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/* * 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 CHAR_BIT #include <limits.h> #endif #ifndef _POSIX2_RE_DUP_MAX #define _POSIX2_RE_DUP_MAX 255 /* normally from <limits.h> */ #endif /* * misc */ #define NOTREACHED 0 #define xxx 1 #define DUPMAX _POSIX2_RE_DUP_MAX #define INFINITY (DUPMAX+1) #define REMAGIC 0xfed7 /* magic number for main struct */ /* * 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))) /* * We dissect a chr into byts for colormap table indexing. Here we define * a byt, which will be the same as a byte on most machines... The exact * size of a byt is not critical, but about 8 bits is good, and extraction * of 8-bit chunks is sometimes especially fast. */ #ifndef BYTBITS #define BYTBITS 8 /* bits in a byt */ #endif #define BYTTAB (1<<BYTBITS) /* size of table with one entry per byt value */ #define BYTMASK (BYTTAB-1) /* bit mask for byt */ #define NBYTS ((CHRBITS+BYTBITS-1)/BYTBITS) /* the definition of GETCOLOR(), below, assumes NBYTS <= 4 */ /* * As soon as possible, we map chrs into equivalence classes -- "colors" -- * which are of much more manageable number. */ typedef short color; /* colors of characters */ typedef int pcolor; /* what color promotes to */ #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 */ /* * A colormap is a tree -- more precisely, a DAG -- indexed at each level * by a byt of the chr, to map the chr to a color efficiently. Because * lower sections of the tree can be shared, it can exploit the usual * sparseness of such a mapping table. The tree is always NBYTS levels * deep (in the past it was shallower during construction but was "filled" * to full depth at the end of that); areas that are unaltered as yet point * to "fill blocks" which are entirely WHITE in color. */ /* the tree itself */ struct colors { color ccolor[BYTTAB]; }; struct ptrs { union tree *pptr[BYTTAB]; }; union tree { struct colors colors; struct ptrs ptrs; }; #define tcolor colors.ccolor #define tptr ptrs.pptr /* * 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 { uchr nchrs; /* number of chars 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; /* 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) union tree *block; /* block of solid color, if any */ }; /* * The color map itself * * Much of the data in the colormap struct is only used at compile time. * However, the bulk of the space usage is in the "tree" structure, so it's * not clear that there's much point in converting the rest to a more compact * form when compilation is finished. */ 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]) /* If we need up to NINLINECDS, we store them here to save a malloc */ #define NINLINECDS ((size_t)10) struct colordesc cdspace[NINLINECDS]; union tree tree[NBYTS]; /* tree top, plus lower-level fill blocks */ }; /* optimization magic to do fast chr->color mapping */ #define B0(c) ((c) & BYTMASK) #define B1(c) (((c)>>BYTBITS) & BYTMASK) #define B2(c) (((c)>>(2*BYTBITS)) & BYTMASK) #define B3(c) (((c)>>(3*BYTBITS)) & BYTMASK) #if NBYTS == 1 #define GETCOLOR(cm, c) ((cm)->tree->tcolor[B0(c)]) #endif /* beware, for NBYTS>1, GETCOLOR() is unsafe -- 2nd arg used repeatedly */ #if NBYTS == 2 #define GETCOLOR(cm, c) ((cm)->tree->tptr[B1(c)]->tcolor[B0(c)]) #endif #if NBYTS == 4 #define GETCOLOR(cm, c) ((cm)->tree->tptr[B3(c)]->tptr[B2(c)]->tptr[B1(c)]->tcolor[B0(c)]) #endif /* * 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. * * 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 */ }; /* * 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 lookahead 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 lookahead 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 LOCAL 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)&~LOCAL) | (LMIX(f) & SMIX(f) & MIXED)) #define MESSY(f) ((f)&(MIXED|CAP|BACKR)) #define PREF(f) ((f)&LOCAL) #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 '(') */ 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; /* lookahead-constraint vector */ int nlacons; /* size of lacons */ };