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regcomp.c: Reorder cases: in switch
[perl5.git] / regcomp.c
index eaee604..d5bb3a2 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -93,6 +93,8 @@ EXTERN_C const struct regexp_engine my_reg_engine;
 
 #define HAS_NONLATIN1_FOLD_CLOSURE(i) \
  _HAS_NONLATIN1_FOLD_CLOSURE_ONLY_FOR_USE_BY_REGCOMP_DOT_C_AND_REGEXEC_DOT_C(i)
+#define HAS_NONLATIN1_SIMPLE_FOLD_CLOSURE(i) \
+ _HAS_NONLATIN1_SIMPLE_FOLD_CLOSURE_ONLY_FOR_USE_BY_REGCOMP_DOT_C_AND_REGEXEC_DOT_C(i)
 #define IS_NON_FINAL_FOLD(c) _IS_NON_FINAL_FOLD_ONLY_FOR_USE_BY_REGCOMP_DOT_C(c)
 #define IS_IN_SOME_FOLD_L1(c) _IS_IN_SOME_FOLD_ONLY_FOR_USE_BY_REGCOMP_DOT_C(c)
 
@@ -223,7 +225,7 @@ struct RExC_state_t {
 
 #define        ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 #define        ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
-       ((*s) == '{' && regcurly(s, FALSE)))
+       ((*s) == '{' && regcurly(s)))
 
 /*
  * Flags to be passed up and down.
@@ -893,7 +895,7 @@ S_ssc_anything(pTHX_ regnode_ssc *ssc)
 }
 
 STATIC int
-S_ssc_is_anything(pTHX_ const regnode_ssc *ssc)
+S_ssc_is_anything(const regnode_ssc *ssc)
 {
     /* Returns TRUE if the SSC 'ssc' can match the empty string and any code
      * point; FALSE otherwise.  Thus, this is used to see if using 'ssc' buys
@@ -965,8 +967,8 @@ S_ssc_init(pTHX_ const RExC_state_t *pRExC_state, regnode_ssc *ssc)
 }
 
 STATIC int
-S_ssc_is_cp_posixl_init(pTHX_ const RExC_state_t *pRExC_state,
-                              const regnode_ssc *ssc)
+S_ssc_is_cp_posixl_init(const RExC_state_t *pRExC_state,
+                        const regnode_ssc *ssc)
 {
     /* Returns TRUE if the SSC 'ssc' is in its initial state with regard only
      * to the list of code points matched, and locale posix classes; hence does
@@ -1046,15 +1048,16 @@ S_get_ANYOF_cp_list_for_ssc(pTHX_ const RExC_state_t *pRExC_state,
         }
     }
 
-    /* An ANYOF node contains a bitmap for the first 256 code points, and an
-     * inversion list for the others, but if there are code points that should
-     * match only conditionally on the target string being UTF-8, those are
-     * placed in the inversion list, and not the bitmap.  Since there are
-     * circumstances under which they could match, they are included in the
-     * SSC.  But if the ANYOF node is to be inverted, we have to exclude them
-     * here, so that when we invert below, the end result actually does include
-     * them.  (Think about "\xe0" =~ /[^\xc0]/di;).  We have to do this here
-     * before we add the unconditionally matched code points */
+    /* An ANYOF node contains a bitmap for the first NUM_ANYOF_CODE_POINTS
+     * code points, and an inversion list for the others, but if there are code
+     * points that should match only conditionally on the target string being
+     * UTF-8, those are placed in the inversion list, and not the bitmap.
+     * Since there are circumstances under which they could match, they are
+     * included in the SSC.  But if the ANYOF node is to be inverted, we have
+     * to exclude them here, so that when we invert below, the end result
+     * actually does include them.  (Think about "\xe0" =~ /[^\xc0]/di;).  We
+     * have to do this here before we add the unconditionally matched code
+     * points */
     if (ANYOF_FLAGS(node) & ANYOF_INVERT) {
         _invlist_intersection_complement_2nd(invlist,
                                              PL_UpperLatin1,
@@ -1062,7 +1065,7 @@ S_get_ANYOF_cp_list_for_ssc(pTHX_ const RExC_state_t *pRExC_state,
     }
 
     /* Add in the points from the bit map */
-    for (i = 0; i < 256; i++) {
+    for (i = 0; i < NUM_ANYOF_CODE_POINTS; i++) {
         if (ANYOF_BITMAP_TEST(node, i)) {
             invlist = add_cp_to_invlist(invlist, i);
             new_node_has_latin1 = TRUE;
@@ -1410,10 +1413,9 @@ S_ssc_cp_and(pTHX_ regnode_ssc *ssc, const UV cp)
 }
 
 PERL_STATIC_INLINE void
-S_ssc_clear_locale(pTHX_ regnode_ssc *ssc)
+S_ssc_clear_locale(regnode_ssc *ssc)
 {
     /* Set the SSC 'ssc' to not match any locale things */
-
     PERL_ARGS_ASSERT_SSC_CLEAR_LOCALE;
 
     assert(is_ANYOF_SYNTHETIC(ssc));
@@ -1427,7 +1429,8 @@ S_ssc_finalize(pTHX_ RExC_state_t *pRExC_state, regnode_ssc *ssc)
 {
     /* The inversion list in the SSC is marked mortal; now we need a more
      * permanent copy, which is stored the same way that is done in a regular
-     * ANYOF node, with the first 256 code points in a bit map */
+     * ANYOF node, with the first NUM_ANYOF_CODE_POINTS code points in a bit
+     * map */
 
     SV* invlist = invlist_clone(ssc->invlist);
 
@@ -1718,7 +1721,7 @@ S_dump_trie_interim_table(pTHX_ const struct _reg_trie_data *trie,
               May be the same as tail.
   tail       : item following the branch sequence
   count      : words in the sequence
-  flags      : currently the OP() type we will be building one of /EXACT(|F|Fl)/
+  flags      : currently the OP() type we will be building one of /EXACT(|F|FA|FU|FU_SS)/
   depth      : indent depth
 
 Inplace optimizes a sequence of 2 or more Branch-Exact nodes into a TRIE node.
@@ -1947,7 +1950,6 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
                   regnode *first, regnode *last, regnode *tail,
                   U32 word_count, U32 flags, U32 depth)
 {
-    dVAR;
     /* first pass, loop through and scan words */
     reg_trie_data *trie;
     HV *widecharmap = NULL;
@@ -2007,6 +2009,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
     });
 
     re_trie_maxbuff = get_sv(RE_TRIE_MAXBUF_NAME, 1);
+    assert(re_trie_maxbuff);
     if (!SvIOK(re_trie_maxbuff)) {
         sv_setiv(re_trie_maxbuff, RE_TRIE_MAXBUF_INIT);
     }
@@ -2981,8 +2984,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
              : MADE_TRIE;
 }
 
-STATIC void
-S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode *stclass, U32 depth)
+STATIC regnode *
+S_construct_ahocorasick_from_trie(pTHX_ RExC_state_t *pRExC_state, regnode *source, U32 depth)
 {
 /* The Trie is constructed and compressed now so we can build a fail array if
  * it's needed
@@ -3020,13 +3023,27 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
     U32 *fail;
     reg_ac_data *aho;
     const U32 data_slot = add_data( pRExC_state, STR_WITH_LEN("T"));
+    regnode *stclass;
     GET_RE_DEBUG_FLAGS_DECL;
 
-    PERL_ARGS_ASSERT_MAKE_TRIE_FAILTABLE;
+    PERL_ARGS_ASSERT_CONSTRUCT_AHOCORASICK_FROM_TRIE;
+    PERL_UNUSED_CONTEXT;
 #ifndef DEBUGGING
     PERL_UNUSED_ARG(depth);
 #endif
 
+    if ( OP(source) == TRIE ) {
+        struct regnode_1 *op = (struct regnode_1 *)
+            PerlMemShared_calloc(1, sizeof(struct regnode_1));
+        StructCopy(source,op,struct regnode_1);
+        stclass = (regnode *)op;
+    } else {
+        struct regnode_charclass *op = (struct regnode_charclass *)
+            PerlMemShared_calloc(1, sizeof(struct regnode_charclass));
+        StructCopy(source,op,struct regnode_charclass);
+        stclass = (regnode *)op;
+    }
+    OP(stclass)+=2; /* covert the TRIE type to its AHO-CORASICK equivalent */
 
     ARG_SET( stclass, data_slot );
     aho = (reg_ac_data *) PerlMemShared_calloc( 1, sizeof(reg_ac_data) );
@@ -3093,6 +3110,7 @@ S_make_trie_failtable(pTHX_ RExC_state_t *pRExC_state, regnode *source,  regnode
     });
     Safefree(q);
     /*RExC_seen |= REG_TRIEDFA_SEEN;*/
+    return stclass;
 }
 
 
@@ -3416,9 +3434,9 @@ S_join_exact(pTHX_ RExC_state_t *pRExC_state, regnode *scan,
                 else { /* Here is a generic multi-char fold. */
                     U8* multi_end  = s + len;
 
-                    /* Count how many characters in it.  In the case of /aa, no
-                     * folds which contain ASCII code points are allowed, so
-                     * check for those, and skip if found. */
+                    /* Count how many characters are in it.  In the case of
+                     * /aa, no folds which contain ASCII code points are
+                     * allowed, so check for those, and skip if found. */
                     if (OP(scan) != EXACTFA && OP(scan) != EXACTFA_NO_TRIE) {
                         count = utf8_length(s, multi_end);
                         s = multi_end;
@@ -3577,7 +3595,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                        /* recursed: which subroutines have we recursed into */
                        /* and_withp: Valid if flags & SCF_DO_STCLASS_OR */
 {
-    dVAR;
     /* There must be at least this number of characters to match */
     SSize_t min = 0;
     I32 pars = 0, code;
@@ -4248,11 +4265,13 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            }
            flags &= ~SCF_DO_STCLASS;
        }
-       else if (PL_regkind[OP(scan)] == EXACT) { /* But OP != EXACT! */
+        else if (PL_regkind[OP(scan)] == EXACT) { /* But OP != EXACT!, so is
+                                                     EXACTFish */
            SSize_t l = STR_LEN(scan);
            UV uc = *((U8*)STRING(scan));
             SV* EXACTF_invlist = _new_invlist(4); /* Start out big enough for 2
                                                      separate code points */
+            const U8 * s = (U8*)STRING(scan);
 
            /* Search for fixed substrings supports EXACT only. */
            if (flags & SCF_DO_SUBSTR) {
@@ -4260,7 +4279,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                 scan_commit(pRExC_state, data, minlenp, is_inf);
            }
            if (UTF) {
-               const U8 * const s = (U8 *)STRING(scan);
                uc = utf8_to_uvchr_buf(s, s + l, NULL);
                l = utf8_length(s, s + l);
            }
@@ -4280,71 +4298,140 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                    data->longest = &(data->longest_float);
                }
            }
-            if (OP(scan) == EXACTFL) {
 
-                /* We don't know what the folds are; it could be anything. XXX
-                 * Actually, we only support UTF-8 encoding for code points
-                 * above Latin1, so we could know what those folds are. */
-                EXACTF_invlist = _add_range_to_invlist(EXACTF_invlist,
-                                                       0,
-                                                       UV_MAX);
+            if (OP(scan) != EXACTFL && flags & SCF_DO_STCLASS_AND) {
+                ssc_clear_locale(data->start_class);
             }
-            else {  /* Non-locale EXACTFish */
-                EXACTF_invlist = add_cp_to_invlist(EXACTF_invlist, uc);
-                if (flags & SCF_DO_STCLASS_AND) {
-                    ssc_clear_locale(data->start_class);
+
+            if (! UTF) {
+
+                /* We punt and assume can match anything if the node begins
+                 * with a multi-character fold.  Things are complicated.  For
+                 * example, /ffi/i could match any of:
+                 *  "\N{LATIN SMALL LIGATURE FFI}"
+                 *  "\N{LATIN SMALL LIGATURE FF}I"
+                 *  "F\N{LATIN SMALL LIGATURE FI}"
+                 *  plus several other things; and making sure we have all the
+                 *  possibilities is hard. */
+                if (is_MULTI_CHAR_FOLD_latin1_safe(s, s + STR_LEN(scan))) {
+                    EXACTF_invlist =
+                             _add_range_to_invlist(EXACTF_invlist, 0, UV_MAX);
                 }
-                if (uc < 256) { /* We know what the Latin1 folds are ... */
-                    if (IS_IN_SOME_FOLD_L1(uc)) {   /* For instance, we
-                                                       know if anything folds
-                                                       with this */
-                        EXACTF_invlist = add_cp_to_invlist(EXACTF_invlist,
+                else {
+
+                    /* Any Latin1 range character can potentially match any
+                     * other depending on the locale */
+                    if (OP(scan) == EXACTFL) {
+                        _invlist_union(EXACTF_invlist, PL_Latin1,
+                                                              &EXACTF_invlist);
+                    }
+                    else {
+                        /* But otherwise, it matches at least itself.  We can
+                         * quickly tell if it has a distinct fold, and if so,
+                         * it matches that as well */
+                        EXACTF_invlist = add_cp_to_invlist(EXACTF_invlist, uc);
+                        if (IS_IN_SOME_FOLD_L1(uc)) {
+                            EXACTF_invlist = add_cp_to_invlist(EXACTF_invlist,
                                                            PL_fold_latin1[uc]);
-                        if (OP(scan) != EXACTFA) { /* The folds below aren't
-                                                      legal under /iaa */
-                            if (isARG2_lower_or_UPPER_ARG1('s', uc)) {
-                                EXACTF_invlist
-                                    = add_cp_to_invlist(EXACTF_invlist,
-                                                LATIN_SMALL_LETTER_SHARP_S);
-                            }
-                            else if (uc == LATIN_SMALL_LETTER_SHARP_S) {
-                                EXACTF_invlist
-                                    = add_cp_to_invlist(EXACTF_invlist, 's');
-                                EXACTF_invlist
-                                    = add_cp_to_invlist(EXACTF_invlist, 'S');
-                            }
                         }
+                    }
 
-                        /* We also know if there are above-Latin1 code points
-                         * that fold to this (none legal for ASCII and /iaa) */
-                        if ((! isASCII(uc) || OP(scan) != EXACTFA)
-                            && HAS_NONLATIN1_FOLD_CLOSURE(uc))
-                        {
-                            /* XXX We could know exactly what does fold to this
-                             * if the reverse folds are loaded, as currently in
-                             * S_regclass() */
-                            _invlist_union(EXACTF_invlist,
-                                           PL_AboveLatin1,
-                                           &EXACTF_invlist);
+                    /* Some characters match above-Latin1 ones under /i.  This
+                     * is true of EXACTFL ones when the locale is UTF-8 */
+                    if (HAS_NONLATIN1_SIMPLE_FOLD_CLOSURE(uc)
+                        && (! isASCII(uc) || (OP(scan) != EXACTFA
+                                            && OP(scan) != EXACTFA_NO_TRIE)))
+                    {
+                        add_above_Latin1_folds(pRExC_state,
+                                               (U8) uc,
+                                               &EXACTF_invlist);
+                    }
+                }
+            }
+            else {  /* Pattern is UTF-8 */
+                U8 folded[UTF8_MAX_FOLD_CHAR_EXPAND * UTF8_MAXBYTES_CASE + 1] = { '\0' };
+                STRLEN foldlen = UTF8SKIP(s);
+                const U8* e = s + STR_LEN(scan);
+                SV** listp;
+
+                /* The only code points that aren't folded in a UTF EXACTFish
+                 * node are are the problematic ones in EXACTFL nodes */
+                if (OP(scan) == EXACTFL
+                    && is_PROBLEMATIC_LOCALE_FOLDEDS_START_cp(uc))
+                {
+                    /* We need to check for the possibility that this EXACTFL
+                     * node begins with a multi-char fold.  Therefore we fold
+                     * the first few characters of it so that we can make that
+                     * check */
+                    U8 *d = folded;
+                    int i;
+
+                    for (i = 0; i < UTF8_MAX_FOLD_CHAR_EXPAND && s < e; i++) {
+                        if (isASCII(*s)) {
+                            *(d++) = (U8) toFOLD(*s);
+                            s++;
+                        }
+                        else {
+                            STRLEN len;
+                            to_utf8_fold(s, d, &len);
+                            d += len;
+                            s += UTF8SKIP(s);
                         }
                     }
+
+                    /* And set up so the code below that looks in this folded
+                     * buffer instead of the node's string */
+                    e = d;
+                    foldlen = UTF8SKIP(folded);
+                    s = folded;
                 }
-                else {  /* Non-locale, above Latin1.  XXX We don't currently
-                           know what participates in folds with this, so have
-                           to assume anything could */
-
-                    /* XXX We could know exactly what does fold to this if the
-                     * reverse folds are loaded, as currently in S_regclass().
-                     * But we do know that under /iaa nothing in the ASCII
-                     * range can participate */
-                    if (OP(scan) == EXACTFA) {
-                        _invlist_union_complement_2nd(EXACTF_invlist,
-                                                      PL_XPosix_ptrs[_CC_ASCII],
-                                                      &EXACTF_invlist);
+
+                /* When we reach here 's' points to the fold of the first
+                 * character(s) of the node; and 'e' points to far enough along
+                 * the folded string to be just past any possible multi-char
+                 * fold. 'foldlen' is the length in bytes of the first
+                 * character in 's'
+                 *
+                 * Unlike the non-UTF-8 case, the macro for determining if a
+                 * string is a multi-char fold requires all the characters to
+                 * already be folded.  This is because of all the complications
+                 * if not.  Note that they are folded anyway, except in EXACTFL
+                 * nodes.  Like the non-UTF case above, we punt if the node
+                 * begins with a multi-char fold  */
+
+                if (is_MULTI_CHAR_FOLD_utf8_safe(s, e)) {
+                    EXACTF_invlist =
+                             _add_range_to_invlist(EXACTF_invlist, 0, UV_MAX);
+                }
+                else {  /* Single char fold */
+
+                    /* It matches all the things that fold to it, which are
+                     * found in PL_utf8_foldclosures (including itself) */
+                    EXACTF_invlist = add_cp_to_invlist(EXACTF_invlist, uc);
+                    if (! PL_utf8_foldclosures) {
+                        _load_PL_utf8_foldclosures();
                     }
-                    else {
-                        EXACTF_invlist = _add_range_to_invlist(EXACTF_invlist,
-                                                               0, UV_MAX);
+                    if ((listp = hv_fetch(PL_utf8_foldclosures,
+                                        (char *) s, foldlen, FALSE)))
+                    {
+                        AV* list = (AV*) *listp;
+                        IV k;
+                        for (k = 0; k <= av_tindex(list); k++) {
+                            SV** c_p = av_fetch(list, k, FALSE);
+                            UV c;
+                            assert(c_p);
+
+                            c = SvUV(*c_p);
+
+                            /* /aa doesn't allow folds between ASCII and non- */
+                            if ((OP(scan) == EXACTFA || OP(scan) == EXACTFA_NO_TRIE)
+                                && isASCII(c) != isASCII(uc))
+                            {
+                                continue;
+                            }
+
+                            EXACTF_invlist = add_cp_to_invlist(EXACTF_invlist, c);
+                        }
                     }
                 }
             }
@@ -4389,7 +4476,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                if (flags & SCF_DO_SUBSTR)
                    data->pos_min++;
                min++;
-               /* Fall through. */
+               /* FALLTHROUGH */
            case STAR:
                if (flags & SCF_DO_STCLASS) {
                    mincount = 0;
@@ -4692,13 +4779,13 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                    /* It is counted once already... */
                    data->pos_min += minnext * (mincount - counted);
 #if 0
-PerlIO_printf(Perl_debug_log, "counted=%"UVdf" deltanext=%"UVdf
-                              " SSize_t_MAX=%"UVdf" minnext=%"UVdf
-                              " maxcount=%"UVdf" mincount=%"UVdf"\n",
+PerlIO_printf(Perl_debug_log, "counted=%"UVuf" deltanext=%"UVuf
+                              " SSize_t_MAX=%"UVuf" minnext=%"UVuf
+                              " maxcount=%"UVuf" mincount=%"UVuf"\n",
     (UV)counted, (UV)deltanext, (UV)SSize_t_MAX, (UV)minnext, (UV)maxcount,
     (UV)mincount);
 if (deltanext != SSize_t_MAX)
-PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
+PerlIO_printf(Perl_debug_log, "LHS=%"UVuf" RHS=%"UVuf"\n",
     (UV)(-counted * deltanext + (minnext + deltanext) * maxcount
           - minnext * mincount), (UV)(SSize_t_MAX - data->pos_delta));
 #endif
@@ -4861,7 +4948,7 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
 
                case NPOSIXL:
                     invert = 1;
-                    /* FALL THROUGH */
+                    /* FALLTHROUGH */
 
                case POSIXL:
                     namedclass = classnum_to_namedclass(FLAGS(scan)) + invert;
@@ -4902,7 +4989,7 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
                 case NPOSIXA:   /* For these, we always know the exact set of
                                    what's matched */
                     invert = 1;
-                    /* FALL THROUGH */
+                    /* FALLTHROUGH */
                case POSIXA:
                     if (FLAGS(scan) == _CC_ASCII) {
                         my_invlist = PL_XPosix_ptrs[_CC_ASCII];
@@ -4917,7 +5004,7 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
                case NPOSIXD:
                case NPOSIXU:
                     invert = 1;
-                    /* FALL THROUGH */
+                    /* FALLTHROUGH */
                case POSIXD:
                case POSIXU:
                     my_invlist = invlist_clone(PL_XPosix_ptrs[FLAGS(scan)]);
@@ -4958,7 +5045,8 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
        else if (  PL_regkind[OP(scan)] == BRANCHJ
                 /* Lookbehind, or need to calculate parens/evals/stclass: */
                   && (scan->flags || data || (flags & SCF_DO_STCLASS))
-                  && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
+                  && (OP(scan) == IFMATCH || OP(scan) == UNLESSM))
+        {
             if ( OP(scan) == UNLESSM &&
                  scan->flags == 0 &&
                  OP(NEXTOPER(NEXTOPER(scan))) == NOTHING &&
@@ -5046,8 +5134,11 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
                         */
                        ssc_init(pRExC_state, data->start_class);
                    }  else {
-                       /* AND before and after: combine and continue */
+                        /* AND before and after: combine and continue.  These
+                         * assertions are zero-length, so can match an EMPTY
+                         * string */
                        ssc_and(pRExC_state, data->start_class, (regnode_charclass *) &intrnl);
+                        ANYOF_FLAGS(data->start_class) |= ANYOF_EMPTY_STRING;
                    }
                 }
            }
@@ -5119,6 +5210,7 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVdf" RHS=%"UVdf"\n",
 
                 if (f & SCF_DO_STCLASS_AND) {
                     ssc_and(pRExC_state, data->start_class, (regnode_charclass *) &intrnl);
+                    ANYOF_FLAGS(data->start_class) |= ANYOF_EMPTY_STRING;
                 }
                 if (data) {
                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
@@ -5429,12 +5521,12 @@ S_add_data(RExC_state_t* const pRExC_state, const char* const s, const U32 n)
     return count;
 }
 
-/*XXX: todo make this not included in a non debugging perl */
+/*XXX: todo make this not included in a non debugging perl, but appears to be
+ * used anyway there, in 'use re' */
 #ifndef PERL_IN_XSUB_RE
 void
 Perl_reginitcolors(pTHX)
 {
-    dVAR;
     const char * const s = PerlEnv_getenv("PERL_RE_COLORS");
     if (s) {
        char *t = savepv(s);
@@ -5488,8 +5580,6 @@ Perl_reginitcolors(pTHX)
 regexp_engine const *
 Perl_current_re_engine(pTHX)
 {
-    dVAR;
-
     if (IN_PERL_COMPILETIME) {
        HV * const table = GvHV(PL_hintgv);
        SV **ptr;
@@ -5516,7 +5606,6 @@ Perl_current_re_engine(pTHX)
 REGEXP *
 Perl_pregcomp(pTHX_ SV * const pattern, const U32 flags)
 {
-    dVAR;
     regexp_engine const *eng = current_re_engine();
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -5632,7 +5721,7 @@ S_concat_pat(pTHX_ RExC_state_t * const pRExC_state,
     /* if we know we have at least two args, create an empty string,
      * then concatenate args to that. For no args, return an empty string */
     if (!pat && pat_count != 1) {
-        pat = newSVpvn("", 0);
+        pat = newSVpvs("");
         SAVEFREESV(pat);
         alloced = TRUE;
     }
@@ -5668,7 +5757,7 @@ S_concat_pat(pTHX_ RExC_state_t * const pRExC_state,
             if (oplist) {
                 assert(oplist->op_type == OP_PADAV
                     || oplist->op_type == OP_RV2AV);
-                oplist = oplist->op_sibling;;
+                oplist = OP_SIBLING(oplist);
             }
 
             if (SvRMAGICAL(av)) {
@@ -5715,10 +5804,10 @@ S_concat_pat(pTHX_ RExC_state_t * const pRExC_state,
                 pRExC_state->code_blocks[n].src_regex = NULL;
                 n++;
                 code = 1;
-                oplist = oplist->op_sibling; /* skip CONST */
+                oplist = OP_SIBLING(oplist); /* skip CONST */
                 assert(oplist);
             }
-            oplist = oplist->op_sibling;;
+            oplist = OP_SIBLING(oplist);;
         }
 
        /* apply magic and QR overloading to arg */
@@ -5838,6 +5927,8 @@ S_has_runtime_code(pTHX_ RExC_state_t * const pRExC_state,
 {
     int n = 0;
     STRLEN s;
+    
+    PERL_UNUSED_CONTEXT;
 
     for (s = 0; s < plen; s++) {
        if (n < pRExC_state->num_code_blocks
@@ -6153,7 +6244,6 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                    OP *expr, const regexp_engine* eng, REGEXP *old_re,
                     bool *is_bare_re, U32 orig_rx_flags, U32 pm_flags)
 {
-    dVAR;
     REGEXP *rx;
     struct regexp *r;
     regexp_internal *ri;
@@ -6215,7 +6305,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
        OP *o;
        int ncode = 0;
 
-       for (o = cLISTOPx(expr)->op_first; o; o = o->op_sibling)
+       for (o = cLISTOPx(expr)->op_first; o; o = OP_SIBLING(o))
            if (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL))
                ncode++; /* count of DO blocks */
        if (ncode) {
@@ -6236,7 +6326,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
         if (expr->op_type == OP_CONST)
             n = 1;
         else
-            for (o = cLISTOPx(expr)->op_first; o; o = o->op_sibling) {
+            for (o = cLISTOPx(expr)->op_first; o; o = OP_SIBLING(o)) {
                 if (o->op_type == OP_CONST)
                     n++;
             }
@@ -6252,7 +6342,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
         if (expr->op_type == OP_CONST)
             new_patternp[n] = cSVOPx_sv(expr);
         else
-            for (o = cLISTOPx(expr)->op_first; o; o = o->op_sibling) {
+            for (o = cLISTOPx(expr)->op_first; o; o = OP_SIBLING(o)) {
                 if (o->op_type == OP_CONST)
                     new_patternp[n++] = cSVOPo_sv;
             }
@@ -6272,7 +6362,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
             assert(   expr->op_type == OP_PUSHMARK
                    || (expr->op_type == OP_NULL && expr->op_targ == OP_PUSHMARK)
                    || expr->op_type == OP_PADRANGE);
-            expr = expr->op_sibling;
+            expr = OP_SIBLING(expr);
     }
 
     pat = S_concat_pat(aTHX_ pRExC_state, NULL, new_patternp, pat_count,
@@ -6750,22 +6840,8 @@ reStudy:
        else if (PL_regkind[OP(first)] == TRIE &&
                ((reg_trie_data *)ri->data->data[ ARG(first) ])->minlen>0)
        {
-           regnode *trie_op;
-           /* this can happen only on restudy */
-           if ( OP(first) == TRIE ) {
-                struct regnode_1 *trieop = (struct regnode_1 *)
-                   PerlMemShared_calloc(1, sizeof(struct regnode_1));
-                StructCopy(first,trieop,struct regnode_1);
-                trie_op=(regnode *)trieop;
-            } else {
-                struct regnode_charclass *trieop = (struct regnode_charclass *)
-                   PerlMemShared_calloc(1, sizeof(struct regnode_charclass));
-                StructCopy(first,trieop,struct regnode_charclass);
-                trie_op=(regnode *)trieop;
-            }
-            OP(trie_op)+=2;
-            make_trie_failtable(pRExC_state, (regnode *)first, trie_op, 0);
-           ri->regstclass = trie_op;
+            /* this can happen only on restudy */
+            ri->regstclass = construct_ahocorasick_from_trie(pRExC_state, (regnode *)first, 0);
        }
 #endif
        else if (REGNODE_SIMPLE(OP(first)))
@@ -6788,6 +6864,7 @@ reStudy:
            goto again;
        }
        else if ((!sawopen || !RExC_sawback) &&
+            !sawlookahead &&
            (OP(first) == STAR &&
            PL_regkind[OP(NEXTOPER(first))] == REG_ANY) &&
             !(r->intflags & PREGf_ANCH) && !pRExC_state->num_code_blocks)
@@ -7758,7 +7835,7 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
 /* The header definitions are in F<inline_invlist.c> */
 
 PERL_STATIC_INLINE UV*
-S__invlist_array_init(pTHX_ SV* const invlist, const bool will_have_0)
+S__invlist_array_init(SV* const invlist, const bool will_have_0)
 {
     /* Returns a pointer to the first element in the inversion list's array.
      * This is called upon initialization of an inversion list.  Where the
@@ -7784,7 +7861,7 @@ S__invlist_array_init(pTHX_ SV* const invlist, const bool will_have_0)
 }
 
 PERL_STATIC_INLINE UV*
-S_invlist_array(pTHX_ SV* const invlist)
+S_invlist_array(SV* const invlist)
 {
     /* Returns the pointer to the inversion list's array.  Every time the
      * length changes, this needs to be called in case malloc or realloc moved
@@ -7809,7 +7886,7 @@ S_invlist_set_len(pTHX_ SV* const invlist, const UV len, const bool offset)
 {
     /* Sets the current number of elements stored in the inversion list.
      * Updates SvCUR correspondingly */
-
+    PERL_UNUSED_CONTEXT;
     PERL_ARGS_ASSERT_INVLIST_SET_LEN;
 
     assert(SvTYPE(invlist) == SVt_INVLIST);
@@ -7822,11 +7899,10 @@ S_invlist_set_len(pTHX_ SV* const invlist, const UV len, const bool offset)
 }
 
 PERL_STATIC_INLINE IV*
-S_get_invlist_previous_index_addr(pTHX_ SV* invlist)
+S_get_invlist_previous_index_addr(SV* invlist)
 {
     /* Return the address of the IV that is reserved to hold the cached index
      * */
-
     PERL_ARGS_ASSERT_GET_INVLIST_PREVIOUS_INDEX_ADDR;
 
     assert(SvTYPE(invlist) == SVt_INVLIST);
@@ -7835,7 +7911,7 @@ S_get_invlist_previous_index_addr(pTHX_ SV* invlist)
 }
 
 PERL_STATIC_INLINE IV
-S_invlist_previous_index(pTHX_ SV* const invlist)
+S_invlist_previous_index(SV* const invlist)
 {
     /* Returns cached index of previous search */
 
@@ -7845,7 +7921,7 @@ S_invlist_previous_index(pTHX_ SV* const invlist)
 }
 
 PERL_STATIC_INLINE void
-S_invlist_set_previous_index(pTHX_ SV* const invlist, const IV index)
+S_invlist_set_previous_index(SV* const invlist, const IV index)
 {
     /* Caches <index> for later retrieval */
 
@@ -7857,7 +7933,7 @@ S_invlist_set_previous_index(pTHX_ SV* const invlist, const IV index)
 }
 
 PERL_STATIC_INLINE UV
-S_invlist_max(pTHX_ SV* const invlist)
+S_invlist_max(SV* const invlist)
 {
     /* Returns the maximum number of elements storable in the inversion list's
      * array, without having to realloc() */
@@ -7976,7 +8052,7 @@ S_invlist_extend(pTHX_ SV* const invlist, const UV new_max)
 }
 
 PERL_STATIC_INLINE void
-S_invlist_trim(pTHX_ SV* const invlist)
+S_invlist_trim(SV* const invlist)
 {
     PERL_ARGS_ASSERT_INVLIST_TRIM;
 
@@ -8075,7 +8151,7 @@ S__append_range_to_invlist(pTHX_ SV* const invlist,
 #ifndef PERL_IN_XSUB_RE
 
 IV
-Perl__invlist_search(pTHX_ SV* const invlist, const UV cp)
+Perl__invlist_search(SV* const invlist, const UV cp)
 {
     /* Searches the inversion list for the entry that contains the input code
      * point <cp>.  If <cp> is not in the list, -1 is returned.  Otherwise, the
@@ -8163,8 +8239,8 @@ Perl__invlist_search(pTHX_ SV* const invlist, const UV cp)
 }
 
 void
-Perl__invlist_populate_swatch(pTHX_ SV* const invlist,
-                                    const UV start, const UV end, U8* swatch)
+Perl__invlist_populate_swatch(SV* const invlist,
+                              const UV start, const UV end, U8* swatch)
 {
     /* populates a swatch of a swash the same way swatch_get() does in utf8.c,
      * but is used when the swash has an inversion list.  This makes this much
@@ -8876,7 +8952,7 @@ S_invlist_clone(pTHX_ SV* const invlist)
 }
 
 PERL_STATIC_INLINE STRLEN*
-S_get_invlist_iter_addr(pTHX_ SV* invlist)
+S_get_invlist_iter_addr(SV* invlist)
 {
     /* Return the address of the UV that contains the current iteration
      * position */
@@ -8889,7 +8965,7 @@ S_get_invlist_iter_addr(pTHX_ SV* invlist)
 }
 
 PERL_STATIC_INLINE void
-S_invlist_iterinit(pTHX_ SV* invlist)  /* Initialize iterator for invlist */
+S_invlist_iterinit(SV* invlist)        /* Initialize iterator for invlist */
 {
     PERL_ARGS_ASSERT_INVLIST_ITERINIT;
 
@@ -8897,7 +8973,7 @@ S_invlist_iterinit(pTHX_ SV* invlist)     /* Initialize iterator for invlist */
 }
 
 PERL_STATIC_INLINE void
-S_invlist_iterfinish(pTHX_ SV* invlist)
+S_invlist_iterfinish(SV* invlist)
 {
     /* Terminate iterator for invlist.  This is to catch development errors.
      * Any iteration that is interrupted before completed should call this
@@ -8913,7 +8989,7 @@ S_invlist_iterfinish(pTHX_ SV* invlist)
 }
 
 STATIC bool
-S_invlist_iternext(pTHX_ SV* invlist, UV* start, UV* end)
+S_invlist_iternext(SV* invlist, UV* start, UV* end)
 {
     /* An C<invlist_iterinit> call on <invlist> must be used to set this up.
      * This call sets in <*start> and <*end>, the next range in <invlist>.
@@ -8948,7 +9024,7 @@ S_invlist_iternext(pTHX_ SV* invlist, UV* start, UV* end)
 }
 
 PERL_STATIC_INLINE bool
-S_invlist_is_iterating(pTHX_ SV* const invlist)
+S_invlist_is_iterating(SV* const invlist)
 {
     PERL_ARGS_ASSERT_INVLIST_IS_ITERATING;
 
@@ -8956,7 +9032,7 @@ S_invlist_is_iterating(pTHX_ SV* const invlist)
 }
 
 PERL_STATIC_INLINE UV
-S_invlist_highest(pTHX_ SV* const invlist)
+S_invlist_highest(SV* const invlist)
 {
     /* Returns the highest code point that matches an inversion list.  This API
      * has an ambiguity, as it returns 0 under either the highest is actually
@@ -9068,6 +9144,23 @@ Perl__invlist_dump(pTHX_ PerlIO *file, I32 level,
         count += 2;
     }
 }
+
+void
+Perl__load_PL_utf8_foldclosures (pTHX)
+{
+    assert(! PL_utf8_foldclosures);
+
+    /* If the folds haven't been read in, call a fold function
+     * to force that */
+    if (! PL_utf8_tofold) {
+        U8 dummy[UTF8_MAXBYTES_CASE+1];
+
+        /* This string is just a short named one above \xff */
+        to_utf8_fold((U8*) HYPHEN_UTF8, dummy, NULL);
+        assert(PL_utf8_tofold); /* Verify that worked */
+    }
+    PL_utf8_foldclosures = _swash_inversion_hash(PL_utf8_tofold);
+}
 #endif
 
 #ifdef PERL_ARGS_ASSERT__INVLISTEQ
@@ -9369,7 +9462,6 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
      * RExC_parse beyond the '('.  Things like '(?' are indivisible tokens, and
      * this flag alerts us to the need to check for that */
 {
-    dVAR;
     regnode *ret;              /* Will be the head of the group. */
     regnode *br;
     regnode *lastbr;
@@ -9381,6 +9473,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
     bool is_open = 0;
     I32 freeze_paren = 0;
     I32 after_freeze = 0;
+    I32 num; /* numeric backreferences */
 
     char * parse_start = RExC_parse; /* MJD */
     char * const oregcomp_parse = RExC_parse;
@@ -9411,8 +9504,9 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
             int internal_argval = 0; /* internal_argval is only useful if
                                         !argok */
 
-            if (has_intervening_patws && SIZE_ONLY) {
-                ckWARNregdep(RExC_parse + 1, "In '(*VERB...)', splitting the initial '(*' is deprecated");
+            if (has_intervening_patws) {
+                RExC_parse++;
+                vFAIL("In '(*VERB...)', the '(' and '*' must be adjacent");
             }
            while ( *RExC_parse && *RExC_parse != ')' ) {
                if ( *RExC_parse == ':' ) {
@@ -9518,8 +9612,10 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
         else if (*RExC_parse == '?') { /* (?...) */
            bool is_logical = 0;
            const char * const seqstart = RExC_parse;
-            if (has_intervening_patws && SIZE_ONLY) {
-                ckWARNregdep(RExC_parse + 1, "In '(?...)', splitting the initial '(?' is deprecated");
+            const char * endptr;
+            if (has_intervening_patws) {
+                RExC_parse++;
+                vFAIL("In '(?...)', the '(' and '?' must be adjacent");
             }
 
            RExC_parse++;
@@ -9661,6 +9757,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                 RExC_seen |= REG_LOOKBEHIND_SEEN;
                RExC_in_lookbehind++;
                RExC_parse++;
+                /* FALLTHROUGH */
            case '=':           /* (?=...) */
                RExC_seen_zerolen++;
                 break;
@@ -9685,18 +9782,6 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
            case '@':           /* (?@...) */
                vFAIL2("Sequence (?%c...) not implemented", (int)paren);
                break;
-            case '#':           /* (?#...) */
-                /* XXX As soon as we disallow separating the '?' and '*' (by
-                 * spaces or (?#...) comment), it is believed that this case
-                 * will be unreachable and can be removed.  See
-                 * [perl #117327] */
-                while (*RExC_parse && *RExC_parse != ')')
-                   RExC_parse++;
-               if (*RExC_parse != ')')
-                   FAIL("Sequence (?#... not terminated");
-               nextchar(pRExC_state);
-               *flagp = TRYAGAIN;
-               return NULL;
            case '0' :           /* (?0) */
            case 'R' :           /* (?R) */
                if (*RExC_parse != ')')
@@ -9707,8 +9792,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                nextchar(pRExC_state);
                return ret;
                /*notreached*/
-            { /* named and numeric backreferences */
-                I32 num;
+            /* named and numeric backreferences */
             case '&':            /* (?&NAME) */
                 parse_start = RExC_parse - 1;
               named_recursion:
@@ -9733,17 +9817,26 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                     RExC_parse--; /* rewind to let it be handled later */
                     goto parse_flags;
                 }
-                /*FALLTHROUGH */
+                /* FALLTHROUGH */
             case '1': case '2': case '3': case '4': /* (?1) */
            case '5': case '6': case '7': case '8': case '9':
                RExC_parse--;
               parse_recursion:
-               num = atoi(RExC_parse);
-               parse_start = RExC_parse - 1; /* MJD */
-               if (*RExC_parse == '-')
-                   RExC_parse++;
-               while (isDIGIT(*RExC_parse))
-                       RExC_parse++;
+                {
+                    bool is_neg = FALSE;
+                    parse_start = RExC_parse - 1; /* MJD */
+                    if (*RExC_parse == '-') {
+                        RExC_parse++;
+                        is_neg = TRUE;
+                    }
+                    num = grok_atou(RExC_parse, &endptr);
+                    if (endptr)
+                       RExC_parse = (char*)endptr;
+                    if (is_neg) {
+                        /* Some limit for num? */
+                        num = -num;
+                    }
+                }
                if (*RExC_parse!=')')
                    vFAIL("Expecting close bracket");
 
@@ -9790,7 +9883,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                 *flagp |= POSTPONED;
                 nextchar(pRExC_state);
                 return ret;
-            } /* named and numeric backreferences */
+
             assert(0); /* NOT REACHED */
 
            case '?':           /* (??...) */
@@ -9805,7 +9898,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                }
                *flagp |= POSTPONED;
                paren = *RExC_parse++;
-               /* FALL THROUGH */
+               /* FALLTHROUGH */
            case '{':           /* (?{...}) */
            {
                U32 n = 0;
@@ -9883,6 +9976,8 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                         REGTAIL(pRExC_state, ret, tail);
                        goto insert_if;
                    }
+                   /* Fall through to â€˜Unknown switch condition’ at the
+                      end of the if/else chain. */
                }
                else if ( RExC_parse[0] == '<'     /* (?(<NAME>)...) */
                         || RExC_parse[0] == '\'' ) /* (?('NAME')...) */
@@ -9920,9 +10015,9 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                    RExC_parse++;
                    parno = 0;
                    if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
-                       parno = atoi(RExC_parse++);
-                       while (isDIGIT(*RExC_parse))
-                           RExC_parse++;
+                       parno = grok_atou(RExC_parse, &endptr);
+                       if (endptr)
+                            RExC_parse = (char*)endptr;
                    } else if (RExC_parse[0] == '&') {
                        SV *sv_dat;
                        RExC_parse++;
@@ -9939,10 +10034,9 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                     /* (?(1)...) */
                    char c;
                    char *tmp;
-                   parno = atoi(RExC_parse++);
-
-                   while (isDIGIT(*RExC_parse))
-                       RExC_parse++;
+                   parno = grok_atou(RExC_parse, &endptr);
+                    if (endptr)
+                       RExC_parse = (char*)endptr;
                     ret = reganode(pRExC_state, GROUPP, parno);
 
                  insert_if_check_paren:
@@ -10007,10 +10101,8 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                                     but I can't figure out why. -- dmq*/
                    return ret;
                }
-               else {
-                    RExC_parse += UTF ? UTF8SKIP(RExC_parse) : 1;
-                    vFAIL("Unknown switch condition (?(...))");
-               }
+                RExC_parse += UTF ? UTF8SKIP(RExC_parse) : 1;
+                vFAIL("Unknown switch condition (?(...))");
            }
            case '[':           /* (?[ ... ]) */
                 return handle_regex_sets(pRExC_state, NULL, flagp, depth,
@@ -10150,7 +10242,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
        case '=':
        case '!':
            *flagp &= ~HASWIDTH;
-           /* FALL THROUGH */
+           /* FALLTHROUGH */
        case '>':
            ender = reg_node(pRExC_state, SUCCEED);
            break;
@@ -10287,7 +10379,6 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
 STATIC regnode *
 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first, U32 depth)
 {
-    dVAR;
     regnode *ret;
     regnode *chain = NULL;
     regnode *latest;
@@ -10369,7 +10460,6 @@ S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first, U32 depth)
 STATIC regnode *
 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
 {
-    dVAR;
     regnode *ret;
     char op;
     char *next;
@@ -10402,7 +10492,7 @@ S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
 
     op = *RExC_parse;
 
-    if (op == '{' && regcurly(RExC_parse, FALSE)) {
+    if (op == '{' && regcurly(RExC_parse)) {
        maxpos = NULL;
 #ifdef RE_TRACK_PATTERN_OFFSETS
         parse_start = RExC_parse; /* MJD */
@@ -10418,15 +10508,16 @@ S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
            next++;
        }
        if (*next == '}') {             /* got one */
+            const char* endptr;
            if (!maxpos)
                maxpos = next;
            RExC_parse++;
-           min = atoi(RExC_parse);
+           min = grok_atou(RExC_parse, &endptr);
            if (*maxpos == ',')
                maxpos++;
            else
                maxpos = RExC_parse;
-           max = atoi(maxpos);
+           max = grok_atou(maxpos, &endptr);
            if (!max && *maxpos != '0')
                max = REG_INFTY;                /* meaning "infinity" */
            else if (max >= REG_INFTY)
@@ -10672,12 +10763,13 @@ S_grok_bslash_N(pTHX_ RExC_state_t *pRExC_state, regnode** node_p,
      * modifier.  The other meaning does not, so use a temporary until we find
      * out which we are being called with */
     p = (RExC_flags & RXf_PMf_EXTENDED)
-       ? regwhite( pRExC_state, RExC_parse )
+       ? regpatws(pRExC_state, RExC_parse,
+                                TRUE) /* means recognize comments */
        : RExC_parse;
 
     /* Disambiguate between \N meaning a named character versus \N meaning
      * [^\n].  The former is assumed when it can't be the latter. */
-    if (*p != '{' || regcurly(p, FALSE)) {
+    if (*p != '{' || regcurly(p)) {
        RExC_parse = p;
        if (! node_p) {
            /* no bare \N allowed in a charclass */
@@ -10899,7 +10991,7 @@ S_reg_recode(pTHX_ const char value, SV **encp)
 }
 
 PERL_STATIC_INLINE U8
-S_compute_EXACTish(pTHX_ RExC_state_t *pRExC_state)
+S_compute_EXACTish(RExC_state_t *pRExC_state)
 {
     U8 op;
 
@@ -11072,18 +11164,17 @@ S_alloc_maybe_populate_EXACT(pTHX_ RExC_state_t *pRExC_state,
 }
 
 
-/* return atoi(p), unless it's too big to sensibly be a backref,
+/* Parse backref decimal value, unless it's too big to sensibly be a backref,
  * in which case return I32_MAX (rather than possibly 32-bit wrapping) */
 
 static I32
 S_backref_value(char *p)
 {
-    char *q = p;
-
-    for (;isDIGIT(*q); q++); /* calculate length of num */
-    if (q - p == 0 || q - p > 9)
+    const char* endptr;
+    UV val = grok_atou(p, &endptr);
+    if (endptr == p || endptr == NULL || val > I32_MAX)
         return I32_MAX;
-    return atoi(p);
+    return (I32)val;
 }
 
 
@@ -11156,12 +11247,12 @@ S_backref_value(char *p)
 STATIC regnode *
 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
 {
-    dVAR;
     regnode *ret = NULL;
     I32 flags = 0;
     char *parse_start = RExC_parse;
     U8 op;
     int invert = 0;
+    U8 arg;
 
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -11258,12 +11349,6 @@ tryagain:
        vFAIL("Internal urp");
                                /* Supposed to be caught earlier. */
        break;
-    case '{':
-       if (!regcurly(RExC_parse, FALSE)) {
-           RExC_parse++;
-           goto defchar;
-       }
-       /* FALL THROUGH */
     case '?':
     case '+':
     case '*':
@@ -11284,7 +11369,6 @@ tryagain:
           literal text handling code.
        */
        switch ((U8)*++RExC_parse) {
-            U8 arg;
        /* Special Escapes */
        case 'A':
            RExC_seen_zerolen++;
@@ -11320,6 +11404,9 @@ tryagain:
            ret = reg_node(pRExC_state, CANY);
             RExC_seen |= REG_CANY_SEEN;
            *flagp |= HASWIDTH|SIMPLE;
+            if (SIZE_ONLY) {
+                ckWARNdep(RExC_parse+1, "\\C is deprecated");
+            }
            goto finish_meta_pat;
        case 'X':
            ret = reg_node(pRExC_state, CLUMP);
@@ -11426,7 +11513,7 @@ tryagain:
             }
 
            *flagp |= HASWIDTH|SIMPLE;
-            /* FALL THROUGH */
+            /* FALLTHROUGH */
 
          finish_meta_pat:
            nextchar(pRExC_state);
@@ -11625,7 +11712,7 @@ tryagain:
        case '\0':
            if (RExC_parse >= RExC_end)
                FAIL("Trailing \\");
-           /* FALL THROUGH */
+           /* FALLTHROUGH */
        default:
            /* Do not generate "unrecognized" warnings here, we fall
               back into the quick-grab loop below */
@@ -11636,10 +11723,11 @@ tryagain:
 
     case '#':
        if (RExC_flags & RXf_PMf_EXTENDED) {
-           if ( reg_skipcomment( pRExC_state ) )
+           RExC_parse = reg_skipcomment( pRExC_state, RExC_parse );
+           if (RExC_parse < RExC_end)
                goto tryagain;
        }
-       /* FALL THROUGH */
+       /* FALLTHROUGH */
 
     default:
 
@@ -11717,7 +11805,8 @@ tryagain:
                oldp = p;
 
                if (RExC_flags & RXf_PMf_EXTENDED)
-                   p = regwhite( pRExC_state, p );
+                    p = regpatws(pRExC_state, p,
+                                          TRUE); /* means recognize comments */
                switch ((U8)*p) {
                case '^':
                case '$':
@@ -11800,7 +11889,7 @@ tryagain:
                        p++;
                        break;
                    case 'e':
-                         ender = ASCII_TO_NATIVE('\033');
+                       ender = ESC_NATIVE;
                        p++;
                        break;
                    case 'a':
@@ -11896,6 +11985,7 @@ tryagain:
                             --p;
                             goto loopdone;
                         }
+                        /* FALLTHROUGH */
                     case '0':
                        {
                            I32 flags = PERL_SCAN_SILENT_ILLDIGIT;
@@ -11930,7 +12020,7 @@ tryagain:
                    case '\0':
                        if (p >= RExC_end)
                            FAIL("Trailing \\");
-                       /* FALL THROUGH */
+                       /* FALLTHROUGH */
                    default:
                        if (!SIZE_ONLY&& isALPHANUMERIC(*p)) {
                            /* Include any { following the alpha to emphasize
@@ -11942,17 +12032,18 @@ tryagain:
                        goto normal_default;
                    } /* End of switch on '\' */
                    break;
+               case '{':
+                   /* Currently we don't warn when the lbrace is at the start
+                    * of a construct.  This catches it in the middle of a
+                    * literal string, or when its the first thing after
+                    * something like "\b" */
+                   if (! SIZE_ONLY
+                       && (len || (p > RExC_start && isALPHA_A(*(p -1)))))
+                   {
+                       ckWARNregdep(p + 1, "Unescaped left brace in regex is deprecated, passed through");
+                   }
+                   /*FALLTHROUGH*/
                default:    /* A literal character */
-
-                    if (! SIZE_ONLY
-                        && RExC_flags & RXf_PMf_EXTENDED
-                        && ckWARN_d(WARN_DEPRECATED)
-                        && is_PATWS_non_low_safe(p, RExC_end, UTF))
-                    {
-                        vWARN_dep(p + ((UTF) ? UTF8SKIP(p) : 1),
-                                "Escape literal pattern white space under /x");
-                    }
-
                  normal_default:
                    if (UTF8_IS_START(*p) && UTF) {
                        STRLEN numlen;
@@ -11970,7 +12061,8 @@ tryagain:
                 */
 
                if ( RExC_flags & RXf_PMf_EXTENDED)
-                   p = regwhite( pRExC_state, p );
+                    p = regpatws(pRExC_state, p,
+                                          TRUE); /* means recognize comments */
 
                 /* If the next thing is a quantifier, it applies to this
                  * character only, which means that this character has to be in
@@ -12325,39 +12417,11 @@ tryagain:
 }
 
 STATIC char *
-S_regwhite( RExC_state_t *pRExC_state, char *p )
-{
-    const char *e = RExC_end;
-
-    PERL_ARGS_ASSERT_REGWHITE;
-
-    while (p < e) {
-       if (isSPACE(*p))
-           ++p;
-       else if (*p == '#') {
-            bool ended = 0;
-           do {
-               if (*p++ == '\n') {
-                   ended = 1;
-                   break;
-               }
-           } while (p < e);
-           if (!ended)
-                RExC_seen |= REG_RUN_ON_COMMENT_SEEN;
-       }
-       else
-           break;
-    }
-    return p;
-}
-
-STATIC char *
-S_regpatws( RExC_state_t *pRExC_state, char *p , const bool recognize_comment )
+S_regpatws(RExC_state_t *pRExC_state, char *p , const bool recognize_comment )
 {
     /* Returns the next non-pattern-white space, non-comment character (the
      * latter only if 'recognize_comment is true) in the string p, which is
-     * ended by RExC_end.  If there is no line break ending a comment,
-     * RExC_seen has added the REG_RUN_ON_COMMENT_SEEN flag; */
+     * ended by RExC_end.  See also reg_skipcomment */
     const char *e = RExC_end;
 
     PERL_ARGS_ASSERT_REGPATWS;
@@ -12368,16 +12432,7 @@ S_regpatws( RExC_state_t *pRExC_state, char *p , const bool recognize_comment )
            p += len;
         }
        else if (recognize_comment && *p == '#') {
-            bool ended = 0;
-           do {
-                p++;
-                if (is_LNBREAK_safe(p, e, UTF)) {
-                   ended = 1;
-                   break;
-               }
-           } while (p < e);
-           if (!ended)
-                RExC_seen |= REG_RUN_ON_COMMENT_SEEN;
+            p = reg_skipcomment(pRExC_state, p);
        }
        else
            break;
@@ -12417,14 +12472,16 @@ S_populate_ANYOF_from_invlist(pTHX_ regnode *node, SV** invlist_ptr)
             }
 
            /* Quit if are above what we should change */
-           if (start > 255) {
+           if (start >= NUM_ANYOF_CODE_POINTS) {
                break;
            }
 
            change_invlist = TRUE;
 
            /* Set all the bits in the range, up to the max that we are doing */
-           high = (end < 255) ? end : 255;
+           high = (end < NUM_ANYOF_CODE_POINTS - 1)
+                   ? end
+                   : NUM_ANYOF_CODE_POINTS - 1;
            for (i = start; i <= (int) high; i++) {
                if (! ANYOF_BITMAP_TEST(node, i)) {
                    ANYOF_BITMAP_SET(node, i);
@@ -12464,7 +12521,6 @@ S_populate_ANYOF_from_invlist(pTHX_ regnode *node, SV** invlist_ptr)
 PERL_STATIC_INLINE I32
 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value, const bool strict)
 {
-    dVAR;
     I32 namedclass = OOB_NAMEDCLASS;
 
     PERL_ARGS_ASSERT_REGPPOSIXCC;
@@ -12606,7 +12662,7 @@ S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value, const bool strict)
 }
 
 STATIC bool
-S_could_it_be_a_POSIX_class(pTHX_ RExC_state_t *pRExC_state)
+S_could_it_be_a_POSIX_class(RExC_state_t *pRExC_state)
 {
     /* This applies some heuristics at the current parse position (which should
      * be at a '[') to see if what follows might be intended to be a [:posix:]
@@ -12705,11 +12761,11 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
         while (RExC_parse < RExC_end) {
             SV* current = NULL;
             RExC_parse = regpatws(pRExC_state, RExC_parse,
-                                TRUE); /* means recognize comments */
+                                          TRUE); /* means recognize comments */
             switch (*RExC_parse) {
                 case '?':
                     if (RExC_parse[1] == '[') depth++, RExC_parse++;
-                    /* FALL THROUGH */
+                    /* FALLTHROUGH */
                 default:
                     break;
                 case '\\':
@@ -12822,7 +12878,7 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
 
         /* Skip white space */
         RExC_parse = regpatws(pRExC_state, RExC_parse,
-                                TRUE); /* means recognize comments */
+                                         TRUE /* means recognize comments */ );
         if (RExC_parse >= RExC_end) {
             Perl_croak(aTHX_ "panic: Read past end of '(?[ ])'");
         }
@@ -12896,7 +12952,7 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
                     RExC_flags = save_flags;
                     goto handle_operand;
                 }
-                /* FALL THROUGH */
+                /* FALLTHROUGH */
 
             default:
                 RExC_parse += (UTF) ? UTF8SKIP(RExC_parse) : 1;
@@ -12992,7 +13048,7 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
                 top_index -= 2;
                 SvREFCNT_dec_NN(lparen);
 
-                /* FALL THROUGH */
+                /* FALLTHROUGH */
             }
 
               handle_operand:
@@ -13151,6 +13207,61 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
 }
 #undef IS_OPERAND
 
+STATIC void
+S_add_above_Latin1_folds(pTHX_ RExC_state_t *pRExC_state, const U8 cp, SV** invlist)
+{
+    /* This hard-codes the Latin1/above-Latin1 folding rules, so that an
+     * innocent-looking character class, like /[ks]/i won't have to go out to
+     * disk to find the possible matches.
+     *
+     * This should be called only for a Latin1-range code points, cp, which is
+     * known to be involved in a simple fold with other code points above
+     * Latin1.  It would give false results if /aa has been specified.
+     * Multi-char folds are outside the scope of this, and must be handled
+     * specially.
+     *
+     * XXX It would be better to generate these via regen, in case a new
+     * version of the Unicode standard adds new mappings, though that is not
+     * really likely, and may be caught by the default: case of the switch
+     * below. */
+
+    PERL_ARGS_ASSERT_ADD_ABOVE_LATIN1_FOLDS;
+
+    assert(HAS_NONLATIN1_SIMPLE_FOLD_CLOSURE(cp));
+
+    switch (cp) {
+        case 'k':
+        case 'K':
+          *invlist =
+             add_cp_to_invlist(*invlist, KELVIN_SIGN);
+            break;
+        case 's':
+        case 'S':
+          *invlist = add_cp_to_invlist(*invlist, LATIN_SMALL_LETTER_LONG_S);
+            break;
+        case MICRO_SIGN:
+          *invlist = add_cp_to_invlist(*invlist, GREEK_CAPITAL_LETTER_MU);
+          *invlist = add_cp_to_invlist(*invlist, GREEK_SMALL_LETTER_MU);
+            break;
+        case LATIN_CAPITAL_LETTER_A_WITH_RING_ABOVE:
+        case LATIN_SMALL_LETTER_A_WITH_RING_ABOVE:
+          *invlist = add_cp_to_invlist(*invlist, ANGSTROM_SIGN);
+            break;
+        case LATIN_SMALL_LETTER_Y_WITH_DIAERESIS:
+          *invlist = add_cp_to_invlist(*invlist,
+                                        LATIN_CAPITAL_LETTER_Y_WITH_DIAERESIS);
+            break;
+        case LATIN_SMALL_LETTER_SHARP_S:
+          *invlist = add_cp_to_invlist(*invlist, LATIN_CAPITAL_LETTER_SHARP_S);
+            break;
+        default:
+            /* Use deprecated warning to increase the chances of this being
+             * output */
+            ckWARN2reg_d(RExC_parse, "Perl folding rules are not up-to-date for 0x%02X; please use the perlbug utility to report;", cp);
+            break;
+    }
+}
+
 /* The names of properties whose definitions are not known at compile time are
  * stored in this SV, after a constant heading.  So if the length has been
  * changed since initialization, then there is a run-time definition. */
@@ -13182,17 +13293,16 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
      * ignored in the recursion by means of a flag:
      * <RExC_in_multi_char_class>.)
      *
-     * ANYOF nodes contain a bit map for the first 256 characters, with the
-     * corresponding bit set if that character is in the list.  For characters
-     * above 255, a range list or swash is used.  There are extra bits for \w,
-     * etc. in locale ANYOFs, as what these match is not determinable at
-     * compile time
+     * ANYOF nodes contain a bit map for the first NUM_ANYOF_CODE_POINTS
+     * characters, with the corresponding bit set if that character is in the
+     * list.  For characters above this, a range list or swash is used.  There
+     * are extra bits for \w, etc. in locale ANYOFs, as what these match is not
+     * determinable at compile time
      *
      * Returns NULL, setting *flagp to RESTART_UTF8 if the sizing scan needs
      * to be restarted.  This can only happen if ret_invlist is non-NULL.
      */
 
-    dVAR;
     UV prevvalue = OOB_UNICODE, save_prevvalue = OOB_UNICODE;
     IV range = 0;
     UV value = OOB_UNICODE, save_value = OOB_UNICODE;
@@ -13294,7 +13404,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
 
     if (skip_white) {
         RExC_parse = regpatws(pRExC_state, RExC_parse,
-                              FALSE /* means don't recognize comments */);
+                              FALSE /* means don't recognize comments */ );
     }
 
     if (UCHARAT(RExC_parse) == '^') {  /* Complement of range. */
@@ -13304,7 +13414,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
         RExC_naughty++;
         if (skip_white) {
             RExC_parse = regpatws(pRExC_state, RExC_parse,
-                                  FALSE /* means don't recognize comments */);
+                                  FALSE /* means don't recognize comments */ );
         }
     }
 
@@ -13342,7 +13452,7 @@ parseit:
 
         if (skip_white) {
             RExC_parse = regpatws(pRExC_state, RExC_parse,
-                                  FALSE /* means don't recognize comments */);
+                                  FALSE /* means don't recognize comments */ );
         }
 
         if  (UCHARAT(RExC_parse) == ']') {
@@ -13443,12 +13553,12 @@ parseit:
                    e = strchr(RExC_parse++, '}');
                     if (!e)
                         vFAIL2("Missing right brace on \\%c{}", c);
-                   while (isSPACE(UCHARAT(RExC_parse)))
+                   while (isSPACE(*RExC_parse))
                        RExC_parse++;
                     if (e == RExC_parse)
                         vFAIL2("Empty \\%c{}", c);
                    n = e - RExC_parse;
-                   while (isSPACE(UCHARAT(RExC_parse + n - 1)))
+                   while (isSPACE(*(RExC_parse + n - 1)))
                        n--;
                }
                else {
@@ -13457,7 +13567,6 @@ parseit:
                }
                if (!SIZE_ONLY) {
                     SV* invlist;
-                    char* formatted;
                     char* name;
 
                    if (UCHARAT(RExC_parse) == '^') {
@@ -13468,7 +13577,7 @@ parseit:
                           * that bit) */
                          value ^= 'P' ^ 'p';
 
-                        while (isSPACE(UCHARAT(RExC_parse))) {
+                        while (isSPACE(*RExC_parse)) {
                              RExC_parse++;
                              n--;
                         }
@@ -13478,14 +13587,13 @@ parseit:
                      * will have its name be <__NAME_i>.  The design is
                      * discussed in commit
                      * 2f833f5208e26b208886e51e09e2c072b5eabb46 */
-                    formatted = Perl_form(aTHX_
+                    name = savepv(Perl_form(aTHX_
                                           "%s%.*s%s\n",
                                           (FOLD) ? "__" : "",
                                           (int)n,
                                           RExC_parse,
                                           (FOLD) ? "_i" : ""
-                                );
-                    name = savepvn(formatted, strlen(formatted));
+                                ));
 
                     /* Look up the property name, and get its swash and
                      * inversion list, if the property is found  */
@@ -13499,6 +13607,9 @@ parseit:
                                              &swash_init_flags
                                             );
                     if (! swash || ! (invlist = _get_swash_invlist(swash))) {
+                        HV* curpkg = (IN_PERL_COMPILETIME)
+                                      ? PL_curstash
+                                      : CopSTASH(PL_curcop);
                         if (swash) {
                             SvREFCNT_dec_NN(swash);
                             swash = NULL;
@@ -13514,6 +13625,22 @@ parseit:
                                 "Property '%"UTF8f"' is unknown",
                                 UTF8fARG(UTF, n, name));
                         }
+
+                        /* If the property name doesn't already have a package
+                         * name, add the current one to it so that it can be
+                         * referred to outside it. [perl #121777] */
+                        if (curpkg && ! instr(name, "::")) {
+                            char* pkgname = HvNAME(curpkg);
+                            if (strNE(pkgname, "main")) {
+                                char* full_name = Perl_form(aTHX_
+                                                            "%s::%s",
+                                                            pkgname,
+                                                            name);
+                                n = strlen(full_name);
+                                Safefree(name);
+                                name = savepvn(full_name, n);
+                            }
+                        }
                         Perl_sv_catpvf(aTHX_ listsv, "%cutf8::%"UTF8f"\n",
                                         (value == 'p' ? '+' : '!'),
                                         UTF8fARG(UTF, n, name));
@@ -13582,7 +13709,7 @@ parseit:
            case 't':   value = '\t';                   break;
            case 'f':   value = '\f';                   break;
            case 'b':   value = '\b';                   break;
-           case 'e':   value = ASCII_TO_NATIVE('\033');break;
+           case 'e':   value = ESC_NATIVE;             break;
            case 'a':   value = '\a';                   break;
            case 'o':
                RExC_parse--;   /* function expects to be pointed at the 'o' */
@@ -13753,6 +13880,11 @@ parseit:
                     ANYOF_POSIXL_ZERO(ret);
                 }
 
+                /* Coverity thinks it is possible for this to be negative; both
+                 * jhi and khw think it's not, but be safer */
+                assert(! (ANYOF_FLAGS(ret) & ANYOF_POSIXL)
+                       || (namedclass + ((namedclass % 2) ? -1 : 1)) >= 0);
+
                 /* See if it already matches the complement of this POSIX
                  * class */
                 if ((ANYOF_FLAGS(ret) & ANYOF_POSIXL)
@@ -13853,7 +13985,7 @@ parseit:
 
         if (skip_white) {
             RExC_parse = regpatws(pRExC_state, RExC_parse,
-                                FALSE /* means don't recognize comments */);
+                                FALSE /* means don't recognize comments */ );
         }
 
        if (range) {
@@ -13963,7 +14095,7 @@ parseit:
                         AV* this_array;
                         STRLEN cp_count = utf8_length(foldbuf,
                                                       foldbuf + foldlen);
-                        SV* multi_fold = sv_2mortal(newSVpvn("", 0));
+                        SV* multi_fold = sv_2mortal(newSVpvs(""));
 
                         Perl_sv_catpvf(aTHX_ multi_fold, "\\x{%"UVXf"}", value);
 
@@ -14030,7 +14162,7 @@ parseit:
                 && ((prevvalue >= 'a' && value <= 'z')
                     || (prevvalue >= 'A' && value <= 'Z')))
             {
-                _invlist_intersection(this_range, PL_ASCII,
+                _invlist_intersection(this_range, PL_XPosix_ptrs[_CC_ASCII],
                                       &this_range);
 
                 /* Since this above only contains ascii, the intersection of it
@@ -14238,6 +14370,26 @@ parseit:
                     op = POSIXA;
                 }
             }
+            else if (prevvalue == 'A') {
+                if (value == 'Z'
+#ifdef EBCDIC
+                    && literal_endpoint == 2
+#endif
+                ) {
+                    arg = (FOLD) ? _CC_ALPHA : _CC_UPPER;
+                    op = POSIXA;
+                }
+            }
+            else if (prevvalue == 'a') {
+                if (value == 'z'
+#ifdef EBCDIC
+                    && literal_endpoint == 2
+#endif
+                ) {
+                    arg = (FOLD) ? _CC_ALPHA : _CC_LOWER;
+                    op = POSIXA;
+                }
+            }
         }
 
         /* Here, we have changed <op> away from its initial value iff we found
@@ -14333,18 +14485,7 @@ parseit:
                 /* This is a hash that for a particular fold gives all
                  * characters that are involved in it */
                 if (! PL_utf8_foldclosures) {
-
-                    /* If the folds haven't been read in, call a fold function
-                     * to force that */
-                    if (! PL_utf8_tofold) {
-                        U8 dummy[UTF8_MAXBYTES_CASE+1];
-
-                        /* This string is just a short named one above \xff */
-                        to_utf8_fold((U8*) HYPHEN_UTF8, dummy, NULL);
-                        assert(PL_utf8_tofold); /* Verify that worked */
-                    }
-                    PL_utf8_foldclosures
-                                      = _swash_inversion_hash(PL_utf8_tofold);
+                    _load_PL_utf8_foldclosures();
                 }
             }
 
@@ -14361,15 +14502,6 @@ parseit:
 
                     if (j < 256) {
 
-                        /* We have the latin1 folding rules hard-coded here so
-                         * that an innocent-looking character class, like
-                         * /[ks]/i won't have to go out to disk to find the
-                         * possible matches.  XXX It would be better to
-                         * generate these via regen, in case a new version of
-                         * the Unicode standard adds new mappings, though that
-                         * is not really likely, and may be caught by the
-                         * default: case of the switch below. */
-
                         if (IS_IN_SOME_FOLD_L1(j)) {
 
                             /* ASCII is always matched; non-ASCII is matched
@@ -14386,72 +14518,12 @@ parseit:
                             }
                         }
 
-                        if (HAS_NONLATIN1_FOLD_CLOSURE(j)
+                        if (HAS_NONLATIN1_SIMPLE_FOLD_CLOSURE(j)
                             && (! isASCII(j) || ! ASCII_FOLD_RESTRICTED))
                         {
-                            /* Certain Latin1 characters have matches outside
-                            * Latin1.  To get here, <j> is one of those
-                            * characters.   None of these matches is valid for
-                            * ASCII characters under /aa, which is why the 'if'
-                            * just above excludes those.  These matches only
-                            * happen when the target string is utf8.  The code
-                            * below adds the single fold closures for <j> to the
-                            * inversion list. */
-
-                            switch (j) {
-                                case 'k':
-                                case 'K':
-                                  *use_list =
-                                     add_cp_to_invlist(*use_list, KELVIN_SIGN);
-                                    break;
-                                case 's':
-                                case 'S':
-                                  *use_list = add_cp_to_invlist(*use_list,
-                                                    LATIN_SMALL_LETTER_LONG_S);
-                                    break;
-                                case MICRO_SIGN:
-                                  *use_list = add_cp_to_invlist(*use_list,
-                                                      GREEK_CAPITAL_LETTER_MU);
-                                  *use_list = add_cp_to_invlist(*use_list,
-                                                        GREEK_SMALL_LETTER_MU);
-                                    break;
-                                case LATIN_CAPITAL_LETTER_A_WITH_RING_ABOVE:
-                                case LATIN_SMALL_LETTER_A_WITH_RING_ABOVE:
-                                  *use_list =
-                                   add_cp_to_invlist(*use_list, ANGSTROM_SIGN);
-                                    break;
-                                case LATIN_SMALL_LETTER_Y_WITH_DIAERESIS:
-                                  *use_list = add_cp_to_invlist(*use_list,
-                                        LATIN_CAPITAL_LETTER_Y_WITH_DIAERESIS);
-                                    break;
-                                case LATIN_SMALL_LETTER_SHARP_S:
-                                  *use_list = add_cp_to_invlist(*use_list,
-                                                 LATIN_CAPITAL_LETTER_SHARP_S);
-                                    break;
-                                case 'F': case 'f':
-                                case 'I': case 'i':
-                                case 'L': case 'l':
-                                case 'T': case 't':
-                                case 'A': case 'a':
-                                case 'H': case 'h':
-                                case 'J': case 'j':
-                                case 'N': case 'n':
-                                case 'W': case 'w':
-                                case 'Y': case 'y':
-                                    /* These all are targets of multi-character
-                                     * folds from code points that require UTF8
-                                     * to express, so they can't match unless
-                                     * the target string is in UTF-8, so no
-                                     * action here is necessary, as regexec.c
-                                     * properly handles the general case for
-                                     * UTF-8 matching and multi-char folds */
-                                    break;
-                                default:
-                                    /* Use deprecated warning to increase the
-                                    * chances of this being output */
-                                    ckWARN2reg_d(RExC_parse, "Perl folding rules are not up-to-date for 0x%"UVXf"; please use the perlbug utility to report;", j);
-                                    break;
-                            }
+                            add_above_Latin1_folds(pRExC_state,
+                                                   (U8) j,
+                                                   use_list);
                         }
                         continue;
                     }
@@ -14480,9 +14552,8 @@ parseit:
                         for (k = 0; k <= av_tindex(list); k++) {
                             SV** c_p = av_fetch(list, k, FALSE);
                             UV c;
-                            if (c_p == NULL) {
-                                Perl_croak(aTHX_ "panic: invalid PL_utf8_foldclosures structure");
-                            }
+                            assert(c_p);
+
                             c = SvUV(*c_p);
 
                             /* /aa doesn't allow folds between ASCII and non- */
@@ -14662,7 +14733,8 @@ parseit:
      * at compile time.  Besides not inverting folded locale now, we can't
      * invert if there are things such as \w, which aren't known until runtime
      * */
-    if (invert
+    if (cp_list
+        && invert
         && ! (ANYOF_FLAGS(ret) & (ANYOF_LOCALE_FLAGS))
        && ! depends_list
        && ! HAS_NONLOCALE_RUNTIME_PROPERTY_DEFINITION)
@@ -14717,7 +14789,7 @@ parseit:
            /* We don't optimize if we are supposed to make sure all non-Unicode
             * code points raise a warning, as only ANYOF nodes have this check.
             * */
-        && ! ((ANYOF_FLAGS(ret) | ANYOF_WARN_SUPER) && ALWAYS_WARN_SUPER))
+        && ! ((ANYOF_FLAGS(ret) & ANYOF_WARN_SUPER) && ALWAYS_WARN_SUPER))
     {
         UV start, end;
         U8 op = END;  /* The optimzation node-type */
@@ -14920,6 +14992,7 @@ S_set_ANYOF_arg(pTHX_ RExC_state_t* const pRExC_state,
        av_store(av, 0, (runtime_defns)
                        ? SvREFCNT_inc(runtime_defns) : &PL_sv_undef);
        if (swash) {
+           assert(cp_list);
            av_store(av, 1, swash);
            SvREFCNT_dec_NN(cp_list);
        }
@@ -14945,38 +15018,153 @@ S_set_ANYOF_arg(pTHX_ RExC_state_t* const pRExC_state,
     }
 }
 
+#if !defined(PERL_IN_XSUB_RE) || defined(PLUGGABLE_RE_EXTENSION)
+
+SV *
+Perl__get_regclass_nonbitmap_data(pTHX_ const regexp *prog,
+                                        const regnode* node,
+                                        bool doinit,
+                                        SV** listsvp,
+                                        SV** only_utf8_locale_ptr)
+{
+    /* For internal core use only.
+     * Returns the swash for the input 'node' in the regex 'prog'.
+     * If <doinit> is 'true', will attempt to create the swash if not already
+     *   done.
+     * If <listsvp> is non-null, will return the printable contents of the
+     *    swash.  This can be used to get debugging information even before the
+     *    swash exists, by calling this function with 'doinit' set to false, in
+     *    which case the components that will be used to eventually create the
+     *    swash are returned  (in a printable form).
+     * Tied intimately to how S_set_ANYOF_arg sets up the data structure */
+
+    SV *sw  = NULL;
+    SV *si  = NULL;         /* Input swash initialization string */
+    SV*  invlist = NULL;
+
+    RXi_GET_DECL(prog,progi);
+    const struct reg_data * const data = prog ? progi->data : NULL;
+
+    PERL_ARGS_ASSERT__GET_REGCLASS_NONBITMAP_DATA;
+
+    assert(ANYOF_FLAGS(node)
+                        & (ANYOF_UTF8|ANYOF_NONBITMAP_NON_UTF8|ANYOF_LOC_FOLD));
+
+    if (data && data->count) {
+       const U32 n = ARG(node);
+
+       if (data->what[n] == 's') {
+           SV * const rv = MUTABLE_SV(data->data[n]);
+           AV * const av = MUTABLE_AV(SvRV(rv));
+           SV **const ary = AvARRAY(av);
+           U8 swash_init_flags = _CORE_SWASH_INIT_ACCEPT_INVLIST;
+
+           si = *ary;  /* ary[0] = the string to initialize the swash with */
+
+           /* Elements 3 and 4 are either both present or both absent. [3] is
+            * any inversion list generated at compile time; [4] indicates if
+            * that inversion list has any user-defined properties in it. */
+            if (av_tindex(av) >= 2) {
+                if (only_utf8_locale_ptr
+                    && ary[2]
+                    && ary[2] != &PL_sv_undef)
+                {
+                    *only_utf8_locale_ptr = ary[2];
+                }
+                else {
+                    assert(only_utf8_locale_ptr);
+                    *only_utf8_locale_ptr = NULL;
+                }
+
+                if (av_tindex(av) >= 3) {
+                    invlist = ary[3];
+                    if (SvUV(ary[4])) {
+                        swash_init_flags |= _CORE_SWASH_INIT_USER_DEFINED_PROPERTY;
+                    }
+                }
+                else {
+                    invlist = NULL;
+                }
+           }
+
+           /* Element [1] is reserved for the set-up swash.  If already there,
+            * return it; if not, create it and store it there */
+           if (ary[1] && SvROK(ary[1])) {
+               sw = ary[1];
+           }
+           else if (doinit && ((si && si != &PL_sv_undef)
+                                 || (invlist && invlist != &PL_sv_undef))) {
+               assert(si);
+               sw = _core_swash_init("utf8", /* the utf8 package */
+                                     "", /* nameless */
+                                     si,
+                                     1, /* binary */
+                                     0, /* not from tr/// */
+                                     invlist,
+                                     &swash_init_flags);
+               (void)av_store(av, 1, sw);
+           }
+       }
+    }
+
+    /* If requested, return a printable version of what this swash matches */
+    if (listsvp) {
+       SV* matches_string = newSVpvs("");
+
+        /* The swash should be used, if possible, to get the data, as it
+         * contains the resolved data.  But this function can be called at
+         * compile-time, before everything gets resolved, in which case we
+         * return the currently best available information, which is the string
+         * that will eventually be used to do that resolving, 'si' */
+       if ((! sw || (invlist = _get_swash_invlist(sw)) == NULL)
+            && (si && si != &PL_sv_undef))
+        {
+           sv_catsv(matches_string, si);
+       }
+
+       /* Add the inversion list to whatever we have.  This may have come from
+        * the swash, or from an input parameter */
+       if (invlist) {
+           sv_catsv(matches_string, _invlist_contents(invlist));
+       }
+       *listsvp = matches_string;
+    }
+
+    return sw;
+}
+
+#endif /* !defined(PERL_IN_XSUB_RE) || defined(PLUGGABLE_RE_EXTENSION) */
 
 /* reg_skipcomment()
 
-   Absorbs an /x style # comments from the input stream.
-   Returns true if there is more text remaining in the stream.
-   Will set the REG_RUN_ON_COMMENT_SEEN flag if the comment
-   terminates the pattern without including a newline.
+   Absorbs an /x style # comment from the input stream,
+   returning a pointer to the first character beyond the comment, or if the
+   comment terminates the pattern without anything following it, this returns
+   one past the final character of the pattern (in other words, RExC_end) and
+   sets the REG_RUN_ON_COMMENT_SEEN flag.
 
-   Note its the callers responsibility to ensure that we are
+   Note it's the callers responsibility to ensure that we are
    actually in /x mode
 
 */
 
-STATIC bool
-S_reg_skipcomment(pTHX_ RExC_state_t *pRExC_state)
+PERL_STATIC_INLINE char*
+S_reg_skipcomment(RExC_state_t *pRExC_state, char* p)
 {
-    bool ended = 0;
-
     PERL_ARGS_ASSERT_REG_SKIPCOMMENT;
 
-    while (RExC_parse < RExC_end)
-        if (*RExC_parse++ == '\n') {
-            ended = 1;
-            break;
+    assert(*p == '#');
+
+    while (p < RExC_end) {
+        if (*(++p) == '\n') {
+            return p+1;
         }
-    if (!ended) {
-        /* we ran off the end of the pattern without ending
-           the comment, so we have to add an \n when wrapping */
-        RExC_seen |= REG_RUN_ON_COMMENT_SEEN;
-        return 0;
-    } else
-        return 1;
+    }
+
+    /* we ran off the end of the pattern without ending the comment, so we have
+     * to add an \n when wrapping */
+    RExC_seen |= REG_RUN_ON_COMMENT_SEEN;
+    return p;
 }
 
 /* nextchar()
@@ -15014,16 +15202,14 @@ S_nextchar(pTHX_ RExC_state_t *pRExC_state)
            continue;
        }
        if (RExC_flags & RXf_PMf_EXTENDED) {
-           if (isSPACE(*RExC_parse)) {
-               RExC_parse++;
-               continue;
-           }
-           else if (*RExC_parse == '#') {
-               if ( reg_skipcomment( pRExC_state ) )
-                   continue;
-           }
+            char * p = regpatws(pRExC_state, RExC_parse,
+                                          TRUE); /* means recognize comments */
+            if (p != RExC_parse) {
+                RExC_parse = p;
+                continue;
+            }
        }
-       return retval;
+        return retval;
     }
 }
 
@@ -15033,7 +15219,6 @@ S_nextchar(pTHX_ RExC_state_t *pRExC_state)
 STATIC regnode *                       /* Location. */
 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
 {
-    dVAR;
     regnode *ptr;
     regnode * const ret = RExC_emit;
     GET_RE_DEBUG_FLAGS_DECL;
@@ -15047,7 +15232,7 @@ S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
     }
     if (RExC_emit >= RExC_emit_bound)
         Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %d, %p>=%p",
-                  op, RExC_emit, RExC_emit_bound);
+                  op, (void*)RExC_emit, (void*)RExC_emit_bound);
 
     NODE_ALIGN_FILL(ret);
     ptr = ret;
@@ -15076,7 +15261,6 @@ S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
 STATIC regnode *                       /* Location. */
 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
 {
-    dVAR;
     regnode *ptr;
     regnode * const ret = RExC_emit;
     GET_RE_DEBUG_FLAGS_DECL;
@@ -15104,7 +15288,7 @@ S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
     }
     if (RExC_emit >= RExC_emit_bound)
         Perl_croak(aTHX_ "panic: reg_node overrun trying to emit %d, %p>=%p",
-                  op, RExC_emit, RExC_emit_bound);
+                  op, (void*)RExC_emit, (void*)RExC_emit_bound);
 
     NODE_ALIGN_FILL(ret);
     ptr = ret;
@@ -15134,8 +15318,6 @@ S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
 PERL_STATIC_INLINE STRLEN
 S_reguni(pTHX_ const RExC_state_t *pRExC_state, UV uv, char* s)
 {
-    dVAR;
-
     PERL_ARGS_ASSERT_REGUNI;
 
     return SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
@@ -15149,7 +15331,6 @@ S_reguni(pTHX_ const RExC_state_t *pRExC_state, UV uv, char* s)
 STATIC void
 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
 {
-    dVAR;
     regnode *src;
     regnode *dst;
     regnode *place;
@@ -15158,6 +15339,7 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_REGINSERT;
+    PERL_UNUSED_CONTEXT;
     PERL_UNUSED_ARG(depth);
 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
     DEBUG_PARSE_FMT("inst"," - %s",PL_reg_name[op]);
@@ -15240,7 +15422,6 @@ STATIC void
 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p,
                 const regnode *val,U32 depth)
 {
-    dVAR;
     regnode *scan;
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -15300,7 +15481,6 @@ STATIC U8
 S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p,
                       const regnode *val,U32 depth)
 {
-    dVAR;
     regnode *scan;
     U8 exact = PSEUDO;
 #ifdef EXPERIMENTAL_INPLACESCAN
@@ -15463,7 +15643,6 @@ void
 Perl_regdump(pTHX_ const regexp *r)
 {
 #ifdef DEBUGGING
-    dVAR;
     SV * const sv = sv_newmortal();
     SV *dsv= sv_newmortal();
     RXi_GET_DECL(r,ri);
@@ -15562,7 +15741,6 @@ void
 Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o, const regmatch_info *reginfo)
 {
 #ifdef DEBUGGING
-    dVAR;
     int k;
 
     /* Should be synchronized with * ANYOF_ #xdefines in regcomp.h */
@@ -15665,7 +15843,7 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o, const regmatch_
         );
         if ( IS_ANYOF_TRIE(op) || trie->bitmap ) {
             sv_catpvs(sv, "[");
-            (void) put_latin1_charclass_innards(sv, IS_ANYOF_TRIE(op)
+            (void) put_charclass_bitmap_innards(sv, IS_ANYOF_TRIE(op)
                                                    ? ANYOF_BITMAP(o)
                                                    : TRIE_BITMAP(trie));
             sv_catpvs(sv, "]");
@@ -15741,8 +15919,9 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o, const regmatch_
        if (flags & ANYOF_INVERT)
            sv_catpvs(sv, "^");
 
-       /* output what the standard cp 0-255 bitmap matches */
-        do_sep = put_latin1_charclass_innards(sv, ANYOF_BITMAP(o));
+        /* output what the standard cp 0-NUM_ANYOF_CODE_POINTS-1 bitmap matches
+         * */
+        do_sep = put_charclass_bitmap_innards(sv, ANYOF_BITMAP(o));
 
         /* output any special charclass tests (used entirely under use
          * locale) * */
@@ -15891,7 +16070,6 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o, const regmatch_
 SV *
 Perl_re_intuit_string(pTHX_ REGEXP * const r)
 {                              /* Assume that RE_INTUIT is set */
-    dVAR;
     struct regexp *const prog = ReANY(r);
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -15939,7 +16117,6 @@ Perl_pregfree(pTHX_ REGEXP *r)
 void
 Perl_pregfree2(pTHX_ REGEXP *rx)
 {
-    dVAR;
     struct regexp *const r = ReANY(rx);
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -16068,7 +16245,6 @@ Perl_reg_temp_copy (pTHX_ REGEXP *ret_x, REGEXP *rx)
 void
 Perl_regfree_internal(pTHX_ REGEXP * const rx)
 {
-    dVAR;
     struct regexp *const r = ReANY(rx);
     RXi_GET_DECL(r,ri);
     GET_RE_DEBUG_FLAGS_DECL;
@@ -16121,6 +16297,9 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
                      Used in stclass optimization only */
                     U32 refcount;
                     reg_ac_data *aho=(reg_ac_data*)ri->data->data[n];
+#ifdef USE_ITHREADS
+                    dVAR;
+#endif
                     OP_REFCNT_LOCK;
                     refcount = --aho->refcount;
                     OP_REFCNT_UNLOCK;
@@ -16129,7 +16308,16 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
                         PerlMemShared_free(aho->fail);
                         /* do this last!!!! */
                         PerlMemShared_free(ri->data->data[n]);
-                        PerlMemShared_free(ri->regstclass);
+                        /* we should only ever get called once, so
+                         * assert as much, and also guard the free
+                         * which /might/ happen twice. At the least
+                         * it will make code anlyzers happy and it
+                         * doesn't cost much. - Yves */
+                        assert(ri->regstclass);
+                        if (ri->regstclass) {
+                            PerlMemShared_free(ri->regstclass);
+                            ri->regstclass = 0;
+                        }
                     }
                 }
                 break;
@@ -16138,6 +16326,9 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
                    /* trie structure. */
                    U32 refcount;
                    reg_trie_data *trie=(reg_trie_data*)ri->data->data[n];
+#ifdef USE_ITHREADS
+                    dVAR;
+#endif
                     OP_REFCNT_LOCK;
                     refcount = --trie->refcount;
                     OP_REFCNT_UNLOCK;
@@ -16343,12 +16534,12 @@ Perl_regdupe_internal(pTHX_ REGEXP * const rx, CLONE_PARAMS *param)
                 * when the corresponding reg_ac_data struct is freed.
                 */
                reti->regstclass= ri->regstclass;
-               /* Fall through */
+               /* FALLTHROUGH */
            case 't':
                OP_REFCNT_LOCK;
                ((reg_trie_data*)ri->data->data[i])->refcount++;
                OP_REFCNT_UNLOCK;
-               /* Fall through */
+               /* FALLTHROUGH */
            case 'l':
            case 'L':
                d->data[i] = ri->data->data[i];
@@ -16388,7 +16579,6 @@ Perl_regdupe_internal(pTHX_ REGEXP * const rx, CLONE_PARAMS *param)
 regnode *
 Perl_regnext(pTHX_ regnode *p)
 {
-    dVAR;
     I32 offset;
 
     if (!p)
@@ -16444,8 +16634,6 @@ S_re_croak2(pTHX_ bool utf8, const char* pat1,const char* pat2,...)
 void
 Perl_save_re_context(pTHX)
 {
-    dVAR;
-
     /* Save $1..$n (#18107: UTF-8 s/(\w+)/uc($1)/e); AMS 20021106. */
     if (PL_curpm) {
        const REGEXP * const rx = PM_GETRE(PL_curpm);
@@ -16478,11 +16666,11 @@ S_put_byte(pTHX_ SV *sv, int c)
 
     if (!isPRINT(c)) {
         switch (c) {
-            case '\r': Perl_sv_catpvf(aTHX_ sv, "\\r"); break;
+            case '\a': Perl_sv_catpvf(aTHX_ sv, "\\a"); break;
+            case '\f': Perl_sv_catpvf(aTHX_ sv, "\\f"); break;
             case '\n': Perl_sv_catpvf(aTHX_ sv, "\\n"); break;
+            case '\r': Perl_sv_catpvf(aTHX_ sv, "\\r"); break;
             case '\t': Perl_sv_catpvf(aTHX_ sv, "\\t"); break;
-            case '\f': Perl_sv_catpvf(aTHX_ sv, "\\f"); break;
-            case '\a': Perl_sv_catpvf(aTHX_ sv, "\\a"); break;
 
             default:
                 Perl_sv_catpvf(aTHX_ sv, "\\x{%x}", c);
@@ -16502,45 +16690,110 @@ S_put_range(pTHX_ SV *sv, UV start, UV end)
 {
 
     /* Appends to 'sv' a displayable version of the range of code points from
-     * 'start' to 'end' */
+     * 'start' to 'end'.  It assumes that only ASCII printables are displayable
+     * as-is (though some of these will be escaped by put_byte()). */
 
     assert(start <= end);
 
     PERL_ARGS_ASSERT_PUT_RANGE;
 
-    if (end - start < 3) {  /* Individual chars in short ranges */
-        for (; start <= end; start++)
-            put_byte(sv, start);
-    }
-    else if (   end > 255
-             || ! isALPHANUMERIC(start)
-             || ! isALPHANUMERIC(end)
-             || isDIGIT(start) != isDIGIT(end)
-             || isUPPER(start) != isUPPER(end)
-             || isLOWER(start) != isLOWER(end)
-
-                /* This final test should get optimized out except on EBCDIC
-                 * platforms, where it causes ranges that cross discontinuities
-                 * like i/j to be shown as hex instead of the misleading,
-                 * e.g. H-K (since that range includes more than H, I, J, K).
-                 * */
-             || (end - start) != NATIVE_TO_ASCII(end) - NATIVE_TO_ASCII(start))
-    {
+    while (start <= end) {
+        if (end - start < 3) {  /* Individual chars in short ranges */
+            for (; start <= end; start++) {
+                put_byte(sv, start);
+            }
+            break;
+        }
+
+        /* For small ranges that include printable ASCII characters, it's more
+         * legible to print those characters rather than hex values.  For
+         * larger ranges that include more than printables, it's probably
+         * clearer to just give the start and end points of the range in hex,
+         * and that's all we can do if there aren't any printables within the
+         * range
+         *
+         * On ASCII platforms the range of printables is contiguous.  If the
+         * entire range is printable, we print each character as such.  If the
+         * range is partially printable and partially not, it's less likely
+         * that the individual printables are meaningful, especially if all or
+         * almost all of them are in the range.  But we err on the side of the
+         * individual printables being meaningful by using the hex only if the
+         * range contains all but 2 of the printables.
+         *
+         * On EBCDIC platforms, the printables are scattered around so that the
+         * maximum range length containing only them is about 10.  Anything
+         * longer we treat as hex; otherwise we examine the range character by
+         * character to see */
+#ifdef EBCDIC
+        if (start < 256 && (((end < 255) ? end : 255) - start <= 10))
+#else
+        if ((isPRINT_A(start) && isPRINT_A(end))
+            || (end >= 0x7F && (isPRINT_A(start) && start > 0x21))
+            || ((end < 0x7D && isPRINT_A(end)) && start < 0x20))
+#endif
+        {
+            /* If the range beginning isn't an ASCII printable, we find the
+             * last such in the range, then split the output, so all the
+             * non-printables are in one subrange; then process the remaining
+             * portion as usual.  If the entire range isn't printables, we
+             * don't split, but drop down to print as hex */
+            if (! isPRINT_A(start)) {
+                UV temp_end = start + 1;
+                while (temp_end <= end && ! isPRINT_A(temp_end)) {
+                    temp_end++;
+                }
+                if (temp_end <= end) {
+                    put_range(sv, start, temp_end - 1);
+                    start = temp_end;
+                    continue;
+                }
+            }
+
+            /* If the range beginning is a digit, output a subrange of just the
+             * digits, then process the remaining portion as usual */
+            if (isDIGIT_A(start)) {
+                put_byte(sv, start);
+                sv_catpvs(sv, "-");
+                while (start <= end && isDIGIT_A(start)) start++;
+                put_byte(sv, start - 1);
+                continue;
+            }
+
+            /* Similarly for alphabetics.  Because in both ASCII and EBCDIC,
+             * the code points for upper and lower A-Z and a-z aren't
+             * intermixed, the resulting subrange will consist solely of either
+             * upper- or lower- alphabetics */
+            if (isALPHA_A(start)) {
+                put_byte(sv, start);
+                sv_catpvs(sv, "-");
+                while (start <= end && isALPHA_A(start)) start++;
+                put_byte(sv, start - 1);
+                continue;
+            }
+
+            /* We output any remaining printables as individual characters */
+            if (isPUNCT_A(start) || isSPACE_A(start)) {
+                while (start <= end && (isPUNCT_A(start) || isSPACE_A(start))) {
+                    put_byte(sv, start);
+                    start++;
+                }
+                continue;
+            }
+        }
+
+        /* Here is a control or non-ascii.  Output the range or subrange as
+         * hex. */
         Perl_sv_catpvf(aTHX_ sv, "\\x{%02" UVXf "}-\\x{%02" UVXf "}",
                        start,
-                       (end < 256) ? end : 255);
-    }
-    else { /* Here, the ends of the range are both digits, or both uppercase,
-              or both lowercase; and there's no discontinuity in the range
-              (which could happen on EBCDIC platforms) */
-        put_byte(sv, start);
-        sv_catpvs(sv, "-");
-        put_byte(sv, end);
+                       (end < NUM_ANYOF_CODE_POINTS)
+                       ? end
+                       : NUM_ANYOF_CODE_POINTS - 1);
+        break;
     }
 }
 
 STATIC bool
-S_put_latin1_charclass_innards(pTHX_ SV *sv, char *bitmap)
+S_put_charclass_bitmap_innards(pTHX_ SV *sv, char *bitmap)
 {
     /* Appends to 'sv' a displayable version of the innards of the bracketed
      * character class whose bitmap is 'bitmap';  Returns 'TRUE' if it actually
@@ -16549,15 +16802,15 @@ S_put_latin1_charclass_innards(pTHX_ SV *sv, char *bitmap)
     int i;
     bool has_output_anything = FALSE;
 
-    PERL_ARGS_ASSERT_PUT_LATIN1_CHARCLASS_INNARDS;
+    PERL_ARGS_ASSERT_PUT_CHARCLASS_BITMAP_INNARDS;
 
-    for (i = 0; i < 256; i++) {
-        if (i < 256 && BITMAP_TEST((U8 *) bitmap,i)) {
+    for (i = 0; i < NUM_ANYOF_CODE_POINTS; i++) {
+        if (BITMAP_TEST((U8 *) bitmap,i)) {
 
             /* The character at index i should be output.  Find the next
              * character that should NOT be output */
             int j;
-            for (j = i + 1; j <= 256; j++) {
+            for (j = i + 1; j < NUM_ANYOF_CODE_POINTS; j++) {
                 if (! BITMAP_TEST((U8 *) bitmap, j)) {
                     break;
                 }
@@ -16590,7 +16843,6 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
            const regnode *last, const regnode *plast,
            SV* sv, I32 indent, U32 depth)
 {
-    dVAR;
     U8 op = PSEUDO;    /* Arbitrary non-END op. */
     const regnode *next;
     const regnode *optstart= NULL;
@@ -16609,6 +16861,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
         last= plast;
 
     while (PL_regkind[op] != END && (!last || node < last)) {
+        assert(node);
        /* While that wasn't END last time... */
        NODE_ALIGN(node);
        op = OP(node);