re->re_info;
g->nsub = re->re_nsub;
g->tree = v->tree;
v->tree = NULL;
g->ntree = v->ntree;
g->compare = (v->cflags&REG_ICASE) ? casecmp : cmp;
g->lacons = v->lacons;
v->lacons = NULL;
g->nlacons = v->nlacons;
if (flags&REG_DUMP) {
dump(re, stdout);
}
assert(v->err == 0);
return freev(v, 0);
}
/*
- moresubs - enlarge subRE vector
^ static void moresubs(struct vars *, int);
*/
static void
moresubs(
struct vars *v,
int wanted) /* want enough room for this one */
{
struct subre **p;
size_t n;
assert(wanted > 0 && (size_t)wanted >= v->nsubs);
n = (size_t)wanted * 3 / 2 + 1;
if (v->subs == v->sub10) {
p = (struct subre **) MALLOC(n * sizeof(struct subre *));
if (p != NULL) {
memcpy(p, v->subs, v->nsubs * sizeof(struct subre *));
}
} else {
p = (struct subre **) REALLOC(v->subs, n*sizeof(struct subre *));
}
if (p == NULL) {
ERR(REG_ESPACE);
return;
}
v->subs = p;
for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++) {
*p = NULL;
}
assert(v->nsubs == n);
assert((size_t)wanted < v->nsubs);
}
/*
- freev - free vars struct's substructures where necessary
* Optionally does error-number setting, and always returns error code (if
* any), to make error-handling code terser.
^ static int freev(struct vars *, int);
*/
static int
freev(
struct vars *v,
int err)
{
int ret;
if (v->re != NULL) {
rfree(v->re);
}
if (v->subs != v->sub10) {
FREE(v->subs);
}
if (v->nfa != NULL) {
freenfa(v->nfa);
}
if (v->tree != NULL) {
freesubre(v, v->tree);
}
if (v->treechain != NULL) {
cleanst(v);
}
if (v->cv != NULL) {
freecvec(v->cv);
}
if (v->cv2 != NULL) {
freecvec(v->cv2);
}
if (v->lacons != NULL) {
freelacons(v->lacons, v->nlacons);
}
ERR(err); /* nop if err==0 */
ret = v->err;
FreeVars(v);
return ret;
}
/*
- makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
* NFA must have been optimize()d already.
^ static void makesearch(struct vars *, struct nfa *);
*/
static void
makesearch(
struct vars *v,
struct nfa *nfa)
{
struct arc *a, *b;
struct state *pre = nfa->pre;
struct state *s, *s2, *slist;
/*
* No loops are needed if it's anchored.
*/
for (a = pre->outs; a != NULL; a = a->outchain) {
assert(a->type == PLAIN);
if (a->co != nfa->bos[0] && a->co != nfa->bos[1]) {
break;
}
}
if (a != NULL) {
/*
* Add implicit .* in front.
*/
rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);
/*
* And ^* and \A* too -- not always necessary, but harmless.
*/
newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
}
/*
* Now here's the subtle part. Because many REs have no lookback
* constraints, often knowing when you were in the pre state tells you
* little; it's the next state(s) that are informative. But some of them
* may have other inarcs, i.e. it may be possible to make actual progress
* and then return to one of them. We must de-optimize such cases,
* splitting each such state into progress and no-progress states.
*/
/*
* First, make a list of the states.
*/
slist = NULL;
for (a=pre->outs ; a!=NULL ; a=a->outchain) {
s = a->to;
for (b=s->ins ; b!=NULL ; b=b->inchain) {
if (b->from != pre) {
break;
}
}
/*
* We want to mark states as being in the list already by having non
* NULL tmp fields, but we can't just store the old slist value in tmp
* because that doesn't work for the first such state. Instead, the
* first list entry gets its own address in tmp.
*/
if (b != NULL && s->tmp == NULL) {
s->tmp = (slist != NULL) ? slist : s;
slist = s;
}
}
/*
* Do the splits.
*/
for (s=slist ; s!=NULL ; s=s2) {
s2 = newstate(nfa);
NOERR();
copyouts(nfa, s, s2);
NOERR();
for (a=s->ins ; a!=NULL ; a=b) {
b = a->inchain;
if (a->from != pre) {
cparc(nfa, a, a->from, s2);
freearc(nfa, a);
}
}
s2 = (s->tmp != s) ? s->tmp : NULL;
s->tmp = NULL; /* clean up while we're at it */
}
}
/*
- parse - parse an RE
* This is actually just the top level, which parses a bunch of branches tied
* together with '|'. They appear in the tree as the left children of a chain
* of '|' subres.
^ static struct subre *parse(struct vars *, int, int, struct state *,
^ struct state *);
*/
static struct subre *
parse(
struct vars *v,
int stopper, /* EOS or ')' */
int type, /* LACON (lookahead subRE) or PLAIN */
struct state *init, /* initial state */
struct state *final) /* final state */
{
struct state *left, *right; /* scaffolding for branch */
struct subre *branches; /* top level */
struct subre *branch; /* current branch */
struct subre *t; /* temporary */
int firstbranch; /* is this the first branch? */
assert(stopper == ')' || stopper == EOS);
branches = subre(v, '|', LONGER, init, final);
NOERRN();
branch = branches;
firstbranch = 1;
do { /* a branch */
if (!firstbranch) {
/*
* Need a place to hang the branch.
*/
branch->right = subre(v, '|', LONGER, init, final);
NOERRN();
branch = branch->right;
}
firstbranch = 0;
left = newstate(v->nfa);
right = newstate(v->nfa);
NOERRN();
EMPTYARC(init, left);
EMPTYARC(right, final);
NOERRN();
branch->left = parsebranch(v, stopper, type, left, right, 0);
NOERRN();
branch->flags |= UP(branch->flags | branch->left->flags);
if ((branch->flags &~ branches->flags) != 0) { /* new flags */
for (t = branches; t != branch; t = t->right) {
t->flags |= branch->flags;
}
}
} while (EAT('|'));
assert(SEE(stopper) || SEE(EOS));
if (!SEE(stopper)) {
assert(stopper == ')' && SEE(EOS));
ERR(REG_EPAREN);
}
/*
* Optimize out simple cases.
*/
if (branch == branches) { /* only one branch */
assert(branch->right == NULL);
t = branch->left;
branch->left = NULL;
freesubre(v, branches);
branches = t;
} else if (!MESSY(branches->flags)) { /* no interesting innards */
freesubre(v, branches->left);
branches->left = NULL;
freesubre(v, branches->right);
branches->right = NULL;
branches->op = '=';
}
return branches;
}
/*
- parsebranch - parse one branch of an RE
* This mostly manages concatenation, working closely with parseqatom().
* Concatenated things are bundled up as much as possible, with separate
* ',' nodes introduced only when necessary due to substructure.
^ static struct subre *parsebranch(struct vars *, int, int, struct state *,
^ struct state *, int);
*/
static struct subre *
parsebranch(
struct vars *v,
int stopper, /* EOS or ')' */
int type, /* LACON (lookahead subRE) or PLAIN */
struct state *left, /* leftmost state */
struct state *right, /* rightmost state */
int partial) /* is this only part of a branch? */
{
struct state *lp; /* left end of current construct */
int seencontent; /* is there anything in this branch yet? */
struct subre *t;
lp = left;
seencontent = 0;
t = subre(v, '=', 0, left, right); /* op '=' is tentative */
NOERRN();
while (!SEE('|') && !SEE(stopper) && !SEE(EOS)) {
if (seencontent) { /* implicit concat operator */
lp = newstate(v->nfa);
NOERRN();
moveins(v->nfa, right, lp);
}
seencontent = 1;
/* NB, recursion in parseqatom() may swallow rest of branch */
parseqatom(v, stopper, type, lp, right, t);
NOERRN();
}
if (!seencontent) { /* empty branch */
if (!partial) {
NOTE(REG_UUNSPEC);
}
assert(lp == left);
EMPTYARC(left, right);
}
return t;
}
/*
- parseqatom - parse one quantified atom or constraint of an RE
* The bookkeeping near the end cooperates very closely with parsebranch(); in
* particular, it contains a recursion that can involve parsing the rest of
* the branch, making this function's name somewhat inaccurate.
^ static void parseqatom(struct vars *, int, int, struct state *,
^ struct state *, struct subre *);
*/
static void
parseqatom(
struct vars *v,
int stopper, /* EOS or ')' */
int type, /* LACON (lookahead subRE) or PLAIN */
struct state *lp, /* left state to hang it on */
struct state *rp, /* right state to hang it on */
struct subre *top) /* subtree top */
{
struct state *s; /* temporaries for new states */
struct state *s2;
#define ARCV(t, val) newarc(v->nfa, t, val, lp, rp)
int m, n;
struct subre *atom; /* atom's subtree */
struct subre *t;
int cap; /* capturing parens? */
int pos; /* positive lookahead? */
int subno; /* capturing-parens or backref number */
int atomtype;
int qprefer; /* quantifier short/long preference */
int f;
struct subre **atomp; /* where the pointer to atom is */
/*
* Initial bookkeeping.
*/
atom = NULL;
assert(lp->nouts == 0); /* must string new code */
assert(rp->nins == 0); /* between lp and rp */
subno = 0; /* just to shut lint up */
/*
* An atom or constraint...
*/
atomtype = v->nexttype;
switch (atomtype) {
/* first, constraints, which end by returning */
case '^':
ARCV('^', 1);
if (v->cflags&REG_NLANCH) {
ARCV(BEHIND, v->nlcolor);
}
NEXT();
return;
case '$':
ARCV('$', 1);
if (v->cflags&REG_NLANCH) {
ARCV(AHEAD, v->nlcolor);
}
NEXT();
return;
case SBEGIN:
ARCV('^', 1); /* BOL */
ARCV('^', 0); /* or BOS */
NEXT();
return;
case SEND:
ARCV('$', 1); /* EOL */
ARCV('$', 0); /* or EOS */
NEXT();
return;
case '<':
wordchrs(v); /* does NEXT() */
s = newstate(v->nfa);
NOERR();
nonword(v, BEHIND, lp, s);
word(v, AHEAD, s, rp);
return;
case '>':
wordchrs(v); /* does NEXT() */
s = newstate(v->nfa);
NOERR();
word(v, BEHIND, lp, s);
nonword(v, AHEAD, s, rp);
return;
case WBDRY:
wordchrs(v); /* does NEXT() */
s = newstate(v->nfa);
NOERR();
nonword(v, BEHIND, lp, s);
word(v, AHEAD, s, rp);
s = newstate(v->nfa);
NOERR();
word(v, BEHIND, lp, s);
nonword(v, AHEAD, s, rp);
return;
case NWBDRY:
wordchrs(v); /* does NEXT() */
s = newstate(v->nfa);
NOERR();
word(v, BEHIND, lp, s);
word(v, AHEAD, s, rp);
s = newstate(v->nfa);
NOERR();
nonword(v, BEHIND, lp, s);
nonword(v, AHEAD, s, rp);
return;
case LACON: /* lookahead constraint */
pos = v->nextvalue;
NEXT();
s = newstate(v->nfa);
s2 = newstate(v->nfa);
NOERR();
t = parse(v, ')', LACON, s, s2);
freesubre(v, t); /* internal structure irrelevant */
assert(SEE(')') || ISERR());
NEXT();
n = newlacon(v, s, s2, pos);
NOERR();
ARCV(LACON, n);
return;
/*
* Then errors, to get them out of the way.
*/
case '*':
case '+':
case '?':
case '{':
ERR(REG_BADRPT);
return;
default:
ERR(REG_ASSERT);
return;
/*
* Then plain characters, and minor variants on that theme.
*/
case ')': /* unbalanced paren */
if ((v->cflags&REG_ADVANCED) != REG_EXTENDED) {
ERR(REG_EPAREN);
return;
}
/*
* Legal in EREs due to specification botch.
*/
NOTE(REG_UPBOTCH);
/* FALLTHRU */
case PLAIN:
onechr(v, v->nextvalue, lp, rp);
okcolors(v->nfa, v->cm);
NOERR();
NEXT();
break;
case '[':
if (v->nextvalue == 1) {
bracket(v, lp, rp);
} else {
cbracket(v, lp, rp);
}
assert(SEE(']') || ISERR());
NEXT();
break;
case '.':
rainbow(v->nfa, v->cm, PLAIN,
(v->cflags&REG_NLSTOP) ? v->nlcolor : COLORLESS, lp, rp);
NEXT();
break;
/*
* And finally the ugly stuff.
*/
case '(': /* value flags as capturing or non */
cap = (type == LACON) ? 0 : v->nextvalue;
if (cap) {
v->nsubexp++;
subno = v->nsubexp;
if ((size_t)subno >= v->nsubs) {
moresubs(v, subno);
}
assert((size_t)subno < v->nsubs);
} else {
atomtype = PLAIN; /* something that's not '(' */
}
NEXT();
/*
* Need new endpoints because tree will contain pointers.
*/
s = newstate(v->nfa);
s2 = newstate(v->nfa);
NOERR();
EMPTYARC(lp, s);
EMPTYARC(s2, rp);
NOERR();
atom = parse(v, ')', PLAIN, s, s2);
assert(SEE(')') || ISERR());
NEXT();
NOERR();
if (cap) {
v->subs[subno] = atom;
t = subre(v, '(', atom->flags|CAP, lp, rp);
NOERR();
t->subno = subno;
t->left = atom;
atom = t;
}
/*
* Postpone everything else pending possible {0}.
*/
break;
case BACKREF: /* the Feature From The Black Lagoon */
INSIST(type != LACON, REG_ESUBREG);
INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
NOERR();
assert(v->nextvalue > 0);
atom = subre(v, 'b', BACKR, lp, rp);
NOERR();
subno = v->nextvalue;
atom->subno = subno;
EMPTYARC(lp, rp); /* temporarily, so there's something */
NEXT();
break;
}
/*
* ...and an atom may be followed by a quantifier.
*/
switch (v->nexttype) {
case '*':
m = 0;
n = DUPINF;
qprefer = (v->nextvalue) ? LONGER : SHORTER;
NEXT();
break;
case '+':
m = 1;
n = DUPINF;
qprefer = (v->nextvalue) ? LONGER : SHORTER;
NEXT();
break;
case '?':
m = 0;
n = 1;
qprefer = (v->nextvalue) ? LONGER : SHORTER;
NEXT();
break;
case '{':
NEXT();
m = scannum(v);
if (EAT(',')) {
if (SEE(DIGIT)) {
n = scannum(v);
} else {
n = DUPINF;
}
if (m > n) {
ERR(REG_BADBR);
return;
}
/*
* {m,n} exercises preference, even if it's {m,m}
*/
qprefer = (v->nextvalue) ? LONGER : SHORTER;
} else {
n = m;
/*
* {m} passes operand's preference through.
*/
qprefer = 0;
}
if (!SEE('}')) { /* catches errors too */
ERR(REG_BADBR);
return;
}
NEXT();
break;
default: /* no quantifier */
m = n = 1;
qprefer = 0;
break;
}
/*
* Annoying special case: {0} or {0,0} cancels everything.
*/
if (m == 0 && n == 0) {
if (atom != NULL) {
freesubre(v, atom);
}
if (atomtype == '(') {
v->subs[subno] = NULL;
}
delsub(v->nfa, lp, rp);
EMPTYARC(lp, rp);
return;
}
/*
* If not a messy case, avoid hard part.
*/
assert(!MESSY(top->flags));
f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f))) {
if (!(m == 1 && n == 1)) {
repeat(v, lp, rp, m, n);
}
if (atom != NULL) {
freesubre(v, atom);
}
top->flags = f;
return;
}
/*
* hard part: something messy
* That is, capturing parens, back reference, short/long clash, or an atom
* with substructure containing one of those.
*/
/*
* Now we'll need a subre for the contents even if they're boring.
*/
if (atom == NULL) {
atom = subre(v, '=', 0, lp, rp);
NOERR();
}
/*
* Prepare a general-purpose state skeleton.
*
* In the no-backrefs case, we want this:
*
* [lp] ---> [s] ---prefix---> [begin] ---atom---> [end] ---rest---> [rp]
*
* where prefix is some repetitions of atom. In the general case we need
*
* [lp] ---> [s] ---iterator---> [s2] ---rest---> [rp]
*
* where the iterator wraps around [begin] ---atom---> [end]
*
* We make the s state here for both cases; s2 is made below if needed
*/
s = newstate(v->nfa); /* first, new endpoints for the atom */
s2 = newstate(v->nfa);
NOERR();
moveouts(v->nfa, lp, s);
moveins(v->nfa, rp, s2);
NOERR();
atom->begin = s;
atom->end = s2;
s = newstate(v->nfa); /* set up starting state */
NOERR();
EMPTYARC(lp, s);
NOERR();
/*
* Break remaining subRE into x{...} and what follows.
*/
t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
NOERR();
t->left = atom;
atomp = &t->left;
/*
* Here we should recurse... but we must postpone that to the end.
*/
/*
* Split top into prefix and remaining.
*/
assert(top->op == '=' && top->left == NULL && top->right == NULL);
top->left = subre(v, '=', top->flags, top->begin, lp);
NOERR();
top->op = '.';
top->right = t;
/*
* If it's a backref, now is the time to replicate the subNFA.
*/
if (atomtype == BACKREF) {
assert(atom->begin->nouts == 1); /* just the EMPTY */
delsub(v->nfa, atom->begin, atom->end);
assert(v->subs[subno] != NULL);
/*
* And here's why the recursion got postponed: it must wait until the
* skeleton is filled in, because it may hit a backref that wants to
* copy the filled-in skeleton.
*/
dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
atom->begin, atom->end);
NOERR();
}
/*
* It's quantifier time. If the atom is just a backref, we'll let it deal
* with quantifiers internally.
*/
if (atomtype == BACKREF) {
/*
* Special case: backrefs have internal quantifiers.
*/
EMPTYARC(s, atom->begin); /* empty prefix */
/*
* Just stuff everything into atom.
*/
repeat(v, atom->begin, atom->end, m, n);
atom->min = (short) m;
atom->max = (short) n;
atom->flags |= COMBINE(qprefer, atom->flags);
/* rest of branch can be strung starting from atom->end */
s2 = atom->end;
} else if (m == 1 && n == 1) {
/*
* No/vacuous quantifier: done.
*/
EMPTYARC(s, atom->begin); /* empty prefix */
/* rest of branch can be strung starting from atom->end */
s2 = atom->end;
} else if (m > 0 && !(atom->flags & BACKR)) {
/*
* If there's no backrefs involved, we can turn x{m,n} into
* x{m-1,n-1}x, with capturing parens in only the second x. This
* is valid because we only care about capturing matches from the
* final iteration of the quantifier. It's a win because we can
* implement the backref-free left side as a plain DFA node, since
* we don't really care where its submatches are.
*/
dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
assert(m >= 1 && m != DUPINF && n >= 1);
repeat(v, s, atom->begin, m-1, (n == DUPINF) ? n : n-1);
f = COMBINE(qprefer, atom->flags);
t = subre(v, '.', f, s, atom->end); /* prefix and atom */
NOERR();
t->left = subre(v, '=', PREF(f), s, atom->begin);
NOERR();
t->right = atom;
*atomp = t;
/* rest of branch can be strung starting from atom->end */
s2 = atom->end;
} else {
/* general case: need an iteration node */
s2 = newstate(v->nfa);
NOERR();
moveouts(v->nfa, atom->end, s2);
NOERR();
dupnfa(v->nfa, atom->begin, atom->end, s, s2);
repeat(v, s, s2, m, n);
f = COMBINE(qprefer, atom->flags);
t = subre(v, '*', f, s, s2);
NOERR();
t->min = (short) m;
t->max = (short) n;
t->left = atom;
*atomp = t;
/* rest of branch is to be strung from iteration's end state */
}
/*
* And finally, look after that postponed recursion.
*/
t = top->right;
if (!(SEE('|') || SEE(stopper) || SEE(EOS))) {
t->right = parsebranch(v, stopper, type, s2, rp, 1);
} else {
EMPTYARC(s2, rp);
t->right = subre(v, '=', 0, s2, rp);
}
NOERR();
assert(SEE('|') || SEE(stopper) || SEE(EOS));
t->flags |= COMBINE(t->flags, t->right->flags);
top->flags |= COMBINE(top->flags, t->flags);
}
/*
- nonword - generate arcs for non-word-character ahead or behind
^ static void nonword(struct vars *, int, struct state *, struct state *);
*/
static void
nonword(
struct vars *v,
int dir, /* AHEAD or BEHIND */
struct state *lp,
struct state *rp)
{
int anchor = (dir == AHEAD) ? '$' : '^';
assert(dir == AHEAD || dir == BEHIND);
newarc(v->nfa, anchor, 1, lp, rp);
newarc(v->nfa, anchor, 0, lp, rp);
colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
/* (no need for special attention to \n) */
}
/*
- word - generate arcs for word character ahead or behind
^ static void word(struct vars *, int, struct state *, struct state *);
*/
static void
word(
struct vars *v,
int dir, /* AHEAD or BEHIND */
struct state *lp,
struct state *rp)
{
assert(dir == AHEAD || dir == BEHIND);
cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
/* (no need for special attention to \n) */
}
/*
- scannum - scan a number
^ static int scannum(struct vars *);
*/
static int /* value, <= DUPMAX */
scannum(
struct vars *v)
{
int n = 0;
while (SEE(DIGIT) && n < DUPMAX) {
n = n*10 + v->nextvalue;
NEXT();
}
if (SEE(DIGIT) || n > DUPMAX) {
ERR(REG_BADBR);
return 0;
}
return n;
}
/*
- repeat - replicate subNFA for quantifiers
* The sub-NFA strung from lp to rp is modified to represent m to n
* repetitions of its initial contents.
* The duplication sequences used here are chosen carefully so that any
* pointers starting out pointing into the subexpression end up pointing into
* the last occurrence. (Note that it may not be strung between the same left
* and right end states, however!) This used to be important for the subRE
* tree, although the important bits are now handled by the in-line code in
* parse(), and when this is called, it doesn't matter any more.
^ static void repeat(struct vars *, struct state *, struct state *, int, int);
*/
static void
repeat(
struct vars *v,
struct state *lp,
struct state *rp,
int m,
int n)
{
#define SOME 2
#define INF 3
#define PAIR(x, y) ((x)*4 + (y))
#define REDUCE(x) ( ((x) == DUPINF) ? INF : (((x) > 1) ? SOME : (x)) )
const int rm = REDUCE(m);
const int rn = REDUCE(n);
struct state *s, *s2;
switch (PAIR(rm, rn)) {
case PAIR(0, 0): /* empty string */
delsub(v->nfa, lp, rp);
EMPTYARC(lp, rp);
break;
case PAIR(0, 1): /* do as x| */
EMPTYARC(lp, rp);
break;
case PAIR(0, SOME): /* do as x{1,n}| */
repeat(v, lp, rp, 1, n);
NOERR();
EMPTYARC(lp, rp);
break;
case PAIR(0, INF): /* loop x around */
s = newstate(v->nfa);
NOERR();
moveouts(v->nfa, lp, s);
moveins(v->nfa, rp, s);
EMPTYARC(lp, s);
EMPTYARC(s, rp);
break;
case PAIR(1, 1): /* no action required */
break;
case PAIR(1, SOME): /* do as x{0,n-1}x = (x{1,n-1}|)x */
s = newstate(v->nfa);
NOERR();
moveouts(v->nfa, lp, s);
dupnfa(v->nfa, s, rp, lp, s);
NOERR();
repeat(v, lp, s, 1, n-1);
NOERR();
EMPTYARC(lp, s);
break;
case PAIR(1, INF): /* add loopback arc */
s = newstate(v->nfa);
s2 = newstate(v->nfa);
NOERR();
moveouts(v->nfa, lp, s);
moveins(v->nfa, rp, s2);
EMPTYARC(lp, s);
EMPTYARC(s2, rp);
EMPTYARC(s2, s);
break;
case PAIR(SOME, SOME): /* do as x{m-1,n-1}x */
s = newstate(v->nfa);
NOERR();
moveouts(v->nfa, lp, s);
dupnfa(v->nfa, s, rp, lp, s);
NOERR();
repeat(v, lp, s, m-1, n-1);
break;
case PAIR(SOME, INF): /* do as x{m-1,}x */
s = newstate(v->nfa);
NOERR();
moveouts(v->nfa, lp, s);
dupnfa(v->nfa, s, rp, lp, s);
NOERR();
repeat(v, lp, s, m-1, n);
break;
default:
ERR(REG_ASSERT);
break;
}
}
/*
- bracket - handle non-complemented bracket expression
* Also called from cbracket for complemented bracket expressions.
^ static void bracket(struct vars *, struct state *, struct state *);
*/
static void
bracket(
struct vars *v,
struct state *lp,
struct state *rp)
{
assert(SEE('['));
NEXT();
while (!SEE(']') && !SEE(EOS)) {
brackpart(v, lp, rp);
}
assert(SEE(']') || ISERR());
okcolors(v->nfa, v->cm);
}
/*
- cbracket - handle complemented bracket expression
* We do it by calling bracket() with dummy endpoints, and then complementing
* the result. The alternative would be to invoke rainbow(), and then delete
* arcs as the b.e. is seen... but that gets messy.
^ static void cbracket(struct vars *, struct state *, struct state *);
*/
static void
cbracket(
struct vars *v,
struct state *lp,
struct state *rp)
{
struct state *left = newstate(v->nfa);
struct state *right = newstate(v->nfa);
NOERR();
bracket(v, left, right);
if (v->cflags&REG_NLSTOP) {
newarc(v->nfa, PLAIN, v->nlcolor, left, right);
}
NOERR();
assert(lp->nouts == 0); /* all outarcs will be ours */
/*
* Easy part of complementing, and all there is to do since the MCCE code
* was removed.
*/
colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
NOERR();
dropstate(v->nfa, left);
assert(right->nins == 0);
freestate(v->nfa, right);
return;
}
/*
- brackpart - handle one item (or range) within a bracket expression
^ static void brackpart(struct vars *, struct state *, struct state *);
*/
static void
brackpart(
struct vars *v,
struct state *lp,
struct state *rp)
{
celt startc, endc;
struct cvec *cv;
const chr *startp, *endp;
chr c;
/*
* Parse something, get rid of special cases, take shortcuts.
*/
switch (v->nexttype) {
case RANGE: /* a-b-c or other botch */
ERR(REG_ERANGE);
return;
break;
case PLAIN:
c = v->nextvalue;
NEXT();
/*
* Shortcut for ordinary chr (not range).
*/
if (!SEE(RANGE)) {
onechr(v, c, lp, rp);
return;
}
startc = element(v, &c, &c+1);
NOERR();
break;
case COLLEL:
startp = v->now;
endp = scanplain(v);
INSIST(startp < endp, REG_ECOLLATE);
NOERR();
startc = element(v, startp, endp);
NOERR();
break;
case ECLASS:
startp = v->now;
endp = scanplain(v);
INSIST(startp < endp, REG_ECOLLATE);
NOERR();
startc = element(v, startp, endp);
NOERR();
cv = eclass(v, startc, (v->cflags&REG_ICASE));
NOERR();
dovec(v, cv, lp, rp);
return;
break;
case CCLASS:
startp = v->now;
endp = scanplain(v);
INSIST(startp < endp, REG_ECTYPE);
NOERR();
cv = cclass(v, startp, endp, (v->cflags&REG_ICASE));
NOERR();
dovec(v, cv, lp, rp);
return;
break;
default:
ERR(REG_ASSERT);
return;
break;
}
if (SEE(RANGE)) {
NEXT();
switch (v->nexttype) {
case PLAIN:
case RANGE:
c = v->nextvalue;
NEXT();
endc = element(v, &c, &c+1);
NOERR();
break;
case COLLEL:
startp = v->now;
endp = scanplain(v);
INSIST(startp < endp, REG_ECOLLATE);
NOERR();
endc = element(v, startp, endp);
NOERR();
break;
default:
ERR(REG_ERANGE);
return;
break;
}
} else {
endc = startc;
}
/*
* Ranges are unportable. Actually, standard C does guarantee that digits
* are contiguous, but making that an exception is just too complicated.
*/
if (startc != endc) {
NOTE(REG_UUNPORT);
}
cv = range(v, startc, endc, (v->cflags&REG_ICASE));
NOERR();
dovec(v, cv, lp, rp);
}
/*
- scanplain - scan PLAIN contents of [. etc.
* Certain bits of trickery in lex.c know that this code does not try to look
* past the final bracket of the [. etc.
^ static const chr *scanplain(struct vars *);
*/
static const chr * /* just after end of sequence */
scanplain(
struct vars *v)
{
const chr *endp;
assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
NEXT();
endp = v->now;
while (SEE(PLAIN)) {
endp = v->now;
NEXT();
}
assert(SEE(END) || ISERR());
NEXT();
return endp;
}
/*
- onechr - fill in arcs for a plain character, and possible case complements
* This is mostly a shortcut for efficient handling of the common case.
^ static void onechr(struct vars *, pchr, struct state *, struct state *);
*/
static void
onechr(
struct vars *v,
pchr c,
struct state *lp,
struct state *rp)
{
if (!(v->cflags&REG_ICASE)) {
newarc(v->nfa, PLAIN, subcolor(v->cm, c), lp, rp);
return;
}
/*
* Rats, need general case anyway...
*/
dovec(v, allcases(v, c), lp, rp);
}
/*
- dovec - fill in arcs for each element of a cvec
^ static void dovec(struct vars *, struct cvec *, struct state *,
^ struct state *);
*/
static void
dovec(
struct vars *v,
struct cvec *cv,
struct state *lp,
struct state *rp)
{
chr ch, from, to;
const chr *p;
int i;
for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) {
ch = *p;
newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp);
}
for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) {
from = *p;
to = *(p+1);
if (from <= to) {
subrange(v, from, to, lp, rp);
}
}
}
/*
- wordchrs - set up word-chr list for word-boundary stuff, if needed
* The list is kept as a bunch of arcs between two dummy states; it's disposed
* of by the unreachable-states sweep in NFA optimization. Does NEXT(). Must
* not be called from any unusual lexical context. This should be reconciled
* with the \w etc. handling in lex.c, and should be cleaned up to reduce
* dependencies on input scanning.
^ static void wordchrs(struct vars *);
*/
static void
wordchrs(
struct vars *v)
{
struct state *left, *right;
if (v->wordchrs != NULL) {
NEXT(); /* for consistency */
return;
}
left = newstate(v->nfa);
right = newstate(v->nfa);
NOERR();
/*
* Fine point: implemented with [::], and lexer will set REG_ULOCALE.
*/
lexword(v);
NEXT();
assert(v->savenow != NULL && SEE('['));
bracket(v, left, right);
assert((v->savenow != NULL && SEE(']')) || ISERR());
NEXT();
NOERR();
v->wordchrs = left;
}
/*
- subre - allocate a subre
^ static struct subre *subre(struct vars *, int, int, struct state *,
^ struct state *);
*/
static struct subre *
subre(
struct vars *v,
int op,
int flags,
struct state *begin,
struct state *end)
{
struct subre *ret = v->treefree;
if (ret != NULL) {
v->treefree = ret->left;
} else {
ret = (struct subre *) MALLOC(sizeof(struct subre));
if (ret == NULL) {
ERR(REG_ESPACE);
return NULL;
}
ret->chain = v->treechain;
v->treechain = ret;
}
assert(strchr("=b|.*(", op) != NULL);
ret->op = op;
ret->flags = flags;
ret->id = 0; /* will be assigned later */
ret->subno = 0;
ret->min = ret->max = 1;
ret->left = NULL;
ret->right = NULL;
ret->begin = begin;
ret->end = end;
ZAPCNFA(ret->cnfa);
return ret;
}
/*
- freesubre - free a subRE subtree
^ static void freesubre(struct vars *, struct subre *);
*/
static void
freesubre(
struct vars *v, /* might be NULL */
struct subre *sr)
{
if (sr == NULL) {
return;
}
if (sr->left != NULL) {
freesubre(v, sr->left);
}
if (sr->right != NULL) {
freesubre(v, sr->right);
}
freesrnode(v, sr);
}
/*
- freesrnode - free one node in a subRE subtree
^ static void freesrnode(struct vars *, struct subre *);
*/
static void
freesrnode(
struct vars *v, /* might be NULL */
struct subre *sr)
{
if (sr == NULL) {
return;
}
if (!NULLCNFA(sr->cnfa)) {
freecnfa(&sr->cnfa);
}
sr->flags = 0;
if (v != NULL && v->treechain != NULL) {
/* we're still parsing, maybe we can reuse the subre */
sr->left = v->treefree;
v->treefree = sr;
} else {
FREE(sr);
}
}
/*
- numst - number tree nodes (assigning "id" indexes)
^ static int numst(struct subre *, int);
*/
static int /* next number */
numst(
struct subre *t,
int start) /* starting point for subtree numbers */
{
int i;
assert(t != NULL);
i = start;
t->id = (short) i++;
if (t->left != NULL) {
i = numst(t->left, i);
}
if (t->right != NULL) {
i = numst(t->right, i);
}
return i;
}
/*
- markst - mark tree nodes as INUSE
* Note: this is a great deal more subtle than it looks. During initial
* parsing of a regex, all subres are linked into the treechain list;
* discarded ones are also linked into the treefree list for possible reuse.
* After we are done creating all subres required for a regex, we run markst()
* then cleanst(), which results in discarding all subres not reachable from
* v->tree. We then clear v->treechain, indicating that subres must be found
* by descending from v->tree. This changes the behavior of freesubre(): it
* will henceforth FREE() unwanted subres rather than sticking them into the
* treefree list. (Doing that any earlier would result in dangling links in
* the treechain list.) This all means that freev() will clean up correctly
* if invoked before or after markst()+cleanst(); but it would not work if
* called partway through this state conversion, so we mustn't error out
* in or between these two functions.
^ static void markst(struct subre *);
*/
static void
markst(
struct subre *t)
{
assert(t != NULL);
t->flags |= INUSE;
if (t->left != NULL) {
markst(t->left);
}
if (t->right != NULL) {
markst(t->right);
}
}
/*
- cleanst - free any tree nodes not marked INUSE
^ static void cleanst(struct vars *);
*/
static void
cleanst(
struct vars *v)
{
struct subre *t;
struct subre *next;
for (t = v->treechain; t != NULL; t = next) {
next = t->chain;
if (!(t->flags&INUSE)) {
FREE(t);
}
}
v->treechain = NULL;
v->treefree = NULL; /* just on general principles */
}
/*
- nfatree - turn a subRE subtree into a tree of compacted NFAs
^ static long nfatree(struct vars *, struct subre *, FILE *);
*/
static long /* optimize results from top node */
nfatree(
struct vars *v,
struct subre *t,
FILE *f) /* for debug output */
{
assert(t != NULL && t->begin != NULL);
if (t->left != NULL) {
(DISCARD) nfatree(v, t->left, f);
}
if (t->right != NULL) {
(DISCARD) nfatree(v, t->right, f);
}
return nfanode(v, t, f);
}
/*
- nfanode - do one NFA for nfatree
^ static long nfanode(struct vars *, struct subre *, FILE *);
*/
static long /* optimize results */
nfanode(
struct vars *v,
struct subre *t,
FILE *f) /* for debug output */
{
struct nfa *nfa;
long ret = 0;
char idbuf[50];
assert(t->begin != NULL);
if (f != NULL) {
fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
stid(t, idbuf, sizeof(idbuf)));
}
nfa = newnfa(v, v->cm, v->nfa);
NOERRZ();
dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
if (!ISERR()) {
specialcolors(nfa);
ret = optimize(nfa, f);
}
if (!ISERR()) {
compact(nfa, &t->cnfa);
}
freenfa(nfa);
return ret;
}
/*
- newlacon - allocate a lookahead-constraint subRE
^ static int newlacon(struct vars *, struct state *, struct state *, int);
*/
static int /* lacon number */
newlacon(
struct vars *v,
struct state *begin,
struct state *end,
int pos)
{
int n;
struct subre *newlacons;
struct subre *sub;
if (v->nlacons == 0) {
n = 1; /* skip 0th */
newlacons = (struct subre *) MALLOC(2 * sizeof(struct subre));
} else {
n = v->nlacons;
newlacons = (struct subre *) REALLOC(v->lacons,
(n + 1) * sizeof(struct subre));
}
if (newlacons == NULL) {
ERR(REG_ESPACE);
return 0;
}
v->lacons = newlacons;
v->nlacons = n + 1;
sub = &v->lacons[n];
sub->begin = begin;
sub->end = end;
sub->subno = pos;
ZAPCNFA(sub->cnfa);
return n;
}
/*
- freelacons - free lookahead-constraint subRE vector
^ static void freelacons(struct subre *, int);
*/
static void
freelacons(
struct subre *subs,
int n)
{
struct subre *sub;
int i;
assert(n > 0);
for (sub=subs+1, i=n-1; i>0; sub++, i--) { /* no 0th */
if (!NULLCNFA(sub->cnfa)) {
freecnfa(&sub->cnfa);
}
}
FREE(subs);
}
/*
- rfree - free a whole RE (insides of regfree)
^ static void rfree(regex_t *);
*/
static void
rfree(
regex_t *re)
{
struct guts *g;
if (re == NULL || re->re_magic != REMAGIC) {
return;
}
re->re_magic = 0; /* invalidate RE */
g = (struct guts *) re->re_guts;
re->re_guts = NULL;
re->re_fns = NULL;
if (g != NULL) {
g->magic = 0;
freecm(&g->cmap);
if (g->tree != NULL) {
freesubre(NULL, g->tree);
}
if (g->lacons != NULL) {
freelacons(g->lacons, g->nlacons);
}
if (!NULLCNFA(g->search)) {
freecnfa(&g->search);
}
FREE(g);
}
}
/*
- dump - dump an RE in human-readable form
^ static void dump(regex_t *, FILE *);
*/
static void
dump(
regex_t *re,
FILE *f)
{
#ifdef REG_DEBUG
struct guts *g;
int i;
if (re->re_magic != REMAGIC) {
fprintf(f, "bad magic number (0x%x not 0x%x)\n",
re->re_magic, REMAGIC);
}
if (re->re_guts == NULL) {
fprintf(f, "NULL guts!!!\n");
return;
}
g = (struct guts *) re->re_guts;
if (g->magic != GUTSMAGIC) {
fprintf(f, "bad guts magic number (0x%x not 0x%x)\n",
g->magic, GUTSMAGIC);
}
fprintf(f, "\n\n\n========= DUMP ==========\n");
fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n",
(int) re->re_nsub, re->re_info, re->re_csize, g->ntree);
dumpcolors(&g->cmap, f);
if (!NULLCNFA(g->search)) {
fprintf(f, "\nsearch:\n");
dumpcnfa(&g->search, f);
}
for (i = 1; i < g->nlacons; i++) {
fprintf(f, "\nla%d (%s):\n", i,
(g->lacons[i].subno) ? "positive" : "negative");
dumpcnfa(&g->lacons[i].cnfa, f);
}
fprintf(f, "\n");
dumpst(g->tree, f, 0);
#else
(void)re;
(void)f;
#endif
}
/*
- dumpst - dump a subRE tree
^ static void dumpst(struct subre *, FILE *, int);
*/
static void
dumpst(
struct subre *t,
FILE *f,
int nfapresent) /* is the original NFA still around? */
{
if (t == NULL) {
fprintf(f, "null tree\n");
} else {
stdump(t, f, nfapresent);
}
fflush(f);
}
/*
- stdump - recursive guts of dumpst
^ static void stdump(struct subre *, FILE *, int);
*/
static void
stdump(
struct subre *t,
FILE *f,
int nfapresent) /* is the original NFA still around? */
{
char idbuf[50];
fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
if (t->flags&LONGER) {
fprintf(f, " longest");
}
if (t->flags&SHORTER) {
fprintf(f, " shortest");
}
if (t->flags&MIXED) {
fprintf(f, " hasmixed");
}
if (t->flags&CAP) {
fprintf(f, " hascapture");
}
if (t->flags&BACKR) {
fprintf(f, " hasbackref");
}
if (!(t->flags&INUSE)) {
fprintf(f, " UNUSED");
}
if (t->subno != 0) {
fprintf(f, " (#%d)", t->subno);
}
if (t->min != 1 || t->max != 1) {
fprintf(f, " {%d,", t->min);
if (t->max != DUPINF) {
fprintf(f, "%d", t->max);
}
fprintf(f, "}");
}
if (nfapresent) {
fprintf(f, " %ld-%ld", (long)t->begin->no, (long)t->end->no);
}
if (t->left != NULL) {
fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf)));
}
if (t->right != NULL) {
fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf)));
}
if (!NULLCNFA(t->cnfa)) {
fprintf(f, "\n");
dumpcnfa(&t->cnfa, f);
}
fprintf(f, "\n");
if (t->left != NULL) {
stdump(t->left, f, nfapresent);
}
if (t->right != NULL) {
stdump(t->right, f, nfapresent);
}
}
/*
- stid - identify a subtree node for dumping
^ static const char *stid(struct subre *, char *, size_t);
*/
static const char * /* points to buf or constant string */
stid(
struct subre *t,
char *buf,
size_t bufsize)
{
/*
* Big enough for hex int or decimal t->id?
*/
if (bufsize < sizeof(void*)*2 + 3 || bufsize < sizeof(t->id)*3 + 1) {
return "unable";
}
if (t->id != 0) {
sprintf(buf, "%d", t->id);
} else {
sprintf(buf, "%p", t);
}
return buf;
}
#include "regc_lex.c"
#include "regc_color.c"
#include "regc_nfa.c"
#include "regc_cvec.c"
#include "regc_locale.c"
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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