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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 _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)))
/*
* 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.
*
* Leaf-level tree blocks are of type "struct colors", while upper-level
* blocks are of type "struct ptrs". Pointers into the tree are generally
* declared as "union tree *" to be agnostic about what level they point to.
*/
/* the tree itself */
struct colors
{
color ccolor[BYTTAB];
};
struct ptrs
{
union tree *pptr[BYTTAB];
};
union tree
{
struct colors colors;
struct ptrs ptrs;
};
/* use these pseudo-field names when dereferencing a "union tree" pointer */
#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 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 */
};
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