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[REPOST] [PATCH] Remove superfluous counter in threads
[perl5.git] / regcomp.c
index 86b9140..ce24f44 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -282,27 +282,6 @@ static const scan_data_t zero_scan_data =
 } STMT_END
 
 /*
- * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
- * args. Show regex, up to a maximum length. If it's too long, chop and add
- * "...".
- */
-#define        FAIL2(pat,msg) STMT_START {                                     \
-    const char *ellipses = "";                                         \
-    IV len = RExC_end - RExC_precomp;                                  \
-                                                                       \
-    if (!SIZE_ONLY)                                                    \
-       SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                      \
-    if (len > RegexLengthToShowInErrorMessages) {                      \
-       /* chop 10 shorter than the max, to ensure meaning of "..." */  \
-       len = RegexLengthToShowInErrorMessages - 10;                    \
-       ellipses = "...";                                               \
-    }                                                                  \
-    S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                      \
-           msg, (int)len, RExC_precomp, ellipses);                     \
-} STMT_END
-
-
-/*
  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
  */
 #define        Simple_vFAIL(m) STMT_START {                                    \
@@ -465,7 +444,7 @@ static void clear_re(pTHX_ void *r);
    floating substrings if needed. */
 
 STATIC void
-S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
+S_scan_commit(pTHX_ const RExC_state_t *pRExC_state, scan_data_t *data)
 {
     const STRLEN l = CHR_SVLEN(data->last_found);
     const STRLEN old_l = CHR_SVLEN(*data->longest);
@@ -497,10 +476,11 @@ S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
     SvCUR_set(data->last_found, 0);
     {
        SV * const sv = data->last_found;
-       MAGIC * const mg =
-           SvUTF8(sv) && SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_utf8) : NULL;
-       if (mg && mg->mg_len > 0)
-           mg->mg_len = 0;
+       if (SvUTF8(sv) && SvMAGICAL(sv)) {
+           MAGIC * const mg = mg_find(sv, PERL_MAGIC_utf8);
+           if (mg)
+               mg->mg_len = 0;
+       }
     }
     data->last_end = -1;
     data->flags &= ~SF_BEFORE_EOL;
@@ -508,7 +488,7 @@ S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
 
 /* Can match anything (initialization) */
 STATIC void
-S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
+S_cl_anything(const RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 {
     ANYOF_CLASS_ZERO(cl);
     ANYOF_BITMAP_SETALL(cl);
@@ -519,7 +499,7 @@ S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *c
 
 /* Can match anything (initialization) */
 STATIC int
-S_cl_is_anything(pTHX_ const struct regnode_charclass_class *cl)
+S_cl_is_anything(const struct regnode_charclass_class *cl)
 {
     int value;
 
@@ -535,7 +515,7 @@ S_cl_is_anything(pTHX_ const struct regnode_charclass_class *cl)
 
 /* Can match anything (initialization) */
 STATIC void
-S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
+S_cl_init(const RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 {
     Zero(cl, 1, struct regnode_charclass_class);
     cl->type = ANYOF;
@@ -543,7 +523,7 @@ S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 }
 
 STATIC void
-S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
+S_cl_init_zero(const RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 {
     Zero(cl, 1, struct regnode_charclass_class);
     cl->type = ANYOF;
@@ -555,7 +535,7 @@ S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *
 /* 'And' a given class with another one.  Can create false positives */
 /* We assume that cl is not inverted */
 STATIC void
-S_cl_and(pTHX_ struct regnode_charclass_class *cl,
+S_cl_and(struct regnode_charclass_class *cl,
        const struct regnode_charclass_class *and_with)
 {
     if (!(and_with->flags & ANYOF_CLASS)
@@ -592,7 +572,7 @@ S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 /* 'OR' a given class with another one.  Can create false positives */
 /* We assume that cl is not inverted */
 STATIC void
-S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, const struct regnode_charclass_class *or_with)
+S_cl_or(const RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, const struct regnode_charclass_class *or_with)
 {
     if (or_with->flags & ANYOF_INVERT) {
        /* We do not use
@@ -765,7 +745,7 @@ and would end up looking like:
     DEBUG_TRIE_COMPILE_r({                                                 \
        SV *tmp;                                                           \
        if ( UTF ) {                                                       \
-           tmp = newSVpvn( "", 0 );                                       \
+           tmp = newSVpvs( "" );                                          \
            pv_uni_display( tmp, uc, len, 60, UNI_DISPLAY_REGEX );         \
        } else {                                                           \
            tmp = Perl_newSVpvf_nocontext( "%c", (int)uvc );               \
@@ -827,7 +807,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     /* first pass, loop through and scan words */
     reg_trie_data *trie;
     regnode *cur;
-    const U32 uniflags = ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY;
+    const U32 uniflags = UTF8_ALLOW_DEFAULT;
     STRLEN len = 0;
     UV uvc = 0;
     U16 curword = 0;
@@ -1036,7 +1016,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                });
 
            } else {
-               /* Its a dupe. So ignore it. */
+               /*EMPTY*/;   /* It's a dupe. So ignore it. */
            }
 
         } /* end second pass */
@@ -1242,7 +1222,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                 });
 
             } else {
-                /* Its a dupe. So ignore it. */
+               /*EMPTY*/;  /* Its a dupe. So ignore it. */
             }
 
         } /* end second pass */
@@ -1557,7 +1537,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
        /* Peephole optimizer: */
        DEBUG_OPTIMISE_r({
          SV * const mysv=sv_newmortal();
-         regprop( mysv, scan);
+         regprop(RExC_rx, mysv, scan);
          PerlIO_printf(Perl_debug_log, "%*speep: %s (0x%08"UVXf")\n",
            (int)depth*2, "", SvPV_nolen_const(mysv), PTR2UV(scan));
        });
@@ -1638,7 +1618,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                 char * const s0 = STRING(scan), *s, *t;
                 char * const s1 = s0 + STR_LEN(scan) - 1;
                 char * const s2 = s1 - 4;
-                const char * const t0 = "\xcc\x88\xcc\x81";
+                const char t0[] = "\xcc\x88\xcc\x81";
                 const char * const t1 = t0 + 3;
 
                 for (s = s0 + 2;
@@ -1699,7 +1679,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
            if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
                I32 max1 = 0, min1 = I32_MAX, num = 0;
                struct regnode_charclass_class accum;
-               regnode *startbranch=scan;
+               regnode * const startbranch=scan;
                
                if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
                    scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
@@ -1852,7 +1832,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                         }
 
                         DEBUG_OPTIMISE_r({
-                            regprop( mysv, tail );
+                            regprop(RExC_rx, mysv, tail );
                             PerlIO_printf( Perl_debug_log, "%*s%s%s%s\n",
                                 (int)depth * 2 + 2, "", "Tail node is:", SvPV_nolen_const( mysv ),
                                 (RExC_seen_evals) ? "[EVAL]" : ""
@@ -1889,16 +1869,16 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                             regnode * const noper_next = regnext( noper );
 
                             DEBUG_OPTIMISE_r({
-                                regprop( mysv, cur);
+                                regprop(RExC_rx, mysv, cur);
                                 PerlIO_printf( Perl_debug_log, "%*s%s",
                                    (int)depth * 2 + 2,"  ", SvPV_nolen_const( mysv ) );
 
-                                regprop( mysv, noper);
+                                regprop(RExC_rx, mysv, noper);
                                 PerlIO_printf( Perl_debug_log, " -> %s",
                                     SvPV_nolen_const(mysv));
 
                                 if ( noper_next ) {
-                                  regprop( mysv, noper_next );
+                                  regprop(RExC_rx, mysv, noper_next );
                                   PerlIO_printf( Perl_debug_log,"\t=> %s\t",
                                     SvPV_nolen_const(mysv));
                                 }
@@ -1916,20 +1896,20 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                                 } else {
                                     DEBUG_OPTIMISE_r(
                                         if (!last ) {
-                                            regprop( mysv, first);
+                                            regprop(RExC_rx, mysv, first);
                                             PerlIO_printf( Perl_debug_log, "%*s%s",
                                               (int)depth * 2 + 2, "F:", SvPV_nolen_const( mysv ) );
-                                            regprop( mysv, NEXTOPER(first) );
+                                            regprop(RExC_rx, mysv, NEXTOPER(first) );
                                             PerlIO_printf( Perl_debug_log, " -> %s\n",
                                               SvPV_nolen_const( mysv ) );
                                         }
                                     );
                                     last = cur;
                                     DEBUG_OPTIMISE_r({
-                                        regprop( mysv, cur);
+                                        regprop(RExC_rx, mysv, cur);
                                         PerlIO_printf( Perl_debug_log, "%*s%s",
                                           (int)depth * 2 + 2, "N:", SvPV_nolen_const( mysv ) );
-                                        regprop( mysv, noper );
+                                        regprop(RExC_rx, mysv, noper );
                                         PerlIO_printf( Perl_debug_log, " -> %s\n",
                                           SvPV_nolen_const( mysv ) );
                                     });
@@ -1957,7 +1937,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                             }
                         }
                         DEBUG_OPTIMISE_r({
-                            regprop( mysv, cur);
+                            regprop(RExC_rx, mysv, cur);
                             PerlIO_printf( Perl_debug_log,
                               "%*s%s\t(0x%p,0x%p,0x%p)\n", (int)depth * 2 + 2,
                               "  ", SvPV_nolen_const( mysv ), first, last, cur);
@@ -1999,6 +1979,8 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                        ? I32_MAX : data->pos_min + data->pos_delta;
                }
                sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
+               if (UTF)
+                   SvUTF8_on(data->last_found);
                {
                    SV * const sv = data->last_found;
                    MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ?
@@ -2007,8 +1989,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                        mg->mg_len += utf8_length((U8*)STRING(scan),
                                                  (U8*)STRING(scan)+STR_LEN(scan));
                }
-               if (UTF)
-                   SvUTF8_on(data->last_found);
                data->last_end = data->pos_min + l;
                data->pos_min += l; /* As in the first entry. */
                data->flags &= ~SF_BEFORE_EOL;
@@ -2048,15 +2028,17 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
            UV uc = *((U8*)STRING(scan));
 
            /* Search for fixed substrings supports EXACT only. */
-           if (flags & SCF_DO_SUBSTR)
+           if (flags & SCF_DO_SUBSTR) {
+               assert(data);
                scan_commit(pRExC_state, data);
+           }
            if (UTF) {
-               U8 *s = (U8 *)STRING(scan);
+               const U8 * const s = (U8 *)STRING(scan);
                l = utf8_length(s, s + l);
                uc = utf8_to_uvchr(s, NULL);
            }
            min += l;
-           if (data && (flags & SCF_DO_SUBSTR))
+           if (flags & SCF_DO_SUBSTR)
                data->pos_min += l;
            if (flags & SCF_DO_STCLASS_AND) {
                /* Check whether it is compatible with what we know already! */
@@ -2092,7 +2074,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
        else if (strchr((const char*)PL_varies,OP(scan))) {
            I32 mincount, maxcount, minnext, deltanext, fl = 0;
            I32 f = flags, pos_before = 0;
-           regnode *oscan = scan;
+           regnode * const oscan = scan;
            struct regnode_charclass_class this_class;
            struct regnode_charclass_class *oclass = NULL;
            I32 next_is_eval = 0;
@@ -2226,7 +2208,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                      && !deltanext && minnext == 1 ) {
                    /* Try to optimize to CURLYN.  */
                    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
-                   regnode *nxt1 = nxt;
+                   regnode * const nxt1 = nxt;
 #ifdef DEBUGGING
                    regnode *nxt2;
 #endif
@@ -2355,7 +2337,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                        I32 b = pos_before >= data->last_start_min
                            ? pos_before : data->last_start_min;
                        STRLEN l;
-                       const char *s = SvPV_const(data->last_found, l);
+                       const char * const s = SvPV_const(data->last_found, l);
                        I32 old = b - data->last_start_min;
 #endif
 
@@ -2404,7 +2386,13 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
                            the group.  */
                        scan_commit(pRExC_state,data);
                        if (mincount && last_str) {
-                           sv_setsv(data->last_found, last_str);
+                           SV * const sv = data->last_found;
+                           MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ?
+                               mg_find(sv, PERL_MAGIC_utf8) : NULL;
+
+                           if (mg)
+                               mg->mg_len = -1;
+                           sv_setsv(sv, last_str);
                            data->last_end = data->pos_min;
                            data->last_start_min =
                                data->pos_min - CHR_SVLEN(last_str);
@@ -2746,7 +2734,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap,
 }
 
 STATIC I32
-S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, const char *s)
+S_add_data(RExC_state_t *pRExC_state, I32 n, const char *s)
 {
     if (RExC_rx->data) {
        Renewc(RExC_rx->data,
@@ -2891,6 +2879,7 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
 #endif
     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
     r->nparens = RExC_npar - 1;        /* set early to validate backrefs */
+    r->lastparen = 0;                  /* mg.c reads this.  */
 
     r->substrs = 0;                    /* Useful during FAIL. */
     r->startp = 0;                     /* Useful during FAIL. */
@@ -2966,7 +2955,7 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
       again:
        if (PL_regkind[(U8)OP(first)] == EXACT) {
            if (OP(first) == EXACT)
-                     /* Empty, get anchored substr later. */
+               /*EMPTY*/;      /* Empty, get anchored substr later. */
            else if ((OP(first) == EXACTF || OP(first) == EXACTFL))
                r->regstclass = first;
        }
@@ -3121,9 +3110,8 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
                       struct regnode_charclass_class);
            r->regstclass = (regnode*)RExC_rx->data->data[n];
            r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
-           PL_regdata = r->data; /* for regprop() */
            DEBUG_COMPILE_r({ SV *sv = sv_newmortal();
-                     regprop(sv, (regnode*)data.start_class);
+                     regprop(r, sv, (regnode*)data.start_class);
                      PerlIO_printf(Perl_debug_log,
                                    "synthetic stclass \"%s\".\n",
                                    SvPVX_const(sv));});
@@ -3178,7 +3166,7 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
            r->regstclass = (regnode*)RExC_rx->data->data[n];
            r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
            DEBUG_COMPILE_r({ SV* sv = sv_newmortal();
-                     regprop(sv, (regnode*)data.start_class);
+                     regprop(r, sv, (regnode*)data.start_class);
                      PerlIO_printf(Perl_debug_log,
                                    "synthetic stclass \"%s\".\n",
                                    SvPVX_const(sv));});
@@ -3196,7 +3184,6 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
        r->reganch |= ROPT_CANY_SEEN;
     Newxz(r->startp, RExC_npar, I32);
     Newxz(r->endp, RExC_npar, I32);
-    PL_regdata = r->data; /* for regprop() */
     DEBUG_COMPILE_r(regdump(r));
     return(r);
 }
@@ -3222,21 +3209,20 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
     register I32 parno = 0;
     I32 flags;
     const I32 oregflags = RExC_flags;
-    I32 have_branch = 0;
-    I32 open = 0;
+    bool have_branch = 0;
+    bool is_open = 0;
 
     /* for (?g), (?gc), and (?o) warnings; warning
        about (?c) will warn about (?g) -- japhy    */
 
+#define WASTED_O  0x01
+#define WASTED_G  0x02
+#define WASTED_C  0x04
+#define WASTED_GC (0x02|0x04)
     I32 wastedflags = 0x00;
-    const I32 wasted_o  = 0x01;
-    const I32 wasted_g  = 0x02;
-    const I32 wasted_gc = 0x02 | 0x04;
-    const I32 wasted_c  = 0x04;
 
     char * parse_start = RExC_parse; /* MJD */
     char * const oregcomp_parse = RExC_parse;
-    char c;
 
     *flagp = 0;                                /* Tentatively. */
 
@@ -3246,7 +3232,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
        if (*RExC_parse == '?') { /* (?...) */
            U32 posflags = 0, negflags = 0;
            U32 *flagsp = &posflags;
-           int logical = 0;
+           bool is_logical = 0;
            const char * const seqstart = RExC_parse;
 
            RExC_parse++;
@@ -3283,7 +3269,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
                    vWARNdep(RExC_parse, "(?p{}) is deprecated - use (??{})");
                /* FALL THROUGH*/
            case '?':           /* (??...) */
-               logical = 1;
+               is_logical = 1;
                if (*RExC_parse != '{')
                    goto unknown;
                paren = *RExC_parse++;
@@ -3293,32 +3279,28 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
                I32 count = 1, n = 0;
                char c;
                char *s = RExC_parse;
-               SV *sv;
-               OP_4tree *sop, *rop;
 
                RExC_seen_zerolen++;
                RExC_seen |= REG_SEEN_EVAL;
                while (count && (c = *RExC_parse)) {
-                   if (c == '\\' && RExC_parse[1])
-                       RExC_parse++;
+                   if (c == '\\') {
+                       if (RExC_parse[1])
+                           RExC_parse++;
+                   }
                    else if (c == '{')
                        count++;
                    else if (c == '}')
                        count--;
                    RExC_parse++;
                }
-               if (*RExC_parse != ')')
-               {
+               if (*RExC_parse != ')') {
                    RExC_parse = s;             
                    vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
                }
                if (!SIZE_ONLY) {
                    PAD *pad;
-               
-                   if (RExC_parse - 1 - s)
-                       sv = newSVpvn(s, RExC_parse - 1 - s);
-                   else
-                       sv = newSVpvs("");
+                   OP_4tree *sop, *rop;
+                   SV * const sv = newSVpvn(s, RExC_parse - 1 - s);
 
                    ENTER;
                    Perl_save_re_context(aTHX);
@@ -3347,7 +3329,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
                }
 
                nextchar(pRExC_state);
-               if (logical) {
+               if (is_logical) {
                    ret = reg_node(pRExC_state, LOGICAL);
                    if (!SIZE_ONLY)
                        ret->flags = 2;
@@ -3377,6 +3359,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
                }
                else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
                     /* (?(1)...) */
+                   char c;
                    parno = atoi(RExC_parse++);
 
                    while (isDIGIT(*RExC_parse))
@@ -3434,7 +3417,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
 
                    if (*RExC_parse == 'o' || *RExC_parse == 'g') {
                        if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
-                           I32 wflagbit = *RExC_parse == 'o' ? wasted_o : wasted_g;
+                           const I32 wflagbit = *RExC_parse == 'o' ? WASTED_O : WASTED_G;
                            if (! (wastedflags & wflagbit) ) {
                                wastedflags |= wflagbit;
                                vWARN5(
@@ -3450,8 +3433,8 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
                    }
                    else if (*RExC_parse == 'c') {
                        if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
-                           if (! (wastedflags & wasted_c) ) {
-                               wastedflags |= wasted_gc;
+                           if (! (wastedflags & WASTED_C) ) {
+                               wastedflags |= WASTED_GC;
                                vWARN3(
                                    RExC_parse + 1,
                                    "Useless (%sc) - %suse /gc modifier",
@@ -3494,7 +3477,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
            ret = reganode(pRExC_state, OPEN, parno);
             Set_Node_Length(ret, 1); /* MJD */
             Set_Node_Offset(ret, RExC_parse); /* MJD */
-           open = 1;
+           is_open = 1;
        }
     }
     else                        /* ! paren */
@@ -3523,7 +3506,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
     else if (paren == ':') {
        *flagp |= flags&SIMPLE;
     }
-    if (open) {                                /* Starts with OPEN. */
+    if (is_open) {                             /* Starts with OPEN. */
        regtail(pRExC_state, ret, br);          /* OPEN -> first. */
     }
     else if (paren != '?')             /* Not Conditional */
@@ -3683,7 +3666,7 @@ S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
        *flagp |= flags&SIMPLE;
     }
 
-    return(ret);
+    return ret;
 }
 
 /*
@@ -4292,7 +4275,7 @@ tryagain:
                    if (UTF8_IS_START(*p) && UTF) {
                        STRLEN numlen;
                        ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
-                                              &numlen, 0);
+                                              &numlen, UTF8_ALLOW_DEFAULT);
                        p += numlen;
                    }
                    else
@@ -4437,7 +4420,7 @@ tryagain:
 }
 
 STATIC char *
-S_regwhite(pTHX_ char *p, const char *e)
+S_regwhite(char *p, const char *e)
 {
     while (p < e) {
        if (isSPACE(*p))
@@ -4473,7 +4456,7 @@ S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
        /* I smell either [: or [= or [. -- POSIX has been here, right? */
        POSIXCC(UCHARAT(RExC_parse))) {
        const char c = UCHARAT(RExC_parse);
-       char* s = RExC_parse++;
+       char* const s = RExC_parse++;
        
        while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
            RExC_parse++;
@@ -4685,8 +4668,10 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
            ANYOF_FLAGS(ret) |= ANYOF_INVERT;
     }
 
-    if (SIZE_ONLY)
+    if (SIZE_ONLY) {
        RExC_size += ANYOF_SKIP;
+       listsv = &PL_sv_undef; /* For code scanners: listsv always non-NULL. */
+    }
     else {
        RExC_emit += ANYOF_SKIP;
        if (FOLD)
@@ -4717,7 +4702,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
        if (UTF) {
            value = utf8n_to_uvchr((U8*)RExC_parse,
                                   RExC_end - RExC_parse,
-                                  &numlen, 0);
+                                  &numlen, UTF8_ALLOW_DEFAULT);
            RExC_parse += numlen;
        }
        else
@@ -4729,7 +4714,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
            if (UTF) {
                value = utf8n_to_uvchr((U8*)RExC_parse,
                                   RExC_end - RExC_parse,
-                                  &numlen, 0);
+                                  &numlen, UTF8_ALLOW_DEFAULT);
                RExC_parse += numlen;
            }
            else
@@ -4777,12 +4762,8 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
                              n--;
                         }
                    }
-                   if (value == 'p')
-                        Perl_sv_catpvf(aTHX_ listsv,
-                                       "+utf8::%.*s\n", (int)n, RExC_parse);
-                   else
-                        Perl_sv_catpvf(aTHX_ listsv,
-                                       "!utf8::%.*s\n", (int)n, RExC_parse);
+                   Perl_sv_catpvf(aTHX_ listsv, "%cutf8::%.*s\n",
+                       (value=='p' ? '+' : '!'), (int)n, RExC_parse);
                }
                RExC_parse = e + 1;
                ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
@@ -4851,14 +4832,12 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
            if (range) {
                if (!SIZE_ONLY) {
                    if (ckWARN(WARN_REGEXP)) {
-                       int w =
+                       const int w =
                            RExC_parse >= rangebegin ?
                            RExC_parse - rangebegin : 0;
                        vWARN4(RExC_parse,
                               "False [] range \"%*.*s\"",
-                              w,
-                              w,
-                              rangebegin);
+                              w, w, rangebegin);
                    }
                    if (prevvalue < 256) {
                        ANYOF_BITMAP_SET(ret, prevvalue);
@@ -5248,10 +5227,8 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
 
        if (range) {
            if (prevvalue > (IV)value) /* b-a */ {
-               Simple_vFAIL4("Invalid [] range \"%*.*s\"",
-                             RExC_parse - rangebegin,
-                             RExC_parse - rangebegin,
-                             rangebegin);
+               const int w = RExC_parse - rangebegin;
+               Simple_vFAIL4("Invalid [] range \"%*.*s\"", w, w, rangebegin);
                range = 0; /* not a valid range */
            }
        }
@@ -5264,14 +5241,12 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
                /* a bad range like \w-, [:word:]- ? */
                if (namedclass > OOB_NAMEDCLASS) {
                    if (ckWARN(WARN_REGEXP)) {
-                       int w =
+                       const int w =
                            RExC_parse >= rangebegin ?
                            RExC_parse - rangebegin : 0;
                        vWARN4(RExC_parse,
                               "False [] range \"%*.*s\"",
-                              w,
-                              w,
-                              rangebegin);
+                              w, w, rangebegin);
                    }
                    if (!SIZE_ONLY)
                        ANYOF_BITMAP_SET(ret, '-');
@@ -5415,7 +5390,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
     }
 
     if (!SIZE_ONLY) {
-       AV *av = newAV();
+       AV * const av = newAV();
        SV *rv;
 
        /* The 0th element stores the character class description
@@ -5439,8 +5414,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
 STATIC char*
 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
 {
-    dVAR;
-    char* retval = RExC_parse++;
+    char* const retval = RExC_parse++;
 
     for (;;) {
        if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
@@ -5615,8 +5589,9 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
 /*
 - regtail - set the next-pointer at the end of a node chain of p to val.
 */
+/* TODO: All three parms should be const */
 STATIC void
-S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
+S_regtail(pTHX_ const RExC_state_t *pRExC_state, regnode *p, const regnode *val)
 {
     dVAR;
     register regnode *scan;
@@ -5644,8 +5619,9 @@ S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
 /*
 - regoptail - regtail on operand of first argument; nop if operandless
 */
+/* TODO: All three parms should be const */
 STATIC void
-S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
+S_regoptail(pTHX_ const RExC_state_t *pRExC_state, regnode *p, const regnode *val)
 {
     dVAR;
     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
@@ -5665,7 +5641,7 @@ S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
  - regcurly - a little FSA that accepts {\d+,?\d*}
  */
 STATIC I32
-S_regcurly(pTHX_ register const char *s)
+S_regcurly(register const char *s)
 {
     if (*s++ != '{')
        return FALSE;
@@ -5687,13 +5663,13 @@ S_regcurly(pTHX_ register const char *s)
  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
  */
 void
-Perl_regdump(pTHX_ regexp *r)
+Perl_regdump(pTHX_ const regexp *r)
 {
 #ifdef DEBUGGING
     dVAR;
     SV * const sv = sv_newmortal();
 
-    (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
+    (void)dumpuntil(r, r->program, r->program + 1, NULL, sv, 0);
 
     /* Header fields of interest. */
     if (r->anchored_substr)
@@ -5745,7 +5721,7 @@ Perl_regdump(pTHX_ regexp *r)
        PerlIO_printf(Perl_debug_log, ") ");
 
     if (r->regstclass) {
-       regprop(sv, r->regstclass);
+       regprop(r, sv, r->regstclass);
        PerlIO_printf(Perl_debug_log, "stclass \"%s\" ", SvPVX_const(sv));
     }
     if (r->reganch & ROPT_ANCH) {
@@ -5783,6 +5759,7 @@ Perl_regdump(pTHX_ regexp *r)
         });
     }
 #else
+    PERL_UNUSED_CONTEXT;
     PERL_UNUSED_ARG(r);
 #endif /* DEBUGGING */
 }
@@ -5791,7 +5768,7 @@ Perl_regdump(pTHX_ regexp *r)
 - regprop - printable representation of opcode
 */
 void
-Perl_regprop(pTHX_ SV *sv, const regnode *o)
+Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
 {
 #ifdef DEBUGGING
     dVAR;
@@ -5823,17 +5800,10 @@ Perl_regprop(pTHX_ SV *sv, const regnode *o)
                       PL_colors[0],
                       len, s,
                       PL_colors[1]);
-    } else if (k == TRIE) {/*
-       this isn't always safe, as Pl_regdata may not be for this regex yet
-       (depending on where its called from) so its being moved to dumpuntil
-       I32 n = ARG(o);
-       reg_trie_data *trie=(reg_trie_data*)PL_regdata->data[n];
-       Perl_sv_catpvf(aTHX_ sv, " (W:%d L:%d C:%d S:%d)",
-                      trie->wordcount,
-                      trie->charcount,
-                      trie->uniquecharcount,
-                      trie->laststate);
-       */
+    } else if (k == TRIE) {
+       /*EMPTY*/;
+       /* print the details od the trie in dumpuntil instead, as
+        * prog->data isn't available here */
     } else if (k == CURLY) {
        if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
            Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
@@ -5919,7 +5889,7 @@ Perl_regprop(pTHX_ SV *sv, const regnode *o)
 
        {
            SV *lv;
-           SV * const sw = regclass_swash(o, FALSE, &lv, 0);
+           SV * const sw = regclass_swash(prog, o, FALSE, &lv, 0);
        
            if (lv) {
                if (sw) {
@@ -5986,6 +5956,7 @@ Perl_regprop(pTHX_ SV *sv, const regnode *o)
     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
        Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
 #else
+    PERL_UNUSED_CONTEXT;
     PERL_UNUSED_ARG(sv);
     PERL_UNUSED_ARG(o);
 #endif /* DEBUGGING */
@@ -5996,6 +5967,8 @@ Perl_re_intuit_string(pTHX_ regexp *prog)
 {                              /* Assume that RE_INTUIT is set */
     dVAR;
     GET_RE_DEBUG_FLAGS_DECL;
+    PERL_UNUSED_CONTEXT;
+
     DEBUG_COMPILE_r(
        {
            const char * const s = SvPV_nolen_const(prog->check_substr
@@ -6021,9 +5994,8 @@ Perl_pregfree(pTHX_ struct regexp *r)
     dVAR;
 #ifdef DEBUGGING
     SV * const dsv = PERL_DEBUG_PAD_ZERO(0);
-    SV * const re_debug_flags=get_sv(RE_DEBUG_FLAGS,0);
 #endif
-
+    GET_RE_DEBUG_FLAGS_DECL;
 
     if (!r || (--r->refcnt > 0))
        return;
@@ -6193,55 +6165,29 @@ void
 Perl_save_re_context(pTHX)
 {
     dVAR;
-    SAVEI32(PL_reg_flags);             /* from regexec.c */
-    SAVEPPTR(PL_bostr);
-    SAVEPPTR(PL_reginput);             /* String-input pointer. */
-    SAVEPPTR(PL_regbol);               /* Beginning of input, for ^ check. */
-    SAVEPPTR(PL_regeol);               /* End of input, for $ check. */
-    SAVEVPTR(PL_regstartp);            /* Pointer to startp array. */
-    SAVEVPTR(PL_regendp);              /* Ditto for endp. */
-    SAVEVPTR(PL_reglastparen);         /* Similarly for lastparen. */
-    SAVEVPTR(PL_reglastcloseparen);    /* Similarly for lastcloseparen. */
-    SAVEPPTR(PL_regtill);              /* How far we are required to go. */
-    SAVEGENERICPV(PL_reg_start_tmp);           /* from regexec.c */
+
+    struct re_save_state *state;
+
+    SAVEVPTR(PL_curcop);
+    SSGROW(SAVESTACK_ALLOC_FOR_RE_SAVE_STATE + 1);
+
+    state = (struct re_save_state *)(PL_savestack + PL_savestack_ix);
+    PL_savestack_ix += SAVESTACK_ALLOC_FOR_RE_SAVE_STATE;
+    SSPUSHINT(SAVEt_RE_STATE);
+
+    Copy(&PL_reg_state, state, 1, struct re_save_state);
+
     PL_reg_start_tmp = 0;
-    SAVEI32(PL_reg_start_tmpl);                /* from regexec.c */
     PL_reg_start_tmpl = 0;
-    SAVEVPTR(PL_regdata);
-    SAVEI32(PL_reg_eval_set);          /* from regexec.c */
-    SAVEI32(PL_regnarrate);            /* from regexec.c */
-    SAVEVPTR(PL_regprogram);           /* from regexec.c */
-    SAVEINT(PL_regindent);             /* from regexec.c */
-    SAVEVPTR(PL_regcc);                        /* from regexec.c */
-    SAVEVPTR(PL_curcop);
-    SAVEVPTR(PL_reg_call_cc);          /* from regexec.c */
-    SAVEVPTR(PL_reg_re);               /* from regexec.c */
-    SAVEPPTR(PL_reg_ganch);            /* from regexec.c */
-    SAVESPTR(PL_reg_sv);               /* from regexec.c */
-    SAVEBOOL(PL_reg_match_utf8);       /* from regexec.c */
-    SAVEVPTR(PL_reg_magic);            /* from regexec.c */
-    SAVEI32(PL_reg_oldpos);                    /* from regexec.c */
-    SAVEVPTR(PL_reg_oldcurpm);         /* from regexec.c */
-    SAVEVPTR(PL_reg_curpm);            /* from regexec.c */
-    SAVEPPTR(PL_reg_oldsaved);         /* old saved substr during match */
     PL_reg_oldsaved = NULL;
-    SAVEI32(PL_reg_oldsavedlen);       /* old length of saved substr during match */
     PL_reg_oldsavedlen = 0;
-#ifdef PERL_OLD_COPY_ON_WRITE
-    SAVESPTR(PL_nrs);
-    PL_nrs = NULL;
-#endif
-    SAVEI32(PL_reg_maxiter);           /* max wait until caching pos */
     PL_reg_maxiter = 0;
-    SAVEI32(PL_reg_leftiter);          /* wait until caching pos */
     PL_reg_leftiter = 0;
-    SAVEGENERICPV(PL_reg_poscache);    /* cache of pos of WHILEM */
     PL_reg_poscache = NULL;
-    SAVEI32(PL_reg_poscache_size);     /* size of pos cache of WHILEM */
     PL_reg_poscache_size = 0;
-    SAVEPPTR(PL_regprecomp);           /* uncompiled string. */
-    SAVEI32(PL_regnpar);               /* () count. */
-    SAVEI32(PL_regsize);               /* from regexec.c */
+#ifdef PERL_OLD_COPY_ON_WRITE
+    PL_nrs = NULL;
+#endif
 
     /* Save $1..$n (#18107: UTF-8 s/(\w+)/uc($1)/e); AMS 20021106. */
     if (PL_curpm) {
@@ -6251,16 +6197,17 @@ Perl_save_re_context(pTHX)
            for (i = 1; i <= rx->nparens; i++) {
                char digits[TYPE_CHARS(long)];
                const STRLEN len = my_sprintf(digits, "%lu", (long)i);
-               GV * const mgv = gv_fetchpvn_flags(digits, len, 0, SVt_PV);
-               if (mgv)
-                   save_scalar(mgv);
+               GV *const *const gvp
+                   = (GV**)hv_fetch(PL_defstash, digits, len, 0);
+
+               if (gvp) {
+                   GV * const gv = *gvp;
+                   if (SvTYPE(gv) == SVt_PVGV && GvSV(gv))
+                       save_scalar(gv);
+               }
            }
        }
     }
-
-#ifdef DEBUGGING
-    SAVEPPTR(PL_reg_starttry);         /* from regexec.c */
-#endif
 }
 
 static void
@@ -6284,12 +6231,13 @@ S_put_byte(pTHX_ SV *sv, int c)
 }
 
 
-STATIC regnode *
-S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
+STATIC const regnode *
+S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
+           const regnode *last, SV* sv, I32 l)
 {
     dVAR;
     register U8 op = EXACT;    /* Arbitrary non-END op. */
-    register regnode *next;
+    register const regnode *next;
 
     while (op != END && (!last || node < last)) {
        /* While that wasn't END last time... */
@@ -6298,11 +6246,11 @@ S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
        op = OP(node);
        if (op == CLOSE)
            l--;        
-       next = regnext(node);
+       next = regnext((regnode *)node);
        /* Where, what. */
        if (OP(node) == OPTIMIZED)
            goto after_print;
-       regprop(sv, node);
+       regprop(r, sv, node);
        PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
                      (int)(2*l + 1), "", SvPVX_const(sv));
        if (next == NULL)               /* Next ptr. */
@@ -6312,19 +6260,19 @@ S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
        (void)PerlIO_putc(Perl_debug_log, '\n');
       after_print:
        if (PL_regkind[(U8)op] == BRANCHJ) {
-           register regnode *nnode = (OP(next) == LONGJMP
-                                      ? regnext(next)
-                                      : next);
+           register const regnode *nnode = (OP(next) == LONGJMP
+                                            ? regnext((regnode *)next)
+                                            : next);
            if (last && nnode > last)
                nnode = last;
-           node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
+           node = dumpuntil(r, start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
        }
        else if (PL_regkind[(U8)op] == BRANCH) {
-           node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
+           node = dumpuntil(r, start, NEXTOPER(node), next, sv, l + 1);
        }
        else if ( PL_regkind[(U8)op]  == TRIE ) {
             const I32 n = ARG(node);
-           const reg_trie_data * const trie = (reg_trie_data*)PL_regdata->data[n];
+           const reg_trie_data * const trie = (reg_trie_data*)r->data->data[n];
             const I32 arry_len = av_len(trie->words)+1;
            I32 word_idx;
            PerlIO_printf(Perl_debug_log,
@@ -6338,7 +6286,7 @@ S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
                       node->flags ? " EVAL mode" : "");
 
            for (word_idx=0; word_idx < arry_len; word_idx++) {
-               SV **elem_ptr=av_fetch(trie->words,word_idx,0);
+               SV ** const elem_ptr = av_fetch(trie->words,word_idx,0);
                if (elem_ptr) {
                    PerlIO_printf(Perl_debug_log, "%*s<%s%s%s>\n",
                       (int)(2*(l+4)), "",
@@ -6361,15 +6309,15 @@ S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
 
        }
        else if ( op == CURLY) {   /* "next" might be very big: optimizer */
-           node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
+           node = dumpuntil(r, start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
                             NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
        }
        else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
-           node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
+           node = dumpuntil(r, 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);
+           node = dumpuntil(r, start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
        }
        else if (op == ANYOF) {
            /* arglen 1 + class block */