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regcomp.c: Convert some things to use cBOOL()
[perl5.git] / regcomp.c
index 10f97b9..ff9f87b 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -85,6 +85,8 @@
 #  include "regcomp.h"
 #endif
 
+#include "dquote_static.c"
+
 #ifdef op
 #undef op
 #endif /* op */
@@ -132,7 +134,6 @@ typedef struct RExC_state_t {
     I32                orig_utf8;      /* whether the pattern was originally in utf8 */
                                /* XXX use this for future optimisation of case
                                 * where pattern must be upgraded to utf8. */
-    HV         *charnames;             /* cache of named sequences */
     HV         *paren_names;           /* Paren names */
     
     regnode    **recurse;              /* Recurse regops */
@@ -177,7 +178,6 @@ typedef struct RExC_state_t {
 #define RExC_seen_evals        (pRExC_state->seen_evals)
 #define RExC_utf8      (pRExC_state->utf8)
 #define RExC_orig_utf8 (pRExC_state->orig_utf8)
-#define RExC_charnames  (pRExC_state->charnames)
 #define RExC_open_parens       (pRExC_state->open_parens)
 #define RExC_close_parens      (pRExC_state->close_parens)
 #define RExC_opend     (pRExC_state->opend)
@@ -198,7 +198,10 @@ typedef struct RExC_state_t {
  */
 #define        WORST           0       /* Worst case. */
 #define        HASWIDTH        0x01    /* Known to match non-null strings. */
-#define        SIMPLE          0x02    /* Simple enough to be STAR/PLUS operand. */
+
+/* Simple enough to be STAR/PLUS operand, in an EXACT node must be a single
+ * character, and if utf8, must be invariant. */
+#define        SIMPLE          0x02
 #define        SPSTART         0x04    /* Starts with * or +. */
 #define TRYAGAIN       0x08    /* Weeded out a declaration. */
 #define POSTPONED      0x10    /* (?1),(?&name), (??{...}) or similar */
@@ -220,6 +223,11 @@ typedef struct RExC_state_t {
 #define PAREN_SET(u8str,paren) PBYTE(u8str,paren) |= PBITVAL(paren)
 #define PAREN_UNSET(u8str,paren) PBYTE(u8str,paren) &= (~PBITVAL(paren))
 
+/* If not already in utf8, do a longjmp back to the beginning */
+#define UTF8_LONGJMP 42 /* Choose a value not likely to ever conflict */
+#define REQUIRE_UTF8   STMT_START {                                       \
+                                     if (! UTF) JMPENV_JUMP(UTF8_LONGJMP); \
+                        } STMT_END
 
 /* About scan_data_t.
 
@@ -360,9 +368,10 @@ static const scan_data_t zero_scan_data =
 #define SCF_TRIE_RESTUDY        0x4000 /* Do restudy? */
 #define SCF_SEEN_ACCEPT         0x8000 
 
-#define UTF (RExC_utf8 != 0)
-#define LOC ((RExC_flags & RXf_PMf_LOCALE) != 0)
-#define FOLD ((RExC_flags & RXf_PMf_FOLD) != 0)
+#define UTF cBOOL(RExC_utf8)
+#define LOC cBOOL(RExC_flags & RXf_PMf_LOCALE)
+#define UNI_SEMANTICS cBOOL(RExC_flags & RXf_PMf_UNICODE)
+#define FOLD cBOOL(RExC_flags & RXf_PMf_FOLD)
 
 #define OOB_UNICODE            12345678
 #define OOB_NAMEDCLASS         -1
@@ -880,6 +889,7 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
     U32 state;
     SV *sv=sv_newmortal();
     int colwidth= widecharmap ? 6 : 4;
+    U16 word;
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_DUMP_TRIE;
@@ -949,6 +959,13 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
         }
         PerlIO_printf( Perl_debug_log, "\n" );
     }
+    PerlIO_printf(Perl_debug_log, "%*sword_info N:(prev,len)=", (int)depth*2, "");
+    for (word=1; word <= trie->wordcount; word++) {
+       PerlIO_printf(Perl_debug_log, " %d:(%d,%d)",
+           (int)word, (int)(trie->wordinfo[word].prev),
+           (int)(trie->wordinfo[word].len));
+    }
+    PerlIO_printf(Perl_debug_log, "\n" );
 }    
 /*
   Dumps a fully constructed but uncompressed trie in list form.
@@ -1079,6 +1096,7 @@ S_dump_trie_interim_table(pTHX_ const struct _reg_trie_data *trie,
 
 #endif
 
+
 /* make_trie(startbranch,first,last,tail,word_count,flags,depth)
   startbranch: the first branch in the whole branch sequence
   first      : start branch of sequence of branch-exact nodes.
@@ -1259,8 +1277,6 @@ is the recommended Unicode-aware way of saying
     U16 dupe= trie->states[ state ].wordnum;                    \
     regnode * const noper_next = regnext( noper );              \
                                                                 \
-    if (trie->wordlen)                                          \
-        trie->wordlen[ curword ] = wordlen;                     \
     DEBUG_r({                                                   \
         /* store the word for dumping */                        \
         SV* tmp;                                                \
@@ -1272,6 +1288,9 @@ is the recommended Unicode-aware way of saying
     });                                                         \
                                                                 \
     curword++;                                                  \
+    trie->wordinfo[curword].prev   = 0;                         \
+    trie->wordinfo[curword].len    = wordlen;                   \
+    trie->wordinfo[curword].accept = state;                     \
                                                                 \
     if ( noper_next < tail ) {                                  \
         if (!trie->jump)                                        \
@@ -1284,16 +1303,11 @@ is the recommended Unicode-aware way of saying
     }                                                           \
                                                                 \
     if ( dupe ) {                                               \
-        /* So it's a dupe. This means we need to maintain a   */\
-        /* linked-list from the first to the next.            */\
-        /* we only allocate the nextword buffer when there    */\
-        /* a dupe, so first time we have to do the allocation */\
-        if (!trie->nextword)                                    \
-            trie->nextword = (U16 *)                                   \
-               PerlMemShared_calloc( word_count + 1, sizeof(U16));     \
-        while ( trie->nextword[dupe] )                          \
-            dupe= trie->nextword[dupe];                         \
-        trie->nextword[dupe]= curword;                          \
+        /* It's a dupe. Pre-insert into the wordinfo[].prev   */\
+        /* chain, so that when the bits of chain are later    */\
+        /* linked together, the dups appear in the chain      */\
+       trie->wordinfo[curword].prev = trie->wordinfo[dupe].prev; \
+       trie->wordinfo[dupe].prev = curword;                    \
     } else {                                                    \
         /* we haven't inserted this word yet.                */ \
         trie->states[ state ].wordnum = curword;                \
@@ -1331,6 +1345,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     regnode *jumper = NULL;
     regnode *nextbranch = NULL;
     regnode *convert = NULL;
+    U32 *prev_states; /* temp array mapping each state to previous one */
     /* we just use folder as a flag in utf8 */
     const U8 * const folder = ( flags == EXACTF
                        ? PL_fold
@@ -1366,6 +1381,9 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     trie->charmap = (U16 *) PerlMemShared_calloc( 256, sizeof(U16) );
     if (!(UTF && folder))
        trie->bitmap = (char *) PerlMemShared_calloc( ANYOF_BITMAP_SIZE, 1 );
+    trie->wordinfo = (reg_trie_wordinfo *) PerlMemShared_calloc(
+                       trie->wordcount+1, sizeof(reg_trie_wordinfo));
+
     DEBUG_r({
         trie_words = newAV();
     });
@@ -1498,7 +1516,6 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                (int)TRIE_CHARCOUNT(trie), trie->uniquecharcount,
                (int)trie->minlen, (int)trie->maxlen )
     );
-    trie->wordlen = (U32 *) PerlMemShared_calloc( word_count, sizeof(U32) );
 
     /*
         We now know what we are dealing with in terms of unique chars and
@@ -1522,6 +1539,9 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
     */
 
 
+    Newx(prev_states, TRIE_CHARCOUNT(trie) + 2, U32);
+    prev_states[1] = 0;
+
     if ( (IV)( ( TRIE_CHARCOUNT(trie) + 1 ) * trie->uniquecharcount + 1) > SvIV(re_trie_maxbuff) ) {
         /*
             Second Pass -- Array Of Lists Representation
@@ -1592,6 +1612,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                         }
                         if ( ! newstate ) {
                             newstate = next_alloc++;
+                           prev_states[newstate] = state;
                             TRIE_LIST_PUSH( state, charid, newstate );
                             transcount++;
                         }
@@ -1775,6 +1796,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                         if ( !trie->trans[ state + charid ].next ) {
                             trie->trans[ state + charid ].next = next_alloc;
                             trie->trans[ state ].check++;
+                           prev_states[TRIE_NODENUM(next_alloc)]
+                                   = TRIE_NODENUM(state);
                             next_alloc += trie->uniquecharcount;
                         }
                         state = trie->trans[ state + charid ].next;
@@ -1922,9 +1945,6 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
        PerlMemShared_realloc( trie->trans, trie->lasttrans
                               * sizeof(reg_trie_trans) );
 
-    /* and now dump out the compressed format */
-    DEBUG_TRIE_COMPILE_r(dump_trie(trie, widecharmap, revcharmap, depth+1));
-
     {   /* Modify the program and insert the new TRIE node*/ 
         U8 nodetype =(U8)(flags & 0xFF);
         char *str=NULL;
@@ -2054,6 +2074,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
                    break;
                }
            }
+           trie->prefixlen = (state-1);
             if (str) {
                 regnode *n = convert+NODE_SZ_STR(convert);
                 NEXT_OFF(convert) = NODE_SZ_STR(convert);
@@ -2149,6 +2170,42 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch, regnode *firs
             Set_Node_Offset_Length(convert,mjd_offset,mjd_nodelen);
         });
     } /* end node insert */
+
+    /*  Finish populating the prev field of the wordinfo array.  Walk back
+     *  from each accept state until we find another accept state, and if
+     *  so, point the first word's .prev field at the second word. If the
+     *  second already has a .prev field set, stop now. This will be the
+     *  case either if we've already processed that word's accept state,
+     *  or that that state had multiple words, and the overspill words
+     *  were already linked up earlier.
+     */
+    {
+       U16 word;
+       U32 state;
+       U16 prev;
+
+       for (word=1; word <= trie->wordcount; word++) {
+           prev = 0;
+           if (trie->wordinfo[word].prev)
+               continue;
+           state = trie->wordinfo[word].accept;
+           while (state) {
+               state = prev_states[state];
+               if (!state)
+                   break;
+               prev = trie->states[state].wordnum;
+               if (prev)
+                   break;
+           }
+           trie->wordinfo[word].prev = prev;
+       }
+       Safefree(prev_states);
+    }
+
+
+    /* and now dump out the compressed format */
+    DEBUG_TRIE_COMPILE_r(dump_trie(trie, widecharmap, revcharmap, depth+1));
+
     RExC_rxi->data->data[ data_slot + 1 ] = (void*)widecharmap;
 #ifdef DEBUGGING
     RExC_rxi->data->data[ data_slot + TRIE_WORDS_OFFSET ] = (void*)trie_words;
@@ -3070,7 +3127,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
            }
            flags &= ~SCF_DO_STCLASS;
        }
-       else if (strchr((const char*)PL_varies,OP(scan))) {
+       else if (REGNODE_VARIES(OP(scan))) {
            I32 mincount, maxcount, minnext, deltanext, fl = 0;
            I32 f = flags, pos_before = 0;
            regnode * const oscan = scan;
@@ -3222,7 +3279,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
                    /* Skip open. */
                    nxt = regnext(nxt);
-                   if (!strchr((const char*)PL_simple,OP(nxt))
+                   if (!REGNODE_SIMPLE(OP(nxt))
                        && !(PL_regkind[OP(nxt)] == EXACT
                             && STR_LEN(nxt) == 1))
                        goto nogo;
@@ -3243,11 +3300,11 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
 #ifdef DEBUGGING
                    OP(nxt1 + 1) = OPTIMIZED; /* was count. */
-                   NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
-                   NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
+                   NEXT_OFF(nxt1+ 1) = 0; /* just for consistency. */
+                   NEXT_OFF(nxt2) = 0; /* just for consistency with CURLY. */
                    OP(nxt) = OPTIMIZED;        /* was CLOSE. */
                    OP(nxt + 1) = OPTIMIZED; /* was count. */
-                   NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
+                   NEXT_OFF(nxt+ 1) = 0; /* just for consistency. */
 #endif
                }
              nogo:
@@ -3270,12 +3327,10 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                        nxt = nxt2;
                    OP(nxt2)  = SUCCEED; /* Whas WHILEM */
                    /* Need to optimize away parenths. */
-                   if (data->flags & SF_IN_PAR) {
+                   if ((data->flags & SF_IN_PAR) && OP(nxt) == CLOSE) {
                        /* Set the parenth number.  */
                        regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
 
-                       if (OP(nxt) != CLOSE)
-                           FAIL("Panic opt close");
                        oscan->flags = (U8)ARG(nxt);
                        if (RExC_open_parens) {
                            RExC_open_parens[ARG(nxt1)-1]=oscan; /*open->CURLYM*/
@@ -3481,7 +3536,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                data->longest = &(data->longest_float);
            }
        }
-       else if (strchr((const char*)PL_simple,OP(scan))) {
+       else if (REGNODE_SIMPLE(OP(scan))) {
            int value = 0;
 
            if (flags & SCF_DO_SUBSTR) {
@@ -4225,6 +4280,8 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 pm_flags)
     I32 minlen = 0;
     I32 sawplus = 0;
     I32 sawopen = 0;
+    U8 jump_ret = 0;
+    dJMPENV;
     scan_data_t data;
     RExC_state_t RExC_state;
     RExC_state_t * const pRExC_state = &RExC_state;
@@ -4248,7 +4305,39 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 pm_flags)
                       PL_colors[4],PL_colors[5],s);
     });
 
-redo_first_pass:
+    /* Longjmp back to here if have to switch in midstream to utf8 */
+    if (! RExC_orig_utf8) {
+       JMPENV_PUSH(jump_ret);
+    }
+
+    if (jump_ret != 0) {
+        STRLEN len = plen;
+
+        /* Here, we longjmped back.  If the cause was other than changing to
+         * utf8, pop our own setjmp, and longjmp to the correct handler */
+       if (jump_ret != UTF8_LONGJMP) {
+           JMPENV_POP;
+           JMPENV_JUMP(jump_ret);
+       }
+
+       GET_RE_DEBUG_FLAGS;
+
+        /* It's possible to write a regexp in ascii that represents Unicode
+        codepoints outside of the byte range, such as via \x{100}. If we
+        detect such a sequence we have to convert the entire pattern to utf8
+        and then recompile, as our sizing calculation will have been based
+        on 1 byte == 1 character, but we will need to use utf8 to encode
+        at least some part of the pattern, and therefore must convert the whole
+        thing.
+        -- dmq */
+        DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
+           "UTF8 mismatch! Converting to utf8 for resizing and compile\n"));
+        exp = (char*)Perl_bytes_to_utf8(aTHX_ (U8*)SvPV(pattern, plen), &len);
+        xend = exp + len;
+        RExC_orig_utf8 = RExC_utf8 = 1;
+        SAVEFREEPV(exp);
+    }
+
     RExC_precomp = exp;
     RExC_flags = pm_flags;
     RExC_sawback = 0;
@@ -4268,7 +4357,6 @@ redo_first_pass:
     RExC_size = 0L;
     RExC_emit = &PL_regdummy;
     RExC_whilem_seen = 0;
-    RExC_charnames = NULL;
     RExC_open_parens = NULL;
     RExC_close_parens = NULL;
     RExC_opend = NULL;
@@ -4288,24 +4376,14 @@ redo_first_pass:
        RExC_precomp = NULL;
        return(NULL);
     }
-    if (RExC_utf8 && !RExC_orig_utf8) {
-        /* It's possible to write a regexp in ascii that represents Unicode
-        codepoints outside of the byte range, such as via \x{100}. If we
-        detect such a sequence we have to convert the entire pattern to utf8
-        and then recompile, as our sizing calculation will have been based
-        on 1 byte == 1 character, but we will need to use utf8 to encode
-        at least some part of the pattern, and therefore must convert the whole
-        thing.
-        XXX: somehow figure out how to make this less expensive...
-        -- dmq */
-        STRLEN len = plen;
-        DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
-           "UTF8 mismatch! Converting to utf8 for resizing and compile\n"));
-        exp = (char*)Perl_bytes_to_utf8(aTHX_ (U8*)exp, &len);
-        xend = exp + len;
-        RExC_orig_utf8 = RExC_utf8;
-        SAVEFREEPV(exp);
-        goto redo_first_pass;
+
+    /* Here, finished first pass.  Get rid of our setjmp, which we added for
+     * efficiency only if the passed-in string wasn't in utf8, as shown by
+     * RExC_orig_utf8.  But if the first pass was redone, that variable will be
+     * 1 here even though the original string wasn't utf8, but in this case
+     * there will have been a long jump */
+    if (jump_ret == UTF8_LONGJMP || ! RExC_orig_utf8) {
+       JMPENV_POP;
     }
     DEBUG_PARSE_r({
         PerlIO_printf(Perl_debug_log, 
@@ -4353,33 +4431,37 @@ redo_first_pass:
                            >> RXf_PMf_STD_PMMOD_SHIFT);
        const char *fptr = STD_PAT_MODS;        /*"msix"*/
        char *p;
-       const STRLEN wraplen = plen + has_minus + has_p + has_runon
+        /* Allocate for the worst case, which is all the std flags are turned
+         * on, but this means no caret.  We never output a minus, as all those
+         * are defaults, so are covered by the caret */
+       const STRLEN wraplen = plen + has_p + has_runon
             + (sizeof(STD_PAT_MODS) - 1)
             + (sizeof("(?:)") - 1);
 
        p = sv_grow(MUTABLE_SV(rx), wraplen + 1);
-       SvCUR_set(rx, wraplen);
        SvPOK_on(rx);
        SvFLAGS(rx) |= SvUTF8(pattern);
         *p++='('; *p++='?';
+
+        /* If a default, cover it using the caret */
+        if (has_minus || (r->extflags & ~(RXf_PMf_LOCALE|RXf_PMf_UNICODE))) {
+            *p++= DEFAULT_PAT_MOD;
+        }
+        if (r->extflags & RXf_PMf_LOCALE) {
+            *p++ = LOCALE_PAT_MOD;
+        }
+        else if (r->extflags & RXf_PMf_UNICODE) {
+            *p++ = UNICODE_PAT_MOD;
+        }
         if (has_p)
             *p++ = KEEPCOPY_PAT_MOD; /*'p'*/
         {
-            char *r = p + (sizeof(STD_PAT_MODS) - 1) + has_minus - 1;
-            char *colon = r + 1;
             char ch;
-
             while((ch = *fptr++)) {
                 if(reganch & 1)
                     *p++ = ch;
-                else
-                    *r-- = ch;
                 reganch >>= 1;
             }
-            if(has_minus) {
-                *r = '-';
-                p = colon;
-            }
         }
 
         *p++ = ':';
@@ -4391,6 +4473,7 @@ redo_first_pass:
             *p++ = '\n';
         *p++ = ')';
         *p = 0;
+       SvCUR_set(rx, p - SvPVX_const(rx));
     }
 
     r->intflags = 0;
@@ -4559,7 +4642,7 @@ reStudy:
            ri->regstclass = trie_op;
        }
 #endif 
-       else if (strchr((const char*)PL_simple,OP(first)))
+       else if (REGNODE_SIMPLE(OP(first)))
            ri->regstclass = first;
        else if (PL_regkind[OP(first)] == BOUND ||
                 PL_regkind[OP(first)] == NBOUND)
@@ -4900,7 +4983,7 @@ reStudy:
 #endif
 #ifdef DEBUGGING
     if (RExC_paren_names) {
-        ri->name_list_idx = add_data( pRExC_state, 1, "p" );
+        ri->name_list_idx = add_data( pRExC_state, 1, "a" );
         ri->data->data[ri->name_list_idx] = (void*)SvREFCNT_inc(RExC_paren_name_list);
     } else
 #endif
@@ -4950,7 +5033,7 @@ Perl_reg_named_buff(pTHX_ REGEXP * const rx, SV * const key, SV * const value,
     if (flags & RXapif_FETCH) {
         return reg_named_buff_fetch(rx, key, flags);
     } else if (flags & (RXapif_STORE | RXapif_DELETE | RXapif_CLEAR)) {
-        Perl_croak(aTHX_ "%s", PL_no_modify);
+        Perl_croak_no_modify(aTHX);
         return NULL;
     } else if (flags & RXapif_EXISTS) {
         return reg_named_buff_exists(rx, key, flags)
@@ -5250,7 +5333,7 @@ Perl_reg_numbered_buff_store(pTHX_ REGEXP * const rx, const I32 paren,
     PERL_UNUSED_ARG(value);
 
     if (!PL_localizing)
-        Perl_croak(aTHX_ "%s", PL_no_modify);
+        Perl_croak_no_modify(aTHX);
 }
 
 I32
@@ -5591,6 +5674,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
        if (*RExC_parse == '?') { /* (?...) */
            bool is_logical = 0;
            const char * const seqstart = RExC_parse;
+            bool has_use_defaults = FALSE;
 
            RExC_parse++;
            paren = *RExC_parse++;
@@ -5720,7 +5804,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                RExC_parse++;
            case '=':           /* (?=...) */
                RExC_seen_zerolen++;
-                       break;
+                break;
            case '!':           /* (?!...) */
                RExC_seen_zerolen++;
                if (*RExC_parse == ')') {
@@ -6045,12 +6129,19 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                RExC_parse--; /* for vFAIL to print correctly */
                 vFAIL("Sequence (? incomplete");
                 break;
+            case DEFAULT_PAT_MOD:   /* Use default flags with the exceptions
+                                      that follow */
+                has_use_defaults = TRUE;
+                STD_PMMOD_FLAGS_CLEAR(&RExC_flags);
+                RExC_flags &= ~(RXf_PMf_LOCALE|RXf_PMf_UNICODE);
+                goto parse_flags;
            default:
                --RExC_parse;
                parse_flags:      /* (?i) */  
            {
                 U32 posflags = 0, negflags = 0;
                U32 *flagsp = &posflags;
+                bool has_charset_modifier = 0;
 
                while (*RExC_parse) {
                    /* && strchr("iogcmsx", *RExC_parse) */
@@ -6058,6 +6149,32 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                       and must be globally applied -- japhy */
                     switch (*RExC_parse) {
                    CASE_STD_PMMOD_FLAGS_PARSE_SET(flagsp);
+                    case LOCALE_PAT_MOD:
+                        if (has_charset_modifier || flagsp == &negflags) {
+                            goto fail_modifiers;
+                        }
+                        *flagsp &= ~RXf_PMf_UNICODE;
+                        *flagsp |= RXf_PMf_LOCALE;
+                        has_charset_modifier = 1;
+                        break;
+                    case UNICODE_PAT_MOD:
+                        if (has_charset_modifier || flagsp == &negflags) {
+                            goto fail_modifiers;
+                        }
+                        *flagsp &= ~RXf_PMf_LOCALE;
+                        *flagsp |= RXf_PMf_UNICODE;
+                        has_charset_modifier = 1;
+                        break;
+                    case DUAL_PAT_MOD:
+                        if (has_use_defaults
+                            || has_charset_modifier
+                            || flagsp == &negflags)
+                        {
+                            goto fail_modifiers;
+                        }
+                        *flagsp &= ~(RXf_PMf_LOCALE|RXf_PMf_UNICODE);
+                        has_charset_modifier = 1;
+                        break;
                     case ONCE_PAT_MOD: /* 'o' */
                     case GLOBAL_PAT_MOD: /* 'g' */
                        if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
@@ -6098,7 +6215,11 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                         }
                        break;
                     case '-':
-                        if (flagsp == &negflags) {
+                        /* A flag is a default iff it is following a minus,  so
+                         * if there is a minus, it means will be trying to
+                         * re-specify a default which is an error */
+                        if (has_use_defaults || flagsp == &negflags) {
+            fail_modifiers:
                             RExC_parse++;
                            vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
                            /*NOTREACHED*/
@@ -6589,56 +6710,72 @@ S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
    recognized '\N' and needs to handle the rest. RExC_parse is
    expected to point at the first char following the N at the time
    of the call.
+
+   The \N may be inside (indicated by valuep not being NULL) or outside a
+   character class.
+
+   \N may begin either a named sequence, or if outside a character class, mean
+   to match a non-newline.  For non single-quoted regexes, the tokenizer has
+   attempted to decide which, and in the case of a named sequence converted it
+   into one of the forms: \N{} (if the sequence is null), or \N{U+c1.c2...},
+   where c1... are the characters in the sequence.  For single-quoted regexes,
+   the tokenizer passes the \N sequence through unchanged; this code will not
+   attempt to determine this nor expand those.  The net effect is that if the
+   beginning of the passed-in pattern isn't '{U+' or there is no '}', it
+   signals that this \N occurrence means to match a non-newline.
+   
+   Only the \N{U+...} form should occur in a character class, for the same
+   reason that '.' inside a character class means to just match a period: it
+   just doesn't make sense.
    
    If valuep is non-null then it is assumed that we are parsing inside 
    of a charclass definition and the first codepoint in the resolved
    string is returned via *valuep and the routine will return NULL. 
    In this mode if a multichar string is returned from the charnames 
-   handler a warning will be issued, and only the first char in the 
+   handler, a warning will be issued, and only the first char in the 
    sequence will be examined. If the string returned is zero length
    then the value of *valuep is undefined and NON-NULL will 
    be returned to indicate failure. (This will NOT be a valid pointer 
    to a regnode.)
    
-   If valuep is null then it is assumed that we are parsing normal text
-   and inserts a new EXACT node into the program containing the resolved
-   string and returns a pointer to the new node. If the string is 
-   zerolength a NOTHING node is emitted.
+   If valuep is null then it is assumed that we are parsing normal text and a
+   new EXACT node is inserted into the program containing the resolved string,
+   and a pointer to the new node is returned.  But if the string is zero length
+   a NOTHING node is emitted instead.
 
    On success RExC_parse is set to the char following the endbrace.
-   Parsing failures will generate a fatal errorvia vFAIL(...)
-   
-   NOTE: We cache all results from the charnames handler locally in 
-   the RExC_charnames hash (created on first use) to prevent a charnames 
-   handler from playing silly-buggers and returning a short string and 
-   then a long string for a given pattern. Since the regexp program 
-   size is calculated during an initial parse this would result
-   in a buffer overrun so we cache to prevent the charname result from
-   changing during the course of the parse.
-   
+   Parsing failures will generate a fatal error via vFAIL(...)
  */
 STATIC regnode *
 S_reg_namedseq(pTHX_ RExC_state_t *pRExC_state, UV *valuep, I32 *flagp)
 {
-    char * name;        /* start of the content of the name */
-    char * endbrace;    /* endbrace following the name */
-    SV *sv_str = NULL;  
-    SV *sv_name = NULL;
-    STRLEN len; /* this has various purposes throughout the code */
-    bool cached = 0; /* if this is true then we shouldn't refcount dev sv_str */
+    char * endbrace;    /* '}' following the name */
     regnode *ret = NULL;
+#ifdef DEBUGGING
+    char* parse_start = RExC_parse - 2;            /* points to the '\N' */
+#endif
+    char* p;
+
+    GET_RE_DEBUG_FLAGS_DECL;
  
     PERL_ARGS_ASSERT_REG_NAMEDSEQ;
+
+    GET_RE_DEBUG_FLAGS;
+
+    /* The [^\n] meaning of \N ignores spaces and comments under the /x
+     * modifier.  The other meaning does not */
+    p = (RExC_flags & RXf_PMf_EXTENDED)
+       ? regwhite( pRExC_state, RExC_parse )
+       : RExC_parse;
    
-    if (*RExC_parse != '{' ||
-           (*RExC_parse == '{' && RExC_parse[1]
-            && strchr("0123456789", RExC_parse[1])))
-    {
-       GET_RE_DEBUG_FLAGS_DECL;
-       if (valuep)
+    /* 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)) {
+       RExC_parse = p;
+       if (valuep) {
            /* no bare \N in a charclass */
-           vFAIL("Missing braces on \\N{}");
-       GET_RE_DEBUG_FLAGS;
+           vFAIL("\\N in a character class must be a named character: \\N{...}");
+       }
        nextchar(pRExC_state);
        ret = reg_node(pRExC_state, REG_ANY);
        *flagp |= HASWIDTH|SIMPLE;
@@ -6647,232 +6784,199 @@ S_reg_namedseq(pTHX_ RExC_state_t *pRExC_state, UV *valuep, I32 *flagp)
         Set_Node_Length(ret, 1); /* MJD */
        return ret;
     }
-    name = RExC_parse+1;
-    endbrace = strchr(RExC_parse, '}');
-    if ( ! endbrace ) {
-        RExC_parse++;
-        vFAIL("Missing right brace on \\N{}");
-    } 
-    RExC_parse = endbrace + 1;  
-    
-    
-    /* RExC_parse points at the beginning brace, 
-       endbrace points at the last */
-    if ( name[0]=='U' && name[1]=='+' ) {
-        /* its a "Unicode hex" notation {U+89AB} */
-        I32 fl = PERL_SCAN_ALLOW_UNDERSCORES
-            | PERL_SCAN_DISALLOW_PREFIX
-            | (SIZE_ONLY ? PERL_SCAN_SILENT_ILLDIGIT : 0);
-        UV cp;
-        len = (STRLEN)(endbrace - name - 2);
-        cp = grok_hex(name + 2, &len, &fl, NULL);
-        if ( len != (STRLEN)(endbrace - name - 2) ) {
-            cp = 0xFFFD;
-        }    
-        if ( valuep ) {
-           if (cp > 0xff) RExC_utf8 = 1;
-            *valuep = cp;
-            return NULL;
-        }
 
-       /* Need to convert to utf8 if either: won't fit into a byte, or the re
-        * is going to be in utf8 and the representation changes under utf8. */
-       if (cp > 0xff || (RExC_utf8 && ! UNI_IS_INVARIANT(cp))) {
-           U8 string[UTF8_MAXBYTES+1];
-           U8 *tmps;
-           RExC_utf8 = 1;
-           tmps = uvuni_to_utf8(string, cp);
-           sv_str = newSVpvn_utf8((char*)string, tmps - string, TRUE);
-       } else {    /* Otherwise, no need for utf8, can skip that step */
-           char string;
-           string = (char)cp;
-           sv_str= newSVpvn(&string, 1);
+    /* Here, we have decided it should be a named sequence */
+
+    /* The test above made sure that the next real character is a '{', but
+     * under the /x modifier, it could be separated by space (or a comment and
+     * \n) and this is not allowed (for consistency with \x{...} and the
+     * tokenizer handling of \N{NAME}). */
+    if (*RExC_parse != '{') {
+       vFAIL("Missing braces on \\N{}");
+    }
+
+    RExC_parse++;      /* Skip past the '{' */
+
+    if (! (endbrace = strchr(RExC_parse, '}')) /* no trailing brace */
+       || ! (endbrace == RExC_parse            /* nothing between the {} */
+             || (endbrace - RExC_parse >= 2    /* U+ (bad hex is checked below */
+                 && strnEQ(RExC_parse, "U+", 2)))) /* for a better error msg) */
+    {
+       if (endbrace) RExC_parse = endbrace;    /* position msg's '<--HERE' */
+       vFAIL("\\N{NAME} must be resolved by the lexer");
+    }
+
+    if (endbrace == RExC_parse) {   /* empty: \N{} */
+       if (! valuep) {
+           RExC_parse = endbrace + 1;  
+           return reg_node(pRExC_state,NOTHING);
        }
-    } else {
-        /* fetch the charnames handler for this scope */
-        HV * const table = GvHV(PL_hintgv);
-        SV **cvp= table ? 
-            hv_fetchs(table, "charnames", FALSE) :
-            NULL;
-        SV *cv= cvp ? *cvp : NULL;
-        HE *he_str;
-        int count;
-        /* create an SV with the name as argument */
-        sv_name = newSVpvn(name, endbrace - name);
-        
-        if (!table || !(PL_hints & HINT_LOCALIZE_HH)) {
-            vFAIL2("Constant(\\N{%" SVf "}) unknown: "
-                  "(possibly a missing \"use charnames ...\")",
-                  SVfARG(sv_name));
-        }
-        if (!cvp || !SvOK(*cvp)) { /* when $^H{charnames} = undef; */
-            vFAIL2("Constant(\\N{%" SVf "}): "
-                  "$^H{charnames} is not defined", SVfARG(sv_name));
-        }
-        
-        
-        
-        if (!RExC_charnames) {
-            /* make sure our cache is allocated */
-            RExC_charnames = newHV();
-            sv_2mortal(MUTABLE_SV(RExC_charnames));
-        } 
-            /* see if we have looked this one up before */
-        he_str = hv_fetch_ent( RExC_charnames, sv_name, 0, 0 );
-        if ( he_str ) {
-            sv_str = HeVAL(he_str);
-            cached = 1;
-        } else {
-            dSP ;
 
-            ENTER ;
-            SAVETMPS ;
-            PUSHMARK(SP) ;
-            
-            XPUSHs(sv_name);
-            
-            PUTBACK ;
-            
-            count= call_sv(cv, G_SCALAR);
-            SPAGAIN ;
-            
-            if (count == 1) { /* XXXX is this right? dmq */
-                sv_str = POPs;
-                SvREFCNT_inc_simple_void(sv_str);
-            } 
-            
-            PUTBACK ;
-            FREETMPS ;
-            LEAVE ;
-            
-            if ( !sv_str || !SvOK(sv_str) ) {
-                vFAIL2("Constant(\\N{%" SVf "}): Call to &{$^H{charnames}} "
-                      "did not return a defined value", SVfARG(sv_name));
-            }
-            if (hv_store_ent( RExC_charnames, sv_name, sv_str, 0))
-                cached = 1;
-        }
+       if (SIZE_ONLY) {
+           ckWARNreg(RExC_parse,
+                   "Ignoring zero length \\N{} in character class"
+           );
+           RExC_parse = endbrace + 1;  
+       }
+       *valuep = 0;
+       return (regnode *) &RExC_parse; /* Invalid regnode pointer */
     }
-    if (valuep) {
-        char *p = SvPV(sv_str, len);
-        if (len) {
-            STRLEN numlen = 1;
-            if ( SvUTF8(sv_str) ) {
-                *valuep = utf8_to_uvchr((U8*)p, &numlen);
-                if (*valuep > 0x7F)
-                    RExC_utf8 = 1; 
-                /* XXXX
-                  We have to turn on utf8 for high bit chars otherwise
-                  we get failures with
-                  
-                   "ss" =~ /[\N{LATIN SMALL LETTER SHARP S}]/i
-                   "SS" =~ /[\N{LATIN SMALL LETTER SHARP S}]/i
-                
-                  This is different from what \x{} would do with the same
-                  codepoint, where the condition is > 0xFF.
-                  - dmq
-                */
-                
-                
-            } else {
-                *valuep = (UV)*p;
-                /* warn if we havent used the whole string? */
-            }
-            if (numlen<len && SIZE_ONLY) {
-                ckWARN2reg(RExC_parse,
-                          "Ignoring excess chars from \\N{%" SVf "} in character class",
-                          SVfARG(sv_name)
-                );
-            }        
-        } else if (SIZE_ONLY) {
-            ckWARN2reg(RExC_parse,
-                      "Ignoring zero length \\N{%" SVf "} in character class",
-                      SVfARG(sv_name)
-                );
-        }
-        SvREFCNT_dec(sv_name);
-        if (!cached)
-            SvREFCNT_dec(sv_str);    
-        return len ? NULL : (regnode *)&len;
-    } else if(SvCUR(sv_str)) {     
-        
-        char *s; 
-        char *p, *pend;        
-        STRLEN charlen = 1;
-#ifdef DEBUGGING
-        char * parse_start = name-3; /* needed for the offsets */
-#endif
-        GET_RE_DEBUG_FLAGS_DECL;     /* needed for the offsets */
-        
-        ret = reg_node(pRExC_state,
-            (U8)(FOLD ? (LOC ? EXACTFL : EXACTF) : EXACT));
-        s= STRING(ret);
-        
-        if ( RExC_utf8 && !SvUTF8(sv_str) ) {
-            sv_utf8_upgrade(sv_str);
-        } else if ( !RExC_utf8 && SvUTF8(sv_str) ) {
-            RExC_utf8= 1;
-        }
-        
-        p = SvPV(sv_str, len);
-        pend = p + len;
-        /* len is the length written, charlen is the size the char read */
-        for ( len = 0; p < pend; p += charlen ) {
-            if (UTF) {
-                UV uvc = utf8_to_uvchr((U8*)p, &charlen);
-                if (FOLD) {
-                    STRLEN foldlen,numlen;
-                    U8 tmpbuf[UTF8_MAXBYTES_CASE+1], *foldbuf;
-                    uvc = toFOLD_uni(uvc, tmpbuf, &foldlen);
-                    /* Emit all the Unicode characters. */
-                    
-                    for (foldbuf = tmpbuf;
-                        foldlen;
-                        foldlen -= numlen) 
-                    {
-                        uvc = utf8_to_uvchr(foldbuf, &numlen);
-                        if (numlen > 0) {
-                            const STRLEN unilen = reguni(pRExC_state, uvc, s);
-                            s       += unilen;
-                            len     += unilen;
-                            /* In EBCDIC the numlen
-                            * and unilen can differ. */
-                            foldbuf += numlen;
-                            if (numlen >= foldlen)
-                                break;
-                        }
-                        else
-                            break; /* "Can't happen." */
-                    }                          
-                } else {
-                    const STRLEN unilen = reguni(pRExC_state, uvc, s);
-                   if (unilen > 0) {
-                      s   += unilen;
-                      len += unilen;
-                   }
-               }
-           } else {
-                len++;
-                REGC(*p, s++);
-            }
-        }
-        if (SIZE_ONLY) {
-            RExC_size += STR_SZ(len);
-        } else {
-            STR_LEN(ret) = len;
-            RExC_emit += STR_SZ(len);
-        }
-        Set_Node_Cur_Length(ret); /* MJD */
-        RExC_parse--; 
-        nextchar(pRExC_state);
-    } else {   /* zero length */
-        ret = reg_node(pRExC_state,NOTHING);
+
+    REQUIRE_UTF8;      /* named sequences imply Unicode semantics */
+    RExC_parse += 2;   /* Skip past the 'U+' */
+
+    if (valuep) {   /* In a bracketed char class */
+       /* We only pay attention to the first char of 
+       multichar strings being returned. I kinda wonder
+       if this makes sense as it does change the behaviour
+       from earlier versions, OTOH that behaviour was broken
+       as well. XXX Solution is to recharacterize as
+       [rest-of-class]|multi1|multi2... */
+
+       STRLEN length_of_hex;
+       I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
+           | PERL_SCAN_DISALLOW_PREFIX
+           | (SIZE_ONLY ? PERL_SCAN_SILENT_ILLDIGIT : 0);
+    
+       char * endchar = RExC_parse + strcspn(RExC_parse, ".}");
+       if (endchar < endbrace) {
+           ckWARNreg(endchar, "Using just the first character returned by \\N{} in character class");
+       }
+
+       length_of_hex = (STRLEN)(endchar - RExC_parse);
+       *valuep = grok_hex(RExC_parse, &length_of_hex, &flags, NULL);
+
+       /* The tokenizer should have guaranteed validity, but it's possible to
+        * bypass it by using single quoting, so check */
+       if (length_of_hex == 0
+           || length_of_hex != (STRLEN)(endchar - RExC_parse) )
+       {
+           RExC_parse += length_of_hex;        /* Includes all the valid */
+           RExC_parse += (RExC_orig_utf8)      /* point to after 1st invalid */
+                           ? UTF8SKIP(RExC_parse)
+                           : 1;
+           /* Guard against malformed utf8 */
+           if (RExC_parse >= endchar) RExC_parse = endchar;
+           vFAIL("Invalid hexadecimal number in \\N{U+...}");
+       }    
+
+       RExC_parse = endbrace + 1;
+       if (endchar == endbrace) return NULL;
+
+        ret = (regnode *) &RExC_parse; /* Invalid regnode pointer */
     }
-    SvREFCNT_dec(sv_name);
-    if (!cached)
-        SvREFCNT_dec(sv_str);
-    return ret;
+    else {     /* Not a char class */
+       char *s;            /* String to put in generated EXACT node */
+       STRLEN len = 0;     /* Its current byte length */
+       char *endchar;      /* Points to '.' or '}' ending cur char in the input
+                              stream */
+
+       ret = reg_node(pRExC_state,
+                       (U8)(FOLD ? (LOC ? EXACTFL : EXACTF) : EXACT));
+       s= STRING(ret);
+
+       /* Exact nodes can hold only a U8 length's of text = 255.  Loop through
+        * the input which is of the form now 'c1.c2.c3...}' until find the
+        * ending brace or exceed length 255.  The characters that exceed this
+        * limit are dropped.  The limit could be relaxed should it become
+        * desirable by reparsing this as (?:\N{NAME}), so could generate
+        * multiple EXACT nodes, as is done for just regular input.  But this
+        * is primarily a named character, and not intended to be a huge long
+        * string, so 255 bytes should be good enough */
+       while (1) {
+           STRLEN length_of_hex;
+           I32 grok_flags = PERL_SCAN_ALLOW_UNDERSCORES
+                           | PERL_SCAN_DISALLOW_PREFIX
+                           | (SIZE_ONLY ? PERL_SCAN_SILENT_ILLDIGIT : 0);
+           UV cp;  /* Ord of current character */
+
+           /* Code points are separated by dots.  If none, there is only one
+            * code point, and is terminated by the brace */
+           endchar = RExC_parse + strcspn(RExC_parse, ".}");
+
+           /* The values are Unicode even on EBCDIC machines */
+           length_of_hex = (STRLEN)(endchar - RExC_parse);
+           cp = grok_hex(RExC_parse, &length_of_hex, &grok_flags, NULL);
+           if ( length_of_hex == 0 
+               || length_of_hex != (STRLEN)(endchar - RExC_parse) )
+           {
+               RExC_parse += length_of_hex;        /* Includes all the valid */
+               RExC_parse += (RExC_orig_utf8)  /* point to after 1st invalid */
+                               ? UTF8SKIP(RExC_parse)
+                               : 1;
+               /* Guard against malformed utf8 */
+               if (RExC_parse >= endchar) RExC_parse = endchar;
+               vFAIL("Invalid hexadecimal number in \\N{U+...}");
+           }    
+
+           if (! FOLD) {       /* Not folding, just append to the string */
+               STRLEN unilen;
+
+               /* Quit before adding this character if would exceed limit */
+               if (len + UNISKIP(cp) > U8_MAX) break;
+
+               unilen = reguni(pRExC_state, cp, s);
+               if (unilen > 0) {
+                   s   += unilen;
+                   len += unilen;
+               }
+           } else {    /* Folding, output the folded equivalent */
+               STRLEN foldlen,numlen;
+               U8 tmpbuf[UTF8_MAXBYTES_CASE+1], *foldbuf;
+               cp = toFOLD_uni(cp, tmpbuf, &foldlen);
 
+               /* Quit before exceeding size limit */
+               if (len + foldlen > U8_MAX) break;
+               
+               for (foldbuf = tmpbuf;
+                   foldlen;
+                   foldlen -= numlen) 
+               {
+                   cp = utf8_to_uvchr(foldbuf, &numlen);
+                   if (numlen > 0) {
+                       const STRLEN unilen = reguni(pRExC_state, cp, s);
+                       s       += unilen;
+                       len     += unilen;
+                       /* In EBCDIC the numlen and unilen can differ. */
+                       foldbuf += numlen;
+                       if (numlen >= foldlen)
+                           break;
+                   }
+                   else
+                       break; /* "Can't happen." */
+               }                          
+           }
+
+           /* Point to the beginning of the next character in the sequence. */
+           RExC_parse = endchar + 1;
+
+           /* Quit if no more characters */
+           if (RExC_parse >= endbrace) break;
+       }
+
+
+       if (SIZE_ONLY) {
+           if (RExC_parse < endbrace) {
+               ckWARNreg(RExC_parse - 1,
+                         "Using just the first characters returned by \\N{}");
+           }
+
+           RExC_size += STR_SZ(len);
+       } else {
+           STR_LEN(ret) = len;
+           RExC_emit += STR_SZ(len);
+       }
+
+       RExC_parse = endbrace + 1;
+
+       *flagp |= HASWIDTH; /* Not SIMPLE, as that causes the engine to fail
+                              with malformed in t/re/pat_advanced.t */
+       RExC_parse --;
+       Set_Node_Cur_Length(ret); /* MJD */
+       nextchar(pRExC_state);
+    }
+
+    return ret;
 }
 
 
@@ -7434,6 +7538,35 @@ tryagain:
                          ender = ASCII_TO_NATIVE('\007');
                        p++;
                        break;
+                   case 'o':
+                       {
+                           STRLEN brace_len = len;
+                           UV result;
+                           const char* error_msg;
+
+                           bool valid = grok_bslash_o(p,
+                                                      &result,
+                                                      &brace_len,
+                                                      &error_msg,
+                                                      1);
+                           p += brace_len;
+                           if (! valid) {
+                               RExC_parse = p; /* going to die anyway; point
+                                                  to exact spot of failure */
+                               vFAIL(error_msg);
+                           }
+                           else
+                           {
+                               ender = result;
+                           }
+                           if (PL_encoding && ender < 0x100) {
+                               goto recode_encoding;
+                           }
+                           if (ender > 0xff) {
+                               REQUIRE_UTF8;
+                           }
+                           break;
+                       }
                    case 'x':
                        if (*++p == '{') {
                            char* const e = strchr(p, '}');
@@ -7448,7 +7581,7 @@ tryagain:
                                 STRLEN numlen = e - p - 1;
                                ender = grok_hex(p + 1, &numlen, &flags, NULL);
                                if (ender > 0xff)
-                                   RExC_utf8 = 1;
+                                   REQUIRE_UTF8;
                                p = e + 1;
                            }
                        }
@@ -7463,27 +7596,18 @@ tryagain:
                        break;
                    case 'c':
                        p++;
-                       ender = UCHARAT(p++);
-                       ender = toCTRL(ender);
+                       ender = grok_bslash_c(*p++, SIZE_ONLY);
                        break;
                    case '0': case '1': case '2': case '3':case '4':
                    case '5': case '6': case '7': case '8':case '9':
                        if (*p == '0' ||
-                         (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
-                            I32 flags = 0;
+                           (isOCTAL(p[1]) && atoi(p) >= RExC_npar))
+                       {
+                           I32 flags = PERL_SCAN_SILENT_ILLDIGIT;
                            STRLEN numlen = 3;
                            ender = grok_oct(p, &numlen, &flags, NULL);
-
-                           /* An octal above 0xff is interpreted differently
-                            * depending on if the re is in utf8 or not.  If it
-                            * is in utf8, the value will be itself, otherwise
-                            * it is interpreted as modulo 0x100.  It has been
-                            * decided to discourage the use of octal above the
-                            * single-byte range.  For now, warn only when
-                            * it ends up modulo */
-                           if (SIZE_ONLY && ender >= 0x100
-                                   && ! UTF && ! PL_encoding) {
-                               ckWARNregdep(p, "Use of octal value above 377 is deprecated");
+                           if (ender > 0xff) {
+                               REQUIRE_UTF8;
                            }
                            p += numlen;
                        }
@@ -7500,7 +7624,7 @@ tryagain:
                            ender = reg_recode((const char)(U8)ender, &enc);
                            if (!enc && SIZE_ONLY)
                                ckWARNreg(p, "Invalid escape in the specified encoding");
-                           RExC_utf8 = 1;
+                           REQUIRE_UTF8;
                        }
                        break;
                    case '\0':
@@ -8059,6 +8183,24 @@ parseit:
            case 'b':   value = '\b';                   break;
            case 'e':   value = ASCII_TO_NATIVE('\033');break;
            case 'a':   value = ASCII_TO_NATIVE('\007');break;
+           case 'o':
+               RExC_parse--;   /* function expects to be pointed at the 'o' */
+               {
+                   const char* error_msg;
+                   bool valid = grok_bslash_o(RExC_parse,
+                                              &value,
+                                              &numlen,
+                                              &error_msg,
+                                              SIZE_ONLY);
+                   RExC_parse += numlen;
+                   if (! valid) {
+                       vFAIL(error_msg);
+                   }
+               }
+               if (PL_encoding && value < 0x100) {
+                   goto recode_encoding;
+               }
+               break;
            case 'x':
                if (*RExC_parse == '{') {
                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
@@ -8081,13 +8223,13 @@ parseit:
                    goto recode_encoding;
                break;
            case 'c':
-               value = UCHARAT(RExC_parse++);
-               value = toCTRL(value);
+               value = grok_bslash_c(*RExC_parse++, SIZE_ONLY);
                break;
            case '0': case '1': case '2': case '3': case '4':
-           case '5': case '6': case '7': case '8': case '9':
+           case '5': case '6': case '7':
                {
-                   I32 flags = 0;
+                   /* Take 1-3 octal digits */
+                   I32 flags = PERL_SCAN_SILENT_ILLDIGIT;
                    numlen = 3;
                    value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
                    RExC_parse += numlen;
@@ -8105,10 +8247,12 @@ parseit:
                    break;
                }
            default:
-               if (!SIZE_ONLY && isALPHA(value))
+               /* Allow \_ to not give an error */
+               if (!SIZE_ONLY && isALNUM(value) && value != '_') {
                    ckWARN2reg(RExC_parse,
                               "Unrecognized escape \\%c in character class passed through",
                               (int)value);
+               }
                break;
            }
        } /* end of \blah */
@@ -8903,30 +9047,6 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p, const regnode *val,
 #endif
 
 /*
- - regcurly - a little FSA that accepts {\d+,?\d*}
- */
-STATIC I32
-S_regcurly(register const char *s)
-{
-    PERL_ARGS_ASSERT_REGCURLY;
-
-    if (*s++ != '{')
-       return FALSE;
-    if (!isDIGIT(*s))
-       return FALSE;
-    while (isDIGIT(*s))
-       s++;
-    if (*s == ',')
-       s++;
-    while (isDIGIT(*s))
-       s++;
-    if (*s != '}')
-       return FALSE;
-    return TRUE;
-}
-
-
-/*
  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
  */
 #ifdef DEBUGGING
@@ -9457,6 +9577,8 @@ Perl_reg_temp_copy (pTHX_ REGEXP *ret_x, REGEXP *rx)
     memcpy(&(ret->xpv_cur), &(r->xpv_cur),
           sizeof(regexp) - STRUCT_OFFSET(regexp, xpv_cur));
     SvLEN_set(ret_x, 0);
+    SvSTASH_set(ret_x, NULL);
+    SvMAGIC_set(ret_x, NULL);
     Newx(ret->offs, npar, regexp_paren_pair);
     Copy(r->offs, ret->offs, npar, regexp_paren_pair);
     if (r->substrs) {
@@ -9527,6 +9649,7 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
        while (--n >= 0) {
           /* If you add a ->what type here, update the comment in regcomp.h */
            switch (ri->data->what[n]) {
+           case 'a':
            case 's':
            case 'S':
            case 'u':
@@ -9588,12 +9711,9 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
                         PerlMemShared_free(trie->trans);
                         if (trie->bitmap)
                             PerlMemShared_free(trie->bitmap);
-                        if (trie->wordlen)
-                            PerlMemShared_free(trie->wordlen);
                         if (trie->jump)
                             PerlMemShared_free(trie->jump);
-                        if (trie->nextword)
-                            PerlMemShared_free(trie->nextword);
+                       PerlMemShared_free(trie->wordinfo);
                         /* do this last!!!! */
                         PerlMemShared_free(ri->data->data[n]);
                    }
@@ -9610,9 +9730,8 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
     Safefree(ri);
 }
 
-#define sv_dup_inc(s,t)        SvREFCNT_inc(sv_dup(s,t))
-#define av_dup_inc(s,t)        MUTABLE_AV(SvREFCNT_inc(sv_dup((const SV *)s,t)))
-#define hv_dup_inc(s,t)        MUTABLE_HV(SvREFCNT_inc(sv_dup((const SV *)s,t)))
+#define av_dup_inc(s,t)        MUTABLE_AV(sv_dup_inc((const SV *)s,t))
+#define hv_dup_inc(s,t)        MUTABLE_HV(sv_dup_inc((const SV *)s,t))
 #define SAVEPVN(p,n)   ((p) ? savepvn(p,n) : NULL)
 
 /* 
@@ -9764,8 +9883,9 @@ Perl_regdupe_internal(pTHX_ REGEXP * const rx, CLONE_PARAMS *param)
        for (i = 0; i < count; i++) {
            d->what[i] = ri->data->what[i];
            switch (d->what[i]) {
-               /* legal options are one of: sSfpontTu
+               /* legal options are one of: sSfpontTua
                   see also regcomp.h and pregfree() */
+           case 'a': /* actually an AV, but the dup function is identical.  */
            case 's':
            case 'S':
            case 'p': /* actually an AV, but the dup function is identical.  */
@@ -9841,6 +9961,10 @@ Perl_regnext(pTHX_ register regnode *p)
     if (!p)
        return(NULL);
 
+    if (OP(p) > REGNODE_MAX) {         /* regnode.type is unsigned */
+       Perl_croak(aTHX_ "Corrupted regexp opcode %d > %d", (int)OP(p), (int)REGNODE_MAX);
+    }
+
     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
     if (offset == 0)
        return(NULL);
@@ -9900,7 +10024,7 @@ Perl_save_re_context(pTHX)
 
     state = (struct re_save_state *)(PL_savestack + PL_savestack_ix);
     PL_savestack_ix += SAVESTACK_ALLOC_FOR_RE_SAVE_STATE;
-    SSPUSHINT(SAVEt_RE_STATE);
+    SSPUSHUV(SAVEt_RE_STATE);
 
     Copy(&PL_reg_state, state, 1, struct re_save_state);