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Diffstat (limited to 'src/include/regex/regguts.h')
| -rw-r--r-- | src/include/regex/regguts.h | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/src/include/regex/regguts.h b/src/include/regex/regguts.h new file mode 100644 index 0000000..5d0e7a9 --- /dev/null +++ b/src/include/regex/regguts.h @@ -0,0 +1,482 @@ +/* + * Internal interface definitions, etc., for the reg package + * + * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved. + * + * Development of this software was funded, in part, by Cray Research Inc., + * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics + * Corporation, none of whom are responsible for the results. The author + * thanks all of them. + * + * Redistribution and use in source and binary forms -- with or without + * modification -- are permitted for any purpose, provided that + * redistributions in source form retain this entire copyright notice and + * indicate the origin and nature of any modifications. + * + * I'd appreciate being given credit for this package in the documentation + * of software which uses it, but that is not a requirement. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL + * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * src/include/regex/regguts.h + */ + + + +/* + * Environmental customization. It should not (I hope) be necessary to + * alter the file you are now reading -- regcustom.h should handle it all, + * given care here and elsewhere. + */ +#include "regcustom.h" + + + +/* + * Things that regcustom.h might override. + */ + +/* assertions */ +#ifndef assert +#ifndef REG_DEBUG +#define NDEBUG /* no assertions */ +#endif +#include <assert.h> +#endif + +/* voids */ +#ifndef DISCARD +#define DISCARD void /* for throwing values away */ +#endif +#ifndef VS +#define VS(x) ((void *)(x)) /* cast something to generic ptr */ +#endif + +/* function-pointer declarator */ +#ifndef FUNCPTR +#define FUNCPTR(name, args) (*(name)) args +#endif + +/* memory allocation */ +#ifndef MALLOC +#define MALLOC(n) malloc(n) +#endif +#ifndef REALLOC +#define REALLOC(p, n) realloc(VS(p), n) +#endif +#ifndef FREE +#define FREE(p) free(VS(p)) +#endif + +/* want size of a char in bits, and max value in bounded quantifiers */ +#ifndef _POSIX2_RE_DUP_MAX +#define _POSIX2_RE_DUP_MAX 255 /* normally from <limits.h> */ +#endif + + + +/* + * misc + */ + +#define NOTREACHED 0 + +#define DUPMAX _POSIX2_RE_DUP_MAX +#define DUPINF (DUPMAX+1) + +#define REMAGIC 0xfed7 /* magic number for main struct */ + +/* Type codes for lookaround constraints */ +#define LATYPE_AHEAD_POS 03 /* positive lookahead */ +#define LATYPE_AHEAD_NEG 02 /* negative lookahead */ +#define LATYPE_BEHIND_POS 01 /* positive lookbehind */ +#define LATYPE_BEHIND_NEG 00 /* negative lookbehind */ +#define LATYPE_IS_POS(la) ((la) & 01) +#define LATYPE_IS_AHEAD(la) ((la) & 02) + + +/* + * debugging facilities + */ +#ifdef REG_DEBUG +/* FDEBUG does finite-state tracing */ +#define FDEBUG(arglist) { if (v->eflags®_FTRACE) printf arglist; } +/* MDEBUG does higher-level tracing */ +#define MDEBUG(arglist) { if (v->eflags®_MTRACE) printf arglist; } +#else +#define FDEBUG(arglist) {} +#define MDEBUG(arglist) {} +#endif + + + +/* + * bitmap manipulation + */ +#define UBITS (CHAR_BIT * sizeof(unsigned)) +#define BSET(uv, sn) ((uv)[(sn)/UBITS] |= (unsigned)1 << ((sn)%UBITS)) +#define ISBSET(uv, sn) ((uv)[(sn)/UBITS] & ((unsigned)1 << ((sn)%UBITS))) + + +/* + * As soon as possible, we map chrs into equivalence classes -- "colors" -- + * which are of much more manageable number. + */ +typedef short color; /* colors of characters */ + +#define MAX_COLOR 32767 /* max color (must fit in 'color' datatype) */ +#define COLORLESS (-1) /* impossible color */ +#define WHITE 0 /* default color, parent of all others */ +/* Note: various places in the code know that WHITE is zero */ + + +/* + * Per-color data structure for the compile-time color machinery + * + * If "sub" is not NOSUB then it is the number of the color's current + * subcolor, i.e. we are in process of dividing this color (character + * equivalence class) into two colors. See src/backend/regex/README for + * discussion of subcolors. + * + * Currently-unused colors have the FREECOL bit set and are linked into a + * freelist using their "sub" fields, but only if their color numbers are + * less than colormap.max. Any array entries beyond "max" are just garbage. + */ +struct colordesc +{ + int nschrs; /* number of simple chars of this color */ + int nuchrs; /* number of upper map entries of this color */ + color sub; /* open subcolor, if any; or free-chain ptr */ +#define NOSUB COLORLESS /* value of "sub" when no open subcolor */ + struct arc *arcs; /* chain of all arcs of this color */ + chr firstchr; /* simple char first assigned to this color */ + int flags; /* bit values defined next */ +#define FREECOL 01 /* currently free */ +#define PSEUDO 02 /* pseudocolor, no real chars */ +#define UNUSEDCOLOR(cd) ((cd)->flags & FREECOL) +}; + +/* + * The color map itself + * + * This struct holds both data used only at compile time, and the chr to + * color mapping information, used at both compile and run time. The latter + * is the bulk of the space, so it's not really worth separating out the + * compile-only portion. + * + * Ideally, the mapping data would just be an array of colors indexed by + * chr codes; but for large character sets that's impractical. Fortunately, + * common characters have smaller codes, so we can use a simple array for chr + * codes up to MAX_SIMPLE_CHR, and do something more complex for codes above + * that, without much loss of performance. The "something more complex" is a + * 2-D array of color entries, where row indexes correspond to individual chrs + * or chr ranges that have been mentioned in the regex (with row zero + * representing all other chrs), and column indexes correspond to different + * sets of locale-dependent character classes such as "isalpha". The + * classbits[k] entry is zero if we do not care about the k'th character class + * in this regex, and otherwise it is the bit to be OR'd into the column index + * if the character in question is a member of that class. We find the color + * of a high-valued chr by identifying which colormaprange it is in to get + * the row index (use row zero if it's in none of them), identifying which of + * the interesting cclasses it's in to get the column index, and then indexing + * into the 2-D hicolormap array. + * + * The colormapranges are required to be nonempty, nonoverlapping, and to + * appear in increasing chr-value order. + */ + +#define NUM_CCLASSES 13 /* must match data in regc_locale.c */ + +typedef struct colormaprange +{ + chr cmin; /* range represents cmin..cmax inclusive */ + chr cmax; + int rownum; /* row index in hicolormap array (>= 1) */ +} colormaprange; + +struct colormap +{ + int magic; +#define CMMAGIC 0x876 + struct vars *v; /* for compile error reporting */ + size_t ncds; /* allocated length of colordescs array */ + size_t max; /* highest color number currently in use */ + color free; /* beginning of free chain (if non-0) */ + struct colordesc *cd; /* pointer to array of colordescs */ +#define CDEND(cm) (&(cm)->cd[(cm)->max + 1]) + + /* mapping data for chrs <= MAX_SIMPLE_CHR: */ + color *locolormap; /* simple array indexed by chr code */ + + /* mapping data for chrs > MAX_SIMPLE_CHR: */ + int classbits[NUM_CCLASSES]; /* see comment above */ + int numcmranges; /* number of colormapranges */ + colormaprange *cmranges; /* ranges of high chrs */ + color *hicolormap; /* 2-D array of color entries */ + int maxarrayrows; /* number of array rows allocated */ + int hiarrayrows; /* number of array rows in use */ + int hiarraycols; /* number of array columns (2^N) */ + + /* If we need up to NINLINECDS, we store them here to save a malloc */ +#define NINLINECDS ((size_t) 10) + struct colordesc cdspace[NINLINECDS]; +}; + +/* fetch color for chr; beware of multiple evaluation of c argument */ +#define GETCOLOR(cm, c) \ + ((c) <= MAX_SIMPLE_CHR ? (cm)->locolormap[(c) - CHR_MIN] : pg_reg_getcolor(cm, c)) + + +/* + * Interface definitions for locale-interface functions in regc_locale.c. + */ + +/* + * Representation of a set of characters. chrs[] represents individual + * code points, ranges[] represents ranges in the form min..max inclusive. + * + * If the cvec represents a locale-specific character class, eg [[:alpha:]], + * then the chrs[] and ranges[] arrays contain only members of that class + * up to MAX_SIMPLE_CHR (inclusive). cclasscode is set to regc_locale.c's + * code for the class, rather than being -1 as it is in an ordinary cvec. + * + * Note that in cvecs gotten from newcvec() and intended to be freed by + * freecvec(), both arrays of chrs are after the end of the struct, not + * separately malloc'd; so chrspace and rangespace are effectively immutable. + */ +struct cvec +{ + int nchrs; /* number of chrs */ + int chrspace; /* number of chrs allocated in chrs[] */ + chr *chrs; /* pointer to vector of chrs */ + int nranges; /* number of ranges (chr pairs) */ + int rangespace; /* number of ranges allocated in ranges[] */ + chr *ranges; /* pointer to vector of chr pairs */ + int cclasscode; /* value of "enum classes", or -1 */ +}; + + +/* + * definitions for NFA internal representation + * + * Having a "from" pointer within each arc may seem redundant, but it + * saves a lot of hassle. + */ +struct state; + +struct arc +{ + int type; /* 0 if free, else an NFA arc type code */ + color co; + struct state *from; /* where it's from (and contained within) */ + struct state *to; /* where it's to */ + struct arc *outchain; /* link in *from's outs chain or free chain */ + struct arc *outchainRev; /* back-link in *from's outs chain */ +#define freechain outchain /* we do not maintain "freechainRev" */ + struct arc *inchain; /* link in *to's ins chain */ + struct arc *inchainRev; /* back-link in *to's ins chain */ + struct arc *colorchain; /* link in color's arc chain */ + struct arc *colorchainRev; /* back-link in color's arc chain */ +}; + +struct arcbatch +{ /* for bulk allocation of arcs */ + struct arcbatch *next; +#define ABSIZE 10 + struct arc a[ABSIZE]; +}; + +struct state +{ + int no; +#define FREESTATE (-1) + char flag; /* marks special states */ + int nins; /* number of inarcs */ + struct arc *ins; /* chain of inarcs */ + int nouts; /* number of outarcs */ + struct arc *outs; /* chain of outarcs */ + struct arc *free; /* chain of free arcs */ + struct state *tmp; /* temporary for traversal algorithms */ + struct state *next; /* chain for traversing all */ + struct state *prev; /* back chain */ + struct arcbatch oas; /* first arcbatch, avoid malloc in easy case */ + int noas; /* number of arcs used in first arcbatch */ +}; + +struct nfa +{ + struct state *pre; /* pre-initial state */ + struct state *init; /* initial state */ + struct state *final; /* final state */ + struct state *post; /* post-final state */ + int nstates; /* for numbering states */ + struct state *states; /* state-chain header */ + struct state *slast; /* tail of the chain */ + struct state *free; /* free list */ + struct colormap *cm; /* the color map */ + color bos[2]; /* colors, if any, assigned to BOS and BOL */ + color eos[2]; /* colors, if any, assigned to EOS and EOL */ + struct vars *v; /* simplifies compile error reporting */ + struct nfa *parent; /* parent NFA, if any */ +}; + + + +/* + * definitions for compacted NFA + * + * The main space savings in a compacted NFA is from making the arcs as small + * as possible. We store only the transition color and next-state number for + * each arc. The list of out arcs for each state is an array beginning at + * cnfa.states[statenumber], and terminated by a dummy carc struct with + * co == COLORLESS. + * + * The non-dummy carc structs are of two types: plain arcs and LACON arcs. + * Plain arcs just store the transition color number as "co". LACON arcs + * store the lookaround constraint number plus cnfa.ncolors as "co". LACON + * arcs can be distinguished from plain by testing for co >= cnfa.ncolors. + */ +struct carc +{ + color co; /* COLORLESS is list terminator */ + int to; /* next-state number */ +}; + +struct cnfa +{ + int nstates; /* number of states */ + int ncolors; /* number of colors (max color in use + 1) */ + int flags; +#define HASLACONS 01 /* uses lookaround constraints */ + int pre; /* setup state number */ + int post; /* teardown state number */ + color bos[2]; /* colors, if any, assigned to BOS and BOL */ + color eos[2]; /* colors, if any, assigned to EOS and EOL */ + char *stflags; /* vector of per-state flags bytes */ +#define CNFA_NOPROGRESS 01 /* flag bit for a no-progress state */ + struct carc **states; /* vector of pointers to outarc lists */ + /* states[n] are pointers into a single malloc'd array of arcs */ + struct carc *arcs; /* the area for the lists */ +}; + +#define ZAPCNFA(cnfa) ((cnfa).nstates = 0) +#define NULLCNFA(cnfa) ((cnfa).nstates == 0) + +/* + * This symbol limits the transient heap space used by the regex compiler, + * and thereby also the maximum complexity of NFAs that we'll deal with. + * Currently we only count NFA states and arcs against this; the other + * transient data is generally not large enough to notice compared to those. + * Note that we do not charge anything for the final output data structures + * (the compacted NFA and the colormap). + */ +#ifndef REG_MAX_COMPILE_SPACE +#define REG_MAX_COMPILE_SPACE \ + (100000 * sizeof(struct state) + 100000 * sizeof(struct arcbatch)) +#endif + +/* + * subexpression tree + * + * "op" is one of: + * '=' plain regex without interesting substructure (implemented as DFA) + * 'b' back-reference (has no substructure either) + * '(' capture node: captures the match of its single child + * '.' concatenation: matches a match for left, then a match for right + * '|' alternation: matches a match for left or a match for right + * '*' iteration: matches some number of matches of its single child + * + * Note: the right child of an alternation must be another alternation or + * NULL; hence, an N-way branch requires N alternation nodes, not N-1 as you + * might expect. This could stand to be changed. Actually I'd rather see + * a single alternation node with N children, but that will take revising + * the representation of struct subre. + * + * Note: when a backref is directly quantified, we stick the min/max counts + * into the backref rather than plastering an iteration node on top. This is + * for efficiency: there is no need to search for possible division points. + */ +struct subre +{ + char op; /* see type codes above */ + char flags; +#define LONGER 01 /* prefers longer match */ +#define SHORTER 02 /* prefers shorter match */ +#define MIXED 04 /* mixed preference below */ +#define CAP 010 /* capturing parens below */ +#define BACKR 020 /* back reference below */ +#define INUSE 0100 /* in use in final tree */ +#define NOPROP 03 /* bits which may not propagate up */ +#define LMIX(f) ((f)<<2) /* LONGER -> MIXED */ +#define SMIX(f) ((f)<<1) /* SHORTER -> MIXED */ +#define UP(f) (((f)&~NOPROP) | (LMIX(f) & SMIX(f) & MIXED)) +#define MESSY(f) ((f)&(MIXED|CAP|BACKR)) +#define PREF(f) ((f)&NOPROP) +#define PREF2(f1, f2) ((PREF(f1) != 0) ? PREF(f1) : PREF(f2)) +#define COMBINE(f1, f2) (UP((f1)|(f2)) | PREF2(f1, f2)) + short id; /* ID of subre (1..ntree-1) */ + int subno; /* subexpression number for 'b' and '(', or + * LATYPE code for lookaround constraint */ + short min; /* min repetitions for iteration or backref */ + short max; /* max repetitions for iteration or backref */ + struct subre *left; /* left child, if any (also freelist chain) */ + struct subre *right; /* right child, if any */ + struct state *begin; /* outarcs from here... */ + struct state *end; /* ...ending in inarcs here */ + struct cnfa cnfa; /* compacted NFA, if any */ + struct subre *chain; /* for bookkeeping and error cleanup */ +}; + + + +/* + * table of function pointers for generic manipulation functions + * A regex_t's re_fns points to one of these. + */ +struct fns +{ + void FUNCPTR(free, (regex_t *)); + int FUNCPTR(cancel_requested, (void)); + int FUNCPTR(stack_too_deep, (void)); +}; + +#define CANCEL_REQUESTED(re) \ + ((*((struct fns *) (re)->re_fns)->cancel_requested) ()) + +#define STACK_TOO_DEEP(re) \ + ((*((struct fns *) (re)->re_fns)->stack_too_deep) ()) + + +/* + * the insides of a regex_t, hidden behind a void * + */ +struct guts +{ + int magic; +#define GUTSMAGIC 0xfed9 + int cflags; /* copy of compile flags */ + long info; /* copy of re_info */ + size_t nsub; /* copy of re_nsub */ + struct subre *tree; + struct cnfa search; /* for fast preliminary search */ + int ntree; /* number of subre's, plus one */ + struct colormap cmap; + int FUNCPTR(compare, (const chr *, const chr *, size_t)); + struct subre *lacons; /* lookaround-constraint vector */ + int nlacons; /* size of lacons[]; note that only slots + * numbered 1 .. nlacons-1 are used */ +}; + + +/* prototypes for functions that are exported from regcomp.c to regexec.c */ +extern void pg_set_regex_collation(Oid collation); +extern color pg_reg_getcolor(struct colormap *cm, chr c); |