454 lines
15 KiB
C
454 lines
15 KiB
C
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/*
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* Internal interface definitions, etc., for the reg package
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*
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* Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
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*
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* Development of this software was funded, in part, by Cray Research Inc.,
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* UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
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* Corporation, none of whom are responsible for the results. The author
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* thanks all of them.
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*
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* Redistribution and use in source and binary forms -- with or without
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* modification -- are permitted for any purpose, provided that
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* redistributions in source form retain this entire copyright notice and
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* indicate the origin and nature of any modifications.
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*
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* I'd appreciate being given credit for this package in the documentation of
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* software which uses it, but that is not a requirement.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Environmental customization. It should not (I hope) be necessary to alter
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* the file you are now reading -- regcustom.h should handle it all, given
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* care here and elsewhere.
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*/
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#include "regcustom.h"
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/*
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* Things that regcustom.h might override.
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*/
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/* assertions */
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#ifndef assert
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#ifndef REG_DEBUG
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#ifndef NDEBUG
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#define NDEBUG /* no assertions */
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#endif
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#endif /* !REG_DEBUG */
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#include <assert.h>
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#endif
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/* voids */
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#ifndef VOID
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#define VOID void /* for function return values */
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#endif
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#ifndef DISCARD
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#define DISCARD void /* for throwing values away */
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#endif
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#ifndef PVOID
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#define PVOID void * /* generic pointer */
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#endif
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#ifndef VS
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#define VS(x) ((void*)(x)) /* cast something to generic ptr */
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#endif
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#ifndef NOPARMS
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#define NOPARMS void /* for empty parm lists */
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#endif
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/* function-pointer declarator */
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#ifndef FUNCPTR
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#if __STDC__ >= 1
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#define FUNCPTR(name, args) (*name)args
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#else
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#define FUNCPTR(name, args) (*name)()
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#endif
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#endif
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/* memory allocation */
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#ifndef MALLOC
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#define MALLOC(n) malloc(n)
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#endif
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#ifndef REALLOC
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#define REALLOC(p, n) realloc(VS(p), n)
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#endif
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#ifndef FREE
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#define FREE(p) free(VS(p))
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#endif
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/* want size of a char in bits, and max value in bounded quantifiers */
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#ifndef _POSIX2_RE_DUP_MAX
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#define _POSIX2_RE_DUP_MAX 255 /* normally from <limits.h> */
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#endif
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/*
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* misc
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*/
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#define NOTREACHED 0
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#define xxx 1
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#define DUPMAX _POSIX2_RE_DUP_MAX
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#define DUPINF (DUPMAX+1)
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#define REMAGIC 0xFED7 /* magic number for main struct */
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/*
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* debugging facilities
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*/
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#ifdef REG_DEBUG
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/* FDEBUG does finite-state tracing */
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#define FDEBUG(arglist) { if (v->eflags®_FTRACE) printf arglist; }
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/* MDEBUG does higher-level tracing */
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#define MDEBUG(arglist) { if (v->eflags®_MTRACE) printf arglist; }
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#else
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#define FDEBUG(arglist) {}
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#define MDEBUG(arglist) {}
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#endif
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/*
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* bitmap manipulation
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*/
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#define UBITS (CHAR_BIT * sizeof(unsigned))
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#define BSET(uv, sn) ((uv)[(sn)/UBITS] |= (unsigned)1 << ((sn)%UBITS))
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#define ISBSET(uv, sn) ((uv)[(sn)/UBITS] & ((unsigned)1 << ((sn)%UBITS)))
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/*
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* We dissect a chr into byts for colormap table indexing. Here we define a
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* byt, which will be the same as a byte on most machines... The exact size of
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* a byt is not critical, but about 8 bits is good, and extraction of 8-bit
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* chunks is sometimes especially fast.
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*/
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#ifndef BYTBITS
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#define BYTBITS 8 /* bits in a byt */
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#endif
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#define BYTTAB (1<<BYTBITS) /* size of table with one entry per byt value */
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#define BYTMASK (BYTTAB-1) /* bit mask for byt */
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#define NBYTS ((CHRBITS+BYTBITS-1)/BYTBITS)
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/* the definition of GETCOLOR(), below, assumes NBYTS <= 4 */
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/*
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* As soon as possible, we map chrs into equivalence classes -- "colors" --
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* which are of much more manageable number.
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*/
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typedef short color; /* colors of characters */
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typedef int pcolor; /* what color promotes to */
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#define MAX_COLOR SHRT_MAX /* max color value */
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#define COLORLESS (-1) /* impossible color */
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#define WHITE 0 /* default color, parent of all others */
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/*
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* A colormap is a tree -- more precisely, a DAG -- indexed at each level by a
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* byt of the chr, to map the chr to a color efficiently. Because lower
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* sections of the tree can be shared, it can exploit the usual sparseness of
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* such a mapping table. The tree is always NBYTS levels deep (in the past it
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* was shallower during construction but was "filled" to full depth at the end
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* of that); areas that are unaltered as yet point to "fill blocks" which are
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* entirely WHITE in color.
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*/
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/* the tree itself */
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struct colors {
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color ccolor[BYTTAB];
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};
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struct ptrs {
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union tree *pptr[BYTTAB];
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};
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union tree {
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struct colors colors;
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struct ptrs ptrs;
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};
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#define tcolor colors.ccolor
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#define tptr ptrs.pptr
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/* Internal per-color descriptor structure for the color machinery */
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struct colordesc {
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uchr nchrs; /* number of chars of this color */
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color sub; /* open subcolor (if any); free chain ptr */
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#define NOSUB COLORLESS
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struct arc *arcs; /* color chain */
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int flags;
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#define FREECOL 01 /* currently free */
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#define PSEUDO 02 /* pseudocolor, no real chars */
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#define UNUSEDCOLOR(cd) ((cd)->flags&FREECOL)
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union tree *block; /* block of solid color, if any */
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};
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/*
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* The color map itself
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*
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* Much of the data in the colormap struct is only used at compile time.
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* However, the bulk of the space usage is in the "tree" structure, so it's
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* not clear that there's much point in converting the rest to a more compact
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* form when compilation is finished.
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*/
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struct colormap {
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int magic;
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#define CMMAGIC 0x876
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struct vars *v; /* for compile error reporting */
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size_t ncds; /* number of colordescs */
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size_t max; /* highest in use */
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color free; /* beginning of free chain (if non-0) */
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struct colordesc *cd;
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#define CDEND(cm) (&(cm)->cd[(cm)->max + 1])
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#define NINLINECDS ((size_t)10)
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struct colordesc cdspace[NINLINECDS];
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union tree tree[NBYTS]; /* tree top, plus fill blocks */
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};
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/* optimization magic to do fast chr->color mapping */
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#define B0(c) ((c) & BYTMASK)
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#define B1(c) (((c)>>BYTBITS) & BYTMASK)
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#define B2(c) (((c)>>(2*BYTBITS)) & BYTMASK)
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#define B3(c) (((c)>>(3*BYTBITS)) & BYTMASK)
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#if NBYTS == 1
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#define GETCOLOR(cm, c) ((cm)->tree->tcolor[B0(c)])
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#endif
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/* beware, for NBYTS>1, GETCOLOR() is unsafe -- 2nd arg used repeatedly */
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#if NBYTS == 2
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#define GETCOLOR(cm, c) ((cm)->tree->tptr[B1(c)]->tcolor[B0(c)])
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#endif
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#if NBYTS == 4
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#define GETCOLOR(cm, c) ((cm)->tree->tptr[B3(c)]->tptr[B2(c)]->tptr[B1(c)]->tcolor[B0(c)])
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#endif
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/*
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* Interface definitions for locale-interface functions in locale.c.
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*/
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/* Representation of a set of characters. */
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struct cvec {
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int nchrs; /* number of chrs */
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int chrspace; /* number of chrs possible */
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chr *chrs; /* pointer to vector of chrs */
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int nranges; /* number of ranges (chr pairs) */
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int rangespace; /* number of chrs possible */
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chr *ranges; /* pointer to vector of chr pairs */
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};
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/*
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* definitions for non-deterministic finite autmaton (NFA) internal
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* representation
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*
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* Having a "from" pointer within each arc may seem redundant, but it saves a
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* lot of hassle.
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*/
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struct state;
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struct arc {
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int type; /* 0 if free, else an NFA arc type code */
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color co;
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struct state *from; /* where it's from (and contained within) */
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struct state *to; /* where it's to */
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struct arc *outchain; /* link in *from's outs chain or free chain */
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struct arc *outchainRev; /* back-link in *from's outs chain */
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#define freechain outchain /* we do not maintain "freechainRev" */
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struct arc *inchain; /* *to's ins chain */
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struct arc *inchainRev; /* back-link in *to's ins chain */
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struct arc *colorchain; /* color's arc chain */
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struct arc *colorchainRev; /* back-link in color's arc chain */
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};
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struct arcbatch { /* for bulk allocation of arcs */
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struct arcbatch *next;
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#define ABSIZE 10
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struct arc a[ABSIZE];
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};
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struct state {
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int no;
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#define FREESTATE (-1)
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char flag; /* marks special states */
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int nins; /* number of inarcs */
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struct arc *ins; /* chain of inarcs */
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int nouts; /* number of outarcs */
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struct arc *outs; /* chain of outarcs */
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struct arc *free; /* chain of free arcs */
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struct state *tmp; /* temporary for traversal algorithms */
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struct state *next; /* chain for traversing all */
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struct state *prev; /* back chain */
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struct arcbatch oas; /* first arcbatch, avoid malloc in easy case */
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int noas; /* number of arcs used in first arcbatch */
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};
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struct nfa {
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struct state *pre; /* pre-initial state */
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struct state *init; /* initial state */
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struct state *final; /* final state */
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struct state *post; /* post-final state */
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int nstates; /* for numbering states */
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struct state *states; /* state-chain header */
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struct state *slast; /* tail of the chain */
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struct state *free; /* free list */
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struct colormap *cm; /* the color map */
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color bos[2]; /* colors, if any, assigned to BOS and BOL */
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color eos[2]; /* colors, if any, assigned to EOS and EOL */
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struct vars *v; /* simplifies compile error reporting */
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struct nfa *parent; /* parent NFA, if any */
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};
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/*
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* definitions for compacted NFA
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*
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* The main space savings in a compacted NFA is from making the arcs as small
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* as possible. We store only the transition color and next-state number for
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* each arc. The list of out arcs for each state is an array beginning at
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* cnfa.states[statenumber], and terminated by a dummy carc struct with
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* co == COLORLESS.
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*
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* The non-dummy carc structs are of two types: plain arcs and LACON arcs.
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* Plain arcs just store the transition color number as "co". LACON arcs
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* store the lookahead constraint number plus cnfa.ncolors as "co". LACON
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* arcs can be distinguished from plain by testing for co >= cnfa.ncolors.
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*/
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struct carc {
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color co; /* COLORLESS is list terminator */
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int to; /* next-state number */
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};
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struct cnfa {
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int nstates; /* number of states */
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int ncolors; /* number of colors */
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int flags;
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#define HASLACONS 01 /* uses lookahead constraints */
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int pre; /* setup state number */
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int post; /* teardown state number */
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color bos[2]; /* colors, if any, assigned to BOS and BOL */
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color eos[2]; /* colors, if any, assigned to EOS and EOL */
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char *stflags; /* vector of per-state flags bytes */
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#define CNFA_NOPROGRESS 01 /* flag bit for a no-progress state */
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struct carc **states; /* vector of pointers to outarc lists */
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/* states[n] are pointers into a single malloc'd array of arcs */
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struct carc *arcs; /* the area for the lists */
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};
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#define ZAPCNFA(cnfa) ((cnfa).nstates = 0)
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#define NULLCNFA(cnfa) ((cnfa).nstates == 0)
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/*
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* This symbol limits the transient heap space used by the regex compiler,
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* and thereby also the maximum complexity of NFAs that we'll deal with.
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* Currently we only count NFA states and arcs against this; the other
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* transient data is generally not large enough to notice compared to those.
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* Note that we do not charge anything for the final output data structures
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* (the compacted NFA and the colormap).
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*/
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#ifndef REG_MAX_COMPILE_SPACE
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#define REG_MAX_COMPILE_SPACE \
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(100000 * sizeof(struct state) + 100000 * sizeof(struct arcbatch))
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#endif
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/*
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* subexpression tree
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*
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* "op" is one of:
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* '=' plain regex without interesting substructure (implemented as DFA)
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* 'b' back-reference (has no substructure either)
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* '(' capture node: captures the match of its single child
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* '.' concatenation: matches a match for left, then a match for right
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* '|' alternation: matches a match for left or a match for right
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* '*' iteration: matches some number of matches of its single child
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*
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* Note: the right child of an alternation must be another alternation or
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* NULL; hence, an N-way branch requires N alternation nodes, not N-1 as you
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* might expect. This could stand to be changed. Actually I'd rather see
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* a single alternation node with N children, but that will take revising
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* the representation of struct subre.
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*
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* Note: when a backref is directly quantified, we stick the min/max counts
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* into the backref rather than plastering an iteration node on top. This is
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* for efficiency: there is no need to search for possible division points.
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*/
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struct subre {
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char op; /* see type codes above */
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char flags;
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#define LONGER 01 /* prefers longer match */
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#define SHORTER 02 /* prefers shorter match */
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#define MIXED 04 /* mixed preference below */
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#define CAP 010 /* capturing parens below */
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#define BACKR 020 /* back reference below */
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#define INUSE 0100 /* in use in final tree */
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#define NOPROP 03 /* bits which may not propagate up */
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#define LMIX(f) ((f)<<2) /* LONGER -> MIXED */
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#define SMIX(f) ((f)<<1) /* SHORTER -> MIXED */
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#define UP(f) (((f)&~NOPROP) | (LMIX(f) & SMIX(f) & MIXED))
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#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 '(') */
|
|||
|
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 *));
|
|||
|
};
|
|||
|
|
|||
|
/*
|
|||
|
* 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 */
|
|||
|
};
|
|||
|
|
|||
|
/*
|
|||
|
* Magic for allocating a variable workspace. This default version is
|
|||
|
* stack-hungry.
|
|||
|
*/
|
|||
|
|
|||
|
#ifndef AllocVars
|
|||
|
#define AllocVars(vPtr) \
|
|||
|
struct vars var; \
|
|||
|
struct vars *vPtr = &var
|
|||
|
#endif
|
|||
|
#ifndef FreeVars
|
|||
|
#define FreeVars(vPtr) ((void) 0)
|
|||
|
#endif
|
|||
|
|
|||
|
/*
|
|||
|
* Local Variables:
|
|||
|
* mode: c
|
|||
|
* c-basic-offset: 4
|
|||
|
* fill-column: 78
|
|||
|
* End:
|
|||
|
*/
|