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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/regex/regguts.h
parentInitial commit. (diff)
downloadpostgresql-14-46651ce6fe013220ed397add242004d764fc0153.tar.xz
postgresql-14-46651ce6fe013220ed397add242004d764fc0153.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/regex/regguts.h')
-rw-r--r--src/include/regex/regguts.h546
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diff --git a/src/include/regex/regguts.h b/src/include/regex/regguts.h
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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&REG_FTRACE) printf arglist; }
+/* MDEBUG does higher-level tracing */
+#define MDEBUG(arglist) { if (v->eflags&REG_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 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))
+ 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);