Initial import of Perl5. The king is dead; long live the king!

1 files changed, 2672 insertions, 0 deletions

diff --git a/contrib/perl5/regcomp.c b/contrib/perl5/regcomp.c
new file mode 100644
index 0000000..f2f51a4
--- /dev/null
+++ b/contrib/perl5/regcomp.c
@@ -0,0 +1,2672 @@
+/*    regcomp.c
+ */
+
+/*
+ * "A fair jaw-cracker dwarf-language must be."  --Samwise Gamgee
+ */
+
+/* NOTE: this is derived from Henry Spencer's regexp code, and should not
+ * confused with the original package (see point 3 below).  Thanks, Henry!
+ */
+
+/* Additional note: this code is very heavily munged from Henry's version
+ * in places.  In some spots I've traded clarity for efficiency, so don't
+ * blame Henry for some of the lack of readability.
+ */
+
+/* The names of the functions have been changed from regcomp and
+ * regexec to  pregcomp and pregexec in order to avoid conflicts
+ * with the POSIX routines of the same names.
+*/
+
+#ifdef PERL_EXT_RE_BUILD
+/* need to replace pregcomp et al, so enable that */
+#  ifndef PERL_IN_XSUB_RE
+#    define PERL_IN_XSUB_RE
+#  endif
+/* need access to debugger hooks */
+#  ifndef DEBUGGING
+#    define DEBUGGING
+#  endif
+#endif
+
+#ifdef PERL_IN_XSUB_RE
+/* We *really* need to overwrite these symbols: */
+#  define Perl_pregcomp my_regcomp
+#  define Perl_regdump my_regdump
+#  define Perl_regprop my_regprop
+/* *These* symbols are masked to allow static link. */
+#  define Perl_pregfree my_regfree
+#  define Perl_regnext my_regnext
+#endif 
+
+/*SUPPRESS 112*/
+/*
+ * pregcomp and pregexec -- regsub and regerror are not used in perl
+ *
+ *	Copyright (c) 1986 by University of Toronto.
+ *	Written by Henry Spencer.  Not derived from licensed software.
+ *
+ *	Permission is granted to anyone to use this software for any
+ *	purpose on any computer system, and to redistribute it freely,
+ *	subject to the following restrictions:
+ *
+ *	1. The author is not responsible for the consequences of use of
+ *		this software, no matter how awful, even if they arise
+ *		from defects in it.
+ *
+ *	2. The origin of this software must not be misrepresented, either
+ *		by explicit claim or by omission.
+ *
+ *	3. Altered versions must be plainly marked as such, and must not
+ *		be misrepresented as being the original software.
+ *
+ *
+ ****    Alterations to Henry's code are...
+ ****
+ ****    Copyright (c) 1991-1997, Larry Wall
+ ****
+ ****    You may distribute under the terms of either the GNU General Public
+ ****    License or the Artistic License, as specified in the README file.
+
+ *
+ * Beware that some of this code is subtly aware of the way operator
+ * precedence is structured in regular expressions.  Serious changes in
+ * regular-expression syntax might require a total rethink.
+ */
+#include "EXTERN.h"
+#include "perl.h"
+
+#ifndef PERL_IN_XSUB_RE
+#  include "INTERN.h"
+#endif
+
+#define REG_COMP_C
+#include "regcomp.h"
+
+#ifdef op
+#undef op
+#endif /* op */
+
+#ifdef MSDOS
+# if defined(BUGGY_MSC6)
+ /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
+ # pragma optimize("a",off)
+ /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
+ # pragma optimize("w",on )
+# endif /* BUGGY_MSC6 */
+#endif /* MSDOS */
+
+#ifndef STATIC
+#define	STATIC	static
+#endif
+
+#define	ISMULT1(c)	((c) == '*' || (c) == '+' || (c) == '?')
+#define	ISMULT2(s)	((*s) == '*' || (*s) == '+' || (*s) == '?' || \
+	((*s) == '{' && regcurly(s)))
+#ifdef atarist
+#define	PERL_META	"^$.[()|?+*\\"
+#else
+#define	META	"^$.[()|?+*\\"
+#endif
+
+#ifdef SPSTART
+#undef SPSTART		/* dratted cpp namespace... */
+#endif
+/*
+ * Flags to be passed up and down.
+ */
+#define	WORST		0	/* Worst case. */
+#define	HASWIDTH	0x1	/* Known to match non-null strings. */
+#define	SIMPLE		0x2	/* Simple enough to be STAR/PLUS operand. */
+#define	SPSTART		0x4	/* Starts with * or +. */
+#define TRYAGAIN	0x8	/* Weeded out a declaration. */
+
+/*
+ * Forward declarations for pregcomp()'s friends.
+ */
+
+#ifndef PERL_OBJECT
+static regnode *reg _((I32, I32 *));
+static regnode *reganode _((U8, U32));
+static regnode *regatom _((I32 *));
+static regnode *regbranch _((I32 *, I32));
+static void regc _((U8, char *));
+static regnode *regclass _((void));
+STATIC I32 regcurly _((char *));
+static regnode *reg_node _((U8));
+static regnode *regpiece _((I32 *));
+static void reginsert _((U8, regnode *));
+static void regoptail _((regnode *, regnode *));
+static void regtail _((regnode *, regnode *));
+static char* regwhite _((char *, char *));
+static char* nextchar _((void));
+static void re_croak2 _((const char* pat1,const char* pat2,...)) __attribute__((noreturn));
+#endif
+
+/* Length of a variant. */
+
+#ifndef PERL_OBJECT
+typedef struct {
+    I32 len_min;
+    I32 len_delta;
+    I32 pos_min;
+    I32 pos_delta;
+    SV *last_found;
+    I32 last_end;			/* min value, <0 unless valid. */
+    I32 last_start_min;
+    I32 last_start_max;
+    SV **longest;			/* Either &l_fixed, or &l_float. */
+    SV *longest_fixed;
+    I32 offset_fixed;
+    SV *longest_float;
+    I32 offset_float_min;
+    I32 offset_float_max;
+    I32 flags;
+} scan_data_t;
+#endif
+
+static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+#define SF_BEFORE_EOL		(SF_BEFORE_SEOL|SF_BEFORE_MEOL)
+#define SF_BEFORE_SEOL		0x1
+#define SF_BEFORE_MEOL		0x2
+#define SF_FIX_BEFORE_EOL	(SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
+#define SF_FL_BEFORE_EOL	(SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
+
+#ifdef NO_UNARY_PLUS
+#  define SF_FIX_SHIFT_EOL	(0+2)
+#  define SF_FL_SHIFT_EOL		(0+4)
+#else
+#  define SF_FIX_SHIFT_EOL	(+2)
+#  define SF_FL_SHIFT_EOL		(+4)
+#endif
+
+#define SF_FIX_BEFORE_SEOL	(SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
+#define SF_FIX_BEFORE_MEOL	(SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
+
+#define SF_FL_BEFORE_SEOL	(SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
+#define SF_FL_BEFORE_MEOL	(SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
+#define SF_IS_INF		0x40
+#define SF_HAS_PAR		0x80
+#define SF_IN_PAR		0x100
+#define SF_HAS_EVAL		0x200
+#define SCF_DO_SUBSTR		0x400
+
+STATIC void
+scan_commit(scan_data_t *data)
+{
+    STRLEN l = SvCUR(data->last_found);
+    STRLEN old_l = SvCUR(*data->longest);
+    
+    if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
+	sv_setsv(*data->longest, data->last_found);
+	if (*data->longest == data->longest_fixed) {
+	    data->offset_fixed = l ? data->last_start_min : data->pos_min;
+	    if (data->flags & SF_BEFORE_EOL)
+		data->flags 
+		    |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
+	    else
+		data->flags &= ~SF_FIX_BEFORE_EOL;
+	} else {
+	    data->offset_float_min = l ? data->last_start_min : data->pos_min;
+	    data->offset_float_max = (l 
+				      ? data->last_start_max 
+				      : data->pos_min + data->pos_delta);
+	    if (data->flags & SF_BEFORE_EOL)
+		data->flags 
+		    |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
+	    else
+		data->flags &= ~SF_FL_BEFORE_EOL;
+	}
+    }
+    SvCUR_set(data->last_found, 0);
+    data->last_end = -1;
+    data->flags &= ~SF_BEFORE_EOL;
+}
+
+/* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
+   to the position after last scanned or to NULL. */
+
+STATIC I32
+study_chunk(regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
+			/* scanp: Start here (read-write). */
+			/* deltap: Write maxlen-minlen here. */
+			/* last: Stop before this one. */
+{
+    dTHR;
+    I32 min = 0, pars = 0, code;
+    regnode *scan = *scanp, *next;
+    I32 delta = 0;
+    int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
+    I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
+    scan_data_t data_fake;
+    
+    while (scan && OP(scan) != END && scan < last) {
+	/* Peephole optimizer: */
+
+	if (regkind[(U8)OP(scan)] == EXACT) {
+	    regnode *n = regnext(scan);
+	    U32 stringok = 1;
+#ifdef DEBUGGING
+	    regnode *stop = scan;
+#endif 
+
+	    next = scan + (*OPERAND(scan) + 2 - 1)/sizeof(regnode) + 2;
+	    /* Skip NOTHING, merge EXACT*. */
+	    while (n &&
+		   ( regkind[(U8)OP(n)] == NOTHING || 
+		     (stringok && (OP(n) == OP(scan))))
+		   && NEXT_OFF(n)
+		   && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
+		if (OP(n) == TAIL || n > next)
+		    stringok = 0;
+		if (regkind[(U8)OP(n)] == NOTHING) {
+		    NEXT_OFF(scan) += NEXT_OFF(n);
+		    next = n + NODE_STEP_REGNODE;
+#ifdef DEBUGGING
+		    if (stringok)
+			stop = n;
+#endif 
+		    n = regnext(n);
+		} else {
+		    int oldl = *OPERAND(scan);
+		    regnode *nnext = regnext(n);
+		    
+		    if (oldl + *OPERAND(n) > U8_MAX) 
+			break;
+		    NEXT_OFF(scan) += NEXT_OFF(n);
+		    *OPERAND(scan) += *OPERAND(n);
+		    next = n + (*OPERAND(n) + 2 - 1)/sizeof(regnode) + 2;
+		    /* Now we can overwrite *n : */
+		    Move(OPERAND(n) + 1, OPERAND(scan) + oldl + 1,
+			 *OPERAND(n) + 1, char);
+#ifdef DEBUGGING
+		    if (stringok)
+			stop = next - 1;
+#endif 
+		    n = nnext;
+		}
+	    }
+#ifdef DEBUGGING
+	    /* Allow dumping */
+	    n = scan + (*OPERAND(scan) + 2 - 1)/sizeof(regnode) + 2;
+	    while (n <= stop) {
+		/* Purify reports a benign UMR here sometimes, because we
+		 * don't initialize the OP() slot of a node when that node
+		 * is occupied by just the trailing null of the string in
+		 * an EXACT node */
+		if (regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
+		    OP(n) = OPTIMIZED;
+		    NEXT_OFF(n) = 0;
+		}
+		n++;
+	    }
+#endif 
+
+	}
+	if (OP(scan) != CURLYX) {
+	    int max = (reg_off_by_arg[OP(scan)]
+		       ? I32_MAX
+		       /* I32 may be smaller than U16 on CRAYs! */
+		       : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
+	    int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
+	    int noff;
+	    regnode *n = scan;
+	    
+	    /* Skip NOTHING and LONGJMP. */
+	    while ((n = regnext(n))
+		   && ((regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
+		       || ((OP(n) == LONGJMP) && (noff = ARG(n))))
+		   && off + noff < max)
+		off += noff;
+	    if (reg_off_by_arg[OP(scan)])
+		ARG(scan) = off;
+	    else 
+		NEXT_OFF(scan) = off;
+	}
+	if (OP(scan) == BRANCH || OP(scan) == BRANCHJ 
+		   || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
+	    next = regnext(scan);
+	    code = OP(scan);
+	    
+	    if (OP(next) == code || code == IFTHEN || code == SUSPEND) { 
+		I32 max1 = 0, min1 = I32_MAX, num = 0;
+		
+		if (flags & SCF_DO_SUBSTR)
+		    scan_commit(data);
+		while (OP(scan) == code) {
+		    I32 deltanext, minnext;
+
+		    num++;
+		    data_fake.flags = 0;
+		    next = regnext(scan);
+		    scan = NEXTOPER(scan);
+		    if (code != BRANCH)
+			scan = NEXTOPER(scan);
+		    /* We suppose the run is continuous, last=next...*/
+		    minnext = study_chunk(&scan, &deltanext, next,
+					  &data_fake, 0);
+		    if (min1 > minnext) 
+			min1 = minnext;
+		    if (max1 < minnext + deltanext)
+			max1 = minnext + deltanext;
+		    if (deltanext == I32_MAX)
+			is_inf = 1;
+		    scan = next;
+		    if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+			pars++;
+		    if (data && (data_fake.flags & SF_HAS_EVAL))
+			data->flags |= SF_HAS_EVAL;
+		    if (code == SUSPEND) 
+			break;
+		}
+		if (code == IFTHEN && num < 2) /* Empty ELSE branch */
+		    min1 = 0;
+		if (flags & SCF_DO_SUBSTR) {
+		    data->pos_min += min1;
+		    data->pos_delta += max1 - min1;
+		    if (max1 != min1 || is_inf)
+			data->longest = &(data->longest_float);
+		}
+		min += min1;
+		delta += max1 - min1;
+	    } else if (code == BRANCHJ)	/* single branch is optimized. */
+		scan = NEXTOPER(NEXTOPER(scan));
+	    else			/* single branch is optimized. */
+		scan = NEXTOPER(scan);
+	    continue;
+	} else if (OP(scan) == EXACT) {
+	    min += *OPERAND(scan);
+	    if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
+		I32 l = *OPERAND(scan);
+
+		/* The code below prefers earlier match for fixed
+		   offset, later match for variable offset.  */
+		if (data->last_end == -1) { /* Update the start info. */
+		    data->last_start_min = data->pos_min;
+ 		    data->last_start_max = is_inf
+ 			? I32_MAX : data->pos_min + data->pos_delta; 
+		}
+		sv_catpvn(data->last_found, (char *)(OPERAND(scan)+1), l);
+		data->last_end = data->pos_min + l;
+		data->pos_min += l; /* As in the first entry. */
+		data->flags &= ~SF_BEFORE_EOL;
+	    }
+	} else if (regkind[(U8)OP(scan)] == EXACT) {
+	    if (flags & SCF_DO_SUBSTR) 
+		scan_commit(data);
+	    min += *OPERAND(scan);
+	    if (data && (flags & SCF_DO_SUBSTR))
+		data->pos_min += *OPERAND(scan);
+	} else if (strchr(varies,OP(scan))) {
+	    I32 mincount, maxcount, minnext, deltanext, pos_before, fl;
+	    regnode *oscan = scan;
+	    
+	    switch (regkind[(U8)OP(scan)]) {
+	    case WHILEM:
+		scan = NEXTOPER(scan);
+		goto finish;
+	    case PLUS:
+		if (flags & SCF_DO_SUBSTR) {
+		    next = NEXTOPER(scan);
+		    if (OP(next) == EXACT) {
+			mincount = 1; 
+			maxcount = REG_INFTY; 
+			next = regnext(scan);
+			scan = NEXTOPER(scan);
+			goto do_curly;
+		    }
+		}
+		if (flags & SCF_DO_SUBSTR)
+		    data->pos_min++;
+		min++;
+		/* Fall through. */
+	    case STAR:
+		is_inf = 1; 
+		scan = regnext(scan);
+		if (flags & SCF_DO_SUBSTR) {
+		    scan_commit(data);
+		    data->longest = &(data->longest_float);
+		}
+		goto optimize_curly_tail;
+	    case CURLY:
+		mincount = ARG1(scan); 
+		maxcount = ARG2(scan);
+		next = regnext(scan);
+		scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
+	      do_curly:
+		if (flags & SCF_DO_SUBSTR) {
+		    if (mincount == 0) scan_commit(data);
+		    pos_before = data->pos_min;
+		}
+		if (data) {
+		    fl = data->flags;
+		    data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
+		    if (is_inf)
+			data->flags |= SF_IS_INF;
+		}
+		/* This will finish on WHILEM, setting scan, or on NULL: */
+		minnext = study_chunk(&scan, &deltanext, last, data, 
+				      mincount == 0 
+					? (flags & ~SCF_DO_SUBSTR) : flags);
+		if (!scan) 		/* It was not CURLYX, but CURLY. */
+		    scan = next;
+		if (PL_dowarn && (minnext + deltanext == 0) 
+		    && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
+		    && maxcount <= 10000) /* Complement check for big count */
+		    warn("Strange *+?{} on zero-length expression");
+		min += minnext * mincount;
+		is_inf |= (maxcount == REG_INFTY && (minnext + deltanext) > 0
+			   || deltanext == I32_MAX);
+		delta += (minnext + deltanext) * maxcount - minnext * mincount;
+
+		/* Try powerful optimization CURLYX => CURLYN. */
+		if (  OP(oscan) == CURLYX && data 
+		      && data->flags & SF_IN_PAR
+		      && !(data->flags & SF_HAS_EVAL)
+		      && !deltanext && minnext == 1 ) {
+		    /* Try to optimize to CURLYN.  */
+		    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
+		    regnode *nxt1 = nxt, *nxt2;
+
+		    /* Skip open. */
+		    nxt = regnext(nxt);
+		    if (!strchr(simple,OP(nxt))
+			&& !(regkind[(U8)OP(nxt)] == EXACT
+			     && *OPERAND(nxt) == 1)) 
+			goto nogo;
+		    nxt2 = nxt;
+		    nxt = regnext(nxt);
+		    if (OP(nxt) != CLOSE) 
+			goto nogo;
+		    /* Now we know that nxt2 is the only contents: */
+		    oscan->flags = ARG(nxt);
+		    OP(oscan) = CURLYN;
+		    OP(nxt1) = NOTHING;	/* was OPEN. */
+#ifdef DEBUGGING
+		    OP(nxt1 + 1) = OPTIMIZED; /* was count. */
+		    NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
+		    NEXT_OFF(nxt2) = 0;	/* just for consistancy with CURLY. */
+		    OP(nxt) = OPTIMIZED;	/* was CLOSE. */
+		    OP(nxt + 1) = OPTIMIZED; /* was count. */
+		    NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
+#endif 
+		}
+	      nogo:
+
+		/* Try optimization CURLYX => CURLYM. */
+		if (  OP(oscan) == CURLYX && data 
+		      && !(data->flags & SF_HAS_PAR)
+		      && !(data->flags & SF_HAS_EVAL)
+		      && !deltanext  ) {
+		    /* XXXX How to optimize if data == 0? */
+		    /* Optimize to a simpler form.  */
+		    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
+		    regnode *nxt2;
+
+		    OP(oscan) = CURLYM;
+		    while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
+			    && (OP(nxt2) != WHILEM)) 
+			nxt = nxt2;
+		    OP(nxt2)  = SUCCEED; /* Whas WHILEM */
+		    /* Need to optimize away parenths. */
+		    if (data->flags & SF_IN_PAR) {
+			/* Set the parenth number.  */
+			regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
+
+			if (OP(nxt) != CLOSE) 
+			    FAIL("panic opt close");
+			oscan->flags = ARG(nxt);
+			OP(nxt1) = OPTIMIZED;	/* was OPEN. */
+			OP(nxt) = OPTIMIZED;	/* was CLOSE. */
+#ifdef DEBUGGING
+			OP(nxt1 + 1) = OPTIMIZED; /* was count. */
+			OP(nxt + 1) = OPTIMIZED; /* was count. */
+			NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
+			NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
+#endif 
+#if 0
+			while ( nxt1 && (OP(nxt1) != WHILEM)) {
+			    regnode *nnxt = regnext(nxt1);
+			    
+			    if (nnxt == nxt) {
+				if (reg_off_by_arg[OP(nxt1)])
+				    ARG_SET(nxt1, nxt2 - nxt1);
+				else if (nxt2 - nxt1 < U16_MAX)
+				    NEXT_OFF(nxt1) = nxt2 - nxt1;
+				else
+				    OP(nxt) = NOTHING;	/* Cannot beautify */
+			    }
+			    nxt1 = nnxt;
+			}
+#endif
+			/* Optimize again: */
+			study_chunk(&nxt1, &deltanext, nxt, NULL, 0);
+		    } else
+			oscan->flags = 0;
+		}
+		if (data && fl & (SF_HAS_PAR|SF_IN_PAR)) 
+		    pars++;
+		if (flags & SCF_DO_SUBSTR) {
+		    SV *last_str = Nullsv;
+		    int counted = mincount != 0;
+
+		    if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
+			I32 b = pos_before >= data->last_start_min 
+			    ? pos_before : data->last_start_min;
+			STRLEN l;
+			char *s = SvPV(data->last_found, l);
+			
+			l -= b - data->last_start_min;
+			/* Get the added string: */
+			last_str = newSVpv(s  +  b - data->last_start_min, l);
+			if (deltanext == 0 && pos_before == b) {
+			    /* What was added is a constant string */
+			    if (mincount > 1) {
+				SvGROW(last_str, (mincount * l) + 1);
+				repeatcpy(SvPVX(last_str) + l, 
+					  SvPVX(last_str), l, mincount - 1);
+				SvCUR(last_str) *= mincount;
+				/* Add additional parts. */
+				SvCUR_set(data->last_found, 
+					  SvCUR(data->last_found) - l);
+				sv_catsv(data->last_found, last_str);
+				data->last_end += l * (mincount - 1);
+			    }
+			}
+		    }
+		    /* It is counted once already... */
+		    data->pos_min += minnext * (mincount - counted);
+		    data->pos_delta += - counted * deltanext +
+			(minnext + deltanext) * maxcount - minnext * mincount;
+		    if (mincount != maxcount) {
+			scan_commit(data);
+			if (mincount && last_str) {
+			    sv_setsv(data->last_found, last_str);
+			    data->last_end = data->pos_min;
+			    data->last_start_min = 
+				data->pos_min - SvCUR(last_str);
+			    data->last_start_max = is_inf 
+				? I32_MAX 
+				: data->pos_min + data->pos_delta
+				- SvCUR(last_str);
+			}
+			data->longest = &(data->longest_float);
+		    }
+		}
+		if (data && (fl & SF_HAS_EVAL))
+		    data->flags |= SF_HAS_EVAL;
+	      optimize_curly_tail:
+		if (OP(oscan) != CURLYX) {
+		    while (regkind[(U8)OP(next = regnext(oscan))] == NOTHING
+			   && NEXT_OFF(next))
+			NEXT_OFF(oscan) += NEXT_OFF(next);
+		}
+		continue;
+	    default:			/* REF only? */
+		if (flags & SCF_DO_SUBSTR) {
+		    scan_commit(data);
+		    data->longest = &(data->longest_float);
+		}
+		is_inf = 1;
+		break;
+	    }
+	} else if (strchr(simple,OP(scan))) {
+	    if (flags & SCF_DO_SUBSTR) {
+		scan_commit(data);
+		data->pos_min++;
+	    }
+	    min++;
+	} else if (regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
+	    data->flags |= (OP(scan) == MEOL
+			    ? SF_BEFORE_MEOL
+			    : SF_BEFORE_SEOL);
+	} else if (regkind[(U8)OP(scan)] == BRANCHJ
+		   && (scan->flags || data)
+		   && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
+	    I32 deltanext, minnext;
+	    regnode *nscan;
+
+	    data_fake.flags = 0;
+	    next = regnext(scan);
+	    nscan = NEXTOPER(NEXTOPER(scan));
+	    minnext = study_chunk(&nscan, &deltanext, last, &data_fake, 0);
+	    if (scan->flags) {
+		if (deltanext) {
+		    FAIL("variable length lookbehind not implemented");
+		} else if (minnext > U8_MAX) {
+		    FAIL2("lookbehind longer than %d not implemented", U8_MAX);
+		}
+		scan->flags = minnext;
+	    }
+	    if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
+		pars++;
+	    if (data && (data_fake.flags & SF_HAS_EVAL))
+		data->flags |= SF_HAS_EVAL;
+	} else if (OP(scan) == OPEN) {
+	    pars++;
+	} else if (OP(scan) == CLOSE && ARG(scan) == is_par) {
+	    next = regnext(scan);
+
+	    if ( next && (OP(next) != WHILEM) && next < last)
+		is_par = 0;		/* Disable optimization */
+	} else if (OP(scan) == EVAL) {
+		if (data)
+		    data->flags |= SF_HAS_EVAL;
+	}
+	/* Else: zero-length, ignore. */
+	scan = regnext(scan);
+    }
+
+  finish:
+    *scanp = scan;
+    *deltap = is_inf ? I32_MAX : delta;
+    if (flags & SCF_DO_SUBSTR && is_inf) 
+	data->pos_delta = I32_MAX - data->pos_min;
+    if (is_par > U8_MAX)
+	is_par = 0;
+    if (is_par && pars==1 && data) {
+	data->flags |= SF_IN_PAR;
+	data->flags &= ~SF_HAS_PAR;
+    } else if (pars && data) {
+	data->flags |= SF_HAS_PAR;
+	data->flags &= ~SF_IN_PAR;
+    }
+    return min;
+}
+
+STATIC I32
+add_data(I32 n, char *s)
+{
+    dTHR;
+    if (PL_regcomp_rx->data) {
+	Renewc(PL_regcomp_rx->data, 
+	       sizeof(*PL_regcomp_rx->data) + sizeof(void*) * (PL_regcomp_rx->data->count + n - 1), 
+	       char, struct reg_data);
+	Renew(PL_regcomp_rx->data->what, PL_regcomp_rx->data->count + n, U8);
+	PL_regcomp_rx->data->count += n;
+    } else {
+	Newc(1207, PL_regcomp_rx->data, sizeof(*PL_regcomp_rx->data) + sizeof(void*) * (n - 1),
+	     char, struct reg_data);
+	New(1208, PL_regcomp_rx->data->what, n, U8);
+	PL_regcomp_rx->data->count = n;
+    }
+    Copy(s, PL_regcomp_rx->data->what + PL_regcomp_rx->data->count - n, n, U8);
+    return PL_regcomp_rx->data->count - n;
+}
+
+/*
+ - pregcomp - compile a regular expression into internal code
+ *
+ * We can't allocate space until we know how big the compiled form will be,
+ * but we can't compile it (and thus know how big it is) until we've got a
+ * place to put the code.  So we cheat:  we compile it twice, once with code
+ * generation turned off and size counting turned on, and once "for real".
+ * This also means that we don't allocate space until we are sure that the
+ * thing really will compile successfully, and we never have to move the
+ * code and thus invalidate pointers into it.  (Note that it has to be in
+ * one piece because free() must be able to free it all.) [NB: not true in perl]
+ *
+ * Beware that the optimization-preparation code in here knows about some
+ * of the structure of the compiled regexp.  [I'll say.]
+ */
+regexp *
+pregcomp(char *exp, char *xend, PMOP *pm)
+{
+    dTHR;
+    register regexp *r;
+    regnode *scan;
+    SV **longest;
+    SV *longest_fixed;
+    SV *longest_float;
+    regnode *first;
+    I32 flags;
+    I32 minlen = 0;
+    I32 sawplus = 0;
+    I32 sawopen = 0;
+
+    if (exp == NULL)
+	FAIL("NULL regexp argument");
+
+    PL_regprecomp = savepvn(exp, xend - exp);
+    DEBUG_r(PerlIO_printf(Perl_debug_log, "compiling RE `%*s'\n",
+			  xend - exp, PL_regprecomp));
+    PL_regflags = pm->op_pmflags;
+    PL_regsawback = 0;
+
+    PL_regseen = 0;
+    PL_seen_zerolen = *exp == '^' ? -1 : 0;
+    PL_seen_evals = 0;
+    PL_extralen = 0;
+
+    /* First pass: determine size, legality. */
+    PL_regcomp_parse = exp;
+    PL_regxend = xend;
+    PL_regnaughty = 0;
+    PL_regnpar = 1;
+    PL_regsize = 0L;
+    PL_regcode = &PL_regdummy;
+    regc((U8)MAGIC, (char*)PL_regcode);
+    if (reg(0, &flags) == NULL) {
+	Safefree(PL_regprecomp);
+	PL_regprecomp = Nullch;
+	return(NULL);
+    }
+    DEBUG_r(PerlIO_printf(Perl_debug_log, "size %d ", PL_regsize));
+
+    DEBUG_r(
+	if (!PL_colorset) {
+	    int i = 0;
+	    char *s = PerlEnv_getenv("TERMCAP_COLORS");
+	    
+	    PL_colorset = 1;
+	    if (s) {
+		PL_colors[0] = s = savepv(s);
+		while (++i < 4) {
+		    s = strchr(s, '\t');
+		    if (!s) 
+			FAIL("Not enough TABs in TERMCAP_COLORS");
+		    *s = '\0';
+		    PL_colors[i] = ++s;
+		}
+	    } else {
+		while (i < 4) 
+		    PL_colors[i++] = "";
+	    }
+	    /* Reset colors: */
+	    PerlIO_printf(Perl_debug_log, "%s%s%s%s", 
+			  PL_colors[0],PL_colors[1],PL_colors[2],PL_colors[3]);
+	}
+	);
+
+    /* Small enough for pointer-storage convention?
+       If extralen==0, this means that we will not need long jumps. */
+    if (PL_regsize >= 0x10000L && PL_extralen)
+        PL_regsize += PL_extralen;
+    else
+	PL_extralen = 0;
+
+    /* Allocate space and initialize. */
+    Newc(1001, r, sizeof(regexp) + (unsigned)PL_regsize * sizeof(regnode),
+	 char, regexp);
+    if (r == NULL)
+	FAIL("regexp out of space");
+    r->refcnt = 1;
+    r->prelen = xend - exp;
+    r->precomp = PL_regprecomp;
+    r->subbeg = r->subbase = NULL;
+    r->nparens = PL_regnpar - 1;		/* set early to validate backrefs */
+    PL_regcomp_rx = r;
+
+    /* Second pass: emit code. */
+    PL_regcomp_parse = exp;
+    PL_regxend = xend;
+    PL_regnaughty = 0;
+    PL_regnpar = 1;
+    PL_regcode = r->program;
+    /* Store the count of eval-groups for security checks: */
+    PL_regcode->next_off = ((PL_seen_evals > U16_MAX) ? U16_MAX : PL_seen_evals);
+    regc((U8)MAGIC, (char*) PL_regcode++);
+    r->data = 0;
+    if (reg(0, &flags) == NULL)
+	return(NULL);
+
+    /* Dig out information for optimizations. */
+    r->reganch = pm->op_pmflags & PMf_COMPILETIME;
+    pm->op_pmflags = PL_regflags;
+    r->regstclass = NULL;
+    r->naughty = PL_regnaughty >= 10;	/* Probably an expensive pattern. */
+    scan = r->program + 1;		/* First BRANCH. */
+
+    /* XXXX To minimize changes to RE engine we always allocate
+       3-units-long substrs field. */
+    Newz(1004, r->substrs, 1, struct reg_substr_data);
+
+    if (OP(scan) != BRANCH) {	/* Only one top-level choice. */
+	scan_data_t data;
+	I32 fake;
+	STRLEN longest_float_length, longest_fixed_length;
+
+	StructCopy(&zero_scan_data, &data, scan_data_t);
+	first = scan;
+	/* Skip introductions and multiplicators >= 1. */
+	while ((OP(first) == OPEN && (sawopen = 1)) ||
+	    (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
+	    (OP(first) == PLUS) ||
+	    (OP(first) == MINMOD) ||
+	    (regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
+		if (OP(first) == PLUS)
+		    sawplus = 1;
+		else
+		    first += regarglen[(U8)OP(first)];
+		first = NEXTOPER(first);
+	}
+
+	/* Starting-point info. */
+      again:
+	if (OP(first) == EXACT);	/* Empty, get anchored substr later. */
+	else if (strchr(simple+2,OP(first)))
+	    r->regstclass = first;
+	else if (regkind[(U8)OP(first)] == BOUND ||
+		 regkind[(U8)OP(first)] == NBOUND)
+	    r->regstclass = first;
+	else if (regkind[(U8)OP(first)] == BOL) {
+	    r->reganch |= (OP(first) == MBOL ? ROPT_ANCH_MBOL: ROPT_ANCH_BOL);
+	    first = NEXTOPER(first);
+	    goto again;
+	}
+	else if (OP(first) == GPOS) {
+	    r->reganch |= ROPT_ANCH_GPOS;
+	    first = NEXTOPER(first);
+	    goto again;
+	}
+	else if ((OP(first) == STAR &&
+	    regkind[(U8)OP(NEXTOPER(first))] == ANY) &&
+	    !(r->reganch & ROPT_ANCH) )
+	{
+	    /* turn .* into ^.* with an implied $*=1 */
+	    r->reganch |= ROPT_ANCH_BOL | ROPT_IMPLICIT;
+	    first = NEXTOPER(first);
+	    goto again;
+	}
+	if (sawplus && (!sawopen || !PL_regsawback))
+	    r->reganch |= ROPT_SKIP;	/* x+ must match 1st of run */
+
+	/* Scan is after the zeroth branch, first is atomic matcher. */
+	DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %d\n", 
+			      first - scan + 1));
+	/*
+	* If there's something expensive in the r.e., find the
+	* longest literal string that must appear and make it the
+	* regmust.  Resolve ties in favor of later strings, since
+	* the regstart check works with the beginning of the r.e.
+	* and avoiding duplication strengthens checking.  Not a
+	* strong reason, but sufficient in the absence of others.
+	* [Now we resolve ties in favor of the earlier string if
+	* it happens that c_offset_min has been invalidated, since the
+	* earlier string may buy us something the later one won't.]
+	*/
+	minlen = 0;
+
+	data.longest_fixed = newSVpv("",0);
+	data.longest_float = newSVpv("",0);
+	data.last_found = newSVpv("",0);
+	data.longest = &(data.longest_fixed);
+	first = scan;
+	
+	minlen = study_chunk(&first, &fake, scan + PL_regsize, /* Up to end */
+			     &data, SCF_DO_SUBSTR);
+	if ( PL_regnpar == 1 && data.longest == &(data.longest_fixed)
+	     && data.last_start_min == 0 && data.last_end > 0 
+	     && !PL_seen_zerolen
+	     && (!(PL_regseen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
+	    r->reganch |= ROPT_CHECK_ALL;
+	scan_commit(&data);
+	SvREFCNT_dec(data.last_found);
+
+	longest_float_length = SvCUR(data.longest_float);
+	if (longest_float_length
+	    || (data.flags & SF_FL_BEFORE_EOL
+		&& (!(data.flags & SF_FL_BEFORE_MEOL)
+		    || (PL_regflags & PMf_MULTILINE)))) {
+	    if (SvCUR(data.longest_fixed) 
+		&& data.offset_fixed == data.offset_float_min)
+		goto remove;		/* Like in (a)+. */
+	    
+	    r->float_substr = data.longest_float;
+	    r->float_min_offset = data.offset_float_min;
+	    r->float_max_offset = data.offset_float_max;
+	    fbm_compile(r->float_substr, 0);
+	    BmUSEFUL(r->float_substr) = 100;
+	    if (data.flags & SF_FL_BEFORE_EOL /* Cannot have SEOL and MULTI */
+		&& (!(data.flags & SF_FL_BEFORE_MEOL)
+		    || (PL_regflags & PMf_MULTILINE))) 
+		SvTAIL_on(r->float_substr);
+	} else {
+	  remove:
+	    r->float_substr = Nullsv;
+	    SvREFCNT_dec(data.longest_float);
+	    longest_float_length = 0;
+	}
+
+	longest_fixed_length = SvCUR(data.longest_fixed);
+	if (longest_fixed_length
+	    || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
+		&& (!(data.flags & SF_FIX_BEFORE_MEOL)
+		    || (PL_regflags & PMf_MULTILINE)))) {
+	    r->anchored_substr = data.longest_fixed;
+	    r->anchored_offset = data.offset_fixed;
+	    fbm_compile(r->anchored_substr, 0);
+	    BmUSEFUL(r->anchored_substr) = 100;
+	    if (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
+		&& (!(data.flags & SF_FIX_BEFORE_MEOL)
+		    || (PL_regflags & PMf_MULTILINE)))
+		SvTAIL_on(r->anchored_substr);
+	} else {
+	    r->anchored_substr = Nullsv;
+	    SvREFCNT_dec(data.longest_fixed);
+	    longest_fixed_length = 0;
+	}
+
+	/* A temporary algorithm prefers floated substr to fixed one to dig more info. */
+	if (longest_fixed_length > longest_float_length) {
+	    r->check_substr = r->anchored_substr;
+	    r->check_offset_min = r->check_offset_max = r->anchored_offset;
+	    if (r->reganch & ROPT_ANCH_SINGLE)
+		r->reganch |= ROPT_NOSCAN;
+	} else {
+	    r->check_substr = r->float_substr;
+	    r->check_offset_min = data.offset_float_min;
+	    r->check_offset_max = data.offset_float_max;
+	}
+    } else {
+	/* Several toplevels. Best we can is to set minlen. */
+	I32 fake;
+	
+	DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
+	scan = r->program + 1;
+	minlen = study_chunk(&scan, &fake, scan + PL_regsize, NULL, 0);
+	r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
+    }
+
+    r->minlen = minlen;
+    if (PL_regseen & REG_SEEN_GPOS) 
+	r->reganch |= ROPT_GPOS_SEEN;
+    if (PL_regseen & REG_SEEN_LOOKBEHIND)
+	r->reganch |= ROPT_LOOKBEHIND_SEEN;
+    if (PL_regseen & REG_SEEN_EVAL)
+	r->reganch |= ROPT_EVAL_SEEN;
+    Newz(1002, r->startp, PL_regnpar, char*);
+    Newz(1002, r->endp, PL_regnpar, char*);
+    DEBUG_r(regdump(r));
+    return(r);
+}
+
+/*
+ - reg - regular expression, i.e. main body or parenthesized thing
+ *
+ * Caller must absorb opening parenthesis.
+ *
+ * Combining parenthesis handling with the base level of regular expression
+ * is a trifle forced, but the need to tie the tails of the branches to what
+ * follows makes it hard to avoid.
+ */
+STATIC regnode *
+reg(I32 paren, I32 *flagp)
+    /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
+{
+    dTHR;
+    register regnode *ret;		/* Will be the head of the group. */
+    register regnode *br;
+    register regnode *lastbr;
+    register regnode *ender = 0;
+    register I32 parno = 0;
+    I32 flags, oregflags = PL_regflags, have_branch = 0, open = 0;
+    char c;
+
+    *flagp = 0;				/* Tentatively. */
+
+    /* Make an OPEN node, if parenthesized. */
+    if (paren) {
+	if (*PL_regcomp_parse == '?') {
+	    U16 posflags = 0, negflags = 0;
+	    U16 *flagsp = &posflags;
+
+	    PL_regcomp_parse++;
+	    paren = *PL_regcomp_parse++;
+	    ret = NULL;			/* For look-ahead/behind. */
+	    switch (paren) {
+	    case '<':
+		PL_regseen |= REG_SEEN_LOOKBEHIND;
+		if (*PL_regcomp_parse == '!') 
+		    paren = ',';
+		if (*PL_regcomp_parse != '=' && *PL_regcomp_parse != '!') 
+		    goto unknown;
+		PL_regcomp_parse++;
+	    case '=':
+	    case '!':
+		PL_seen_zerolen++;
+	    case ':':
+	    case '>':
+		break;
+	    case '$':
+	    case '@':
+		FAIL2("Sequence (?%c...) not implemented", (int)paren);
+		break;
+	    case '#':
+		while (*PL_regcomp_parse && *PL_regcomp_parse != ')')
+		    PL_regcomp_parse++;
+		if (*PL_regcomp_parse != ')')
+		    FAIL("Sequence (?#... not terminated");
+		nextchar();
+		*flagp = TRYAGAIN;
+		return NULL;
+	    case '{':
+	    {
+		dTHR;
+		I32 count = 1, n = 0;
+		char c;
+		char *s = PL_regcomp_parse;
+		SV *sv;
+		OP_4tree *sop, *rop;
+
+		PL_seen_zerolen++;
+		PL_regseen |= REG_SEEN_EVAL;
+		while (count && (c = *PL_regcomp_parse)) {
+		    if (c == '\\' && PL_regcomp_parse[1])
+			PL_regcomp_parse++;
+		    else if (c == '{') 
+			count++;
+		    else if (c == '}') 
+			count--;
+		    PL_regcomp_parse++;
+		}
+		if (*PL_regcomp_parse != ')')
+		    FAIL("Sequence (?{...}) not terminated or not {}-balanced");
+		if (!SIZE_ONLY) {
+		    AV *av;
+		    
+		    if (PL_regcomp_parse - 1 - s) 
+			sv = newSVpv(s, PL_regcomp_parse - 1 - s);
+		    else
+			sv = newSVpv("", 0);
+
+		    rop = sv_compile_2op(sv, &sop, "re", &av);
+
+		    n = add_data(3, "nso");
+		    PL_regcomp_rx->data->data[n] = (void*)rop;
+		    PL_regcomp_rx->data->data[n+1] = (void*)av;
+		    PL_regcomp_rx->data->data[n+2] = (void*)sop;
+		    SvREFCNT_dec(sv);
+		} else {		/* First pass */
+		    if (PL_reginterp_cnt < ++PL_seen_evals && PL_curcop != &PL_compiling)
+			/* No compiled RE interpolated, has runtime
+			   components ===> unsafe.  */
+			FAIL("Eval-group not allowed at runtime, use re 'eval'");
+		    if (PL_tainted)
+			FAIL("Eval-group in insecure regular expression");
+		}
+		
+		nextchar();
+		return reganode(EVAL, n);
+	    }
+	    case '(':
+	    {
+		if (PL_regcomp_parse[0] == '?') {
+		    if (PL_regcomp_parse[1] == '=' || PL_regcomp_parse[1] == '!' 
+			|| PL_regcomp_parse[1] == '<' 
+			|| PL_regcomp_parse[1] == '{') { /* Lookahead or eval. */
+			I32 flag;
+			
+			ret = reg_node(LOGICAL);
+			regtail(ret, reg(1, &flag));
+			goto insert_if;
+		    } 
+		} else if (PL_regcomp_parse[0] >= '1' && PL_regcomp_parse[0] <= '9' ) {
+		    parno = atoi(PL_regcomp_parse++);
+
+		    while (isDIGIT(*PL_regcomp_parse))
+			PL_regcomp_parse++;
+		    ret = reganode(GROUPP, parno);
+		    if ((c = *nextchar()) != ')')
+			FAIL2("Switch (?(number%c not recognized", c);
+		  insert_if:
+		    regtail(ret, reganode(IFTHEN, 0));
+		    br = regbranch(&flags, 1);
+		    if (br == NULL)
+			br = reganode(LONGJMP, 0);
+		    else
+			regtail(br, reganode(LONGJMP, 0));
+		    c = *nextchar();
+		    if (c == '|') {
+			lastbr = reganode(IFTHEN, 0); /* Fake one for optimizer. */
+			regbranch(&flags, 1);
+			regtail(ret, lastbr);
+			c = *nextchar();
+		    } else
+			lastbr = NULL;
+		    if (c != ')')
+			FAIL("Switch (?(condition)... contains too many branches");
+		    ender = reg_node(TAIL);
+		    regtail(br, ender);
+		    if (lastbr) {
+			regtail(lastbr, ender);
+			regtail(NEXTOPER(NEXTOPER(lastbr)), ender);
+		    } else
+			regtail(ret, ender);
+		    return ret;
+		} else {
+		    FAIL2("Unknown condition for (?(%.2s", PL_regcomp_parse);
+		}
+	    }
+            case 0:
+                FAIL("Sequence (? incomplete");
+                break;
+	    default:
+		--PL_regcomp_parse;
+	      parse_flags:
+		while (*PL_regcomp_parse && strchr("iogcmsx", *PL_regcomp_parse)) {
+		    if (*PL_regcomp_parse != 'o')
+			pmflag(flagsp, *PL_regcomp_parse);
+		    ++PL_regcomp_parse;
+		}
+		if (*PL_regcomp_parse == '-') {
+		    flagsp = &negflags;
+		    ++PL_regcomp_parse;
+		    goto parse_flags;
+		}
+		PL_regflags |= posflags;
+		PL_regflags &= ~negflags;
+		if (*PL_regcomp_parse == ':') {
+		    PL_regcomp_parse++;
+		    paren = ':';
+		    break;
+		}		
+	      unknown:
+		if (*PL_regcomp_parse != ')')
+		    FAIL2("Sequence (?%c...) not recognized", *PL_regcomp_parse);
+		nextchar();
+		*flagp = TRYAGAIN;
+		return NULL;
+	    }
+	}
+	else {
+	    parno = PL_regnpar;
+	    PL_regnpar++;
+	    ret = reganode(OPEN, parno);
+	    open = 1;
+	}
+    } else
+	ret = NULL;
+
+    /* Pick up the branches, linking them together. */
+    br = regbranch(&flags, 1);
+    if (br == NULL)
+	return(NULL);
+    if (*PL_regcomp_parse == '|') {
+	if (!SIZE_ONLY && PL_extralen) {
+	    reginsert(BRANCHJ, br);
+	} else
+	    reginsert(BRANCH, br);
+	have_branch = 1;
+	if (SIZE_ONLY)
+	    PL_extralen += 1;		/* For BRANCHJ-BRANCH. */
+    } else if (paren == ':') {
+	*flagp |= flags&SIMPLE;
+    }
+    if (open) {				/* Starts with OPEN. */
+	regtail(ret, br);		/* OPEN -> first. */
+    } else if (paren != '?')		/* Not Conditional */
+	ret = br;
+    if (flags&HASWIDTH)
+	*flagp |= HASWIDTH;
+    *flagp |= flags&SPSTART;
+    lastbr = br;
+    while (*PL_regcomp_parse == '|') {
+	if (!SIZE_ONLY && PL_extralen) {
+	    ender = reganode(LONGJMP,0);
+	    regtail(NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
+	}
+	if (SIZE_ONLY)
+	    PL_extralen += 2;		/* Account for LONGJMP. */
+	nextchar();
+	br = regbranch(&flags, 0);
+	if (br == NULL)
+	    return(NULL);
+	regtail(lastbr, br);		/* BRANCH -> BRANCH. */
+	lastbr = br;
+	if (flags&HASWIDTH)
+	    *flagp |= HASWIDTH;
+	*flagp |= flags&SPSTART;
+    }
+
+    if (have_branch || paren != ':') {
+	/* Make a closing node, and hook it on the end. */
+	switch (paren) {
+	case ':':
+	    ender = reg_node(TAIL);
+	    break;
+	case 1:
+	    ender = reganode(CLOSE, parno);
+	    break;
+	case '<':
+	case ',':
+	case '=':
+	case '!':
+	    *flagp &= ~HASWIDTH;
+	    /* FALL THROUGH */
+	case '>':
+	    ender = reg_node(SUCCEED);
+	    break;
+	case 0:
+	    ender = reg_node(END);
+	    break;
+	}
+	regtail(lastbr, ender);
+
+	if (have_branch) {
+	    /* Hook the tails of the branches to the closing node. */
+	    for (br = ret; br != NULL; br = regnext(br)) {
+		regoptail(br, ender);
+	    }
+	}
+    }
+
+    {
+	char *p;
+	static char parens[] = "=!<,>";
+
+	if (paren && (p = strchr(parens, paren))) {
+	    int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
+	    int flag = (p - parens) > 1;
+
+	    if (paren == '>')
+		node = SUSPEND, flag = 0;
+	    reginsert(node,ret);
+	    ret->flags = flag;
+	    regtail(ret, reg_node(TAIL));
+	}
+    }
+
+    /* Check for proper termination. */
+    if (paren && (PL_regcomp_parse >= PL_regxend || *nextchar() != ')')) {
+	FAIL("unmatched () in regexp");
+    } else if (!paren && PL_regcomp_parse < PL_regxend) {
+	if (*PL_regcomp_parse == ')') {
+	    FAIL("unmatched () in regexp");
+	} else
+	    FAIL("junk on end of regexp");	/* "Can't happen". */
+	/* NOTREACHED */
+    }
+    if (paren != 0) {
+	PL_regflags = oregflags;
+    }
+
+    return(ret);
+}
+
+/*
+ - regbranch - one alternative of an | operator
+ *
+ * Implements the concatenation operator.
+ */
+STATIC regnode *
+regbranch(I32 *flagp, I32 first)
+{
+    dTHR;
+    register regnode *ret;
+    register regnode *chain = NULL;
+    register regnode *latest;
+    I32 flags = 0, c = 0;
+
+    if (first) 
+	ret = NULL;
+    else {
+	if (!SIZE_ONLY && PL_extralen) 
+	    ret = reganode(BRANCHJ,0);
+	else
+	    ret = reg_node(BRANCH);
+    }
+	
+    if (!first && SIZE_ONLY) 
+	PL_extralen += 1;			/* BRANCHJ */
+    
+    *flagp = WORST;			/* Tentatively. */
+
+    PL_regcomp_parse--;
+    nextchar();
+    while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != '|' && *PL_regcomp_parse != ')') {
+	flags &= ~TRYAGAIN;
+	latest = regpiece(&flags);
+	if (latest == NULL) {
+	    if (flags & TRYAGAIN)
+		continue;
+	    return(NULL);
+	} else if (ret == NULL)
+	    ret = latest;
+	*flagp |= flags&HASWIDTH;
+	if (chain == NULL) 	/* First piece. */
+	    *flagp |= flags&SPSTART;
+	else {
+	    PL_regnaughty++;
+	    regtail(chain, latest);
+	}
+	chain = latest;
+	c++;
+    }
+    if (chain == NULL) {	/* Loop ran zero times. */
+	chain = reg_node(NOTHING);
+	if (ret == NULL)
+	    ret = chain;
+    }
+    if (c == 1) {
+	*flagp |= flags&SIMPLE;
+    }
+
+    return(ret);
+}
+
+/*
+ - regpiece - something followed by possible [*+?]
+ *
+ * Note that the branching code sequences used for ? and the general cases
+ * of * and + are somewhat optimized:  they use the same NOTHING node as
+ * both the endmarker for their branch list and the body of the last branch.
+ * It might seem that this node could be dispensed with entirely, but the
+ * endmarker role is not redundant.
+ */
+STATIC regnode *
+regpiece(I32 *flagp)
+{
+    dTHR;
+    register regnode *ret;
+    register char op;
+    register char *next;
+    I32 flags;
+    char *origparse = PL_regcomp_parse;
+    char *maxpos;
+    I32 min;
+    I32 max = REG_INFTY;
+
+    ret = regatom(&flags);
+    if (ret == NULL) {
+	if (flags & TRYAGAIN)
+	    *flagp |= TRYAGAIN;
+	return(NULL);
+    }
+
+    op = *PL_regcomp_parse;
+
+    if (op == '{' && regcurly(PL_regcomp_parse)) {
+	next = PL_regcomp_parse + 1;
+	maxpos = Nullch;
+	while (isDIGIT(*next) || *next == ',') {
+	    if (*next == ',') {
+		if (maxpos)
+		    break;
+		else
+		    maxpos = next;
+	    }
+	    next++;
+	}
+	if (*next == '}') {		/* got one */
+	    if (!maxpos)
+		maxpos = next;
+	    PL_regcomp_parse++;
+	    min = atoi(PL_regcomp_parse);
+	    if (*maxpos == ',')
+		maxpos++;
+	    else
+		maxpos = PL_regcomp_parse;
+	    max = atoi(maxpos);
+	    if (!max && *maxpos != '0')
+		max = REG_INFTY;		/* meaning "infinity" */
+	    else if (max >= REG_INFTY)
+		FAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
+	    PL_regcomp_parse = next;
+	    nextchar();
+
+	do_curly:
+	    if ((flags&SIMPLE)) {
+		PL_regnaughty += 2 + PL_regnaughty / 2;
+		reginsert(CURLY, ret);
+	    }
+	    else {
+		PL_regnaughty += 4 + PL_regnaughty;	/* compound interest */
+		regtail(ret, reg_node(WHILEM));
+		if (!SIZE_ONLY && PL_extralen) {
+		    reginsert(LONGJMP,ret);
+		    reginsert(NOTHING,ret);
+		    NEXT_OFF(ret) = 3;	/* Go over LONGJMP. */
+		}
+		reginsert(CURLYX,ret);
+		if (!SIZE_ONLY && PL_extralen)
+		    NEXT_OFF(ret) = 3;	/* Go over NOTHING to LONGJMP. */
+		regtail(ret, reg_node(NOTHING));
+		if (SIZE_ONLY)
+		    PL_extralen += 3;
+	    }
+	    ret->flags = 0;
+
+	    if (min > 0)
+		*flagp = WORST;
+	    if (max > 0)
+		*flagp |= HASWIDTH;
+	    if (max && max < min)
+		FAIL("Can't do {n,m} with n > m");
+	    if (!SIZE_ONLY) {
+		ARG1_SET(ret, min);
+		ARG2_SET(ret, max);
+	    }
+
+	    goto nest_check;
+	}
+    }
+
+    if (!ISMULT1(op)) {
+	*flagp = flags;
+	return(ret);
+    }
+
+#if 0				/* Now runtime fix should be reliable. */
+    if (!(flags&HASWIDTH) && op != '?')
+      FAIL("regexp *+ operand could be empty");
+#endif 
+
+    nextchar();
+
+    *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
+
+    if (op == '*' && (flags&SIMPLE)) {
+	reginsert(STAR, ret);
+	ret->flags = 0;
+	PL_regnaughty += 4;
+    }
+    else if (op == '*') {
+	min = 0;
+	goto do_curly;
+    } else if (op == '+' && (flags&SIMPLE)) {
+	reginsert(PLUS, ret);
+	ret->flags = 0;
+	PL_regnaughty += 3;
+    }
+    else if (op == '+') {
+	min = 1;
+	goto do_curly;
+    } else if (op == '?') {
+	min = 0; max = 1;
+	goto do_curly;
+    }
+  nest_check:
+    if (PL_dowarn && !SIZE_ONLY && !(flags&HASWIDTH) && max > 10000) {
+	warn("%.*s matches null string many times",
+	    PL_regcomp_parse - origparse, origparse);
+    }
+
+    if (*PL_regcomp_parse == '?') {
+	nextchar();
+	reginsert(MINMOD, ret);
+	regtail(ret, ret + NODE_STEP_REGNODE);
+    }
+    if (ISMULT2(PL_regcomp_parse))
+	FAIL("nested *?+ in regexp");
+
+    return(ret);
+}
+
+/*
+ - regatom - the lowest level
+ *
+ * Optimization:  gobbles an entire sequence of ordinary characters so that
+ * it can turn them into a single node, which is smaller to store and
+ * faster to run.  Backslashed characters are exceptions, each becoming a
+ * separate node; the code is simpler that way and it's not worth fixing.
+ *
+ * [Yes, it is worth fixing, some scripts can run twice the speed.]
+ */
+STATIC regnode *
+regatom(I32 *flagp)
+{
+    dTHR;
+    register regnode *ret = 0;
+    I32 flags;
+
+    *flagp = WORST;		/* Tentatively. */
+
+tryagain:
+    switch (*PL_regcomp_parse) {
+    case '^':
+	PL_seen_zerolen++;
+	nextchar();
+	if (PL_regflags & PMf_MULTILINE)
+	    ret = reg_node(MBOL);
+	else if (PL_regflags & PMf_SINGLELINE)
+	    ret = reg_node(SBOL);
+	else
+	    ret = reg_node(BOL);
+	break;
+    case '$':
+	if (PL_regcomp_parse[1]) 
+	    PL_seen_zerolen++;
+	nextchar();
+	if (PL_regflags & PMf_MULTILINE)
+	    ret = reg_node(MEOL);
+	else if (PL_regflags & PMf_SINGLELINE)
+	    ret = reg_node(SEOL);
+	else
+	    ret = reg_node(EOL);
+	break;
+    case '.':
+	nextchar();
+	if (PL_regflags & PMf_SINGLELINE)
+	    ret = reg_node(SANY);
+	else
+	    ret = reg_node(ANY);
+	PL_regnaughty++;
+	*flagp |= HASWIDTH|SIMPLE;
+	break;
+    case '[':
+	PL_regcomp_parse++;
+	ret = regclass();
+	*flagp |= HASWIDTH|SIMPLE;
+	break;
+    case '(':
+	nextchar();
+	ret = reg(1, &flags);
+	if (ret == NULL) {
+		if (flags & TRYAGAIN)
+		    goto tryagain;
+		return(NULL);
+	}
+	*flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
+	break;
+    case '|':
+    case ')':
+	if (flags & TRYAGAIN) {
+	    *flagp |= TRYAGAIN;
+	    return NULL;
+	}
+	FAIL2("internal urp in regexp at /%s/", PL_regcomp_parse);
+				/* Supposed to be caught earlier. */
+	break;
+    case '{':
+	if (!regcurly(PL_regcomp_parse)) {
+	    PL_regcomp_parse++;
+	    goto defchar;
+	}
+	/* FALL THROUGH */
+    case '?':
+    case '+':
+    case '*':
+	FAIL("?+*{} follows nothing in regexp");
+	break;
+    case '\\':
+	switch (*++PL_regcomp_parse) {
+	case 'A':
+	    PL_seen_zerolen++;
+	    ret = reg_node(SBOL);
+	    *flagp |= SIMPLE;
+	    nextchar();
+	    break;
+	case 'G':
+	    ret = reg_node(GPOS);
+	    PL_regseen |= REG_SEEN_GPOS;
+	    *flagp |= SIMPLE;
+	    nextchar();
+	    break;
+	case 'Z':
+	    ret = reg_node(SEOL);
+	    *flagp |= SIMPLE;
+	    nextchar();
+	    break;
+	case 'z':
+	    ret = reg_node(EOS);
+	    *flagp |= SIMPLE;
+	    PL_seen_zerolen++;		/* Do not optimize RE away */
+	    nextchar();
+	    break;
+	case 'w':
+	    ret = reg_node((PL_regflags & PMf_LOCALE) ? ALNUML : ALNUM);
+	    *flagp |= HASWIDTH|SIMPLE;
+	    nextchar();
+	    break;
+	case 'W':
+	    ret = reg_node((PL_regflags & PMf_LOCALE) ? NALNUML : NALNUM);
+	    *flagp |= HASWIDTH|SIMPLE;
+	    nextchar();
+	    break;
+	case 'b':
+	    PL_seen_zerolen++;
+	    ret = reg_node((PL_regflags & PMf_LOCALE) ? BOUNDL : BOUND);
+	    *flagp |= SIMPLE;
+	    nextchar();
+	    break;
+	case 'B':
+	    PL_seen_zerolen++;
+	    ret = reg_node((PL_regflags & PMf_LOCALE) ? NBOUNDL : NBOUND);
+	    *flagp |= SIMPLE;
+	    nextchar();
+	    break;
+	case 's':
+	    ret = reg_node((PL_regflags & PMf_LOCALE) ? SPACEL : SPACE);
+	    *flagp |= HASWIDTH|SIMPLE;
+	    nextchar();
+	    break;
+	case 'S':
+	    ret = reg_node((PL_regflags & PMf_LOCALE) ? NSPACEL : NSPACE);
+	    *flagp |= HASWIDTH|SIMPLE;
+	    nextchar();
+	    break;
+	case 'd':
+	    ret = reg_node(DIGIT);
+	    *flagp |= HASWIDTH|SIMPLE;
+	    nextchar();
+	    break;
+	case 'D':
+	    ret = reg_node(NDIGIT);
+	    *flagp |= HASWIDTH|SIMPLE;
+	    nextchar();
+	    break;
+	case 'n':
+	case 'r':
+	case 't':
+	case 'f':
+	case 'e':
+	case 'a':
+	case 'x':
+	case 'c':
+	case '0':
+	    goto defchar;
+	case '1': case '2': case '3': case '4':
+	case '5': case '6': case '7': case '8': case '9':
+	    {
+		I32 num = atoi(PL_regcomp_parse);
+
+		if (num > 9 && num >= PL_regnpar)
+		    goto defchar;
+		else {
+		    if (!SIZE_ONLY && num > PL_regcomp_rx->nparens)
+			FAIL("reference to nonexistent group");
+		    PL_regsawback = 1;
+		    ret = reganode((PL_regflags & PMf_FOLD)
+				   ? ((PL_regflags & PMf_LOCALE) ? REFFL : REFF)
+				   : REF, num);
+		    *flagp |= HASWIDTH;
+		    while (isDIGIT(*PL_regcomp_parse))
+			PL_regcomp_parse++;
+		    PL_regcomp_parse--;
+		    nextchar();
+		}
+	    }
+	    break;
+	case '\0':
+	    if (PL_regcomp_parse >= PL_regxend)
+		FAIL("trailing \\ in regexp");
+	    /* FALL THROUGH */
+	default:
+	    goto defchar;
+	}
+	break;
+
+    case '#':
+	if (PL_regflags & PMf_EXTENDED) {
+	    while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != '\n') PL_regcomp_parse++;
+	    if (PL_regcomp_parse < PL_regxend)
+		goto tryagain;
+	}
+	/* FALL THROUGH */
+
+    default: {
+	    register I32 len;
+	    register U8 ender;
+	    register char *p;
+	    char *oldp, *s;
+	    I32 numlen;
+
+	    PL_regcomp_parse++;
+
+	defchar:
+	    ret = reg_node((PL_regflags & PMf_FOLD)
+			  ? ((PL_regflags & PMf_LOCALE) ? EXACTFL : EXACTF)
+			  : EXACT);
+	    s = (char *) OPERAND(ret);
+	    regc(0, s++);		/* save spot for len */
+	    for (len = 0, p = PL_regcomp_parse - 1;
+	      len < 127 && p < PL_regxend;
+	      len++)
+	    {
+		oldp = p;
+
+		if (PL_regflags & PMf_EXTENDED)
+		    p = regwhite(p, PL_regxend);
+		switch (*p) {
+		case '^':
+		case '$':
+		case '.':
+		case '[':
+		case '(':
+		case ')':
+		case '|':
+		    goto loopdone;
+		case '\\':
+		    switch (*++p) {
+		    case 'A':
+		    case 'G':
+		    case 'Z':
+		    case 'z':
+		    case 'w':
+		    case 'W':
+		    case 'b':
+		    case 'B':
+		    case 's':
+		    case 'S':
+		    case 'd':
+		    case 'D':
+			--p;
+			goto loopdone;
+		    case 'n':
+			ender = '\n';
+			p++;
+			break;
+		    case 'r':
+			ender = '\r';
+			p++;
+			break;
+		    case 't':
+			ender = '\t';
+			p++;
+			break;
+		    case 'f':
+			ender = '\f';
+			p++;
+			break;
+		    case 'e':
+			ender = '\033';
+			p++;
+			break;
+		    case 'a':
+			ender = '\007';
+			p++;
+			break;
+		    case 'x':
+			ender = scan_hex(++p, 2, &numlen);
+			p += numlen;
+			break;
+		    case 'c':
+			p++;
+			ender = UCHARAT(p++);
+			ender = toCTRL(ender);
+			break;
+		    case '0': case '1': case '2': case '3':case '4':
+		    case '5': case '6': case '7': case '8':case '9':
+			if (*p == '0' ||
+			  (isDIGIT(p[1]) && atoi(p) >= PL_regnpar) ) {
+			    ender = scan_oct(p, 3, &numlen);
+			    p += numlen;
+			}
+			else {
+			    --p;
+			    goto loopdone;
+			}
+			break;
+		    case '\0':
+			if (p >= PL_regxend)
+			    FAIL("trailing \\ in regexp");
+			/* FALL THROUGH */
+		    default:
+			ender = *p++;
+			break;
+		    }
+		    break;
+		default:
+		    ender = *p++;
+		    break;
+		}
+		if (PL_regflags & PMf_EXTENDED)
+		    p = regwhite(p, PL_regxend);
+		if (ISMULT2(p)) { /* Back off on ?+*. */
+		    if (len)
+			p = oldp;
+		    else {
+			len++;
+			regc(ender, s++);
+		    }
+		    break;
+		}
+		regc(ender, s++);
+	    }
+	loopdone:
+	    PL_regcomp_parse = p - 1;
+	    nextchar();
+	    if (len < 0)
+		FAIL("internal disaster in regexp");
+	    if (len > 0)
+		*flagp |= HASWIDTH;
+	    if (len == 1)
+		*flagp |= SIMPLE;
+	    if (!SIZE_ONLY)
+		*OPERAND(ret) = len;
+	    regc('\0', s++);
+	    if (SIZE_ONLY) {
+		PL_regsize += (len + 2 + sizeof(regnode) - 1) / sizeof(regnode);
+	    } else {
+		PL_regcode += (len + 2 + sizeof(regnode) - 1) / sizeof(regnode);
+	    }
+	}
+	break;
+    }
+
+    return(ret);
+}
+
+STATIC char *
+regwhite(char *p, char *e)
+{
+    while (p < e) {
+	if (isSPACE(*p))
+	    ++p;
+	else if (*p == '#') {
+	    do {
+		p++;
+	    } while (p < e && *p != '\n');
+	}
+	else
+	    break;
+    }
+    return p;
+}
+
+STATIC regnode *
+regclass(void)
+{
+    dTHR;
+    register char *opnd, *s;
+    register I32 Class;
+    register I32 lastclass = 1234;
+    register I32 range = 0;
+    register regnode *ret;
+    register I32 def;
+    I32 numlen;
+
+    s = opnd = (char *) OPERAND(PL_regcode);
+    ret = reg_node(ANYOF);
+    for (Class = 0; Class < 33; Class++)
+	regc(0, s++);
+    if (*PL_regcomp_parse == '^') {	/* Complement of range. */
+	PL_regnaughty++;
+	PL_regcomp_parse++;
+	if (!SIZE_ONLY)
+	    *opnd |= ANYOF_INVERT;
+    }
+    if (!SIZE_ONLY) {
+ 	PL_regcode += ANY_SKIP;
+	if (PL_regflags & PMf_FOLD)
+	    *opnd |= ANYOF_FOLD;
+	if (PL_regflags & PMf_LOCALE)
+	    *opnd |= ANYOF_LOCALE;
+    } else {
+	PL_regsize += ANY_SKIP;
+    }
+    if (*PL_regcomp_parse == ']' || *PL_regcomp_parse == '-')
+	goto skipcond;		/* allow 1st char to be ] or - */
+    while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != ']') {
+       skipcond:
+	Class = UCHARAT(PL_regcomp_parse++);
+	if (Class == '[' && PL_regcomp_parse + 1 < PL_regxend &&
+	    /* I smell either [: or [= or [. -- POSIX has been here, right? */
+	    (*PL_regcomp_parse == ':' || *PL_regcomp_parse == '=' || *PL_regcomp_parse == '.')) {
+	    char  posixccc = *PL_regcomp_parse;
+	    char* posixccs = PL_regcomp_parse++;
+	    
+	    while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != posixccc)
+		PL_regcomp_parse++;
+	    if (PL_regcomp_parse == PL_regxend)
+		/* Grandfather lone [:, [=, [. */
+		PL_regcomp_parse = posixccs;
+	    else {
+		PL_regcomp_parse++; /* skip over the posixccc */
+		if (*PL_regcomp_parse == ']') {
+		    /* Not Implemented Yet.
+		     * (POSIX Extended Character Classes, that is)
+		     * The text between e.g. [: and :] would start
+		     * at posixccs + 1 and stop at regcomp_parse - 2. */
+		    if (PL_dowarn && !SIZE_ONLY)
+			warn("Character class syntax [%c %c] is reserved for future extensions", posixccc, posixccc);
+		    PL_regcomp_parse++; /* skip over the ending ] */
+		}
+	    }
+	}
+	if (Class == '\\') {
+	    Class = UCHARAT(PL_regcomp_parse++);
+	    switch (Class) {
+	    case 'w':
+		if (!SIZE_ONLY) {
+		    if (PL_regflags & PMf_LOCALE)
+			*opnd |= ANYOF_ALNUML;
+		    else {
+			for (Class = 0; Class < 256; Class++)
+			    if (isALNUM(Class))
+				ANYOF_SET(opnd, Class);
+		    }
+		}
+		lastclass = 1234;
+		continue;
+	    case 'W':
+		if (!SIZE_ONLY) {
+		    if (PL_regflags & PMf_LOCALE)
+			*opnd |= ANYOF_NALNUML;
+		    else {
+			for (Class = 0; Class < 256; Class++)
+			    if (!isALNUM(Class))
+				ANYOF_SET(opnd, Class);
+		    }
+		}
+		lastclass = 1234;
+		continue;
+	    case 's':
+		if (!SIZE_ONLY) {
+		    if (PL_regflags & PMf_LOCALE)
+			*opnd |= ANYOF_SPACEL;
+		    else {
+			for (Class = 0; Class < 256; Class++)
+			    if (isSPACE(Class))
+				ANYOF_SET(opnd, Class);
+		    }
+		}
+		lastclass = 1234;
+		continue;
+	    case 'S':
+		if (!SIZE_ONLY) {
+		    if (PL_regflags & PMf_LOCALE)
+			*opnd |= ANYOF_NSPACEL;
+		    else {
+			for (Class = 0; Class < 256; Class++)
+			    if (!isSPACE(Class))
+				ANYOF_SET(opnd, Class);
+		    }
+		}
+		lastclass = 1234;
+		continue;
+	    case 'd':
+		if (!SIZE_ONLY) {
+		    for (Class = '0'; Class <= '9'; Class++)
+			ANYOF_SET(opnd, Class);
+		}
+		lastclass = 1234;
+		continue;
+	    case 'D':
+		if (!SIZE_ONLY) {
+		    for (Class = 0; Class < '0'; Class++)
+			ANYOF_SET(opnd, Class);
+		    for (Class = '9' + 1; Class < 256; Class++)
+			ANYOF_SET(opnd, Class);
+		}
+		lastclass = 1234;
+		continue;
+	    case 'n':
+		Class = '\n';
+		break;
+	    case 'r':
+		Class = '\r';
+		break;
+	    case 't':
+		Class = '\t';
+		break;
+	    case 'f':
+		Class = '\f';
+		break;
+	    case 'b':
+		Class = '\b';
+		break;
+	    case 'e':
+		Class = '\033';
+		break;
+	    case 'a':
+		Class = '\007';
+		break;
+	    case 'x':
+		Class = scan_hex(PL_regcomp_parse, 2, &numlen);
+		PL_regcomp_parse += numlen;
+		break;
+	    case 'c':
+		Class = UCHARAT(PL_regcomp_parse++);
+		Class = toCTRL(Class);
+		break;
+	    case '0': case '1': case '2': case '3': case '4':
+	    case '5': case '6': case '7': case '8': case '9':
+		Class = scan_oct(--PL_regcomp_parse, 3, &numlen);
+		PL_regcomp_parse += numlen;
+		break;
+	    }
+	}
+	if (range) {
+	    if (lastclass > Class)
+		FAIL("invalid [] range in regexp");
+	    range = 0;
+	}
+	else {
+	    lastclass = Class;
+	    if (*PL_regcomp_parse == '-' && PL_regcomp_parse+1 < PL_regxend &&
+	      PL_regcomp_parse[1] != ']') {
+		PL_regcomp_parse++;
+		range = 1;
+		continue;	/* do it next time */
+	    }
+	}
+	if (!SIZE_ONLY) {
+	    for ( ; lastclass <= Class; lastclass++)
+		ANYOF_SET(opnd, lastclass);
+	}
+	lastclass = Class;
+    }
+    if (*PL_regcomp_parse != ']')
+	FAIL("unmatched [] in regexp");
+    nextchar();
+    /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
+    if (!SIZE_ONLY && (*opnd & (0xFF ^ ANYOF_INVERT)) == ANYOF_FOLD) {
+	for (Class = 0; Class < 256; ++Class) {
+	    if (ANYOF_TEST(opnd, Class)) {
+		I32 cf = fold[Class];
+		ANYOF_SET(opnd, cf);
+	    }
+	}
+	*opnd &= ~ANYOF_FOLD;
+    }
+    /* optimize inverted simple patterns (e.g. [^a-z]) */
+    if (!SIZE_ONLY && (*opnd & 0xFF) == ANYOF_INVERT) {
+	for (Class = 0; Class < 32; ++Class)
+	    opnd[1 + Class] ^= 0xFF;
+	*opnd = 0;
+    }
+    return ret;
+}
+
+STATIC char*
+nextchar(void)
+{
+    dTHR;
+    char* retval = PL_regcomp_parse++;
+
+    for (;;) {
+	if (*PL_regcomp_parse == '(' && PL_regcomp_parse[1] == '?' &&
+		PL_regcomp_parse[2] == '#') {
+	    while (*PL_regcomp_parse && *PL_regcomp_parse != ')')
+		PL_regcomp_parse++;
+	    PL_regcomp_parse++;
+	    continue;
+	}
+	if (PL_regflags & PMf_EXTENDED) {
+	    if (isSPACE(*PL_regcomp_parse)) {
+		PL_regcomp_parse++;
+		continue;
+	    }
+	    else if (*PL_regcomp_parse == '#') {
+		while (*PL_regcomp_parse && *PL_regcomp_parse != '\n')
+		    PL_regcomp_parse++;
+		PL_regcomp_parse++;
+		continue;
+	    }
+	}
+	return retval;
+    }
+}
+
+/*
+- reg_node - emit a node
+*/
+STATIC regnode *			/* Location. */
+reg_node(U8 op)
+{
+    dTHR;
+    register regnode *ret;
+    register regnode *ptr;
+
+    ret = PL_regcode;
+    if (SIZE_ONLY) {
+	SIZE_ALIGN(PL_regsize);
+	PL_regsize += 1;
+	return(ret);
+    }
+
+    NODE_ALIGN_FILL(ret);
+    ptr = ret;
+    FILL_ADVANCE_NODE(ptr, op);
+    PL_regcode = ptr;
+
+    return(ret);
+}
+
+/*
+- reganode - emit a node with an argument
+*/
+STATIC regnode *			/* Location. */
+reganode(U8 op, U32 arg)
+{
+    dTHR;
+    register regnode *ret;
+    register regnode *ptr;
+
+    ret = PL_regcode;
+    if (SIZE_ONLY) {
+	SIZE_ALIGN(PL_regsize);
+	PL_regsize += 2;
+	return(ret);
+    }
+
+    NODE_ALIGN_FILL(ret);
+    ptr = ret;
+    FILL_ADVANCE_NODE_ARG(ptr, op, arg);
+    PL_regcode = ptr;
+
+    return(ret);
+}
+
+/*
+- regc - emit (if appropriate) a byte of code
+*/
+STATIC void
+regc(U8 b, char* s)
+{
+    dTHR;
+    if (!SIZE_ONLY)
+	*s = b;
+}
+
+/*
+- reginsert - insert an operator in front of already-emitted operand
+*
+* Means relocating the operand.
+*/
+STATIC void
+reginsert(U8 op, regnode *opnd)
+{
+    dTHR;
+    register regnode *src;
+    register regnode *dst;
+    register regnode *place;
+    register int offset = regarglen[(U8)op];
+    
+/* (regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
+
+    if (SIZE_ONLY) {
+	PL_regsize += NODE_STEP_REGNODE + offset;
+	return;
+    }
+
+    src = PL_regcode;
+    PL_regcode += NODE_STEP_REGNODE + offset;
+    dst = PL_regcode;
+    while (src > opnd)
+	StructCopy(--src, --dst, regnode);
+
+    place = opnd;		/* Op node, where operand used to be. */
+    src = NEXTOPER(place);
+    FILL_ADVANCE_NODE(place, op);
+    Zero(src, offset, regnode);
+}
+
+/*
+- regtail - set the next-pointer at the end of a node chain of p to val.
+*/
+STATIC void
+regtail(regnode *p, regnode *val)
+{
+    dTHR;
+    register regnode *scan;
+    register regnode *temp;
+    register I32 offset;
+
+    if (SIZE_ONLY)
+	return;
+
+    /* Find last node. */
+    scan = p;
+    for (;;) {
+	temp = regnext(scan);
+	if (temp == NULL)
+	    break;
+	scan = temp;
+    }
+
+    if (reg_off_by_arg[OP(scan)]) {
+	ARG_SET(scan, val - scan);
+    } else {
+	NEXT_OFF(scan) = val - scan;
+    }
+}
+
+/*
+- regoptail - regtail on operand of first argument; nop if operandless
+*/
+STATIC void
+regoptail(regnode *p, regnode *val)
+{
+    dTHR;
+    /* "Operandless" and "op != BRANCH" are synonymous in practice. */
+    if (p == NULL || SIZE_ONLY)
+	return;
+    if (regkind[(U8)OP(p)] == BRANCH) {
+	regtail(NEXTOPER(p), val);
+    } else if ( regkind[(U8)OP(p)] == BRANCHJ) {
+	regtail(NEXTOPER(NEXTOPER(p)), val);
+    } else
+	return;
+}
+
+/*
+ - regcurly - a little FSA that accepts {\d+,?\d*}
+ */
+STATIC I32
+regcurly(register char *s)
+{
+    if (*s++ != '{')
+	return FALSE;
+    if (!isDIGIT(*s))
+	return FALSE;
+    while (isDIGIT(*s))
+	s++;
+    if (*s == ',')
+	s++;
+    while (isDIGIT(*s))
+	s++;
+    if (*s != '}')
+	return FALSE;
+    return TRUE;
+}
+
+
+STATIC regnode *
+dumpuntil(regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
+{
+#ifdef DEBUGGING
+    register char op = EXACT;	/* Arbitrary non-END op. */
+    register regnode *next, *onode;
+
+    while (op != END && (!last || node < last)) {
+	/* While that wasn't END last time... */
+
+	NODE_ALIGN(node);
+	op = OP(node);
+	if (op == CLOSE)
+	    l--;	
+	next = regnext(node);
+	/* Where, what. */
+	if (OP(node) == OPTIMIZED)
+	    goto after_print;
+	regprop(sv, node);
+	PerlIO_printf(Perl_debug_log, "%4d:%*s%s", node - start, 
+		      2*l + 1, "", SvPVX(sv));
+	if (next == NULL)		/* Next ptr. */
+	    PerlIO_printf(Perl_debug_log, "(0)");
+	else 
+	    PerlIO_printf(Perl_debug_log, "(%d)", next - start);
+	(void)PerlIO_putc(Perl_debug_log, '\n');
+      after_print:
+	if (regkind[(U8)op] == BRANCHJ) {
+	    register regnode *nnode = (OP(next) == LONGJMP 
+				       ? regnext(next) 
+				       : next);
+	    if (last && nnode > last)
+		nnode = last;
+	    node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
+	} else if (regkind[(U8)op] == BRANCH) {
+	    node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
+	} else if ( op == CURLY) {   /* `next' might be very big: optimizer */
+	    node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
+			     NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
+	} else if (regkind[(U8)op] == CURLY && op != CURLYX) {
+	    node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
+			     next, sv, l + 1);
+	} else if ( op == PLUS || op == STAR) {
+	    node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
+	} else if (op == ANYOF) {
+	    node = NEXTOPER(node);
+	    node += ANY_SKIP;
+	} else if (regkind[(U8)op] == EXACT) {
+            /* Literal string, where present. */
+	    node += ((*OPERAND(node)) + 2 + sizeof(regnode) - 1) / sizeof(regnode);
+	    node = NEXTOPER(node);
+	} else {
+	    node = NEXTOPER(node);
+	    node += regarglen[(U8)op];
+	}
+	if (op == CURLYX || op == OPEN)
+	    l++;
+	else if (op == WHILEM)
+	    l--;
+    }
+#endif	/* DEBUGGING */
+    return node;
+}
+
+/*
+ - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
+ */
+void
+regdump(regexp *r)
+{
+#ifdef DEBUGGING
+    dTHR;
+    SV *sv = sv_newmortal();
+
+    (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
+
+    /* Header fields of interest. */
+    if (r->anchored_substr)
+	PerlIO_printf(Perl_debug_log, "anchored `%s%s%s'%s at %d ", 
+		      PL_colors[0],
+		      SvPVX(r->anchored_substr), 
+		      PL_colors[1],
+		      SvTAIL(r->anchored_substr) ? "$" : "",
+		      r->anchored_offset);
+    if (r->float_substr)
+	PerlIO_printf(Perl_debug_log, "floating `%s%s%s'%s at %d..%u ", 
+		      PL_colors[0],
+		      SvPVX(r->float_substr), 
+		      PL_colors[1],
+		      SvTAIL(r->float_substr) ? "$" : "",
+		      r->float_min_offset, r->float_max_offset);
+    if (r->check_substr)
+	PerlIO_printf(Perl_debug_log, 
+		      r->check_substr == r->float_substr 
+		      ? "(checking floating" : "(checking anchored");
+    if (r->reganch & ROPT_NOSCAN)
+	PerlIO_printf(Perl_debug_log, " noscan");
+    if (r->reganch & ROPT_CHECK_ALL)
+	PerlIO_printf(Perl_debug_log, " isall");
+    if (r->check_substr)
+	PerlIO_printf(Perl_debug_log, ") ");
+
+    if (r->regstclass) {
+	regprop(sv, r->regstclass);
+	PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
+    }
+    if (r->reganch & ROPT_ANCH) {
+	PerlIO_printf(Perl_debug_log, "anchored");
+	if (r->reganch & ROPT_ANCH_BOL)
+	    PerlIO_printf(Perl_debug_log, "(BOL)");
+	if (r->reganch & ROPT_ANCH_MBOL)
+	    PerlIO_printf(Perl_debug_log, "(MBOL)");
+	if (r->reganch & ROPT_ANCH_GPOS)
+	    PerlIO_printf(Perl_debug_log, "(GPOS)");
+	PerlIO_putc(Perl_debug_log, ' ');
+    }
+    if (r->reganch & ROPT_GPOS_SEEN)
+	PerlIO_printf(Perl_debug_log, "GPOS ");
+    if (r->reganch & ROPT_SKIP)
+	PerlIO_printf(Perl_debug_log, "plus ");
+    if (r->reganch & ROPT_IMPLICIT)
+	PerlIO_printf(Perl_debug_log, "implicit ");
+    PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
+    if (r->reganch & ROPT_EVAL_SEEN)
+	PerlIO_printf(Perl_debug_log, "with eval ");
+    PerlIO_printf(Perl_debug_log, "\n");
+#endif	/* DEBUGGING */
+}
+
+/*
+- regprop - printable representation of opcode
+*/
+void
+regprop(SV *sv, regnode *o)
+{
+#ifdef DEBUGGING
+    dTHR;
+    register char *p = 0;
+
+    sv_setpvn(sv, "", 0);
+    switch (OP(o)) {
+    case BOL:
+	p = "BOL";
+	break;
+    case MBOL:
+	p = "MBOL";
+	break;
+    case SBOL:
+	p = "SBOL";
+	break;
+    case EOL:
+	p = "EOL";
+	break;
+    case EOS:
+	p = "EOS";
+	break;
+    case MEOL:
+	p = "MEOL";
+	break;
+    case SEOL:
+	p = "SEOL";
+	break;
+    case ANY:
+	p = "ANY";
+	break;
+    case SANY:
+	p = "SANY";
+	break;
+    case ANYOF:
+	p = "ANYOF";
+	break;
+    case BRANCH:
+	p = "BRANCH";
+	break;
+    case EXACT:
+	sv_catpvf(sv, "EXACT <%s%s%s>", PL_colors[0], OPERAND(o) + 1, PL_colors[1]);
+	break;
+    case EXACTF:
+	sv_catpvf(sv, "EXACTF <%s%s%s>", PL_colors[0], OPERAND(o) + 1, PL_colors[1]);
+	break;
+    case EXACTFL:
+	sv_catpvf(sv, "EXACTFL <%s%s%s>", PL_colors[0], OPERAND(o) + 1, PL_colors[1]);
+	break;
+    case NOTHING:
+	p = "NOTHING";
+	break;
+    case TAIL:
+	p = "TAIL";
+	break;
+    case BACK:
+	p = "BACK";
+	break;
+    case END:
+	p = "END";
+	break;
+    case BOUND:
+	p = "BOUND";
+	break;
+    case BOUNDL:
+	p = "BOUNDL";
+	break;
+    case NBOUND:
+	p = "NBOUND";
+	break;
+    case NBOUNDL:
+	p = "NBOUNDL";
+	break;
+    case CURLY:
+	sv_catpvf(sv, "CURLY {%d,%d}", ARG1(o), ARG2(o));
+	break;
+    case CURLYM:
+	sv_catpvf(sv, "CURLYM[%d] {%d,%d}", o->flags, ARG1(o), ARG2(o));
+	break;
+    case CURLYN:
+	sv_catpvf(sv, "CURLYN[%d] {%d,%d}", o->flags, ARG1(o), ARG2(o));
+	break;
+    case CURLYX:
+	sv_catpvf(sv, "CURLYX {%d,%d}", ARG1(o), ARG2(o));
+	break;
+    case REF:
+	sv_catpvf(sv, "REF%d", ARG(o));
+	break;
+    case REFF:
+	sv_catpvf(sv, "REFF%d", ARG(o));
+	break;
+    case REFFL:
+	sv_catpvf(sv, "REFFL%d", ARG(o));
+	break;
+    case OPEN:
+	sv_catpvf(sv, "OPEN%d", ARG(o));
+	break;
+    case CLOSE:
+	sv_catpvf(sv, "CLOSE%d", ARG(o));
+	p = NULL;
+	break;
+    case STAR:
+	p = "STAR";
+	break;
+    case PLUS:
+	p = "PLUS";
+	break;
+    case MINMOD:
+	p = "MINMOD";
+	break;
+    case GPOS:
+	p = "GPOS";
+	break;
+    case UNLESSM:
+	sv_catpvf(sv, "UNLESSM[-%d]", o->flags);
+	break;
+    case IFMATCH:
+	sv_catpvf(sv, "IFMATCH[-%d]", o->flags);
+	break;
+    case SUCCEED:
+	p = "SUCCEED";
+	break;
+    case WHILEM:
+	p = "WHILEM";
+	break;
+    case DIGIT:
+	p = "DIGIT";
+	break;
+    case NDIGIT:
+	p = "NDIGIT";
+	break;
+    case ALNUM:
+	p = "ALNUM";
+	break;
+    case NALNUM:
+	p = "NALNUM";
+	break;
+    case SPACE:
+	p = "SPACE";
+	break;
+    case NSPACE:
+	p = "NSPACE";
+	break;
+    case ALNUML:
+	p = "ALNUML";
+	break;
+    case NALNUML:
+	p = "NALNUML";
+	break;
+    case SPACEL:
+	p = "SPACEL";
+	break;
+    case NSPACEL:
+	p = "NSPACEL";
+	break;
+    case EVAL:
+	p = "EVAL";
+	break;
+    case LONGJMP:
+	p = "LONGJMP";
+	break;
+    case BRANCHJ:
+	p = "BRANCHJ";
+	break;
+    case IFTHEN:
+	p = "IFTHEN";
+	break;
+    case GROUPP:
+	sv_catpvf(sv, "GROUPP%d", ARG(o));
+	break;
+    case LOGICAL:
+	p = "LOGICAL";
+	break;
+    case SUSPEND:
+	p = "SUSPEND";
+	break;
+    case RENUM:
+	p = "RENUM";
+	break;
+    case OPTIMIZED:
+	p = "OPTIMIZED";
+	break;
+    default:
+	FAIL("corrupted regexp opcode");
+    }
+    if (p)
+	sv_catpv(sv, p);
+#endif	/* DEBUGGING */
+}
+
+void
+pregfree(struct regexp *r)
+{
+    dTHR;
+    if (!r || (--r->refcnt > 0))
+	return;
+    if (r->precomp)
+	Safefree(r->precomp);
+    if (r->subbase)
+	Safefree(r->subbase);
+    if (r->substrs) {
+	if (r->anchored_substr)
+	    SvREFCNT_dec(r->anchored_substr);
+	if (r->float_substr)
+	    SvREFCNT_dec(r->float_substr);
+	Safefree(r->substrs);
+    }
+    if (r->data) {
+	int n = r->data->count;
+	while (--n >= 0) {
+	    switch (r->data->what[n]) {
+	    case 's':
+		SvREFCNT_dec((SV*)r->data->data[n]);
+		break;
+	    case 'o':
+		op_free((OP_4tree*)r->data->data[n]);
+		break;
+	    case 'n':
+		break;
+	    default:
+		FAIL2("panic: regfree data code '%c'", r->data->what[n]);
+	    }
+	}
+	Safefree(r->data->what);
+	Safefree(r->data);
+    }
+    Safefree(r->startp);
+    Safefree(r->endp);
+    Safefree(r);
+}
+
+/*
+ - regnext - dig the "next" pointer out of a node
+ *
+ * [Note, when REGALIGN is defined there are two places in regmatch()
+ * that bypass this code for speed.]
+ */
+regnode *
+regnext(register regnode *p)
+{
+    dTHR;
+    register I32 offset;
+
+    if (p == &PL_regdummy)
+	return(NULL);
+
+    offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
+    if (offset == 0)
+	return(NULL);
+
+    return(p+offset);
+}
+
+STATIC void	
+re_croak2(const char* pat1,const char* pat2,...)
+{
+    va_list args;
+    STRLEN l1 = strlen(pat1);
+    STRLEN l2 = strlen(pat2);
+    char buf[512];
+    char *message;
+
+    if (l1 > 510)
+	l1 = 510;
+    if (l1 + l2 > 510)
+	l2 = 510 - l1;
+    Copy(pat1, buf, l1 , char);
+    Copy(pat2, buf + l1, l2 , char);
+    buf[l1 + l2] = '\n';
+    buf[l1 + l2 + 1] = '\0';
+    va_start(args, pat2);
+    message = mess(buf, &args);
+    va_end(args);
+    l1 = strlen(message);
+    if (l1 > 512)
+	l1 = 512;
+    Copy(message, buf, l1 , char);
+    buf[l1] = '\0';			/* Overwrite \n */
+    croak("%s", buf);
+}