This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Remove set magic from typeglobs. Remove typeglob magic entirely.
[perl5.git] / regexec.c
index 17ee6af..919a12b 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -55,7 +55,6 @@
 #  define PERL_NO_GET_CONTEXT
 #endif
 
-/*SUPPRESS 112*/
 /*
  * pregcomp and pregexec -- regsub and regerror are not used in perl
  *
@@ -79,7 +78,7 @@
  ****    Alterations to Henry's code are...
  ****
  ****    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- ****    2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
+ ****    2000, 2001, 2002, 2003, 2004, 2005, 2006, by Larry Wall and others
  ****
  ****    You may distribute under the terms of either the GNU General Public
  ****    License or the Artistic License, as specified in the README file.
 #define HOP3c(pos,off,lim) ((char*)HOP3(pos,off,lim))
 #define HOPMAYBE3c(pos,off,lim) ((char*)HOPMAYBE3(pos,off,lim))
 
-#define LOAD_UTF8_CHARCLASS(a,b) STMT_START { if (!CAT2(PL_utf8_,a)) { ENTER; save_re_context(); (void)CAT2(is_utf8_, a)((const U8*)b); LEAVE; } } STMT_END
+#define LOAD_UTF8_CHARCLASS(class,str) STMT_START { \
+    if (!CAT2(PL_utf8_,class)) { bool ok; ENTER; save_re_context(); ok=CAT2(is_utf8_,class)((const U8*)str); assert(ok); LEAVE; } } STMT_END
+#define LOAD_UTF8_CHARCLASS_ALNUM() LOAD_UTF8_CHARCLASS(alnum,"a")
+#define LOAD_UTF8_CHARCLASS_DIGIT() LOAD_UTF8_CHARCLASS(digit,"0")
+#define LOAD_UTF8_CHARCLASS_SPACE() LOAD_UTF8_CHARCLASS(space," ")
+#define LOAD_UTF8_CHARCLASS_MARK()  LOAD_UTF8_CHARCLASS(mark, "\xcd\x86")
 
 /* for use after a quantifier and before an EXACT-like node -- japhy */
 #define JUMPABLE(rn) ( \
@@ -174,9 +178,10 @@ static void restore_pos(pTHX_ void *arg);
 STATIC CHECKPOINT
 S_regcppush(pTHX_ I32 parenfloor)
 {
-    int retval = PL_savestack_ix;
+    dVAR;
+    const int retval = PL_savestack_ix;
 #define REGCP_PAREN_ELEMS 4
-    int paren_elems_to_push = (PL_regsize - parenfloor) * REGCP_PAREN_ELEMS;
+    const int paren_elems_to_push = (PL_regsize - parenfloor) * REGCP_PAREN_ELEMS;
     int p;
 
     if (paren_elems_to_push < 0)
@@ -218,10 +223,10 @@ S_regcppush(pTHX_ I32 parenfloor)
 STATIC char *
 S_regcppop(pTHX)
 {
+    dVAR;
     I32 i;
     U32 paren = 0;
     char *input;
-    I32 tmps;
 
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -237,6 +242,7 @@ S_regcppop(pTHX)
     /* Now restore the parentheses context. */
     for (i -= (REGCP_OTHER_ELEMS - REGCP_FRAME_ELEMS);
         i > 0; i -= REGCP_PAREN_ELEMS) {
+       I32 tmps;
        paren = (U32)SSPOPINT;
        PL_reg_start_tmp[paren] = (char *) SSPOPPTR;
        PL_regstartp[paren] = SSPOPINT;
@@ -279,17 +285,6 @@ S_regcppop(pTHX)
     return input;
 }
 
-STATIC char *
-S_regcp_set_to(pTHX_ I32 ss)
-{
-    I32 tmp = PL_savestack_ix;
-
-    PL_savestack_ix = ss;
-    regcppop();
-    PL_savestack_ix = tmp;
-    return Nullch;
-}
-
 typedef struct re_cc_state
 {
     I32 ss;
@@ -340,6 +335,7 @@ Perl_pregexec(pTHX_ register regexp *prog, char *stringarg, register char *stren
 STATIC void
 S_cache_re(pTHX_ regexp *prog)
 {
+    dVAR;
     PL_regprecomp = prog->precomp;             /* Needed for FAIL. */
 #ifdef DEBUGGING
     PL_regprogram = prog->program;
@@ -365,7 +361,7 @@ S_cache_re(pTHX_ regexp *prog)
 
 /* Assumptions: if ANCH_GPOS, then strpos is anchored. XXXX Check GPOS logic */
 
-/* If SCREAM, then SvPVX(sv) should be compatible with strpos and strend.
+/* If SCREAM, then SvPVX_const(sv) should be compatible with strpos and strend.
    Otherwise, only SvCUR(sv) is used to get strbeg. */
 
 /* XXXX We assume that strpos is strbeg unless sv. */
@@ -399,6 +395,7 @@ char *
 Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                     char *strend, U32 flags, re_scream_pos_data *data)
 {
+    dVAR;
     register I32 start_shift = 0;
     /* Should be nonnegative! */
     register I32 end_shift   = 0;
@@ -406,14 +403,14 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     register SV *check;
     char *strbeg;
     char *t;
-    int do_utf8 = sv ? SvUTF8(sv) : 0; /* if no sv we have to assume bytes */
+    const int do_utf8 = sv ? SvUTF8(sv) : 0;   /* if no sv we have to assume bytes */
     I32 ml_anch;
-    register char *other_last = Nullch;        /* other substr checked before this */
-    char *check_at = Nullch;           /* check substr found at this pos */
-    I32 multiline = prog->reganch & PMf_MULTILINE;
+    register char *other_last = NULL;  /* other substr checked before this */
+    char *check_at = NULL;             /* check substr found at this pos */
+    const I32 multiline = prog->reganch & PMf_MULTILINE;
 #ifdef DEBUGGING
-    char *i_strpos = strpos;
-    SV *dsv = PERL_DEBUG_PAD_ZERO(0);
+    const char * const i_strpos = strpos;
+    SV * const dsv = PERL_DEBUG_PAD_ZERO(0);
 #endif
 
     GET_RE_DEBUG_FLAGS_DECL;
@@ -427,10 +424,10 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     }
 
     DEBUG_EXECUTE_r({
-        char *s   = PL_reg_match_utf8 ?
+        const char *s   = PL_reg_match_utf8 ?
                         sv_uni_display(dsv, sv, 60, UNI_DISPLAY_REGEX) :
                         strpos;
-        int   len = PL_reg_match_utf8 ?
+        const int   len = PL_reg_match_utf8 ?
                         strlen(s) : strend - strpos;
         if (!PL_colorset)
              reginitcolors();
@@ -438,7 +435,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
             DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
                                   "UTF-8 target...\n"));
         PerlIO_printf(Perl_debug_log,
-                      "%sGuessing start of match, REx%s `%s%.60s%s%s' against `%s%.*s%s%s'...\n",
+                      "%sGuessing start of match, REx%s \"%s%.60s%s%s\" against \"%s%.*s%s%s\"...\n",
                       PL_colors[4], PL_colors[5], PL_colors[0],
                       prog->precomp,
                       PL_colors[1],
@@ -480,7 +477,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        if (!ml_anch) {
          if ( !(prog->reganch & (ROPT_ANCH_GPOS /* Checked by the caller */
                                  | ROPT_IMPLICIT)) /* not a real BOL */
-              /* SvCUR is not set on references: SvRV and SvPVX overlap */
+              /* SvCUR is not set on references: SvRV and SvPVX_const overlap */
               && sv && !SvROK(sv)
               && (strpos != strbeg)) {
              DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Not at start...\n"));
@@ -502,18 +499,19 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                }
                /* Now should match s[0..slen-2] */
                slen--;
-               if (slen && (*SvPVX(check) != *s
+               if (slen && (*SvPVX_const(check) != *s
                             || (slen > 1
-                                && memNE(SvPVX(check), s, slen)))) {
+                                && memNE(SvPVX_const(check), s, slen)))) {
                  report_neq:
                    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "String not equal...\n"));
                    goto fail_finish;
                }
            }
-           else if (*SvPVX(check) != *s
+           else if (*SvPVX_const(check) != *s
                     || ((slen = SvCUR(check)) > 1
-                        && memNE(SvPVX(check), s, slen)))
+                        && memNE(SvPVX_const(check), s, slen)))
                goto report_neq;
+           check_at = s;
            goto success_at_start;
          }
        }
@@ -523,9 +521,9 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        end_shift = prog->minlen - start_shift -
            CHR_SVLEN(check) + (SvTAIL(check) != 0);
        if (!ml_anch) {
-           I32 end = prog->check_offset_max + CHR_SVLEN(check)
+           const I32 end = prog->check_offset_max + CHR_SVLEN(check)
                                         - (SvTAIL(check) != 0);
-           I32 eshift = CHR_DIST((U8*)strend, (U8*)s) - end;
+           const I32 eshift = CHR_DIST((U8*)strend, (U8*)s) - end;
 
            if (end_shift < eshift)
                end_shift = eshift;
@@ -550,7 +548,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        the "check" substring in the region corrected by start/end_shift. */
     if (flags & REXEC_SCREAM) {
        I32 p = -1;                     /* Internal iterator of scream. */
-       I32 *pp = data ? data->scream_pos : &p;
+       I32 * const pp = data ? data->scream_pos : &p;
 
        if (PL_screamfirst[BmRARE(check)] >= 0
            || ( BmRARE(check) == '\n'
@@ -562,7 +560,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            goto fail_finish;
        /* we may be pointing at the wrong string */
        if (s && RX_MATCH_COPIED(prog))
-           s = strbeg + (s - SvPVX(sv));
+           s = strbeg + (s - SvPVX_const(sv));
        if (data)
            *data->scream_olds = s;
     }
@@ -578,12 +576,12 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     /* Update the count-of-usability, remove useless subpatterns,
        unshift s.  */
 
-    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s %s substr `%s%.*s%s'%s%s",
+    DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s %s substr \"%s%.*s%s\"%s%s",
                          (s ? "Found" : "Did not find"),
                          (check == (do_utf8 ? prog->anchored_utf8 : prog->anchored_substr) ? "anchored" : "floating"),
                          PL_colors[0],
                          (int)(SvCUR(check) - (SvTAIL(check)!=0)),
-                         SvPVX(check),
+                         SvPVX_const(check),
                          PL_colors[1], (SvTAIL(check) ? "$" : ""),
                          (s ? " at offset " : "...\n") ) );
 
@@ -598,7 +596,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
     /* Got a candidate.  Check MBOL anchoring, and the *other* substr.
        Start with the other substr.
        XXXX no SCREAM optimization yet - and a very coarse implementation
-       XXXX /ttx+/ results in anchored=`ttx', floating=`x'.  floating will
+       XXXX /ttx+/ results in anchored="ttx", floating="x".  floating will
                *always* match.  Probably should be marked during compile...
        Probably it is right to do no SCREAM here...
      */
@@ -611,7 +609,8 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        if (check == (do_utf8 ? prog->float_utf8 : prog->float_substr)) {
          do_other_anchored:
            {
-               char *last = HOP3c(s, -start_shift, strbeg), *last1, *last2;
+               char * const last = HOP3c(s, -start_shift, strbeg);
+               char *last1, *last2;
                char *s1 = s;
                SV* must;
 
@@ -645,12 +644,12 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                        multiline ? FBMrf_MULTILINE : 0
                    );
                DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
-                       "%s anchored substr `%s%.*s%s'%s",
+                       "%s anchored substr \"%s%.*s%s\"%s",
                        (s ? "Found" : "Contradicts"),
                        PL_colors[0],
                          (int)(SvCUR(must)
                          - (SvTAIL(must)!=0)),
-                         SvPVX(must),
+                         SvPVX_const(must),
                          PL_colors[1], (SvTAIL(must) ? "$" : "")));
                if (!s) {
                    if (last1 >= last2) {
@@ -704,11 +703,11 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
                              (unsigned char*)last + SvCUR(must)
                                  - (SvTAIL(must)!=0),
                              must, multiline ? FBMrf_MULTILINE : 0);
-           DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s floating substr `%s%.*s%s'%s",
+           DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s floating substr \"%s%.*s%s\"%s",
                    (s ? "Found" : "Contradicts"),
                    PL_colors[0],
                      (int)(SvCUR(must) - (SvTAIL(must)!=0)),
-                     SvPVX(must),
+                     SvPVX_const(must),
                      PL_colors[1], (SvTAIL(must) ? "$" : "")));
            if (!s) {
                if (last1 == last) {
@@ -833,9 +832,9 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
            SvREFCNT_dec(do_utf8 ? prog->check_utf8 : prog->check_substr);
            if (do_utf8 ? prog->check_substr : prog->check_utf8)
                SvREFCNT_dec(do_utf8 ? prog->check_substr : prog->check_utf8);
-           prog->check_substr = prog->check_utf8 = Nullsv;     /* disable */
-           prog->float_substr = prog->float_utf8 = Nullsv;     /* clear */
-           check = Nullsv;                     /* abort */
+           prog->check_substr = prog->check_utf8 = NULL;       /* disable */
+           prog->float_substr = prog->float_utf8 = NULL;       /* clear */
+           check = NULL;                       /* abort */
            s = strpos;
            /* XXXX This is a remnant of the old implementation.  It
                    looks wasteful, since now INTUIT can use many
@@ -857,11 +856,11 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
           regstclass does not come from lookahead...  */
        /* If regstclass takes bytelength more than 1: If charlength==1, OK.
           This leaves EXACTF only, which is dealt with in find_byclass().  */
-        const U8* str = (U8*)STRING(prog->regstclass);
+        const U8* const str = (U8*)STRING(prog->regstclass);
         const int cl_l = (PL_regkind[(U8)OP(prog->regstclass)] == EXACT
                    ? CHR_DIST(str+STR_LEN(prog->regstclass), str)
                    : 1);
-       char *endpos = (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
+       const char * const endpos = (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
                ? HOP3c(s, (prog->minlen ? cl_l : 0), strend)
                : (prog->float_substr || prog->float_utf8
                   ? HOP3c(HOP3c(check_at, -start_shift, strbeg),
@@ -873,7 +872,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
         s = find_byclass(prog, prog->regstclass, s, endpos, 1);
        if (!s) {
 #ifdef DEBUGGING
-           const char *what = 0;
+           const char *what = NULL;
 #endif
            if (endpos == strend) {
                DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
@@ -958,14 +957,15 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
   fail:
     DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch rejected by optimizer%s\n",
                          PL_colors[4], PL_colors[5]));
-    return Nullch;
+    return NULL;
 }
 
 /* We know what class REx starts with.  Try to find this position... */
 STATIC char *
-S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun)
+S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, const char *strend, I32 norun)
 {
-       I32 doevery = (prog->reganch & ROPT_SKIP) == 0;
+       dVAR;
+       const I32 doevery = (prog->reganch & ROPT_SKIP) == 0;
        char *m;
        STRLEN ln;
        STRLEN lnc;
@@ -974,7 +974,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
        unsigned int c2;
        char *e;
        register I32 tmp = 1;   /* Scratch variable? */
-       register bool do_utf8 = PL_reg_match_utf8;
+       register const bool do_utf8 = PL_reg_match_utf8;
 
        /* We know what class it must start with. */
        switch (OP(c)) {
@@ -1033,14 +1033,15 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
                U8 *sm = (U8 *) m;
                U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
                U8 tmpbuf2[UTF8_MAXBYTES_CASE+1];
+               const U32 uniflags = ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY;
 
                to_utf8_lower((U8*)m, tmpbuf1, &ulen1);
                to_utf8_upper((U8*)m, tmpbuf2, &ulen2);
 
                c1 = utf8n_to_uvchr(tmpbuf1, UTF8_MAXBYTES_CASE, 
-                                   0, ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY);
+                                   0, uniflags);
                c2 = utf8n_to_uvchr(tmpbuf2, UTF8_MAXBYTES_CASE,
-                                   0, ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY);
+                                   0, uniflags);
                lnc = 0;
                while (sm < ((U8 *) m + ln)) {
                    lnc++;
@@ -1078,16 +1079,14 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            if (do_utf8) {
                UV c, f;
                U8 tmpbuf [UTF8_MAXBYTES+1];
-               U8 foldbuf[UTF8_MAXBYTES_CASE+1];
                STRLEN len, foldlen;
-               
+               const U32 uniflags = ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY;
                if (c1 == c2) {
                    /* Upper and lower of 1st char are equal -
                     * probably not a "letter". */
                    while (s <= e) {
                        c = utf8n_to_uvchr((U8*)s, UTF8_MAXBYTES, &len,
-                                          ckWARN(WARN_UTF8) ?
-                                          0 : UTF8_ALLOW_ANY);
+                                          uniflags);
                        if ( c == c1
                             && (ln == len ||
                                 ibcmp_utf8(s, (char **)0, 0,  do_utf8,
@@ -1095,6 +1094,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
                             && (norun || regtry(prog, s)) )
                            goto got_it;
                        else {
+                            U8 foldbuf[UTF8_MAXBYTES_CASE+1];
                             uvchr_to_utf8(tmpbuf, c);
                             f = to_utf8_fold(tmpbuf, foldbuf, &foldlen);
                             if ( f != c
@@ -1113,8 +1113,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
                else {
                    while (s <= e) {
                      c = utf8n_to_uvchr((U8*)s, UTF8_MAXBYTES, &len,
-                                          ckWARN(WARN_UTF8) ?
-                                          0 : UTF8_ALLOW_ANY);
+                                          uniflags);
 
                        /* Handle some of the three Greek sigmas cases.
                         * Note that not all the possible combinations
@@ -1134,6 +1133,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
                             && (norun || regtry(prog, s)) )
                            goto got_it;
                        else {
+                            U8 foldbuf[UTF8_MAXBYTES_CASE+1];
                             uvchr_to_utf8(tmpbuf, c);
                             f = to_utf8_fold(tmpbuf, foldbuf, &foldlen);
                             if ( f != c
@@ -1181,13 +1181,12 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
                if (s == PL_bostr)
                    tmp = '\n';
                else {
-                   U8 *r = reghop3((U8*)s, -1, (U8*)PL_bostr);
-               
+                   U8 * const r = reghop3((U8*)s, -1, (U8*)PL_bostr);
                    tmp = utf8n_to_uvchr(r, UTF8SKIP(r), 0, 0);
                }
                tmp = ((OP(c) == BOUND ?
                        isALNUM_uni(tmp) : isALNUM_LC_uvchr(UNI_TO_NATIVE(tmp))) != 0);
-               LOAD_UTF8_CHARCLASS(alnum,"a");
+               LOAD_UTF8_CHARCLASS_ALNUM();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (tmp == !(OP(c) == BOUND ?
                                 swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8) :
@@ -1224,13 +1223,12 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
                if (s == PL_bostr)
                    tmp = '\n';
                else {
-                   U8 *r = reghop3((U8*)s, -1, (U8*)PL_bostr);
-               
+                   U8 * const r = reghop3((U8*)s, -1, (U8*)PL_bostr);
                    tmp = utf8n_to_uvchr(r, UTF8SKIP(r), 0, 0);
                }
                tmp = ((OP(c) == NBOUND ?
                        isALNUM_uni(tmp) : isALNUM_LC_uvchr(UNI_TO_NATIVE(tmp))) != 0);
-               LOAD_UTF8_CHARCLASS(alnum,"a");
+               LOAD_UTF8_CHARCLASS_ALNUM();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (tmp == !(OP(c) == NBOUND ?
                                 swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8) :
@@ -1259,7 +1257,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            break;
        case ALNUM:
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(alnum,"a");
+               LOAD_UTF8_CHARCLASS_ALNUM();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8)) {
                        if (tmp && (norun || regtry(prog, s)))
@@ -1317,7 +1315,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            break;
        case NALNUM:
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(alnum,"a");
+               LOAD_UTF8_CHARCLASS_ALNUM();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (!swash_fetch(PL_utf8_alnum, (U8*)s, do_utf8)) {
                        if (tmp && (norun || regtry(prog, s)))
@@ -1375,7 +1373,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            break;
        case SPACE:
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(space," ");
+               LOAD_UTF8_CHARCLASS_SPACE();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, do_utf8)) {
                        if (tmp && (norun || regtry(prog, s)))
@@ -1433,7 +1431,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            break;
        case NSPACE:
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(space," ");
+               LOAD_UTF8_CHARCLASS_SPACE();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (!(*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, do_utf8))) {
                        if (tmp && (norun || regtry(prog, s)))
@@ -1491,7 +1489,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            break;
        case DIGIT:
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(digit,"0");
+               LOAD_UTF8_CHARCLASS_DIGIT();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (swash_fetch(PL_utf8_digit,(U8*)s, do_utf8)) {
                        if (tmp && (norun || regtry(prog, s)))
@@ -1549,7 +1547,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, I32 norun
            break;
        case NDIGIT:
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(digit,"0");
+               LOAD_UTF8_CHARCLASS_DIGIT();
                while (s + (uskip = UTF8SKIP(s)) <= strend) {
                    if (!swash_fetch(PL_utf8_digit,(U8*)s, do_utf8)) {
                        if (tmp && (norun || regtry(prog, s)))
@@ -1626,26 +1624,26 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 /* data: May be used for some additional optimizations. */
 /* nosave: For optimizations. */
 {
+    dVAR;
     register char *s;
     register regnode *c;
     register char *startpos = stringarg;
     I32 minlen;                /* must match at least this many chars */
     I32 dontbother = 0;        /* how many characters not to try at end */
-    /* I32 start_shift = 0; */         /* Offset of the start to find
-                                        constant substr. */            /* CC */
     I32 end_shift = 0;                 /* Same for the end. */         /* CC */
     I32 scream_pos = -1;               /* Internal iterator of scream. */
     char *scream_olds;
     SV* oreplsv = GvSV(PL_replgv);
-    bool do_utf8 = DO_UTF8(sv);
-    I32 multiline = prog->reganch & PMf_MULTILINE;
+    const bool do_utf8 = DO_UTF8(sv);
+    const I32 multiline = prog->reganch & PMf_MULTILINE;
 #ifdef DEBUGGING
-    SV *dsv0 = PERL_DEBUG_PAD_ZERO(0);
-    SV *dsv1 = PERL_DEBUG_PAD_ZERO(1);
+    SV * const dsv0 = PERL_DEBUG_PAD_ZERO(0);
+    SV * const dsv1 = PERL_DEBUG_PAD_ZERO(1);
 #endif
 
     GET_RE_DEBUG_FLAGS_DECL;
 
+    PERL_UNUSED_ARG(data);
     RX_MATCH_UTF8_set(prog,do_utf8);
 
     PL_regcc = 0;
@@ -1717,7 +1715,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
            PL_reg_ganch = strbeg;
     }
 
-    if (!(flags & REXEC_CHECKED) && (prog->check_substr != Nullsv || prog->check_utf8 != Nullsv)) {
+    if (!(flags & REXEC_CHECKED) && (prog->check_substr != NULL || prog->check_utf8 != NULL)) {
        re_scream_pos_data d;
 
        d.scream_olds = &scream_olds;
@@ -1730,18 +1728,18 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     }
 
     DEBUG_EXECUTE_r({
-        char *s0   = UTF ?
-          pv_uni_display(dsv0, (U8*)prog->precomp, prog->prelen, 60,
-                         UNI_DISPLAY_REGEX) :
-          prog->precomp;
-        int   len0 = UTF ? SvCUR(dsv0) : prog->prelen;
-        char *s1   = do_utf8 ? sv_uni_display(dsv1, sv, 60,
+       const char * const s0   = UTF
+           ? pv_uni_display(dsv0, (U8*)prog->precomp, prog->prelen, 60,
+                         UNI_DISPLAY_REGEX)
+           : prog->precomp;
+       const int len0 = UTF ? SvCUR(dsv0) : prog->prelen;
+       const char * const s1 = do_utf8 ? sv_uni_display(dsv1, sv, 60,
                                               UNI_DISPLAY_REGEX) : startpos;
-        int   len1 = do_utf8 ? SvCUR(dsv1) : strend - startpos;
+       const int len1 = do_utf8 ? SvCUR(dsv1) : strend - startpos;
         if (!PL_colorset)
             reginitcolors();
         PerlIO_printf(Perl_debug_log,
-                      "%sMatching REx%s `%s%*.*s%s%s' against `%s%.*s%s%s'\n",
+                      "%sMatching REx%s \"%s%*.*s%s%s\" against \"%s%.*s%s%s\"\n",
                       PL_colors[4], PL_colors[5], PL_colors[0],
                       len0, len0, s0,
                       PL_colors[1],
@@ -1812,7 +1810,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 #endif
        if (!(do_utf8 ? prog->anchored_utf8 : prog->anchored_substr))
            do_utf8 ? to_utf8_substr(prog) : to_byte_substr(prog);
-       ch = SvPVX(do_utf8 ? prog->anchored_utf8 : prog->anchored_substr)[0];
+       ch = SvPVX_const(do_utf8 ? prog->anchored_utf8 : prog->anchored_substr)[0];
 
        if (do_utf8) {
            while (s < strend) {
@@ -1843,10 +1841,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                                   "Did not find anchored character...\n")
                );
     }
-    /*SUPPRESS 560*/
-    else if (prog->anchored_substr != Nullsv
-             || prog->anchored_utf8 != Nullsv
-             || ((prog->float_substr != Nullsv || prog->float_utf8 != Nullsv)
+    else if (prog->anchored_substr != NULL
+             || prog->anchored_utf8 != NULL
+             || ((prog->float_substr != NULL || prog->float_utf8 != NULL)
                  && prog->float_max_offset < strend - s)) {
        SV *must;
        I32 back_max;
@@ -1881,7 +1878,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        else
            last1 = s - 1;      /* bogus */
 
-       /* XXXX check_substr already used to find `s', can optimize if
+       /* XXXX check_substr already used to find "s", can optimize if
           check_substr==must. */
        scream_pos = -1;
        dontbother = end_shift;
@@ -1895,7 +1892,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                                  multiline ? FBMrf_MULTILINE : 0))) ) {
            /* we may be pointing at the wrong string */
            if ((flags & REXEC_SCREAM) && RX_MATCH_COPIED(prog))
-               s = strbeg + (s - SvPVX(sv));
+               s = strbeg + (s - SvPVX_const(sv));
            DEBUG_EXECUTE_r( did_match = 1 );
            if (HOPc(s, -back_max) > last1) {
                last1 = HOPc(s, -back_min);
@@ -1924,12 +1921,12 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        }
        DEBUG_EXECUTE_r(if (!did_match)
                     PerlIO_printf(Perl_debug_log, 
-                                  "Did not find %s substr `%s%.*s%s'%s...\n",
+                                  "Did not find %s substr \"%s%.*s%s\"%s...\n",
                              ((must == prog->anchored_substr || must == prog->anchored_utf8)
                               ? "anchored" : "floating"),
                              PL_colors[0],
                              (int)(SvCUR(must) - (SvTAIL(must)!=0)),
-                             SvPVX(must),
+                             SvPVX_const(must),
                                   PL_colors[1], (SvTAIL(must) ? "$" : ""))
                );
        goto phooey;
@@ -1943,22 +1940,22 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
        }
        DEBUG_EXECUTE_r({
            SV *prop = sv_newmortal();
-           char *s0;
-           char *s1;
+           const char *s0;
+           const char *s1;
            int len0;
            int len1;
 
            regprop(prop, c);
            s0 = UTF ?
-             pv_uni_display(dsv0, (U8*)SvPVX(prop), SvCUR(prop), 60,
+             pv_uni_display(dsv0, (U8*)SvPVX_const(prop), SvCUR(prop), 60,
                             UNI_DISPLAY_REGEX) :
-             SvPVX(prop);
+             SvPVX_const(prop);
            len0 = UTF ? SvCUR(dsv0) : SvCUR(prop);
            s1 = UTF ?
              sv_uni_display(dsv1, sv, 60, UNI_DISPLAY_REGEX) : s;
            len1 = UTF ? SvCUR(dsv1) : strend - s;
            PerlIO_printf(Perl_debug_log,
-                         "Matching stclass `%*.*s' against `%*.*s'\n",
+                         "Matching stclass \"%*.*s\" against \"%*.*s\"\n",
                          len0, len0, s0,
                          len1, len1, s1);
        });
@@ -1968,7 +1965,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     }
     else {
        dontbother = 0;
-       if (prog->float_substr != Nullsv || prog->float_utf8 != Nullsv) {
+       if (prog->float_substr != NULL || prog->float_utf8 != NULL) {
            /* Trim the end. */
            char *last;
            SV* float_real;
@@ -1984,18 +1981,18 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                    last = scream_olds; /* Only one occurrence. */
                /* we may be pointing at the wrong string */
                else if (RX_MATCH_COPIED(prog))
-                   s = strbeg + (s - SvPVX(sv));
+                   s = strbeg + (s - SvPVX_const(sv));
            }
            else {
                STRLEN len;
-                const char * const little = SvPV(float_real, len);
+                const char * const little = SvPV_const(float_real, len);
 
                if (SvTAIL(float_real)) {
                    if (memEQ(strend - len + 1, little, len - 1))
                        last = strend - len + 1;
                    else if (!multiline)
                        last = memEQ(strend - len, little, len)
-                           ? strend - len : Nullch;
+                           ? strend - len : NULL;
                    else
                        goto find_last;
                } else {
@@ -2003,7 +2000,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
                    if (len)
                        last = rninstr(s, strend, little, little + len);
                    else
-                       last = strend;  /* matching `$' */
+                       last = strend;  /* matching "$" */
                }
            }
            if (last == NULL) {
@@ -2055,7 +2052,7 @@ got_it:
        RX_MATCH_COPY_FREE(prog);
        if (flags & REXEC_COPY_STR) {
            I32 i = PL_regeol - startpos + (stringarg - strbeg);
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
            if ((SvIsCOW(sv)
                 || (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS)) {
                if (DEBUG_C_TEST) {
@@ -2064,7 +2061,7 @@ got_it:
                                  (int) SvTYPE(sv));
                }
                prog->saved_copy = sv_setsv_cow(prog->saved_copy, sv);
-               prog->subbeg = SvPVX(prog->saved_copy);
+               prog->subbeg = (char *)SvPVX_const(prog->saved_copy);
                assert (SvPOKp(prog->saved_copy));
            } else
 #endif
@@ -2097,6 +2094,7 @@ phooey:
 STATIC I32                     /* 0 failure, 1 success */
 S_regtry(pTHX_ regexp *prog, char *startpos)
 {
+    dVAR;
     register I32 i;
     register I32 *sp;
     register I32 *ep;
@@ -2133,7 +2131,7 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
                  && (mg = mg_find(PL_reg_sv, PERL_MAGIC_regex_global)))) {
                /* prepare for quick setting of pos */
                sv_magic(PL_reg_sv, (SV*)0,
-                       PERL_MAGIC_regex_global, Nullch, 0);
+                       PERL_MAGIC_regex_global, NULL, 0);
                mg = mg_find(PL_reg_sv, PERL_MAGIC_regex_global);
                mg->mg_len = -1;
            }
@@ -2142,7 +2140,7 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
            SAVEDESTRUCTOR_X(restore_pos, 0);
         }
         if (!PL_reg_curpm) {
-           Newz(22, PL_reg_curpm, 1, PMOP);
+           Newxz(PL_reg_curpm, 1, PMOP);
 #ifdef USE_ITHREADS
             {
                 SV* repointer = newSViv(0);
@@ -2163,13 +2161,13 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
                $` inside (?{}) could fail... */
            PL_reg_oldsaved = prog->subbeg;
            PL_reg_oldsavedlen = prog->sublen;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
            PL_nrs = prog->saved_copy;
 #endif
            RX_MATCH_COPIED_off(prog);
        }
        else
-           PL_reg_oldsaved = Nullch;
+           PL_reg_oldsaved = NULL;
        prog->subbeg = PL_bostr;
        prog->sublen = PL_regeol - PL_bostr; /* strend may have been modified */
     }
@@ -2188,7 +2186,7 @@ S_regtry(pTHX_ regexp *prog, char *startpos)
         if(PL_reg_start_tmp)
             Renew(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
         else
-            New(22, PL_reg_start_tmp, PL_reg_start_tmpl, char*);
+            Newx(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
     }
 
     /* XXXX What this code is doing here?!!!  There should be no need
@@ -2317,8 +2315,7 @@ typedef union re_unwind_t {
            ENTER;                                                       \
            SAVETMPS;                                                    \
            bufflen = TRIE_INITAL_ACCEPT_BUFFLEN ;                       \
-           sv_accept_buff=NEWSV( 1234,                                  \
-             bufflen * sizeof(reg_trie_accepted) - 1 );                 \
+           sv_accept_buff=newSV(bufflen * sizeof(reg_trie_accepted) - 1 );\
            SvCUR_set( sv_accept_buff, sizeof(reg_trie_accepted) );      \
            SvPOK_on( sv_accept_buff );                                  \
            sv_2mortal( sv_accept_buff );                                \
@@ -2380,6 +2377,7 @@ typedef union re_unwind_t {
 STATIC I32                     /* 0 failure, 1 success */
 S_regmatch(pTHX_ regnode *prog)
 {
+    dVAR;
     register regnode *scan;    /* Current node. */
     regnode *next;             /* Next node. */
     regnode *inner;            /* Next node in internal branch. */
@@ -2387,29 +2385,30 @@ S_regmatch(pTHX_ regnode *prog)
                                   function of same name */
     register I32 n;            /* no or next */
     register I32 ln = 0;       /* len or last */
-    register char *s = Nullch; /* operand or save */
+    register char *s = NULL;   /* operand or save */
     register char *locinput = PL_reginput;
     register I32 c1 = 0, c2 = 0, paren;        /* case fold search, parenth */
     int minmod = 0, sw = 0, logical = 0;
     I32 unwind = 0;
 
     /* used by the trie code */
-    SV                 *sv_accept_buff = 0;  /* accepting states we have traversed */
-    reg_trie_accepted  *accept_buff = 0;     /* "" */
+    SV                 *sv_accept_buff = NULL; /* accepting states we have traversed */
+    reg_trie_accepted  *accept_buff = NULL;  /* "" */
     reg_trie_data      *trie;                /* what trie are we using right now */
     U32 accepted = 0;                        /* how many accepting states we have seen*/
 
 #if 0
     I32 firstcp = PL_savestack_ix;
 #endif
-    register bool do_utf8 = PL_reg_match_utf8;
+    register const bool do_utf8 = PL_reg_match_utf8;
 #ifdef DEBUGGING
-    SV *dsv0 = PERL_DEBUG_PAD_ZERO(0);
-    SV *dsv1 = PERL_DEBUG_PAD_ZERO(1);
-    SV *dsv2 = PERL_DEBUG_PAD_ZERO(2);
+    SV * const dsv0 = PERL_DEBUG_PAD_ZERO(0);
+    SV * const dsv1 = PERL_DEBUG_PAD_ZERO(1);
+    SV * const dsv2 = PERL_DEBUG_PAD_ZERO(2);
 
     SV *re_debug_flags = NULL;
 #endif
+    U32 uniflags = ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY;
 
     GET_RE_DEBUG_FLAGS;
 
@@ -2424,9 +2423,9 @@ S_regmatch(pTHX_ regnode *prog)
     while (scan != NULL) {
 
         DEBUG_EXECUTE_r( {
-           SV *prop = sv_newmortal();
-           int docolor = *PL_colors[0];
-           int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
+           SV * const prop = sv_newmortal();
+           const int docolor = *PL_colors[0];
+           const int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
            int l = (PL_regeol - locinput) > taill ? taill : (PL_regeol - locinput);
            /* The part of the string before starttry has one color
               (pref0_len chars), between starttry and current
@@ -2452,22 +2451,22 @@ S_regmatch(pTHX_ regnode *prog)
                pref0_len = pref_len;
            regprop(prop, scan);
            {
-             char *s0 =
+             const char * const s0 =
                do_utf8 && OP(scan) != CANY ?
                pv_uni_display(dsv0, (U8*)(locinput - pref_len),
                               pref0_len, 60, UNI_DISPLAY_REGEX) :
                locinput - pref_len;
-             int len0 = do_utf8 ? strlen(s0) : pref0_len;
-             char *s1 = do_utf8 && OP(scan) != CANY ?
+             const int len0 = do_utf8 ? strlen(s0) : pref0_len;
+             const char * const s1 = do_utf8 && OP(scan) != CANY ?
                pv_uni_display(dsv1, (U8*)(locinput - pref_len + pref0_len),
                               pref_len - pref0_len, 60, UNI_DISPLAY_REGEX) :
                locinput - pref_len + pref0_len;
-             int len1 = do_utf8 ? strlen(s1) : pref_len - pref0_len;
-             char *s2 = do_utf8 && OP(scan) != CANY ?
+             const int len1 = do_utf8 ? strlen(s1) : pref_len - pref0_len;
+             const char * const s2 = do_utf8 && OP(scan) != CANY ?
                pv_uni_display(dsv2, (U8*)locinput,
                               PL_regeol - locinput, 60, UNI_DISPLAY_REGEX) :
                locinput;
-             int len2 = do_utf8 ? strlen(s2) : l;
+             const int len2 = do_utf8 ? strlen(s2) : l;
              PerlIO_printf(Perl_debug_log,
                            "%4"IVdf" <%s%.*s%s%s%.*s%s%s%s%.*s%s>%*s|%3"IVdf":%*s%s\n",
                            (IV)(locinput - PL_bostr),
@@ -2484,7 +2483,7 @@ S_regmatch(pTHX_ regnode *prog)
                            15 - l - pref_len + 1,
                            "",
                            (IV)(scan - PL_regprogram), PL_regindent*2, "",
-                           SvPVX(prop));
+                           SvPVX_const(prop));
            }
        });
 
@@ -2577,8 +2576,6 @@ S_regmatch(pTHX_ regnode *prog)
        case TRIEF:
        case TRIEFL:
            {
-
-               U32 uniflags = ckWARN( WARN_UTF8 ) ? 0 : UTF8_ALLOW_ANY;
                U8 *uc = ( U8* )locinput;
                U32 state = 1;
                U16 charid = 0;
@@ -2586,7 +2583,6 @@ S_regmatch(pTHX_ regnode *prog)
                UV uvc = 0;
                STRLEN len = 0;
                STRLEN foldlen = 0;
-               U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
                U8 *uscan = (U8*)NULL;
                STRLEN bufflen=0;
                accepted = 0;
@@ -2608,13 +2604,14 @@ S_regmatch(pTHX_ regnode *prog)
 
                    if ( base ) {
 
-                       if ( do_utf8 || UTF ) {
+                       if ( do_utf8 ) {
                            if ( foldlen>0 ) {
                                uvc = utf8n_to_uvuni( uscan, UTF8_MAXLEN, &len, uniflags );
                                foldlen -= len;
                                uscan += len;
                                len=0;
                            } else {
+                               U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
                                uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags );
                                uvc = to_uni_fold( uvc, foldbuf, &foldlen );
                                foldlen -= UNISKIP( uvc );
@@ -2646,7 +2643,6 @@ S_regmatch(pTHX_ regnode *prog)
               from previous if blocks */
        case TRIE:
            {
-               U32 uniflags = ckWARN( WARN_UTF8 ) ? 0 : UTF8_ALLOW_ANY;
                U8 *uc = (U8*)locinput;
                U32 state = 1;
                U16 charid = 0;
@@ -2673,7 +2669,7 @@ S_regmatch(pTHX_ regnode *prog)
 
                    if ( base ) {
 
-                       if ( do_utf8 || UTF ) {
+                       if ( do_utf8 ) {
                            uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags );
                        } else {
                            uvc = (U32)*uc;
@@ -2720,7 +2716,7 @@ S_regmatch(pTHX_ regnode *prog)
                            "%*s  %sonly one match : #%d <%s>%s\n",
                            REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4],
                            accept_buff[ 0 ].wordnum,
-                           tmp ? SvPV_nolen( *tmp ) : "not compiled under -Dr",
+                           tmp ? SvPV_nolen_const( *tmp ) : "not compiled under -Dr",
                            PL_colors[5] );
                    });
                    PL_reginput = (char *)accept_buff[ 0 ].endpos;
@@ -2751,11 +2747,11 @@ S_regmatch(pTHX_ regnode *prog)
                                    best = cur;
                        }
                        DEBUG_EXECUTE_r({
-                           SV **tmp = av_fetch( trie->words, accept_buff[ best ].wordnum - 1, 0 );
+                           SV ** const tmp = av_fetch( trie->words, accept_buff[ best ].wordnum - 1, 0 );
                            PerlIO_printf( Perl_debug_log, "%*s  %strying alternation #%d <%s> at 0x%p%s\n",
                                REPORT_CODE_OFF+PL_regindent*2, "", PL_colors[4],
                                accept_buff[best].wordnum,
-                               tmp ? SvPV_nolen( *tmp ) : "not compiled under -Dr",scan,
+                               tmp ? SvPV_nolen_const( *tmp ) : "not compiled under -Dr",scan,
                                PL_colors[5] );
                        });
                        if ( best<accepted ) {
@@ -2792,18 +2788,17 @@ S_regmatch(pTHX_ regnode *prog)
            if (do_utf8 != UTF) {
                /* The target and the pattern have differing utf8ness. */
                char *l = locinput;
-               char *e = s + ln;
-               STRLEN ulen;
+               const char *e = s + ln;
 
                if (do_utf8) {
                    /* The target is utf8, the pattern is not utf8. */
                    while (s < e) {
+                       STRLEN ulen;
                        if (l >= PL_regeol)
                             sayNO;
                        if (NATIVE_TO_UNI(*(U8*)s) !=
                            utf8n_to_uvuni((U8*)l, UTF8_MAXBYTES, &ulen,
-                                          ckWARN(WARN_UTF8) ?
-                                          0 : UTF8_ALLOW_ANY))
+                                           uniflags))
                             sayNO;
                        l += ulen;
                        s ++;
@@ -2812,12 +2807,12 @@ S_regmatch(pTHX_ regnode *prog)
                else {
                    /* The target is not utf8, the pattern is utf8. */
                    while (s < e) {
+                       STRLEN ulen;
                        if (l >= PL_regeol)
                            sayNO;
                        if (NATIVE_TO_UNI(*((U8*)l)) !=
                            utf8n_to_uvuni((U8*)s, UTF8_MAXBYTES, &ulen,
-                                          ckWARN(WARN_UTF8) ?
-                                          0 : UTF8_ALLOW_ANY))
+                                          uniflags))
                            sayNO;
                        s += ulen;
                        l ++;
@@ -2926,7 +2921,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (!nextchr)
                sayNO;
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(alnum,"a");
+               LOAD_UTF8_CHARCLASS_ALNUM();
                if (!(OP(scan) == ALNUM
                      ? swash_fetch(PL_utf8_alnum, (U8*)locinput, do_utf8)
                      : isALNUM_LC_utf8((U8*)locinput)))
@@ -2949,7 +2944,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (!nextchr && locinput >= PL_regeol)
                sayNO;
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(alnum,"a");
+               LOAD_UTF8_CHARCLASS_ALNUM();
                if (OP(scan) == NALNUM
                    ? swash_fetch(PL_utf8_alnum, (U8*)locinput, do_utf8)
                    : isALNUM_LC_utf8((U8*)locinput))
@@ -2976,13 +2971,13 @@ S_regmatch(pTHX_ regnode *prog)
                if (locinput == PL_bostr)
                    ln = '\n';
                else {
-                   U8 *r = reghop3((U8*)locinput, -1, (U8*)PL_bostr);
+                   const U8 * const r = reghop3((U8*)locinput, -1, (U8*)PL_bostr);
                
                    ln = utf8n_to_uvchr(r, UTF8SKIP(r), 0, 0);
                }
                if (OP(scan) == BOUND || OP(scan) == NBOUND) {
                    ln = isALNUM_uni(ln);
-                   LOAD_UTF8_CHARCLASS(alnum,"a");
+                   LOAD_UTF8_CHARCLASS_ALNUM();
                    n = swash_fetch(PL_utf8_alnum, (U8*)locinput, do_utf8);
                }
                else {
@@ -3014,7 +3009,7 @@ S_regmatch(pTHX_ regnode *prog)
                sayNO;
            if (do_utf8) {
                if (UTF8_IS_CONTINUED(nextchr)) {
-                   LOAD_UTF8_CHARCLASS(space," ");
+                   LOAD_UTF8_CHARCLASS_SPACE();
                    if (!(OP(scan) == SPACE
                          ? swash_fetch(PL_utf8_space, (U8*)locinput, do_utf8)
                          : isSPACE_LC_utf8((U8*)locinput)))
@@ -3044,7 +3039,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (!nextchr && locinput >= PL_regeol)
                sayNO;
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(space," ");
+               LOAD_UTF8_CHARCLASS_SPACE();
                if (OP(scan) == NSPACE
                    ? swash_fetch(PL_utf8_space, (U8*)locinput, do_utf8)
                    : isSPACE_LC_utf8((U8*)locinput))
@@ -3067,7 +3062,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (!nextchr)
                sayNO;
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(digit,"0");
+               LOAD_UTF8_CHARCLASS_DIGIT();
                if (!(OP(scan) == DIGIT
                      ? swash_fetch(PL_utf8_digit, (U8*)locinput, do_utf8)
                      : isDIGIT_LC_utf8((U8*)locinput)))
@@ -3090,7 +3085,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (!nextchr && locinput >= PL_regeol)
                sayNO;
            if (do_utf8) {
-               LOAD_UTF8_CHARCLASS(digit,"0");
+               LOAD_UTF8_CHARCLASS_DIGIT();
                if (OP(scan) == NDIGIT
                    ? swash_fetch(PL_utf8_digit, (U8*)locinput, do_utf8)
                    : isDIGIT_LC_utf8((U8*)locinput))
@@ -3110,7 +3105,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (locinput >= PL_regeol)
                sayNO;
            if  (do_utf8) {
-               LOAD_UTF8_CHARCLASS(mark,"~");
+               LOAD_UTF8_CHARCLASS_MARK();
                if (swash_fetch(PL_utf8_mark,(U8*)locinput, do_utf8))
                    sayNO;
                locinput += PL_utf8skip[nextchr];
@@ -3140,17 +3135,18 @@ S_regmatch(pTHX_ regnode *prog)
            s = PL_bostr + ln;
            if (do_utf8 && OP(scan) != REF) {   /* REF can do byte comparison */
                char *l = locinput;
-               char *e = PL_bostr + PL_regendp[n];
+               const char *e = PL_bostr + PL_regendp[n];
                /*
                 * Note that we can't do the "other character" lookup trick as
                 * in the 8-bit case (no pun intended) because in Unicode we
                 * have to map both upper and title case to lower case.
                 */
                if (OP(scan) == REFF) {
-                   STRLEN ulen1, ulen2;
-                   U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
-                   U8 tmpbuf2[UTF8_MAXBYTES_CASE+1];
                    while (s < e) {
+                       STRLEN ulen1, ulen2;
+                       U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
+                       U8 tmpbuf2[UTF8_MAXBYTES_CASE+1];
+
                        if (l >= PL_regeol)
                            sayNO;
                        toLOWER_utf8((U8*)s, tmpbuf1, &ulen1);
@@ -3193,11 +3189,11 @@ S_regmatch(pTHX_ regnode *prog)
        case EVAL:
        {
            dSP;
-           OP_4tree *oop = PL_op;
-           COP *ocurcop = PL_curcop;
+           OP_4tree * const oop = PL_op;
+           COP * const ocurcop = PL_curcop;
            PAD *old_comppad;
            SV *ret;
-           struct regexp *oreg = PL_reg_re;
+           struct regexp * const oreg = PL_reg_re;
        
            n = ARG(scan);
            PL_op = (OP_4tree*)PL_regdata->data[n];
@@ -3206,7 +3202,7 @@ S_regmatch(pTHX_ regnode *prog)
            PL_regendp[0] = PL_reg_magic->mg_len = locinput - PL_bostr;
 
            {
-               SV **before = SP;
+               SV ** const before = SP;
                CALLRUNOPS(aTHX);                       /* Scalar context. */
                SPAGAIN;
                if (SP == before)
@@ -3223,7 +3219,7 @@ S_regmatch(pTHX_ regnode *prog)
            if (logical) {
                if (logical == 2) {     /* Postponed subexpression. */
                    regexp *re;
-                   MAGIC *mg = Null(MAGIC*);
+                   MAGIC *mg = NULL;
                    re_cc_state state;
                    CHECKPOINT cp, lastcp;
                     int toggleutf;
@@ -3244,15 +3240,15 @@ S_regmatch(pTHX_ regnode *prog)
                    }
                    else {
                        STRLEN len;
-                       char *t = SvPV(ret, len);
+                       const char * const t = SvPV_const(ret, len);
                        PMOP pm;
-                       char *oprecomp = PL_regprecomp;
-                       I32 osize = PL_regsize;
-                       I32 onpar = PL_regnpar;
+                       char * const oprecomp = PL_regprecomp;
+                       const I32 osize = PL_regsize;
+                       const I32 onpar = PL_regnpar;
 
                        Zero(&pm, 1, PMOP);
                         if (DO_UTF8(ret)) pm.op_pmdynflags |= PMdf_DYN_UTF8;
-                       re = CALLREGCOMP(aTHX_ t, t + len, &pm);
+                       re = CALLREGCOMP(aTHX_ (char*)t, (char*)t + len, &pm);
                        if (!(SvFLAGS(ret)
                              & (SVs_TEMP | SVs_PADTMP | SVf_READONLY
                                | SVs_GMG)))
@@ -3264,7 +3260,7 @@ S_regmatch(pTHX_ regnode *prog)
                    }
                    DEBUG_EXECUTE_r(
                        PerlIO_printf(Perl_debug_log,
-                                     "Entering embedded `%s%.60s%s%s'\n",
+                                     "Entering embedded \"%s%.60s%s%s\"\n",
                                      PL_colors[0],
                                      re->precomp,
                                      PL_colors[1],
@@ -3470,7 +3466,7 @@ S_regmatch(pTHX_ regnode *prog)
                PL_regcc = cc.oldcc;
                saySAME(n);
            }
-           /* NOT REACHED */
+           /* NOTREACHED */
        case WHILEM: {
                /*
                 * This is really hard to understand, because after we match
@@ -3483,7 +3479,7 @@ S_regmatch(pTHX_ regnode *prog)
 
                CHECKPOINT cp, lastcp;
                CURCUR* cc = PL_regcc;
-               char *lastloc = cc->lastloc; /* Detection of 0-len. */
+               char * const lastloc = cc->lastloc; /* Detection of 0-len. */
                I32 cache_offset = 0, cache_bit = 0;
                
                n = cc->cur + 1;        /* how many we know we matched */
@@ -3537,7 +3533,7 @@ S_regmatch(pTHX_ regnode *prog)
                    PL_reg_leftiter = PL_reg_maxiter;
                }
                if (PL_reg_leftiter-- == 0) {
-                   I32 size = (PL_reg_maxiter + 7 + POSCACHE_START)/8;
+                   const I32 size = (PL_reg_maxiter + 7 + POSCACHE_START)/8;
                    if (PL_reg_poscache) {
                        if ((I32)PL_reg_poscache_size < size) {
                            Renew(PL_reg_poscache, size, char);
@@ -3547,7 +3543,7 @@ S_regmatch(pTHX_ regnode *prog)
                    }
                    else {
                        PL_reg_poscache_size = size;
-                       Newz(29, PL_reg_poscache, size, char);
+                       Newxz(PL_reg_poscache, size, char);
                    }
                    DEBUG_EXECUTE_r(
                        PerlIO_printf(Perl_debug_log,
@@ -3671,7 +3667,7 @@ S_regmatch(pTHX_ regnode *prog)
                cc->lastloc = lastloc;
                CACHEsayNO;
            }
-           /* NOT REACHED */
+           /* NOTREACHED */
        case BRANCHJ:
            next = scan + ARG(scan);
            if (next == scan)
@@ -3686,13 +3682,11 @@ S_regmatch(pTHX_ regnode *prog)
                if (OP(next) != c1)     /* No choice. */
                    next = inner;       /* Avoid recursion. */
                else {
-                   I32 lastparen = *PL_reglastparen;
-                   I32 unwind1;
-                   re_unwind_branch_t *uw;
-
+                   const I32 lastparen = *PL_reglastparen;
                    /* Put unwinding data on stack */
-                   unwind1 = SSNEWt(1,re_unwind_branch_t);
-                   uw = SSPTRt(unwind1,re_unwind_branch_t);
+                   const I32 unwind1 = SSNEWt(1,re_unwind_branch_t);
+                   re_unwind_branch_t * const uw = SSPTRt(unwind1,re_unwind_branch_t);
+
                    uw->prev = unwind;
                    unwind = unwind1;
                    uw->type = ((c1 == BRANCH)
@@ -3861,6 +3855,7 @@ S_regmatch(pTHX_ regnode *prog)
                }
            }
            sayNO;
+           /* NOTREACHED */
            break;
        }
        case CURLYN:
@@ -3933,16 +3928,13 @@ S_regmatch(pTHX_ regnode *prog)
                             to_utf8_upper((U8*)s, tmpbuf2, &ulen2);
 
                             c1 = utf8n_to_uvuni(tmpbuf1, UTF8_MAXBYTES, 0,
-                                                ckWARN(WARN_UTF8) ?
-                                                0 : UTF8_ALLOW_ANY);
+                                                uniflags);
                             c2 = utf8n_to_uvuni(tmpbuf2, UTF8_MAXBYTES, 0,
-                                                ckWARN(WARN_UTF8) ?
-                                                0 : UTF8_ALLOW_ANY);
+                                                uniflags);
                        }
                        else {
                            c2 = c1 = utf8n_to_uvchr(s, UTF8_MAXBYTES, 0,
-                                                    ckWARN(WARN_UTF8) ?
-                                                    0 : UTF8_ALLOW_ANY);
+                                                    uniflags);
                        }
                    }
                }
@@ -3996,26 +3988,25 @@ S_regmatch(pTHX_ regnode *prog)
                            count = locinput - old;
                        }
                        else {
-                           STRLEN len;
                            if (c1 == c2) {
+                               STRLEN len;
                                /* count initialised to
                                 * utf8_distance(old, locinput) */
                                while (locinput <= e &&
                                       utf8n_to_uvchr((U8*)locinput,
                                                      UTF8_MAXBYTES, &len,
-                                                     ckWARN(WARN_UTF8) ?
-                                                     0 : UTF8_ALLOW_ANY) != (UV)c1) {
+                                                     uniflags) != (UV)c1) {
                                    locinput += len;
                                    count++;
                                }
                            } else {
+                               STRLEN len;
                                /* count initialised to
                                 * utf8_distance(old, locinput) */
                                while (locinput <= e) {
                                    UV c = utf8n_to_uvchr((U8*)locinput,
                                                          UTF8_MAXBYTES, &len,
-                                                         ckWARN(WARN_UTF8) ?
-                                                         0 : UTF8_ALLOW_ANY);
+                                                         uniflags);
                                    if (c == (UV)c1 || c == (UV)c2)
                                        break;
                                    locinput += len;
@@ -4051,8 +4042,7 @@ S_regmatch(pTHX_ regnode *prog)
                        if (do_utf8)
                            c = utf8n_to_uvchr((U8*)PL_reginput,
                                               UTF8_MAXBYTES, 0,
-                                              ckWARN(WARN_UTF8) ?
-                                              0 : UTF8_ALLOW_ANY);
+                                              uniflags);
                        else
                            c = UCHARAT(PL_reginput);
                        /* If it could work, try it. */
@@ -4101,8 +4091,7 @@ S_regmatch(pTHX_ regnode *prog)
                            if (do_utf8)
                                c = utf8n_to_uvchr((U8*)PL_reginput,
                                                   UTF8_MAXBYTES, 0,
-                                                  ckWARN(WARN_UTF8) ?
-                                                  0 : UTF8_ALLOW_ANY);
+                                                  uniflags);
                            else
                                c = UCHARAT(PL_reginput);
                        }
@@ -4124,8 +4113,7 @@ S_regmatch(pTHX_ regnode *prog)
                            if (do_utf8)
                                c = utf8n_to_uvchr((U8*)PL_reginput,
                                                   UTF8_MAXBYTES, 0,
-                                                  ckWARN(WARN_UTF8) ?
-                                                  0 : UTF8_ALLOW_ANY);
+                                                  uniflags);
                            else
                                c = UCHARAT(PL_reginput);
                        }
@@ -4148,14 +4136,22 @@ S_regmatch(pTHX_ regnode *prog)
                re_cc_state *cur_call_cc = PL_reg_call_cc;
                CURCUR *cctmp = PL_regcc;
                regexp *re = PL_reg_re;
-               CHECKPOINT cp, lastcp;
-               
-               cp = regcppush(0);      /* Save *all* the positions. */
+               CHECKPOINT lastcp;
+               I32 tmp;
+
+               /* Save *all* the positions. */
+               const CHECKPOINT cp = regcppush(0);
                REGCP_SET(lastcp);
-               regcp_set_to(PL_reg_call_cc->ss); /* Restore parens of
-                                                   the caller. */
-               PL_reginput = locinput; /* Make position available to
-                                          the callcc. */
+
+               /* Restore parens of the caller. */
+               tmp = PL_savestack_ix;
+               PL_savestack_ix = PL_reg_call_cc->ss;
+               regcppop();
+               PL_savestack_ix = tmp;
+
+               /* Make position available to the callcc. */
+               PL_reginput = locinput;
+
                cache_re(PL_reg_call_cc->re);
                PL_regcc = PL_reg_call_cc->cc;
                PL_reg_call_cc = PL_reg_call_cc->prev;
@@ -4294,14 +4290,14 @@ no:
 no_final:
 do_no:
     if (unwind) {
-       re_unwind_t *uw = SSPTRt(unwind,re_unwind_t);
+       re_unwind_t * const uw = SSPTRt(unwind,re_unwind_t);
 
        switch (uw->type) {
        case RE_UNWIND_BRANCH:
        case RE_UNWIND_BRANCHJ:
        {
-           re_unwind_branch_t *uwb = &(uw->branch);
-           I32 lastparen = uwb->lastparen;
+           re_unwind_branch_t * const uwb = &(uw->branch);
+           const I32 lastparen = uwb->lastparen;
        
            REGCP_UNWIND(uwb->lastcp);
            for (n = *PL_reglastparen; n > lastparen; n--)
@@ -4318,7 +4314,6 @@ do_no:
                goto do_no;
            }
            /* Have more choice yet.  Reuse the same uwb.  */
-           /*SUPPRESS 560*/
            if ((n = (uwb->type == RE_UNWIND_BRANCH
                      ? NEXT_OFF(next) : ARG(next))))
                next += n;
@@ -4336,11 +4331,11 @@ do_no:
 
            goto reenter;
        }
-       /* NOT REACHED */
+       /* NOTREACHED */
        default:
            Perl_croak(aTHX_ "regexp unwind memory corruption");
        }
-       /* NOT REACHED */
+       /* NOTREACHED */
     }
 #ifdef DEBUGGING
     PL_regindent--;
@@ -4357,8 +4352,9 @@ do_no:
  * rather than incrementing count on every character.  [Er, except utf8.]]
  */
 STATIC I32
-S_regrepeat(pTHX_ regnode *p, I32 max)
+S_regrepeat(pTHX_ const regnode *p, I32 max)
 {
+    dVAR;
     register char *scan;
     register I32 c;
     register char *loceol = PL_regeol;
@@ -4431,7 +4427,7 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
     case ALNUM:
        if (do_utf8) {
            loceol = PL_regeol;
-           LOAD_UTF8_CHARCLASS(alnum,"a");
+           LOAD_UTF8_CHARCLASS_ALNUM();
            while (hardcount < max && scan < loceol &&
                   swash_fetch(PL_utf8_alnum, (U8*)scan, do_utf8)) {
                scan += UTF8SKIP(scan);
@@ -4459,7 +4455,7 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
     case NALNUM:
        if (do_utf8) {
            loceol = PL_regeol;
-           LOAD_UTF8_CHARCLASS(alnum,"a");
+           LOAD_UTF8_CHARCLASS_ALNUM();
            while (hardcount < max && scan < loceol &&
                   !swash_fetch(PL_utf8_alnum, (U8*)scan, do_utf8)) {
                scan += UTF8SKIP(scan);
@@ -4487,7 +4483,7 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
     case SPACE:
        if (do_utf8) {
            loceol = PL_regeol;
-           LOAD_UTF8_CHARCLASS(space," ");
+           LOAD_UTF8_CHARCLASS_SPACE();
            while (hardcount < max && scan < loceol &&
                   (*scan == ' ' ||
                    swash_fetch(PL_utf8_space,(U8*)scan, do_utf8))) {
@@ -4516,7 +4512,7 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
     case NSPACE:
        if (do_utf8) {
            loceol = PL_regeol;
-           LOAD_UTF8_CHARCLASS(space," ");
+           LOAD_UTF8_CHARCLASS_SPACE();
            while (hardcount < max && scan < loceol &&
                   !(*scan == ' ' ||
                     swash_fetch(PL_utf8_space,(U8*)scan, do_utf8))) {
@@ -4545,7 +4541,7 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
     case DIGIT:
        if (do_utf8) {
            loceol = PL_regeol;
-           LOAD_UTF8_CHARCLASS(digit,"0");
+           LOAD_UTF8_CHARCLASS_DIGIT();
            while (hardcount < max && scan < loceol &&
                   swash_fetch(PL_utf8_digit, (U8*)scan, do_utf8)) {
                scan += UTF8SKIP(scan);
@@ -4559,7 +4555,7 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
     case NDIGIT:
        if (do_utf8) {
            loceol = PL_regeol;
-           LOAD_UTF8_CHARCLASS(digit,"0");
+           LOAD_UTF8_CHARCLASS_DIGIT();
            while (hardcount < max && scan < loceol &&
                   !swash_fetch(PL_utf8_digit, (U8*)scan, do_utf8)) {
                scan += UTF8SKIP(scan);
@@ -4582,13 +4578,13 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
 
     DEBUG_r({
                SV *re_debug_flags = NULL;
-               SV *prop = sv_newmortal();
+               SV * const prop = sv_newmortal();
                 GET_RE_DEBUG_FLAGS;
                 DEBUG_EXECUTE_r({
                regprop(prop, p);
                PerlIO_printf(Perl_debug_log,
                              "%*s  %s can match %"IVdf" times out of %"IVdf"...\n",
-                             REPORT_CODE_OFF+1, "", SvPVX(prop),(IV)c,(IV)max);
+                             REPORT_CODE_OFF+1, "", SvPVX_const(prop),(IV)c,(IV)max);
        });
        });
 
@@ -4604,7 +4600,8 @@ S_regrepeat(pTHX_ regnode *p, I32 max)
 STATIC I32
 S_regrepeat_hard(pTHX_ regnode *p, I32 max, I32 *lp)
 {
-    register char *scan = Nullch;
+    dVAR;
+    register char *scan = NULL;
     register char *start;
     register char *loceol = PL_regeol;
     I32 l = 0;
@@ -4652,26 +4649,27 @@ S_regrepeat_hard(pTHX_ regnode *p, I32 max, I32 *lp)
 */
 
 SV *
-Perl_regclass_swash(pTHX_ register regnode* node, bool doinit, SV** listsvp, SV **altsvp)
+Perl_regclass_swash(pTHX_ register const regnode* node, bool doinit, SV** listsvp, SV **altsvp)
 {
+    dVAR;
     SV *sw  = NULL;
     SV *si  = NULL;
     SV *alt = NULL;
 
     if (PL_regdata && PL_regdata->count) {
-       U32 n = ARG(node);
+       const U32 n = ARG(node);
 
        if (PL_regdata->what[n] == 's') {
-           SV *rv = (SV*)PL_regdata->data[n];
-           AV *av = (AV*)SvRV((SV*)rv);
-           SV **ary = AvARRAY(av);
+           SV * const rv = (SV*)PL_regdata->data[n];
+           AV * const av = (AV*)SvRV((SV*)rv);
+           SV **const ary = AvARRAY(av);
            SV **a, **b;
        
-           /* See the end of regcomp.c:S_reglass() for
+           /* See the end of regcomp.c:S_regclass() for
             * documentation of these array elements. */
 
            si = *ary;
-           a  = SvTYPE(ary[1]) == SVt_RV   ? &ary[1] : 0;
+           a  = SvROK(ary[1]) ? &ary[1] : 0;
            b  = SvTYPE(ary[2]) == SVt_PVAV ? &ary[2] : 0;
 
            if (a)
@@ -4704,17 +4702,22 @@ Perl_regclass_swash(pTHX_ register regnode* node, bool doinit, SV** listsvp, SV
  */
 
 STATIC bool
-S_reginclass(pTHX_ register regnode *n, register U8* p, STRLEN* lenp, register bool do_utf8)
+S_reginclass(pTHX_ register const regnode *n, register const U8* p, STRLEN* lenp, register bool do_utf8)
 {
-    char flags = ANYOF_FLAGS(n);
+    dVAR;
+    const char flags = ANYOF_FLAGS(n);
     bool match = FALSE;
     UV c = *p;
     STRLEN len = 0;
     STRLEN plen;
 
-    if (do_utf8 && !UTF8_IS_INVARIANT(c))
-        c = utf8n_to_uvchr(p, UTF8_MAXBYTES, &len,
-                           ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY);
+    if (do_utf8 && !UTF8_IS_INVARIANT(c)) {
+       c = utf8n_to_uvchr(p, UTF8_MAXBYTES, &len,
+                           ckWARN(WARN_UTF8) ? UTF8_CHECK_ONLY :
+                                       UTF8_ALLOW_ANYUV|UTF8_CHECK_ONLY);
+       if (len == (STRLEN)-1)
+           Perl_croak(aTHX_ "Malformed UTF-8 character (fatal)");
+    }
 
     plen = lenp ? *lenp : UNISKIP(NATIVE_TO_UNI(c));
     if (do_utf8 || (flags & ANYOF_UNICODE)) {
@@ -4728,7 +4731,7 @@ S_reginclass(pTHX_ register regnode *n, register U8* p, STRLEN* lenp, register b
            match = TRUE;
        if (!match) {
            AV *av;
-           SV *sw = regclass_swash(n, TRUE, 0, (SV**)&av);
+           SV * const sw = regclass_swash(n, TRUE, 0, (SV**)&av);
        
            if (sw) {
                if (swash_fetch(sw, p, do_utf8))
@@ -4736,11 +4739,10 @@ S_reginclass(pTHX_ register regnode *n, register U8* p, STRLEN* lenp, register b
                else if (flags & ANYOF_FOLD) {
                    if (!match && lenp && av) {
                        I32 i;
-                     
                        for (i = 0; i <= av_len(av); i++) {
-                           SV* sv = *av_fetch(av, i, FALSE);
+                           SV* const sv = *av_fetch(av, i, FALSE);
                            STRLEN len;
-                           char *s = SvPV(sv, len);
+                           const char * const s = SvPV_const(sv, len);
                        
                            if (len <= plen && memEQ(s, (char*)p, len)) {
                                *lenp = len;
@@ -4825,12 +4827,14 @@ S_reginclass(pTHX_ register regnode *n, register U8* p, STRLEN* lenp, register b
 STATIC U8 *
 S_reghop(pTHX_ U8 *s, I32 off)
 {
-    return S_reghop3(aTHX_ s, off, (U8*)(off >= 0 ? PL_regeol : PL_bostr));
+    dVAR;
+    return S_reghop3(s, off, (U8*)(off >= 0 ? PL_regeol : PL_bostr));
 }
 
 STATIC U8 *
-S_reghop3(pTHX_ U8 *s, I32 off, U8* lim)
+S_reghop3(U8 *s, I32 off, U8* lim)
 {
+    dVAR;
     if (off >= 0) {
        while (off-- && s < lim) {
            /* XXX could check well-formedness here */
@@ -4855,12 +4859,14 @@ S_reghop3(pTHX_ U8 *s, I32 off, U8* lim)
 STATIC U8 *
 S_reghopmaybe(pTHX_ U8 *s, I32 off)
 {
-    return S_reghopmaybe3(aTHX_ s, off, (U8*)(off >= 0 ? PL_regeol : PL_bostr));
+    dVAR;
+    return S_reghopmaybe3(s, off, (U8*)(off >= 0 ? PL_regeol : PL_bostr));
 }
 
 STATIC U8 *
-S_reghopmaybe3(pTHX_ U8* s, I32 off, U8* lim)
+S_reghopmaybe3(U8* s, I32 off, U8* lim)
 {
+    dVAR;
     if (off >= 0) {
        while (off-- && s < lim) {
            /* XXX could check well-formedness here */
@@ -4891,12 +4897,13 @@ S_reghopmaybe3(pTHX_ U8* s, I32 off, U8* lim)
 static void
 restore_pos(pTHX_ void *arg)
 {
-    (void)arg; /* unused */
+    dVAR;
+    PERL_UNUSED_ARG(arg);
     if (PL_reg_eval_set) {
        if (PL_reg_oldsaved) {
            PL_reg_re->subbeg = PL_reg_oldsaved;
            PL_reg_re->sublen = PL_reg_oldsavedlen;
-#ifdef PERL_COPY_ON_WRITE
+#ifdef PERL_OLD_COPY_ON_WRITE
            PL_reg_re->saved_copy = PL_nrs;
 #endif
            RX_MATCH_COPIED_on(PL_reg_re);
@@ -4910,8 +4917,8 @@ restore_pos(pTHX_ void *arg)
 STATIC void
 S_to_utf8_substr(pTHX_ register regexp *prog)
 {
-    SV* sv;
     if (prog->float_substr && !prog->float_utf8) {
+       SV* sv;
        prog->float_utf8 = sv = newSVsv(prog->float_substr);
        sv_utf8_upgrade(sv);
        if (SvTAIL(prog->float_substr))
@@ -4920,6 +4927,7 @@ S_to_utf8_substr(pTHX_ register regexp *prog)
            prog->check_utf8 = sv;
     }
     if (prog->anchored_substr && !prog->anchored_utf8) {
+       SV* sv;
        prog->anchored_utf8 = sv = newSVsv(prog->anchored_substr);
        sv_utf8_upgrade(sv);
        if (SvTAIL(prog->anchored_substr))
@@ -4932,8 +4940,9 @@ S_to_utf8_substr(pTHX_ register regexp *prog)
 STATIC void
 S_to_byte_substr(pTHX_ register regexp *prog)
 {
-    SV* sv;
+    dVAR;
     if (prog->float_utf8 && !prog->float_substr) {
+       SV* sv;
        prog->float_substr = sv = newSVsv(prog->float_utf8);
        if (sv_utf8_downgrade(sv, TRUE)) {
            if (SvTAIL(prog->float_utf8))
@@ -4946,6 +4955,7 @@ S_to_byte_substr(pTHX_ register regexp *prog)
            prog->check_substr = sv;
     }
     if (prog->anchored_utf8 && !prog->anchored_substr) {
+       SV* sv;
        prog->anchored_substr = sv = newSVsv(prog->anchored_utf8);
        if (sv_utf8_downgrade(sv, TRUE)) {
            if (SvTAIL(prog->anchored_utf8))
@@ -4958,3 +4968,13 @@ S_to_byte_substr(pTHX_ register regexp *prog)
            prog->check_substr = sv;
     }
 }
+
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */