diff options
Diffstat (limited to 'generic/regcomp.c')
| -rw-r--r-- | generic/regcomp.c | 2124 |
1 files changed, 2124 insertions, 0 deletions
diff --git a/generic/regcomp.c b/generic/regcomp.c new file mode 100644 index 0000000..8e1b61c --- /dev/null +++ b/generic/regcomp.c @@ -0,0 +1,2124 @@ +/* + * re_*comp and friends - compile REs + * This file #includes several others (see the bottom). + */ + +#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 _ANSI_ARGS_((regex_t *, CONST chr *, size_t, int)); +static VOID moresubs _ANSI_ARGS_((struct vars *, int)); +static int freev _ANSI_ARGS_((struct vars *, int)); +static VOID makescan _ANSI_ARGS_((struct vars *, struct nfa *)); +static struct subre *parse _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *)); +static struct subre *parsebranch _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *, int)); +static VOID parseqatom _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *, struct subre *)); +static VOID nonword _ANSI_ARGS_((struct vars *, int, struct state *, struct state *)); +static VOID word _ANSI_ARGS_((struct vars *, int, struct state *, struct state *)); +static int scannum _ANSI_ARGS_((struct vars *)); +static VOID repeat _ANSI_ARGS_((struct vars *, struct state *, struct state *, int, int)); +static VOID bracket _ANSI_ARGS_((struct vars *, struct state *, struct state *)); +static VOID cbracket _ANSI_ARGS_((struct vars *, struct state *, struct state *)); +static VOID brackpart _ANSI_ARGS_((struct vars *, struct state *, struct state *)); +static chr *scanplain _ANSI_ARGS_((struct vars *)); +static VOID leaders _ANSI_ARGS_((struct vars *, struct cvec *)); +static VOID onechr _ANSI_ARGS_((struct vars *, pchr, struct state *, struct state *)); +static VOID dovec _ANSI_ARGS_((struct vars *, struct cvec *, struct state *, struct state *)); +static celt nextleader _ANSI_ARGS_((struct vars *, pchr, pchr)); +static VOID wordchrs _ANSI_ARGS_((struct vars *)); +static struct subre *subre _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *)); +static VOID freesubre _ANSI_ARGS_((struct vars *, struct subre *)); +static VOID freesrnode _ANSI_ARGS_((struct vars *, struct subre *)); +static VOID optst _ANSI_ARGS_((struct vars *, struct subre *)); +static int numst _ANSI_ARGS_((struct subre *, int)); +static VOID markst _ANSI_ARGS_((struct subre *)); +static VOID cleanst _ANSI_ARGS_((struct vars *)); +static int nfatree _ANSI_ARGS_((struct vars *, struct subre *, FILE *)); +static int nfanode _ANSI_ARGS_((struct vars *, struct subre *, FILE *)); +static int newlacon _ANSI_ARGS_((struct vars *, struct state *, struct state *, int)); +static VOID freelacons _ANSI_ARGS_((struct subre *, int)); +static VOID rfree _ANSI_ARGS_((regex_t *)); +static VOID dump _ANSI_ARGS_((regex_t *, FILE *)); +static VOID dumpst _ANSI_ARGS_((struct subre *, FILE *, int)); +static VOID stdump _ANSI_ARGS_((struct subre *, FILE *, int, int)); +/* === regc_lex.c === */ +static VOID lexstart _ANSI_ARGS_((struct vars *)); +static VOID prefixes _ANSI_ARGS_((struct vars *)); +static VOID lexnest _ANSI_ARGS_((struct vars *, chr *, chr *)); +static VOID lexword _ANSI_ARGS_((struct vars *)); +static int next _ANSI_ARGS_((struct vars *)); +static int lexescape _ANSI_ARGS_((struct vars *)); +static chr lexdigits _ANSI_ARGS_((struct vars *, int, int, int)); +static int brenext _ANSI_ARGS_((struct vars *, pchr)); +static VOID skip _ANSI_ARGS_((struct vars *)); +static chr newline _ANSI_ARGS_((NOPARMS)); +static chr chrnamed _ANSI_ARGS_((struct vars *, chr *, chr *, pchr)); +/* === regc_color.c === */ +static VOID initcm _ANSI_ARGS_((struct vars *, struct colormap *)); +static VOID freecm _ANSI_ARGS_((struct colormap *)); +static VOID cmtreefree _ANSI_ARGS_((struct colormap *, union tree *, int)); +static color setcolor _ANSI_ARGS_((struct colormap *, pchr, pcolor)); +static color maxcolor _ANSI_ARGS_((struct colormap *)); +static color newcolor _ANSI_ARGS_((struct colormap *)); +static VOID freecolor _ANSI_ARGS_((struct colormap *, pcolor)); +static color pseudocolor _ANSI_ARGS_((struct colormap *)); +static color subcolor _ANSI_ARGS_((struct colormap *, pchr c)); +static color newsub _ANSI_ARGS_((struct colormap *, pcolor)); +static VOID subrange _ANSI_ARGS_((struct vars *, pchr, pchr, struct state *, struct state *)); +static VOID subblock _ANSI_ARGS_((struct vars *, pchr, struct state *, struct state *)); +static VOID okcolors _ANSI_ARGS_((struct nfa *, struct colormap *)); +static VOID colorchain _ANSI_ARGS_((struct colormap *, struct arc *)); +static VOID uncolorchain _ANSI_ARGS_((struct colormap *, struct arc *)); +#if 0 +static int singleton _ANSI_ARGS_((struct colormap *, pchr c)); +#endif +static VOID rainbow _ANSI_ARGS_((struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *)); +static VOID colorcomplement _ANSI_ARGS_((struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *)); +#ifdef REG_DEBUG +static VOID dumpcolors _ANSI_ARGS_((struct colormap *, FILE *)); +static VOID fillcheck _ANSI_ARGS_((struct colormap *, union tree *, int, FILE *)); +static VOID dumpchr _ANSI_ARGS_((pchr, FILE *)); +#endif +/* === regc_nfa.c === */ +static struct nfa *newnfa _ANSI_ARGS_((struct vars *, struct colormap *, struct nfa *)); +static VOID freenfa _ANSI_ARGS_((struct nfa *)); +static struct state *newfstate _ANSI_ARGS_((struct nfa *, int flag)); +static struct state *newstate _ANSI_ARGS_((struct nfa *)); +static VOID dropstate _ANSI_ARGS_((struct nfa *, struct state *)); +static VOID freestate _ANSI_ARGS_((struct nfa *, struct state *)); +static VOID destroystate _ANSI_ARGS_((struct nfa *, struct state *)); +static VOID newarc _ANSI_ARGS_((struct nfa *, int, pcolor, struct state *, struct state *)); +static struct arc *allocarc _ANSI_ARGS_((struct nfa *, struct state *)); +static VOID freearc _ANSI_ARGS_((struct nfa *, struct arc *)); +static struct arc *findarc _ANSI_ARGS_((struct state *, int, pcolor)); +static VOID cparc _ANSI_ARGS_((struct nfa *, struct arc *, struct state *, struct state *)); +static VOID moveins _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID copyins _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID moveouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID copyouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID cloneouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *, int)); +static VOID delsub _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID deltraverse _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID dupnfa _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *, struct state *)); +static VOID duptraverse _ANSI_ARGS_((struct nfa *, struct state *, struct state *)); +static VOID cleartraverse _ANSI_ARGS_((struct nfa *, struct state *)); +static VOID specialcolors _ANSI_ARGS_((struct nfa *)); +static int optimize _ANSI_ARGS_((struct nfa *, FILE *)); +static VOID pullback _ANSI_ARGS_((struct nfa *, FILE *)); +static int pull _ANSI_ARGS_((struct nfa *, struct arc *)); +static VOID pushfwd _ANSI_ARGS_((struct nfa *, FILE *)); +static int push _ANSI_ARGS_((struct nfa *, struct arc *)); +#define INCOMPATIBLE 1 /* destroys arc */ +#define SATISFIED 2 /* constraint satisfied */ +#define COMPATIBLE 3 /* compatible but not satisfied yet */ +static int combine _ANSI_ARGS_((struct arc *, struct arc *)); +static VOID fixempties _ANSI_ARGS_((struct nfa *, FILE *)); +static int unempty _ANSI_ARGS_((struct nfa *, struct arc *)); +static VOID cleanup _ANSI_ARGS_((struct nfa *)); +static VOID markreachable _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *)); +static VOID markcanreach _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *)); +static int analyze _ANSI_ARGS_((struct nfa *)); +static VOID compact _ANSI_ARGS_((struct nfa *, struct cnfa *)); +static VOID carcsort _ANSI_ARGS_((struct carc *, struct carc *)); +static VOID freecnfa _ANSI_ARGS_((struct cnfa *)); +static VOID dumpnfa _ANSI_ARGS_((struct nfa *, FILE *)); +#ifdef REG_DEBUG +static VOID dumpstate _ANSI_ARGS_((struct state *, FILE *)); +static VOID dumparcs _ANSI_ARGS_((struct state *, FILE *)); +static int dumprarcs _ANSI_ARGS_((struct arc *, struct state *, FILE *, int)); +static VOID dumparc _ANSI_ARGS_((struct arc *, struct state *, FILE *)); +#endif +static VOID dumpcnfa _ANSI_ARGS_((struct cnfa *, FILE *)); +#ifdef REG_DEBUG +static VOID dumpcstate _ANSI_ARGS_((int, struct carc *, struct cnfa *, FILE *)); +#endif +/* === regc_cvec.c === */ +static struct cvec *newcvec _ANSI_ARGS_((int, int, int)); +static struct cvec *clearcvec _ANSI_ARGS_((struct cvec *)); +static VOID addchr _ANSI_ARGS_((struct cvec *, pchr)); +static VOID addrange _ANSI_ARGS_((struct cvec *, pchr, pchr)); +#ifdef USE_MCCE +static VOID addmcce _ANSI_ARGS_((struct cvec *, chr *, chr *)); +#endif +static int haschr _ANSI_ARGS_((struct cvec *, pchr)); +static struct cvec *getcvec _ANSI_ARGS_((struct vars *, int, int, int)); +static VOID freecvec _ANSI_ARGS_((struct cvec *)); +/* === regc_locale.c === */ +static int nmcces _ANSI_ARGS_((struct vars *)); +static int nleaders _ANSI_ARGS_((struct vars *)); +static struct cvec *allmcces _ANSI_ARGS_((struct vars *, struct cvec *)); +static celt element _ANSI_ARGS_((struct vars *, chr *, chr *)); +static struct cvec *range _ANSI_ARGS_((struct vars *, celt, celt, int)); +static int before _ANSI_ARGS_((celt, celt)); +static struct cvec *eclass _ANSI_ARGS_((struct vars *, celt, int)); +static struct cvec *cclass _ANSI_ARGS_((struct vars *, chr *, chr *, int)); +static struct cvec *allcases _ANSI_ARGS_((struct vars *, pchr)); +static int cmp _ANSI_ARGS_((CONST chr *, CONST chr *, size_t)); +static int casecmp _ANSI_ARGS_((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; + chr *now; /* scan pointer into string */ + chr *stop; /* end of string */ + chr *savenow; /* saved now and stop for "subroutine call" */ + 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 */ + struct cvec *cv; /* interface cvec */ + struct cvec *cv2; /* utility cvec */ + struct cvec *mcces; /* collating-element information */ +# define ISCELEADER(v,c) (v->mcces != NULL && haschr(v->mcces, (c))) + struct state *mccepbegin; /* in nfa, start of MCCE prototypes */ + struct state *mccepend; /* in nfa, end of MCCE prototypes */ + struct subre *lacons; /* lookahead-constraint vector */ + int nlacons; /* size of lacons */ + int usedshorter; /* used short-preferring quantifiers */ + int unmatchable; /* can never match */ +}; + +/* 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) ((c) ? 0 : ERR(e)) /* if condition false, error */ +#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' /* 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 struct fns functions = { + rfree, /* regfree insides */ +}; + + + +/* + - compile - compile regular expression + ^ int compile(regex_t *, CONST chr *, size_t, int); + */ +int +compile(re, string, len, flags) +regex_t *re; +CONST chr *string; +size_t len; +int flags; +{ + struct vars var; + struct vars *v = &var; + struct guts *g; + int i; + size_t j; + FILE *debug = (flags®_PROGRESS) ? stdout : (FILE *)NULL; +# define CNOERR() { if (ISERR()) return freev(v, v->err); } + + /* sanity checks */ + + if (re == NULL || string == NULL) + return REG_INVARG; + if ((flags®_QUOTE) && + (flags&(REG_ADVANCED|REG_EXPANDED|REG_NEWLINE))) + return REG_INVARG; + if (!(flags®_EXTENDED) && (flags®_ADVF)) + return REG_INVARG; + + /* initial setup (after which freev() is callable) */ + v->re = re; + v->now = (chr *)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->mcces = NULL; + v->lacons = NULL; + v->nlacons = 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 = 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(); + v->cv = newcvec(100, 20, 10); + if (v->cv == NULL) + return freev(v, REG_ESPACE); + i = nmcces(v); + if (i > 0) { + v->mcces = newcvec(nleaders(v), 0, i); + CNOERR(); + v->mcces = allmcces(v, v->mcces); + leaders(v, v->mcces); + } + CNOERR(); + + /* parsing */ + lexstart(v); /* also handles prefixes */ + if ((v->cflags®_NLSTOP) || (v->cflags®_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) { + dumpnfa(v->nfa, debug); + dumpst(v->tree, debug, 1); + } + v->usedshorter = 0; + v->unmatchable = 0; + optst(v, v->tree); + v->ntree = numst(v->tree, 1); + markst(v->tree); + cleanst(v); + if (debug != NULL) { + fprintf(debug, "-->\n"); + dumpst(v->tree, debug, 1); + } + + /* build compacted NFAs for tree, lacons, fast search */ + re->re_info |= nfatree(v, v->tree, debug); + if (debug != NULL) { + fprintf(debug, "---->\n"); + dumpst(v->tree, debug, 1); + } + CNOERR(); + if (re->re_info®_UIMPOSSIBLE) + v->unmatchable = 1; + assert(v->nlacons == 0 || v->lacons != NULL); + for (i = 1; i < v->nlacons; i++) + nfanode(v, &v->lacons[i], debug); + CNOERR(); + (DISCARD)optimize(v->nfa, debug); + CNOERR(); + makescan(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®_ICASE) ? casecmp : cmp; + g->lacons = v->lacons; + v->lacons = NULL; + g->nlacons = v->nlacons; + g->usedshorter = v->usedshorter; + g->unmatchable = v->unmatchable; + + if (flags®_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(v, wanted) +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 *, int); + */ +static int +freev(v, err) +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->mcces != NULL) + freecvec(v->mcces); + if (v->lacons != NULL) + freelacons(v->lacons, v->nlacons); + ERR(err); /* nop if err==0 */ + + return v->err; +} + +/* + - makescan - turn an NFA into a fast-scan NFA (implicit prepend of .*?) + * NFA must have been optimize()d already. + ^ static VOID makescan(struct vars *, struct nfa *); + */ +static VOID +makescan(v, nfa) +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 \Z* 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; + if (b != NULL) { /* must be split */ + s->tmp = slist; + slist = s; + } + } + + /* do the splits */ + for (s = slist; s != NULL; s = s2) { + s2 = newstate(nfa); + copyouts(nfa, s, s2); + 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->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(v, stopper, type, init, final) +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; /* 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 *, int, int, struct state *, + ^ struct state *, int); + */ +static struct subre * +parsebranch(v, stopper, type, left, right, partial) +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); + } + + 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(v, stopper, type, lp, rp, top) +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®_NLANCH) + ARCV(BEHIND, v->nlcolor); + NEXT(); + return; + break; + case '$': + ARCV('$', 1); + if (v->cflags®_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: /* 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; + 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®_ADVANCED) != REG_EXTENDED) { + ERR(REG_EPAREN); + return; + } + /* legal in EREs due to specification botch */ + NOTE(REG_UPBOTCH); + /* fallthrough into case PLAIN */ + 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®_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); + 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 = INFINITY; + qprefer = (v->nextvalue) ? LONGER : SHORTER; + NEXT(); + break; + case '+': + m = 1; + n = INFINITY; + 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 = INFINITY; + 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 + * + * ---> [s] ---prefix---> [begin] ---atom---> [end] ----rest---> [rp] + * / / + * [lp] ----> [s2] ----bypass--------------------- + * + * where bypass is an empty, and prefix is some repetitions of atom + */ + 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); /* and spots for prefix and bypass */ + s2 = newstate(v->nfa); + NOERR(); + EMPTYARC(lp, s); + EMPTYARC(lp, s2); + NOERR(); + + /* break remaining subRE into x{...} and what follows */ + t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp); + 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); + 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; first, turn x{0,...} into x{1,...}|empty */ + if (m == 0) { + EMPTYARC(s2, atom->end); /* the bypass */ + assert(PREF(qprefer) != 0); + f = COMBINE(qprefer, atom->flags); + t = subre(v, '|', f, lp, atom->end); + NOERR(); + t->left = atom; + t->right = subre(v, '|', PREF(f), s2, atom->end); + NOERR(); + t->right->left = subre(v, '=', 0, s2, atom->end); + NOERR(); + *atomp = t; + atomp = &t->left; + m = 1; + } + + /* deal with the rest of the quantifier */ + 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); + } else if (m == 1 && n == 1) { + /* no/vacuous quantifier: done */ + EMPTYARC(s, atom->begin); /* empty prefix */ + } else { + /* turn x{m,n} into x{m-1,n-1}x, with capturing */ + /* parens in only second x */ + dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin); + assert(m >= 1 && m != INFINITY && n >= 1); + repeat(v, s, atom->begin, m-1, (n == INFINITY) ? 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; + } + + /* and finally, look after that postponed recursion */ + t = top->right; + if (!(SEE('|') || SEE(stopper) || SEE(EOS))) + t->right = parsebranch(v, stopper, type, atom->end, rp, 1); + else { + EMPTYARC(atom->end, rp); + t->right = subre(v, '=', 0, atom->end, rp); + } + 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(v, dir, lp, rp) +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(v, dir, lp, rp) +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(v) +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 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(v, lp, rp, m, n) +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) == INFINITY) ? 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 *, struct state *, struct state *); + */ +static VOID +bracket(v, lp, rp) +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(v, lp, rp) +struct vars *v; +struct state *lp; +struct state *rp; +{ + struct state *left = newstate(v->nfa); + struct state *right = newstate(v->nfa); + struct state *s; + struct arc *a; /* arc from lp */ + struct arc *ba; /* arc from left, from bracket() */ + struct arc *pa; /* MCCE-prototype arc */ + color co; + chr *p; + int i; + + NOERR(); + bracket(v, left, right); + if (v->cflags®_NLSTOP) + newarc(v->nfa, PLAIN, v->nlcolor, left, right); + NOERR(); + + assert(lp->nouts == 0); /* all outarcs will be ours */ + + /* easy part of complementing */ + colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp); + NOERR(); + if (v->mcces == NULL) { /* no MCCEs -- we're done */ + dropstate(v->nfa, left); + assert(right->nins == 0); + freestate(v->nfa, right); + return; + } + + /* but complementing gets messy in the presence of MCCEs... */ + NOTE(REG_ULOCALE); + for (p = v->mcces->chrs, i = v->mcces->nchrs; i > 0; p++, i--) { + co = GETCOLOR(v->cm, *p); + a = findarc(lp, PLAIN, co); + ba = findarc(left, PLAIN, co); + if (ba == NULL) { + assert(a != NULL); + freearc(v->nfa, a); + } else { + assert(a == NULL); + } + s = newstate(v->nfa); + NOERR(); + newarc(v->nfa, PLAIN, co, lp, s); + NOERR(); + pa = findarc(v->mccepbegin, PLAIN, co); + assert(pa != NULL); + if (ba == NULL) { /* easy case, need all of them */ + cloneouts(v->nfa, pa->to, s, rp, PLAIN); + newarc(v->nfa, '$', 1, s, rp); + newarc(v->nfa, '$', 0, s, rp); + colorcomplement(v->nfa, v->cm, AHEAD, pa->to, s, rp); + } else { /* must be selective */ + if (findarc(ba->to, '$', 1) == NULL) { + newarc(v->nfa, '$', 1, s, rp); + newarc(v->nfa, '$', 0, s, rp); + colorcomplement(v->nfa, v->cm, AHEAD, pa->to, + s, rp); + } + for (pa = pa->to->outs; pa != NULL; pa = pa->outchain) + if (findarc(ba->to, PLAIN, pa->co) == NULL) + newarc(v->nfa, PLAIN, pa->co, s, rp); + if (s->nouts == 0) /* limit of selectivity: none */ + dropstate(v->nfa, s); /* frees arc too */ + } + NOERR(); + } + + delsub(v->nfa, left, right); + assert(left->nouts == 0); + freestate(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 *, struct state *, struct state *); + */ +static VOID +brackpart(v, lp, rp) +struct vars *v; +struct state *lp; +struct state *rp; +{ + celt startc; + celt endc; + struct cvec *cv; + chr *startp; + 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, not MCCE leader) */ + if (!SEE(RANGE) && !ISCELEADER(v, c[0])) { + 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®_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®_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[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®_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 chr *scanplain(struct vars *); + */ +static chr * /* just after end of sequence */ +scanplain(v) +struct vars *v; +{ + 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; +} + +/* + - leaders - process a cvec of collating elements to also include leaders + * Also gives all characters involved their own colors, which is almost + * certainly necessary, and sets up little disconnected subNFA. + ^ static VOID leaders(struct vars *, struct cvec *); + */ +static VOID +leaders(v, cv) +struct vars *v; +struct cvec *cv; +{ + int mcce; + chr *p; + chr leader; + struct state *s; + struct arc *a; + + v->mccepbegin = newstate(v->nfa); + v->mccepend = newstate(v->nfa); + NOERR(); + + for (mcce = 0; mcce < cv->nmcces; mcce++) { + p = cv->mcces[mcce]; + leader = *p; + if (!haschr(cv, leader)) { + addchr(cv, leader); + s = newstate(v->nfa); + newarc(v->nfa, PLAIN, subcolor(v->cm, leader), + v->mccepbegin, s); + okcolors(v->nfa, v->cm); + } else { + a = findarc(v->mccepbegin, PLAIN, + GETCOLOR(v->cm, leader)); + assert(a != NULL); + s = a->to; + assert(s != v->mccepend); + } + p++; + assert(*p != 0 && *(p+1) == 0); /* only 2-char MCCEs for now */ + newarc(v->nfa, PLAIN, subcolor(v->cm, *p), s, v->mccepend); + okcolors(v->nfa, v->cm); + } +} + +/* + - 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(v, c, lp, rp) +struct vars *v; +pchr c; +struct state *lp; +struct state *rp; +{ + if (!(v->cflags®_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 + * This one has to handle the messy cases, like MCCEs and MCCE leaders. + ^ static VOID dovec(struct vars *, struct cvec *, struct state *, + ^ struct state *); + */ +static VOID +dovec(v, cv, lp, rp) +struct vars *v; +struct cvec *cv; +struct state *lp; +struct state *rp; +{ + chr ch, from, to; + celt ce; + chr *p; + int i; + color co; + struct cvec *leads; + struct arc *a; + struct arc *pa; /* arc in prototype */ + struct state *s; + struct state *ps; /* state in prototype */ + + /* need a place to store leaders, if any */ + if (nmcces(v) > 0) { + assert(v->mcces != NULL); + if (v->cv2 == NULL || v->cv2->nchrs < v->mcces->nchrs) { + if (v->cv2 != NULL) + free(v->cv2); + v->cv2 = newcvec(v->mcces->nchrs, 0, v->mcces->nmcces); + NOERR(); + leads = v->cv2; + } else + leads = clearcvec(v->cv2); + } else + leads = NULL; + + /* first, get the ordinary characters out of the way */ + for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) { + ch = *p; + if (!ISCELEADER(v, ch)) + newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp); + else { + assert(singleton(v->cm, ch)); + assert(leads != NULL); + if (!haschr(leads, ch)) + addchr(leads, ch); + } + } + + /* and the ranges */ + for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) { + from = *p; + to = *(p+1); + while (from <= to && (ce = nextleader(v, from, to)) != NOCELT) { + if (from < ce) + subrange(v, from, ce - 1, lp, rp); + assert(singleton(v->cm, ce)); + assert(leads != NULL); + if (!haschr(leads, ce)) + addchr(leads, ce); + from = ce + 1; + } + if (from <= to) + subrange(v, from, to, lp, rp); + } + + if ((leads == NULL || leads->nchrs == 0) && cv->nmcces == 0) + return; + + /* deal with the MCCE leaders */ + NOTE(REG_ULOCALE); + for (p = leads->chrs, i = leads->nchrs; i > 0; p++, i--) { + co = GETCOLOR(v->cm, *p); + a = findarc(lp, PLAIN, co); + if (a != NULL) + s = a->to; + else { + s = newstate(v->nfa); + NOERR(); + newarc(v->nfa, PLAIN, co, lp, s); + NOERR(); + } + pa = findarc(v->mccepbegin, PLAIN, co); + assert(pa != NULL); + ps = pa->to; + newarc(v->nfa, '$', 1, s, rp); + newarc(v->nfa, '$', 0, s, rp); + colorcomplement(v->nfa, v->cm, AHEAD, ps, s, rp); + NOERR(); + } + + /* and the MCCEs */ + for (i = 0; i < cv->nmcces; i++) { + p = cv->mcces[i]; + assert(singleton(v->cm, *p)); + ch = *p++; + co = GETCOLOR(v->cm, ch); + a = findarc(lp, PLAIN, co); + if (a != NULL) + s = a->to; + else { + s = newstate(v->nfa); + NOERR(); + newarc(v->nfa, PLAIN, co, lp, s); + NOERR(); + } + assert(*p != 0); /* at least two chars */ + assert(singleton(v->cm, *p)); + ch = *p++; + co = GETCOLOR(v->cm, ch); + assert(*p == 0); /* and only two, for now */ + newarc(v->nfa, PLAIN, co, s, rp); + NOERR(); + } +} + +/* + - nextleader - find next MCCE leader within range + ^ static celt nextleader(struct vars *, pchr, pchr); + */ +static celt /* NOCELT means none */ +nextleader(v, from, to) +struct vars *v; +pchr from; +pchr to; +{ + int i; + chr *p; + chr ch; + celt it = NOCELT; + + if (v->mcces == NULL) + return it; + + for (i = v->mcces->nchrs, p = v->mcces->chrs; i > 0; i--, p++) { + ch = *p; + if (from <= ch && ch <= to) + if (it == NOCELT || ch < it) + it = ch; + } + return it; +} + +/* + - 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(v) +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; +} + +/* + - subre - allocate a subre + ^ static struct subre *subre(struct vars *, int, int, struct state *, + ^ struct state *); + */ +static struct subre * +subre(v, op, flags, begin, end) +struct vars *v; +int op; +int flags; +struct state *begin; +struct state *end; +{ + struct subre *ret; + + 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->retry = 0; + 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(v, sr) +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(v, sr) +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) { + sr->left = v->treefree; + v->treefree = sr; + } else + FREE(sr); +} + +/* + - optst - optimize a subRE subtree + ^ static VOID optst(struct vars *, struct subre *); + */ +static VOID +optst(v, t) +struct vars *v; +struct subre *t; +{ + if (t == NULL) + return; + + /* preference cleanup and analysis */ + if (t->flags&SHORTER) + v->usedshorter = 1; + + /* recurse through children */ + if (t->left != NULL) + optst(v, t->left); + if (t->right != NULL) + optst(v, t->right); +} + +/* + - numst - number tree nodes (assigning retry indexes) + ^ static int numst(struct subre *, int); + */ +static int /* next number */ +numst(t, start) +struct subre *t; +int start; /* starting point for subtree numbers */ +{ + int i; + + assert(t != NULL); + + i = start; + t->retry = (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 + ^ static VOID markst(struct subre *); + */ +static VOID +markst(t) +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(v) +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 int nfatree(struct vars *, struct subre *, FILE *); + */ +static int /* optimize results from top node */ +nfatree(v, t, f) +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 int nfanode(struct vars *, struct subre *, FILE *); + */ +static int /* optimize results */ +nfanode(v, t, f) +struct vars *v; +struct subre *t; +FILE *f; /* for debug output */ +{ + struct nfa *nfa; + int ret = 0; + + assert(t->begin != NULL); + + 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(v, begin, end, pos) +struct vars *v; +struct state *begin; +struct state *end; +int pos; +{ + int n; + struct subre *sub; + + if (v->nlacons == 0) { + v->lacons = (struct subre *)MALLOC(2 * sizeof(struct subre)); + n = 1; /* skip 0th */ + v->nlacons = 2; + } else { + v->lacons = (struct subre *)REALLOC(v->lacons, + (v->nlacons+1)*sizeof(struct subre)); + n = v->nlacons++; + } + if (v->lacons == NULL) { + ERR(REG_ESPACE); + return 0; + } + 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(subs, n) +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(re) +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; + 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); +} + +/* + - dump - dump an RE in human-readable form + ^ static VOID dump(regex_t *, FILE *); + */ +static VOID +dump(re, f) +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, "nsub %d, info 0%o, csize %d, ntree %d, usedshort %d\n", + re->re_nsub, re->re_info, re->re_csize, g->ntree, + g->usedshorter); + + dumpcolors(&g->cmap, f); + if (!NULLCNFA(g->search)) { + printf("search:\n"); + dumpcnfa(&g->search, f); + } + for (i = 1; i < g->nlacons; i++) { + fprintf(f, "la%d (%s):\n", i, + (g->lacons[i].subno) ? "positive" : "negative"); + dumpcnfa(&g->lacons[i].cnfa, f); + } + dumpst(g->tree, f, 0); +#endif +} + +/* + - dumpst - dump a subRE tree + ^ static VOID dumpst(struct subre *, FILE *, int); + */ +static VOID +dumpst(t, f, nfapresent) +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, 0); + fflush(f); +} + +/* + - stdump - recursive guts of dumpst + ^ static VOID stdump(struct subre *, FILE *, int, int); + */ +static VOID +stdump(t, f, nfapresent, level) +struct subre *t; +FILE *f; +int nfapresent; /* is the original NFA still around? */ +int level; +{ + int i; +# define RTSEP " " + + for (i = 0; i < level; i++) + fprintf(f, RTSEP); + fprintf(f, "%c (", t->op); + if (t->flags&LONGER) + fprintf(f, "L"); + if (t->flags&SHORTER) + fprintf(f, "S"); + if (t->flags&MIXED) + fprintf(f, "M"); + if (t->flags&CAP) + fprintf(f, "c"); + if (t->flags&BACKR) + fprintf(f, "b"); + if (!(t->flags&INUSE)) + fprintf(f, "!u"); + fprintf(f, ") r%d", t->retry); + if (t->subno != 0) + fprintf(f, " #%d", t->subno); + if (t->min != 1 || t->max != 1) { + fprintf(f, "{%d,", t->min); + if (t->max != INFINITY) + fprintf(f, "%d", t->max); + fprintf(f, "}"); + } + if (nfapresent) + fprintf(f, " %ld-%ld", (long)t->begin->no, (long)t->end->no); + if (!NULLCNFA(t->cnfa)) + fprintf(f, ":"); + fprintf(f, "\n"); + if (t->left != NULL) + stdump(t->left, f, nfapresent, level+1); + if (!NULLCNFA(t->cnfa)) + dumpcnfa(&t->cnfa, f); + if (t->right != NULL) + stdump(t->right, f, nfapresent, level+1); +} + +#include "regc_lex.c" +#include "regc_color.c" +#include "regc_nfa.c" +#include "regc_cvec.c" +#include "regc_locale.c" |