This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Fix misleading indentation in op.c
[perl5.git] / regcomp.c
index facfb81..e6b352b 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -222,6 +222,7 @@ struct RExC_state_t {
 #endif
     bool        seen_unfolded_sharp_s;
     bool        strict;
+    bool        study_started;
 };
 
 #define RExC_flags     (pRExC_state->flags)
@@ -288,6 +289,7 @@ struct RExC_state_t {
 #define RExC_frame_last (pRExC_state->frame_last)
 #define RExC_frame_count (pRExC_state->frame_count)
 #define RExC_strict (pRExC_state->strict)
+#define RExC_study_started      (pRExC_state->study_started)
 
 /* Heuristic check on the complexity of the pattern: if TOO_NAUGHTY, we set
  * a flag to disable back-off on the fixed/floating substrings - if it's
@@ -502,7 +504,20 @@ static const scan_data_t zero_scan_data =
 #define SF_HAS_PAR             0x0080
 #define SF_IN_PAR              0x0100
 #define SF_HAS_EVAL            0x0200
+
+
+/* SCF_DO_SUBSTR is the flag that tells the regexp analyzer to track the
+ * longest substring in the pattern. When it is not set the optimiser keeps
+ * track of position, but does not keep track of the actual strings seen,
+ *
+ * So for instance /foo/ will be parsed with SCF_DO_SUBSTR being true, but
+ * /foo/i will not.
+ *
+ * Similarly, /foo.*(blah|erm|huh).*fnorble/ will have "foo" and "fnorble"
+ * parsed with SCF_DO_SUBSTR on, but while processing the (...) it will be
+ * turned off because of the alternation (BRANCH). */
 #define SCF_DO_SUBSTR          0x0400
+
 #define SCF_DO_STCLASS_AND     0x0800
 #define SCF_DO_STCLASS_OR      0x1000
 #define SCF_DO_STCLASS         (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
@@ -898,49 +913,78 @@ static const scan_data_t zero_scan_data =
 #define EXPERIMENTAL_INPLACESCAN
 #endif /*PERL_ENABLE_EXPERIMENTAL_REGEX_OPTIMISATIONS*/
 
-#define DEBUG_RExC_seen() \
+#ifdef DEBUGGING
+int
+Perl_re_printf(pTHX_ const char *fmt, ...)
+{
+    va_list ap;
+    int result;
+    PerlIO *f= Perl_debug_log;
+    PERL_ARGS_ASSERT_RE_PRINTF;
+    va_start(ap, fmt);
+    result = PerlIO_vprintf(f, fmt, ap);
+    va_end(ap);
+    return result;
+}
+
+int
+Perl_re_indentf(pTHX_ const char *fmt, U32 depth, ...)
+{
+    va_list ap;
+    int result;
+    PerlIO *f= Perl_debug_log;
+    PERL_ARGS_ASSERT_RE_INDENTF;
+    va_start(ap, depth);
+    PerlIO_printf(f, "%*s", ( (int)depth % 20 ) * 2, "");
+    result = PerlIO_vprintf(f, fmt, ap);
+    va_end(ap);
+    return result;
+}
+#endif /* DEBUGGING */
+
+#define DEBUG_RExC_seen()                                                   \
         DEBUG_OPTIMISE_MORE_r({                                             \
-            PerlIO_printf(Perl_debug_log,"RExC_seen: ");                    \
+            Perl_re_printf( aTHX_ "RExC_seen: ");                                       \
                                                                             \
             if (RExC_seen & REG_ZERO_LEN_SEEN)                              \
-                PerlIO_printf(Perl_debug_log,"REG_ZERO_LEN_SEEN ");         \
+                Perl_re_printf( aTHX_ "REG_ZERO_LEN_SEEN ");                            \
                                                                             \
             if (RExC_seen & REG_LOOKBEHIND_SEEN)                            \
-                PerlIO_printf(Perl_debug_log,"REG_LOOKBEHIND_SEEN ");       \
+                Perl_re_printf( aTHX_ "REG_LOOKBEHIND_SEEN ");                          \
                                                                             \
             if (RExC_seen & REG_GPOS_SEEN)                                  \
-                PerlIO_printf(Perl_debug_log,"REG_GPOS_SEEN ");             \
+                Perl_re_printf( aTHX_ "REG_GPOS_SEEN ");                                \
                                                                             \
             if (RExC_seen & REG_RECURSE_SEEN)                               \
-                PerlIO_printf(Perl_debug_log,"REG_RECURSE_SEEN ");          \
+                Perl_re_printf( aTHX_ "REG_RECURSE_SEEN ");                             \
                                                                             \
-            if (RExC_seen & REG_TOP_LEVEL_BRANCHES_SEEN)                         \
-                PerlIO_printf(Perl_debug_log,"REG_TOP_LEVEL_BRANCHES_SEEN ");    \
+            if (RExC_seen & REG_TOP_LEVEL_BRANCHES_SEEN)                    \
+                Perl_re_printf( aTHX_ "REG_TOP_LEVEL_BRANCHES_SEEN ");                  \
                                                                             \
             if (RExC_seen & REG_VERBARG_SEEN)                               \
-                PerlIO_printf(Perl_debug_log,"REG_VERBARG_SEEN ");          \
+                Perl_re_printf( aTHX_ "REG_VERBARG_SEEN ");                             \
                                                                             \
             if (RExC_seen & REG_CUTGROUP_SEEN)                              \
-                PerlIO_printf(Perl_debug_log,"REG_CUTGROUP_SEEN ");         \
+                Perl_re_printf( aTHX_ "REG_CUTGROUP_SEEN ");                            \
                                                                             \
             if (RExC_seen & REG_RUN_ON_COMMENT_SEEN)                        \
-                PerlIO_printf(Perl_debug_log,"REG_RUN_ON_COMMENT_SEEN ");   \
+                Perl_re_printf( aTHX_ "REG_RUN_ON_COMMENT_SEEN ");                      \
                                                                             \
             if (RExC_seen & REG_UNFOLDED_MULTI_SEEN)                        \
-                PerlIO_printf(Perl_debug_log,"REG_UNFOLDED_MULTI_SEEN ");   \
+                Perl_re_printf( aTHX_ "REG_UNFOLDED_MULTI_SEEN ");                      \
                                                                             \
-            if (RExC_seen & REG_UNBOUNDED_QUANTIFIER_SEEN)                               \
-                PerlIO_printf(Perl_debug_log,"REG_UNBOUNDED_QUANTIFIER_SEEN ");          \
+            if (RExC_seen & REG_UNBOUNDED_QUANTIFIER_SEEN)                  \
+                Perl_re_printf( aTHX_ "REG_UNBOUNDED_QUANTIFIER_SEEN ");                \
                                                                             \
-            PerlIO_printf(Perl_debug_log,"\n");                             \
+            Perl_re_printf( aTHX_ "\n");                                                \
         });
 
 #define DEBUG_SHOW_STUDY_FLAG(flags,flag) \
-  if ((flags) & flag) PerlIO_printf(Perl_debug_log, "%s ", #flag)
+  if ((flags) & flag) Perl_re_printf( aTHX_  "%s ", #flag)
 
 #define DEBUG_SHOW_STUDY_FLAGS(flags,open_str,close_str)                    \
     if ( ( flags ) ) {                                                      \
-        PerlIO_printf(Perl_debug_log, "%s", open_str);                      \
+        Perl_re_printf( aTHX_  "%s", open_str);                                         \
         DEBUG_SHOW_STUDY_FLAG(flags,SF_FL_BEFORE_SEOL);                     \
         DEBUG_SHOW_STUDY_FLAG(flags,SF_FL_BEFORE_MEOL);                     \
         DEBUG_SHOW_STUDY_FLAG(flags,SF_IS_INF);                             \
@@ -956,29 +1000,28 @@ static const scan_data_t zero_scan_data =
         DEBUG_SHOW_STUDY_FLAG(flags,SCF_SEEN_ACCEPT);                       \
         DEBUG_SHOW_STUDY_FLAG(flags,SCF_TRIE_DOING_RESTUDY);                \
         DEBUG_SHOW_STUDY_FLAG(flags,SCF_IN_DEFINE);                         \
-        PerlIO_printf(Perl_debug_log, "%s", close_str);                     \
+        Perl_re_printf( aTHX_  "%s", close_str);                                        \
     }
 
 
 #define DEBUG_STUDYDATA(str,data,depth)                              \
 DEBUG_OPTIMISE_MORE_r(if(data){                                      \
-    PerlIO_printf(Perl_debug_log,                                    \
-        "%*s" str "Pos:%"IVdf"/%"IVdf                                \
+    Perl_re_indentf( aTHX_  "" str "Pos:%"IVdf"/%"IVdf                           \
         " Flags: 0x%"UVXf,                                           \
-        (int)(depth)*2, "",                                          \
+        depth,                                                       \
         (IV)((data)->pos_min),                                       \
         (IV)((data)->pos_delta),                                     \
         (UV)((data)->flags)                                          \
     );                                                               \
     DEBUG_SHOW_STUDY_FLAGS((data)->flags," [ ","]");                 \
-    PerlIO_printf(Perl_debug_log,                                    \
+    Perl_re_printf( aTHX_                                                        \
         " Whilem_c: %"IVdf" Lcp: %"IVdf" %s",                        \
         (IV)((data)->whilem_c),                                      \
         (IV)((data)->last_closep ? *((data)->last_closep) : -1),     \
         is_inf ? "INF " : ""                                         \
     );                                                               \
     if ((data)->last_found)                                          \
-        PerlIO_printf(Perl_debug_log,                                \
+        Perl_re_printf( aTHX_                                                    \
             "Last:'%s' %"IVdf":%"IVdf"/%"IVdf" %sFixed:'%s' @ %"IVdf \
             " %sFloat: '%s' @ %"IVdf"/%"IVdf"",                      \
             SvPVX_const((data)->last_found),                         \
@@ -995,9 +1038,10 @@ DEBUG_OPTIMISE_MORE_r(if(data){                                      \
             (IV)((data)->offset_float_min),                          \
             (IV)((data)->offset_float_max)                           \
         );                                                           \
-    PerlIO_printf(Perl_debug_log,"\n");                              \
+    Perl_re_printf( aTHX_ "\n");                                                 \
 });
 
+
 /* =========================================================
  * BEGIN edit_distance stuff.
  *
@@ -1948,14 +1992,13 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
 
     PERL_ARGS_ASSERT_DUMP_TRIE;
 
-    PerlIO_printf( Perl_debug_log, "%*sChar : %-6s%-6s%-4s ",
-        (int)depth * 2 + 2,"",
-        "Match","Base","Ofs" );
+    Perl_re_indentf( aTHX_  "Char : %-6s%-6s%-4s ",
+        depth+1, "Match","Base","Ofs" );
 
     for( state = 0 ; state < trie->uniquecharcount ; state++ ) {
        SV ** const tmp = av_fetch( revcharmap, state, 0);
         if ( tmp ) {
-            PerlIO_printf( Perl_debug_log, "%*s",
+            Perl_re_printf( aTHX_  "%*s",
                 colwidth,
                 pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), colwidth,
                            PL_colors[0], PL_colors[1],
@@ -1965,27 +2008,25 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
             );
         }
     }
-    PerlIO_printf( Perl_debug_log, "\n%*sState|-----------------------",
-        (int)depth * 2 + 2,"");
+    Perl_re_printf( aTHX_  "\n");
+    Perl_re_indentf( aTHX_ "State|-----------------------", depth+1);
 
     for( state = 0 ; state < trie->uniquecharcount ; state++ )
-        PerlIO_printf( Perl_debug_log, "%.*s", colwidth, "--------");
-    PerlIO_printf( Perl_debug_log, "\n");
+        Perl_re_printf( aTHX_  "%.*s", colwidth, "--------");
+    Perl_re_printf( aTHX_  "\n");
 
     for( state = 1 ; state < trie->statecount ; state++ ) {
        const U32 base = trie->states[ state ].trans.base;
 
-        PerlIO_printf( Perl_debug_log, "%*s#%4"UVXf"|",
-                                       (int)depth * 2 + 2,"", (UV)state);
+        Perl_re_indentf( aTHX_  "#%4"UVXf"|", depth+1, (UV)state);
 
         if ( trie->states[ state ].wordnum ) {
-            PerlIO_printf( Perl_debug_log, " W%4X",
-                                           trie->states[ state ].wordnum );
+            Perl_re_printf( aTHX_  " W%4X", trie->states[ state ].wordnum );
         } else {
-            PerlIO_printf( Perl_debug_log, "%6s", "" );
+            Perl_re_printf( aTHX_  "%6s", "" );
         }
 
-        PerlIO_printf( Perl_debug_log, " @%4"UVXf" ", (UV)base );
+        Perl_re_printf( aTHX_  " @%4"UVXf" ", (UV)base );
 
         if ( base ) {
             U32 ofs = 0;
@@ -1996,7 +2037,7 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
                                                                     != state))
                     ofs++;
 
-            PerlIO_printf( Perl_debug_log, "+%2"UVXf"[ ", (UV)ofs);
+            Perl_re_printf( aTHX_  "+%2"UVXf"[ ", (UV)ofs);
 
             for ( ofs = 0 ; ofs < trie->uniquecharcount ; ofs++ ) {
                 if ( ( base + ofs >= trie->uniquecharcount )
@@ -2005,28 +2046,27 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
                         && trie->trans[ base + ofs
                                     - trie->uniquecharcount ].check == state )
                 {
-                   PerlIO_printf( Perl_debug_log, "%*"UVXf,
-                    colwidth,
-                    (UV)trie->trans[ base + ofs
-                                             - trie->uniquecharcount ].next );
+                   Perl_re_printf( aTHX_  "%*"UVXf, colwidth,
+                    (UV)trie->trans[ base + ofs - trie->uniquecharcount ].next
+                   );
                 } else {
-                    PerlIO_printf( Perl_debug_log, "%*s",colwidth,"   ." );
+                    Perl_re_printf( aTHX_  "%*s",colwidth,"   ." );
                 }
             }
 
-            PerlIO_printf( Perl_debug_log, "]");
+            Perl_re_printf( aTHX_  "]");
 
         }
-        PerlIO_printf( Perl_debug_log, "\n" );
+        Perl_re_printf( aTHX_  "\n" );
     }
-    PerlIO_printf(Perl_debug_log, "%*sword_info N:(prev,len)=",
-                                (int)depth*2, "");
+    Perl_re_indentf( aTHX_  "word_info N:(prev,len)=",
+                                depth);
     for (word=1; word <= trie->wordcount; word++) {
-       PerlIO_printf(Perl_debug_log, " %d:(%d,%d)",
+        Perl_re_printf( aTHX_  " %d:(%d,%d)",
            (int)word, (int)(trie->wordinfo[word].prev),
            (int)(trie->wordinfo[word].len));
     }
-    PerlIO_printf(Perl_debug_log, "\n" );
+    Perl_re_printf( aTHX_  "\n" );
 }
 /*
   Dumps a fully constructed but uncompressed trie in list form.
@@ -2047,19 +2087,20 @@ S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie,
     PERL_ARGS_ASSERT_DUMP_TRIE_INTERIM_LIST;
 
     /* print out the table precompression.  */
-    PerlIO_printf( Perl_debug_log, "%*sState :Word | Transition Data\n%*s%s",
-        (int)depth * 2 + 2,"", (int)depth * 2 + 2,"",
-        "------:-----+-----------------\n" );
+    Perl_re_indentf( aTHX_  "State :Word | Transition Data\n",
+            depth+1 );
+    Perl_re_indentf( aTHX_  "%s",
+            depth+1, "------:-----+-----------------\n" );
 
     for( state=1 ; state < next_alloc ; state ++ ) {
         U16 charid;
 
-        PerlIO_printf( Perl_debug_log, "%*s %4"UVXf" :",
-            (int)depth * 2 + 2,"", (UV)state  );
+        Perl_re_indentf( aTHX_  " %4"UVXf" :",
+            depth+1, (UV)state  );
         if ( ! trie->states[ state ].wordnum ) {
-            PerlIO_printf( Perl_debug_log, "%5s| ","");
+            Perl_re_printf( aTHX_  "%5s| ","");
         } else {
-            PerlIO_printf( Perl_debug_log, "W%4x| ",
+            Perl_re_printf( aTHX_  "W%4x| ",
                 trie->states[ state ].wordnum
             );
         }
@@ -2067,7 +2108,7 @@ S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie,
            SV ** const tmp = av_fetch( revcharmap,
                                         TRIE_LIST_ITEM(state,charid).forid, 0);
            if ( tmp ) {
-                PerlIO_printf( Perl_debug_log, "%*s:%3X=%4"UVXf" | ",
+                Perl_re_printf( aTHX_  "%*s:%3X=%4"UVXf" | ",
                     colwidth,
                     pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp),
                               colwidth,
@@ -2079,11 +2120,11 @@ S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie,
                     (UV)TRIE_LIST_ITEM(state,charid).newstate
                 );
                 if (!(charid % 10))
-                    PerlIO_printf(Perl_debug_log, "\n%*s| ",
+                    Perl_re_printf( aTHX_  "\n%*s| ",
                         (int)((depth * 2) + 14), "");
             }
         }
-        PerlIO_printf( Perl_debug_log, "\n");
+        Perl_re_printf( aTHX_  "\n");
     }
 }
 
@@ -2111,12 +2152,12 @@ S_dump_trie_interim_table(pTHX_ const struct _reg_trie_data *trie,
        that they are identical.
      */
 
-    PerlIO_printf( Perl_debug_log, "%*sChar : ",(int)depth * 2 + 2,"" );
+    Perl_re_indentf( aTHX_  "Char : ", depth+1 );
 
     for( charid = 0 ; charid < trie->uniquecharcount ; charid++ ) {
        SV ** const tmp = av_fetch( revcharmap, charid, 0);
         if ( tmp ) {
-            PerlIO_printf( Perl_debug_log, "%*s",
+            Perl_re_printf( aTHX_  "%*s",
                 colwidth,
                 pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), colwidth,
                            PL_colors[0], PL_colors[1],
@@ -2127,32 +2168,33 @@ S_dump_trie_interim_table(pTHX_ const struct _reg_trie_data *trie,
         }
     }
 
-    PerlIO_printf( Perl_debug_log, "\n%*sState+-",(int)depth * 2 + 2,"" );
+    Perl_re_printf( aTHX_ "\n");
+    Perl_re_indentf( aTHX_  "State+-", depth+1 );
 
     for( charid=0 ; charid < trie->uniquecharcount ; charid++ ) {
-        PerlIO_printf( Perl_debug_log, "%.*s", colwidth,"--------");
+        Perl_re_printf( aTHX_  "%.*s", colwidth,"--------");
     }
 
-    PerlIO_printf( Perl_debug_log, "\n" );
+    Perl_re_printf( aTHX_  "\n" );
 
     for( state=1 ; state < next_alloc ; state += trie->uniquecharcount ) {
 
-        PerlIO_printf( Perl_debug_log, "%*s%4"UVXf" : ",
-            (int)depth * 2 + 2,"",
+        Perl_re_indentf( aTHX_  "%4"UVXf" : ",
+            depth+1,
             (UV)TRIE_NODENUM( state ) );
 
         for( charid = 0 ; charid < trie->uniquecharcount ; charid++ ) {
             UV v=(UV)SAFE_TRIE_NODENUM( trie->trans[ state + charid ].next );
             if (v)
-                PerlIO_printf( Perl_debug_log, "%*"UVXf, colwidth, v );
+                Perl_re_printf( aTHX_  "%*"UVXf, colwidth, v );
             else
-                PerlIO_printf( Perl_debug_log, "%*s", colwidth, "." );
+                Perl_re_printf( aTHX_  "%*s", colwidth, "." );
         }
         if ( ! trie->states[ TRIE_NODENUM( state ) ].wordnum ) {
-            PerlIO_printf( Perl_debug_log, " (%4"UVXf")\n",
+            Perl_re_printf( aTHX_  " (%4"UVXf")\n",
                                             (UV)trie->trans[ state ].check );
         } else {
-            PerlIO_printf( Perl_debug_log, " (%4"UVXf") W%4X\n",
+            Perl_re_printf( aTHX_  " (%4"UVXf") W%4X\n",
                                             (UV)trie->trans[ state ].check,
             trie->states[ TRIE_NODENUM( state ) ].wordnum );
         }
@@ -2464,9 +2506,9 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
         sv_setiv(re_trie_maxbuff, RE_TRIE_MAXBUF_INIT);
     }
     DEBUG_TRIE_COMPILE_r({
-        PerlIO_printf( Perl_debug_log,
-          "%*smake_trie start==%d, first==%d, last==%d, tail==%d depth=%d\n",
-          (int)depth * 2 + 2, "",
+        Perl_re_indentf( aTHX_
+          "make_trie start==%d, first==%d, last==%d, tail==%d depth=%d\n",
+          depth+1,
           REG_NODE_NUM(startbranch),REG_NODE_NUM(first),
           REG_NODE_NUM(last), REG_NODE_NUM(tail), (int)depth);
     });
@@ -2505,8 +2547,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
 
     for ( cur = first ; cur < last ; cur = regnext( cur ) ) {
         regnode *noper = NEXTOPER( cur );
-        const U8 *uc = (U8*)STRING( noper );
-        const U8 *e  = uc + STR_LEN( noper );
+        const U8 *uc;
+        const U8 *e;
         int foldlen = 0;
         U32 wordlen      = 0;         /* required init */
         STRLEN minchars = 0;
@@ -2516,17 +2558,19 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
 
         if (OP(noper) == NOTHING) {
             regnode *noper_next= regnext(noper);
-            if (noper_next != tail && OP(noper_next) == flags) {
-                noper = noper_next;
-                uc= (U8*)STRING(noper);
-                e= uc + STR_LEN(noper);
-               trie->minlen= STR_LEN(noper);
-            } else {
-               trie->minlen= 0;
-               continue;
-           }
+            if (noper_next < tail)
+                noper= noper_next;
+        }
+
+        if ( noper < tail && ( OP(noper) == flags || ( flags == EXACTFU && OP(noper) == EXACTFU_SS ) ) ) {
+            uc= (U8*)STRING(noper);
+            e= uc + STR_LEN(noper);
+        } else {
+            trie->minlen= 0;
+            continue;
         }
 
+
         if ( set_bit ) { /* bitmap only alloced when !(UTF&&Folding) */
             TRIE_BITMAP_SET(trie,*uc); /* store the raw first byte
                                           regardless of encoding */
@@ -2669,9 +2713,9 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
         }
     } /* end first pass */
     DEBUG_TRIE_COMPILE_r(
-        PerlIO_printf( Perl_debug_log,
-                "%*sTRIE(%s): W:%d C:%d Uq:%d Min:%d Max:%d\n",
-                (int)depth * 2 + 2,"",
+        Perl_re_indentf( aTHX_
+                "TRIE(%s): W:%d C:%d Uq:%d Min:%d Max:%d\n",
+                depth+1,
                 ( widecharmap ? "UTF8" : "NATIVE" ), (int)word_count,
                (int)TRIE_CHARCOUNT(trie), trie->uniquecharcount,
                (int)trie->minlen, (int)trie->maxlen )
@@ -2719,9 +2763,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
 
         STRLEN transcount = 1;
 
-        DEBUG_TRIE_COMPILE_MORE_r( PerlIO_printf( Perl_debug_log,
-            "%*sCompiling trie using list compiler\n",
-            (int)depth * 2 + 2, ""));
+        DEBUG_TRIE_COMPILE_MORE_r( Perl_re_indentf( aTHX_  "Compiling trie using list compiler\n",
+            depth+1));
 
        trie->states = (reg_trie_state *)
            PerlMemShared_calloc( TRIE_CHARCOUNT(trie) + 2,
@@ -2732,22 +2775,20 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
         for ( cur = first ; cur < last ; cur = regnext( cur ) ) {
 
             regnode *noper   = NEXTOPER( cur );
-           U8 *uc           = (U8*)STRING( noper );
-            const U8 *e      = uc + STR_LEN( noper );
            U32 state        = 1;         /* required init */
            U16 charid       = 0;         /* sanity init */
             U32 wordlen      = 0;         /* required init */
 
             if (OP(noper) == NOTHING) {
                 regnode *noper_next= regnext(noper);
-                if (noper_next != tail && OP(noper_next) == flags) {
-                    noper = noper_next;
-                    uc= (U8*)STRING(noper);
-                    e= uc + STR_LEN(noper);
-                }
+                if (noper_next < tail)
+                    noper= noper_next;
             }
 
-            if (OP(noper) != NOTHING) {
+            if ( noper < tail && ( OP(noper) == flags || ( flags == EXACTFU && OP(noper) == EXACTFU_SS ) ) ) {
+                const U8 *uc= (U8*)STRING(noper);
+                const U8 *e= uc + STR_LEN(noper);
+
                 for ( ; uc < e ; uc += len ) {
 
                     TRIE_READ_CHAR;
@@ -2829,7 +2870,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
 
                 /*
                 DEBUG_TRIE_COMPILE_MORE_r(
-                    PerlIO_printf( Perl_debug_log, "tp: %d zp: %d ",tp,zp)
+                    Perl_re_printf( aTHX_  "tp: %d zp: %d ",tp,zp)
                 );
                 */
 
@@ -2891,7 +2932,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
                 }
                 /*
                 DEBUG_TRIE_COMPILE_MORE_r(
-                    PerlIO_printf( Perl_debug_log, " base: %d\n",base);
+                    Perl_re_printf( aTHX_  " base: %d\n",base);
                 );
                 */
                 trie->states[ state ].trans.base=base;
@@ -2934,9 +2975,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
            we have to use TRIE_NODENUM() to convert.
 
         */
-        DEBUG_TRIE_COMPILE_MORE_r( PerlIO_printf( Perl_debug_log,
-            "%*sCompiling trie using table compiler\n",
-            (int)depth * 2 + 2, ""));
+        DEBUG_TRIE_COMPILE_MORE_r( Perl_re_indentf( aTHX_  "Compiling trie using table compiler\n",
+            depth+1));
 
        trie->trans = (reg_trie_trans *)
            PerlMemShared_calloc( ( TRIE_CHARCOUNT(trie) + 1 )
@@ -2951,8 +2991,6 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
         for ( cur = first ; cur < last ; cur = regnext( cur ) ) {
 
             regnode *noper   = NEXTOPER( cur );
-           const U8 *uc     = (U8*)STRING( noper );
-            const U8 *e      = uc + STR_LEN( noper );
 
             U32 state        = 1;         /* required init */
 
@@ -2963,14 +3001,14 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
 
             if (OP(noper) == NOTHING) {
                 regnode *noper_next= regnext(noper);
-                if (noper_next != tail && OP(noper_next) == flags) {
-                    noper = noper_next;
-                    uc= (U8*)STRING(noper);
-                    e= uc + STR_LEN(noper);
-                }
+                if (noper_next < tail)
+                    noper= noper_next;
             }
 
-            if ( OP(noper) != NOTHING ) {
+            if ( noper < tail && ( OP(noper) == flags || ( flags == EXACTFU && OP(noper) == EXACTFU_SS ) ) ) {
+                const U8 *uc= (U8*)STRING(noper);
+                const U8 *e= uc + STR_LEN(noper);
+
                 for ( ; uc < e ; uc += len ) {
 
                     TRIE_READ_CHAR;
@@ -3128,9 +3166,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
            PerlMemShared_realloc( trie->states, laststate
                                   * sizeof(reg_trie_state) );
         DEBUG_TRIE_COMPILE_MORE_r(
-            PerlIO_printf( Perl_debug_log,
-                "%*sAlloc: %d Orig: %"IVdf" elements, Final:%"IVdf". Savings of %%%5.2f\n",
-                (int)depth * 2 + 2,"",
+            Perl_re_indentf( aTHX_  "Alloc: %d Orig: %"IVdf" elements, Final:%"IVdf". Savings of %%%5.2f\n",
+                depth+1,
                 (int)( ( TRIE_CHARCOUNT(trie) + 1 ) * trie->uniquecharcount
                        + 1 ),
                 (IV)next_alloc,
@@ -3141,9 +3178,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
         } /* end table compress */
     }
     DEBUG_TRIE_COMPILE_MORE_r(
-            PerlIO_printf(Perl_debug_log,
-                "%*sStatecount:%"UVxf" Lasttrans:%"UVxf"\n",
-                (int)depth * 2 + 2, "",
+            Perl_re_indentf( aTHX_  "Statecount:%"UVxf" Lasttrans:%"UVxf"\n",
+                depth+1,
                 (UV)trie->statecount,
                 (UV)trie->lasttrans)
     );
@@ -3193,9 +3229,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
             });
         }
         DEBUG_OPTIMISE_r(
-            PerlIO_printf(Perl_debug_log,
-                "%*sMJD offset:%"UVuf" MJD length:%"UVuf"\n",
-                (int)depth * 2 + 2, "",
+            Perl_re_indentf( aTHX_  "MJD offset:%"UVuf" MJD length:%"UVuf"\n",
+                depth+1,
                 (UV)mjd_offset, (UV)mjd_nodelen)
         );
 #endif
@@ -3225,9 +3260,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
                             if ( count == 2 ) {
                                 Zero(trie->bitmap, ANYOF_BITMAP_SIZE, char);
                                 DEBUG_OPTIMISE_r(
-                                    PerlIO_printf(Perl_debug_log,
-                                       "%*sNew Start State=%"UVuf" Class: [",
-                                        (int)depth * 2 + 2, "",
+                                    Perl_re_indentf( aTHX_  "New Start State=%"UVuf" Class: [",
+                                        depth+1,
                                         (UV)state));
                                if (idx >= 0) {
                                    SV ** const tmp = av_fetch( revcharmap, idx, 0);
@@ -3237,14 +3271,14 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
                                     if ( folder )
                                         TRIE_BITMAP_SET(trie, folder[ *ch ]);
                                     DEBUG_OPTIMISE_r(
-                                        PerlIO_printf(Perl_debug_log, "%s", (char*)ch)
+                                        Perl_re_printf( aTHX_  "%s", (char*)ch)
                                     );
                                }
                            }
                            TRIE_BITMAP_SET(trie,*ch);
                            if ( folder )
                                TRIE_BITMAP_SET(trie,folder[ *ch ]);
-                           DEBUG_OPTIMISE_r(PerlIO_printf( Perl_debug_log,"%s", ch));
+                            DEBUG_OPTIMISE_r(Perl_re_printf( aTHX_ "%s", ch));
                        }
                         idx = ofs;
                    }
@@ -3255,9 +3289,8 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
                     char *ch = SvPV( *tmp, len );
                     DEBUG_OPTIMISE_r({
                         SV *sv=sv_newmortal();
-                        PerlIO_printf( Perl_debug_log,
-                           "%*sPrefix State: %"UVuf" Idx:%"UVuf" Char='%s'\n",
-                            (int)depth * 2 + 2, "",
+                        Perl_re_indentf( aTHX_  "Prefix State: %"UVuf" Idx:%"UVuf" Char='%s'\n",
+                            depth+1,
                             (UV)state, (UV)idx,
                             pv_pretty(sv, SvPV_nolen_const(*tmp), SvCUR(*tmp), 6,
                                PL_colors[0], PL_colors[1],
@@ -3277,7 +3310,7 @@ S_make_trie(pTHX_ RExC_state_t *pRExC_state, regnode *startbranch,
                } else {
 #ifdef DEBUGGING
                    if (state>1)
-                       DEBUG_OPTIMISE_r(PerlIO_printf( Perl_debug_log,"]\n"));
+                        DEBUG_OPTIMISE_r(Perl_re_printf( aTHX_ "]\n"));
 #endif
                    break;
                }
@@ -3549,14 +3582,13 @@ S_construct_ahocorasick_from_trie(pTHX_ RExC_state_t *pRExC_state, regnode *sour
      */
     fail[ 0 ] = fail[ 1 ] = 0;
     DEBUG_TRIE_COMPILE_r({
-        PerlIO_printf(Perl_debug_log,
-                     "%*sStclass Failtable (%"UVuf" states): 0",
-                     (int)(depth * 2), "", (UV)numstates
+        Perl_re_indentf( aTHX_  "Stclass Failtable (%"UVuf" states): 0",
+                      depth, (UV)numstates
         );
         for( q_read=1; q_read<numstates; q_read++ ) {
-            PerlIO_printf(Perl_debug_log, ", %"UVuf, (UV)fail[q_read]);
+            Perl_re_printf( aTHX_  ", %"UVuf, (UV)fail[q_read]);
         }
-        PerlIO_printf(Perl_debug_log, "\n");
+        Perl_re_printf( aTHX_  "\n");
     });
     Safefree(q);
     /*RExC_seen |= REG_TRIEDFA_SEEN;*/
@@ -3564,15 +3596,15 @@ S_construct_ahocorasick_from_trie(pTHX_ RExC_state_t *pRExC_state, regnode *sour
 }
 
 
-#define DEBUG_PEEP(str,scan,depth) \
-    DEBUG_OPTIMISE_r({if (scan){ \
-       regnode *Next = regnext(scan); \
-       regprop(RExC_rx, RExC_mysv, scan, NULL, pRExC_state); \
-       PerlIO_printf(Perl_debug_log, "%*s" str ">%3d: %s (%d)", \
-           (int)depth*2, "", REG_NODE_NUM(scan), SvPV_nolen_const(RExC_mysv),\
-           Next ? (REG_NODE_NUM(Next)) : 0 ); \
+#define DEBUG_PEEP(str,scan,depth)         \
+    DEBUG_OPTIMISE_r({if (scan){           \
+       regnode *Next = regnext(scan);      \
+       regprop(RExC_rx, RExC_mysv, scan, NULL, pRExC_state);\
+       Perl_re_indentf( aTHX_  "" str ">%3d: %s (%d)", \
+           depth, REG_NODE_NUM(scan), SvPV_nolen_const(RExC_mysv),\
+           Next ? (REG_NODE_NUM(Next)) : 0 );\
        DEBUG_SHOW_STUDY_FLAGS(flags," [ ","]");\
-       PerlIO_printf(Perl_debug_log, "\n"); \
+       Perl_re_printf( aTHX_  "\n");                   \
    }});
 
 /* The below joins as many adjacent EXACTish nodes as possible into a single
@@ -4072,6 +4104,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
     GET_RE_DEBUG_FLAGS_DECL;
 
     PERL_ARGS_ASSERT_STUDY_CHUNK;
+    RExC_study_started= 1;
 
 
     if ( depth == 0 ) {
@@ -4086,9 +4119,8 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
     );
     DEBUG_OPTIMISE_MORE_r(
     {
-        PerlIO_printf(Perl_debug_log,
-            "%*sstudy_chunk stopparen=%ld recursed_count=%lu depth=%lu recursed_depth=%lu scan=%p last=%p",
-            (int)(depth*2), "", (long)stopparen,
+        Perl_re_indentf( aTHX_  "study_chunk stopparen=%ld recursed_count=%lu depth=%lu recursed_depth=%lu scan=%p last=%p",
+            depth, (long)stopparen,
             (unsigned long)RExC_study_chunk_recursed_count,
             (unsigned long)depth, (unsigned long)recursed_depth,
             scan,
@@ -4107,16 +4139,16 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                    (( j - 1 ) * RExC_study_chunk_recursed_bytes), i)
                         )
                     ) {
-                        PerlIO_printf(Perl_debug_log," %d",(int)i);
+                        Perl_re_printf( aTHX_ " %d",(int)i);
                         break;
                     }
                 }
                 if ( j + 1 < recursed_depth ) {
-                    PerlIO_printf(Perl_debug_log, ",");
+                    Perl_re_printf( aTHX_  ",");
                 }
             }
         }
-        PerlIO_printf(Perl_debug_log,"\n");
+        Perl_re_printf( aTHX_ "\n");
     }
     );
     while ( scan && OP(scan) != END && scan < last ){
@@ -4129,9 +4161,10 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
         DEBUG_PEEP("Peep", scan, depth);
 
 
-        /* The reason we do this here we need to deal with things like /(?:f)(?:o)(?:o)/
-         * which cant be dealt with by the normal EXACT parsing code, as each (?:..) is handled
-         * by a different invocation of reg() -- Yves
+        /* The reason we do this here is that we need to deal with things like
+         * /(?:f)(?:o)(?:o)/ which cant be dealt with by the normal EXACT
+         * parsing code, as each (?:..) is handled by a different invocation of
+         * reg() -- Yves
          */
         JOIN_EXACT(scan,&min_subtract, &unfolded_multi_char, 0);
 
@@ -4392,8 +4425,8 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
                         DEBUG_TRIE_COMPILE_r({
                             regprop(RExC_rx, RExC_mysv, tail, NULL, pRExC_state);
-                            PerlIO_printf( Perl_debug_log, "%*s%s %"UVuf":%s\n",
-                              (int)depth * 2 + 2, "",
+                            Perl_re_indentf( aTHX_  "%s %"UVuf":%s\n",
+                              depth+1,
                               "Looking for TRIE'able sequences. Tail node is ",
                               (UV)(tail - RExC_emit_start),
                               SvPV_nolen_const( RExC_mysv )
@@ -4484,20 +4517,20 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 
                             DEBUG_TRIE_COMPILE_r({
                                 regprop(RExC_rx, RExC_mysv, cur, NULL, pRExC_state);
-                                PerlIO_printf( Perl_debug_log, "%*s- %d:%s (%d)",
-                                   (int)depth * 2 + 2,"",
+                                Perl_re_indentf( aTHX_  "- %d:%s (%d)",
+                                   depth+1,
                                    REG_NODE_NUM(cur), SvPV_nolen_const( RExC_mysv ), REG_NODE_NUM(cur) );
 
                                 regprop(RExC_rx, RExC_mysv, noper, NULL, pRExC_state);
-                                PerlIO_printf( Perl_debug_log, " -> %d:%s",
+                                Perl_re_printf( aTHX_  " -> %d:%s",
                                     REG_NODE_NUM(noper), SvPV_nolen_const(RExC_mysv));
 
                                 if ( noper_next ) {
                                   regprop(RExC_rx, RExC_mysv, noper_next, NULL, pRExC_state);
-                                  PerlIO_printf( Perl_debug_log,"\t=> %d:%s\t",
+                                  Perl_re_printf( aTHX_ "\t=> %d:%s\t",
                                     REG_NODE_NUM(noper_next), SvPV_nolen_const(RExC_mysv));
                                 }
-                                PerlIO_printf( Perl_debug_log, "(First==%d,Last==%d,Cur==%d,tt==%s,ntt==%s,nntt==%s)\n",
+                                Perl_re_printf( aTHX_  "(First==%d,Last==%d,Cur==%d,tt==%s,ntt==%s,nntt==%s)\n",
                                    REG_NODE_NUM(first), REG_NODE_NUM(last), REG_NODE_NUM(cur),
                                   PL_reg_name[trietype], PL_reg_name[noper_trietype], PL_reg_name[noper_next_trietype]
                                );
@@ -4513,7 +4546,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                         || ( trietype == noper_trietype )
                                   )
 #ifdef NOJUMPTRIE
-                                  && noper_next == tail
+                                  && noper_next >= tail
 #endif
                                   && count < U16_MAX)
                             {
@@ -4573,7 +4606,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                 }
                                 if ( noper_trietype
 #ifdef NOJUMPTRIE
-                                     && noper_next == tail
+                                     && noper_next >= tail
 #endif
                                 ){
                                     /* noper is triable, so we can start a new
@@ -4593,11 +4626,9 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                         } /* loop over branches */
                         DEBUG_TRIE_COMPILE_r({
                             regprop(RExC_rx, RExC_mysv, cur, NULL, pRExC_state);
-                            PerlIO_printf( Perl_debug_log,
-                              "%*s- %s (%d) <SCAN FINISHED> ",
-                              (int)depth * 2 + 2,
-                              "", SvPV_nolen_const( RExC_mysv ),REG_NODE_NUM(cur));
-                            PerlIO_printf( Perl_debug_log, "(First==%d, Last==%d, Cur==%d, tt==%s)\n",
+                            Perl_re_indentf( aTHX_  "- %s (%d) <SCAN FINISHED> ",
+                              depth+1, SvPV_nolen_const( RExC_mysv ),REG_NODE_NUM(cur));
+                            Perl_re_printf( aTHX_  "(First==%d, Last==%d, Cur==%d, tt==%s)\n",
                                REG_NODE_NUM(first), REG_NODE_NUM(last), REG_NODE_NUM(cur),
                                PL_reg_name[trietype]
                             );
@@ -4618,7 +4649,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                      depth==0 ) {
                                     flags |= SCF_TRIE_RESTUDY;
                                     if ( startbranch == first
-                                         && scan == tail )
+                                         && scan >= tail )
                                     {
                                         RExC_seen &=~REG_TOP_LEVEL_BRANCHES_SEEN;
                                     }
@@ -4637,9 +4668,9 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
                                      * turn it into a plain NOTHING op. */
                                     DEBUG_TRIE_COMPILE_r({
                                         regprop(RExC_rx, RExC_mysv, cur, NULL, pRExC_state);
-                                        PerlIO_printf( Perl_debug_log,
-                                          "%*s- %s (%d) <NOTHING BRANCH SEQUENCE>\n", (int)depth * 2 + 2,
-                                          "", SvPV_nolen_const( RExC_mysv ),REG_NODE_NUM(cur));
+                                        Perl_re_indentf( aTHX_  "- %s (%d) <NOTHING BRANCH SEQUENCE>\n",
+                                          depth+1,
+                                          SvPV_nolen_const( RExC_mysv ),REG_NODE_NUM(cur));
 
                                     });
                                     OP(startbranch)= NOTHING;
@@ -5227,13 +5258,13 @@ 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=%"UVuf" deltanext=%"UVuf
+Perl_re_printf( aTHX_  "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=%"UVuf" RHS=%"UVuf"\n",
+Perl_re_printf( aTHX_  "LHS=%"UVuf" RHS=%"UVuf"\n",
     (UV)(-counted * deltanext + (minnext + deltanext) * maxcount
           - minnext * mincount), (UV)(SSize_t_MAX - data->pos_delta));
 #endif
@@ -5871,15 +5902,10 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVuf" RHS=%"UVuf"\n",
        /* Else: zero-length, ignore. */
        scan = regnext(scan);
     }
-    /* If we are exiting a recursion we can unset its recursed bit
-     * and allow ourselves to enter it again - no danger of an
-     * infinite loop there.
-    if (stopparen > -1 && recursed) {
-       DEBUG_STUDYDATA("unset:", data,depth);
-        PAREN_UNSET( recursed, stopparen);
-    }
-    */
+
+  finish:
     if (frame) {
+        /* we need to unwind recursion. */
         depth = depth - 1;
 
         DEBUG_STUDYDATA("frame-end:",data,depth);
@@ -5896,7 +5922,6 @@ PerlIO_printf(Perl_debug_log, "LHS=%"UVuf" RHS=%"UVuf"\n",
         goto fake_study_recurse;
     }
 
-  finish:
     assert(!frame);
     DEBUG_STUDYDATA("pre-fin:",data,depth);
 
@@ -6047,7 +6072,7 @@ Perl_pregcomp(pTHX_ SV * const pattern, const U32 flags)
 
     /* Dispatch a request to compile a regexp to correct regexp engine. */
     DEBUG_COMPILE_r({
-       PerlIO_printf(Perl_debug_log, "Using engine %"UVxf"\n",
+        Perl_re_printf( aTHX_  "Using engine %"UVxf"\n",
                        PTR2UV(eng));
     });
     return CALLREGCOMP_ENG(eng, pattern, flags);
@@ -6092,7 +6117,7 @@ S_pat_upgrade_to_utf8(pTHX_ RExC_state_t * const pRExC_state,
     bool do_end = 0;
     GET_RE_DEBUG_FLAGS_DECL;
 
-    DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
+    DEBUG_PARSE_r(Perl_re_printf( aTHX_
         "UTF8 mismatch! Converting to utf8 for resizing and compile\n"));
 
     Newx(dst, *plen_p * 2 + 1, U8);
@@ -6460,7 +6485,7 @@ S_compile_runtime_code(pTHX_ RExC_state_t * const pRExC_state,
            *p++ = 'x';
        *p++ = '\0';
        DEBUG_COMPILE_r({
-           PerlIO_printf(Perl_debug_log,
+            Perl_re_printf( aTHX_
                "%sre-parsing pattern for runtime code:%s %s\n",
                PL_colors[4],PL_colors[5],newpat);
        });
@@ -6795,7 +6820,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
 
     }
 
-    DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
+    DEBUG_PARSE_r(Perl_re_printf( aTHX_
         "Assembling pattern from %d elements%s\n", pat_count,
             orig_rx_flags & RXf_SPLIT ? " for split" : ""));
 
@@ -6824,7 +6849,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                 *is_bare_re = TRUE;
             SvREFCNT_inc(re);
             Safefree(pRExC_state->code_blocks);
-            DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
+            DEBUG_PARSE_r(Perl_re_printf( aTHX_
                 "Precompiled pattern%s\n",
                     orig_rx_flags & RXf_SPLIT ? " for split" : ""));
 
@@ -6855,6 +6880,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     RExC_contains_locale = 0;
     RExC_contains_i = 0;
     RExC_strict = cBOOL(pm_flags & RXf_PMf_STRICT);
+    RExC_study_started = 0;
     pRExC_state->runtime_code_qr = NULL;
     RExC_frame_head= NULL;
     RExC_frame_last= NULL;
@@ -6867,7 +6893,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     DEBUG_COMPILE_r({
             SV *dsv= sv_newmortal();
             RE_PV_QUOTED_DECL(s, RExC_utf8, dsv, exp, plen, 60);
-            PerlIO_printf(Perl_debug_log, "%sCompiling REx%s %s\n",
+            Perl_re_printf( aTHX_  "%sCompiling REx%s %s\n",
                           PL_colors[4],PL_colors[5],s);
         });
 
@@ -6983,7 +7009,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     assert(*RExC_end == '\0');
 
     DEBUG_PARSE_r(
-       PerlIO_printf(Perl_debug_log, "Starting first pass (sizing)\n");
+        Perl_re_printf( aTHX_  "Starting first pass (sizing)\n");
         RExC_lastnum=0;
         RExC_lastparse=NULL;
     );
@@ -7013,7 +7039,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
                                     pRExC_state->num_code_blocks);
             }
             else {
-                DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log,
+                DEBUG_PARSE_r(Perl_re_printf( aTHX_
                 "Need to redo pass 1\n"));
             }
 
@@ -7025,7 +7051,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
        SvLEN_set(code_blocksv,0); /* no you can't have it, sv_clear */
 
     DEBUG_PARSE_r({
-        PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
             "Required size %"IVdf" nodes\n"
             "Starting second pass (creation)\n",
             (IV)RExC_size);
@@ -7163,7 +7189,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     /* Useful during FAIL. */
 #ifdef RE_TRACK_PATTERN_OFFSETS
     Newxz(ri->u.offsets, 2*RExC_size+1, U32); /* MJD 20001228 */
-    DEBUG_OFFSETS_r(PerlIO_printf(Perl_debug_log,
+    DEBUG_OFFSETS_r(Perl_re_printf( aTHX_
                           "%s %"UVuf" bytes for offset annotations.\n",
                           ri->u.offsets ? "Got" : "Couldn't get",
                           (UV)((2*RExC_size+1) * sizeof(U32))));
@@ -7188,7 +7214,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     /* setup various meta data about recursion, this all requires
      * RExC_npar to be correctly set, and a bit later on we clear it */
     if (RExC_seen & REG_RECURSE_SEEN) {
-        DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+        DEBUG_OPTIMISE_MORE_r(Perl_re_printf( aTHX_
             "%*s%*s Setting up open/close parens\n",
                   22, "|    |", (int)(0 * 2 + 1), ""));
 
@@ -7221,7 +7247,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
         Perl_croak(aTHX_ "panic: reg returned NULL to re_op_compile for generation pass, flags=%#"UVxf"", (UV) flags);
     }
     DEBUG_OPTIMISE_r(
-        PerlIO_printf(Perl_debug_log, "Starting post parse optimization\n");
+        Perl_re_printf( aTHX_  "Starting post parse optimization\n");
     );
 
     /* XXXX To minimize changes to RE engine we always allocate
@@ -7250,7 +7276,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
         copyRExC_state = RExC_state;
     } else {
         U32 seen=RExC_seen;
-        DEBUG_OPTIMISE_r(PerlIO_printf(Perl_debug_log,"Restudying\n"));
+        DEBUG_OPTIMISE_r(Perl_re_printf( aTHX_ "Restudying\n"));
 
         RExC_state = copyRExC_state;
         if (seen & REG_TOP_LEVEL_BRANCHES_SEEN)
@@ -7384,12 +7410,12 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
 #ifdef TRIE_STUDY_OPT
        DEBUG_PARSE_r(
            if (!restudied)
-               PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
+                Perl_re_printf( aTHX_  "first at %"IVdf"\n",
                              (IV)(first - scan + 1))
         );
 #else
        DEBUG_PARSE_r(
-           PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
+            Perl_re_printf( aTHX_  "first at %"IVdf"\n",
                (IV)(first - scan + 1))
         );
 #endif
@@ -7518,7 +7544,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
            r->intflags &= ~PREGf_SKIP; /* Used in find_byclass(). */
            DEBUG_COMPILE_r({ SV *sv = sv_newmortal();
                       regprop(r, sv, (regnode*)data.start_class, NULL, pRExC_state);
-                     PerlIO_printf(Perl_debug_log,
+                      Perl_re_printf( aTHX_
                                    "synthetic stclass \"%s\".\n",
                                    SvPVX_const(sv));});
             data.start_class = NULL;
@@ -7563,7 +7589,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
        regnode_ssc ch_class;
        SSize_t last_close = 0;
 
-       DEBUG_PARSE_r(PerlIO_printf(Perl_debug_log, "\nMulti Top Level\n"));
+        DEBUG_PARSE_r(Perl_re_printf( aTHX_  "\nMulti Top Level\n"));
 
        scan = ri->program + 1;
        ssc_init(pRExC_state, &ch_class);
@@ -7598,7 +7624,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
            r->intflags &= ~PREGf_SKIP; /* Used in find_byclass(). */
            DEBUG_COMPILE_r({ SV* sv = sv_newmortal();
                       regprop(r, sv, (regnode*)data.start_class, NULL, pRExC_state);
-                     PerlIO_printf(Perl_debug_log,
+                      Perl_re_printf( aTHX_
                                    "synthetic stclass \"%s\".\n",
                                    SvPVX_const(sv));});
             data.start_class = NULL;
@@ -7616,7 +7642,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     /* Guard against an embedded (?=) or (?<=) with a longer minlen than
        the "real" pattern. */
     DEBUG_OPTIMISE_r({
-        PerlIO_printf(Perl_debug_log,"minlen: %"IVdf" r->minlen:%"IVdf" maxlen:%"IVdf"\n",
+        Perl_re_printf( aTHX_ "minlen: %"IVdf" r->minlen:%"IVdf" maxlen:%"IVdf"\n",
                       (IV)minlen, (IV)r->minlen, (IV)RExC_maxlen);
     });
     r->minlenret = minlen;
@@ -7710,12 +7736,12 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     Newxz(r->offs, RExC_npar, regexp_paren_pair);
     /* assume we don't need to swap parens around before we match */
     DEBUG_TEST_r({
-        PerlIO_printf(Perl_debug_log,"study_chunk_recursed_count: %lu\n",
+        Perl_re_printf( aTHX_ "study_chunk_recursed_count: %lu\n",
             (unsigned long)RExC_study_chunk_recursed_count);
     });
     DEBUG_DUMP_r({
         DEBUG_RExC_seen();
-        PerlIO_printf(Perl_debug_log,"Final program:\n");
+        Perl_re_printf( aTHX_ "Final program:\n");
         regdump(r);
     });
 #ifdef RE_TRACK_PATTERN_OFFSETS
@@ -7723,14 +7749,14 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
         const STRLEN len = ri->u.offsets[0];
         STRLEN i;
         GET_RE_DEBUG_FLAGS_DECL;
-        PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                       "Offsets: [%"UVuf"]\n\t", (UV)ri->u.offsets[0]);
         for (i = 1; i <= len; i++) {
             if (ri->u.offsets[i*2-1] || ri->u.offsets[i*2])
-                PerlIO_printf(Perl_debug_log, "%"UVuf":%"UVuf"[%"UVuf"] ",
+                Perl_re_printf( aTHX_  "%"UVuf":%"UVuf"[%"UVuf"] ",
                 (UV)i, (UV)ri->u.offsets[i*2-1], (UV)ri->u.offsets[i*2]);
             }
-        PerlIO_printf(Perl_debug_log, "\n");
+        Perl_re_printf( aTHX_  "\n");
     });
 #endif
 
@@ -8248,7 +8274,7 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
 #define DEBUG_PARSE_MSG(funcname)     DEBUG_PARSE_r({           \
     int num;                                                    \
     if (RExC_lastparse!=RExC_parse) {                           \
-        PerlIO_printf(Perl_debug_log, "%s",                     \
+        Perl_re_printf( aTHX_  "%s",                                        \
             Perl_pv_pretty(aTHX_ RExC_mysv1, RExC_parse,        \
                 RExC_end - RExC_parse, 16,                      \
                 "", "",                                         \
@@ -8260,17 +8286,17 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
             )                                                   \
         );                                                      \
     } else                                                      \
-        PerlIO_printf(Perl_debug_log,"%16s","");                \
+        Perl_re_printf( aTHX_ "%16s","");                                   \
                                                                 \
     if (SIZE_ONLY)                                              \
        num = RExC_size + 1;                                     \
     else                                                        \
        num=REG_NODE_NUM(RExC_emit);                             \
     if (RExC_lastnum!=num)                                      \
-       PerlIO_printf(Perl_debug_log,"|%4d",num);                \
+       Perl_re_printf( aTHX_ "|%4d",num);                                   \
     else                                                        \
-       PerlIO_printf(Perl_debug_log,"|%4s","");                 \
-    PerlIO_printf(Perl_debug_log,"|%*s%-4s",                    \
+       Perl_re_printf( aTHX_ "|%4s","");                                    \
+    Perl_re_printf( aTHX_ "|%*s%-4s",                                       \
         (int)((depth*2)), "",                                   \
         (funcname)                                              \
     );                                                          \
@@ -8282,11 +8308,11 @@ S_reg_scan_name(pTHX_ RExC_state_t *pRExC_state, U32 flags)
 
 #define DEBUG_PARSE(funcname)     DEBUG_PARSE_r({           \
     DEBUG_PARSE_MSG((funcname));                            \
-    PerlIO_printf(Perl_debug_log,"%4s","\n");               \
+    Perl_re_printf( aTHX_ "%4s","\n");                                  \
 })
-#define DEBUG_PARSE_FMT(funcname,fmt,args)     DEBUG_PARSE_r({           \
+#define DEBUG_PARSE_FMT(funcname,fmt,args)     DEBUG_PARSE_r({\
     DEBUG_PARSE_MSG((funcname));                            \
-    PerlIO_printf(Perl_debug_log,fmt "\n",args);               \
+    Perl_re_printf( aTHX_ fmt "\n",args);                               \
 })
 
 /* This section of code defines the inversion list object and its methods.  The
@@ -10205,8 +10231,9 @@ S_parse_lparen_question_flags(pTHX_ RExC_state_t *pRExC_state)
                 if (RExC_flags & RXf_PMf_FOLD) {
                     RExC_contains_i = 1;
                 }
-                if (PASS2) {
-                    STD_PMMOD_FLAGS_PARSE_X_WARN(x_mod_count);
+
+                if (UNLIKELY((x_mod_count) > 1)) {
+                    vFAIL("Only one /x regex modifier is allowed");
                 }
                 return;
                 /*NOTREACHED*/
@@ -10719,7 +10746,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                        vFAIL("Reference to nonexistent group");
                    }
                    RExC_recurse_count++;
-                   DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+                    DEBUG_OPTIMISE_MORE_r(Perl_re_printf( aTHX_
                         "%*s%*s Recurse #%"UVuf" to %"IVdf"\n",
                               22, "|    |", (int)(depth * 2 + 1), "",
                               (UV)ARG(ret), (IV)ARG2L(ret)));
@@ -11032,7 +11059,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                    RExC_nestroot = parno;
                 if (RExC_open_parens && !RExC_open_parens[parno])
                {
-                   DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+                    DEBUG_OPTIMISE_MORE_r(Perl_re_printf( aTHX_
                         "%*s%*s Setting open paren #%"IVdf" to %d\n",
                         22, "|    |", (int)(depth * 2 + 1), "",
                        (IV)parno, REG_NODE_NUM(ret)));
@@ -11126,7 +11153,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
        case 1: case 2:
            ender = reganode(pRExC_state, CLOSE, parno);
             if ( RExC_close_parens ) {
-               DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+                DEBUG_OPTIMISE_MORE_r(Perl_re_printf( aTHX_
                         "%*s%*s Setting close paren #%"IVdf" to %d\n",
                         22, "|    |", (int)(depth * 2 + 1), "", (IV)parno, REG_NODE_NUM(ender)));
                 RExC_close_parens[parno]= ender;
@@ -11151,7 +11178,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                 assert(!RExC_end_op); /* there can only be one! */
                 RExC_end_op = ender;
                 if (RExC_close_parens) {
-                    DEBUG_OPTIMISE_MORE_r(PerlIO_printf(Perl_debug_log,
+                    DEBUG_OPTIMISE_MORE_r(Perl_re_printf( aTHX_
                         "%*s%*s Setting close paren #0 (END) to %d\n",
                         22, "|    |", (int)(depth * 2 + 1), "", REG_NODE_NUM(ender)));
 
@@ -11164,7 +11191,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
             DEBUG_PARSE_MSG("lsbr");
             regprop(RExC_rx, RExC_mysv1, lastbr, NULL, pRExC_state);
             regprop(RExC_rx, RExC_mysv2, ender, NULL, pRExC_state);
-            PerlIO_printf(Perl_debug_log, "~ tying lastbr %s (%"IVdf") to ender %s (%"IVdf") offset %"IVdf"\n",
+            Perl_re_printf( aTHX_  "~ tying lastbr %s (%"IVdf") to ender %s (%"IVdf") offset %"IVdf"\n",
                           SvPV_nolen_const(RExC_mysv1),
                           (IV)REG_NODE_NUM(lastbr),
                           SvPV_nolen_const(RExC_mysv2),
@@ -11203,7 +11230,7 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp,U32 depth)
                     DEBUG_PARSE_MSG("NADA");
                     regprop(RExC_rx, RExC_mysv1, ret, NULL, pRExC_state);
                     regprop(RExC_rx, RExC_mysv2, ender, NULL, pRExC_state);
-                    PerlIO_printf(Perl_debug_log, "~ converting ret %s (%"IVdf") to ender %s (%"IVdf") offset %"IVdf"\n",
+                    Perl_re_printf( aTHX_  "~ converting ret %s (%"IVdf") to ender %s (%"IVdf") offset %"IVdf"\n",
                                   SvPV_nolen_const(RExC_mysv1),
                                   (IV)REG_NODE_NUM(ret),
                                   SvPV_nolen_const(RExC_mysv2),
@@ -13161,14 +13188,13 @@ S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
                    } /* End of switch on '\' */
                    break;
                case '{':
-                   /* Currently we don't warn when the lbrace is at the start
+                   /* Currently we don't care if the lbrace is at the start
                     * of a construct.  This catches it in the middle of a
                     * literal string, or when it's 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");
+                   if (len || (p > RExC_start && isALPHA_A(*(p -1)))) {
+                        RExC_parse = p + 1;
+                       vFAIL("Unescaped left brace in regex is illegal");
                    }
                    /*FALLTHROUGH*/
                default:    /* A literal character */
@@ -14520,7 +14546,9 @@ S_handle_regex_sets(pTHX_ RExC_state_t *pRExC_state, SV** return_invlist,
                                        'stack' of where the undealt-with left
                                        parens would be if they were actually
                                        put there */
-    IV fence = 0;                   /* Position of where most recent undealt-
+    /* The 'VOL' (expanding to 'volatile') is a workaround for an optimiser bug
+     * in Solaris Studio 12.3. See RT #127455 */
+    VOL IV fence = 0;               /* Position of where most recent undealt-
                                        with left paren in stack is; -1 if none.
                                      */
     STRLEN len;                     /* Temporary */
@@ -15124,6 +15152,7 @@ redo_curchar:
              * stack, we have to check if it is a !.  But first, the code above
              * may have altered the stack in the time since we earlier set
              * 'top_index'.  */
+
             top_index = av_tindex_nomg(stack);
             if (top_index - fence >= 0) {
                 /* If the top entry on the stack is an operator, it had better
@@ -15944,6 +15973,10 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
                     SAVEFREEPV(name);
                     if (FOLD) {
                         lookup_name = savepv(Perl_form(aTHX_ "__%s_i", name));
+
+                        /* The function call just below that uses this can fail
+                         * to return, leaking memory if we don't do this */
+                        SAVEFREEPV(lookup_name);
                     }
 
                     /* Look up the property name, and get its swash and
@@ -15959,9 +15992,6 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
                                              NULL, /* No inversion list */
                                              &swash_init_flags
                                             );
-                    if (lookup_name) {
-                        Safefree(lookup_name);
-                    }
                     if (! swash || ! (invlist = _get_swash_invlist(swash))) {
                         HV* curpkg = (IN_PERL_COMPILETIME)
                                       ? PL_curstash
@@ -18209,7 +18239,9 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
        RExC_size += size;
        return;
     }
-
+    assert(!RExC_study_started); /* I believe we should never use reginsert once we have started
+                                    studying. If this is wrong then we need to adjust RExC_recurse
+                                    below like we do with RExC_open_parens/RExC_close_parens. */
     src = RExC_emit;
     RExC_emit += size;
     dst = RExC_emit;
@@ -18220,7 +18252,10 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
          * iow it is 1 more than the number of parens seen in
          * the pattern so far. */
         for ( paren=0 ; paren < RExC_npar ; paren++ ) {
-            if ( RExC_open_parens[paren] >= opnd ) {
+            /* note, RExC_open_parens[0] is the start of the
+             * regex, it can't move. RExC_close_parens[0] is the end
+             * of the regex, it *can* move. */
+            if ( paren && RExC_open_parens[paren] >= opnd ) {
                 /*DEBUG_PARSE_FMT("open"," - %d",size);*/
                 RExC_open_parens[paren] += size;
             } else {
@@ -18308,7 +18343,7 @@ S_regtail(pTHX_ RExC_state_t * pRExC_state,
         DEBUG_PARSE_r({
             DEBUG_PARSE_MSG((scan==p ? "tail" : ""));
             regprop(RExC_rx, RExC_mysv, scan, NULL, pRExC_state);
-            PerlIO_printf(Perl_debug_log, "~ %s (%d) %s %s\n",
+            Perl_re_printf( aTHX_  "~ %s (%d) %s %s\n",
                 SvPV_nolen_const(RExC_mysv), REG_NODE_NUM(scan),
                     (temp == NULL ? "->" : ""),
                     (temp == NULL ? PL_reg_name[OP(val)] : "")
@@ -18398,7 +18433,7 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p,
         DEBUG_PARSE_r({
             DEBUG_PARSE_MSG((scan==p ? "tsdy" : ""));
             regprop(RExC_rx, RExC_mysv, scan, NULL, pRExC_state);
-            PerlIO_printf(Perl_debug_log, "~ %s (%d) -> %s\n",
+            Perl_re_printf( aTHX_  "~ %s (%d) -> %s\n",
                 SvPV_nolen_const(RExC_mysv),
                 REG_NODE_NUM(scan),
                 PL_reg_name[exact]);
@@ -18410,7 +18445,7 @@ S_regtail_study(pTHX_ RExC_state_t *pRExC_state, regnode *p,
     DEBUG_PARSE_r({
         DEBUG_PARSE_MSG("");
         regprop(RExC_rx, RExC_mysv, val, NULL, pRExC_state);
-        PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                       "~ attach to %s (%"IVdf") offset to %"IVdf"\n",
                      SvPV_nolen_const(RExC_mysv),
                      (IV)REG_NODE_NUM(val),
@@ -18444,15 +18479,15 @@ S_regdump_intflags(pTHX_ const char *lead, const U32 flags)
     for (bit=0; bit<REG_INTFLAGS_NAME_SIZE; bit++) {
         if (flags & (1<<bit)) {
             if (!set++ && lead)
-                PerlIO_printf(Perl_debug_log, "%s",lead);
-            PerlIO_printf(Perl_debug_log, "%s ",PL_reg_intflags_name[bit]);
+                Perl_re_printf( aTHX_  "%s",lead);
+            Perl_re_printf( aTHX_  "%s ",PL_reg_intflags_name[bit]);
         }
     }
     if (lead)  {
         if (set)
-            PerlIO_printf(Perl_debug_log, "\n");
+            Perl_re_printf( aTHX_  "\n");
         else
-            PerlIO_printf(Perl_debug_log, "%s[none-set]\n",lead);
+            Perl_re_printf( aTHX_  "%s[none-set]\n",lead);
     }
 }
 
@@ -18471,37 +18506,37 @@ S_regdump_extflags(pTHX_ const char *lead, const U32 flags)
                continue;
            }
             if (!set++ && lead)
-                PerlIO_printf(Perl_debug_log, "%s",lead);
-            PerlIO_printf(Perl_debug_log, "%s ",PL_reg_extflags_name[bit]);
+                Perl_re_printf( aTHX_  "%s",lead);
+            Perl_re_printf( aTHX_  "%s ",PL_reg_extflags_name[bit]);
         }
     }
     if ((cs = get_regex_charset(flags)) != REGEX_DEPENDS_CHARSET) {
             if (!set++ && lead) {
-                PerlIO_printf(Perl_debug_log, "%s",lead);
+                Perl_re_printf( aTHX_  "%s",lead);
             }
             switch (cs) {
                 case REGEX_UNICODE_CHARSET:
-                    PerlIO_printf(Perl_debug_log, "UNICODE");
+                    Perl_re_printf( aTHX_  "UNICODE");
                     break;
                 case REGEX_LOCALE_CHARSET:
-                    PerlIO_printf(Perl_debug_log, "LOCALE");
+                    Perl_re_printf( aTHX_  "LOCALE");
                     break;
                 case REGEX_ASCII_RESTRICTED_CHARSET:
-                    PerlIO_printf(Perl_debug_log, "ASCII-RESTRICTED");
+                    Perl_re_printf( aTHX_  "ASCII-RESTRICTED");
                     break;
                 case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
-                    PerlIO_printf(Perl_debug_log, "ASCII-MORE_RESTRICTED");
+                    Perl_re_printf( aTHX_  "ASCII-MORE_RESTRICTED");
                     break;
                 default:
-                    PerlIO_printf(Perl_debug_log, "UNKNOWN CHARACTER SET");
+                    Perl_re_printf( aTHX_  "UNKNOWN CHARACTER SET");
                     break;
             }
     }
     if (lead)  {
         if (set)
-            PerlIO_printf(Perl_debug_log, "\n");
+            Perl_re_printf( aTHX_  "\n");
         else
-            PerlIO_printf(Perl_debug_log, "%s[none-set]\n",lead);
+            Perl_re_printf( aTHX_  "%s[none-set]\n",lead);
     }
 }
 #endif
@@ -18523,14 +18558,14 @@ Perl_regdump(pTHX_ const regexp *r)
     if (r->anchored_substr) {
        RE_PV_QUOTED_DECL(s, 0, dsv, SvPVX_const(r->anchored_substr),
            RE_SV_DUMPLEN(r->anchored_substr), 30);
-       PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                      "anchored %s%s at %"IVdf" ",
                      s, RE_SV_TAIL(r->anchored_substr),
                      (IV)r->anchored_offset);
     } else if (r->anchored_utf8) {
        RE_PV_QUOTED_DECL(s, 1, dsv, SvPVX_const(r->anchored_utf8),
            RE_SV_DUMPLEN(r->anchored_utf8), 30);
-       PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                      "anchored utf8 %s%s at %"IVdf" ",
                      s, RE_SV_TAIL(r->anchored_utf8),
                      (IV)r->anchored_offset);
@@ -18538,55 +18573,55 @@ Perl_regdump(pTHX_ const regexp *r)
     if (r->float_substr) {
        RE_PV_QUOTED_DECL(s, 0, dsv, SvPVX_const(r->float_substr),
            RE_SV_DUMPLEN(r->float_substr), 30);
-       PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                      "floating %s%s at %"IVdf"..%"UVuf" ",
                      s, RE_SV_TAIL(r->float_substr),
                      (IV)r->float_min_offset, (UV)r->float_max_offset);
     } else if (r->float_utf8) {
        RE_PV_QUOTED_DECL(s, 1, dsv, SvPVX_const(r->float_utf8),
            RE_SV_DUMPLEN(r->float_utf8), 30);
-       PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                      "floating utf8 %s%s at %"IVdf"..%"UVuf" ",
                      s, RE_SV_TAIL(r->float_utf8),
                      (IV)r->float_min_offset, (UV)r->float_max_offset);
     }
     if (r->check_substr || r->check_utf8)
-       PerlIO_printf(Perl_debug_log,
+        Perl_re_printf( aTHX_
                      (const char *)
                      (r->check_substr == r->float_substr
                       && r->check_utf8 == r->float_utf8
                       ? "(checking floating" : "(checking anchored"));
     if (r->intflags & PREGf_NOSCAN)
-       PerlIO_printf(Perl_debug_log, " noscan");
+        Perl_re_printf( aTHX_  " noscan");
     if (r->extflags & RXf_CHECK_ALL)
-       PerlIO_printf(Perl_debug_log, " isall");
+        Perl_re_printf( aTHX_  " isall");
     if (r->check_substr || r->check_utf8)
-       PerlIO_printf(Perl_debug_log, ") ");
+        Perl_re_printf( aTHX_  ") ");
 
     if (ri->regstclass) {
         regprop(r, sv, ri->regstclass, NULL, NULL);
-       PerlIO_printf(Perl_debug_log, "stclass %s ", SvPVX_const(sv));
+        Perl_re_printf( aTHX_  "stclass %s ", SvPVX_const(sv));
     }
     if (r->intflags & PREGf_ANCH) {
-       PerlIO_printf(Perl_debug_log, "anchored");
+        Perl_re_printf( aTHX_  "anchored");
         if (r->intflags & PREGf_ANCH_MBOL)
-           PerlIO_printf(Perl_debug_log, "(MBOL)");
+            Perl_re_printf( aTHX_  "(MBOL)");
         if (r->intflags & PREGf_ANCH_SBOL)
-           PerlIO_printf(Perl_debug_log, "(SBOL)");
+            Perl_re_printf( aTHX_  "(SBOL)");
         if (r->intflags & PREGf_ANCH_GPOS)
-           PerlIO_printf(Perl_debug_log, "(GPOS)");
-       (void)PerlIO_putc(Perl_debug_log, ' ');
+            Perl_re_printf( aTHX_  "(GPOS)");
+        Perl_re_printf( aTHX_ " ");
     }
     if (r->intflags & PREGf_GPOS_SEEN)
-       PerlIO_printf(Perl_debug_log, "GPOS:%"UVuf" ", (UV)r->gofs);
+        Perl_re_printf( aTHX_  "GPOS:%"UVuf" ", (UV)r->gofs);
     if (r->intflags & PREGf_SKIP)
-       PerlIO_printf(Perl_debug_log, "plus ");
+        Perl_re_printf( aTHX_  "plus ");
     if (r->intflags & PREGf_IMPLICIT)
-       PerlIO_printf(Perl_debug_log, "implicit ");
-    PerlIO_printf(Perl_debug_log, "minlen %"IVdf" ", (IV)r->minlen);
+        Perl_re_printf( aTHX_  "implicit ");
+    Perl_re_printf( aTHX_  "minlen %"IVdf" ", (IV)r->minlen);
     if (r->extflags & RXf_EVAL_SEEN)
-       PerlIO_printf(Perl_debug_log, "with eval ");
-    PerlIO_printf(Perl_debug_log, "\n");
+        Perl_re_printf( aTHX_  "with eval ");
+    Perl_re_printf( aTHX_  "\n");
     DEBUG_FLAGS_r({
         regdump_extflags("r->extflags: ",r->extflags);
         regdump_intflags("r->intflags: ",r->intflags);
@@ -18993,7 +19028,7 @@ Perl_re_intuit_string(pTHX_ REGEXP * const r)
                      ? prog->check_utf8 : prog->check_substr);
 
            if (!PL_colorset) reginitcolors();
-           PerlIO_printf(Perl_debug_log,
+            Perl_re_printf( aTHX_
                      "%sUsing REx %ssubstr:%s \"%s%.60s%s%s\"\n",
                      PL_colors[4],
                      RX_UTF8(r) ? "utf8 " : "",
@@ -19174,7 +19209,7 @@ Perl_regfree_internal(pTHX_ REGEXP * const rx)
            SV *dsv= sv_newmortal();
             RE_PV_QUOTED_DECL(s, RX_UTF8(rx),
                 dsv, RX_PRECOMP(rx), RX_PRELEN(rx), 60);
-            PerlIO_printf(Perl_debug_log,"%sFreeing REx:%s %s\n",
+            Perl_re_printf( aTHX_ "%sFreeing REx:%s %s\n",
                 PL_colors[4],PL_colors[5],s);
         }
     });
@@ -20008,14 +20043,7 @@ S_put_charclass_bitmap_innards(pTHX_ SV *sv,
             /* And this flag for matching all non-ASCII 0xFF and below */
             if (flags & ANYOF_SHARED_d_MATCHES_ALL_NON_UTF8_NON_ASCII_non_d_WARN_SUPER)
             {
-                if (invert) {
-                    not_utf8 = _new_invlist(0);
-                }
-                else {
-                    not_utf8 = invlist_clone(PL_UpperLatin1);
-                }
-                inverting_allowed = FALSE;  /* XXX needs more work to be able
-                                               to allow this */
+                not_utf8 = invlist_clone(PL_UpperLatin1);
             }
         }
         else if (OP(node) == ANYOFL) {
@@ -20117,6 +20145,7 @@ S_put_charclass_bitmap_innards(pTHX_ SV *sv,
          * conditional code points, so that when inverted, they will be gone
          * from it */
         _invlist_union(only_utf8, invlist, &invlist);
+        _invlist_union(not_utf8, invlist, &invlist);
         _invlist_union(only_utf8_locale, invlist, &invlist);
         _invlist_invert(invlist);
         _invlist_intersection(invlist, PL_InBitmap, &invlist);
@@ -20169,11 +20198,11 @@ S_put_charclass_bitmap_innards(pTHX_ SV *sv,
     return SvCUR(sv) > orig_sv_cur;
 }
 
-#define CLEAR_OPTSTART \
+#define CLEAR_OPTSTART                                                       \
     if (optstart) STMT_START {                                               \
-        DEBUG_OPTIMISE_r(PerlIO_printf(Perl_debug_log,                       \
+        DEBUG_OPTIMISE_r(Perl_re_printf( aTHX_                                           \
                               " (%"IVdf" nodes)\n", (IV)(node - optstart))); \
-       optstart=NULL;                                                       \
+        optstart=NULL;                                                       \
     } STMT_END
 
 #define DUMPUNTIL(b,e)                                                       \
@@ -20195,7 +20224,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
     PERL_ARGS_ASSERT_DUMPUNTIL;
 
 #ifdef DEBUG_DUMPUNTIL
-    PerlIO_printf(Perl_debug_log, "--- %d : %d - %d - %d\n",indent,node-start,
+    Perl_re_printf( aTHX_  "--- %d : %d - %d - %d\n",indent,node-start,
         last ? last-start : 0,plast ? plast-start : 0);
 #endif
 
@@ -20221,18 +20250,18 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
            CLEAR_OPTSTART;
 
         regprop(r, sv, node, NULL, NULL);
-       PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
+        Perl_re_printf( aTHX_  "%4"IVdf":%*s%s", (IV)(node - start),
                      (int)(2*indent + 1), "", SvPVX_const(sv));
 
         if (OP(node) != OPTIMIZED) {
             if (next == NULL)          /* Next ptr. */
-                PerlIO_printf(Perl_debug_log, " (0)");
+                Perl_re_printf( aTHX_  " (0)");
             else if (PL_regkind[(U8)op] == BRANCH
                      && PL_regkind[OP(next)] != BRANCH )
-                PerlIO_printf(Perl_debug_log, " (FAIL)");
+                Perl_re_printf( aTHX_  " (FAIL)");
             else
-                PerlIO_printf(Perl_debug_log, " (%"IVdf")", (IV)(next - start));
-            (void)PerlIO_putc(Perl_debug_log, '\n');
+                Perl_re_printf( aTHX_  " (%"IVdf")", (IV)(next - start));
+            Perl_re_printf( aTHX_ "\n");
         }
 
       after_print:
@@ -20270,8 +20299,8 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
            for (word_idx= 0; word_idx < (I32)trie->wordcount; word_idx++) {
                SV ** const elem_ptr = av_fetch(trie_words,word_idx,0);
 
-                PerlIO_printf(Perl_debug_log, "%*s%s ",
-                   (int)(2*(indent+3)), "",
+                Perl_re_indentf( aTHX_  "%s ",
+                    indent+3,
                     elem_ptr
                     ? pv_pretty(sv, SvPV_nolen_const(*elem_ptr),
                                 SvCUR(*elem_ptr), 60,
@@ -20286,7 +20315,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
                 );
                 if (trie->jump) {
                     U16 dist= trie->jump[word_idx+1];
-                   PerlIO_printf(Perl_debug_log, "(%"UVuf")\n",
+                    Perl_re_printf( aTHX_  "(%"UVuf")\n",
                                (UV)((dist ? this_trie + dist : next) - start));
                     if (dist) {
                         if (!nextbranch)
@@ -20296,7 +20325,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
                     if (nextbranch && PL_regkind[OP(nextbranch)]==BRANCH)
                         nextbranch= regnext((regnode *)nextbranch);
                 } else {
-                    PerlIO_printf(Perl_debug_log, "\n");
+                    Perl_re_printf( aTHX_  "\n");
                }
            }
            if (last && next > last)
@@ -20336,7 +20365,7 @@ S_dumpuntil(pTHX_ const regexp *r, const regnode *start, const regnode *node,
     }
     CLEAR_OPTSTART;
 #ifdef DEBUG_DUMPUNTIL
-    PerlIO_printf(Perl_debug_log, "--- %d\n", (int)indent);
+    Perl_re_printf( aTHX_  "--- %d\n", (int)indent);
 #endif
     return node;
 }