greenplumn regcomp 源码
greenplumn regcomp 代码
文件路径：/src/backend/regex/regcomp.c
/*
* 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.
*
* src/backend/regex/regcomp.c
*
*/
#include "regex/regguts.h"
/*
* forward declarations, up here so forward datatypes etc. are defined early
*/
/* === regcomp.c === */
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 *, chr, struct state *, struct state *);
static void wordchrs(struct vars *);
static void processlacon(struct vars *, struct state *, struct state *, int,
struct state *, struct state *);
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 void optst(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 *, int, FILE *);
static int newlacon(struct vars *, struct state *, struct state *, int);
static void freelacons(struct subre *, int);
static void rfree(regex_t *);
static int rcancelrequested(void);
static int rstacktoodeep(void);
#ifdef REG_DEBUG
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);
#endif
/* === 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 chr lexdigits(struct vars *, int, int, int);
static int brenext(struct vars *, chr);
static void skip(struct vars *);
static chr newline(void);
static chr chrnamed(struct vars *, const chr *, const chr *, chr);
/* === regc_color.c === */
static void initcm(struct vars *, struct colormap *);
static void freecm(struct colormap *);
static color maxcolor(struct colormap *);
static color newcolor(struct colormap *);
static void freecolor(struct colormap *, color);
static color pseudocolor(struct colormap *);
static color subcolor(struct colormap *, chr);
static color subcolorhi(struct colormap *, color *);
static color newsub(struct colormap *, color);
static int newhicolorrow(struct colormap *, int);
static void newhicolorcols(struct colormap *);
static void subcolorcvec(struct vars *, struct cvec *, struct state *, struct state *);
static void subcoloronechr(struct vars *, chr, struct state *, struct state *, color *);
static void subcoloronerange(struct vars *, chr, chr, struct state *, struct state *, color *);
static void subcoloronerow(struct vars *, int, struct state *, struct state *, color *);
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, color, 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 dumpchr(chr, 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, color, struct state *, struct state *);
static void createarc(struct nfa *, int, color, 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, color);
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 *);
static void cleartraverse(struct nfa *, struct state *);
static struct state *single_color_transition(struct state *, 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 *);
static void dumpcnfa(struct cnfa *, FILE *);
static void dumpcstate(int, struct cnfa *, FILE *);
#endif
/* === regc_cvec.c === */
static struct cvec *newcvec(int, int);
static struct cvec *clearcvec(struct cvec *);
static void addchr(struct cvec *, chr);
static void addrange(struct cvec *, chr, chr);
static struct cvec *getcvec(struct vars *, int, int);
static void freecvec(struct cvec *);
/* === regc_pg_locale.c === */
static int pg_wc_isdigit(pg_wchar c);
static int pg_wc_isalpha(pg_wchar c);
static int pg_wc_isalnum(pg_wchar c);
static int pg_wc_isupper(pg_wchar c);
static int pg_wc_islower(pg_wchar c);
static int pg_wc_isgraph(pg_wchar c);
static int pg_wc_isprint(pg_wchar c);
static int pg_wc_ispunct(pg_wchar c);
static int pg_wc_isspace(pg_wchar c);
static pg_wchar pg_wc_toupper(pg_wchar c);
static pg_wchar pg_wc_tolower(pg_wchar c);
/* === regc_locale.c === */
static chr element(struct vars *, const chr *, const chr *);
static struct cvec *range(struct vars *, chr, chr, int);
static int before(chr, chr);
static struct cvec *eclass(struct vars *, chr, int);
static struct cvec *cclass(struct vars *, const chr *, const chr *, int);
static int cclass_column_index(struct colormap *, chr);
static struct cvec *allcases(struct vars *, chr);
static int cmp(const chr *, const chr *, size_t);
static int casecmp(const chr *, const chr *, size_t);
/* 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; /* lookaround-constraint vector */
int nlacons; /* size of lacons[]; note that only slots
* numbered 1 .. nlacons-1 are used */
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 */
#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' /* lookaround 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 */
rcancelrequested, /* check for cancel request */
rstacktoodeep /* check for stack getting dangerously deep */
};
/*
* pg_regcomp - compile regular expression
*
* Note: on failure, no resources remain allocated, so pg_regfree()
* need not be applied to re.
*/
int
pg_regcomp(regex_t *re,
const chr *string,
size_t len,
int flags,
Oid collation)
{
struct vars var;
struct vars *v = &var;
struct guts *g;
int i;
size_t j;
#ifdef REG_DEBUG
FILE *debug = (flags & REG_PROGRESS) ? stdout : (FILE *) NULL;
#else
FILE *debug = (FILE *) NULL;
#endif
#define CNOERR() { if (ISERR()) return freev(v, v->err); }
/* sanity checks */
if (re == NULL || string == NULL)
return REG_INVARG;
if ((flags & REG_QUOTE) &&
(flags & (REG_ADVANCED | REG_EXPANDED | REG_NEWLINE)))
return REG_INVARG;
if (!(flags & REG_EXTENDED) && (flags & REG_ADVF))
return REG_INVARG;
/* Initialize locale-dependent support */
pg_set_regex_collation(collation);
/* 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_collation = collation;
re->re_guts = NULL;
re->re_fns = VS(&functions);
/* more complex setup, malloced things */
re->re_guts = VS(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, (struct nfa *) NULL);
CNOERR();
/* set up a reasonably-sized transient cvec for getcvec usage */
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();
#ifdef REG_DEBUG
if (debug != NULL)
{
fprintf(debug, "\n\n\n========= RAW ==========\n");
dumpnfa(v->nfa, debug);
dumpst(v->tree, debug, 1);
}
#endif
optst(v, v->tree);
v->ntree = numst(v->tree, 1);
markst(v->tree);
cleanst(v);
#ifdef REG_DEBUG
if (debug != NULL)
{
fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
dumpst(v->tree, debug, 1);
}
#endif
/* 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++)
{
struct subre *lasub = &v->lacons[i];
#ifdef REG_DEBUG
if (debug != NULL)
fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
#endif
/* Prepend .* to pattern if it's a lookbehind LACON */
nfanode(v, lasub, !LATYPE_IS_AHEAD(lasub->subno), debug);
}
CNOERR();
if (v->tree->flags & SHORTER)
NOTE(REG_USHORTEST);
/* build compacted NFAs for tree, lacons, fast search */
#ifdef REG_DEBUG
if (debug != NULL)
fprintf(debug, "\n\n\n========= SEARCH ==========\n");
#endif
/* 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;
#ifdef REG_DEBUG
if (flags & REG_DUMP)
dump(re, stdout);
#endif
assert(v->err == 0);
return freev(v, 0);
}
/*
* moresubs - enlarge subRE vector
*/
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(VS(p), VS(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 *v,
int err)
{
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 */
return v->err;
}
/*
* makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
* NFA must have been optimize()d already.
*/
static void
makesearch(struct vars *v,
struct nfa *nfa)
{
struct arc *a;
struct arc *b;
struct state *pre = nfa->pre;
struct state *s;
struct state *s2;
struct state *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 reachable from pre and elsewhere */
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 *v,
int stopper, /* EOS or ')' */
int type, /* LACON (lookaround subRE) or PLAIN */
struct state *init, /* initial state */
struct state *final) /* final state */
{
struct state *left; /* scaffolding for branch */
struct state *right;
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 it */
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 *v,
int stopper, /* EOS or ')' */
int type, /* LACON (lookaround 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 *v,
int stopper, /* EOS or ')' */
int type, /* LACON (lookaround 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 latype; /* lookaround constraint type */
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;
break;
case '$':
ARCV('$', 1);
if (v->cflags & REG_NLANCH)
ARCV(AHEAD, v->nlcolor);
NEXT();
return;
break;
case SBEGIN:
ARCV('^', 1); /* BOL */
ARCV('^', 0); /* or BOS */
NEXT();
return;
break;
case SEND:
ARCV('$', 1); /* EOL */
ARCV('$', 0); /* or EOS */
NEXT();
return;
break;
case '<':
wordchrs(v); /* does NEXT() */
s = newstate(v->nfa);
NOERR();
nonword(v, BEHIND, lp, s);
word(v, AHEAD, s, rp);
return;
break;
case '>':
wordchrs(v); /* does NEXT() */
s = newstate(v->nfa);
NOERR();
word(v, BEHIND, lp, s);
nonword(v, AHEAD, s, rp);
return;
break;
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;
break;
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;
break;
case LACON: /* lookaround constraint */
latype = v->nextvalue;
NEXT();
s = newstate(v->nfa);
s2 = newstate(v->nfa);
NOERR();
t = parse(v, ')', LACON, s, s2);
freesubre(v, t); /* internal structure irrelevant */
NOERR();
assert(SEE(')'));
NEXT();
processlacon(v, s, s2, latype, lp, rp);
return;
break;
/* then errors, to get them out of the way */
case '*':
case '+':
case '?':
case '{':
ERR(REG_BADRPT);
return;
break;
default:
ERR(REG_ASSERT);
return;
break;
/* 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);
/* fall through into case PLAIN */
/* FALLTHROUGH */
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, ')', type, 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 &&
(qprefer == 0 ||
(atom->flags & (LONGER | SHORTER | MIXED)) == 0 ||
qprefer == (atom->flags & (LONGER | SHORTER | MIXED))))
{
/* 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 *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 *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 /* 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 *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;
struct state *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 *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 *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);
}
/*
* brackpart - handle one item (or range) within a bracket expression
*/
static void
brackpart(struct vars *v,
struct state *lp,
struct state *rp)
{
chr startc;
chr endc;
struct cvec *cv;
const chr *startp;
const chr *endp;
chr c[1];
/* 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[0] = v->nextvalue;
NEXT();
/* shortcut for ordinary chr (not range) */
if (!SEE(RANGE))
{
onechr(v, c[0], 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();
subcolorcvec(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();
subcolorcvec(v, cv, lp, rp);
return;
break;
default:
ERR(REG_ASSERT);
return;
break;
}
if (SEE(RANGE))
{
NEXT();
switch (v->nexttype)
{
case PLAIN:
case RANGE:
c[0] = 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();
subcolorcvec(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 * /* 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 *v,
chr c,
struct state *lp,
struct state *rp)
{
if (!(v->cflags & REG_ICASE))
{
color lastsubcolor = COLORLESS;
subcoloronechr(v, c, lp, rp, &lastsubcolor);
return;
}
/* rats, need general case anyway... */
subcolorcvec(v, allcases(v, c), 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 *v)
{
struct state *left;
struct state *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;
}
/*
* processlacon - generate the NFA representation of a LACON
*
* In the general case this is just newlacon() + newarc(), but some cases
* can be optimized.
*/
static void
processlacon(struct vars *v,
struct state *begin, /* start of parsed LACON sub-re */
struct state *end, /* end of parsed LACON sub-re */
int latype,
struct state *lp, /* left state to hang it on */
struct state *rp) /* right state to hang it on */
{
struct state *s1;
int n;
/*
* Check for lookaround RE consisting of a single plain color arc (or set
* of arcs); this would typically be a simple chr or a bracket expression.
*/
s1 = single_color_transition(begin, end);
switch (latype)
{
case LATYPE_AHEAD_POS:
/* If lookahead RE is just colorset C, convert to AHEAD(C) */
if (s1 != NULL)
{
cloneouts(v->nfa, s1, lp, rp, AHEAD);
return;
}
break;
case LATYPE_AHEAD_NEG:
/* If lookahead RE is just colorset C, convert to AHEAD(^C)|$ */
if (s1 != NULL)
{
colorcomplement(v->nfa, v->cm, AHEAD, s1, lp, rp);
newarc(v->nfa, '$', 1, lp, rp);
newarc(v->nfa, '$', 0, lp, rp);
return;
}
break;
case LATYPE_BEHIND_POS:
/* If lookbehind RE is just colorset C, convert to BEHIND(C) */
if (s1 != NULL)
{
cloneouts(v->nfa, s1, lp, rp, BEHIND);
return;
}
break;
case LATYPE_BEHIND_NEG:
/* If lookbehind RE is just colorset C, convert to BEHIND(^C)|^ */
if (s1 != NULL)
{
colorcomplement(v->nfa, v->cm, BEHIND, s1, lp, rp);
newarc(v->nfa, '^', 1, lp, rp);
newarc(v->nfa, '^', 0, lp, rp);
return;
}
break;
default:
assert(NOTREACHED);
}
/* General case: we need a LACON subre and arc */
n = newlacon(v, begin, end, latype);
newarc(v->nfa, LACON, n, lp, rp);
}
/*
* subre - allocate a subre
*/
static struct subre *
subre(struct vars *v,
int op,
int flags,
struct state *begin,
struct state *end)
{
struct subre *ret = v->treefree;
/*
* Checking for stack overflow here is sufficient to protect parse() and
* its recursive subroutines.
*/
if (STACK_TOO_DEEP(v->re))
{
ERR(REG_ETOOBIG);
return NULL;
}
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 *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 *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);
}
/*
* optst - optimize a subRE subtree
*/
static void
optst(struct vars *v,
struct subre *t)
{
/*
* DGP (2007-11-13): I assume it was the programmer's intent to eventually
* come back and add code to optimize subRE trees, but the routine coded
* just spends effort traversing the tree and doing nothing. We can do
* nothing with less effort.
*/
return;
}
/*
* numst - number tree nodes (assigning "id" indexes)
*/
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 *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 *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 /* 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, 0, f);
}
/*
* nfanode - do one NFA for nfatree or lacons
*
* If converttosearch is true, apply makesearch() to the NFA.
*/
static long /* optimize results */
nfanode(struct vars *v,
struct subre *t,
int converttosearch,
FILE *f) /* for debug output */
{
struct nfa *nfa;
long ret = 0;
assert(t->begin != NULL);
#ifdef REG_DEBUG
if (f != NULL)
{
char idbuf[50];
fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
stid(t, idbuf, sizeof(idbuf)));
}
#endif
nfa = newnfa(v, v->cm, v->nfa);
NOERRZ();
dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
if (!ISERR())
specialcolors(nfa);
if (!ISERR())
ret = optimize(nfa, f);
if (converttosearch && !ISERR())
makesearch(v, nfa);
if (!ISERR())
compact(nfa, &t->cnfa);
freenfa(nfa);
return ret;
}
/*
* newlacon - allocate a lookaround-constraint subRE
*/
static int /* lacon number */
newlacon(struct vars *v,
struct state *begin,
struct state *end,
int latype)
{
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 = latype;
ZAPCNFA(sub->cnfa);
return n;
}
/*
* freelacons - free lookaround-constraint subRE vector
*/
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 *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((struct vars *) NULL, g->tree);
if (g->lacons != NULL)
freelacons(g->lacons, g->nlacons);
if (!NULLCNFA(g->search))
freecnfa(&g->search);
FREE(g);
}
}
/*
* rcancelrequested - check for external request to cancel regex operation
*
* Return nonzero to fail the operation with error code REG_CANCEL,
* zero to keep going
*
* The current implementation is Postgres-specific. If we ever get around
* to splitting the regex code out as a standalone library, there will need
* to be some API to let applications define a callback function for this.
*/
static int
rcancelrequested(void)
{
return InterruptPending && (QueryCancelPending || ProcDiePending);
}
/*
* rstacktoodeep - check for stack getting dangerously deep
*
* Return nonzero to fail the operation with error code REG_ETOOBIG,
* zero to keep going
*
* The current implementation is Postgres-specific. If we ever get around
* to splitting the regex code out as a standalone library, there will need
* to be some API to let applications define a callback function for this.
*/
static int
rstacktoodeep(void)
{
return stack_is_too_deep();
}
#ifdef REG_DEBUG
/*
* dump - dump an RE in human-readable form
*/
static void
dump(regex_t *re,
FILE *f)
{
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++)
{
struct subre *lasub = &g->lacons[i];
const char *latype;
switch (lasub->subno)
{
case LATYPE_AHEAD_POS:
latype = "positive lookahead";
break;
case LATYPE_AHEAD_NEG:
latype = "negative lookahead";
break;
case LATYPE_BEHIND_POS:
latype = "positive lookbehind";
break;
case LATYPE_BEHIND_NEG:
latype = "negative lookbehind";
break;
default:
latype = "???";
break;
}
fprintf(f, "\nla%d (%s):\n", i, latype);
dumpcnfa(&lasub->cnfa, f);
}
fprintf(f, "\n");
dumpst(g->tree, f, 0);
}
/*
* dumpst - dump a subRE tree
*/
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 *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 * /* 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;
}
#endif /* REG_DEBUG */
#include "regc_lex.c"
#include "regc_color.c"
#include "regc_nfa.c"
#include "regc_cvec.c"
#include "regc_pg_locale.c"
#include "regc_locale.c"
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