nailed "our" declarations, and better warnings on duplicate
[p5sagit/p5-mst-13.2.git] / regcomp.c
index 65db009..90500a4 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -151,6 +151,7 @@ typedef struct scan_data_t {
     I32 offset_float_max;
     I32 flags;
     I32 whilem_c;
+    struct regnode_charclass_class *start_class;
 } scan_data_t;
 
 /*
@@ -158,7 +159,7 @@ typedef struct scan_data_t {
  */
 
 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-                                     0, 0, 0, 0 };
+                                     0, 0, 0, 0, 0 };
 
 #define SF_BEFORE_EOL          (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
 #define SF_BEFORE_SEOL         0x1
@@ -184,6 +185,9 @@ static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 #define SF_IN_PAR              0x100
 #define SF_HAS_EVAL            0x200
 #define SCF_DO_SUBSTR          0x400
+#define SCF_DO_STCLASS_AND     0x0800
+#define SCF_DO_STCLASS_OR      0x1000
+#define SCF_DO_STCLASS         (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
 
 #define RF_utf8                8
 #define UTF (PL_reg_flags & RF_utf8)
@@ -202,6 +206,10 @@ static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 
 static void clear_re(pTHXo_ void *r);
 
+/* Mark that we cannot extend a found fixed substring at this point.
+   Updata the longest found anchored substring and the longest found
+   floating substrings if needed. */
+
 STATIC void
 S_scan_commit(pTHX_ scan_data_t *data)
 {
@@ -236,6 +244,135 @@ S_scan_commit(pTHX_ scan_data_t *data)
     data->flags &= ~SF_BEFORE_EOL;
 }
 
+/* Can match anything (initialization) */
+STATIC void
+S_cl_anything(pTHX_ struct regnode_charclass_class *cl)
+{
+    int value;
+
+    ANYOF_CLASS_ZERO(cl);
+    for (value = 0; value < 256; ++value)
+       ANYOF_BITMAP_SET(cl, value);
+    cl->flags = ANYOF_EOS;
+    if (LOC)
+       cl->flags |= ANYOF_LOCALE;
+}
+
+/* Can match anything (initialization) */
+STATIC int
+S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
+{
+    int value;
+
+    for (value = 0; value < ANYOF_MAX; value += 2)
+       if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
+           return 1;
+    for (value = 0; value < 256; ++value)
+       if (!ANYOF_BITMAP_TEST(cl, value))
+           return 0;
+    return 1;
+}
+
+/* Can match anything (initialization) */
+STATIC void
+S_cl_init(pTHX_ struct regnode_charclass_class *cl)
+{
+    cl->type = ANYOF;
+    cl_anything(cl);
+}
+
+STATIC void
+S_cl_init_zero(pTHX_ struct regnode_charclass_class *cl)
+{
+    cl->type = ANYOF;
+    cl_anything(cl);
+    ANYOF_CLASS_ZERO(cl);
+    ANYOF_BITMAP_ZERO(cl);
+    if (LOC)
+       cl->flags |= ANYOF_LOCALE;
+}
+
+/* 'And' a given class with another one.  Can create false positives */
+/* We assume that cl is not inverted */
+STATIC void
+S_cl_and(pTHX_ struct regnode_charclass_class *cl,
+        struct regnode_charclass_class *and_with)
+{
+    int value;
+
+    if (!(and_with->flags & ANYOF_CLASS)
+       && !(cl->flags & ANYOF_CLASS)
+       && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
+       && !(and_with->flags & ANYOF_FOLD)
+       && !(cl->flags & ANYOF_FOLD)) {
+       int i;
+
+       if (and_with->flags & ANYOF_INVERT)
+           for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
+               cl->bitmap[i] &= ~and_with->bitmap[i];
+       else
+           for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
+               cl->bitmap[i] &= and_with->bitmap[i];
+    } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
+    if (!(and_with->flags & ANYOF_EOS))
+       cl->flags &= ~ANYOF_EOS;
+}
+
+/* 'OR' a given class with another one.  Can create false positives */
+/* We assume that cl is not inverted */
+STATIC void
+S_cl_or(pTHX_ struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
+{
+    int value;
+
+    if (or_with->flags & ANYOF_INVERT) {
+       /* We do not use
+        * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
+        *   <= (B1 | !B2) | (CL1 | !CL2)
+        * which is wasteful if CL2 is small, but we ignore CL2:
+        *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
+        * XXXX Can we handle case-fold?  Unclear:
+        *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
+        *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
+        */
+       if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
+            && !(or_with->flags & ANYOF_FOLD)
+            && !(cl->flags & ANYOF_FOLD) ) {
+           int i;
+
+           for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
+               cl->bitmap[i] |= ~or_with->bitmap[i];
+       } /* XXXX: logic is complicated otherwise */
+       else {
+           cl_anything(cl);
+       }
+    } else {
+       /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
+       if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
+            && (!(or_with->flags & ANYOF_FOLD) 
+                || (cl->flags & ANYOF_FOLD)) ) {
+           int i;
+
+           /* OR char bitmap and class bitmap separately */
+           for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
+               cl->bitmap[i] |= or_with->bitmap[i];
+           if (or_with->flags & ANYOF_CLASS) {
+               for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
+                   cl->classflags[i] |= or_with->classflags[i];
+               cl->flags |= ANYOF_CLASS;
+           }
+       }
+       else { /* XXXX: logic is complicated, leave it along for a moment. */
+           cl_anything(cl);
+       }
+    }
+    if (or_with->flags & ANYOF_EOS)
+       cl->flags |= ANYOF_EOS;
+}
+
+/* REx optimizer.  Converts nodes into quickier variants "in place".
+   Finds fixed substrings.  */
+
 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
    to the position after last scanned or to NULL. */
 
@@ -253,11 +390,13 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
     int is_inf_internal = 0;           /* The studied chunk is infinite */
     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
     scan_data_t data_fake;
+    struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
     
     while (scan && OP(scan) != END && scan < last) {
        /* Peephole optimizer: */
 
        if (PL_regkind[(U8)OP(scan)] == EXACT) {
+           /* Merge several consecutive EXACTish nodes into one. */
            regnode *n = regnext(scan);
            U32 stringok = 1;
 #ifdef DEBUGGING
@@ -305,19 +444,16 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
            /* Allow dumping */
            n = scan + NODE_SZ_STR(scan);
            while (n <= stop) {
-               /* Purify reports a benign UMR here sometimes, because we
-                * don't initialize the OP() slot of a node when that node
-                * is occupied by just the trailing null of the string in
-                * an EXACT node */
                if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
                    OP(n) = OPTIMIZED;
                    NEXT_OFF(n) = 0;
                }
                n++;
            }
-#endif 
-
+#endif
        }
+       /* Follow the next-chain of the current node and optimize
+          away all the NOTHINGs from it.  */
        if (OP(scan) != CURLYX) {
            int max = (reg_off_by_arg[OP(scan)]
                       ? I32_MAX
@@ -338,6 +474,8 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
            else 
                NEXT_OFF(scan) = off;
        }
+       /* The principal pseudo-switch.  Cannot be a switch, since we
+          look into several different things.  */
        if (OP(scan) == BRANCH || OP(scan) == BRANCHJ 
                   || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
            next = regnext(scan);
@@ -345,11 +483,15 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
            
            if (OP(next) == code || code == IFTHEN || code == SUSPEND) { 
                I32 max1 = 0, min1 = I32_MAX, num = 0;
+               struct regnode_charclass_class accum;
                
-               if (flags & SCF_DO_SUBSTR)
-                   scan_commit(data);
+               if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
+                   scan_commit(data);  /* Cannot merge strings after this. */
+               if (flags & SCF_DO_STCLASS)
+                   cl_init_zero(&accum);
                while (OP(scan) == code) {
-                   I32 deltanext, minnext;
+                   I32 deltanext, minnext, f = 0;
+                   struct regnode_charclass_class this_class;
 
                    num++;
                    data_fake.flags = 0;
@@ -359,9 +501,14 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                    scan = NEXTOPER(scan);
                    if (code != BRANCH)
                        scan = NEXTOPER(scan);
-                   /* We suppose the run is continuous, last=next...*/
+                   if (flags & SCF_DO_STCLASS) {
+                       cl_init(&this_class);
+                       data_fake.start_class = &this_class;
+                       f = SCF_DO_STCLASS_AND;
+                   }               
+                   /* we suppose the run is continuous, last=next...*/
                    minnext = study_chunk(&scan, &deltanext, next,
-                                         &data_fake, 0);
+                                         &data_fake, f);
                    if (min1 > minnext) 
                        min1 = minnext;
                    if (max1 < minnext + deltanext)
@@ -375,6 +522,8 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                        data->flags |= SF_HAS_EVAL;
                    if (data)
                        data->whilem_c = data_fake.whilem_c;
+                   if (flags & SCF_DO_STCLASS)
+                       cl_or(&accum, &this_class);
                    if (code == SUSPEND) 
                        break;
                }
@@ -388,6 +537,30 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                }
                min += min1;
                delta += max1 - min1;
+               if (flags & SCF_DO_STCLASS_OR) {
+                   cl_or(data->start_class, &accum);
+                   if (min1) {
+                       cl_and(data->start_class, &and_with);
+                       flags &= ~SCF_DO_STCLASS;
+                   }
+               }
+               else if (flags & SCF_DO_STCLASS_AND) {
+                   if (min1) {
+                       cl_and(data->start_class, &accum);
+                       flags &= ~SCF_DO_STCLASS;
+                   }
+                   else {
+                       /* Switch to OR mode: cache the old value of 
+                        * data->start_class */
+                       StructCopy(data->start_class, &and_with,
+                                  struct regnode_charclass_class);
+                       flags &= ~SCF_DO_STCLASS_AND;
+                       StructCopy(&accum, data->start_class,
+                                  struct regnode_charclass_class);
+                       flags |= SCF_DO_STCLASS_OR;
+                       data->start_class->flags |= ANYOF_EOS;
+                   }
+               }
            }
            else if (code == BRANCHJ)   /* single branch is optimized. */
                scan = NEXTOPER(NEXTOPER(scan));
@@ -421,9 +594,34 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                data->pos_min += l; /* As in the first entry. */
                data->flags &= ~SF_BEFORE_EOL;
            }
+           if (flags & SCF_DO_STCLASS_AND) {
+               /* Check whether it is compatible with what we know already! */
+               int compat = 1;
+
+               if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE)) 
+                   && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
+                   && (!(data->start_class->flags & ANYOF_FOLD)
+                       || !ANYOF_BITMAP_TEST(data->start_class,
+                                             PL_fold[*STRING(scan)])))
+                   compat = 0;
+               ANYOF_CLASS_ZERO(data->start_class);
+               ANYOF_BITMAP_ZERO(data->start_class);
+               if (compat)
+                   ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
+               data->start_class->flags &= ~ANYOF_EOS;
+           }
+           else if (flags & SCF_DO_STCLASS_OR) {
+               /* false positive possible if the class is case-folded */
+               ANYOF_BITMAP_SET(data->start_class, *STRING(scan));     
+               data->start_class->flags &= ~ANYOF_EOS;
+               cl_and(data->start_class, &and_with);
+           }
+           flags &= ~SCF_DO_STCLASS;
        }
-       else if (PL_regkind[(U8)OP(scan)] == EXACT) {
+       else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
            I32 l = STR_LEN(scan);
+
+           /* Search for fixed substrings supports EXACT only. */
            if (flags & SCF_DO_SUBSTR) 
                scan_commit(data);
            if (UTF) {
@@ -439,19 +637,51 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
            min += l;
            if (data && (flags & SCF_DO_SUBSTR))
                data->pos_min += l;
+           if (flags & SCF_DO_STCLASS_AND) {
+               /* Check whether it is compatible with what we know already! */
+               int compat = 1;
+
+               if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE)) 
+                   && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
+                   && !ANYOF_BITMAP_TEST(data->start_class, 
+                                         PL_fold[*STRING(scan)]))
+                   compat = 0;
+               ANYOF_CLASS_ZERO(data->start_class);
+               ANYOF_BITMAP_ZERO(data->start_class);
+               if (compat) {
+                   ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
+                   data->start_class->flags &= ~ANYOF_EOS;
+                   data->start_class->flags |= ANYOF_FOLD;
+                   if (OP(scan) == EXACTFL)
+                       data->start_class->flags |= ANYOF_LOCALE;
+               }
+           }
+           else if (flags & SCF_DO_STCLASS_OR) {
+               if (data->start_class->flags & ANYOF_FOLD) {
+                   /* false positive possible if the class is case-folded.
+                      Assume that the locale settings are the same... */
+                   ANYOF_BITMAP_SET(data->start_class, *STRING(scan)); 
+                   data->start_class->flags &= ~ANYOF_EOS;
+               }
+               cl_and(data->start_class, &and_with);
+           }
+           flags &= ~SCF_DO_STCLASS;
        }
        else if (strchr((char*)PL_varies,OP(scan))) {
            I32 mincount, maxcount, minnext, deltanext, pos_before, fl;
+           I32 f = flags;
            regnode *oscan = scan;
-           
+           struct regnode_charclass_class this_class;
+           struct regnode_charclass_class *oclass = NULL;
+
            switch (PL_regkind[(U8)OP(scan)]) {
-           case WHILEM:
+           case WHILEM:                /* End of (?:...)* . */
                scan = NEXTOPER(scan);
                goto finish;
            case PLUS:
-               if (flags & SCF_DO_SUBSTR) {
+               if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
                    next = NEXTOPER(scan);
-                   if (OP(next) == EXACT) {
+                   if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
                        mincount = 1; 
                        maxcount = REG_INFTY; 
                        next = regnext(scan);
@@ -464,10 +694,17 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                min++;
                /* Fall through. */
            case STAR:
+               if (flags & SCF_DO_STCLASS) {
+                   mincount = 0;
+                   maxcount = REG_INFTY; 
+                   next = regnext(scan);
+                   scan = NEXTOPER(scan);
+                   goto do_curly;
+               }
                is_inf = is_inf_internal = 1; 
                scan = regnext(scan);
                if (flags & SCF_DO_SUBSTR) {
-                   scan_commit(data);
+                   scan_commit(data);  /* Cannot extend fixed substrings */
                    data->longest = &(data->longest_float);
                }
                goto optimize_curly_tail;
@@ -478,7 +715,7 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
              do_curly:
                if (flags & SCF_DO_SUBSTR) {
-                   if (mincount == 0) scan_commit(data);
+                   if (mincount == 0) scan_commit(data); /* Cannot extend fixed substrings */
                    pos_before = data->pos_min;
                }
                if (data) {
@@ -487,10 +724,45 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                    if (is_inf)
                        data->flags |= SF_IS_INF;
                }
+               if (flags & SCF_DO_STCLASS) {
+                   cl_init(&this_class);
+                   oclass = data->start_class;
+                   data->start_class = &this_class;
+                   f |= SCF_DO_STCLASS_AND;
+                   f &= ~SCF_DO_STCLASS_OR;
+               }
+
                /* This will finish on WHILEM, setting scan, or on NULL: */
                minnext = study_chunk(&scan, &deltanext, last, data, 
                                      mincount == 0 
-                                       ? (flags & ~SCF_DO_SUBSTR) : flags);
+                                       ? (f & ~SCF_DO_SUBSTR) : f);
+
+               if (flags & SCF_DO_STCLASS)
+                   data->start_class = oclass;
+               if (mincount == 0 || minnext == 0) {
+                   if (flags & SCF_DO_STCLASS_OR) {
+                       cl_or(data->start_class, &this_class);
+                   }
+                   else if (flags & SCF_DO_STCLASS_AND) {
+                       /* Switch to OR mode: cache the old value of 
+                        * data->start_class */
+                       StructCopy(data->start_class, &and_with,
+                                  struct regnode_charclass_class);
+                       flags &= ~SCF_DO_STCLASS_AND;
+                       StructCopy(&this_class, data->start_class,
+                                  struct regnode_charclass_class);
+                       flags |= SCF_DO_STCLASS_OR;
+                       data->start_class->flags |= ANYOF_EOS;
+                   }
+               } else {                /* Non-zero len */
+                   if (flags & SCF_DO_STCLASS_OR) {
+                       cl_or(data->start_class, &this_class);
+                       cl_and(data->start_class, &and_with);
+                   }
+                   else if (flags & SCF_DO_STCLASS_AND)
+                       cl_and(data->start_class, &this_class);
+                   flags &= ~SCF_DO_STCLASS;
+               }
                if (!scan)              /* It was not CURLYX, but CURLY. */
                    scan = next;
                if (ckWARN(WARN_UNSAFE) && (minnext + deltanext == 0) 
@@ -640,6 +912,8 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                    data->pos_delta += - counted * deltanext +
                        (minnext + deltanext) * maxcount - minnext * mincount;
                    if (mincount != maxcount) {
+                        /* Cannot extend fixed substrings found inside
+                           the group.  */
                        scan_commit(data);
                        if (mincount && last_str) {
                            sv_setsv(data->last_found, last_str);
@@ -664,39 +938,258 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                        NEXT_OFF(oscan) += NEXT_OFF(next);
                }
                continue;
-           default:                    /* REF only? */
+           default:                    /* REF and CLUMP only? */
                if (flags & SCF_DO_SUBSTR) {
-                   scan_commit(data);
+                   scan_commit(data);  /* Cannot expect anything... */
                    data->longest = &(data->longest_float);
                }
                is_inf = is_inf_internal = 1;
+               if (flags & SCF_DO_STCLASS_OR)
+                   cl_anything(data->start_class);
+               flags &= ~SCF_DO_STCLASS;
                break;
            }
        }
        else if (strchr((char*)PL_simple,OP(scan)) || PL_regkind[(U8)OP(scan)] == ANYUTF8) {
+           int value;
+
            if (flags & SCF_DO_SUBSTR) {
                scan_commit(data);
                data->pos_min++;
            }
            min++;
+           if (flags & SCF_DO_STCLASS) {
+               data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
+
+               /* Some of the logic below assumes that switching
+                  locale on will only add false positives. */
+               switch (PL_regkind[(U8)OP(scan)]) {
+               case ANYUTF8:
+               case SANY:
+               case SANYUTF8:
+               case ALNUMUTF8:
+               case ANYOFUTF8:
+               case ALNUMLUTF8:
+               case NALNUMUTF8:
+               case NALNUMLUTF8:
+               case SPACEUTF8:
+               case NSPACEUTF8:
+               case SPACELUTF8:
+               case NSPACELUTF8:
+               case DIGITUTF8:
+               case NDIGITUTF8:
+               default:
+                 do_default:
+                   /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
+                   if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
+                       cl_anything(data->start_class);
+                   break;
+               case REG_ANY:
+                   if (OP(scan) == SANY)
+                       goto do_default;
+                   if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
+                       value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
+                                || (data->start_class->flags & ANYOF_CLASS));
+                       cl_anything(data->start_class);
+                   }
+                   if (flags & SCF_DO_STCLASS_AND || !value)
+                       ANYOF_BITMAP_CLEAR(data->start_class,'\n');
+                   break;
+               case ANYOF:
+                   if (flags & SCF_DO_STCLASS_AND)
+                       cl_and(data->start_class,
+                              (struct regnode_charclass_class*)scan);
+                   else
+                       cl_or(data->start_class,
+                             (struct regnode_charclass_class*)scan);
+                   break;
+               case ALNUM:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
+                           for (value = 0; value < 256; value++)
+                               if (!isALNUM(value))
+                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                       }
+                   }
+                   else {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
+                       else {
+                           for (value = 0; value < 256; value++)
+                               if (isALNUM(value))
+                                   ANYOF_BITMAP_SET(data->start_class, value);                     
+                       }
+                   }
+                   break;
+               case ALNUML:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
+                   }
+                   else {
+                       ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
+                       data->start_class->flags |= ANYOF_LOCALE;
+                   }
+                   break;
+               case NALNUM:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
+                           for (value = 0; value < 256; value++)
+                               if (isALNUM(value))
+                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                       }
+                   }
+                   else {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
+                       else {
+                           for (value = 0; value < 256; value++)
+                               if (!isALNUM(value))
+                                   ANYOF_BITMAP_SET(data->start_class, value);                     
+                       }
+                   }
+                   break;
+               case NALNUML:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
+                   }
+                   else {
+                       data->start_class->flags |= ANYOF_LOCALE;
+                       ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
+                   }
+                   break;
+               case SPACE:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
+                           for (value = 0; value < 256; value++)
+                               if (!isSPACE(value))
+                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                       }
+                   }
+                   else {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
+                       else {
+                           for (value = 0; value < 256; value++)
+                               if (isSPACE(value))
+                                   ANYOF_BITMAP_SET(data->start_class, value);                     
+                       }
+                   }
+                   break;
+               case SPACEL:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
+                   }
+                   else {
+                       data->start_class->flags |= ANYOF_LOCALE;
+                       ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
+                   }
+                   break;
+               case NSPACE:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (!(data->start_class->flags & ANYOF_LOCALE)) {
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
+                           for (value = 0; value < 256; value++)
+                               if (isSPACE(value))
+                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                       }
+                   }
+                   else {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
+                       else {
+                           for (value = 0; value < 256; value++)
+                               if (!isSPACE(value))
+                                   ANYOF_BITMAP_SET(data->start_class, value);                     
+                       }
+                   }
+                   break;
+               case NSPACEL:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       if (data->start_class->flags & ANYOF_LOCALE) {
+                           ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
+                           for (value = 0; value < 256; value++)
+                               if (!isSPACE(value))
+                                   ANYOF_BITMAP_CLEAR(data->start_class, value);
+                       }
+                   }
+                   else {
+                       data->start_class->flags |= ANYOF_LOCALE;
+                       ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
+                   }
+                   break;
+               case DIGIT:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
+                       for (value = 0; value < 256; value++)
+                           if (!isDIGIT(value))
+                               ANYOF_BITMAP_CLEAR(data->start_class, value);
+                   }
+                   else {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
+                       else {
+                           for (value = 0; value < 256; value++)
+                               if (isDIGIT(value))
+                                   ANYOF_BITMAP_SET(data->start_class, value);                     
+                       }
+                   }
+                   break;
+               case NDIGIT:
+                   if (flags & SCF_DO_STCLASS_AND) {
+                       ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
+                       for (value = 0; value < 256; value++)
+                           if (isDIGIT(value))
+                               ANYOF_BITMAP_CLEAR(data->start_class, value);
+                   }
+                   else {
+                       if (data->start_class->flags & ANYOF_LOCALE)
+                           ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
+                       else {
+                           for (value = 0; value < 256; value++)
+                               if (!isDIGIT(value))
+                                   ANYOF_BITMAP_SET(data->start_class, value);                     
+                       }
+                   }
+                   break;
+               }
+               if (flags & SCF_DO_STCLASS_OR)
+                   cl_and(data->start_class, &and_with);
+               flags &= ~SCF_DO_STCLASS;
+           }
        }
        else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
            data->flags |= (OP(scan) == MEOL
                            ? SF_BEFORE_MEOL
                            : SF_BEFORE_SEOL);
        }
-       else if (PL_regkind[(U8)OP(scan)] == BRANCHJ
-                  && (scan->flags || data)
+       else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
+                /* Lookbehind, or need to calculate parens/evals/stclass: */
+                  && (scan->flags || data || (flags & SCF_DO_STCLASS))
                   && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
+           /* Lookahead/lookbehind */
            I32 deltanext, minnext;
            regnode *nscan;
+           struct regnode_charclass_class intrnl;
+           int f = 0;
 
            data_fake.flags = 0;
            if (data)
                data_fake.whilem_c = data->whilem_c;
+           if ( flags & SCF_DO_STCLASS && !scan->flags
+                && OP(scan) == IFMATCH ) { /* Lookahead */
+               cl_init(&intrnl);
+               data_fake.start_class = &intrnl;
+               f = SCF_DO_STCLASS_AND;
+           }
            next = regnext(scan);
            nscan = NEXTOPER(NEXTOPER(scan));
-           minnext = study_chunk(&nscan, &deltanext, last, &data_fake, 0);
+           minnext = study_chunk(&nscan, &deltanext, last, &data_fake, f);
            if (scan->flags) {
                if (deltanext) {
                    FAIL("variable length lookbehind not implemented");
@@ -712,6 +1205,13 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                data->flags |= SF_HAS_EVAL;
            if (data)
                data->whilem_c = data_fake.whilem_c;
+           if (f) {
+               int was = (data->start_class->flags & ANYOF_EOS);
+
+               cl_and(data->start_class, &intrnl);
+               if (was)
+                   data->start_class->flags |= ANYOF_EOS;
+           }
        }
        else if (OP(scan) == OPEN) {
            pars++;
@@ -732,6 +1232,8 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
                    data->longest = &(data->longest_float);
                }
                is_inf = is_inf_internal = 1;
+               if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
+                   cl_anything(data->start_class);
        }
        /* Else: zero-length, ignore. */
        scan = regnext(scan);
@@ -752,6 +1254,8 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
        data->flags |= SF_HAS_PAR;
        data->flags &= ~SF_IN_PAR;
     }
+    if (flags & SCF_DO_STCLASS_OR)
+       cl_and(data->start_class, &and_with);
     return min;
 }
 
@@ -924,16 +1428,21 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     Newz(1004, r->substrs, 1, struct reg_substr_data);
 
     StructCopy(&zero_scan_data, &data, scan_data_t);
+    /* XXXX Should not we check for something else?  Usually it is OPEN1... */
     if (OP(scan) != BRANCH) {  /* Only one top-level choice. */
        I32 fake;
        STRLEN longest_float_length, longest_fixed_length;
+       struct regnode_charclass_class ch_class;
+       int stclass_flag;
 
        first = scan;
        /* Skip introductions and multiplicators >= 1. */
        while ((OP(first) == OPEN && (sawopen = 1)) ||
+              /* An OR of *one* alternative - should not happen now. */
            (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
            (OP(first) == PLUS) ||
            (OP(first) == MINMOD) ||
+              /* An {n,m} with n>0 */
            (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
                if (OP(first) == PLUS)
                    sawplus = 1;
@@ -944,13 +1453,13 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
 
        /* Starting-point info. */
       again:
-       if (PL_regkind[(U8)OP(first) == EXACT]) {
+       if (PL_regkind[(U8)OP(first)] == EXACT) {
            if (OP(first) == EXACT);    /* Empty, get anchored substr later. */
            else if ((OP(first) == EXACTF || OP(first) == EXACTFL)
                     && !UTF)
                r->regstclass = first;
        }
-       else if (strchr((char*)PL_simple+4,OP(first)))
+       else if (strchr((char*)PL_simple,OP(first)))
            r->regstclass = first;
        else if (PL_regkind[(U8)OP(first)] == BOUND ||
                 PL_regkind[(U8)OP(first)] == NBOUND)
@@ -1011,9 +1520,15 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
        data.last_found = newSVpvn("",0);
        data.longest = &(data.longest_fixed);
        first = scan;
-       
+       if (!r->regstclass) {
+           cl_init(&ch_class);
+           data.start_class = &ch_class;
+           stclass_flag = SCF_DO_STCLASS_AND;
+       } else                          /* XXXX Check for BOUND? */
+           stclass_flag = 0;
+
        minlen = study_chunk(&first, &fake, scan + PL_regsize, /* Up to end */
-                            &data, SCF_DO_SUBSTR);
+                            &data, SCF_DO_SUBSTR | stclass_flag);
        if ( PL_regnpar == 1 && data.longest == &(data.longest_fixed)
             && data.last_start_min == 0 && data.last_end > 0 
             && !PL_seen_zerolen
@@ -1068,6 +1583,28 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
            SvREFCNT_dec(data.longest_fixed);
            longest_fixed_length = 0;
        }
+       if (r->regstclass 
+           && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == ANYUTF8
+               || OP(r->regstclass) == SANYUTF8 || OP(r->regstclass) == SANY))
+           r->regstclass = NULL;
+       if ((!r->anchored_substr || r->anchored_offset) && stclass_flag
+           && !(data.start_class->flags & ANYOF_EOS)
+           && !cl_is_anything(data.start_class)) {
+           SV *sv;
+           I32 n = add_data(1, "f");
+
+           New(1006, PL_regcomp_rx->data->data[n], 1, 
+               struct regnode_charclass_class);
+           StructCopy(data.start_class,
+                      (struct regnode_charclass_class*)PL_regcomp_rx->data->data[n],
+                      struct regnode_charclass_class);
+           r->regstclass = (regnode*)PL_regcomp_rx->data->data[n];
+           r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
+           DEBUG_r((sv = sv_newmortal(),
+                    regprop(sv, (regnode*)data.start_class),
+                    PerlIO_printf(Perl_debug_log, "synthetic stclass.\n",
+                                  SvPVX(sv))));
+       }
 
        /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
        if (longest_fixed_length > longest_float_length) {
@@ -1092,11 +1629,31 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     else {
        /* Several toplevels. Best we can is to set minlen. */
        I32 fake;
+       struct regnode_charclass_class ch_class;
        
        DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
        scan = r->program + 1;
-       minlen = study_chunk(&scan, &fake, scan + PL_regsize, &data, 0);
+       cl_init(&ch_class);
+       data.start_class = &ch_class;
+       minlen = study_chunk(&scan, &fake, scan + PL_regsize, &data, SCF_DO_STCLASS_AND);
        r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
+       if (!(data.start_class->flags & ANYOF_EOS)
+           && !cl_is_anything(data.start_class)) {
+           SV *sv;
+           I32 n = add_data(1, "f");
+
+           New(1006, PL_regcomp_rx->data->data[n], 1, 
+               struct regnode_charclass_class);
+           StructCopy(data.start_class,
+                      (struct regnode_charclass_class*)PL_regcomp_rx->data->data[n],
+                      struct regnode_charclass_class);
+           r->regstclass = (regnode*)PL_regcomp_rx->data->data[n];
+           r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
+           DEBUG_r((sv = sv_newmortal(),
+                    regprop(sv, (regnode*)data.start_class),
+                    PerlIO_printf(Perl_debug_log, "synthetic stclass.\n",
+                                  SvPVX(sv))));
+       }
     }
 
     r->minlen = minlen;
@@ -2013,11 +2570,19 @@ tryagain:
                        p++;
                        break;
                    case 'e':
-                       ender = '\033';
+#ifdef ASCIIish
+                         ender = '\033';
+#else
+                         ender = '\047';
+#endif
                        p++;
                        break;
                    case 'a':
-                       ender = '\007';
+#ifdef ASCIIish
+                         ender = '\007';
+#else
+                         ender = '\057';
+#endif
                        p++;
                        break;
                    case 'x':
@@ -2353,8 +2918,13 @@ S_regclass(pTHX)
            case 't':   value = '\t';                   break;
            case 'f':   value = '\f';                   break;
            case 'b':   value = '\b';                   break;
+#ifdef ASCIIish
            case 'e':   value = '\033';                 break;
            case 'a':   value = '\007';                 break;
+#else
+           case 'e':   value = '\047';                 break;
+           case 'a':   value = '\057';                 break;
+#endif
            case 'x':
                value = (UV)scan_hex(PL_regcomp_parse, 2, &numlen);
                PL_regcomp_parse += numlen;
@@ -2373,7 +2943,7 @@ S_regclass(pTHX)
                    Perl_warner(aTHX_ WARN_UNSAFE, 
                                "/%.127s/: Unrecognized escape \\%c in character class passed through",
                                PL_regprecomp,
-                               value);
+                               (int)value);
                break;
            }
        }
@@ -2491,16 +3061,28 @@ S_regclass(pTHX)
                    if (LOC)
                        ANYOF_CLASS_SET(ret, ANYOF_ASCII);
                    else {
+#ifdef ASCIIish
                        for (value = 0; value < 128; value++)
                            ANYOF_BITMAP_SET(ret, value);
+#else  /* EBCDIC */
+                       for (value = 0; value < 256; value++)
+                           if (isASCII(value))
+                               ANYOF_BITMAP_SET(ret, value);
+#endif /* EBCDIC */
                    }
                    break;
                case ANYOF_NASCII:
                    if (LOC)
                        ANYOF_CLASS_SET(ret, ANYOF_NASCII);
                    else {
+#ifdef ASCIIish
                        for (value = 128; value < 256; value++)
                            ANYOF_BITMAP_SET(ret, value);
+#else  /* EBCDIC */
+                       for (value = 0; value < 256; value++)
+                           if (!isASCII(value))
+                               ANYOF_BITMAP_SET(ret, value);
+#endif /* EBCDIC */
                    }
                    break;
                case ANYOF_CNTRL:
@@ -2803,8 +3385,13 @@ S_regclassutf8(pTHX)
            case 't':           value = '\t';           break;
            case 'f':           value = '\f';           break;
            case 'b':           value = '\b';           break;
+#ifdef ASCIIish
            case 'e':           value = '\033';         break;
            case 'a':           value = '\007';         break;
+#else
+           case 'e':           value = '\047';         break;
+           case 'a':           value = '\057';         break;
+#endif
            case 'x':
                if (*PL_regcomp_parse == '{') {
                    e = strchr(PL_regcomp_parse++, '}');
@@ -2834,7 +3421,7 @@ S_regclassutf8(pTHX)
                    Perl_warner(aTHX_ WARN_UNSAFE, 
                                "/%.127s/: Unrecognized escape \\%c in character class passed through",
                                PL_regprecomp,
-                               value);
+                               (int)value);
                break;
            }
        }
@@ -3310,6 +3897,17 @@ Perl_regdump(pTHX_ regexp *r)
 #endif /* DEBUGGING */
 }
 
+STATIC void
+S_put_byte(pTHX_ SV *sv, int c)
+{
+    if (c <= ' ' || c == 127 || c == 255)
+       Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
+    else if (c == '-' || c == ']' || c == '\\' || c == '^')
+       Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
+    else
+       Perl_sv_catpvf(aTHX_ sv, "%c", c);
+}
+
 /*
 - regprop - printable representation of opcode
 */
@@ -3341,6 +3939,67 @@ Perl_regprop(pTHX_ SV *sv, regnode *o)
        Perl_sv_catpvf(aTHX_ sv, "%d", ARG(o)); /* Parenth number */
     else if (k == LOGICAL)
        Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
+    else if (k == ANYOF) {
+       int i, rangestart = -1;
+       const char * const out[] = {    /* Should be syncronized with
+                                          a table in regcomp.h */
+           "\\w",
+           "\\W",
+           "\\s",
+           "\\S",
+           "\\d",
+           "\\D",
+           "[:alnum:]",
+           "[:^alnum:]",
+           "[:alpha:]",
+           "[:^alpha:]",
+           "[:ascii:]",
+           "[:^ascii:]",
+           "[:ctrl:]",
+           "[:^ctrl:]",
+           "[:graph:]",
+           "[:^graph:]",
+           "[:lower:]",
+           "[:^lower:]",
+           "[:print:]",
+           "[:^print:]",
+           "[:punct:]",
+           "[:^punct:]",
+           "[:upper:]",
+           "[:!upper:]",
+           "[:xdigit:]",
+           "[:^xdigit:]"
+       };
+
+       if (o->flags & ANYOF_LOCALE)
+           sv_catpv(sv, "{loc}");
+       if (o->flags & ANYOF_FOLD)
+           sv_catpv(sv, "{i}");
+       Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
+       if (o->flags & ANYOF_INVERT)
+           sv_catpv(sv, "^");
+       for (i = 0; i <= 256; i++) {
+           if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
+               if (rangestart == -1)
+                   rangestart = i;
+           } else if (rangestart != -1) {
+               if (i <= rangestart + 3)
+                   for (; rangestart < i; rangestart++)
+                       put_byte(sv, rangestart);
+               else {
+                   put_byte(sv, rangestart);
+                   sv_catpv(sv, "-");
+                   put_byte(sv, i - 1);
+               }
+               rangestart = -1;
+           }
+       }
+       if (o->flags & ANYOF_CLASS)
+           for (i = 0; i < sizeof(out)/sizeof(char*); i++)
+               if (ANYOF_CLASS_TEST(o,i))
+                   sv_catpv(sv, out[i]);
+       Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
+    }
     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
        Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
 #endif /* DEBUGGING */
@@ -3402,6 +4061,9 @@ Perl_pregfree(pTHX_ struct regexp *r)
            case 's':
                SvREFCNT_dec((SV*)r->data->data[n]);
                break;
+           case 'f':
+               Safefree(r->data->data[n]);
+               break;
            case 'p':
                new_comppad = (AV*)r->data->data[n];
                break;
@@ -3506,7 +4168,7 @@ Perl_save_re_context(pTHX)
     SAVEVPTR(PL_regendp);              /* Ditto for endp. */
     SAVEVPTR(PL_reglastparen);         /* Similarly for lastparen. */
     SAVEPPTR(PL_regtill);              /* How far we are required to go. */
-    SAVEI32(PL_regprev);               /* char before regbol, \n if none */
+    SAVEI8(PL_regprev);                        /* char before regbol, \n if none */
     SAVEVPTR(PL_reg_start_tmp);                /* from regexec.c */
     PL_reg_start_tmp = 0;
     SAVEFREEPV(PL_reg_start_tmp);