/* * 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 #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 */ #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))) /* * known character classes */ enum char_classes { CC_ALNUM, CC_ALPHA, CC_ASCII, CC_BLANK, CC_CNTRL, CC_DIGIT, CC_GRAPH, CC_LOWER, CC_PRINT, CC_PUNCT, CC_SPACE, CC_UPPER, CC_XDIGIT, CC_WORD }; #define NUM_CCLASSES 14 /* * As soon as possible, we map chrs into equivalence classes -- "colors" -- * which are of much more manageable number. * * To further reduce the number of arcs in NFAs and DFAs, we also have a * special RAINBOW "color" that can be assigned to an arc. This is not a * real color, in that it has no entry in color maps. */ typedef short color; /* colors of characters */ #define MAX_COLOR 32767 /* max color (must fit in 'color' datatype) */ #define COLORLESS (-1) /* impossible color */ #define RAINBOW (-2) /* represents all colors except pseudocolors */ #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; /* bitmask of the following flags: */ #define FREECOL 01 /* currently free */ #define PSEUDO 02 /* pseudocolor, no real chars */ #define COLMARK 04 /* temporary marker used in some functions */ }; #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. */ 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 */ struct state; struct arc { int type; /* 0 if free, else an NFA arc type code */ color co; /* color the arc matches (possibly RAINBOW) */ struct state *from; /* where it's from */ 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 */ /* these fields are not used when co == RAINBOW: */ 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; /* chain link */ size_t narcs; /* number of arcs allocated in this arcbatch */ struct arc a[FLEXIBLE_ARRAY_MEMBER]; }; #define ARCBATCHSIZE(n) ((n) * sizeof(struct arc) + offsetof(struct arcbatch, a)) /* first batch will have FIRSTABSIZE arcs; then double it until MAXABSIZE */ #define FIRSTABSIZE 64 #define MAXABSIZE 1024 struct state { int no; /* state number, zero and up; or FREESTATE */ #define FREESTATE (-1) char flag; /* marks special states */ int nins; /* number of inarcs */ int nouts; /* number of outarcs */ struct arc *ins; /* chain of inarcs */ struct arc *outs; /* chain of outarcs */ struct state *tmp; /* temporary for traversal algorithms */ struct state *next; /* chain for traversing all live states */ /* the "next" field is also used to chain free states together */ struct state *prev; /* back-link in chain of all live states */ }; struct statebatch { /* for bulk allocation of states */ struct statebatch *next; /* chain link */ size_t nstates; /* number of states allocated in this batch */ struct state s[FLEXIBLE_ARRAY_MEMBER]; }; #define STATEBATCHSIZE(n) ((n) * sizeof(struct state) + offsetof(struct statebatch, s)) /* first batch will have FIRSTSBSIZE states; then double it until MAXSBSIZE */ #define FIRSTSBSIZE 32 #define MAXSBSIZE 1024 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; /* chain of live states */ struct state *slast; /* tail of the chain */ struct state *freestates; /* chain of free states */ struct arc *freearcs; /* chain of free arcs */ struct statebatch *lastsb; /* chain of statebatches */ struct arcbatch *lastab; /* chain of arcbatches */ size_t lastsbused; /* number of states consumed from *lastsb */ size_t lastabused; /* number of arcs consumed from *lastab */ 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 */ int flags; /* flags to pass forward to cNFA */ int minmatchall; /* min number of chrs to match, if matchall */ int maxmatchall; /* max number of chrs to match, or DUPINF */ 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. * * Note that in a plain arc, "co" can be RAINBOW; since that's negative, * it doesn't break the rule about how to recognize LACON arcs. * * We have special markings for "trivial" NFAs that can match any string * (possibly with limits on the number of characters therein). In such a * case, flags & MATCHALL is set (and HASLACONS can't be set). Then the * fields minmatchall and maxmatchall give the minimum and maximum numbers * of characters to match. For example, ".*" produces minmatchall = 0 * and maxmatchall = DUPINF, while ".+" produces minmatchall = 1 and * maxmatchall = DUPINF. */ 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; /* bitmask of the following flags: */ #define HASLACONS 01 /* uses lookaround constraints */ #define MATCHALL 02 /* matches all strings of a range of lengths */ 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 */ /* these fields are used only in a MATCHALL NFA (else they're -1): */ int minmatchall; /* min number of chrs to match */ int maxmatchall; /* max number of chrs to match, or DUPINF */ }; /* * When debugging, it's helpful if an un-filled CNFA is all-zeroes. * In production, though, we only require nstates to be zero. */ #ifdef REG_DEBUG #define ZAPCNFA(cnfa) memset(&(cnfa), 0, sizeof(cnfa)) #else #define ZAPCNFA(cnfa) ((cnfa).nstates = 0) #endif #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). * The scaling here is based on an empirical measurement that very large * NFAs tend to have about 4 arcs/state. */ #ifndef REG_MAX_COMPILE_SPACE #define REG_MAX_COMPILE_SPACE \ (500000 * (sizeof(struct state) + 4 * sizeof(struct arc))) #endif /* * subexpression tree * * "op" is one of: * '=' plain regex without interesting substructure (implemented as DFA) * 'b' back-reference (has no substructure either) * '(' no-op capture node: captures the match of its single child * '.' concatenation: matches a match for first child, then second child * '|' alternation: matches a match for any of its children * '*' iteration: matches some number of matches of its single child * * An alternation node can have any number of children (but at least two), * linked through their sibling fields. * * A concatenation node must have exactly two children. It might be useful * to support more, but that would complicate the executor. Note that it is * the first child's greediness that determines the node's preference for * where to split a match. * * 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 here or below */ #define BACKR 020 /* back reference here or below */ #define BRUSE 040 /* is referenced by a back reference */ #define INUSE 0100 /* in use in final tree */ #define UPPROP (MIXED|CAP|BACKR) /* flags which should propagate up */ #define LMIX(f) ((f)<<2) /* LONGER -> MIXED */ #define SMIX(f) ((f)<<1) /* SHORTER -> MIXED */ #define UP(f) (((f)&UPPROP) | (LMIX(f) & SMIX(f) & MIXED)) #define MESSY(f) ((f)&(MIXED|CAP|BACKR)) #define PREF(f) ((f)&(LONGER|SHORTER)) #define PREF2(f1, f2) ((PREF(f1) != 0) ? PREF(f1) : PREF(f2)) #define COMBINE(f1, f2) (UP((f1)|(f2)) | PREF2(f1, f2)) char latype; /* LATYPE code, if lookaround constraint */ int id; /* ID of subre (1..ntree-1) */ int capno; /* if capture node, subno to capture into */ int backno; /* if backref node, subno it refers to */ short min; /* min repetitions for iteration or backref */ short max; /* max repetitions for iteration or backref */ struct subre *child; /* first child, if any (also freelist chain) */ struct subre *sibling; /* next child of same parent, 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);