diff options
Diffstat (limited to 'generic/regguts.h')
| -rw-r--r-- | generic/regguts.h | 170 |
1 files changed, 94 insertions, 76 deletions
diff --git a/generic/regguts.h b/generic/regguts.h index 190d40b..ad9d5b9 100644 --- a/generic/regguts.h +++ b/generic/regguts.h @@ -39,15 +39,6 @@ * Things that regcustom.h might override. */ -/* standard header files (NULL is a reasonable indicator for them) */ -#ifndef NULL -#include <stdio.h> -#include <stdlib.h> -#include <ctype.h> -#include <limits.h> -#include <string.h> -#endif - /* assertions */ #ifndef assert #ifndef REG_DEBUG @@ -58,54 +49,20 @@ #include <assert.h> #endif -/* voids */ -#ifndef VOID -#define VOID void /* for function return values */ -#endif -#ifndef DISCARD -#define DISCARD void /* for throwing values away */ -#endif -#ifndef PVOID -#define PVOID void * /* generic pointer */ -#endif -#ifndef VS -#define VS(x) ((void*)(x)) /* cast something to generic ptr */ -#endif -#ifndef NOPARMS -#define NOPARMS void /* for empty parm lists */ -#endif - -/* const */ -#ifndef CONST -#define CONST const /* for old compilers, might be empty */ -#endif - -/* function-pointer declarator */ -#ifndef FUNCPTR -#if __STDC__ >= 1 -#define FUNCPTR(name, args) (*name)args -#else -#define FUNCPTR(name, args) (*name)() -#endif -#endif - /* memory allocation */ #ifndef MALLOC #define MALLOC(n) malloc(n) #endif #ifndef REALLOC -#define REALLOC(p, n) realloc(VS(p), n) +#define REALLOC(p, n) realloc(p, n) #endif #ifndef FREE -#define FREE(p) free(VS(p)) +#define FREE(p) free(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> */ +#define _POSIX2_RE_DUP_MAX 255 /* normally from <limits.h> */ #endif /* @@ -116,7 +73,7 @@ #define xxx 1 #define DUPMAX _POSIX2_RE_DUP_MAX -#define INFINITY (DUPMAX+1) +#define DUPINF (DUPMAX+1) #define REMAGIC 0xfed7 /* magic number for main struct */ @@ -162,6 +119,7 @@ typedef short color; /* colors of characters */ typedef int pcolor; /* what color promotes to */ +#define MAX_COLOR SHRT_MAX /* max color value */ #define COLORLESS (-1) /* impossible color */ #define WHITE 0 /* default color, parent of all others */ @@ -189,7 +147,7 @@ union tree { #define tcolor colors.ccolor #define tptr ptrs.pptr -/* internal per-color structure for the color machinery */ +/* Internal per-color descriptor structure for the color machinery */ struct colordesc { uchr nchrs; /* number of chars of this color */ color sub; /* open subcolor (if any); free chain ptr */ @@ -202,7 +160,14 @@ struct colordesc { union tree *block; /* block of solid color, if any */ }; -/* the color map itself */ +/* + * 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 @@ -235,9 +200,9 @@ struct colormap { /* * Interface definitions for locale-interface functions in locale.c. - * Multi-character collating elements (MCCEs) cause most of the trouble. */ +/* Representation of a set of characters. */ struct cvec { int nchrs; /* number of chrs */ int chrspace; /* number of chrs possible */ @@ -245,18 +210,11 @@ struct cvec { int nranges; /* number of ranges (chr pairs) */ int rangespace; /* number of chrs possible */ chr *ranges; /* pointer to vector of chr pairs */ - int nmcces; /* number of MCCEs */ - int mccespace; /* number of MCCEs possible */ - int nmccechrs; /* number of chrs used for MCCEs */ - chr *mcces[1]; /* pointers to 0-terminated MCCEs */ - /* and both batches of chrs are on the end */ }; -/* caution: this value cannot be changed easily */ -#define MAXMCCE 2 /* length of longest MCCE */ - /* - * definitions for NFA internal representation + * definitions for non-deterministic finite autmaton (NFA) internal + * representation * * Having a "from" pointer within each arc may seem redundant, but it saves a * lot of hassle. @@ -265,15 +223,17 @@ struct cvec { struct state; struct arc { - int type; -#define ARCFREE '\0' + 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; /* *from's outs chain or free chain */ -#define freechain outchain + 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; /* *to's ins chain */ + struct arc *inchainRev; /* back-link in *to's ins chain */ struct arc *colorchain; /* color's arc chain */ + struct arc *colorchainRev; /* back-link in color's arc chain */ }; struct arcbatch { /* for bulk allocation of arcs */ @@ -284,7 +244,7 @@ struct arcbatch { /* for bulk allocation of arcs */ struct state { int no; -# define FREESTATE (-1) +#define FREESTATE (-1) char flag; /* marks special states */ int nins; /* number of inarcs */ struct arc *ins; /* chain of inarcs */ @@ -316,11 +276,22 @@ struct nfa { /* * 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; /* state number */ + int to; /* next-state number */ }; struct cnfa { @@ -332,19 +303,52 @@ struct cnfa { 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; /* '|', '.' (concat), 'b' (backref), '(', - * '=' */ + char op; /* see type codes above */ char flags; #define LONGER 01 /* prefers longer match */ #define SHORTER 02 /* prefers shorter match */ @@ -352,18 +356,18 @@ struct subre { #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 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)&~LOCAL) | (LMIX(f) & SMIX(f) & MIXED)) +#define UP(f) (((f)&~NOPROP) | (LMIX(f) & SMIX(f) & MIXED)) #define MESSY(f) ((f)&(MIXED|CAP|BACKR)) -#define PREF(f) ((f)&LOCAL) +#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 retry; /* index into retry memory */ + short id; /* ID of subre (1..ntree-1) */ int subno; /* subexpression number (for 'b' and '(') */ - short min; /* min repetitions, for backref only */ - short max; /* max repetitions, for backref only */ + 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... */ @@ -378,7 +382,7 @@ struct subre { */ struct fns { - VOID FUNCPTR(free, (regex_t *)); + void (*free) (regex_t *); }; /* @@ -393,12 +397,26 @@ struct guts { size_t nsub; /* copy of re_nsub */ struct subre *tree; struct cnfa search; /* for fast preliminary search */ - int ntree; + int ntree; /* number of subre's, plus one */ struct colormap cmap; - int FUNCPTR(compare, (CONST chr *, CONST chr *, size_t)); + int (*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; \ + register struct vars *vPtr = &var +#endif +#ifndef FreeVars +#define FreeVars(vPtr) ((void) 0) +#endif /* * Local Variables: |