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author | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:56:22 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:56:22 (GMT) |
commit | d1a6de55efc90f190dee42ab8c4fa9070834e77d (patch) | |
tree | ec633f5608ef498bee52a5f42c12c49493ec8bf8 /tcl8.6/generic/regcomp.c | |
parent | 5514e37335c012cc70f5b9aee3cedfe3d57f583f (diff) | |
parent | 98acd3f494b28ddd8c345a2bb9311e41e2d56ddd (diff) | |
download | blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.zip blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.tar.gz blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.tar.bz2 |
Merge commit '98acd3f494b28ddd8c345a2bb9311e41e2d56ddd' as 'tcl8.6'
Diffstat (limited to 'tcl8.6/generic/regcomp.c')
-rw-r--r-- | tcl8.6/generic/regcomp.c | 2225 |
1 files changed, 2225 insertions, 0 deletions
diff --git a/tcl8.6/generic/regcomp.c b/tcl8.6/generic/regcomp.c new file mode 100644 index 0000000..211cd70 --- /dev/null +++ b/tcl8.6/generic/regcomp.c @@ -0,0 +1,2225 @@ +/* + * re_*comp and friends - compile REs + * This file #includes several others (see the bottom). + * + * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved. + * + * Development of this software was funded, in part, by Cray Research Inc., + * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics + * Corporation, none of whom are responsible for the results. The author + * thanks all of them. + * + * Redistribution and use in source and binary forms -- with or without + * modification -- are permitted for any purpose, provided that + * redistributions in source form retain this entire copyright notice and + * indicate the origin and nature of any modifications. + * + * I'd appreciate being given credit for this package in the documentation of + * software which uses it, but that is not a requirement. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL + * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include "regguts.h" + +/* + * forward declarations, up here so forward datatypes etc. are defined early + */ +/* =====^!^===== begin forwards =====^!^===== */ +/* automatically gathered by fwd; do not hand-edit */ +/* === regcomp.c === */ +int compile(regex_t *, const chr *, size_t, int); +static void moresubs(struct vars *, int); +static int freev(struct vars *, int); +static void makesearch(struct vars *, struct nfa *); +static struct subre *parse(struct vars *, int, int, struct state *, struct state *); +static struct subre *parsebranch(struct vars *, int, int, struct state *, struct state *, int); +static void parseqatom(struct vars *, int, int, struct state *, struct state *, struct subre *); +static void nonword(struct vars *, int, struct state *, struct state *); +static void word(struct vars *, int, struct state *, struct state *); +static int scannum(struct vars *); +static void repeat(struct vars *, struct state *, struct state *, int, int); +static void bracket(struct vars *, struct state *, struct state *); +static void cbracket(struct vars *, struct state *, struct state *); +static void brackpart(struct vars *, struct state *, struct state *); +static const chr *scanplain(struct vars *); +static void onechr(struct vars *, pchr, struct state *, struct state *); +static void dovec(struct vars *, struct cvec *, struct state *, struct state *); +static void wordchrs(struct vars *); +static struct subre *subre(struct vars *, int, int, struct state *, struct state *); +static void freesubre(struct vars *, struct subre *); +static void freesrnode(struct vars *, struct subre *); +static 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 *, FILE *); +static int newlacon(struct vars *, struct state *, struct state *, int); +static void freelacons(struct subre *, int); +static void rfree(regex_t *); +static void dump(regex_t *, FILE *); +static void dumpst(struct subre *, FILE *, int); +static void stdump(struct subre *, FILE *, int); +static const char *stid(struct subre *, char *, size_t); +/* === regc_lex.c === */ +static void lexstart(struct vars *); +static void prefixes(struct vars *); +static void lexnest(struct vars *, const chr *, const chr *); +static void lexword(struct vars *); +static int next(struct vars *); +static int lexescape(struct vars *); +static int lexdigits(struct vars *, int, int, int); +static int brenext(struct vars *, pchr); +static void skip(struct vars *); +static chr newline(NOPARMS); +static chr chrnamed(struct vars *, const chr *, const chr *, pchr); +/* === regc_color.c === */ +static void initcm(struct vars *, struct colormap *); +static void freecm(struct colormap *); +static void cmtreefree(struct colormap *, union tree *, int); +static color setcolor(struct colormap *, pchr, pcolor); +static color maxcolor(struct colormap *); +static color newcolor(struct colormap *); +static void freecolor(struct colormap *, pcolor); +static color pseudocolor(struct colormap *); +static color subcolor(struct colormap *, pchr c); +static color newsub(struct colormap *, pcolor); +static void subrange(struct vars *, pchr, pchr, struct state *, struct state *); +static void subblock(struct vars *, pchr, struct state *, struct state *); +static void okcolors(struct nfa *, struct colormap *); +static void colorchain(struct colormap *, struct arc *); +static void uncolorchain(struct colormap *, struct arc *); +static void rainbow(struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *); +static void colorcomplement(struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *); +#ifdef REG_DEBUG +static void dumpcolors(struct colormap *, FILE *); +static void fillcheck(struct colormap *, union tree *, int, FILE *); +static void dumpchr(pchr, FILE *); +#endif +/* === regc_nfa.c === */ +static struct nfa *newnfa(struct vars *, struct colormap *, struct nfa *); +static void freenfa(struct nfa *); +static struct state *newstate(struct nfa *); +static struct state *newfstate(struct nfa *, int flag); +static void dropstate(struct nfa *, struct state *); +static void freestate(struct nfa *, struct state *); +static void destroystate(struct nfa *, struct state *); +static void newarc(struct nfa *, int, pcolor, struct state *, struct state *); +static void createarc(struct nfa *, int, pcolor, struct state *, struct state *); +static struct arc *allocarc(struct nfa *, struct state *); +static void freearc(struct nfa *, struct arc *); +static void changearctarget(struct arc *, struct state *); +static int hasnonemptyout(struct state *); +static struct arc *findarc(struct state *, int, pcolor); +static void cparc(struct nfa *, struct arc *, struct state *, struct state *); +static void sortins(struct nfa *, struct state *); +static int sortins_cmp(const void *, const void *); +static void sortouts(struct nfa *, struct state *); +static int sortouts_cmp(const void *, const void *); +static void moveins(struct nfa *, struct state *, struct state *); +static void copyins(struct nfa *, struct state *, struct state *); +static void mergeins(struct nfa *, struct state *, struct arc **, int); +static void moveouts(struct nfa *, struct state *, struct state *); +static void copyouts(struct nfa *, struct state *, struct state *); +static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int); +static void delsub(struct nfa *, struct state *, struct state *); +static void deltraverse(struct nfa *, struct state *, struct state *); +static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *); +static void duptraverse(struct nfa *, struct state *, struct state *, int); +static void cleartraverse(struct nfa *, struct state *); +static void specialcolors(struct nfa *); +static long optimize(struct nfa *, FILE *); +static void pullback(struct nfa *, FILE *); +static int pull(struct nfa *, struct arc *, struct state **); +static void pushfwd(struct nfa *, FILE *); +static int push(struct nfa *, struct arc *, struct state **); +#define INCOMPATIBLE 1 /* destroys arc */ +#define SATISFIED 2 /* constraint satisfied */ +#define COMPATIBLE 3 /* compatible but not satisfied yet */ +static int combine(struct arc *, struct arc *); +static void fixempties(struct nfa *, FILE *); +static struct state *emptyreachable(struct nfa *, struct state *, + struct state *, struct arc **); +static int isconstraintarc(struct arc *); +static int hasconstraintout(struct state *); +static void fixconstraintloops(struct nfa *, FILE *); +static int findconstraintloop(struct nfa *, struct state *); +static void breakconstraintloop(struct nfa *, struct state *); +static void clonesuccessorstates(struct nfa *, struct state *, struct state *, + struct state *, struct arc *, char *, char *, int); +static void cleanup(struct nfa *); +static void markreachable(struct nfa *, struct state *, struct state *, struct state *); +static void markcanreach(struct nfa *, struct state *, struct state *, struct state *); +static long analyze(struct nfa *); +static void compact(struct nfa *, struct cnfa *); +static void carcsort(struct carc *, size_t); +static int carc_cmp(const void *, const void *); +static void freecnfa(struct cnfa *); +static void dumpnfa(struct nfa *, FILE *); +#ifdef REG_DEBUG +static void dumpstate(struct state *, FILE *); +static void dumparcs(struct state *, FILE *); +static void dumparc(struct arc *, struct state *, FILE *); +#endif +static void dumpcnfa(struct cnfa *, FILE *); +#ifdef REG_DEBUG +static void dumpcstate(int, struct cnfa *, FILE *); +#endif +/* === regc_cvec.c === */ +static struct cvec *clearcvec(struct cvec *); +static void addchr(struct cvec *, pchr); +static void addrange(struct cvec *, pchr, pchr); +static struct cvec *newcvec(int, int); +static struct cvec *getcvec(struct vars *, int, int); +static void freecvec(struct cvec *); +/* === regc_locale.c === */ +static celt element(struct vars *, const chr *, const chr *); +static struct cvec *range(struct vars *, celt, celt, int); +static int before(celt, celt); +static struct cvec *eclass(struct vars *, celt, int); +static struct cvec *cclass(struct vars *, const chr *, const chr *, int); +static struct cvec *allcases(struct vars *, pchr); +static int cmp(const chr *, const chr *, size_t); +static int casecmp(const chr *, const chr *, size_t); +/* automatically gathered by fwd; do not hand-edit */ +/* =====^!^===== end forwards =====^!^===== */ + +/* internal variables, bundled for easy passing around */ +struct vars { + regex_t *re; + const chr *now; /* scan pointer into string */ + const chr *stop; /* end of string */ + const chr *savenow; /* saved now and stop for "subroutine call" */ + const chr *savestop; + int err; /* error code (0 if none) */ + int cflags; /* copy of compile flags */ + int lasttype; /* type of previous token */ + int nexttype; /* type of next token */ + chr nextvalue; /* value (if any) of next token */ + int lexcon; /* lexical context type (see lex.c) */ + int nsubexp; /* subexpression count */ + struct subre **subs; /* subRE pointer vector */ + size_t nsubs; /* length of vector */ + struct subre *sub10[10]; /* initial vector, enough for most */ + struct nfa *nfa; /* the NFA */ + struct colormap *cm; /* character color map */ + color nlcolor; /* color of newline */ + struct state *wordchrs; /* state in nfa holding word-char outarcs */ + struct subre *tree; /* subexpression tree */ + struct subre *treechain; /* all tree nodes allocated */ + struct subre *treefree; /* any free tree nodes */ + int ntree; /* number of tree nodes, plus one */ + struct cvec *cv; /* interface cvec */ + struct cvec *cv2; /* utility cvec */ + struct subre *lacons; /* lookahead-constraint vector */ + int nlacons; /* size of lacons */ + size_t spaceused; /* approx. space used for compilation */ +}; + +/* parsing macros; most know that `v' is the struct vars pointer */ +#define NEXT() (next(v)) /* advance by one token */ +#define SEE(t) (v->nexttype == (t)) /* is next token this? */ +#define EAT(t) (SEE(t) && next(v)) /* if next is this, swallow it */ +#define VISERR(vv) ((vv)->err != 0)/* have we seen an error yet? */ +#define ISERR() VISERR(v) +#define VERR(vv,e) ((vv)->nexttype = EOS, \ + (vv)->err = ((vv)->err ? (vv)->err : (e))) +#define ERR(e) VERR(v, e) /* record an error */ +#define NOERR() {if (ISERR()) return;} /* if error seen, return */ +#define NOERRN() {if (ISERR()) return NULL;} /* NOERR with retval */ +#define NOERRZ() {if (ISERR()) return 0;} /* NOERR with retval */ +#define INSIST(c, e) do { if (!(c)) ERR(e); } while (0) /* error if c false */ +#define NOTE(b) (v->re->re_info |= (b)) /* note visible condition */ +#define EMPTYARC(x, y) newarc(v->nfa, EMPTY, 0, x, y) + +/* token type codes, some also used as NFA arc types */ +#define EMPTY 'n' /* no token present */ +#define EOS 'e' /* end of string */ +#define PLAIN 'p' /* ordinary character */ +#define DIGIT 'd' /* digit (in bound) */ +#define BACKREF 'b' /* back reference */ +#define COLLEL 'I' /* start of [. */ +#define ECLASS 'E' /* start of [= */ +#define CCLASS 'C' /* start of [: */ +#define END 'X' /* end of [. [= [: */ +#define RANGE 'R' /* - within [] which might be range delim. */ +#define LACON 'L' /* lookahead constraint subRE */ +#define AHEAD 'a' /* color-lookahead arc */ +#define BEHIND 'r' /* color-lookbehind arc */ +#define WBDRY 'w' /* word boundary constraint */ +#define NWBDRY 'W' /* non-word-boundary constraint */ +#define SBEGIN 'A' /* beginning of string (even if not BOL) */ +#define SEND 'Z' /* end of string (even if not EOL) */ +#define PREFER 'P' /* length preference */ + +/* is an arc colored, and hence on a color chain? */ +#define COLORED(a) \ + ((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND) + +/* static function list */ +static const struct fns functions = { + rfree, /* regfree insides */ +}; + +/* + - compile - compile regular expression + * Note: on failure, no resources remain allocated, so regfree() + * need not be applied to re. + ^ int compile(regex_t *, const chr *, size_t, int); + */ +int +compile( + regex_t *re, + const chr *string, + size_t len, + int flags) +{ + AllocVars(v); + struct guts *g; + int i; + size_t j; + FILE *debug = (flags®_PROGRESS) ? stdout : NULL; +#define CNOERR() { if (ISERR()) return freev(v, v->err); } + + /* + * Sanity checks. + */ + + if (re == NULL || string == NULL) { + FreeVars(v); + return REG_INVARG; + } + if ((flags®_QUOTE) && (flags&(REG_ADVANCED|REG_EXPANDED|REG_NEWLINE))) { + FreeVars(v); + return REG_INVARG; + } + if (!(flags®_EXTENDED) && (flags®_ADVF)) { + FreeVars(v); + return REG_INVARG; + } + + /* + * Initial setup (after which freev() is callable). + */ + + v->re = re; + v->now = string; + v->stop = v->now + len; + v->savenow = v->savestop = NULL; + v->err = 0; + v->cflags = flags; + v->nsubexp = 0; + v->subs = v->sub10; + v->nsubs = 10; + for (j = 0; j < v->nsubs; j++) { + v->subs[j] = NULL; + } + v->nfa = NULL; + v->cm = NULL; + v->nlcolor = COLORLESS; + v->wordchrs = NULL; + v->tree = NULL; + v->treechain = NULL; + v->treefree = NULL; + v->cv = NULL; + v->cv2 = NULL; + v->lacons = NULL; + v->nlacons = 0; + v->spaceused = 0; + re->re_magic = REMAGIC; + re->re_info = 0; /* bits get set during parse */ + re->re_csize = sizeof(chr); + re->re_guts = NULL; + re->re_fns = 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, NULL); + CNOERR(); + v->cv = newcvec(100, 20); + if (v->cv == NULL) { + return freev(v, REG_ESPACE); + } + + /* + * Parsing. + */ + + lexstart(v); /* also handles prefixes */ + if ((v->cflags®_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) { + fprintf(debug, "\n\n\n========= RAW ==========\n"); + dumpnfa(v->nfa, debug); + dumpst(v->tree, debug, 1); + } + optst(v, v->tree); + v->ntree = numst(v->tree, 1); + markst(v->tree); + cleanst(v); + if (debug != NULL) { + fprintf(debug, "\n\n\n========= TREE FIXED ==========\n"); + dumpst(v->tree, debug, 1); + } + + /* + * Build compacted NFAs for tree and lacons. + */ + + re->re_info |= nfatree(v, v->tree, debug); + CNOERR(); + assert(v->nlacons == 0 || v->lacons != NULL); + for (i = 1; i < v->nlacons; i++) { + if (debug != NULL) { + fprintf(debug, "\n\n\n========= LA%d ==========\n", i); + } + nfanode(v, &v->lacons[i], debug); + } + CNOERR(); + if (v->tree->flags&SHORTER) { + NOTE(REG_USHORTEST); + } + + /* + * Build compacted NFAs for tree, lacons, fast search. + */ + + if (debug != NULL) { + fprintf(debug, "\n\n\n========= SEARCH ==========\n"); + } + + /* + * Can sacrifice main NFA now, so use it as work area. + */ + + (DISCARD) optimize(v->nfa, debug); + CNOERR(); + makesearch(v, v->nfa); + CNOERR(); + compact(v->nfa, &g->search); + CNOERR(); + + /* + * Looks okay, package it up. + */ + + re->re_nsub = v->nsubexp; + v->re = NULL; /* freev no longer frees re */ + g->magic = GUTSMAGIC; + g->cflags = v->cflags; + g->info = re->re_info; + g->nsub = re->re_nsub; + g->tree = v->tree; + v->tree = NULL; + g->ntree = v->ntree; + g->compare = (v->cflags®_ICASE) ? casecmp : cmp; + g->lacons = v->lacons; + v->lacons = NULL; + g->nlacons = v->nlacons; + + 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( + struct vars *v, + int wanted) /* want enough room for this one */ +{ + struct subre **p; + size_t n; + + assert(wanted > 0 && (size_t)wanted >= v->nsubs); + n = (size_t)wanted * 3 / 2 + 1; + if (v->subs == v->sub10) { + p = (struct subre **) MALLOC(n * sizeof(struct subre *)); + if (p != NULL) { + memcpy(p, v->subs, v->nsubs * sizeof(struct subre *)); + } + } else { + p = (struct subre **) REALLOC(v->subs, n*sizeof(struct subre *)); + } + if (p == NULL) { + ERR(REG_ESPACE); + return; + } + + v->subs = p; + for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++) { + *p = NULL; + } + assert(v->nsubs == n); + assert((size_t)wanted < v->nsubs); +} + +/* + - freev - free vars struct's substructures where necessary + * Optionally does error-number setting, and always returns error code (if + * any), to make error-handling code terser. + ^ static int freev(struct vars *, int); + */ +static int +freev( + struct vars *v, + int err) +{ + register int ret; + + if (v->re != NULL) { + rfree(v->re); + } + if (v->subs != v->sub10) { + FREE(v->subs); + } + if (v->nfa != NULL) { + freenfa(v->nfa); + } + if (v->tree != NULL) { + freesubre(v, v->tree); + } + if (v->treechain != NULL) { + cleanst(v); + } + if (v->cv != NULL) { + freecvec(v->cv); + } + if (v->cv2 != NULL) { + freecvec(v->cv2); + } + if (v->lacons != NULL) { + freelacons(v->lacons, v->nlacons); + } + ERR(err); /* nop if err==0 */ + + ret = v->err; + FreeVars(v); + return ret; +} + +/* + - makesearch - turn an NFA into a search NFA (implicit prepend of .*?) + * NFA must have been optimize()d already. + ^ static void makesearch(struct vars *, struct nfa *); + */ +static void +makesearch( + struct vars *v, + struct nfa *nfa) +{ + struct arc *a, *b; + struct state *pre = nfa->pre; + struct state *s, *s2, *slist; + + /* + * No loops are needed if it's anchored. + */ + + for (a = pre->outs; a != NULL; a = a->outchain) { + assert(a->type == PLAIN); + if (a->co != nfa->bos[0] && a->co != nfa->bos[1]) { + break; + } + } + if (a != NULL) { + /* + * Add implicit .* in front. + */ + + rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre); + + /* + * And ^* and \A* too -- not always necessary, but harmless. + */ + + newarc(nfa, PLAIN, nfa->bos[0], pre, pre); + newarc(nfa, PLAIN, nfa->bos[1], pre, pre); + } + + /* + * Now here's the subtle part. Because many REs have no lookback + * constraints, often knowing when you were in the pre state tells you + * little; it's the next state(s) that are informative. But some of them + * may have other inarcs, i.e. it may be possible to make actual progress + * and then return to one of them. We must de-optimize such cases, + * splitting each such state into progress and no-progress states. + */ + + /* + * First, make a list of the states. + */ + + slist = NULL; + for (a=pre->outs ; a!=NULL ; a=a->outchain) { + s = a->to; + for (b=s->ins ; b!=NULL ; b=b->inchain) { + if (b->from != pre) { + break; + } + } + + /* + * We want to mark states as being in the list already by having non + * NULL tmp fields, but we can't just store the old slist value in tmp + * because that doesn't work for the first such state. Instead, the + * first list entry gets its own address in tmp. + */ + if (b != NULL && s->tmp == NULL) { + s->tmp = (slist != NULL) ? slist : s; + slist = s; + } + } + + /* + * Do the splits. + */ + + for (s=slist ; s!=NULL ; s=s2) { + s2 = newstate(nfa); + NOERR(); + copyouts(nfa, s, s2); + NOERR(); + for (a=s->ins ; a!=NULL ; a=b) { + b = a->inchain; + + if (a->from != pre) { + cparc(nfa, a, a->from, s2); + freearc(nfa, a); + } + } + s2 = (s->tmp != s) ? s->tmp : NULL; + s->tmp = NULL; /* clean up while we're at it */ + } +} + +/* + - parse - parse an RE + * This is actually just the top level, which parses a bunch of branches tied + * together with '|'. They appear in the tree as the left children of a chain + * of '|' subres. + ^ static struct subre *parse(struct vars *, int, int, struct state *, + ^ struct state *); + */ +static struct subre * +parse( + struct vars *v, + int stopper, /* EOS or ')' */ + int type, /* LACON (lookahead subRE) or PLAIN */ + struct state *init, /* initial state */ + struct state *final) /* final state */ +{ + struct state *left, *right; /* scaffolding for branch */ + struct subre *branches; /* top level */ + struct subre *branch; /* current branch */ + struct subre *t; /* temporary */ + int firstbranch; /* is this the first branch? */ + + assert(stopper == ')' || stopper == EOS); + + branches = subre(v, '|', LONGER, init, final); + NOERRN(); + branch = branches; + firstbranch = 1; + do { /* a branch */ + if (!firstbranch) { + /* + * Need a place to hang the branch. + */ + + branch->right = subre(v, '|', LONGER, init, final); + NOERRN(); + branch = branch->right; + } + firstbranch = 0; + left = newstate(v->nfa); + right = newstate(v->nfa); + NOERRN(); + EMPTYARC(init, left); + EMPTYARC(right, final); + NOERRN(); + branch->left = parsebranch(v, stopper, type, left, right, 0); + NOERRN(); + branch->flags |= UP(branch->flags | branch->left->flags); + if ((branch->flags &~ branches->flags) != 0) { /* new flags */ + for (t = branches; t != branch; t = t->right) { + t->flags |= branch->flags; + } + } + } while (EAT('|')); + assert(SEE(stopper) || SEE(EOS)); + + if (!SEE(stopper)) { + assert(stopper == ')' && SEE(EOS)); + ERR(REG_EPAREN); + } + + /* + * Optimize out simple cases. + */ + + if (branch == branches) { /* only one branch */ + assert(branch->right == NULL); + t = branch->left; + branch->left = NULL; + freesubre(v, branches); + branches = t; + } else if (!MESSY(branches->flags)) { /* no interesting innards */ + freesubre(v, branches->left); + branches->left = NULL; + freesubre(v, branches->right); + branches->right = NULL; + branches->op = '='; + } + + return branches; +} + +/* + - parsebranch - parse one branch of an RE + * This mostly manages concatenation, working closely with parseqatom(). + * Concatenated things are bundled up as much as possible, with separate + * ',' nodes introduced only when necessary due to substructure. + ^ static struct subre *parsebranch(struct vars *, int, int, struct state *, + ^ struct state *, int); + */ +static struct subre * +parsebranch( + struct vars *v, + int stopper, /* EOS or ')' */ + int type, /* LACON (lookahead subRE) or PLAIN */ + struct state *left, /* leftmost state */ + struct state *right, /* rightmost state */ + int partial) /* is this only part of a branch? */ +{ + struct state *lp; /* left end of current construct */ + int seencontent; /* is there anything in this branch yet? */ + struct subre *t; + + lp = left; + seencontent = 0; + t = subre(v, '=', 0, left, right); /* op '=' is tentative */ + NOERRN(); + while (!SEE('|') && !SEE(stopper) && !SEE(EOS)) { + if (seencontent) { /* implicit concat operator */ + lp = newstate(v->nfa); + NOERRN(); + moveins(v->nfa, right, lp); + } + seencontent = 1; + + /* NB, recursion in parseqatom() may swallow rest of branch */ + parseqatom(v, stopper, type, lp, right, t); + NOERRN(); + } + + if (!seencontent) { /* empty branch */ + if (!partial) { + NOTE(REG_UUNSPEC); + } + assert(lp == left); + EMPTYARC(left, right); + } + + return t; +} + +/* + - parseqatom - parse one quantified atom or constraint of an RE + * The bookkeeping near the end cooperates very closely with parsebranch(); in + * particular, it contains a recursion that can involve parsing the rest of + * the branch, making this function's name somewhat inaccurate. + ^ static void parseqatom(struct vars *, int, int, struct state *, + ^ struct state *, struct subre *); + */ +static void +parseqatom( + struct vars *v, + int stopper, /* EOS or ')' */ + int type, /* LACON (lookahead subRE) or PLAIN */ + struct state *lp, /* left state to hang it on */ + struct state *rp, /* right state to hang it on */ + struct subre *top) /* subtree top */ +{ + struct state *s; /* temporaries for new states */ + struct state *s2; +#define ARCV(t, val) newarc(v->nfa, t, val, lp, rp) + int m, n; + struct subre *atom; /* atom's subtree */ + struct subre *t; + int cap; /* capturing parens? */ + int pos; /* positive lookahead? */ + int subno; /* capturing-parens or backref number */ + int atomtype; + int qprefer; /* quantifier short/long preference */ + int f; + struct subre **atomp; /* where the pointer to atom is */ + + /* + * Initial bookkeeping. + */ + + atom = NULL; + assert(lp->nouts == 0); /* must string new code */ + assert(rp->nins == 0); /* between lp and rp */ + subno = 0; /* just to shut lint up */ + + /* + * An atom or constraint... + */ + + atomtype = v->nexttype; + switch (atomtype) { + /* first, constraints, which end by returning */ + case '^': + ARCV('^', 1); + if (v->cflags®_NLANCH) { + ARCV(BEHIND, v->nlcolor); + } + NEXT(); + return; + case '$': + ARCV('$', 1); + if (v->cflags®_NLANCH) { + ARCV(AHEAD, v->nlcolor); + } + NEXT(); + return; + case SBEGIN: + ARCV('^', 1); /* BOL */ + ARCV('^', 0); /* or BOS */ + NEXT(); + return; + case SEND: + ARCV('$', 1); /* EOL */ + ARCV('$', 0); /* or EOS */ + NEXT(); + return; + case '<': + wordchrs(v); /* does NEXT() */ + s = newstate(v->nfa); + NOERR(); + nonword(v, BEHIND, lp, s); + word(v, AHEAD, s, rp); + return; + case '>': + wordchrs(v); /* does NEXT() */ + s = newstate(v->nfa); + NOERR(); + word(v, BEHIND, lp, s); + nonword(v, AHEAD, s, rp); + return; + case WBDRY: + wordchrs(v); /* does NEXT() */ + s = newstate(v->nfa); + NOERR(); + nonword(v, BEHIND, lp, s); + word(v, AHEAD, s, rp); + s = newstate(v->nfa); + NOERR(); + word(v, BEHIND, lp, s); + nonword(v, AHEAD, s, rp); + return; + case NWBDRY: + wordchrs(v); /* does NEXT() */ + s = newstate(v->nfa); + NOERR(); + word(v, BEHIND, lp, s); + word(v, AHEAD, s, rp); + s = newstate(v->nfa); + NOERR(); + nonword(v, BEHIND, lp, s); + nonword(v, AHEAD, s, rp); + return; + case LACON: /* lookahead constraint */ + pos = v->nextvalue; + NEXT(); + s = newstate(v->nfa); + s2 = newstate(v->nfa); + NOERR(); + t = parse(v, ')', LACON, s, s2); + freesubre(v, t); /* internal structure irrelevant */ + assert(SEE(')') || ISERR()); + NEXT(); + n = newlacon(v, s, s2, pos); + NOERR(); + ARCV(LACON, n); + return; + + /* + * Then errors, to get them out of the way. + */ + + case '*': + case '+': + case '?': + case '{': + ERR(REG_BADRPT); + return; + default: + ERR(REG_ASSERT); + return; + + /* + * Then plain characters, and minor variants on that theme. + */ + + case ')': /* unbalanced paren */ + if ((v->cflags®_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); + NOERR(); + subno = v->nextvalue; + atom->subno = subno; + EMPTYARC(lp, rp); /* temporarily, so there's something */ + NEXT(); + break; + } + + /* + * ...and an atom may be followed by a quantifier. + */ + + switch (v->nexttype) { + case '*': + m = 0; + n = DUPINF; + qprefer = (v->nextvalue) ? LONGER : SHORTER; + NEXT(); + break; + case '+': + m = 1; + n = DUPINF; + qprefer = (v->nextvalue) ? LONGER : SHORTER; + NEXT(); + break; + case '?': + m = 0; + n = 1; + qprefer = (v->nextvalue) ? LONGER : SHORTER; + NEXT(); + break; + case '{': + NEXT(); + m = scannum(v); + if (EAT(',')) { + if (SEE(DIGIT)) { + n = scannum(v); + } else { + n = DUPINF; + } + if (m > n) { + ERR(REG_BADBR); + return; + } + + /* + * {m,n} exercises preference, even if it's {m,m} + */ + + qprefer = (v->nextvalue) ? LONGER : SHORTER; + } else { + n = m; + /* + * {m} passes operand's preference through. + */ + + qprefer = 0; + } + if (!SEE('}')) { /* catches errors too */ + ERR(REG_BADBR); + return; + } + NEXT(); + break; + default: /* no quantifier */ + m = n = 1; + qprefer = 0; + break; + } + + /* + * Annoying special case: {0} or {0,0} cancels everything. + */ + + if (m == 0 && n == 0) { + if (atom != NULL) { + freesubre(v, atom); + } + if (atomtype == '(') { + v->subs[subno] = NULL; + } + delsub(v->nfa, lp, rp); + EMPTYARC(lp, rp); + return; + } + + /* + * If not a messy case, avoid hard part. + */ + + assert(!MESSY(top->flags)); + f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0); + if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f))) { + if (!(m == 1 && n == 1)) { + repeat(v, lp, rp, m, n); + } + if (atom != NULL) { + freesubre(v, atom); + } + top->flags = f; + return; + } + + /* + * hard part: something messy + * That is, capturing parens, back reference, short/long clash, or an atom + * with substructure containing one of those. + */ + + /* + * Now we'll need a subre for the contents even if they're boring. + */ + + if (atom == NULL) { + atom = subre(v, '=', 0, lp, rp); + NOERR(); + } + + /* + * Prepare a general-purpose state skeleton. + * + * In the no-backrefs case, we want this: + * + * [lp] ---> [s] ---prefix---> [begin] ---atom---> [end] ---rest---> [rp] + * + * where prefix is some repetitions of atom. In the general case we need + * + * [lp] ---> [s] ---iterator---> [s2] ---rest---> [rp] + * + * where the iterator wraps around [begin] ---atom---> [end] + * + * We make the s state here for both cases; s2 is made below if needed + */ + + s = newstate(v->nfa); /* first, new endpoints for the atom */ + s2 = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, lp, s); + moveins(v->nfa, rp, s2); + NOERR(); + atom->begin = s; + atom->end = s2; + s = newstate(v->nfa); /* set up starting state */ + NOERR(); + EMPTYARC(lp, s); + NOERR(); + + /* + * Break remaining subRE into x{...} and what follows. + */ + + t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp); + NOERR(); + t->left = atom; + atomp = &t->left; + + /* + * Here we should recurse... but we must postpone that to the end. + */ + + /* + * Split top into prefix and remaining. + */ + + assert(top->op == '=' && top->left == NULL && top->right == NULL); + top->left = subre(v, '=', top->flags, top->begin, lp); + NOERR(); + top->op = '.'; + top->right = t; + + /* + * If it's a backref, now is the time to replicate the subNFA. + */ + + if (atomtype == BACKREF) { + assert(atom->begin->nouts == 1); /* just the EMPTY */ + delsub(v->nfa, atom->begin, atom->end); + assert(v->subs[subno] != NULL); + + /* + * And here's why the recursion got postponed: it must wait until the + * skeleton is filled in, because it may hit a backref that wants to + * copy the filled-in skeleton. + */ + + dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end, + atom->begin, atom->end); + NOERR(); + } + + /* + * It's quantifier time. If the atom is just a backref, we'll let it deal + * with quantifiers internally. + */ + + if (atomtype == BACKREF) { + /* + * Special case: backrefs have internal quantifiers. + */ + + EMPTYARC(s, atom->begin); /* empty prefix */ + + /* + * Just stuff everything into atom. + */ + + repeat(v, atom->begin, atom->end, m, n); + atom->min = (short) m; + atom->max = (short) n; + atom->flags |= COMBINE(qprefer, atom->flags); + /* rest of branch can be strung starting from atom->end */ + s2 = atom->end; + } else if (m == 1 && n == 1) { + /* + * No/vacuous quantifier: done. + */ + + EMPTYARC(s, atom->begin); /* empty prefix */ + /* rest of branch can be strung starting from atom->end */ + s2 = atom->end; + } else if (m > 0 && !(atom->flags & BACKR)) { + /* + * If there's no backrefs involved, we can turn x{m,n} into + * x{m-1,n-1}x, with capturing parens in only the second x. This + * is valid because we only care about capturing matches from the + * final iteration of the quantifier. It's a win because we can + * implement the backref-free left side as a plain DFA node, since + * we don't really care where its submatches are. + */ + + dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin); + assert(m >= 1 && m != DUPINF && n >= 1); + repeat(v, s, atom->begin, m-1, (n == DUPINF) ? n : n-1); + f = COMBINE(qprefer, atom->flags); + t = subre(v, '.', f, s, atom->end); /* prefix and atom */ + NOERR(); + t->left = subre(v, '=', PREF(f), s, atom->begin); + NOERR(); + t->right = atom; + *atomp = t; + /* rest of branch can be strung starting from atom->end */ + s2 = atom->end; + } else { + /* general case: need an iteration node */ + s2 = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, atom->end, s2); + NOERR(); + dupnfa(v->nfa, atom->begin, atom->end, s, s2); + repeat(v, s, s2, m, n); + f = COMBINE(qprefer, atom->flags); + t = subre(v, '*', f, s, s2); + NOERR(); + t->min = (short) m; + t->max = (short) n; + t->left = atom; + *atomp = t; + /* rest of branch is to be strung from iteration's end state */ + } + + /* + * And finally, look after that postponed recursion. + */ + + t = top->right; + if (!(SEE('|') || SEE(stopper) || SEE(EOS))) { + t->right = parsebranch(v, stopper, type, s2, rp, 1); + } else { + EMPTYARC(s2, rp); + t->right = subre(v, '=', 0, s2, rp); + } + NOERR(); + assert(SEE('|') || SEE(stopper) || SEE(EOS)); + t->flags |= COMBINE(t->flags, t->right->flags); + top->flags |= COMBINE(top->flags, t->flags); +} + +/* + - nonword - generate arcs for non-word-character ahead or behind + ^ static void nonword(struct vars *, int, struct state *, struct state *); + */ +static void +nonword( + struct vars *v, + int dir, /* AHEAD or BEHIND */ + struct state *lp, + struct state *rp) +{ + int anchor = (dir == AHEAD) ? '$' : '^'; + + assert(dir == AHEAD || dir == BEHIND); + newarc(v->nfa, anchor, 1, lp, rp); + newarc(v->nfa, anchor, 0, lp, rp); + colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp); + /* (no need for special attention to \n) */ +} + +/* + - word - generate arcs for word character ahead or behind + ^ static void word(struct vars *, int, struct state *, struct state *); + */ +static void +word( + struct vars *v, + int dir, /* AHEAD or BEHIND */ + struct state *lp, + struct state *rp) +{ + assert(dir == AHEAD || dir == BEHIND); + cloneouts(v->nfa, v->wordchrs, lp, rp, dir); + /* (no need for special attention to \n) */ +} + +/* + - scannum - scan a number + ^ static int scannum(struct vars *); + */ +static int /* value, <= DUPMAX */ +scannum( + struct vars *v) +{ + int n = 0; + + while (SEE(DIGIT) && n < DUPMAX) { + n = n*10 + v->nextvalue; + NEXT(); + } + if (SEE(DIGIT) || n > DUPMAX) { + ERR(REG_BADBR); + return 0; + } + return n; +} + +/* + - repeat - replicate subNFA for quantifiers + * The sub-NFA strung from lp to rp is modified to represent m to n + * repetitions of its initial contents. + * The duplication sequences used here are chosen carefully so that any + * pointers starting out pointing into the subexpression end up pointing into + * the last occurrence. (Note that it may not be strung between the same left + * and right end states, however!) This used to be important for the subRE + * tree, although the important bits are now handled by the in-line code in + * parse(), and when this is called, it doesn't matter any more. + ^ static void repeat(struct vars *, struct state *, struct state *, int, int); + */ +static void +repeat( + struct vars *v, + struct state *lp, + struct state *rp, + int m, + int n) +{ +#define SOME 2 +#define INF 3 +#define PAIR(x, y) ((x)*4 + (y)) +#define REDUCE(x) ( ((x) == DUPINF) ? INF : (((x) > 1) ? SOME : (x)) ) + const int rm = REDUCE(m); + const int rn = REDUCE(n); + struct state *s, *s2; + + switch (PAIR(rm, rn)) { + case PAIR(0, 0): /* empty string */ + delsub(v->nfa, lp, rp); + EMPTYARC(lp, rp); + break; + case PAIR(0, 1): /* do as x| */ + EMPTYARC(lp, rp); + break; + case PAIR(0, SOME): /* do as x{1,n}| */ + repeat(v, lp, rp, 1, n); + NOERR(); + EMPTYARC(lp, rp); + break; + case PAIR(0, INF): /* loop x around */ + s = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, lp, s); + moveins(v->nfa, rp, s); + EMPTYARC(lp, s); + EMPTYARC(s, rp); + break; + case PAIR(1, 1): /* no action required */ + break; + case PAIR(1, SOME): /* do as x{0,n-1}x = (x{1,n-1}|)x */ + s = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, lp, s); + dupnfa(v->nfa, s, rp, lp, s); + NOERR(); + repeat(v, lp, s, 1, n-1); + NOERR(); + EMPTYARC(lp, s); + break; + case PAIR(1, INF): /* add loopback arc */ + s = newstate(v->nfa); + s2 = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, lp, s); + moveins(v->nfa, rp, s2); + EMPTYARC(lp, s); + EMPTYARC(s2, rp); + EMPTYARC(s2, s); + break; + case PAIR(SOME, SOME): /* do as x{m-1,n-1}x */ + s = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, lp, s); + dupnfa(v->nfa, s, rp, lp, s); + NOERR(); + repeat(v, lp, s, m-1, n-1); + break; + case PAIR(SOME, INF): /* do as x{m-1,}x */ + s = newstate(v->nfa); + NOERR(); + moveouts(v->nfa, lp, s); + dupnfa(v->nfa, s, rp, lp, s); + NOERR(); + repeat(v, lp, s, m-1, n); + break; + default: + ERR(REG_ASSERT); + break; + } +} + +/* + - bracket - handle non-complemented bracket expression + * Also called from cbracket for complemented bracket expressions. + ^ static void bracket(struct vars *, struct state *, struct state *); + */ +static void +bracket( + struct vars *v, + struct state *lp, + struct state *rp) +{ + assert(SEE('[')); + NEXT(); + while (!SEE(']') && !SEE(EOS)) { + brackpart(v, lp, rp); + } + assert(SEE(']') || ISERR()); + okcolors(v->nfa, v->cm); +} + +/* + - cbracket - handle complemented bracket expression + * We do it by calling bracket() with dummy endpoints, and then complementing + * the result. The alternative would be to invoke rainbow(), and then delete + * arcs as the b.e. is seen... but that gets messy. + ^ static void cbracket(struct vars *, struct state *, struct state *); + */ +static void +cbracket( + struct vars *v, + struct state *lp, + struct state *rp) +{ + struct state *left = newstate(v->nfa); + struct state *right = newstate(v->nfa); + + NOERR(); + bracket(v, left, right); + if (v->cflags®_NLSTOP) { + newarc(v->nfa, PLAIN, v->nlcolor, left, right); + } + NOERR(); + + assert(lp->nouts == 0); /* all outarcs will be ours */ + + /* + * Easy part of complementing, and all there is to do since the MCCE code + * was removed. + */ + + colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp); + NOERR(); + dropstate(v->nfa, left); + assert(right->nins == 0); + freestate(v->nfa, right); + return; +} + +/* + - brackpart - handle one item (or range) within a bracket expression + ^ static void brackpart(struct vars *, struct state *, struct state *); + */ +static void +brackpart( + struct vars *v, + struct state *lp, + struct state *rp) +{ + celt startc, endc; + struct cvec *cv; + const chr *startp, *endp; + chr c; + + /* + * Parse something, get rid of special cases, take shortcuts. + */ + + switch (v->nexttype) { + case RANGE: /* a-b-c or other botch */ + ERR(REG_ERANGE); + return; + break; + case PLAIN: + c = v->nextvalue; + NEXT(); + + /* + * Shortcut for ordinary chr (not range). + */ + + if (!SEE(RANGE)) { + onechr(v, c, lp, rp); + return; + } + startc = element(v, &c, &c+1); + NOERR(); + break; + case COLLEL: + startp = v->now; + endp = scanplain(v); + INSIST(startp < endp, REG_ECOLLATE); + NOERR(); + startc = element(v, startp, endp); + NOERR(); + break; + case ECLASS: + startp = v->now; + endp = scanplain(v); + INSIST(startp < endp, REG_ECOLLATE); + NOERR(); + startc = element(v, startp, endp); + NOERR(); + cv = eclass(v, startc, (v->cflags®_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 = 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 const chr *scanplain(struct vars *); + */ +static const chr * /* just after end of sequence */ +scanplain( + struct vars *v) +{ + const chr *endp; + + assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS)); + NEXT(); + + endp = v->now; + while (SEE(PLAIN)) { + endp = v->now; + NEXT(); + } + + assert(SEE(END) || ISERR()); + NEXT(); + + return endp; +} + +/* + - onechr - fill in arcs for a plain character, and possible case complements + * This is mostly a shortcut for efficient handling of the common case. + ^ static void onechr(struct vars *, pchr, struct state *, struct state *); + */ +static void +onechr( + struct vars *v, + pchr c, + struct state *lp, + struct state *rp) +{ + if (!(v->cflags®_ICASE)) { + newarc(v->nfa, PLAIN, subcolor(v->cm, c), lp, rp); + return; + } + + /* + * Rats, need general case anyway... + */ + + dovec(v, allcases(v, c), lp, rp); +} + +/* + - dovec - fill in arcs for each element of a cvec + ^ static void dovec(struct vars *, struct cvec *, struct state *, + ^ struct state *); + */ +static void +dovec( + struct vars *v, + struct cvec *cv, + struct state *lp, + struct state *rp) +{ + chr ch, from, to; + const chr *p; + int i; + + for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) { + ch = *p; + newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp); + } + + for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) { + from = *p; + to = *(p+1); + if (from <= to) { + subrange(v, from, to, lp, rp); + } + } + +} + +/* + - wordchrs - set up word-chr list for word-boundary stuff, if needed + * The list is kept as a bunch of arcs between two dummy states; it's disposed + * of by the unreachable-states sweep in NFA optimization. Does NEXT(). Must + * not be called from any unusual lexical context. This should be reconciled + * with the \w etc. handling in lex.c, and should be cleaned up to reduce + * dependencies on input scanning. + ^ static void wordchrs(struct vars *); + */ +static void +wordchrs( + struct vars *v) +{ + struct state *left, *right; + + if (v->wordchrs != NULL) { + NEXT(); /* for consistency */ + return; + } + + left = newstate(v->nfa); + right = newstate(v->nfa); + NOERR(); + + /* + * Fine point: implemented with [::], and lexer will set REG_ULOCALE. + */ + + lexword(v); + NEXT(); + assert(v->savenow != NULL && SEE('[')); + bracket(v, left, right); + assert((v->savenow != NULL && SEE(']')) || ISERR()); + NEXT(); + NOERR(); + v->wordchrs = left; +} + +/* + - subre - allocate a subre + ^ static struct subre *subre(struct vars *, int, int, struct state *, + ^ struct state *); + */ +static struct subre * +subre( + struct vars *v, + int op, + int flags, + struct state *begin, + struct state *end) +{ + struct subre *ret = v->treefree; + + if (ret != NULL) { + v->treefree = ret->left; + } else { + ret = (struct subre *) MALLOC(sizeof(struct subre)); + if (ret == NULL) { + ERR(REG_ESPACE); + return NULL; + } + ret->chain = v->treechain; + v->treechain = ret; + } + + assert(strchr("=b|.*(", op) != NULL); + + ret->op = op; + ret->flags = flags; + ret->id = 0; /* will be assigned later */ + ret->subno = 0; + ret->min = ret->max = 1; + ret->left = NULL; + ret->right = NULL; + ret->begin = begin; + ret->end = end; + ZAPCNFA(ret->cnfa); + + return ret; +} + +/* + - freesubre - free a subRE subtree + ^ static void freesubre(struct vars *, struct subre *); + */ +static void +freesubre( + struct vars *v, /* might be NULL */ + struct subre *sr) +{ + if (sr == NULL) { + return; + } + + if (sr->left != NULL) { + freesubre(v, sr->left); + } + if (sr->right != NULL) { + freesubre(v, sr->right); + } + + freesrnode(v, sr); +} + +/* + - freesrnode - free one node in a subRE subtree + ^ static void freesrnode(struct vars *, struct subre *); + */ +static void +freesrnode( + struct vars *v, /* might be NULL */ + struct subre *sr) +{ + if (sr == NULL) { + return; + } + + if (!NULLCNFA(sr->cnfa)) { + freecnfa(&sr->cnfa); + } + sr->flags = 0; + + if (v != NULL && v->treechain != NULL) { + /* we're still parsing, maybe we can reuse the subre */ + sr->left = v->treefree; + v->treefree = sr; + } else { + FREE(sr); + } +} + +/* + - optst - optimize a subRE subtree + ^ static void optst(struct vars *, struct subre *); + */ +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 numst(struct subre *, int); + */ +static int /* next number */ +numst( + struct subre *t, + int start) /* starting point for subtree numbers */ +{ + int i; + + assert(t != NULL); + + i = start; + t->id = (short) i++; + if (t->left != NULL) { + i = numst(t->left, i); + } + if (t->right != NULL) { + i = numst(t->right, i); + } + return i; +} + +/* + - markst - mark tree nodes as INUSE + * Note: this is a great deal more subtle than it looks. During initial + * parsing of a regex, all subres are linked into the treechain list; + * discarded ones are also linked into the treefree list for possible reuse. + * After we are done creating all subres required for a regex, we run markst() + * then cleanst(), which results in discarding all subres not reachable from + * v->tree. We then clear v->treechain, indicating that subres must be found + * by descending from v->tree. This changes the behavior of freesubre(): it + * will henceforth FREE() unwanted subres rather than sticking them into the + * treefree list. (Doing that any earlier would result in dangling links in + * the treechain list.) This all means that freev() will clean up correctly + * if invoked before or after markst()+cleanst(); but it would not work if + * called partway through this state conversion, so we mustn't error out + * in or between these two functions. + ^ static void markst(struct subre *); + */ +static void +markst( + struct subre *t) +{ + assert(t != NULL); + + t->flags |= INUSE; + if (t->left != NULL) { + markst(t->left); + } + if (t->right != NULL) { + markst(t->right); + } +} + +/* + - cleanst - free any tree nodes not marked INUSE + ^ static void cleanst(struct vars *); + */ +static void +cleanst( + struct vars *v) +{ + struct subre *t; + struct subre *next; + + for (t = v->treechain; t != NULL; t = next) { + next = t->chain; + if (!(t->flags&INUSE)) { + FREE(t); + } + } + v->treechain = NULL; + v->treefree = NULL; /* just on general principles */ +} + +/* + - nfatree - turn a subRE subtree into a tree of compacted NFAs + ^ static long nfatree(struct vars *, struct subre *, FILE *); + */ +static long /* optimize results from top node */ +nfatree( + struct vars *v, + struct subre *t, + FILE *f) /* for debug output */ +{ + assert(t != NULL && t->begin != NULL); + + if (t->left != NULL) { + (DISCARD) nfatree(v, t->left, f); + } + if (t->right != NULL) { + (DISCARD) nfatree(v, t->right, f); + } + + return nfanode(v, t, f); +} + +/* + - nfanode - do one NFA for nfatree + ^ static long nfanode(struct vars *, struct subre *, FILE *); + */ +static long /* optimize results */ +nfanode( + struct vars *v, + struct subre *t, + FILE *f) /* for debug output */ +{ + struct nfa *nfa; + long ret = 0; + char idbuf[50]; + + assert(t->begin != NULL); + + if (f != NULL) { + fprintf(f, "\n\n\n========= TREE NODE %s ==========\n", + stid(t, idbuf, sizeof(idbuf))); + } + nfa = newnfa(v, v->cm, v->nfa); + NOERRZ(); + dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final); + if (!ISERR()) { + specialcolors(nfa); + ret = optimize(nfa, f); + } + if (!ISERR()) { + compact(nfa, &t->cnfa); + } + + freenfa(nfa); + return ret; +} + +/* + - newlacon - allocate a lookahead-constraint subRE + ^ static int newlacon(struct vars *, struct state *, struct state *, int); + */ +static int /* lacon number */ +newlacon( + struct vars *v, + struct state *begin, + struct state *end, + int pos) +{ + int n; + struct subre *newlacons; + struct subre *sub; + + if (v->nlacons == 0) { + n = 1; /* skip 0th */ + newlacons = (struct subre *) MALLOC(2 * sizeof(struct subre)); + } else { + n = v->nlacons; + newlacons = (struct subre *) REALLOC(v->lacons, + (n + 1) * sizeof(struct subre)); + } + + if (newlacons == NULL) { + ERR(REG_ESPACE); + return 0; + } + + v->lacons = newlacons; + v->nlacons = n + 1; + sub = &v->lacons[n]; + sub->begin = begin; + sub->end = end; + sub->subno = pos; + ZAPCNFA(sub->cnfa); + return n; +} + +/* + - freelacons - free lookahead-constraint subRE vector + ^ static void freelacons(struct subre *, int); + */ +static void +freelacons( + struct subre *subs, + int n) +{ + struct subre *sub; + int i; + + assert(n > 0); + for (sub=subs+1, i=n-1; i>0; sub++, i--) { /* no 0th */ + if (!NULLCNFA(sub->cnfa)) { + freecnfa(&sub->cnfa); + } + } + FREE(subs); +} + +/* + - rfree - free a whole RE (insides of regfree) + ^ static void rfree(regex_t *); + */ +static void +rfree( + regex_t *re) +{ + struct guts *g; + + if (re == NULL || re->re_magic != REMAGIC) { + return; + } + + re->re_magic = 0; /* invalidate RE */ + g = (struct guts *) re->re_guts; + re->re_guts = NULL; + re->re_fns = NULL; + if (g != NULL) { + g->magic = 0; + freecm(&g->cmap); + if (g->tree != NULL) { + freesubre(NULL, g->tree); + } + if (g->lacons != NULL) { + freelacons(g->lacons, g->nlacons); + } + if (!NULLCNFA(g->search)) { + freecnfa(&g->search); + } + FREE(g); + } +} + +/* + - dump - dump an RE in human-readable form + ^ static void dump(regex_t *, FILE *); + */ +static void +dump( + regex_t *re, + FILE *f) +{ +#ifdef REG_DEBUG + struct guts *g; + int i; + + if (re->re_magic != REMAGIC) { + fprintf(f, "bad magic number (0x%x not 0x%x)\n", + re->re_magic, REMAGIC); + } + if (re->re_guts == NULL) { + fprintf(f, "NULL guts!!!\n"); + return; + } + g = (struct guts *) re->re_guts; + if (g->magic != GUTSMAGIC) { + fprintf(f, "bad guts magic number (0x%x not 0x%x)\n", + g->magic, GUTSMAGIC); + } + + fprintf(f, "\n\n\n========= DUMP ==========\n"); + fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n", + (int) re->re_nsub, re->re_info, re->re_csize, g->ntree); + + dumpcolors(&g->cmap, f); + if (!NULLCNFA(g->search)) { + fprintf(f, "\nsearch:\n"); + dumpcnfa(&g->search, f); + } + for (i = 1; i < g->nlacons; i++) { + fprintf(f, "\nla%d (%s):\n", i, + (g->lacons[i].subno) ? "positive" : "negative"); + dumpcnfa(&g->lacons[i].cnfa, f); + } + fprintf(f, "\n"); + dumpst(g->tree, f, 0); +#endif +} + +/* + - dumpst - dump a subRE tree + ^ static void dumpst(struct subre *, FILE *, int); + */ +static void +dumpst( + struct subre *t, + FILE *f, + int nfapresent) /* is the original NFA still around? */ +{ + if (t == NULL) { + fprintf(f, "null tree\n"); + } else { + stdump(t, f, nfapresent); + } + fflush(f); +} + +/* + - stdump - recursive guts of dumpst + ^ static void stdump(struct subre *, FILE *, int); + */ +static void +stdump( + struct subre *t, + FILE *f, + int nfapresent) /* is the original NFA still around? */ +{ + char idbuf[50]; + + fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op); + if (t->flags&LONGER) { + fprintf(f, " longest"); + } + if (t->flags&SHORTER) { + fprintf(f, " shortest"); + } + if (t->flags&MIXED) { + fprintf(f, " hasmixed"); + } + if (t->flags&CAP) { + fprintf(f, " hascapture"); + } + if (t->flags&BACKR) { + fprintf(f, " hasbackref"); + } + if (!(t->flags&INUSE)) { + fprintf(f, " UNUSED"); + } + if (t->subno != 0) { + fprintf(f, " (#%d)", t->subno); + } + if (t->min != 1 || t->max != 1) { + fprintf(f, " {%d,", t->min); + if (t->max != DUPINF) { + fprintf(f, "%d", t->max); + } + fprintf(f, "}"); + } + if (nfapresent) { + fprintf(f, " %ld-%ld", (long)t->begin->no, (long)t->end->no); + } + if (t->left != NULL) { + fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf))); + } + if (t->right != NULL) { + fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf))); + } + if (!NULLCNFA(t->cnfa)) { + fprintf(f, "\n"); + dumpcnfa(&t->cnfa, f); + } + fprintf(f, "\n"); + if (t->left != NULL) { + stdump(t->left, f, nfapresent); + } + if (t->right != NULL) { + stdump(t->right, f, nfapresent); + } +} + +/* + - stid - identify a subtree node for dumping + ^ static const char *stid(struct subre *, char *, size_t); + */ +static const char * /* points to buf or constant string */ +stid( + struct subre *t, + char *buf, + size_t bufsize) +{ + /* + * Big enough for hex int or decimal t->id? + */ + + if (bufsize < sizeof(void*)*2 + 3 || bufsize < sizeof(t->id)*3 + 1) { + return "unable"; + } + if (t->id != 0) { + sprintf(buf, "%d", t->id); + } else { + sprintf(buf, "%p", t); + } + return buf; +} + +#include "regc_lex.c" +#include "regc_color.c" +#include "regc_nfa.c" +#include "regc_cvec.c" +#include "regc_locale.c" + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |