Updated version 6.4.0 from 'upstream/6.4.0'

with Debian dir c94f3039d51e97ec5152e0857aee3095c04a8323

12 files changed, 2998 insertions, 2357 deletions

diff --git a/src/config.h.cmake.in b/src/config.h.cmake.in
index 93e46c0..e13fad1 100644
--- a/src/config.h.cmake.in
+++ b/src/config.h.cmake.in
@@ -43,6 +43,9 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #cmakedefine HAVE_UNISTD_H  ${HAVE_UNISTD_H}
 
+/* Define to 1 if you have the <inttypes.h> header file. */
+#cmakedefine HAVE_INTTYPES_H  ${HAVE_INTTYPES_H}
+
 /* Name of package */
 #cmakedefine PACKAGE  ${PACKAGE}
 
diff --git a/src/oniguruma.h b/src/oniguruma.h
index 02d4254..a8ae09a 100644
--- a/src/oniguruma.h
+++ b/src/oniguruma.h
@@ -35,7 +35,7 @@ extern "C" {
 
 #define ONIGURUMA
 #define ONIGURUMA_VERSION_MAJOR   6
-#define ONIGURUMA_VERSION_MINOR   3
+#define ONIGURUMA_VERSION_MINOR   4
 #define ONIGURUMA_VERSION_TEENY   0
 
 #ifdef __cplusplus
@@ -609,7 +609,7 @@ ONIG_EXTERN OnigSyntaxType*   OnigDefaultSyntax;
 /* #define ONIGERR_OVER_THREAD_PASS_LIMIT_COUNT                -1001 */
 
 
-/* must be smaller than BIT_STATUS_BITS_NUM (unsigned int * 8) */
+/* must be smaller than MEM_STATUS_BITS_NUM (unsigned int * 8) */
 #define ONIG_MAX_CAPTURE_HISTORY_GROUP   31
 #define ONIG_IS_CAPTURE_HISTORY_GROUP(r, i) \
   ((i) <= ONIG_MAX_CAPTURE_HISTORY_GROUP && (r)->list && (r)->list[i])
@@ -669,7 +669,7 @@ typedef struct re_pattern_buffer {
 
   int num_mem;                   /* used memory(...) num counted from 1 */
   int num_repeat;                /* OP_REPEAT/OP_REPEAT_NG id-counter */
-  int num_null_check;            /* OP_NULL_CHECK_START/END id counter */
+  int num_null_check;            /* OP_EMPTY_CHECK_START/END id counter */
   int num_comb_exp_check;        /* combination explosion check */
   int num_call;                  /* number of subexp call */
   unsigned int capture_history;  /* (?@...) flag (1-31) */
diff --git a/src/regcomp.c b/src/regcomp.c
index 0e9a9ab..db83739 100644
--- a/src/regcomp.c
+++ b/src/regcomp.c
@@ -29,6 +29,83 @@
 
 #include "regparse.h"
 
+#if 0
+typedef struct {
+  int  n;
+  int  alloc;
+  int* v;
+} int_stack;
+
+static int
+make_int_stack(int_stack** rs, int init_size)
+{
+  int_stack* s;
+  int* v;
+
+  *rs = 0;
+
+  s = xmalloc(sizeof(*s));
+  if (IS_NULL(s)) return ONIGERR_MEMORY;
+
+  v = (int* )xmalloc(sizeof(int) * init_size);
+  if (IS_NULL(v)) {
+    xfree(s);
+    return ONIGERR_MEMORY;
+  }
+
+  s->n = 0;
+  s->alloc = init_size;
+  s->v = v;
+
+  *rs = s;
+  return ONIG_NORMAL;
+}
+
+static void
+free_int_stack(int_stack* s)
+{
+  if (IS_NOT_NULL(s)) {
+    if (IS_NOT_NULL(s->v))
+      xfree(s->v);
+    xfree(s);
+  }
+}
+
+static int
+int_stack_push(int_stack* s, int v)
+{
+  if (s->n >= s->alloc) {
+    int new_size = s->alloc * 2;
+    int* nv = (int* )xrealloc(s->v, new_size);
+    if (IS_NULL(nv)) return ONIGERR_MEMORY;
+
+    s->alloc = new_size;
+    s->v = nv;
+  }
+
+  s->v[s->n] = v;
+  s->n++;
+  return ONIG_NORMAL;
+}
+
+static int
+int_stack_pop(int_stack* s)
+{
+  int v;
+
+#ifdef ONIG_DEBUG
+  if (s->n <= 0) {
+    fprintf(stderr, "int_stack_pop: fail empty. %p\n", s);
+    return 0;
+  }
+#endif
+
+  v = s->v[s->n];
+  s->n--;
+  return v;
+}
+#endif
+
 OnigCaseFoldType OnigDefaultCaseFoldFlag = ONIGENC_CASE_FOLD_MIN;
 
 extern OnigCaseFoldType
@@ -70,8 +147,8 @@ swap_node(Node* a, Node* b)
   Node c;
   c = *a; *a = *b; *b = c;
 
-  if (NTYPE(a) == NT_STR) {
-    StrNode* sn = NSTR(a);
+  if (NODE_TYPE(a) == NODE_STR) {
+    StrNode* sn = STR_(a);
     if (sn->capa == 0) {
       int len = sn->end - sn->s;
       sn->s   = sn->buf;
@@ -79,8 +156,8 @@ swap_node(Node* a, Node* b)
     }
   }
 
-  if (NTYPE(b) == NT_STR) {
-    StrNode* sn = NSTR(b);
+  if (NODE_TYPE(b) == NODE_STR) {
+    StrNode* sn = STR_(b);
     if (sn->capa == 0) {
       int len = sn->end - sn->s;
       sn->s   = sn->buf;
@@ -156,42 +233,42 @@ onig_bbuf_init(BBuf* buf, int size)
 #ifdef USE_SUBEXP_CALL
 
 static int
-unset_addr_list_init(UnsetAddrList* uslist, int size)
+unset_addr_list_init(UnsetAddrList* list, int size)
 {
   UnsetAddr* p;
 
   p = (UnsetAddr* )xmalloc(sizeof(UnsetAddr)* size);
   CHECK_NULL_RETURN_MEMERR(p);
-  uslist->num   = 0;
-  uslist->alloc = size;
-  uslist->us    = p;
+  list->num   = 0;
+  list->alloc = size;
+  list->us    = p;
   return 0;
 }
 
 static void
-unset_addr_list_end(UnsetAddrList* uslist)
+unset_addr_list_end(UnsetAddrList* list)
 {
-  if (IS_NOT_NULL(uslist->us))
-    xfree(uslist->us);
+  if (IS_NOT_NULL(list->us))
+    xfree(list->us);
 }
 
 static int
-unset_addr_list_add(UnsetAddrList* uslist, int offset, struct _Node* node)
+unset_addr_list_add(UnsetAddrList* list, int offset, struct _Node* node)
 {
   UnsetAddr* p;
   int size;
 
-  if (uslist->num >= uslist->alloc) {
-    size = uslist->alloc * 2;
-    p = (UnsetAddr* )xrealloc(uslist->us, sizeof(UnsetAddr) * size);
+  if (list->num >= list->alloc) {
+    size = list->alloc * 2;
+    p = (UnsetAddr* )xrealloc(list->us, sizeof(UnsetAddr) * size);
     CHECK_NULL_RETURN_MEMERR(p);
-    uslist->alloc = size;
-    uslist->us    = p;
+    list->alloc = size;
+    list->us    = p;
   }
 
-  uslist->us[uslist->num].offset = offset;
-  uslist->us[uslist->num].target = node;
-  uslist->num++;
+  list->us[list->num].offset = offset;
+  list->us[list->num].target = node;
+  list->num++;
   return 0;
 }
 #endif /* USE_SUBEXP_CALL */
@@ -251,6 +328,7 @@ add_mem_num(regex_t* reg, int num)
   return 0;
 }
 
+#if 0
 static int
 add_pointer(regex_t* reg, void* addr)
 {
@@ -259,6 +337,7 @@ add_pointer(regex_t* reg, void* addr)
   BBUF_ADD(reg, &ptr, SIZE_POINTER);
   return 0;
 }
+#endif
 
 static int
 add_option(regex_t* reg, OnigOptionType option)
@@ -273,7 +352,7 @@ add_opcode_rel_addr(regex_t* reg, int opcode, int addr)
   int r;
 
   r = add_opcode(reg, opcode);
-  if (r) return r;
+  if (r != 0) return r;
   r = add_rel_addr(reg, addr);
   return r;
 }
@@ -298,13 +377,13 @@ add_opcode_option(regex_t* reg, int opcode, OnigOptionType option)
   int r;
 
   r = add_opcode(reg, opcode);
-  if (r) return r;
+  if (r != 0) return r;
   r = add_option(reg, option);
   return r;
 }
 
 static int compile_length_tree(Node* node, regex_t* reg);
-static int compile_tree(Node* node, regex_t* reg);
+static int compile_tree(Node* node, regex_t* reg, ScanEnv* env);
 
 
 #define IS_NEED_STR_LEN_OP_EXACT(op) \
@@ -357,31 +436,31 @@ select_str_opcode(int mb_len, int str_len, int ignore_case)
 }
 
 static int
-compile_tree_empty_check(Node* node, regex_t* reg, int empty_info)
+compile_tree_empty_check(Node* node, regex_t* reg, int empty_info, ScanEnv* env)
 {
   int r;
   int saved_num_null_check = reg->num_null_check;
 
-  if (empty_info != 0) {
-    r = add_opcode(reg, OP_NULL_CHECK_START);
-    if (r) return r;
+  if (empty_info != QUANT_BODY_IS_NOT_EMPTY) {
+    r = add_opcode(reg, OP_EMPTY_CHECK_START);
+    if (r != 0) return r;
     r = add_mem_num(reg, reg->num_null_check); /* NULL CHECK ID */
-    if (r) return r;
+    if (r != 0) return r;
     reg->num_null_check++;
   }
 
-  r = compile_tree(node, reg);
-  if (r) return r;
+  r = compile_tree(node, reg, env);
+  if (r != 0) return r;
 
-  if (empty_info != 0) {
-    if (empty_info == NQ_TARGET_IS_EMPTY)
-      r = add_opcode(reg, OP_NULL_CHECK_END);
-    else if (empty_info == NQ_TARGET_IS_EMPTY_MEM)
-      r = add_opcode(reg, OP_NULL_CHECK_END_MEMST);
-    else if (empty_info == NQ_TARGET_IS_EMPTY_REC)
-      r = add_opcode(reg, OP_NULL_CHECK_END_MEMST_PUSH);
+  if (empty_info != QUANT_BODY_IS_NOT_EMPTY) {
+    if (empty_info == QUANT_BODY_IS_EMPTY)
+      r = add_opcode(reg, OP_EMPTY_CHECK_END);
+    else if (empty_info == QUANT_BODY_IS_EMPTY_MEM)
+      r = add_opcode(reg, OP_EMPTY_CHECK_END_MEMST);
+    else if (empty_info == QUANT_BODY_IS_EMPTY_REC)
+      r = add_opcode(reg, OP_EMPTY_CHECK_END_MEMST_PUSH);
 
-    if (r) return r;
+    if (r != 0) return r;
     r = add_mem_num(reg, saved_num_null_check); /* NULL CHECK ID */
   }
   return r;
@@ -389,28 +468,28 @@ compile_tree_empty_check(Node* node, regex_t* reg, int empty_info)
 
 #ifdef USE_SUBEXP_CALL
 static int
-compile_call(CallNode* node, regex_t* reg)
+compile_call(CallNode* node, regex_t* reg, ScanEnv* env)
 {
   int r;
 
   r = add_opcode(reg, OP_CALL);
-  if (r) return r;
-  r = unset_addr_list_add(node->unset_addr_list, BBUF_GET_OFFSET_POS(reg),
-                          node->target);
-  if (r) return r;
+  if (r != 0) return r;
+  r = unset_addr_list_add(env->unset_addr_list, BBUF_GET_OFFSET_POS(reg),
+                          NODE_CALL_BODY(node));
+  if (r != 0) return r;
   r = add_abs_addr(reg, 0 /*dummy addr.*/);
   return r;
 }
 #endif
 
 static int
-compile_tree_n_times(Node* node, int n, regex_t* reg)
+compile_tree_n_times(Node* node, int n, regex_t* reg, ScanEnv* env)
 {
   int i, r;
 
   for (i = 0; i < n; i++) {
-    r = compile_tree(node, reg);
-    if (r) return r;
+    r = compile_tree(node, reg, env);
+    if (r != 0) return r;
   }
   return 0;
 }
@@ -462,7 +541,7 @@ compile_length_string_node(Node* node, regex_t* reg)
   UChar *p, *prev;
   StrNode* sn;
 
-  sn = NSTR(node);
+  sn = STR_(node);
   if (sn->end <= sn->s)
     return 0;
 
@@ -510,7 +589,7 @@ compile_string_node(Node* node, regex_t* reg)
   UChar *p, *prev, *end;
   StrNode* sn;
 
-  sn = NSTR(node);
+  sn = STR_(node);
   if (sn->end <= sn->s)
     return 0;
 
@@ -529,7 +608,7 @@ compile_string_node(Node* node, regex_t* reg)
     }
     else {
       r = add_compile_string(prev, prev_len, slen, reg, ambig);
-      if (r) return r;
+      if (r != 0) return r;
 
       prev  = p;
       slen  = 1;
@@ -578,11 +657,6 @@ compile_length_cclass_node(CClassNode* cc, regex_t* reg)
 {
   int len;
 
-  if (IS_NCCLASS_SHARE(cc)) {
-    len = SIZE_OPCODE + SIZE_POINTER;
-    return len;
-  }
-
   if (IS_NULL(cc->mbuf)) {
     len = SIZE_OPCODE + SIZE_BITSET;
   }
@@ -608,12 +682,6 @@ compile_cclass_node(CClassNode* cc, regex_t* reg)
 {
   int r;
 
-  if (IS_NCCLASS_SHARE(cc)) {
-    add_opcode(reg, OP_CCLASS_NODE);
-    r = add_pointer(reg, cc);
-    return r;
-  }
-
   if (IS_NULL(cc->mbuf)) {
     if (IS_NCCLASS_NOT(cc))
       add_opcode(reg, OP_CCLASS_NOT);
@@ -638,7 +706,7 @@ compile_cclass_node(CClassNode* cc, regex_t* reg)
         add_opcode(reg, OP_CCLASS_MIX);
 
       r = add_bitset(reg, cc->bs);
-      if (r) return r;
+      if (r != 0) return r;
       r = add_multi_byte_cclass(cc->mbuf, reg);
     }
   }
@@ -678,46 +746,46 @@ entry_repeat_range(regex_t* reg, int id, int lower, int upper)
 }
 
 static int
-compile_range_repeat_node(QtfrNode* qn, int target_len, int empty_info,
-                          regex_t* reg)
+compile_range_repeat_node(QuantNode* qn, int target_len, int empty_info,
+                          regex_t* reg, ScanEnv* env)
 {
   int r;
   int num_repeat = reg->num_repeat;
 
   r = add_opcode(reg, qn->greedy ? OP_REPEAT : OP_REPEAT_NG);
-  if (r) return r;
+  if (r != 0) return r;
   r = add_mem_num(reg, num_repeat); /* OP_REPEAT ID */
   reg->num_repeat++;
-  if (r) return r;
+  if (r != 0) return r;
   r = add_rel_addr(reg, target_len + SIZE_OP_REPEAT_INC);
-  if (r) return r;
+  if (r != 0) return r;
 
   r = entry_repeat_range(reg, num_repeat, qn->lower, qn->upper);
-  if (r) return r;
+  if (r != 0) return r;
 
-  r = compile_tree_empty_check(qn->target, reg, empty_info);
-  if (r) return r;
+  r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+  if (r != 0) return r;
 
   if (
 #ifdef USE_SUBEXP_CALL
-      reg->num_call > 0 ||
+      NODE_IS_IN_MULTI_ENTRY(qn) ||
 #endif
-      IS_QUANTIFIER_IN_REPEAT(qn)) {
+      NODE_IS_IN_REAL_REPEAT(qn)) {
     r = add_opcode(reg, qn->greedy ? OP_REPEAT_INC_SG : OP_REPEAT_INC_NG_SG);
   }
   else {
     r = add_opcode(reg, qn->greedy ? OP_REPEAT_INC : OP_REPEAT_INC_NG);
   }
-  if (r) return r;
+  if (r != 0) return r;
   r = add_mem_num(reg, num_repeat); /* OP_REPEAT ID */
   return r;
 }
 
 static int
-is_anychar_star_quantifier(QtfrNode* qn)
+is_anychar_star_quantifier(QuantNode* qn)
 {
   if (qn->greedy && IS_REPEAT_INFINITE(qn->upper) &&
-      NTYPE(qn->target) == NT_CANY)
+      NODE_IS_ANYCHAR(NODE_QUANT_BODY(qn)))
     return 1;
   else
     return 0;
@@ -729,13 +797,13 @@ is_anychar_star_quantifier(QtfrNode* qn)
 #ifdef USE_COMBINATION_EXPLOSION_CHECK
 
 static int
-compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
+compile_length_quantifier_node(QuantNode* qn, regex_t* reg)
 {
   int len, mod_tlen, cklen;
   int ckn;
   int infinite = IS_REPEAT_INFINITE(qn->upper);
-  int empty_info = qn->target_empty_info;
-  int tlen = compile_length_tree(qn->target, reg);
+  int empty_info = qn->body_empty_info;
+  int tlen = compile_length_tree(NODE_QUANT_BODY(qn), reg);
 
   if (tlen < 0) return tlen;
 
@@ -744,7 +812,7 @@ compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
   cklen = (CKN_ON ? SIZE_STATE_CHECK_NUM: 0);
 
   /* anychar repeat */
-  if (NTYPE(qn->target) == NT_CANY) {
+  if (NODE_IS_ANYCHAR(NODE_QUANT_BODY(qn))) {
     if (qn->greedy && infinite) {
       if (IS_NOT_NULL(qn->next_head_exact) && !CKN_ON)
         return SIZE_OP_ANYCHAR_STAR_PEEK_NEXT + tlen * qn->lower + cklen;
@@ -753,10 +821,10 @@ compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
     }
   }
 
-  if (empty_info != 0)
-    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
-  else
+  if (empty_info == QUANT_BODY_IS_NOT_EMPTY)
     mod_tlen = tlen;
+  else
+    mod_tlen = tlen + (SIZE_OP_EMPTY_CHECK_START + SIZE_OP_EMPTY_CHECK_END);
 
   if (infinite && qn->lower <= 1) {
     if (qn->greedy) {
@@ -809,33 +877,33 @@ compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
 }
 
 static int
-compile_quantifier_node(QtfrNode* qn, regex_t* reg)
+compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
 {
   int r, mod_tlen;
   int ckn;
   int infinite = IS_REPEAT_INFINITE(qn->upper);
-  int empty_info = qn->target_empty_info;
-  int tlen = compile_length_tree(qn->target, reg);
+  int empty_info = qn->body_empty_info;
+  int tlen = compile_length_tree(NODE_QUANT_BODY(qn), reg);
 
   if (tlen < 0) return tlen;
 
   ckn = ((reg->num_comb_exp_check > 0) ? qn->comb_exp_check_num : 0);
 
   if (is_anychar_star_quantifier(qn)) {
-    r = compile_tree_n_times(qn->target, qn->lower, reg);
-    if (r) return r;
+    r = compile_tree_n_times(NODE_QUANT_BODY(qn), qn->lower, reg, env);
+    if (r != 0) return r;
     if (IS_NOT_NULL(qn->next_head_exact) && !CKN_ON) {
       if (IS_MULTILINE(reg->options))
         r = add_opcode(reg, OP_ANYCHAR_ML_STAR_PEEK_NEXT);
       else
         r = add_opcode(reg, OP_ANYCHAR_STAR_PEEK_NEXT);
-      if (r) return r;
+      if (r != 0) return r;
       if (CKN_ON) {
         r = add_state_check_num(reg, ckn);
-        if (r) return r;
+        if (r != 0) return r;
       }
 
-      return add_bytes(reg, NSTR(qn->next_head_exact)->s, 1);
+      return add_bytes(reg, STR_(qn->next_head_exact)->s, 1);
     }
     else {
       if (IS_MULTILINE(reg->options)) {
@@ -848,7 +916,7 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
                              OP_STATE_CHECK_ANYCHAR_STAR
                              : OP_ANYCHAR_STAR));
       }
-      if (r) return r;
+      if (r != 0) return r;
       if (CKN_ON)
         r = add_state_check_num(reg, ckn);
 
@@ -856,32 +924,32 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
     }
   }
 
-  if (empty_info != 0)
-    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
-  else
+  if (empty_info == QUANT_BODY_IS_NOT_EMPTY)
     mod_tlen = tlen;
+  else
+    mod_tlen = tlen + (SIZE_OP_EMPTY_CHECK_START + SIZE_OP_EMPTY_CHECK_END);
 
   if (infinite && qn->lower <= 1) {
     if (qn->greedy) {
       if (qn->lower == 1) {
         r = add_opcode_rel_addr(reg, OP_JUMP,
                        (CKN_ON ? SIZE_OP_STATE_CHECK_PUSH : SIZE_OP_PUSH));
-        if (r) return r;
+        if (r != 0) return r;
       }
 
       if (CKN_ON) {
         r = add_opcode(reg, OP_STATE_CHECK_PUSH);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_state_check_num(reg, ckn);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_rel_addr(reg, mod_tlen + SIZE_OP_JUMP);
       }
       else {
         r = add_opcode_rel_addr(reg, OP_PUSH, mod_tlen + SIZE_OP_JUMP);
       }
-      if (r) return r;
-      r = compile_tree_empty_check(qn->target, reg, empty_info);
-      if (r) return r;
+      if (r != 0) return r;
+      r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+      if (r != 0) return r;
       r = add_opcode_rel_addr(reg, OP_JUMP,
                 -(mod_tlen + (int )SIZE_OP_JUMP
                 + (int )(CKN_ON ? SIZE_OP_STATE_CHECK_PUSH : SIZE_OP_PUSH)));
@@ -889,15 +957,15 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
     else {
       if (qn->lower == 0) {
         r = add_opcode_rel_addr(reg, OP_JUMP, mod_tlen);
-        if (r) return r;
+        if (r != 0) return r;
       }
-      r = compile_tree_empty_check(qn->target, reg, empty_info);
-      if (r) return r;
+      r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+      if (r != 0) return r;
       if (CKN_ON) {
         r = add_opcode(reg, OP_STATE_CHECK_PUSH_OR_JUMP);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_state_check_num(reg, ckn);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_rel_addr(reg,
                          -(mod_tlen + (int )SIZE_OP_STATE_CHECK_PUSH_OR_JUMP));
       }
@@ -908,8 +976,8 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
   else if (qn->upper == 0) {
     if (qn->is_refered != 0) { /* /(?<n>..){0}/ */
       r = add_opcode_rel_addr(reg, OP_JUMP, tlen);
-      if (r) return r;
-      r = compile_tree(qn->target, reg);
+      if (r != 0) return r;
+      r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
     }
     else
       r = 0;
@@ -918,42 +986,42 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
     if (qn->lower == 0) {
       if (CKN_ON) {
         r = add_opcode(reg, OP_STATE_CHECK_PUSH);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_state_check_num(reg, ckn);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_rel_addr(reg, tlen);
       }
       else {
         r = add_opcode_rel_addr(reg, OP_PUSH, tlen);
       }
-      if (r) return r;
+      if (r != 0) return r;
     }
 
-    r = compile_tree(qn->target, reg);
+    r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
   }
   else if (!qn->greedy && qn->upper == 1 && qn->lower == 0) { /* '??' */
     if (CKN_ON) {
       r = add_opcode(reg, OP_STATE_CHECK_PUSH);
-      if (r) return r;
+      if (r != 0) return r;
       r = add_state_check_num(reg, ckn);
-      if (r) return r;
+      if (r != 0) return r;
       r = add_rel_addr(reg, SIZE_OP_JUMP);
     }
     else {
       r = add_opcode_rel_addr(reg, OP_PUSH, SIZE_OP_JUMP);
     }
 
-    if (r) return r;
+    if (r != 0) return r;
     r = add_opcode_rel_addr(reg, OP_JUMP, tlen);
-    if (r) return r;
-    r = compile_tree(qn->target, reg);
+    if (r != 0) return r;
+    r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
   }
   else {
-    r = compile_range_repeat_node(qn, mod_tlen, empty_info, reg);
+    r = compile_range_repeat_node(qn, mod_tlen, empty_info, reg, env);
     if (CKN_ON) {
-      if (r) return r;
+      if (r != 0) return r;
       r = add_opcode(reg, OP_STATE_CHECK);
-      if (r) return r;
+      if (r != 0) return r;
       r = add_state_check_num(reg, ckn);
     }
   }
@@ -963,17 +1031,17 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
 #else /* USE_COMBINATION_EXPLOSION_CHECK */
 
 static int
-compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
+compile_length_quantifier_node(QuantNode* qn, regex_t* reg)
 {
   int len, mod_tlen;
   int infinite = IS_REPEAT_INFINITE(qn->upper);
-  int empty_info = qn->target_empty_info;
-  int tlen = compile_length_tree(qn->target, reg);
+  int empty_info = qn->body_empty_info;
+  int tlen = compile_length_tree(NODE_QUANT_BODY(qn), reg);
 
   if (tlen < 0) return tlen;
 
   /* anychar repeat */
-  if (NTYPE(qn->target) == NT_CANY) {
+  if (NODE_IS_ANYCHAR(NODE_QUANT_BODY(qn))) {
     if (qn->greedy && infinite) {
       if (IS_NOT_NULL(qn->next_head_exact))
         return SIZE_OP_ANYCHAR_STAR_PEEK_NEXT + tlen * qn->lower;
@@ -982,10 +1050,10 @@ compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
     }
   }
 
-  if (empty_info != 0)
-    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
-  else
+  if (empty_info == QUANT_BODY_IS_NOT_EMPTY)
     mod_tlen = tlen;
+  else
+    mod_tlen = tlen + (SIZE_OP_EMPTY_CHECK_START + SIZE_OP_EMPTY_CHECK_END);
 
   if (infinite &&
       (qn->lower <= 1 || tlen * qn->lower <= QUANTIFIER_EXPAND_LIMIT_SIZE)) {
@@ -1028,25 +1096,25 @@ compile_length_quantifier_node(QtfrNode* qn, regex_t* reg)
 }
 
 static int
-compile_quantifier_node(QtfrNode* qn, regex_t* reg)
+compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
 {
   int i, r, mod_tlen;
   int infinite = IS_REPEAT_INFINITE(qn->upper);
-  int empty_info = qn->target_empty_info;
-  int tlen = compile_length_tree(qn->target, reg);
+  int empty_info = qn->body_empty_info;
+  int tlen = compile_length_tree(NODE_QUANT_BODY(qn), reg);
 
   if (tlen < 0) return tlen;
 
   if (is_anychar_star_quantifier(qn)) {
-    r = compile_tree_n_times(qn->target, qn->lower, reg);
-    if (r) return r;
+    r = compile_tree_n_times(NODE_QUANT_BODY(qn), qn->lower, reg, env);
+    if (r != 0) return r;
     if (IS_NOT_NULL(qn->next_head_exact)) {
       if (IS_MULTILINE(reg->options))
         r = add_opcode(reg, OP_ANYCHAR_ML_STAR_PEEK_NEXT);
       else
         r = add_opcode(reg, OP_ANYCHAR_STAR_PEEK_NEXT);
-      if (r) return r;
-      return add_bytes(reg, NSTR(qn->next_head_exact)->s, 1);
+      if (r != 0) return r;
+      return add_bytes(reg, STR_(qn->next_head_exact)->s, 1);
     }
     else {
       if (IS_MULTILINE(reg->options))
@@ -1056,10 +1124,10 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
     }
   }
 
-  if (empty_info != 0)
-    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
-  else
+  if (empty_info == QUANT_BODY_IS_NOT_EMPTY)
     mod_tlen = tlen;
+  else
+    mod_tlen = tlen + (SIZE_OP_EMPTY_CHECK_START + SIZE_OP_EMPTY_CHECK_END);
 
   if (infinite &&
       (qn->lower <= 1 || tlen * qn->lower <= QUANTIFIER_EXPAND_LIMIT_SIZE)) {
@@ -1075,94 +1143,94 @@ compile_quantifier_node(QtfrNode* qn, regex_t* reg)
       else {
         r = add_opcode_rel_addr(reg, OP_JUMP, SIZE_OP_JUMP);
       }
-      if (r) return r;
+      if (r != 0) return r;
     }
     else {
-      r = compile_tree_n_times(qn->target, qn->lower, reg);
-      if (r) return r;
+      r = compile_tree_n_times(NODE_QUANT_BODY(qn), qn->lower, reg, env);
+      if (r != 0) return r;
     }
 
     if (qn->greedy) {
       if (IS_NOT_NULL(qn->head_exact)) {
         r = add_opcode_rel_addr(reg, OP_PUSH_OR_JUMP_EXACT1,
                                 mod_tlen + SIZE_OP_JUMP);
-        if (r) return r;
-        add_bytes(reg, NSTR(qn->head_exact)->s, 1);
-        r = compile_tree_empty_check(qn->target, reg, empty_info);
-        if (r) return r;
+        if (r != 0) return r;
+        add_bytes(reg, STR_(qn->head_exact)->s, 1);
+        r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+        if (r != 0) return r;
         r = add_opcode_rel_addr(reg, OP_JUMP,
          -(mod_tlen + (int )SIZE_OP_JUMP + (int )SIZE_OP_PUSH_OR_JUMP_EXACT1));
       }
       else if (IS_NOT_NULL(qn->next_head_exact)) {
         r = add_opcode_rel_addr(reg, OP_PUSH_IF_PEEK_NEXT,
                                 mod_tlen + SIZE_OP_JUMP);
-        if (r) return r;
-        add_bytes(reg, NSTR(qn->next_head_exact)->s, 1);
-        r = compile_tree_empty_check(qn->target, reg, empty_info);
-        if (r) return r;
+        if (r != 0) return r;
+        add_bytes(reg, STR_(qn->next_head_exact)->s, 1);
+        r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+        if (r != 0) return r;
         r = add_opcode_rel_addr(reg, OP_JUMP,
           -(mod_tlen + (int )SIZE_OP_JUMP + (int )SIZE_OP_PUSH_IF_PEEK_NEXT));
       }
       else {
         r = add_opcode_rel_addr(reg, OP_PUSH, mod_tlen + SIZE_OP_JUMP);
-        if (r) return r;
-        r = compile_tree_empty_check(qn->target, reg, empty_info);
-        if (r) return r;
+        if (r != 0) return r;
+        r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+        if (r != 0) return r;
         r = add_opcode_rel_addr(reg, OP_JUMP,
                    -(mod_tlen + (int )SIZE_OP_JUMP + (int )SIZE_OP_PUSH));
       }
     }
     else {
       r = add_opcode_rel_addr(reg, OP_JUMP, mod_tlen);
-      if (r) return r;
-      r = compile_tree_empty_check(qn->target, reg, empty_info);
-      if (r) return r;
+      if (r != 0) return r;
+      r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, empty_info, env);
+      if (r != 0) return r;
       r = add_opcode_rel_addr(reg, OP_PUSH, -(mod_tlen + (int )SIZE_OP_PUSH));
     }
   }
   else if (qn->upper == 0 && qn->is_refered != 0) { /* /(?<n>..){0}/ */
     r = add_opcode_rel_addr(reg, OP_JUMP, tlen);
-    if (r) return r;
-    r = compile_tree(qn->target, reg);
+    if (r != 0) return r;
+    r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
   }
   else if (!infinite && qn->greedy &&
            (qn->upper == 1 || (tlen + SIZE_OP_PUSH) * qn->upper
                                   <= QUANTIFIER_EXPAND_LIMIT_SIZE)) {
     int n = qn->upper - qn->lower;
 
-    r = compile_tree_n_times(qn->target, qn->lower, reg);
-    if (r) return r;
+    r = compile_tree_n_times(NODE_QUANT_BODY(qn), qn->lower, reg, env);
+    if (r != 0) return r;
 
     for (i = 0; i < n; i++) {
       r = add_opcode_rel_addr(reg, OP_PUSH,
 			   (n - i) * tlen + (n - i - 1) * SIZE_OP_PUSH);
-      if (r) return r;
-      r = compile_tree(qn->target, reg);
-      if (r) return r;
+      if (r != 0) return r;
+      r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
+      if (r != 0) return r;
     }
   }
   else if (!qn->greedy && qn->upper == 1 && qn->lower == 0) { /* '??' */
     r = add_opcode_rel_addr(reg, OP_PUSH, SIZE_OP_JUMP);
-    if (r) return r;
+    if (r != 0) return r;
     r = add_opcode_rel_addr(reg, OP_JUMP, tlen);
-    if (r) return r;
-    r = compile_tree(qn->target, reg);
+    if (r != 0) return r;
+    r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
   }
   else {
-    r = compile_range_repeat_node(qn, mod_tlen, empty_info, reg);
+    r = compile_range_repeat_node(qn, mod_tlen, empty_info, reg, env);
   }
   return r;
 }
 #endif /* USE_COMBINATION_EXPLOSION_CHECK */
 
 static int
-compile_length_option_node(EncloseNode* node, regex_t* reg)
+compile_length_option_node(EnclosureNode* node, regex_t* reg)
 {
   int tlen;
   OnigOptionType prev = reg->options;
 
-  reg->options = node->option;
-  tlen = compile_length_tree(node->target, reg);
+  reg->options = node->o.option;
+  tlen = compile_length_tree(NODE_ENCLOSURE_BODY(node), reg);
   reg->options = prev;
 
   if (tlen < 0) return tlen;
@@ -1176,82 +1244,88 @@ compile_length_option_node(EncloseNode* node, regex_t* reg)
 }
 
 static int
-compile_option_node(EncloseNode* node, regex_t* reg)
+compile_option_node(EnclosureNode* node, regex_t* reg, ScanEnv* env)
 {
   int r;
   OnigOptionType prev = reg->options;
 
-  if (IS_DYNAMIC_OPTION(prev ^ node->option)) {
-    r = add_opcode_option(reg, OP_SET_OPTION_PUSH, node->option);
-    if (r) return r;
+  if (IS_DYNAMIC_OPTION(prev ^ node->o.option)) {
+    r = add_opcode_option(reg, OP_SET_OPTION_PUSH, node->o.option);
+    if (r != 0) return r;
     r = add_opcode_option(reg, OP_SET_OPTION, prev);
-    if (r) return r;
+    if (r != 0) return r;
     r = add_opcode(reg, OP_FAIL);
-    if (r) return r;
+    if (r != 0) return r;
   }
 
-  reg->options = node->option;
-  r = compile_tree(node->target, reg);
+  reg->options = node->o.option;
+  r = compile_tree(NODE_ENCLOSURE_BODY(node), reg, env);
   reg->options = prev;
 
-  if (IS_DYNAMIC_OPTION(prev ^ node->option)) {
-    if (r) return r;
+  if (IS_DYNAMIC_OPTION(prev ^ node->o.option)) {
+    if (r != 0) return r;
     r = add_opcode_option(reg, OP_SET_OPTION, prev);
   }
   return r;
 }
 
 static int
-compile_length_enclose_node(EncloseNode* node, regex_t* reg)
+compile_length_enclosure_node(EnclosureNode* node, regex_t* reg)
 {
   int len;
   int tlen;
 
-  if (node->type == ENCLOSE_OPTION)
+  if (node->type == ENCLOSURE_OPTION)
     return compile_length_option_node(node, reg);
 
-  if (node->target) {
-    tlen = compile_length_tree(node->target, reg);
+  if (NODE_ENCLOSURE_BODY(node)) {
+    tlen = compile_length_tree(NODE_ENCLOSURE_BODY(node), reg);
     if (tlen < 0) return tlen;
   }
   else
     tlen = 0;
 
   switch (node->type) {
-  case ENCLOSE_MEMORY:
+  case ENCLOSURE_MEMORY:
 #ifdef USE_SUBEXP_CALL
-    if (IS_ENCLOSE_CALLED(node)) {
+
+    if (node->m.regnum == 0 && NODE_IS_CALLED(node)) {
+      len = tlen + SIZE_OP_CALL + SIZE_OP_JUMP + SIZE_OP_RETURN;
+      return len;
+    }
+
+    if (NODE_IS_CALLED(node)) {
       len = SIZE_OP_MEMORY_START_PUSH + tlen
         + SIZE_OP_CALL + SIZE_OP_JUMP + SIZE_OP_RETURN;
-      if (BIT_STATUS_AT(reg->bt_mem_end, node->regnum))
-        len += (IS_ENCLOSE_RECURSION(node)
+      if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+        len += (NODE_IS_RECURSION(node)
                 ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_PUSH);
       else
-        len += (IS_ENCLOSE_RECURSION(node)
+        len += (NODE_IS_RECURSION(node)
                 ? SIZE_OP_MEMORY_END_REC : SIZE_OP_MEMORY_END);
     }
-    else if (IS_ENCLOSE_RECURSION(node)) {
+    else if (NODE_IS_RECURSION(node)) {
       len = SIZE_OP_MEMORY_START_PUSH;
-      len += tlen + (BIT_STATUS_AT(reg->bt_mem_end, node->regnum)
+      len += tlen + (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum)
                      ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_REC);
     }
     else
 #endif
     {
-      if (BIT_STATUS_AT(reg->bt_mem_start, node->regnum))
+      if (MEM_STATUS_AT0(reg->bt_mem_start, node->m.regnum))
         len = SIZE_OP_MEMORY_START_PUSH;
       else
         len = SIZE_OP_MEMORY_START;
 
-      len += tlen + (BIT_STATUS_AT(reg->bt_mem_end, node->regnum)
+      len += tlen + (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum)
 		     ? SIZE_OP_MEMORY_END_PUSH : SIZE_OP_MEMORY_END);
     }
     break;
 
-  case ENCLOSE_STOP_BACKTRACK:
-    if (IS_ENCLOSE_STOP_BT_SIMPLE_REPEAT(node)) {
-      QtfrNode* qn = NQTFR(node->target);
-      tlen = compile_length_tree(qn->target, reg);
+  case ENCLOSURE_STOP_BACKTRACK:
+    if (NODE_IS_STOP_BT_SIMPLE_REPEAT(node)) {
+      QuantNode* qn = QUANT_(NODE_ENCLOSURE_BODY(node));
+      tlen = compile_length_tree(NODE_QUANT_BODY(qn), reg);
       if (tlen < 0) return tlen;
 
       len = tlen * qn->lower
@@ -1273,102 +1347,124 @@ compile_length_enclose_node(EncloseNode* node, regex_t* reg)
 static int get_char_length_tree(Node* node, regex_t* reg, int* len);
 
 static int
-compile_enclose_node(EncloseNode* node, regex_t* reg)
+compile_enclosure_memory_node(EnclosureNode* node, regex_t* reg, ScanEnv* env)
 {
-  int r, len;
+  int r;
+  int len;
 
-  if (node->type == ENCLOSE_OPTION)
-    return compile_option_node(node, reg);
+#ifdef USE_SUBEXP_CALL
+  if (node->m.regnum == 0 && NODE_IS_CALLED(node)) {
+    r = add_opcode(reg, OP_CALL);
+    if (r != 0) return r;
+    node->m.called_addr = BBUF_GET_OFFSET_POS(reg) + SIZE_ABSADDR + SIZE_OP_JUMP;
+    NODE_STATUS_ADD(node, NST_ADDR_FIXED);
+    r = add_abs_addr(reg, (int )node->m.called_addr);
+    if (r != 0) return r;
+    len = compile_length_tree(NODE_ENCLOSURE_BODY(node), reg);
+    len += SIZE_OP_RETURN;
+    r = add_opcode_rel_addr(reg, OP_JUMP, len);
+    if (r != 0) return r;
+
+    r = compile_tree(NODE_ENCLOSURE_BODY(node), reg, env);
+    if (r != 0) return r;
+    r = add_opcode(reg, OP_RETURN);
+    return r;
+  }
+#endif
 
-  switch (node->type) {
-  case ENCLOSE_MEMORY:
 #ifdef USE_SUBEXP_CALL
-    if (IS_ENCLOSE_CALLED(node)) {
-      r = add_opcode(reg, OP_CALL);
-      if (r) return r;
-      node->call_addr = BBUF_GET_OFFSET_POS(reg) + SIZE_ABSADDR + SIZE_OP_JUMP;
-      node->state |= NST_ADDR_FIXED;
-      r = add_abs_addr(reg, (int )node->call_addr);
-      if (r) return r;
-      len = compile_length_tree(node->target, reg);
-      len += (SIZE_OP_MEMORY_START_PUSH + SIZE_OP_RETURN);
-      if (BIT_STATUS_AT(reg->bt_mem_end, node->regnum))
-        len += (IS_ENCLOSE_RECURSION(node)
-                ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_PUSH);
-      else
-        len += (IS_ENCLOSE_RECURSION(node)
-                ? SIZE_OP_MEMORY_END_REC : SIZE_OP_MEMORY_END);
+  if (NODE_IS_CALLED(node)) {
+    r = add_opcode(reg, OP_CALL);
+    if (r != 0) return r;
+    node->m.called_addr = BBUF_GET_OFFSET_POS(reg) + SIZE_ABSADDR + SIZE_OP_JUMP;
+    NODE_STATUS_ADD(node, NST_ADDR_FIXED);
+    r = add_abs_addr(reg, (int )node->m.called_addr);
+    if (r != 0) return r;
+    len = compile_length_tree(NODE_ENCLOSURE_BODY(node), reg);
+    len += (SIZE_OP_MEMORY_START_PUSH + SIZE_OP_RETURN);
+    if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+      len += (NODE_IS_RECURSION(node)
+              ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_PUSH);
+    else
+      len += (NODE_IS_RECURSION(node)
+              ? SIZE_OP_MEMORY_END_REC : SIZE_OP_MEMORY_END);
 
-      r = add_opcode_rel_addr(reg, OP_JUMP, len);
-      if (r) return r;
-    }
+    r = add_opcode_rel_addr(reg, OP_JUMP, len);
+    if (r != 0) return r;
+  }
 #endif
-    if (BIT_STATUS_AT(reg->bt_mem_start, node->regnum))
-      r = add_opcode(reg, OP_MEMORY_START_PUSH);
-    else
-      r = add_opcode(reg, OP_MEMORY_START);
-    if (r) return r;
-    r = add_mem_num(reg, node->regnum);
-    if (r) return r;
-    r = compile_tree(node->target, reg);
-    if (r) return r;
-#ifdef USE_SUBEXP_CALL
-    if (IS_ENCLOSE_CALLED(node)) {
-      if (BIT_STATUS_AT(reg->bt_mem_end, node->regnum))
-        r = add_opcode(reg, (IS_ENCLOSE_RECURSION(node)
-                             ? OP_MEMORY_END_PUSH_REC : OP_MEMORY_END_PUSH));
-      else
-        r = add_opcode(reg, (IS_ENCLOSE_RECURSION(node)
-                             ? OP_MEMORY_END_REC : OP_MEMORY_END));
 
-      if (r) return r;
-      r = add_mem_num(reg, node->regnum);
-      if (r) return r;
-      r = add_opcode(reg, OP_RETURN);
-    }
-    else if (IS_ENCLOSE_RECURSION(node)) {
-      if (BIT_STATUS_AT(reg->bt_mem_end, node->regnum))
-        r = add_opcode(reg, OP_MEMORY_END_PUSH_REC);
-      else
-        r = add_opcode(reg, OP_MEMORY_END_REC);
-      if (r) return r;
-      r = add_mem_num(reg, node->regnum);
-    }
-    else
+  if (MEM_STATUS_AT0(reg->bt_mem_start, node->m.regnum))
+    r = add_opcode(reg, OP_MEMORY_START_PUSH);
+  else
+    r = add_opcode(reg, OP_MEMORY_START);
+  if (r != 0) return r;
+  r = add_mem_num(reg, node->m.regnum);
+  if (r != 0) return r;
+  r = compile_tree(NODE_ENCLOSURE_BODY(node), reg, env);
+  if (r != 0) return r;
+
+#ifdef USE_SUBEXP_CALL
+  if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+    r = add_opcode(reg, (NODE_IS_RECURSION(node)
+                         ? OP_MEMORY_END_PUSH_REC : OP_MEMORY_END_PUSH));
+  else
+    r = add_opcode(reg, (NODE_IS_RECURSION(node)
+                         ? OP_MEMORY_END_REC : OP_MEMORY_END));
+  if (r != 0) return r;
+  r = add_mem_num(reg, node->m.regnum);
+  if (NODE_IS_CALLED(node)) {
+    if (r != 0) return r;
+    r = add_opcode(reg, OP_RETURN);
+  }
+#else
+  if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+    r = add_opcode(reg, OP_MEMORY_END_PUSH);
+  else
+    r = add_opcode(reg, OP_MEMORY_END);
+  if (r != 0) return r;
+  r = add_mem_num(reg, node->m.regnum);
 #endif
-    {
-      if (BIT_STATUS_AT(reg->bt_mem_end, node->regnum))
-        r = add_opcode(reg, OP_MEMORY_END_PUSH);
-      else
-        r = add_opcode(reg, OP_MEMORY_END);
-      if (r) return r;
-      r = add_mem_num(reg, node->regnum);
-    }
+
+  return r;
+}
+
+static int
+compile_enclosure_node(EnclosureNode* node, regex_t* reg, ScanEnv* env)
+{
+  int r, len;
+
+  if (node->type == ENCLOSURE_OPTION)
+    return compile_option_node(node, reg, env);
+
+  switch (node->type) {
+  case ENCLOSURE_MEMORY:
+    r = compile_enclosure_memory_node(node, reg, env);
     break;
 
-  case ENCLOSE_STOP_BACKTRACK:
-    if (IS_ENCLOSE_STOP_BT_SIMPLE_REPEAT(node)) {
-      QtfrNode* qn = NQTFR(node->target);
-      r = compile_tree_n_times(qn->target, qn->lower, reg);
-      if (r) return r;
+  case ENCLOSURE_STOP_BACKTRACK:
+    if (NODE_IS_STOP_BT_SIMPLE_REPEAT(node)) {
+      QuantNode* qn = QUANT_(NODE_ENCLOSURE_BODY(node));
+      r = compile_tree_n_times(NODE_QUANT_BODY(qn), qn->lower, reg, env);
+      if (r != 0) return r;
 
-      len = compile_length_tree(qn->target, reg);
+      len = compile_length_tree(NODE_QUANT_BODY(qn), reg);
       if (len < 0) return len;
 
       r = add_opcode_rel_addr(reg, OP_PUSH, len + SIZE_OP_POP + SIZE_OP_JUMP);
-      if (r) return r;
-      r = compile_tree(qn->target, reg);
-      if (r) return r;
+      if (r != 0) return r;
+      r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
+      if (r != 0) return r;
       r = add_opcode(reg, OP_POP);
-      if (r) return r;
+      if (r != 0) return r;
       r = add_opcode_rel_addr(reg, OP_JUMP,
              -((int )SIZE_OP_PUSH + len + (int )SIZE_OP_POP + (int )SIZE_OP_JUMP));
     }
     else {
       r = add_opcode(reg, OP_PUSH_STOP_BT);
-      if (r) return r;
-      r = compile_tree(node->target, reg);
-      if (r) return r;
+      if (r != 0) return r;
+      r = compile_tree(NODE_ENCLOSURE_BODY(node), reg, env);
+      if (r != 0) return r;
       r = add_opcode(reg, OP_POP_STOP_BT);
     }
     break;
@@ -1387,8 +1483,8 @@ compile_length_anchor_node(AnchorNode* node, regex_t* reg)
   int len;
   int tlen = 0;
 
-  if (node->target) {
-    tlen = compile_length_tree(node->target, reg);
+  if (IS_NOT_NULL(NODE_ANCHOR_BODY(node))) {
+    tlen = compile_length_tree(NODE_ANCHOR_BODY(node), reg);
     if (tlen < 0) return tlen;
   }
 
@@ -1415,7 +1511,7 @@ compile_length_anchor_node(AnchorNode* node, regex_t* reg)
 }
 
 static int
-compile_anchor_node(AnchorNode* node, regex_t* reg)
+compile_anchor_node(AnchorNode* node, regex_t* reg, ScanEnv* env)
 {
   int r, len;
 
@@ -1436,19 +1532,19 @@ compile_anchor_node(AnchorNode* node, regex_t* reg)
 
   case ANCHOR_PREC_READ:
     r = add_opcode(reg, OP_PUSH_POS);
-    if (r) return r;
-    r = compile_tree(node->target, reg);
-    if (r) return r;
+    if (r != 0) return r;
+    r = compile_tree(NODE_ANCHOR_BODY(node), reg, env);
+    if (r != 0) return r;
     r = add_opcode(reg, OP_POP_POS);
     break;
 
   case ANCHOR_PREC_READ_NOT:
-    len = compile_length_tree(node->target, reg);
+    len = compile_length_tree(NODE_ANCHOR_BODY(node), reg);
     if (len < 0) return len;
     r = add_opcode_rel_addr(reg, OP_PUSH_POS_NOT, len + SIZE_OP_FAIL_POS);
-    if (r) return r;
-    r = compile_tree(node->target, reg);
-    if (r) return r;
+    if (r != 0) return r;
+    r = compile_tree(NODE_ANCHOR_BODY(node), reg, env);
+    if (r != 0) return r;
     r = add_opcode(reg, OP_FAIL_POS);
     break;
 
@@ -1456,37 +1552,37 @@ compile_anchor_node(AnchorNode* node, regex_t* reg)
     {
       int n;
       r = add_opcode(reg, OP_LOOK_BEHIND);
-      if (r) return r;
+      if (r != 0) return r;
       if (node->char_len < 0) {
-        r = get_char_length_tree(node->target, reg, &n);
-        if (r) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
+        r = get_char_length_tree(NODE_ANCHOR_BODY(node), reg, &n);
+        if (r != 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
       }
       else
         n = node->char_len;
 
       r = add_length(reg, n);
-      if (r) return r;
-      r = compile_tree(node->target, reg);
+      if (r != 0) return r;
+      r = compile_tree(NODE_ANCHOR_BODY(node), reg, env);
     }
     break;
 
   case ANCHOR_LOOK_BEHIND_NOT:
     {
       int n;
-      len = compile_length_tree(node->target, reg);
+      len = compile_length_tree(NODE_ANCHOR_BODY(node), reg);
       r = add_opcode_rel_addr(reg, OP_PUSH_LOOK_BEHIND_NOT,
 			   len + SIZE_OP_FAIL_LOOK_BEHIND_NOT);
-      if (r) return r;
+      if (r != 0) return r;
       if (node->char_len < 0) {
-        r = get_char_length_tree(node->target, reg, &n);
-        if (r) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
+        r = get_char_length_tree(NODE_ANCHOR_BODY(node), reg, &n);
+        if (r != 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
       }
       else
         n = node->char_len;
       r = add_length(reg, n);
-      if (r) return r;
-      r = compile_tree(node->target, reg);
-      if (r) return r;
+      if (r != 0) return r;
+      r = compile_tree(NODE_ANCHOR_BODY(node), reg, env);
+      if (r != 0) return r;
       r = add_opcode(reg, OP_FAIL_LOOK_BEHIND_NOT);
     }
     break;
@@ -1502,55 +1598,53 @@ compile_anchor_node(AnchorNode* node, regex_t* reg)
 static int
 compile_length_tree(Node* node, regex_t* reg)
 {
-  int len, type, r;
+  int len, r;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     len = 0;
     do {
-      r = compile_length_tree(NCAR(node), reg);
+      r = compile_length_tree(NODE_CAR(node), reg);
       if (r < 0) return r;
       len += r;
-    } while (IS_NOT_NULL(node = NCDR(node)));
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     r = len;
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       int n;
 
       n = r = 0;
       do {
-        r += compile_length_tree(NCAR(node), reg);
+        r += compile_length_tree(NODE_CAR(node), reg);
         n++;
-      } while (IS_NOT_NULL(node = NCDR(node)));
+      } while (IS_NOT_NULL(node = NODE_CDR(node)));
       r += (SIZE_OP_PUSH + SIZE_OP_JUMP) * (n - 1);
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     if (NSTRING_IS_RAW(node))
-      r = compile_length_string_raw_node(NSTR(node), reg);
+      r = compile_length_string_raw_node(STR_(node), reg);
     else
       r = compile_length_string_node(node, reg);
     break;
 
-  case NT_CCLASS:
-    r = compile_length_cclass_node(NCCLASS(node), reg);
+  case NODE_CCLASS:
+    r = compile_length_cclass_node(CCLASS_(node), reg);
     break;
 
-  case NT_CTYPE:
-  case NT_CANY:
+  case NODE_CTYPE:
     r = SIZE_OPCODE;
     break;
 
-  case NT_BREF:
+  case NODE_BREF:
     {
-      BRefNode* br = NBREF(node);
+      BRefNode* br = BREF_(node);
 
 #ifdef USE_BACKREF_WITH_LEVEL
-      if (IS_BACKREF_NEST_LEVEL(br)) {
+      if (NODE_IS_NEST_LEVEL(node)) {
         r = SIZE_OPCODE + SIZE_OPTION + SIZE_LENGTH +
             SIZE_LENGTH + (SIZE_MEMNUM * br->back_num);
       }
@@ -1567,21 +1661,21 @@ compile_length_tree(Node* node, regex_t* reg)
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
+  case NODE_CALL:
     r = SIZE_OP_CALL;
     break;
 #endif
 
-  case NT_QTFR:
-    r = compile_length_quantifier_node(NQTFR(node), reg);
+  case NODE_QUANT:
+    r = compile_length_quantifier_node(QUANT_(node), reg);
     break;
 
-  case NT_ENCLOSE:
-    r = compile_length_enclose_node(NENCLOSE(node), reg);
+  case NODE_ENCLOSURE:
+    r = compile_length_enclosure_node(ENCLOSURE_(node), reg);
     break;
 
-  case NT_ANCHOR:
-    r = compile_length_anchor_node(NANCHOR(node), reg);
+  case NODE_ANCHOR:
+    r = compile_length_anchor_node(ANCHOR_(node), reg);
     break;
 
   default:
@@ -1593,94 +1687,95 @@ compile_length_tree(Node* node, regex_t* reg)
 }
 
 static int
-compile_tree(Node* node, regex_t* reg)
+compile_tree(Node* node, regex_t* reg, ScanEnv* env)
 {
-  int n, type, len, pos, r = 0;
+  int n, len, pos, r = 0;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     do {
-      r = compile_tree(NCAR(node), reg);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      r = compile_tree(NODE_CAR(node), reg, env);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       Node* x = node;
       len = 0;
       do {
-        len += compile_length_tree(NCAR(x), reg);
-        if (NCDR(x) != NULL) {
+        len += compile_length_tree(NODE_CAR(x), reg);
+        if (IS_NOT_NULL(NODE_CDR(x))) {
           len += SIZE_OP_PUSH + SIZE_OP_JUMP;
         }
-      } while (IS_NOT_NULL(x = NCDR(x)));
+      } while (IS_NOT_NULL(x = NODE_CDR(x)));
       pos = reg->used + len;  /* goal position */
 
       do {
-        len = compile_length_tree(NCAR(node), reg);
-        if (IS_NOT_NULL(NCDR(node))) {
+        len = compile_length_tree(NODE_CAR(node), reg);
+        if (IS_NOT_NULL(NODE_CDR(node))) {
           r = add_opcode_rel_addr(reg, OP_PUSH, len + SIZE_OP_JUMP);
-          if (r) break;
+          if (r != 0) break;
         }
-        r = compile_tree(NCAR(node), reg);
-        if (r) break;
-        if (IS_NOT_NULL(NCDR(node))) {
+        r = compile_tree(NODE_CAR(node), reg, env);
+        if (r != 0) break;
+        if (IS_NOT_NULL(NODE_CDR(node))) {
           len = pos - (reg->used + SIZE_OP_JUMP);
           r = add_opcode_rel_addr(reg, OP_JUMP, len);
-          if (r) break;
+          if (r != 0) break;
         }
-      } while (IS_NOT_NULL(node = NCDR(node)));
+      } while (IS_NOT_NULL(node = NODE_CDR(node)));
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     if (NSTRING_IS_RAW(node))
-      r = compile_string_raw_node(NSTR(node), reg);
+      r = compile_string_raw_node(STR_(node), reg);
     else
       r = compile_string_node(node, reg);
     break;
 
-  case NT_CCLASS:
-    r = compile_cclass_node(NCCLASS(node), reg);
+  case NODE_CCLASS:
+    r = compile_cclass_node(CCLASS_(node), reg);
     break;
 
-  case NT_CTYPE:
+  case NODE_CTYPE:
     {
       int op;
 
-      switch (NCTYPE(node)->ctype) {
+      switch (CTYPE_(node)->ctype) {
+      case CTYPE_ANYCHAR:
+        if (IS_MULTILINE(reg->options))
+          r = add_opcode(reg, OP_ANYCHAR_ML);
+        else
+          r = add_opcode(reg, OP_ANYCHAR);
+        break;
+
       case ONIGENC_CTYPE_WORD:
-        if (NCTYPE(node)->not != 0)  op = OP_NOT_WORD;
+        if (CTYPE_(node)->not != 0)  op = OP_NOT_WORD;
         else                         op = OP_WORD;
+
+        r = add_opcode(reg, op);
         break;
+
       default:
         return ONIGERR_TYPE_BUG;
         break;
       }
-      r = add_opcode(reg, op);
     }
     break;
 
-  case NT_CANY:
-    if (IS_MULTILINE(reg->options))
-      r = add_opcode(reg, OP_ANYCHAR_ML);
-    else
-      r = add_opcode(reg, OP_ANYCHAR);
-    break;
-
-  case NT_BREF:
+  case NODE_BREF:
     {
-      BRefNode* br = NBREF(node);
+      BRefNode* br = BREF_(node);
 
 #ifdef USE_BACKREF_WITH_LEVEL
-      if (IS_BACKREF_NEST_LEVEL(br)) {
+      if (NODE_IS_NEST_LEVEL(node)) {
         r = add_opcode(reg, OP_BACKREF_WITH_LEVEL);
-        if (r) return r;
+        if (r != 0) return r;
         r = add_option(reg, (reg->options & ONIG_OPTION_IGNORECASE));
-        if (r) return r;
+        if (r != 0) return r;
         r = add_length(reg, br->nest_level);
-        if (r) return r;
+        if (r != 0) return r;
 
         goto add_bacref_mems;
       }
@@ -1690,7 +1785,7 @@ compile_tree(Node* node, regex_t* reg)
         n = br->back_static[0];
         if (IS_IGNORECASE(reg->options)) {
           r = add_opcode(reg, OP_BACKREFN_IC);
-          if (r) return r;
+          if (r != 0) return r;
           r = add_mem_num(reg, n);
         }
         else {
@@ -1699,7 +1794,7 @@ compile_tree(Node* node, regex_t* reg)
           case 2:  r = add_opcode(reg, OP_BACKREF2); break;
           default:
             r = add_opcode(reg, OP_BACKREFN);
-            if (r) return r;
+            if (r != 0) return r;
             r = add_mem_num(reg, n);
             break;
           }
@@ -1715,43 +1810,43 @@ compile_tree(Node* node, regex_t* reg)
         else {
           r = add_opcode(reg, OP_BACKREF_MULTI);
         }
-        if (r) return r;
+        if (r != 0) return r;
 
 #ifdef USE_BACKREF_WITH_LEVEL
       add_bacref_mems:
 #endif
         r = add_length(reg, br->back_num);
-        if (r) return r;
+        if (r != 0) return r;
         p = BACKREFS_P(br);
         for (i = br->back_num - 1; i >= 0; i--) {
           r = add_mem_num(reg, p[i]);
-          if (r) return r;
+          if (r != 0) return r;
         }
       }
     }
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    r = compile_call(NCALL(node), reg);
+  case NODE_CALL:
+    r = compile_call(CALL_(node), reg, env);
     break;
 #endif
 
-  case NT_QTFR:
-    r = compile_quantifier_node(NQTFR(node), reg);
+  case NODE_QUANT:
+    r = compile_quantifier_node(QUANT_(node), reg, env);
     break;
 
-  case NT_ENCLOSE:
-    r = compile_enclose_node(NENCLOSE(node), reg);
+  case NODE_ENCLOSURE:
+    r = compile_enclosure_node(ENCLOSURE_(node), reg, env);
     break;
 
-  case NT_ANCHOR:
-    r = compile_anchor_node(NANCHOR(node), reg);
+  case NODE_ANCHOR:
+    r = compile_anchor_node(ANCHOR_(node), reg, env);
     break;
 
   default:
 #ifdef ONIG_DEBUG
-    fprintf(stderr, "compile_tree: undefined node type %d\n", NTYPE(node));
+    fprintf(stderr, "compile_tree: undefined node type %d\n", NODE_TYPE(node));
 #endif
     break;
   }
@@ -1767,50 +1862,50 @@ noname_disable_map(Node** plink, GroupNumRemap* map, int* counter)
   int r = 0;
   Node* node = *plink;
 
-  switch (NTYPE(node)) {
-  case NT_LIST:
-  case NT_ALT:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     do {
-      r = noname_disable_map(&(NCAR(node)), map, counter);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      r = noname_disable_map(&(NODE_CAR(node)), map, counter);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
-      Node** ptarget = &(NQTFR(node)->target);
+      Node** ptarget = &(NODE_BODY(node));
       Node*  old = *ptarget;
       r = noname_disable_map(ptarget, map, counter);
-      if (*ptarget != old && NTYPE(*ptarget) == NT_QTFR) {
+      if (*ptarget != old && NODE_TYPE(*ptarget) == NODE_QUANT) {
         onig_reduce_nested_quantifier(node, *ptarget);
       }
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
-      if (en->type == ENCLOSE_MEMORY) {
-        if (IS_ENCLOSE_NAMED_GROUP(en)) {
+      EnclosureNode* en = ENCLOSURE_(node);
+      if (en->type == ENCLOSURE_MEMORY) {
+        if (NODE_IS_NAMED_GROUP(node)) {
           (*counter)++;
-          map[en->regnum].new_val = *counter;
-          en->regnum = *counter;
-          r = noname_disable_map(&(en->target), map, counter);
+          map[en->m.regnum].new_val = *counter;
+          en->m.regnum = *counter;
+          r = noname_disable_map(&(NODE_BODY(node)), map, counter);
         }
         else {
-          *plink = en->target;
-          en->target = NULL_NODE;
+          *plink = NODE_BODY(node);
+          NODE_BODY(node) = NULL_NODE;
           onig_node_free(node);
           r = noname_disable_map(plink, map, counter);
         }
       }
       else
-        r = noname_disable_map(&(en->target), map, counter);
+        r = noname_disable_map(&(NODE_BODY(node)), map, counter);
     }
     break;
 
-  case NT_ANCHOR:
-    if (NANCHOR(node)->target)
-      r = noname_disable_map(&(NANCHOR(node)->target), map, counter);
+  case NODE_ANCHOR:
+    if (IS_NOT_NULL(NODE_BODY(node)))
+      r = noname_disable_map(&(NODE_BODY(node)), map, counter);
     break;
 
   default:
@@ -1825,9 +1920,9 @@ renumber_node_backref(Node* node, GroupNumRemap* map)
 {
   int i, pos, n, old_num;
   int *backs;
-  BRefNode* bn = NBREF(node);
+  BRefNode* bn = BREF_(node);
 
-  if (! IS_BACKREF_NAME_REF(bn))
+  if (! NODE_IS_BY_NAME(node))
     return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;
 
   old_num = bn->back_num;
@@ -1853,27 +1948,26 @@ renumber_by_map(Node* node, GroupNumRemap* map)
 {
   int r = 0;
 
-  switch (NTYPE(node)) {
-  case NT_LIST:
-  case NT_ALT:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     do {
-      r = renumber_by_map(NCAR(node), map);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      r = renumber_by_map(NODE_CAR(node), map);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
-  case NT_QTFR:
-    r = renumber_by_map(NQTFR(node)->target, map);
-    break;
-  case NT_ENCLOSE:
-    r = renumber_by_map(NENCLOSE(node)->target, map);
+
+  case NODE_QUANT:
+  case NODE_ENCLOSURE:
+    r = renumber_by_map(NODE_BODY(node), map);
     break;
 
-  case NT_BREF:
+  case NODE_BREF:
     r = renumber_node_backref(node, map);
     break;
 
-  case NT_ANCHOR:
-    if (NANCHOR(node)->target)
-      r = renumber_by_map(NANCHOR(node)->target, map);
+  case NODE_ANCHOR:
+    if (IS_NOT_NULL(NODE_BODY(node)))
+      r = renumber_by_map(NODE_BODY(node), map);
     break;
 
   default:
@@ -1888,28 +1982,26 @@ numbered_ref_check(Node* node)
 {
   int r = 0;
 
-  switch (NTYPE(node)) {
-  case NT_LIST:
-  case NT_ALT:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     do {
-      r = numbered_ref_check(NCAR(node));
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
-    break;
-  case NT_QTFR:
-    r = numbered_ref_check(NQTFR(node)->target);
-    break;
-  case NT_ENCLOSE:
-    r = numbered_ref_check(NENCLOSE(node)->target);
+      r = numbered_ref_check(NODE_CAR(node));
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_BREF:
-    if (! IS_BACKREF_NAME_REF(NBREF(node)))
-      return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;
+  case NODE_ANCHOR:
+    if (IS_NULL(NODE_BODY(node)))
+      break;
+    /* fall */
+  case NODE_QUANT:
+  case NODE_ENCLOSURE:
+    r = numbered_ref_check(NODE_BODY(node));
     break;
 
-  case NT_ANCHOR:
-    if (NANCHOR(node)->target)
-      r = numbered_ref_check(NANCHOR(node)->target);
+  case NODE_BREF:
+    if (! NODE_IS_BY_NAME(node))
+      return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;
     break;
 
   default:
@@ -1923,7 +2015,7 @@ static int
 disable_noname_group_capture(Node** root, regex_t* reg, ScanEnv* env)
 {
   int r, i, pos, counter;
-  BitStatusType loc;
+  MemStatusType loc;
   GroupNumRemap* map;
 
   map = (GroupNumRemap* )xalloca(sizeof(GroupNumRemap) * (env->num_mem + 1));
@@ -1940,16 +2032,16 @@ disable_noname_group_capture(Node** root, regex_t* reg, ScanEnv* env)
 
   for (i = 1, pos = 1; i <= env->num_mem; i++) {
     if (map[i].new_val > 0) {
-      SCANENV_MEM_NODES(env)[pos] = SCANENV_MEM_NODES(env)[i];
+      SCANENV_MEMENV(env)[pos] = SCANENV_MEMENV(env)[i];
       pos++;
     }
   }
 
   loc = env->capture_history;
-  BIT_STATUS_CLEAR(env->capture_history);
+  MEM_STATUS_CLEAR(env->capture_history);
   for (i = 1; i <= ONIG_MAX_CAPTURE_HISTORY_GROUP; i++) {
-    if (BIT_STATUS_AT(loc, i)) {
-      BIT_STATUS_ON_AT_SIMPLE(env->capture_history, map[i].new_val);
+    if (MEM_STATUS_AT(loc, i)) {
+      MEM_STATUS_ON_SIMPLE(env->capture_history, map[i].new_val);
     }
   }
 
@@ -1965,13 +2057,13 @@ static int
 unset_addr_list_fix(UnsetAddrList* uslist, regex_t* reg)
 {
   int i, offset;
-  EncloseNode* en;
+  EnclosureNode* en;
   AbsAddrType addr;
 
   for (i = 0; i < uslist->num; i++) {
-    en = NENCLOSE(uslist->us[i].target);
-    if (! IS_ENCLOSE_ADDR_FIXED(en)) return ONIGERR_PARSER_BUG;
-    addr = en->call_addr;
+    en = ENCLOSURE_(uslist->us[i].target);
+    if (! NODE_IS_ADDR_FIXED(en)) return ONIGERR_PARSER_BUG;
+    addr = en->m.called_addr;
     offset = uslist->us[i].offset;
 
     BBUF_WRITE(reg, offset, &addr, SIZE_ABSADDR);
@@ -1980,75 +2072,6 @@ unset_addr_list_fix(UnsetAddrList* uslist, regex_t* reg)
 }
 #endif
 
-#ifdef USE_MONOMANIAC_CHECK_CAPTURES_IN_ENDLESS_REPEAT
-static int
-quantifiers_memory_node_info(Node* node)
-{
-  int r = 0;
-
-  switch (NTYPE(node)) {
-  case NT_LIST:
-  case NT_ALT:
-    {
-      int v;
-      do {
-        v = quantifiers_memory_node_info(NCAR(node));
-        if (v > r) r = v;
-      } while (v >= 0 && IS_NOT_NULL(node = NCDR(node)));
-    }
-    break;
-
-#ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    if (IS_CALL_RECURSION(NCALL(node))) {
-      return NQ_TARGET_IS_EMPTY_REC; /* tiny version */
-    }
-    else
-      r = quantifiers_memory_node_info(NCALL(node)->target);
-    break;
-#endif
-
-  case NT_QTFR:
-    {
-      QtfrNode* qn = NQTFR(node);
-      if (qn->upper != 0) {
-        r = quantifiers_memory_node_info(qn->target);
-      }
-    }
-    break;
-
-  case NT_ENCLOSE:
-    {
-      EncloseNode* en = NENCLOSE(node);
-      switch (en->type) {
-      case ENCLOSE_MEMORY:
-        return NQ_TARGET_IS_EMPTY_MEM;
-        break;
-
-      case ENCLOSE_OPTION:
-      case ENCLOSE_STOP_BACKTRACK:
-        r = quantifiers_memory_node_info(en->target);
-        break;
-      default:
-        break;
-      }
-    }
-    break;
-
-  case NT_BREF:
-  case NT_STR:
-  case NT_CTYPE:
-  case NT_CCLASS:
-  case NT_CANY:
-  case NT_ANCHOR:
-  default:
-    break;
-  }
-
-  return r;
-}
-#endif /* USE_MONOMANIAC_CHECK_CAPTURES_IN_ENDLESS_REPEAT */
-
 
 #define GET_CHAR_LEN_VARLEN           -1
 #define GET_CHAR_LEN_TOP_ALT_VARLEN   -2
@@ -2062,23 +2085,23 @@ get_char_length_tree1(Node* node, regex_t* reg, int* len, int level)
 
   level++;
   *len = 0;
-  switch (NTYPE(node)) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     do {
-      r = get_char_length_tree1(NCAR(node), reg, &tlen, level);
+      r = get_char_length_tree1(NODE_CAR(node), reg, &tlen, level);
       if (r == 0)
         *len = distance_add(*len, tlen);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       int tlen2;
       int varlen = 0;
 
-      r = get_char_length_tree1(NCAR(node), reg, &tlen, level);
-      while (r == 0 && IS_NOT_NULL(node = NCDR(node))) {
-        r = get_char_length_tree1(NCAR(node), reg, &tlen2, level);
+      r = get_char_length_tree1(NODE_CAR(node), reg, &tlen, level);
+      while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node))) {
+        r = get_char_length_tree1(NODE_CAR(node), reg, &tlen2, level);
         if (r == 0) {
           if (tlen != tlen2)
             varlen = 1;
@@ -2097,9 +2120,9 @@ get_char_length_tree1(Node* node, regex_t* reg, int* len, int level)
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     {
-      StrNode* sn = NSTR(node);
+      StrNode* sn = STR_(node);
       UChar *s = sn->s;
       while (s < sn->end) {
         s += enclen(reg->enc, s);
@@ -2108,11 +2131,11 @@ get_char_length_tree1(Node* node, regex_t* reg, int* len, int level)
     }
     break;
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
-      QtfrNode* qn = NQTFR(node);
+      QuantNode* qn = QUANT_(node);
       if (qn->lower == qn->upper) {
-        r = get_char_length_tree1(qn->target, reg, &tlen, level);
+        r = get_char_length_tree1(NODE_BODY(node), reg, &tlen, level);
         if (r == 0)
           *len = distance_multiply(tlen, qn->lower);
       }
@@ -2122,43 +2145,42 @@ get_char_length_tree1(Node* node, regex_t* reg, int* len, int level)
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    if (! IS_CALL_RECURSION(NCALL(node)))
-      r = get_char_length_tree1(NCALL(node)->target, reg, len, level);
+  case NODE_CALL:
+    if (! NODE_IS_RECURSION(node))
+      r = get_char_length_tree1(NODE_BODY(node), reg, len, level);
     else
       r = GET_CHAR_LEN_VARLEN;
     break;
 #endif
 
-  case NT_CTYPE:
+  case NODE_CTYPE:
     *len = 1;
     break;
 
-  case NT_CCLASS:
-  case NT_CANY:
+  case NODE_CCLASS:
     *len = 1;
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
       switch (en->type) {
-      case ENCLOSE_MEMORY:
+      case ENCLOSURE_MEMORY:
 #ifdef USE_SUBEXP_CALL
-        if (IS_ENCLOSE_CLEN_FIXED(en))
+        if (NODE_IS_CLEN_FIXED(node))
           *len = en->char_len;
         else {
-          r = get_char_length_tree1(en->target, reg, len, level);
+          r = get_char_length_tree1(NODE_BODY(node), reg, len, level);
           if (r == 0) {
             en->char_len = *len;
-            SET_ENCLOSE_STATUS(node, NST_CLEN_FIXED);
+            NODE_STATUS_ADD(node, NST_CLEN_FIXED);
           }
         }
         break;
 #endif
-      case ENCLOSE_OPTION:
-      case ENCLOSE_STOP_BACKTRACK:
-        r = get_char_length_tree1(en->target, reg, len, level);
+      case ENCLOSURE_OPTION:
+      case ENCLOSURE_STOP_BACKTRACK:
+        r = get_char_length_tree1(NODE_BODY(node), reg, len, level);
         break;
       default:
         break;
@@ -2166,7 +2188,7 @@ get_char_length_tree1(Node* node, regex_t* reg, int* len, int level)
     }
     break;
 
-  case NT_ANCHOR:
+  case NODE_ANCHOR:
     break;
 
   default:
@@ -2185,28 +2207,32 @@ get_char_length_tree(Node* node, regex_t* reg, int* len)
 
 /* x is not included y ==>  1 : 0 */
 static int
-is_not_included(Node* x, Node* y, regex_t* reg)
+is_exclusive(Node* x, Node* y, regex_t* reg)
 {
   int i, len;
   OnigCodePoint code;
   UChar *p;
-  int ytype;
+  NodeType ytype;
 
  retry:
-  ytype = NTYPE(y);
-  switch (NTYPE(x)) {
-  case NT_CTYPE:
+  ytype = NODE_TYPE(y);
+  switch (NODE_TYPE(x)) {
+  case NODE_CTYPE:
     {
+      if (CTYPE_(x)->ctype == CTYPE_ANYCHAR ||
+          CTYPE_(y)->ctype == CTYPE_ANYCHAR)
+        break;
+
       switch (ytype) {
-      case NT_CTYPE:
-        if (NCTYPE(y)->ctype == NCTYPE(x)->ctype &&
-            NCTYPE(y)->not   != NCTYPE(x)->not)
+      case NODE_CTYPE:
+        if (CTYPE_(y)->ctype == CTYPE_(x)->ctype &&
+            CTYPE_(y)->not   != CTYPE_(x)->not)
           return 1;
         else
           return 0;
         break;
 
-      case NT_CCLASS:
+      case NODE_CCLASS:
       swap:
         {
           Node* tmp;
@@ -2215,7 +2241,7 @@ is_not_included(Node* x, Node* y, regex_t* reg)
         }
         break;
 
-      case NT_STR:
+      case NODE_STR:
         goto swap;
         break;
 
@@ -2225,14 +2251,18 @@ is_not_included(Node* x, Node* y, regex_t* reg)
     }
     break;
 
-  case NT_CCLASS:
+  case NODE_CCLASS:
     {
-      CClassNode* xc = NCCLASS(x);
+      CClassNode* xc = CCLASS_(x);
       switch (ytype) {
-      case NT_CTYPE:
-        switch (NCTYPE(y)->ctype) {
+      case NODE_CTYPE:
+        switch (CTYPE_(y)->ctype) {
+        case CTYPE_ANYCHAR:
+          return 0;
+          break;
+
         case ONIGENC_CTYPE_WORD:
-          if (NCTYPE(y)->not == 0) {
+          if (CTYPE_(y)->not == 0) {
             if (IS_NULL(xc->mbuf) && !IS_NCCLASS_NOT(xc)) {
               for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
                 if (BITSET_AT(xc->bs, i)) {
@@ -2266,10 +2296,10 @@ is_not_included(Node* x, Node* y, regex_t* reg)
         }
         break;
 
-      case NT_CCLASS:
+      case NODE_CCLASS:
         {
           int v;
-          CClassNode* yc = NCCLASS(y);
+          CClassNode* yc = CCLASS_(y);
 
           for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
             v = BITSET_AT(xc->bs, i);
@@ -2288,7 +2318,7 @@ is_not_included(Node* x, Node* y, regex_t* reg)
         }
         break;
 
-      case NT_STR:
+      case NODE_STR:
         goto swap;
         break;
 
@@ -2298,30 +2328,33 @@ is_not_included(Node* x, Node* y, regex_t* reg)
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     {
-      StrNode* xs = NSTR(x);
+      StrNode* xs = STR_(x);
       if (NSTRING_LEN(x) == 0)
         break;
 
       //c = *(xs->s);
       switch (ytype) {
-      case NT_CTYPE:
-        switch (NCTYPE(y)->ctype) {
+      case NODE_CTYPE:
+        switch (CTYPE_(y)->ctype) {
+        case CTYPE_ANYCHAR:
+          break;
+
         case ONIGENC_CTYPE_WORD:
           if (ONIGENC_IS_MBC_WORD(reg->enc, xs->s, xs->end))
-            return NCTYPE(y)->not;
+            return CTYPE_(y)->not;
           else
-            return !(NCTYPE(y)->not);
+            return !(CTYPE_(y)->not);
           break;
         default:
           break;
         }
         break;
 
-      case NT_CCLASS:
+      case NODE_CCLASS:
         {
-          CClassNode* cc = NCCLASS(y);
+          CClassNode* cc = CCLASS_(y);
 
           code = ONIGENC_MBC_TO_CODE(reg->enc, xs->s,
                                      xs->s + ONIGENC_MBC_MAXLEN(reg->enc));
@@ -2329,10 +2362,10 @@ is_not_included(Node* x, Node* y, regex_t* reg)
         }
         break;
 
-      case NT_STR:
+      case NODE_STR:
         {
           UChar *q;
-          StrNode* ys = NSTR(y);
+          StrNode* ys = STR_(y);
           len = NSTRING_LEN(x);
           if (len > NSTRING_LEN(y)) len = NSTRING_LEN(y);
           if (NSTRING_IS_AMBIG(x) || NSTRING_IS_AMBIG(y)) {
@@ -2365,29 +2398,31 @@ get_head_value_node(Node* node, int exact, regex_t* reg)
 {
   Node* n = NULL_NODE;
 
-  switch (NTYPE(node)) {
-  case NT_BREF:
-  case NT_ALT:
-  case NT_CANY:
+  switch (NODE_TYPE(node)) {
+  case NODE_BREF:
+  case NODE_ALT:
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
+  case NODE_CALL:
 #endif
     break;
 
-  case NT_CTYPE:
-  case NT_CCLASS:
+  case NODE_CTYPE:
+    if (CTYPE_(node)->ctype == CTYPE_ANYCHAR)
+      break;
+    /* fall */
+  case NODE_CCLASS:
     if (exact == 0) {
       n = node;
     }
     break;
 
-  case NT_LIST:
-    n = get_head_value_node(NCAR(node), exact, reg);
+  case NODE_LIST:
+    n = get_head_value_node(NODE_CAR(node), exact, reg);
     break;
 
-  case NT_STR:
+  case NODE_STR:
     {
-      StrNode* sn = NSTR(node);
+      StrNode* sn = STR_(node);
 
       if (sn->end <= sn->s)
         break;
@@ -2401,43 +2436,43 @@ get_head_value_node(Node* node, int exact, regex_t* reg)
     }
     break;
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
-      QtfrNode* qn = NQTFR(node);
+      QuantNode* qn = QUANT_(node);
       if (qn->lower > 0) {
         if (IS_NOT_NULL(qn->head_exact))
           n = qn->head_exact;
         else
-          n = get_head_value_node(qn->target, exact, reg);
+          n = get_head_value_node(NODE_BODY(node), exact, reg);
       }
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
       switch (en->type) {
-      case ENCLOSE_OPTION:
+      case ENCLOSURE_OPTION:
         {
           OnigOptionType options = reg->options;
 
-          reg->options = NENCLOSE(node)->option;
-          n = get_head_value_node(NENCLOSE(node)->target, exact, reg);
+          reg->options = ENCLOSURE_(node)->o.option;
+          n = get_head_value_node(NODE_BODY(node), exact, reg);
           reg->options = options;
         }
         break;
 
-      case ENCLOSE_MEMORY:
-      case ENCLOSE_STOP_BACKTRACK:
-        n = get_head_value_node(en->target, exact, reg);
+      case ENCLOSURE_MEMORY:
+      case ENCLOSURE_STOP_BACKTRACK:
+        n = get_head_value_node(NODE_BODY(node), exact, reg);
         break;
       }
     }
     break;
 
-  case NT_ANCHOR:
-    if (NANCHOR(node)->type == ANCHOR_PREC_READ)
-      n = get_head_value_node(NANCHOR(node)->target, exact, reg);
+  case NODE_ANCHOR:
+    if (ANCHOR_(node)->type == ANCHOR_PREC_READ)
+      n = get_head_value_node(NODE_BODY(node), exact, reg);
     break;
 
   default:
@@ -2448,46 +2483,45 @@ get_head_value_node(Node* node, int exact, regex_t* reg)
 }
 
 static int
-check_type_tree(Node* node, int type_mask, int enclose_mask, int anchor_mask)
+check_type_tree(Node* node, int type_mask, int enclosure_mask, int anchor_mask)
 {
-  int type, r = 0;
+  NodeType type;
+  int r = 0;
 
-  type = NTYPE(node);
-  if ((NTYPE2BIT(type) & type_mask) == 0)
+  type = NODE_TYPE(node);
+  if ((NODE_TYPE2BIT(type) & type_mask) == 0)
     return 1;
 
   switch (type) {
-  case NT_LIST:
-  case NT_ALT:
+  case NODE_LIST:
+  case NODE_ALT:
     do {
-      r = check_type_tree(NCAR(node), type_mask, enclose_mask,
+      r = check_type_tree(NODE_CAR(node), type_mask, enclosure_mask,
                           anchor_mask);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_QTFR:
-    r = check_type_tree(NQTFR(node)->target, type_mask, enclose_mask,
-                        anchor_mask);
+  case NODE_QUANT:
+    r = check_type_tree(NODE_BODY(node), type_mask, enclosure_mask, anchor_mask);
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
-      if ((en->type & enclose_mask) == 0)
+      EnclosureNode* en = ENCLOSURE_(node);
+      if ((en->type & enclosure_mask) == 0)
         return 1;
 
-      r = check_type_tree(en->target, type_mask, enclose_mask, anchor_mask);
+      r = check_type_tree(NODE_BODY(node), type_mask, enclosure_mask, anchor_mask);
     }
     break;
 
-  case NT_ANCHOR:
-    type = NANCHOR(node)->type;
+  case NODE_ANCHOR:
+    type = ANCHOR_(node)->type;
     if ((type & anchor_mask) == 0)
       return 1;
 
-    if (NANCHOR(node)->target)
-      r = check_type_tree(NANCHOR(node)->target,
-			  type_mask, enclose_mask, anchor_mask);
+    if (IS_NOT_NULL(NODE_BODY(node)))
+      r = check_type_tree(NODE_BODY(node), type_mask, enclosure_mask, anchor_mask);
     break;
 
   default:
@@ -2496,250 +2530,282 @@ check_type_tree(Node* node, int type_mask, int enclose_mask, int anchor_mask)
   return r;
 }
 
-static int
-get_min_len(Node* node, OnigLen *min, ScanEnv* env)
+static OnigLen
+get_min_len(Node* node, ScanEnv* env)
 {
+  OnigLen len;
   OnigLen tmin;
-  int r = 0;
 
-  *min = 0;
-  switch (NTYPE(node)) {
-  case NT_BREF:
+  len = 0;
+  switch (NODE_TYPE(node)) {
+  case NODE_BREF:
     {
       int i;
       int* backs;
-      Node** nodes = SCANENV_MEM_NODES(env);
-      BRefNode* br = NBREF(node);
-      if (br->state & NST_RECURSION) break;
+      MemEnv* mem_env = SCANENV_MEMENV(env);
+      BRefNode* br = BREF_(node);
+      if (NODE_IS_RECURSION(node)) break;
 
       backs = BACKREFS_P(br);
-      if (backs[0] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
-      r = get_min_len(nodes[backs[0]], min, env);
-      if (r != 0) break;
+      len = get_min_len(mem_env[backs[0]].node, env);
       for (i = 1; i < br->back_num; i++) {
-        if (backs[i] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
-        r = get_min_len(nodes[backs[i]], &tmin, env);
-        if (r != 0) break;
-        if (*min > tmin) *min = tmin;
+        tmin = get_min_len(mem_env[backs[i]].node, env);
+        if (len > tmin) len = tmin;
       }
     }
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    if (IS_CALL_RECURSION(NCALL(node))) {
-      EncloseNode* en = NENCLOSE(NCALL(node)->target);
-      if (IS_ENCLOSE_MIN_FIXED(en))
-        *min = en->min_len;
+  case NODE_CALL:
+    {
+      Node* t = NODE_BODY(node);
+      if (NODE_IS_RECURSION(node)) {
+        if (NODE_IS_MIN_FIXED(t))
+          len = ENCLOSURE_(t)->min_len;
+      }
+      else
+        len = get_min_len(t, env);
     }
-    else
-      r = get_min_len(NCALL(node)->target, min, env);
     break;
 #endif
 
-  case NT_LIST:
+  case NODE_LIST:
     do {
-      r = get_min_len(NCAR(node), &tmin, env);
-      if (r == 0) *min += tmin;
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      tmin = get_min_len(NODE_CAR(node), env);
+      len += tmin;
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       Node *x, *y;
       y = node;
       do {
-        x = NCAR(y);
-        r = get_min_len(x, &tmin, env);
-        if (r != 0) break;
-        if (y == node) *min = tmin;
-        else if (*min > tmin) *min = tmin;
-      } while (r == 0 && IS_NOT_NULL(y = NCDR(y)));
+        x = NODE_CAR(y);
+        tmin = get_min_len(x, env);
+        if (y == node) len = tmin;
+        else if (len > tmin) len = tmin;
+      } while (IS_NOT_NULL(y = NODE_CDR(y)));
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     {
-      StrNode* sn = NSTR(node);
-      *min = sn->end - sn->s;
+      StrNode* sn = STR_(node);
+      len = sn->end - sn->s;
     }
     break;
 
-  case NT_CTYPE:
-    *min = 1;
+  case NODE_CTYPE:
+  case NODE_CCLASS:
+    len = 1;
     break;
 
-  case NT_CCLASS:
-  case NT_CANY:
-    *min = 1;
-    break;
-
-  case NT_QTFR:
+  case NODE_QUANT:
     {
-      QtfrNode* qn = NQTFR(node);
+      QuantNode* qn = QUANT_(node);
 
       if (qn->lower > 0) {
-        r = get_min_len(qn->target, min, env);
-        if (r == 0)
-          *min = distance_multiply(*min, qn->lower);
+        len = get_min_len(NODE_BODY(node), env);
+        len = distance_multiply(len, qn->lower);
       }
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
       switch (en->type) {
-      case ENCLOSE_MEMORY:
-        if (IS_ENCLOSE_MIN_FIXED(en))
-          *min = en->min_len;
+      case ENCLOSURE_MEMORY:
+        if (NODE_IS_MIN_FIXED(node))
+          len = en->min_len;
         else {
-          if (IS_ENCLOSE_MARK1(NENCLOSE(node)))
-            *min = 0;  // recursive
+          if (NODE_IS_MARK1(node))
+            len = 0;  // recursive
           else {
-            SET_ENCLOSE_STATUS(node, NST_MARK1);
-            r = get_min_len(en->target, min, env);
-            CLEAR_ENCLOSE_STATUS(node, NST_MARK1);
-            if (r == 0) {
-              en->min_len = *min;
-              SET_ENCLOSE_STATUS(node, NST_MIN_FIXED);
-            }
+            NODE_STATUS_ADD(node, NST_MARK1);
+            len = get_min_len(NODE_BODY(node), env);
+            NODE_STATUS_REMOVE(node, NST_MARK1);
+
+            en->min_len = len;
+            NODE_STATUS_ADD(node, NST_MIN_FIXED);
           }
         }
         break;
 
-      case ENCLOSE_OPTION:
-      case ENCLOSE_STOP_BACKTRACK:
-        r = get_min_len(en->target, min, env);
+      case ENCLOSURE_OPTION:
+      case ENCLOSURE_STOP_BACKTRACK:
+        len = get_min_len(NODE_BODY(node), env);
         break;
       }
     }
     break;
 
-  case NT_ANCHOR:
+  case NODE_ANCHOR:
   default:
     break;
   }
 
-  return r;
+  return len;
 }
 
-static int
-get_max_len(Node* node, OnigLen *max, ScanEnv* env)
+static OnigLen
+get_max_len(Node* node, ScanEnv* env)
 {
+  OnigLen len;
   OnigLen tmax;
-  int r = 0;
 
-  *max = 0;
-  switch (NTYPE(node)) {
-  case NT_LIST:
+  len = 0;
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     do {
-      r = get_max_len(NCAR(node), &tmax, env);
-      if (r == 0)
-        *max = distance_add(*max, tmax);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      tmax = get_max_len(NODE_CAR(node), env);
+      len = distance_add(len, tmax);
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     do {
-      r = get_max_len(NCAR(node), &tmax, env);
-      if (r == 0 && *max < tmax) *max = tmax;
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      tmax = get_max_len(NODE_CAR(node), env);
+      if (len < tmax) len = tmax;
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_STR:
+  case NODE_STR:
     {
-      StrNode* sn = NSTR(node);
-      *max = sn->end - sn->s;
+      StrNode* sn = STR_(node);
+      len = sn->end - sn->s;
     }
     break;
 
-  case NT_CTYPE:
-    *max = ONIGENC_MBC_MAXLEN_DIST(env->enc);
+  case NODE_CTYPE:
+  case NODE_CCLASS:
+    len = ONIGENC_MBC_MAXLEN_DIST(env->enc);
     break;
 
-  case NT_CCLASS:
-  case NT_CANY:
-    *max = ONIGENC_MBC_MAXLEN_DIST(env->enc);
-    break;
-
-  case NT_BREF:
+  case NODE_BREF:
     {
       int i;
       int* backs;
-      Node** nodes = SCANENV_MEM_NODES(env);
-      BRefNode* br = NBREF(node);
-      if (br->state & NST_RECURSION) {
-        *max = ONIG_INFINITE_DISTANCE;
+      MemEnv* mem_env = SCANENV_MEMENV(env);
+      BRefNode* br = BREF_(node);
+      if (NODE_IS_RECURSION(node)) {
+        len = ONIG_INFINITE_DISTANCE;
         break;
       }
       backs = BACKREFS_P(br);
       for (i = 0; i < br->back_num; i++) {
-        if (backs[i] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
-        r = get_max_len(nodes[backs[i]], &tmax, env);
-        if (r != 0) break;
-        if (*max < tmax) *max = tmax;
+        tmax = get_max_len(mem_env[backs[i]].node, env);
+        if (len < tmax) len = tmax;
       }
     }
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    if (! IS_CALL_RECURSION(NCALL(node)))
-      r = get_max_len(NCALL(node)->target, max, env);
+  case NODE_CALL:
+    if (! NODE_IS_RECURSION(node))
+      len = get_max_len(NODE_BODY(node), env);
     else
-      *max = ONIG_INFINITE_DISTANCE;
+      len = ONIG_INFINITE_DISTANCE;
     break;
 #endif
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
-      QtfrNode* qn = NQTFR(node);
+      QuantNode* qn = QUANT_(node);
 
       if (qn->upper != 0) {
-        r = get_max_len(qn->target, max, env);
-        if (r == 0 && *max != 0) {
+        len = get_max_len(NODE_BODY(node), env);
+        if (len != 0) {
           if (! IS_REPEAT_INFINITE(qn->upper))
-            *max = distance_multiply(*max, qn->upper);
+            len = distance_multiply(len, qn->upper);
           else
-            *max = ONIG_INFINITE_DISTANCE;
+            len = ONIG_INFINITE_DISTANCE;
         }
       }
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
       switch (en->type) {
-      case ENCLOSE_MEMORY:
-        if (IS_ENCLOSE_MAX_FIXED(en))
-          *max = en->max_len;
+      case ENCLOSURE_MEMORY:
+        if (NODE_IS_MAX_FIXED(node))
+          len = en->max_len;
         else {
-          if (IS_ENCLOSE_MARK1(NENCLOSE(node)))
-            *max = ONIG_INFINITE_DISTANCE;
+          if (NODE_IS_MARK1(node))
+            len = ONIG_INFINITE_DISTANCE;
           else {
-            SET_ENCLOSE_STATUS(node, NST_MARK1);
-            r = get_max_len(en->target, max, env);
-            CLEAR_ENCLOSE_STATUS(node, NST_MARK1);
-            if (r == 0) {
-              en->max_len = *max;
-              SET_ENCLOSE_STATUS(node, NST_MAX_FIXED);
-            }
+            NODE_STATUS_ADD(node, NST_MARK1);
+            len = get_max_len(NODE_BODY(node), env);
+            NODE_STATUS_REMOVE(node, NST_MARK1);
+
+            en->max_len = len;
+            NODE_STATUS_ADD(node, NST_MAX_FIXED);
           }
         }
         break;
 
-      case ENCLOSE_OPTION:
-      case ENCLOSE_STOP_BACKTRACK:
-        r = get_max_len(en->target, max, env);
+      case ENCLOSURE_OPTION:
+      case ENCLOSURE_STOP_BACKTRACK:
+        len = get_max_len(NODE_BODY(node), env);
         break;
       }
     }
     break;
 
-  case NT_ANCHOR:
+  case NODE_ANCHOR:
+  default:
+    break;
+  }
+
+  return len;
+}
+
+static int
+check_backrefs(Node* node, ScanEnv* env)
+{
+  int r;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      r = check_backrefs(NODE_CAR(node), env);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_ANCHOR:
+    if (! ANCHOR_HAS_BODY(ANCHOR_(node))) {
+      r = 0;
+      break;
+    }
+    /* fall */
+  case NODE_QUANT:
+  case NODE_ENCLOSURE:
+    r = check_backrefs(NODE_BODY(node), env);
+    break;
+
+  case NODE_BREF:
+    {
+      int i;
+      BRefNode* br = BREF_(node);
+      int* backs = BACKREFS_P(br);
+      MemEnv* mem_env = SCANENV_MEMENV(env);
+
+      for (i = 0; i < br->back_num; i++) {
+        if (backs[i] > env->num_mem)
+          return ONIGERR_INVALID_BACKREF;
+
+        NODE_STATUS_ADD(mem_env[backs[i]].node, NST_BACKREF);
+      }
+      r = 0;
+    }
+    break;
+
   default:
+    r = 0;
     break;
   }
 
@@ -2749,18 +2815,17 @@ get_max_len(Node* node, OnigLen *max, ScanEnv* env)
 
 #ifdef USE_SUBEXP_CALL
 
-#define RECURSION_EXIST       1
-#define RECURSION_INFINITE    2
+#define RECURSION_EXIST        (1<<0)
+#define RECURSION_MUST         (1<<1)
+#define RECURSION_INFINITE     (1<<2)
 
 static int
-subexp_inf_recursive_check(Node* node, ScanEnv* env, int head)
+infinite_recursive_call_check(Node* node, ScanEnv* env, int head)
 {
-  int type;
   int r = 0;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     {
       Node *x;
       OnigLen min;
@@ -2768,64 +2833,70 @@ subexp_inf_recursive_check(Node* node, ScanEnv* env, int head)
 
       x = node;
       do {
-        ret = subexp_inf_recursive_check(NCAR(x), env, head);
-        if (ret < 0 || ret == RECURSION_INFINITE) return ret;
+        ret = infinite_recursive_call_check(NODE_CAR(x), env, head);
+        if (ret < 0 || (ret & RECURSION_INFINITE) != 0) return ret;
         r |= ret;
         if (head) {
-          ret = get_min_len(NCAR(x), &min, env);
-          if (ret != 0) return ret;
+          min = get_min_len(NODE_CAR(x), env);
           if (min != 0) head = 0;
         }
-      } while (IS_NOT_NULL(x = NCDR(x)));
+      } while (IS_NOT_NULL(x = NODE_CDR(x)));
     }
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       int ret;
-      r = RECURSION_EXIST;
+      int must;
+
+      must = RECURSION_MUST;
       do {
-        ret = subexp_inf_recursive_check(NCAR(node), env, head);
-        if (ret < 0 || ret == RECURSION_INFINITE) return ret;
-        r &= ret;
-      } while (IS_NOT_NULL(node = NCDR(node)));
-    }
-    break;
+        ret = infinite_recursive_call_check(NODE_CAR(node), env, head);
+        if (ret < 0 || (ret & RECURSION_INFINITE) != 0) return ret;
 
-  case NT_QTFR:
-    r = subexp_inf_recursive_check(NQTFR(node)->target, env, head);
-    if (r == RECURSION_EXIST) {
-      if (NQTFR(node)->lower == 0) r = 0;
+        r    |= (ret & RECURSION_EXIST);
+        must &= ret;
+      } while (IS_NOT_NULL(node = NODE_CDR(node)));
+      r |= must;
     }
     break;
 
-  case NT_ANCHOR:
-    {
-      AnchorNode* an = NANCHOR(node);
-      switch (an->type) {
-      case ANCHOR_PREC_READ:
-      case ANCHOR_PREC_READ_NOT:
-      case ANCHOR_LOOK_BEHIND:
-      case ANCHOR_LOOK_BEHIND_NOT:
-        r = subexp_inf_recursive_check(an->target, env, head);
-        break;
-      }
+  case NODE_QUANT:
+    r = infinite_recursive_call_check(NODE_BODY(node), env, head);
+    if (r < 0) return r;
+    if ((r & RECURSION_MUST) != 0) {
+      if (QUANT_(node)->lower == 0)
+        r &= ~RECURSION_MUST;
     }
     break;
 
-  case NT_CALL:
-    r = subexp_inf_recursive_check(NCALL(node)->target, env, head);
+  case NODE_ANCHOR:
+    if (! ANCHOR_HAS_BODY(ANCHOR_(node)))
+      break;
+    /* fall */
+  case NODE_CALL:
+    r = infinite_recursive_call_check(NODE_BODY(node), env, head);
     break;
 
-  case NT_ENCLOSE:
-    if (IS_ENCLOSE_MARK2(NENCLOSE(node)))
-      return 0;
-    else if (IS_ENCLOSE_MARK1(NENCLOSE(node)))
-      return (head == 0 ? RECURSION_EXIST : RECURSION_INFINITE);
-    else {
-      SET_ENCLOSE_STATUS(node, NST_MARK2);
-      r = subexp_inf_recursive_check(NENCLOSE(node)->target, env, head);
-      CLEAR_ENCLOSE_STATUS(node, NST_MARK2);
+  case NODE_ENCLOSURE:
+    {
+      EnclosureNode* en = ENCLOSURE_(node);
+
+      if (en->type == ENCLOSURE_MEMORY) {
+        if (NODE_IS_MARK2(node))
+          return 0;
+        else if (NODE_IS_MARK1(node))
+          return (head == 0 ? RECURSION_EXIST | RECURSION_MUST
+                  : RECURSION_EXIST | RECURSION_MUST | RECURSION_INFINITE);
+        else {
+          NODE_STATUS_ADD(node, NST_MARK2);
+          r = infinite_recursive_call_check(NODE_BODY(node), env, head);
+          NODE_STATUS_REMOVE(node, NST_MARK2);
+        }
+      }
+      else {
+        r = infinite_recursive_call_check(NODE_BODY(node), env, head);
+      }
     }
     break;
 
@@ -2837,53 +2908,53 @@ subexp_inf_recursive_check(Node* node, ScanEnv* env, int head)
 }
 
 static int
-subexp_inf_recursive_check_trav(Node* node, ScanEnv* env)
+infinite_recursive_call_check_trav(Node* node, ScanEnv* env)
 {
-  int type;
-  int r = 0;
+  int r;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
-  case NT_ALT:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     do {
-      r = subexp_inf_recursive_check_trav(NCAR(node), env);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      r = infinite_recursive_call_check_trav(NODE_CAR(node), env);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_QTFR:
-    r = subexp_inf_recursive_check_trav(NQTFR(node)->target, env);
-    break;
-
-  case NT_ANCHOR:
-    {
-      AnchorNode* an = NANCHOR(node);
-      switch (an->type) {
-      case ANCHOR_PREC_READ:
-      case ANCHOR_PREC_READ_NOT:
-      case ANCHOR_LOOK_BEHIND:
-      case ANCHOR_LOOK_BEHIND_NOT:
-        r = subexp_inf_recursive_check_trav(an->target, env);
-        break;
-      }
+  case NODE_ANCHOR:
+    if (! ANCHOR_HAS_BODY(ANCHOR_(node))) {
+      r = 0;
+      break;
     }
+    /* fall */
+  case NODE_QUANT:
+    r = infinite_recursive_call_check_trav(NODE_BODY(node), env);
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
+
+      if (en->type == ENCLOSURE_MEMORY) {
+        if (NODE_IS_RECURSION(node) && NODE_IS_CALLED(node)) {
+          int ret;
+
+          NODE_STATUS_ADD(node, NST_MARK1);
 
-      if (IS_ENCLOSE_RECURSION(en)) {
-        SET_ENCLOSE_STATUS(node, NST_MARK1);
-        r = subexp_inf_recursive_check(en->target, env, 1);
-        if (r > 0) return ONIGERR_NEVER_ENDING_RECURSION;
-        CLEAR_ENCLOSE_STATUS(node, NST_MARK1);
+          ret = infinite_recursive_call_check(NODE_BODY(node), env, 1);
+          if (ret < 0) return ret;
+          else if ((ret & (RECURSION_MUST | RECURSION_INFINITE)) != 0)
+            return ONIGERR_NEVER_ENDING_RECURSION;
+
+          NODE_STATUS_REMOVE(node, NST_MARK1);
+        }
       }
-      r = subexp_inf_recursive_check_trav(en->target, env);
     }
+
+    r = infinite_recursive_call_check_trav(NODE_BODY(node), env);
     break;
 
   default:
+    r = 0;
     break;
   }
 
@@ -2891,227 +2962,129 @@ subexp_inf_recursive_check_trav(Node* node, ScanEnv* env)
 }
 
 static int
-subexp_recursive_check(Node* node)
+recursive_call_check(Node* node)
 {
-  int r = 0;
+  int r;
 
-  switch (NTYPE(node)) {
-  case NT_LIST:
-  case NT_ALT:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    r = 0;
     do {
-      r |= subexp_recursive_check(NCAR(node));
-    } while (IS_NOT_NULL(node = NCDR(node)));
+      r |= recursive_call_check(NODE_CAR(node));
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_QTFR:
-    r = subexp_recursive_check(NQTFR(node)->target);
-    break;
-
-  case NT_ANCHOR:
-    {
-      AnchorNode* an = NANCHOR(node);
-      switch (an->type) {
-      case ANCHOR_PREC_READ:
-      case ANCHOR_PREC_READ_NOT:
-      case ANCHOR_LOOK_BEHIND:
-      case ANCHOR_LOOK_BEHIND_NOT:
-        r = subexp_recursive_check(an->target);
-        break;
-      }
+  case NODE_ANCHOR:
+    if (! ANCHOR_HAS_BODY(ANCHOR_(node))) {
+      r = 0;
+      break;
     }
+    /* fall */
+  case NODE_QUANT:
+    r = recursive_call_check(NODE_BODY(node));
     break;
 
-  case NT_CALL:
-    r = subexp_recursive_check(NCALL(node)->target);
-    if (r != 0) SET_CALL_RECURSION(node);
+  case NODE_CALL:
+    r = recursive_call_check(NODE_BODY(node));
+    if (r != 0) NODE_STATUS_ADD(node, NST_RECURSION);
     break;
 
-  case NT_ENCLOSE:
-    if (IS_ENCLOSE_MARK2(NENCLOSE(node)))
-      return 0;
-    else if (IS_ENCLOSE_MARK1(NENCLOSE(node)))
-      return 1; /* recursion */
-    else {
-      SET_ENCLOSE_STATUS(node, NST_MARK2);
-      r = subexp_recursive_check(NENCLOSE(node)->target);
-      CLEAR_ENCLOSE_STATUS(node, NST_MARK2);
+  case NODE_ENCLOSURE:
+    {
+      EnclosureNode* en = ENCLOSURE_(node);
+
+      if (en->type == ENCLOSURE_MEMORY) {
+        if (NODE_IS_MARK2(node))
+          return 0;
+        else if (NODE_IS_MARK1(node))
+          return 1; /* recursion */
+        else {
+          NODE_STATUS_ADD(node, NST_MARK2);
+          r = recursive_call_check(NODE_BODY(node));
+          NODE_STATUS_REMOVE(node, NST_MARK2);
+        }
+      }
+      else {
+        r = recursive_call_check(NODE_BODY(node));
+      }
     }
     break;
 
   default:
+    r = 0;
     break;
   }
 
   return r;
 }
 
+#define IN_RECURSION         (1<<0)
+#define FOUND_CALLED_NODE    1
 
 static int
-subexp_recursive_check_trav(Node* node, ScanEnv* env)
+recursive_call_check_trav(Node* node, ScanEnv* env, int state)
 {
-#define FOUND_CALLED_NODE    1
-
-  int type;
   int r = 0;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
-  case NT_ALT:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     {
       int ret;
       do {
-        ret = subexp_recursive_check_trav(NCAR(node), env);
+        ret = recursive_call_check_trav(NODE_CAR(node), env, state);
         if (ret == FOUND_CALLED_NODE) r = FOUND_CALLED_NODE;
         else if (ret < 0) return ret;
-      } while (IS_NOT_NULL(node = NCDR(node)));
+      } while (IS_NOT_NULL(node = NODE_CDR(node)));
     }
     break;
 
-  case NT_QTFR:
-    r = subexp_recursive_check_trav(NQTFR(node)->target, env);
-    if (NQTFR(node)->upper == 0) {
+  case NODE_QUANT:
+    r = recursive_call_check_trav(NODE_BODY(node), env, state);
+    if (QUANT_(node)->upper == 0) {
       if (r == FOUND_CALLED_NODE)
-        NQTFR(node)->is_refered = 1;
+        QUANT_(node)->is_refered = 1;
     }
     break;
 
-  case NT_ANCHOR:
+  case NODE_ANCHOR:
     {
-      AnchorNode* an = NANCHOR(node);
-      switch (an->type) {
-      case ANCHOR_PREC_READ:
-      case ANCHOR_PREC_READ_NOT:
-      case ANCHOR_LOOK_BEHIND:
-      case ANCHOR_LOOK_BEHIND_NOT:
-        r = subexp_recursive_check_trav(an->target, env);
-        break;
-      }
+      AnchorNode* an = ANCHOR_(node);
+      if (ANCHOR_HAS_BODY(an))
+        r = recursive_call_check_trav(NODE_ANCHOR_BODY(an), env, state);
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
-
-      if (! IS_ENCLOSE_RECURSION(en)) {
-        if (IS_ENCLOSE_CALLED(en)) {
-          SET_ENCLOSE_STATUS(node, NST_MARK1);
-          r = subexp_recursive_check(en->target);
-          if (r != 0) SET_ENCLOSE_STATUS(node, NST_RECURSION);
-          CLEAR_ENCLOSE_STATUS(node, NST_MARK1);
-        }
-      }
-      r = subexp_recursive_check_trav(en->target, env);
-      if (IS_ENCLOSE_CALLED(en))
-        r |= FOUND_CALLED_NODE;
-    }
-    break;
-
-  default:
-    break;
-  }
-
-  return r;
-}
-
-static int
-setup_subexp_call(Node* node, ScanEnv* env)
-{
-  int type;
-  int r = 0;
-
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
-    do {
-      r = setup_subexp_call(NCAR(node), env);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
-    break;
-
-  case NT_ALT:
-    do {
-      r = setup_subexp_call(NCAR(node), env);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
-    break;
-
-  case NT_QTFR:
-    r = setup_subexp_call(NQTFR(node)->target, env);
-    break;
-  case NT_ENCLOSE:
-    r = setup_subexp_call(NENCLOSE(node)->target, env);
-    break;
-
-  case NT_CALL:
-    {
-      CallNode* cn = NCALL(node);
-      Node** nodes = SCANENV_MEM_NODES(env);
-
-      if (cn->group_num != 0) {
-        int gnum = cn->group_num;
-
-#ifdef USE_NAMED_GROUP
-        if (env->num_named > 0 &&
-            IS_SYNTAX_BV(env->syntax, ONIG_SYN_CAPTURE_ONLY_NAMED_GROUP) &&
-            !ONIG_IS_OPTION_ON(env->option, ONIG_OPTION_CAPTURE_GROUP)) {
-          return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;
-        }
-#endif
-        if (gnum > env->num_mem) {
-          onig_scan_env_set_error_string(env,
-                   ONIGERR_UNDEFINED_GROUP_REFERENCE, cn->name, cn->name_end);
-          return ONIGERR_UNDEFINED_GROUP_REFERENCE;
-        }
+      EnclosureNode* en = ENCLOSURE_(node);
+
+      if (en->type == ENCLOSURE_MEMORY) {
+        if (NODE_IS_CALLED(node) || (state & IN_RECURSION) != 0) {
+          if (! NODE_IS_RECURSION(node)) {
+            NODE_STATUS_ADD(node, NST_MARK1);
+            r = recursive_call_check(NODE_BODY(node));
+            if (r != 0)
+              NODE_STATUS_ADD(node, NST_RECURSION);
+            NODE_STATUS_REMOVE(node, NST_MARK1);
+          }
 
-#ifdef USE_NAMED_GROUP
-      set_call_attr:
-#endif
-        cn->target = nodes[cn->group_num];
-        if (IS_NULL(cn->target)) {
-          onig_scan_env_set_error_string(env,
-                   ONIGERR_UNDEFINED_NAME_REFERENCE, cn->name, cn->name_end);
-          return ONIGERR_UNDEFINED_NAME_REFERENCE;
-        }
-        SET_ENCLOSE_STATUS(cn->target, NST_CALLED);
-        BIT_STATUS_ON_AT(env->bt_mem_start, cn->group_num);
-        cn->unset_addr_list = env->unset_addr_list;
-      }
-#ifdef USE_NAMED_GROUP
-      else {
-        int *refs;
-
-        int n = onig_name_to_group_numbers(env->reg, cn->name, cn->name_end,
-                                           &refs);
-        if (n <= 0) {
-          onig_scan_env_set_error_string(env,
-                   ONIGERR_UNDEFINED_NAME_REFERENCE, cn->name, cn->name_end);
-          return ONIGERR_UNDEFINED_NAME_REFERENCE;
-        }
-        else if (n > 1) {
-          onig_scan_env_set_error_string(env,
-               ONIGERR_MULTIPLEX_DEFINITION_NAME_CALL, cn->name, cn->name_end);
-          return ONIGERR_MULTIPLEX_DEFINITION_NAME_CALL;
-        }
-        else {
-          cn->group_num = refs[0];
-          goto set_call_attr;
+          if (NODE_IS_CALLED(node))
+            r = FOUND_CALLED_NODE;
         }
       }
-#endif
-    }
-    break;
 
-  case NT_ANCHOR:
-    {
-      AnchorNode* an = NANCHOR(node);
+      {
+        int ret;
+        int state1 = state;
 
-      switch (an->type) {
-      case ANCHOR_PREC_READ:
-      case ANCHOR_PREC_READ_NOT:
-      case ANCHOR_LOOK_BEHIND:
-      case ANCHOR_LOOK_BEHIND_NOT:
-        r = setup_subexp_call(an->target, env);
-        break;
+        if (NODE_IS_RECURSION(node))
+          state1 |= IN_RECURSION;
+
+        ret = recursive_call_check_trav(NODE_BODY(node), env, state1);
+        if (ret == FOUND_CALLED_NODE)
+          r = FOUND_CALLED_NODE;
       }
     }
     break;
@@ -3122,6 +3095,7 @@ setup_subexp_call(Node* node, ScanEnv* env)
 
   return r;
 }
+
 #endif
 
 /* divide different length alternatives in look-behind.
@@ -3132,30 +3106,28 @@ static int
 divide_look_behind_alternatives(Node* node)
 {
   Node *head, *np, *insert_node;
-  AnchorNode* an = NANCHOR(node);
+  AnchorNode* an = ANCHOR_(node);
   int anc_type = an->type;
 
-  /* fprintf(stderr, "divide_look_behind: %d\n", (int )node); */
-
-  head = an->target;
-  np = NCAR(head);
+  head = NODE_ANCHOR_BODY(an);
+  np = NODE_CAR(head);
   swap_node(node, head);
-  NCAR(node) = head;
-  NANCHOR(head)->target = np;
+  NODE_CAR(node) = head;
+  NODE_BODY(head) = np;
 
   np = node;
-  while ((np = NCDR(np)) != NULL_NODE) {
+  while (IS_NOT_NULL(np = NODE_CDR(np))) {
     insert_node = onig_node_new_anchor(anc_type);
     CHECK_NULL_RETURN_MEMERR(insert_node);
-    NANCHOR(insert_node)->target = NCAR(np);
-    NCAR(np) = insert_node;
+    NODE_BODY(insert_node) = NODE_CAR(np);
+    NODE_CAR(np) = insert_node;
   }
 
   if (anc_type == ANCHOR_LOOK_BEHIND_NOT) {
     np = node;
     do {
-      SET_NTYPE(np, NT_LIST);  /* alt -> list */
-    } while ((np = NCDR(np)) != NULL_NODE);
+      SET_NODE_TYPE(np, NODE_LIST);  /* alt -> list */
+    } while (IS_NOT_NULL(np = NODE_CDR(np)));
   }
   return 0;
 }
@@ -3164,11 +3136,9 @@ static int
 setup_look_behind(Node* node, regex_t* reg, ScanEnv* env)
 {
   int r, len;
-  AnchorNode* an = NANCHOR(node);
-
-  /* fprintf(stderr, "setup_look_behind: %x\n", (int )node); */
+  AnchorNode* an = ANCHOR_(node);
 
-  r = get_char_length_tree(an->target, reg, &len);
+  r = get_char_length_tree(NODE_ANCHOR_BODY(an), reg, &len);
   if (r == 0)
     an->char_len = len;
   else if (r == GET_CHAR_LEN_VARLEN)
@@ -3186,44 +3156,43 @@ setup_look_behind(Node* node, regex_t* reg, ScanEnv* env)
 static int
 next_setup(Node* node, Node* next_node, regex_t* reg)
 {
-  int type;
+  NodeType type;
 
  retry:
-  type = NTYPE(node);
-  if (type == NT_QTFR) {
-    QtfrNode* qn = NQTFR(node);
+  type = NODE_TYPE(node);
+  if (type == NODE_QUANT) {
+    QuantNode* qn = QUANT_(node);
     if (qn->greedy && IS_REPEAT_INFINITE(qn->upper)) {
-#ifdef USE_QTFR_PEEK_NEXT
+#ifdef USE_QUANT_PEEK_NEXT
       Node* n = get_head_value_node(next_node, 1, reg);
       /* '\0': for UTF-16BE etc... */
-      if (IS_NOT_NULL(n) && NSTR(n)->s[0] != '\0') {
+      if (IS_NOT_NULL(n) && STR_(n)->s[0] != '\0') {
         qn->next_head_exact = n;
       }
 #endif
       /* automatic posseivation a*b ==> (?>a*)b */
       if (qn->lower <= 1) {
-        int ttype = NTYPE(qn->target);
-        if (IS_NODE_TYPE_SIMPLE(ttype)) {
+        if (NODE_IS_SIMPLE_TYPE(NODE_BODY(node))) {
           Node *x, *y;
-          x = get_head_value_node(qn->target, 0, reg);
+          x = get_head_value_node(NODE_BODY(node), 0, reg);
           if (IS_NOT_NULL(x)) {
             y = get_head_value_node(next_node,  0, reg);
-            if (IS_NOT_NULL(y) && is_not_included(x, y, reg)) {
-              Node* en = onig_node_new_enclose(ENCLOSE_STOP_BACKTRACK);
+            if (IS_NOT_NULL(y) && is_exclusive(x, y, reg)) {
+              Node* en = onig_node_new_enclosure(ENCLOSURE_STOP_BACKTRACK);
               CHECK_NULL_RETURN_MEMERR(en);
-              SET_ENCLOSE_STATUS(en, NST_STOP_BT_SIMPLE_REPEAT);
+              NODE_STATUS_ADD(en, NST_STOP_BT_SIMPLE_REPEAT);
               swap_node(node, en);
-              NENCLOSE(node)->target = en;
+              NODE_BODY(node) = en;
             }
           }
         }
       }
     }
   }
-  else if (type == NT_ENCLOSE) {
-    EncloseNode* en = NENCLOSE(node);
-    if (en->type == ENCLOSE_MEMORY) {
-      node = en->target;
+  else if (type == NODE_ENCLOSURE) {
+    EnclosureNode* en = ENCLOSURE_(node);
+    if (en->type == ENCLOSURE_MEMORY) {
+      node = NODE_BODY(node);
       goto retry;
     }
   }
@@ -3237,7 +3206,7 @@ update_string_node_case_fold(regex_t* reg, Node *node)
   UChar *p, *end, buf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
   UChar *sbuf, *ebuf, *sp;
   int r, i, len, sbuf_size;
-  StrNode* sn = NSTR(node);
+  StrNode* sn = STR_(node);
 
   end = sn->end;
   sbuf_size = (end - sn->s) * 2;
@@ -3319,11 +3288,11 @@ expand_case_fold_string_alt(int item_num, OnigCaseFoldCodeItem items[],
 
     xnode = onig_node_new_list(NULL, NULL);
     if (IS_NULL(xnode)) goto mem_err;
-    NCAR(var_anode) = xnode;
+    NODE_CAR(var_anode) = xnode;
 
     anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
     if (IS_NULL(anode)) goto mem_err;
-    NCAR(xnode) = anode;
+    NODE_CAR(xnode) = anode;
   }
   else {
     *rnode = anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
@@ -3333,7 +3302,7 @@ expand_case_fold_string_alt(int item_num, OnigCaseFoldCodeItem items[],
   snode = onig_node_new_str(p, p + slen);
   if (IS_NULL(snode)) goto mem_err;
 
-  NCAR(anode) = snode;
+  NODE_CAR(anode) = snode;
 
   for (i = 0; i < item_num; i++) {
     snode = onig_node_new_str(NULL, NULL);
@@ -3379,18 +3348,18 @@ expand_case_fold_string_alt(int item_num, OnigCaseFoldCodeItem items[],
           goto mem_err;
         }
 
-        NCAR(an) = xnode;
+        NODE_CAR(an) = xnode;
       }
       else {
-        NCAR(an) = snode;
+        NODE_CAR(an) = snode;
       }
 
-      NCDR(var_anode) = an;
+      NODE_CDR(var_anode) = an;
       var_anode = an;
     }
     else {
-      NCAR(an)     = snode;
-      NCDR(anode) = an;
+      NODE_CAR(an)     = snode;
+      NODE_CDR(anode) = an;
       anode = an;
     }
   }
@@ -3415,7 +3384,7 @@ expand_case_fold_string(Node* node, regex_t* reg)
   UChar *start, *end, *p;
   Node *top_root, *root, *snode, *prev_node;
   OnigCaseFoldCodeItem items[ONIGENC_GET_CASE_FOLD_CODES_MAX_NUM];
-  StrNode* sn = NSTR(node);
+  StrNode* sn = STR_(node);
 
   if (NSTRING_IS_AMBIG(node)) return 0;
 
@@ -3485,7 +3454,7 @@ expand_case_fold_string(Node* node, regex_t* reg)
           }
         }
 
-        root = NCAR(prev_node);
+        root = NODE_CAR(prev_node);
       }
       else { /* r == 0 */
         if (IS_NOT_NULL(root)) {
@@ -3555,37 +3524,35 @@ expand_case_fold_string(Node* node, regex_t* reg)
 static int
 setup_comb_exp_check(Node* node, int state, ScanEnv* env)
 {
-  int type;
   int r = state;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     {
       Node* prev = NULL_NODE;
       do {
-        r = setup_comb_exp_check(NCAR(node), r, env);
-        prev = NCAR(node);
-      } while (r >= 0 && IS_NOT_NULL(node = NCDR(node)));
+        r = setup_comb_exp_check(NODE_CAR(node), r, env);
+        prev = NODE_CAR(node);
+      } while (r >= 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     }
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       int ret;
       do {
-        ret = setup_comb_exp_check(NCAR(node), state, env);
+        ret = setup_comb_exp_check(NODE_CAR(node), state, env);
         r |= ret;
-      } while (ret >= 0 && IS_NOT_NULL(node = NCDR(node)));
+      } while (ret >= 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     }
     break;
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
       int child_state = state;
       int add_state = 0;
-      QtfrNode* qn = NQTFR(node);
-      Node* target = qn->target;
+      QuantNode* qn = QUANT_(node);
+      Node* target = NODE_QUANT_BODY(qn);
       int var_num;
 
       if (! IS_REPEAT_INFINITE(qn->upper)) {
@@ -3595,11 +3562,11 @@ setup_comb_exp_check(Node* node, int state, ScanEnv* env)
 
           /* check (a*){n,m}, (a+){n,m} => (a*){n,n}, (a+){n,n} */
           if (env->backrefed_mem == 0) {
-            if (NTYPE(qn->target) == NT_ENCLOSE) {
-              EncloseNode* en = NENCLOSE(qn->target);
-              if (en->type == ENCLOSE_MEMORY) {
-                if (NTYPE(en->target) == NT_QTFR) {
-                  QtfrNode* q = NQTFR(en->target);
+            if (NODE_TYPE(NODE_QUANT_BODY(qn)) == NODE_ENCLOSURE) {
+              EnclosureNode* en = ENCLOSURE_(NODE_QUANT_BODY(qn));
+              if (en->type == ENCLOSURE_MEMORY) {
+                if (NODE_TYPE(NODE_ENCLOSURE_BODY(en)) == NODE_QUANT) {
+                  QuantNode* q = QUANT_(NODE_ENCLOSURE_BODY(en));
                   if (IS_REPEAT_INFINITE(q->upper)
                       && q->greedy == qn->greedy) {
                     qn->upper = (qn->lower == 0 ? 1 : qn->lower);
@@ -3645,33 +3612,33 @@ setup_comb_exp_check(Node* node, int state, ScanEnv* env)
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
 
       switch (en->type) {
-      case ENCLOSE_MEMORY:
+      case ENCLOSURE_MEMORY:
         {
           if (env->curr_max_regnum < en->regnum)
             env->curr_max_regnum = en->regnum;
 
-          r = setup_comb_exp_check(en->target, state, env);
+          r = setup_comb_exp_check(NODE_ENCLOSURE_BODY(en), state, env);
         }
         break;
 
       default:
-        r = setup_comb_exp_check(en->target, state, env);
+        r = setup_comb_exp_check(NODE_ENCLOSURE_BODY(en), state, env);
         break;
       }
     }
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    if (IS_CALL_RECURSION(NCALL(node)))
+  case NODE_CALL:
+    if (NODE_IS_RECURSION(node))
       env->has_recursion = 1;
     else
-      r = setup_comb_exp_check(NCALL(node)->target, state, env);
+      r = setup_comb_exp_check(NODE_BODY(node), state, env);
     break;
 #endif
 
@@ -3683,206 +3650,695 @@ setup_comb_exp_check(Node* node, int state, ScanEnv* env)
 }
 #endif
 
-#define IN_ALT        (1<<0)
-#define IN_NOT        (1<<1)
-#define IN_REPEAT     (1<<2)
-#define IN_VAR_REPEAT (1<<3)
-#define IN_CALL       (1<<4)
-#define IN_RECCALL    (1<<5)
-
-/* setup_tree does the following work.
- 1. check empty loop. (set qn->target_empty_info)
- 2. expand ignore-case in char class.
- 3. set memory status bit flags. (reg->mem_stats)
- 4. set qn->head_exact for [push, exact] -> [push_or_jump_exact1, exact].
- 5. find invalid patterns in look-behind.
- 6. expand repeated string.
- */
+#ifdef USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT
 static int
-setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
+quantifiers_memory_node_info(Node* node)
 {
-  int type;
-  int r = 0;
+  int r = QUANT_BODY_IS_EMPTY;
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     {
-      Node* prev = NULL_NODE;
+      int v;
       do {
-        r = setup_tree(NCAR(node), reg, state, env);
-        if (IS_NOT_NULL(prev) && r == 0) {
-          r = next_setup(prev, NCAR(node), reg);
+        v = quantifiers_memory_node_info(NODE_CAR(node));
+        if (v > r) r = v;
+      } while (IS_NOT_NULL(node = NODE_CDR(node)));
+    }
+    break;
+
+#ifdef USE_SUBEXP_CALL
+  case NODE_CALL:
+    if (NODE_IS_RECURSION(node)) {
+      return QUANT_BODY_IS_EMPTY_REC; /* tiny version */
+    }
+    else
+      r = quantifiers_memory_node_info(NODE_BODY(node));
+    break;
+#endif
+
+  case NODE_QUANT:
+    {
+      QuantNode* qn = QUANT_(node);
+      if (qn->upper != 0) {
+        r = quantifiers_memory_node_info(NODE_BODY(node));
+      }
+    }
+    break;
+
+  case NODE_ENCLOSURE:
+    {
+      EnclosureNode* en = ENCLOSURE_(node);
+      switch (en->type) {
+      case ENCLOSURE_MEMORY:
+        if (NODE_IS_RECURSION(node)) {
+          return QUANT_BODY_IS_EMPTY_REC;
         }
-        prev = NCAR(node);
-      } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+        return QUANT_BODY_IS_EMPTY_MEM;
+        break;
+
+      case ENCLOSURE_OPTION:
+      case ENCLOSURE_STOP_BACKTRACK:
+        r = quantifiers_memory_node_info(NODE_BODY(node));
+        break;
+      default:
+        break;
+      }
     }
     break;
 
-  case NT_ALT:
+  case NODE_BREF:
+  case NODE_STR:
+  case NODE_CTYPE:
+  case NODE_CCLASS:
+  case NODE_ANCHOR:
+  default:
+    break;
+  }
+
+  return r;
+}
+#endif /* USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT */
+
+
+#define IN_ALT          (1<<0)
+#define IN_NOT          (1<<1)
+#define IN_REAL_REPEAT  (1<<2)
+#define IN_VAR_REPEAT   (1<<3)
+#define IN_ZERO_REPEAT  (1<<4)
+#define IN_MULTI_ENTRY  (1<<5)
+
+#ifdef USE_SUBEXP_CALL
+
+#ifdef __GNUC__
+__inline
+#endif
+static int
+setup_call_node_call(CallNode* cn, ScanEnv* env, int state)
+{
+  MemEnv* mem_env = SCANENV_MEMENV(env);
+
+  if (cn->by_number != 0) {
+    int gnum = cn->group_num;
+
+#ifdef USE_NAMED_GROUP
+    if (env->num_named > 0 &&
+        IS_SYNTAX_BV(env->syntax, ONIG_SYN_CAPTURE_ONLY_NAMED_GROUP) &&
+        !ONIG_IS_OPTION_ON(env->option, ONIG_OPTION_CAPTURE_GROUP)) {
+      return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;
+    }
+#endif
+    if (gnum > env->num_mem) {
+      onig_scan_env_set_error_string(env, ONIGERR_UNDEFINED_GROUP_REFERENCE,
+                                     cn->name, cn->name_end);
+      return ONIGERR_UNDEFINED_GROUP_REFERENCE;
+    }
+
+#ifdef USE_NAMED_GROUP
+  set_call_attr:
+#endif
+    NODE_CALL_BODY(cn) = mem_env[cn->group_num].node;
+    if (IS_NULL(NODE_CALL_BODY(cn))) {
+      onig_scan_env_set_error_string(env, ONIGERR_UNDEFINED_NAME_REFERENCE,
+                                     cn->name, cn->name_end);
+      return ONIGERR_UNDEFINED_NAME_REFERENCE;
+    }
+  }
+#ifdef USE_NAMED_GROUP
+  else {
+    int *refs;
+
+    int n = onig_name_to_group_numbers(env->reg, cn->name, cn->name_end, &refs);
+    if (n <= 0) {
+      onig_scan_env_set_error_string(env, ONIGERR_UNDEFINED_NAME_REFERENCE,
+                                     cn->name, cn->name_end);
+      return ONIGERR_UNDEFINED_NAME_REFERENCE;
+    }
+    else if (n > 1) {
+      onig_scan_env_set_error_string(env, ONIGERR_MULTIPLEX_DEFINITION_NAME_CALL,
+                                     cn->name, cn->name_end);
+      return ONIGERR_MULTIPLEX_DEFINITION_NAME_CALL;
+    }
+    else {
+      cn->group_num = refs[0];
+      goto set_call_attr;
+    }
+  }
+#endif
+
+  return 0;
+}
+
+static void
+setup_call2_call(Node* node)
+{
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
     do {
-      r = setup_tree(NCAR(node), reg, (state | IN_ALT), env);
-    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
+      setup_call2_call(NODE_CAR(node));
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
-  case NT_CCLASS:
+  case NODE_QUANT:
+    setup_call2_call(NODE_BODY(node));
     break;
 
-  case NT_STR:
-    if (IS_IGNORECASE(reg->options) && !NSTRING_IS_RAW(node)) {
-      r = expand_case_fold_string(node, reg);
+  case NODE_ANCHOR:
+    if (ANCHOR_HAS_BODY(ANCHOR_(node)))
+      setup_call2_call(NODE_BODY(node));
+    break;
+
+  case NODE_ENCLOSURE:
+    if (! NODE_IS_MARK1(node)) {
+      NODE_STATUS_ADD(node, NST_MARK1);
+      setup_call2_call(NODE_BODY(node));
+      NODE_STATUS_REMOVE(node, NST_MARK1);
     }
     break;
 
-  case NT_CTYPE:
-  case NT_CANY:
+  case NODE_CALL:
+    if (! NODE_IS_MARK1(node)) {
+      NODE_STATUS_ADD(node, NST_MARK1);
+      {
+        CallNode* cn = CALL_(node);
+        Node* called = NODE_CALL_BODY(cn);
+
+        cn->entry_count++;
+
+        NODE_STATUS_ADD(called, NST_CALLED);
+        ENCLOSURE_(called)->m.entry_count++;
+        setup_call2_call(called);
+      }
+      NODE_STATUS_REMOVE(node, NST_MARK1);
+    }
     break;
 
-#ifdef USE_SUBEXP_CALL
-  case NT_CALL:
+  default:
     break;
-#endif
+  }
+}
+
+static int
+setup_call(Node* node, ScanEnv* env, int state)
+{
+  int r;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      r = setup_call(NODE_CAR(node), env, state);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_QUANT:
+    if (QUANT_(node)->upper == 0)
+      state |= IN_ZERO_REPEAT;
+
+    r = setup_call(NODE_BODY(node), env, state);
+    break;
+
+  case NODE_ANCHOR:
+    if (ANCHOR_HAS_BODY(ANCHOR_(node)))
+      r = setup_call(NODE_BODY(node), env, state);
+    else
+      r = 0;
+    break;
+
+  case NODE_ENCLOSURE:
+    if ((state & IN_ZERO_REPEAT) != 0) {
+      NODE_STATUS_ADD(node, NST_IN_ZERO_REPEAT);
+      ENCLOSURE_(node)->m.entry_count--;
+    }
+    r = setup_call(NODE_BODY(node), env, state);
+    break;
+
+  case NODE_CALL:
+    if ((state & IN_ZERO_REPEAT) != 0) {
+      NODE_STATUS_ADD(node, NST_IN_ZERO_REPEAT);
+      CALL_(node)->entry_count--;
+    }
+
+    r = setup_call_node_call(CALL_(node), env, state);
+    break;
+
+  default:
+    r = 0;
+    break;
+  }
+
+  return r;
+}
+
+static int
+setup_call2(Node* node)
+{
+  int r = 0;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      r = setup_call2(NODE_CAR(node));
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_QUANT:
+    if (QUANT_(node)->upper != 0)
+      r = setup_call2(NODE_BODY(node));
+    break;
+
+  case NODE_ANCHOR:
+    if (ANCHOR_HAS_BODY(ANCHOR_(node)))
+      r = setup_call2(NODE_BODY(node));
+    break;
+
+  case NODE_ENCLOSURE:
+    if (! NODE_IS_IN_ZERO_REPEAT(node))
+      r = setup_call2(NODE_BODY(node));
+    break;
+
+  case NODE_CALL:
+    if (! NODE_IS_IN_ZERO_REPEAT(node)) {
+      setup_call2_call(node);
+    }
+    break;
+
+  default:
+    break;
+  }
 
-  case NT_BREF:
+  return r;
+}
+
+
+static void
+setup_called_state_call(Node* node, int state)
+{
+  switch (NODE_TYPE(node)) {
+  case NODE_ALT:
+    state |= IN_ALT;
+    /* fall */
+  case NODE_LIST:
+    do {
+      setup_called_state_call(NODE_CAR(node), state);
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_QUANT:
     {
-      int i;
-      int* p;
-      Node** nodes = SCANENV_MEM_NODES(env);
-      BRefNode* br = NBREF(node);
-      p = BACKREFS_P(br);
-      for (i = 0; i < br->back_num; i++) {
-        if (p[i] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
-        BIT_STATUS_ON_AT(env->backrefed_mem, p[i]);
-        BIT_STATUS_ON_AT(env->bt_mem_start, p[i]);
-#ifdef USE_BACKREF_WITH_LEVEL
-        if (IS_BACKREF_NEST_LEVEL(br)) {
-          BIT_STATUS_ON_AT(env->bt_mem_end, p[i]);
+      QuantNode* qn = QUANT_(node);
+
+      if (IS_REPEAT_INFINITE(qn->upper) || qn->upper >= 2)
+        state |= IN_REAL_REPEAT;
+      if (qn->lower != qn->upper)
+        state |= IN_VAR_REPEAT;
+
+      setup_called_state_call(NODE_QUANT_BODY(qn), state);
+    }
+    break;
+
+  case NODE_ANCHOR:
+    {
+      AnchorNode* an = ANCHOR_(node);
+
+      switch (an->type) {
+      case ANCHOR_PREC_READ_NOT:
+      case ANCHOR_LOOK_BEHIND_NOT:
+        state |= IN_NOT;
+        /* fall */
+      case ANCHOR_PREC_READ:
+      case ANCHOR_LOOK_BEHIND:
+        setup_called_state_call(NODE_ANCHOR_BODY(an), state);
+        break;
+      default:
+        break;
+      }
+    }
+    break;
+
+  case NODE_ENCLOSURE:
+    {
+      EnclosureNode* en = ENCLOSURE_(node);
+
+      if (en->type == ENCLOSURE_MEMORY) {
+        if (NODE_IS_MARK1(node)) {
+          if ((~en->m.called_state & state) != 0) {
+            en->m.called_state |= state;
+            setup_called_state_call(NODE_BODY(node), state);
+          }
+        }
+        else {
+          NODE_STATUS_ADD(node, NST_MARK1);
+          en->m.called_state |= state;
+          setup_called_state_call(NODE_BODY(node), state);
+          NODE_STATUS_REMOVE(node, NST_MARK1);
         }
+      }
+      else {
+        setup_called_state_call(NODE_BODY(node), state);
+      }
+    }
+    break;
+
+  case NODE_CALL:
+    setup_called_state_call(NODE_BODY(node), state);
+    break;
+
+  default:
+    break;
+  }
+}
+
+static void
+setup_called_state(Node* node, int state)
+{
+  switch (NODE_TYPE(node)) {
+  case NODE_ALT:
+    state |= IN_ALT;
+    /* fall */
+  case NODE_LIST:
+    do {
+      setup_called_state(NODE_CAR(node), state);
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+#ifdef USE_SUBEXP_CALL
+  case NODE_CALL:
+    setup_called_state_call(node, state);
+    break;
 #endif
-        SET_ENCLOSE_STATUS(nodes[p[i]], NST_MEM_BACKREFED);
+
+  case NODE_ENCLOSURE:
+    {
+      EnclosureNode* en = ENCLOSURE_(node);
+
+      switch (en->type) {
+      case ENCLOSURE_MEMORY:
+        if (en->m.entry_count > 1)
+          state |= IN_MULTI_ENTRY;
+
+        en->m.called_state |= state;
+        /* fall */
+      case ENCLOSURE_OPTION:
+      case ENCLOSURE_STOP_BACKTRACK:
+        setup_called_state(NODE_BODY(node), state);
+        break;
       }
     }
     break;
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
-      OnigLen d;
-      QtfrNode* qn = NQTFR(node);
-      Node* target = qn->target;
+      QuantNode* qn = QUANT_(node);
 
-      if ((state & IN_REPEAT) != 0) {
-        qn->state |= NST_IN_REPEAT;
+      if (IS_REPEAT_INFINITE(qn->upper) || qn->upper >= 2)
+        state |= IN_REAL_REPEAT;
+      if (qn->lower != qn->upper)
+        state |= IN_VAR_REPEAT;
+
+      setup_called_state(NODE_QUANT_BODY(qn), state);
+    }
+    break;
+
+  case NODE_ANCHOR:
+    {
+      AnchorNode* an = ANCHOR_(node);
+
+      switch (an->type) {
+      case ANCHOR_PREC_READ_NOT:
+      case ANCHOR_LOOK_BEHIND_NOT:
+        state |= IN_NOT;
+        /* fall */
+      case ANCHOR_PREC_READ:
+      case ANCHOR_LOOK_BEHIND:
+        setup_called_state(NODE_ANCHOR_BODY(an), state);
+        break;
+      default:
+        break;
       }
+    }
+    break;
 
-      if (IS_REPEAT_INFINITE(qn->upper) || qn->upper >= 1) {
-        r = get_min_len(target, &d, env);
-        if (r) break;
-        if (d == 0) {
-          qn->target_empty_info = NQ_TARGET_IS_EMPTY;
-#ifdef USE_MONOMANIAC_CHECK_CAPTURES_IN_ENDLESS_REPEAT
-          r = quantifiers_memory_node_info(target);
-          if (r < 0) break;
-          if (r > 0) {
-            qn->target_empty_info = r;
-          }
+  case NODE_BREF:
+  case NODE_STR:
+  case NODE_CTYPE:
+  case NODE_CCLASS:
+  default:
+    break;
+  }
+}
+
+#endif  /* USE_SUBEXP_CALL */
+
+
+static int setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env);
+
+#ifdef __GNUC__
+__inline
 #endif
-#if 0
-          r = get_max_len(target, &d, env);
-          if (r == 0 && d == 0) {
-            /*  ()* ==> ()?, ()+ ==> ()  */
-            qn->upper = 1;
-            if (qn->lower > 1) qn->lower = 1;
-            if (NTYPE(target) == NT_STR) {
-              qn->upper = qn->lower = 0;  /* /(?:)+/ ==> // */
-            }
-          }
+static int
+setup_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
+{
+/* allowed node types in look-behind */
+#define ALLOWED_TYPE_IN_LB \
+  ( BIT_NODE_LIST | BIT_NODE_ALT | BIT_NODE_STR | BIT_NODE_CCLASS | BIT_NODE_CTYPE \
+  | BIT_NODE_ANCHOR | BIT_NODE_ENCLOSURE | BIT_NODE_QUANT | BIT_NODE_CALL )
+
+#define ALLOWED_ENCLOSURE_IN_LB       ( ENCLOSURE_MEMORY | ENCLOSURE_OPTION )
+#define ALLOWED_ENCLOSURE_IN_LB_NOT   ENCLOSURE_OPTION
+
+#define ALLOWED_ANCHOR_IN_LB \
+  ( ANCHOR_LOOK_BEHIND | ANCHOR_BEGIN_LINE | ANCHOR_END_LINE | ANCHOR_BEGIN_BUF \
+  | ANCHOR_BEGIN_POSITION | ANCHOR_WORD_BOUND | ANCHOR_NOT_WORD_BOUND \
+  | ANCHOR_WORD_BEGIN | ANCHOR_WORD_END )
+
+#define ALLOWED_ANCHOR_IN_LB_NOT \
+  ( ANCHOR_LOOK_BEHIND | ANCHOR_LOOK_BEHIND_NOT | ANCHOR_BEGIN_LINE \
+  | ANCHOR_END_LINE | ANCHOR_BEGIN_BUF | ANCHOR_BEGIN_POSITION | ANCHOR_WORD_BOUND \
+  | ANCHOR_NOT_WORD_BOUND | ANCHOR_WORD_BEGIN | ANCHOR_WORD_END )
+
+  int r;
+  AnchorNode* an = ANCHOR_(node);
+
+  switch (an->type) {
+  case ANCHOR_PREC_READ:
+    r = setup_tree(NODE_ANCHOR_BODY(an), reg, state, env);
+    break;
+  case ANCHOR_PREC_READ_NOT:
+    r = setup_tree(NODE_ANCHOR_BODY(an), reg, (state | IN_NOT), env);
+    break;
+
+  case ANCHOR_LOOK_BEHIND:
+    {
+      r = check_type_tree(NODE_ANCHOR_BODY(an), ALLOWED_TYPE_IN_LB,
+                          ALLOWED_ENCLOSURE_IN_LB, ALLOWED_ANCHOR_IN_LB);
+      if (r < 0) return r;
+      if (r > 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
+      r = setup_tree(NODE_ANCHOR_BODY(an), reg, state, env);
+      if (r != 0) return r;
+      r = setup_look_behind(node, reg, env);
+    }
+    break;
+
+  case ANCHOR_LOOK_BEHIND_NOT:
+    {
+      r = check_type_tree(NODE_ANCHOR_BODY(an), ALLOWED_TYPE_IN_LB,
+                          ALLOWED_ENCLOSURE_IN_LB_NOT, ALLOWED_ANCHOR_IN_LB_NOT);
+      if (r < 0) return r;
+      if (r > 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
+      r = setup_tree(NODE_ANCHOR_BODY(an), reg, (state | IN_NOT), env);
+      if (r != 0) return r;
+      r = setup_look_behind(node, reg, env);
+    }
+    break;
+
+  default:
+    r = 0;
+    break;
+  }
+
+  return r;
+}
+
+#ifdef __GNUC__
+__inline
 #endif
+static int
+setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
+{
+  int r;
+  OnigLen d;
+  QuantNode* qn = QUANT_(node);
+  Node* body = NODE_BODY(node);
+
+  if ((state & IN_REAL_REPEAT) != 0) {
+    NODE_STATUS_ADD(node, NST_IN_REAL_REPEAT);
+  }
+  if ((state & IN_MULTI_ENTRY) != 0) {
+    NODE_STATUS_ADD(node, NST_IN_MULTI_ENTRY);
+  }
+
+  if (IS_REPEAT_INFINITE(qn->upper) || qn->upper >= 1) {
+    d = get_min_len(body, env);
+    if (d == 0) {
+#ifdef USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT
+      qn->body_empty_info = quantifiers_memory_node_info(body);
+      if (qn->body_empty_info == QUANT_BODY_IS_EMPTY_REC) {
+        if (NODE_TYPE(body) == NODE_ENCLOSURE &&
+            ENCLOSURE_(body)->type == ENCLOSURE_MEMORY) {
+          MEM_STATUS_ON(env->bt_mem_end, ENCLOSURE_(body)->m.regnum);
         }
       }
+#else
+      qn->body_empty_info = QUANT_BODY_IS_EMPTY;
+#endif
+    }
+  }
 
-      state |= IN_REPEAT;
-      if (qn->lower != qn->upper)
-        state |= IN_VAR_REPEAT;
-      r = setup_tree(target, reg, state, env);
-      if (r) break;
+  if (IS_REPEAT_INFINITE(qn->upper) || qn->upper >= 2)
+    state |= IN_REAL_REPEAT;
+  if (qn->lower != qn->upper)
+    state |= IN_VAR_REPEAT;
+
+  r = setup_tree(body, reg, state, env);
+  if (r != 0) return r;
 
-      /* expand string */
+  /* expand string */
 #define EXPAND_STRING_MAX_LENGTH  100
-      if (NTYPE(target) == NT_STR) {
-        if (!IS_REPEAT_INFINITE(qn->lower) && qn->lower == qn->upper &&
-            qn->lower > 1 && qn->lower <= EXPAND_STRING_MAX_LENGTH) {
-          int len = NSTRING_LEN(target);
-          StrNode* sn = NSTR(target);
-
-          if (len * qn->lower <= EXPAND_STRING_MAX_LENGTH) {
-            int i, n = qn->lower;
-            onig_node_conv_to_str_node(node, NSTR(target)->flag);
-            for (i = 0; i < n; i++) {
-              r = onig_node_str_cat(node, sn->s, sn->end);
-              if (r) break;
-            }
-            onig_node_free(target);
-            break; /* break case NT_QTFR: */
-          }
+  if (NODE_TYPE(body) == NODE_STR) {
+    if (!IS_REPEAT_INFINITE(qn->lower) && qn->lower == qn->upper &&
+        qn->lower > 1 && qn->lower <= EXPAND_STRING_MAX_LENGTH) {
+      int len = NSTRING_LEN(body);
+      StrNode* sn = STR_(body);
+
+      if (len * qn->lower <= EXPAND_STRING_MAX_LENGTH) {
+        int i, n = qn->lower;
+        onig_node_conv_to_str_node(node, STR_(body)->flag);
+        for (i = 0; i < n; i++) {
+          r = onig_node_str_cat(node, sn->s, sn->end);
+          if (r != 0) return r;
         }
+        onig_node_free(body);
+        return r;
       }
+    }
+  }
 
 #ifdef USE_OP_PUSH_OR_JUMP_EXACT
-      if (qn->greedy && (qn->target_empty_info != 0)) {
-        if (NTYPE(target) == NT_QTFR) {
-          QtfrNode* tqn = NQTFR(target);
-          if (IS_NOT_NULL(tqn->head_exact)) {
-            qn->head_exact  = tqn->head_exact;
-            tqn->head_exact = NULL;
-          }
+  if (qn->greedy && (qn->body_empty_info != 0)) {
+    if (NODE_TYPE(body) == NODE_QUANT) {
+      QuantNode* tqn = QUANT_(body);
+      if (IS_NOT_NULL(tqn->head_exact)) {
+        qn->head_exact  = tqn->head_exact;
+        tqn->head_exact = NULL;
+      }
+    }
+    else {
+      qn->head_exact = get_head_value_node(NODE_BODY(node), 1, reg);
+    }
+  }
+#endif
+
+  return r;
+}
+
+/* setup_tree does the following work.
+ 1. check empty loop. (set qn->body_empty_info)
+ 2. expand ignore-case in char class.
+ 3. set memory status bit flags. (reg->mem_stats)
+ 4. set qn->head_exact for [push, exact] -> [push_or_jump_exact1, exact].
+ 5. find invalid patterns in look-behind.
+ 6. expand repeated string.
+ */
+static int
+setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
+{
+  int r = 0;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+    {
+      Node* prev = NULL_NODE;
+      do {
+        r = setup_tree(NODE_CAR(node), reg, state, env);
+        if (IS_NOT_NULL(prev) && r == 0) {
+          r = next_setup(prev, NODE_CAR(node), reg);
         }
-        else {
-          qn->head_exact = get_head_value_node(qn->target, 1, reg);
+        prev = NODE_CAR(node);
+      } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    }
+    break;
+
+  case NODE_ALT:
+    do {
+      r = setup_tree(NODE_CAR(node), reg, (state | IN_ALT), env);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_STR:
+    if (IS_IGNORECASE(reg->options) && !NSTRING_IS_RAW(node)) {
+      r = expand_case_fold_string(node, reg);
+    }
+    break;
+
+  case NODE_BREF:
+    {
+      int i;
+      int* p;
+      BRefNode* br = BREF_(node);
+      p = BACKREFS_P(br);
+      for (i = 0; i < br->back_num; i++) {
+        if (p[i] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
+        MEM_STATUS_ON(env->backrefed_mem, p[i]);
+        MEM_STATUS_ON(env->bt_mem_start, p[i]);
+#ifdef USE_BACKREF_WITH_LEVEL
+        if (NODE_IS_NEST_LEVEL(node)) {
+          MEM_STATUS_ON(env->bt_mem_end, p[i]);
         }
-      }
 #endif
+      }
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
 
       switch (en->type) {
-      case ENCLOSE_OPTION:
+      case ENCLOSURE_OPTION:
         {
           OnigOptionType options = reg->options;
-          reg->options = NENCLOSE(node)->option;
-          r = setup_tree(NENCLOSE(node)->target, reg, state, env);
+          reg->options = ENCLOSURE_(node)->o.option;
+          r = setup_tree(NODE_BODY(node), reg, state, env);
           reg->options = options;
         }
         break;
 
-      case ENCLOSE_MEMORY:
-        if ((state & (IN_ALT | IN_NOT | IN_VAR_REPEAT | IN_CALL)) != 0) {
-          BIT_STATUS_ON_AT(env->bt_mem_start, en->regnum);
-          /* SET_ENCLOSE_STATUS(node, NST_MEM_IN_ALT_NOT); */
+      case ENCLOSURE_MEMORY:
+#ifdef USE_SUBEXP_CALL
+        state |= en->m.called_state;
+#endif
+
+        if ((state & (IN_ALT | IN_NOT | IN_VAR_REPEAT | IN_MULTI_ENTRY)) != 0
+            || NODE_IS_RECURSION(node)) {
+          MEM_STATUS_ON(env->bt_mem_start, en->m.regnum);
         }
-        if (IS_ENCLOSE_CALLED(en))
-          state |= IN_CALL;
-        if (IS_ENCLOSE_RECURSION(en))
-          state |= IN_RECCALL;
-        else if ((state & IN_RECCALL) != 0)
-          SET_CALL_RECURSION(node);
-        r = setup_tree(en->target, reg, state, env);
+        r = setup_tree(NODE_BODY(node), reg, state, env);
         break;
 
-      case ENCLOSE_STOP_BACKTRACK:
+      case ENCLOSURE_STOP_BACKTRACK:
         {
-          Node* target = en->target;
+          Node* target = NODE_BODY(node);
           r = setup_tree(target, reg, state, env);
-          if (NTYPE(target) == NT_QTFR) {
-            QtfrNode* tqn = NQTFR(target);
+          if (NODE_TYPE(target) == NODE_QUANT) {
+            QuantNode* tqn = QUANT_(target);
             if (IS_REPEAT_INFINITE(tqn->upper) && tqn->lower <= 1 &&
                 tqn->greedy != 0) {  /* (?>a*), a*+ etc... */
-              int qtype = NTYPE(tqn->target);
-              if (IS_NODE_TYPE_SIMPLE(qtype))
-                SET_ENCLOSE_STATUS(node, NST_STOP_BT_SIMPLE_REPEAT);
+              if (NODE_IS_SIMPLE_TYPE(NODE_BODY(target)))
+                NODE_STATUS_ADD(node, NST_STOP_BT_SIMPLE_REPEAT);
             }
           }
         }
@@ -3891,59 +4347,19 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
     }
     break;
 
-  case NT_ANCHOR:
-    {
-      AnchorNode* an = NANCHOR(node);
-
-      switch (an->type) {
-      case ANCHOR_PREC_READ:
-        r = setup_tree(an->target, reg, state, env);
-        break;
-      case ANCHOR_PREC_READ_NOT:
-        r = setup_tree(an->target, reg, (state | IN_NOT), env);
-        break;
-
-/* allowed node types in look-behind */
-#define ALLOWED_TYPE_IN_LB  \
-  ( BIT_NT_LIST | BIT_NT_ALT | BIT_NT_STR | BIT_NT_CCLASS | BIT_NT_CTYPE | \
-    BIT_NT_CANY | BIT_NT_ANCHOR | BIT_NT_ENCLOSE | BIT_NT_QTFR | BIT_NT_CALL )
-
-#define ALLOWED_ENCLOSE_IN_LB       ( ENCLOSE_MEMORY | ENCLOSE_OPTION )
-#define ALLOWED_ENCLOSE_IN_LB_NOT   ENCLOSE_OPTION
-
-#define ALLOWED_ANCHOR_IN_LB \
-( ANCHOR_LOOK_BEHIND | ANCHOR_BEGIN_LINE | ANCHOR_END_LINE | ANCHOR_BEGIN_BUF | ANCHOR_BEGIN_POSITION | ANCHOR_WORD_BOUND | ANCHOR_NOT_WORD_BOUND | ANCHOR_WORD_BEGIN | ANCHOR_WORD_END )
-
-#define ALLOWED_ANCHOR_IN_LB_NOT \
-( ANCHOR_LOOK_BEHIND | ANCHOR_LOOK_BEHIND_NOT | ANCHOR_BEGIN_LINE | ANCHOR_END_LINE | ANCHOR_BEGIN_BUF | ANCHOR_BEGIN_POSITION | ANCHOR_WORD_BOUND | ANCHOR_NOT_WORD_BOUND | ANCHOR_WORD_BEGIN | ANCHOR_WORD_END )
-
-      case ANCHOR_LOOK_BEHIND:
-        {
-          r = check_type_tree(an->target, ALLOWED_TYPE_IN_LB,
-                              ALLOWED_ENCLOSE_IN_LB, ALLOWED_ANCHOR_IN_LB);
-          if (r < 0) return r;
-          if (r > 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
-          r = setup_tree(an->target, reg, state, env);
-          if (r != 0) return r;
-          r = setup_look_behind(node, reg, env);
-        }
-        break;
+  case NODE_QUANT:
+    r = setup_quant(node, reg, state, env);
+    break;
 
-      case ANCHOR_LOOK_BEHIND_NOT:
-        {
-          r = check_type_tree(an->target, ALLOWED_TYPE_IN_LB,
-                   ALLOWED_ENCLOSE_IN_LB_NOT, ALLOWED_ANCHOR_IN_LB_NOT);
-          if (r < 0) return r;
-          if (r > 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
-          r = setup_tree(an->target, reg, (state | IN_NOT), env);
-          if (r != 0) return r;
-          r = setup_look_behind(node, reg, env);
-        }
-        break;
-      }
-    }
+  case NODE_ANCHOR:
+    r = setup_anchor(node, reg, state, env);
     break;
 
+#ifdef USE_SUBEXP_CALL
+  case NODE_CALL:
+#endif
+  case NODE_CTYPE:
+  case NODE_CCLASS:
   default:
     break;
   }
@@ -4594,15 +5010,13 @@ alt_merge_node_opt_info(NodeOptInfo* to, NodeOptInfo* add, OptEnv* env)
 static int
 optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
 {
-  int type;
   int r = 0;
 
   clear_node_opt_info(opt);
   set_bound_node_opt_info(opt, &env->mmd);
 
-  type = NTYPE(node);
-  switch (type) {
-  case NT_LIST:
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
     {
       OptEnv nenv;
       NodeOptInfo nopt;
@@ -4610,33 +5024,33 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
 
       copy_opt_env(&nenv, env);
       do {
-        r = optimize_node_left(NCAR(nd), &nopt, &nenv);
+        r = optimize_node_left(NODE_CAR(nd), &nopt, &nenv);
         if (r == 0) {
           add_mml(&nenv.mmd, &nopt.len);
           concat_left_node_opt_info(env->enc, opt, &nopt);
         }
-      } while (r == 0 && IS_NOT_NULL(nd = NCDR(nd)));
+      } while (r == 0 && IS_NOT_NULL(nd = NODE_CDR(nd)));
     }
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     {
       NodeOptInfo nopt;
       Node* nd = node;
 
       do {
-        r = optimize_node_left(NCAR(nd), &nopt, env);
+        r = optimize_node_left(NODE_CAR(nd), &nopt, env);
         if (r == 0) {
           if (nd == node) copy_node_opt_info(opt, &nopt);
           else            alt_merge_node_opt_info(opt, &nopt, env);
         }
-      } while ((r == 0) && IS_NOT_NULL(nd = NCDR(nd)));
+      } while ((r == 0) && IS_NOT_NULL(nd = NODE_CDR(nd)));
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     {
-      StrNode* sn = NSTR(node);
+      StrNode* sn = STR_(node);
       int slen = sn->end - sn->s;
       int is_raw = NSTRING_IS_RAW(node);
 
@@ -4677,10 +5091,10 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
     }
     break;
 
-  case NT_CCLASS:
+  case NODE_CCLASS:
     {
       int i, z;
-      CClassNode* cc = NCCLASS(node);
+      CClassNode* cc = CCLASS_(node);
 
       /* no need to check ignore case. (set in setup_tree()) */
 
@@ -4702,7 +5116,7 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
     }
     break;
 
-  case NT_CTYPE:
+  case NODE_CTYPE:
     {
       int i, min, max;
 
@@ -4711,9 +5125,12 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
       if (max == 1) {
         min = 1;
 
-        switch (NCTYPE(node)->ctype) {
+        switch (CTYPE_(node)->ctype) {
+        case CTYPE_ANYCHAR:
+          break;
+
         case ONIGENC_CTYPE_WORD:
-          if (NCTYPE(node)->not != 0) {
+          if (CTYPE_(node)->not != 0) {
             for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
               if (! ONIGENC_IS_CODE_WORD(env->enc, i)) {
                 add_char_opt_map_info(&opt->map, (UChar )i, env->enc);
@@ -4737,16 +5154,8 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
     }
     break;
 
-  case NT_CANY:
-    {
-      OnigLen min = ONIGENC_MBC_MINLEN(env->enc);
-      OnigLen max = ONIGENC_MBC_MAXLEN_DIST(env->enc);
-      set_mml(&opt->len, min, max);
-    }
-    break;
-
-  case NT_ANCHOR:
-    switch (NANCHOR(node)->type) {
+  case NODE_ANCHOR:
+    switch (ANCHOR_(node)->type) {
     case ANCHOR_BEGIN_BUF:
     case ANCHOR_BEGIN_POSITION:
     case ANCHOR_BEGIN_LINE:
@@ -4755,14 +5164,14 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
     case ANCHOR_END_LINE:
     case ANCHOR_PREC_READ_NOT:
     case ANCHOR_LOOK_BEHIND:
-      add_opt_anc_info(&opt->anc, NANCHOR(node)->type);
+      add_opt_anc_info(&opt->anc, ANCHOR_(node)->type);
       break;
 
     case ANCHOR_PREC_READ:
       {
         NodeOptInfo nopt;
 
-        r = optimize_node_left(NANCHOR(node)->target, &nopt, env);
+        r = optimize_node_left(NODE_BODY(node), &nopt, env);
         if (r == 0) {
           if (nopt.exb.len > 0)
             copy_opt_exact_info(&opt->expr, &nopt.exb);
@@ -4782,61 +5191,57 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
     }
     break;
 
-  case NT_BREF:
+  case NODE_BREF:
     {
       int i;
       int* backs;
       OnigLen min, max, tmin, tmax;
-      Node** nodes = SCANENV_MEM_NODES(env->scan_env);
-      BRefNode* br = NBREF(node);
+      MemEnv* mem_env = SCANENV_MEMENV(env->scan_env);
+      BRefNode* br = BREF_(node);
 
-      if (br->state & NST_RECURSION) {
+      if (NODE_IS_RECURSION(node)) {
         set_mml(&opt->len, 0, ONIG_INFINITE_DISTANCE);
         break;
       }
       backs = BACKREFS_P(br);
-      r = get_min_len(nodes[backs[0]], &min, env->scan_env);
-      if (r != 0) break;
-      r = get_max_len(nodes[backs[0]], &max, env->scan_env);
-      if (r != 0) break;
+      min = get_min_len(mem_env[backs[0]].node, env->scan_env);
+      max = get_max_len(mem_env[backs[0]].node, env->scan_env);
       for (i = 1; i < br->back_num; i++) {
-        r = get_min_len(nodes[backs[i]], &tmin, env->scan_env);
-        if (r != 0) break;
-        r = get_max_len(nodes[backs[i]], &tmax, env->scan_env);
-        if (r != 0) break;
+        tmin = get_min_len(mem_env[backs[i]].node, env->scan_env);
+        tmax = get_max_len(mem_env[backs[i]].node, env->scan_env);
         if (min > tmin) min = tmin;
         if (max < tmax) max = tmax;
       }
-      if (r == 0) set_mml(&opt->len, min, max);
+      set_mml(&opt->len, min, max);
     }
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
-    if (IS_CALL_RECURSION(NCALL(node)))
+  case NODE_CALL:
+    if (NODE_IS_RECURSION(node))
       set_mml(&opt->len, 0, ONIG_INFINITE_DISTANCE);
     else {
       OnigOptionType save = env->options;
-      env->options = NENCLOSE(NCALL(node)->target)->option;
-      r = optimize_node_left(NCALL(node)->target, opt, env);
+      env->options = ENCLOSURE_(NODE_BODY(node))->o.option;
+      r = optimize_node_left(NODE_BODY(node), opt, env);
       env->options = save;
     }
     break;
 #endif
 
-  case NT_QTFR:
+  case NODE_QUANT:
     {
       int i;
       OnigLen min, max;
       NodeOptInfo nopt;
-      QtfrNode* qn = NQTFR(node);
+      QuantNode* qn = QUANT_(node);
 
-      r = optimize_node_left(qn->target, &nopt, env);
-      if (r) break;
+      r = optimize_node_left(NODE_BODY(node), &nopt, env);
+      if (r != 0) break;
 
       if (qn->lower == 0 && IS_REPEAT_INFINITE(qn->upper)) {
         if (env->mmd.max == 0 &&
-            NTYPE(qn->target) == NT_CANY && qn->greedy) {
+            NODE_IS_ANYCHAR(NODE_BODY(node)) && qn->greedy != 0) {
           if (IS_MULTILINE(env->options))
             add_opt_anc_info(&opt->anc, ANCHOR_ANYCHAR_STAR_ML);
           else
@@ -4877,22 +5282,22 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
     }
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     {
-      EncloseNode* en = NENCLOSE(node);
+      EnclosureNode* en = ENCLOSURE_(node);
 
       switch (en->type) {
-      case ENCLOSE_OPTION:
+      case ENCLOSURE_OPTION:
         {
           OnigOptionType save = env->options;
 
-          env->options = en->option;
-          r = optimize_node_left(en->target, opt, env);
+          env->options = en->o.option;
+          r = optimize_node_left(NODE_BODY(node), opt, env);
           env->options = save;
         }
         break;
 
-      case ENCLOSE_MEMORY:
+      case ENCLOSURE_MEMORY:
 #ifdef USE_SUBEXP_CALL
         en->opt_count++;
         if (en->opt_count > MAX_NODE_OPT_INFO_REF_COUNT) {
@@ -4900,24 +5305,24 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
 
           min = 0;
           max = ONIG_INFINITE_DISTANCE;
-          if (IS_ENCLOSE_MIN_FIXED(en)) min = en->min_len;
-          if (IS_ENCLOSE_MAX_FIXED(en)) max = en->max_len;
+          if (NODE_IS_MIN_FIXED(node)) min = en->min_len;
+          if (NODE_IS_MAX_FIXED(node)) max = en->max_len;
           set_mml(&opt->len, min, max);
         }
         else
 #endif
           {
-            r = optimize_node_left(en->target, opt, env);
+            r = optimize_node_left(NODE_BODY(node), opt, env);
 
             if (is_set_opt_anc_info(&opt->anc, ANCHOR_ANYCHAR_STAR_MASK)) {
-              if (BIT_STATUS_AT(env->scan_env->backrefed_mem, en->regnum))
+              if (MEM_STATUS_AT0(env->scan_env->backrefed_mem, en->m.regnum))
                 remove_opt_anc_info(&opt->anc, ANCHOR_ANYCHAR_STAR_MASK);
             }
           }
         break;
 
-      case ENCLOSE_STOP_BACKTRACK:
-        r = optimize_node_left(en->target, opt, env);
+      case ENCLOSURE_STOP_BACKTRACK:
+        r = optimize_node_left(NODE_BODY(node), opt, env);
         break;
       }
     }
@@ -4925,8 +5330,7 @@ optimize_node_left(Node* node, NodeOptInfo* opt, OptEnv* env)
 
   default:
 #ifdef ONIG_DEBUG
-    fprintf(stderr, "optimize_node_left: undefined node type %d\n",
-	    NTYPE(node));
+    fprintf(stderr, "optimize_node_left: undefined node type %d\n", NODE_TYPE(node));
 #endif
     r = ONIGERR_TYPE_BUG;
     break;
@@ -4962,7 +5366,7 @@ set_optimize_exact_info(regex_t* reg, OptExactInfo* e)
     if (e->len >= 3 || (e->len >= 2 && allow_reverse)) {
       r = set_bm_skip(reg->exact, reg->exact_end, reg->enc,
 	              reg->map, &(reg->int_map));
-      if (r) return r;
+      if (r != 0) return r;
 
       reg->optimize = (allow_reverse != 0
 		       ? ONIG_OPTIMIZE_EXACT_BM : ONIG_OPTIMIZE_EXACT_BM_NOT_REV);
@@ -5006,7 +5410,7 @@ set_sub_anchor(regex_t* reg, OptAncInfo* anc)
   reg->sub_anchor |= anc->right_anchor & ANCHOR_END_LINE;
 }
 
-#ifdef ONIG_DEBUG
+#if defined(ONIG_DEBUG_COMPILE) || defined(ONIG_DEBUG_MATCH)
 static void print_optimize_info(FILE* f, regex_t* reg);
 #endif
 
@@ -5025,7 +5429,7 @@ set_optimize_info_from_tree(Node* node, regex_t* reg, ScanEnv* scan_env)
   clear_mml(&env.mmd);
 
   r = optimize_node_left(node, &opt, &env);
-  if (r) return r;
+  if (r != 0) return r;
 
   reg->anchor = opt.anc.left_anchor & (ANCHOR_BEGIN_BUF |
         ANCHOR_BEGIN_POSITION | ANCHOR_ANYCHAR_STAR | ANCHOR_ANYCHAR_STAR_ML |
@@ -5120,6 +5524,10 @@ static void print_enc_string(FILE* fp, OnigEncoding enc,
   fprintf(fp, "/\n");
 }
 
+#endif /* ONIG_DEBUG */
+
+#if defined(ONIG_DEBUG_COMPILE) || defined(ONIG_DEBUG_MATCH)
+
 static void
 print_distance_range(FILE* f, OnigLen a, OnigLen b)
 {
@@ -5236,7 +5644,7 @@ print_optimize_info(FILE* f, regex_t* reg)
     }
   }
 }
-#endif /* ONIG_DEBUG */
+#endif
 
 
 extern void
@@ -5278,7 +5686,7 @@ onig_transfer(regex_t* to, regex_t* from)
 }
 
 
-#ifdef ONIG_DEBUG
+#ifdef ONIG_DEBUG_COMPILE
 static void print_compiled_byte_code_list P_((FILE* f, regex_t* reg));
 #endif
 #ifdef ONIG_DEBUG_PARSE_TREE
@@ -5323,14 +5731,14 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   reg->num_comb_exp_check = 0;
 #endif
 
-  r = onig_parse_make_tree(&root, pattern, pattern_end, reg, &scan_env);
+  r = onig_parse_tree(&root, pattern, pattern_end, reg, &scan_env);
   if (r != 0) goto err;
 
 #ifdef USE_NAMED_GROUP
   /* mixed use named group and no-named group */
   if (scan_env.num_named > 0 &&
       IS_SYNTAX_BV(scan_env.syntax, ONIG_SYN_CAPTURE_ONLY_NAMED_GROUP) &&
-      !ONIG_IS_OPTION_ON(reg->options, ONIG_OPTION_CAPTURE_GROUP)) {
+      ! ONIG_IS_OPTION_ON(reg->options, ONIG_OPTION_CAPTURE_GROUP)) {
     if (scan_env.num_named != scan_env.num_mem)
       r = disable_noname_group_capture(&root, reg, &scan_env);
     else
@@ -5340,22 +5748,27 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   }
 #endif
 
+  r = check_backrefs(root, &scan_env);
+  if (r != 0) goto err;
+
 #ifdef USE_SUBEXP_CALL
   if (scan_env.num_call > 0) {
     r = unset_addr_list_init(&uslist, scan_env.num_call);
     if (r != 0) goto err;
     scan_env.unset_addr_list = &uslist;
-    r = setup_subexp_call(root, &scan_env);
+    r = setup_call(root, &scan_env, 0);
+    if (r != 0) goto err_unset;
+    r = setup_call2(root);
     if (r != 0) goto err_unset;
-    r = subexp_recursive_check_trav(root, &scan_env);
+    r = recursive_call_check_trav(root, &scan_env, 0);
     if (r  < 0) goto err_unset;
-    r = subexp_inf_recursive_check_trav(root, &scan_env);
+    r = infinite_recursive_call_check_trav(root, &scan_env);
     if (r != 0) goto err_unset;
 
-    reg->num_call = scan_env.num_call;
+    setup_called_state(root, 0);
   }
-  else
-    reg->num_call = 0;
+
+  reg->num_call = scan_env.num_call;
 #endif
 
   r = setup_tree(root, reg, 0, &scan_env);
@@ -5369,11 +5782,12 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   reg->bt_mem_start     = scan_env.bt_mem_start;
   reg->bt_mem_start    |= reg->capture_history;
   if (IS_FIND_CONDITION(reg->options))
-    BIT_STATUS_ON_ALL(reg->bt_mem_end);
+    MEM_STATUS_ON_ALL(reg->bt_mem_end);
   else {
     reg->bt_mem_end  = scan_env.bt_mem_end;
     reg->bt_mem_end |= reg->capture_history;
   }
+  reg->bt_mem_start |= reg->bt_mem_end;
 
 #ifdef USE_COMBINATION_EXPLOSION_CHECK
   if (scan_env.backrefed_mem == 0
@@ -5391,7 +5805,7 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
     if (scan_env.comb_exp_max_regnum > 0) {
       int i;
       for (i = 1; i <= scan_env.comb_exp_max_regnum; i++) {
-        if (BIT_STATUS_AT(scan_env.backrefed_mem, i) != 0) {
+        if (MEM_STATUS_AT(scan_env.backrefed_mem, i) != 0) {
           scan_env.num_comb_exp_check = 0;
           break;
         }
@@ -5408,19 +5822,19 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   if (r != 0) goto err_unset;
 #endif
 
-  if (IS_NOT_NULL(scan_env.mem_nodes_dynamic)) {
-    xfree(scan_env.mem_nodes_dynamic);
-    scan_env.mem_nodes_dynamic = (Node** )NULL;
+  if (IS_NOT_NULL(scan_env.mem_env_dynamic)) {
+    xfree(scan_env.mem_env_dynamic);
+    scan_env.mem_env_dynamic = (MemEnv* )NULL;
   }
 
-  r = compile_tree(root, reg);
+  r = compile_tree(root, reg, &scan_env);
   if (r == 0) {
     r = add_opcode(reg, OP_END);
 #ifdef USE_SUBEXP_CALL
     if (scan_env.num_call > 0) {
       r = unset_addr_list_fix(&uslist, reg);
       unset_addr_list_end(&uslist);
-      if (r) goto err;
+      if (r != 0) goto err;
     }
 #endif
 
@@ -5466,8 +5880,8 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   }
 
   onig_node_free(root);
-  if (IS_NOT_NULL(scan_env.mem_nodes_dynamic))
-      xfree(scan_env.mem_nodes_dynamic);
+  if (IS_NOT_NULL(scan_env.mem_env_dynamic))
+      xfree(scan_env.mem_env_dynamic);
   return r;
 }
 
@@ -5543,7 +5957,7 @@ onig_new_without_alloc(regex_t* reg, const UChar* pattern,
   int r;
 
   r = onig_reg_init(reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
-  if (r) return r;
+  if (r != 0) return r;
 
   r = onig_compile(reg, pattern, pattern_end, einfo);
   return r;
@@ -5560,10 +5974,10 @@ onig_new(regex_t** reg, const UChar* pattern, const UChar* pattern_end,
   if (IS_NULL(*reg)) return ONIGERR_MEMORY;
 
   r = onig_reg_init(*reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
-  if (r) goto err;
+  if (r != 0) goto err;
 
   r = onig_compile(*reg, pattern, pattern_end, einfo);
-  if (r) {
+  if (r != 0) {
   err:
     onig_free(*reg);
     *reg = NULL;
@@ -5657,9 +6071,10 @@ onig_is_in_code_range(const UChar* p, OnigCodePoint code)
 }
 
 extern int
-onig_is_code_in_cc_len(int elen, OnigCodePoint code, CClassNode* cc)
+onig_is_code_in_cc_len(int elen, OnigCodePoint code, /* CClassNode* */ void* cc_arg)
 {
   int found;
+  CClassNode* cc = (CClassNode* )cc_arg;
 
   if (elen > 1 || (code >= SINGLE_BYTE_SIZE)) {
     if (IS_NULL(cc->mbuf)) {
@@ -5775,10 +6190,10 @@ OnigOpInfoType OnigOpInfo[] = {
   { OP_REPEAT_INC_NG,       "repeat-inc-ng",        ARG_MEMNUM  },
   { OP_REPEAT_INC_SG,       "repeat-inc-sg",        ARG_MEMNUM  },
   { OP_REPEAT_INC_NG_SG,    "repeat-inc-ng-sg",     ARG_MEMNUM  },
-  { OP_NULL_CHECK_START,    "null-check-start",     ARG_MEMNUM  },
-  { OP_NULL_CHECK_END,      "null-check-end",       ARG_MEMNUM  },
-  { OP_NULL_CHECK_END_MEMST,"null-check-end-memst", ARG_MEMNUM  },
-  { OP_NULL_CHECK_END_MEMST_PUSH,"null-check-end-memst-push", ARG_MEMNUM  },
+  { OP_EMPTY_CHECK_START,   "empty-check-start",    ARG_MEMNUM  },
+  { OP_EMPTY_CHECK_END,     "empty-check-end",      ARG_MEMNUM  },
+  { OP_EMPTY_CHECK_END_MEMST,"empty-check-end-memst", ARG_MEMNUM  },
+  { OP_EMPTY_CHECK_END_MEMST_PUSH,"empty-check-end-memst-push", ARG_MEMNUM  },
   { OP_PUSH_POS,             "push-pos",             ARG_NON },
   { OP_POP_POS,              "pop-pos",              ARG_NON },
   { OP_PUSH_POS_NOT,         "push-pos-not",         ARG_RELADDR },
@@ -5824,13 +6239,6 @@ op2arg_type(int opcode)
 }
 
 static void
-Indent(FILE* f, int indent)
-{
-  int i;
-  for (i = 0; i < indent; i++) putc(' ', f);
-}
-
-static void
 p_string(FILE* f, int len, UChar* s)
 {
   fputs(":", f);
@@ -5846,8 +6254,16 @@ p_len_string(FILE* f, LengthType len, int mb_len, UChar* s)
   while (x-- > 0) { fputc(*s++, f); }
 }
 
+static void
+p_rel_addr(FILE* f, RelAddrType rel_addr, UChar* p, UChar* start)
+{
+  RelAddrType curr = (RelAddrType )(p - start);
+
+  fprintf(f, "{%d/%d}", rel_addr, curr + rel_addr);
+}
+
 extern void
-onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
+onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp, UChar* start,
                               OnigEncoding enc)
 {
   int i, n, arg_type;
@@ -5858,7 +6274,7 @@ onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
   OnigCodePoint code;
   UChar *q;
 
-  fprintf(f, "[%s", op2name(*bp));
+  fprintf(f, "%s", op2name(*bp));
   arg_type = op2arg_type(*bp);
   if (arg_type != ARG_SPECIAL) {
     bp++;
@@ -5867,11 +6283,12 @@ onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
       break;
     case ARG_RELADDR:
       GET_RELADDR_INC(addr, bp);
-      fprintf(f, ":(%d)", addr);
+      fputc(':', f);
+      p_rel_addr(f, addr, bp, start);
       break;
     case ARG_ABSADDR:
       GET_ABSADDR_INC(addr, bp);
-      fprintf(f, ":(%d)", addr);
+      fprintf(f, ":{/%d}", addr);
       break;
     case ARG_LENGTH:
       GET_LENGTH_INC(len, bp);
@@ -6056,7 +6473,8 @@ onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
     case OP_PUSH_IF_PEEK_NEXT:
       addr = *((RelAddrType* )bp);
       bp += SIZE_RELADDR;
-      fprintf(f, ":(%d)", addr);
+      fputc(':', f);
+      p_rel_addr(f, addr, bp, start);
       p_string(f, 1, bp);
       bp += 1;
       break;
@@ -6069,7 +6487,8 @@ onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
     case OP_PUSH_LOOK_BEHIND_NOT:
       GET_RELADDR_INC(addr, bp);
       GET_LENGTH_INC(len, bp);
-      fprintf(f, ":%d:(%d)", len, addr);
+      fprintf(f, ":%d:", len);
+      p_rel_addr(f, addr, bp, start);
       break;
 
     case OP_STATE_CHECK_PUSH:
@@ -6078,7 +6497,8 @@ onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
       bp += SIZE_STATE_CHECK_NUM;
       addr = *((RelAddrType* )bp);
       bp += SIZE_RELADDR;
-      fprintf(f, ":%d:(%d)", scn, addr);
+      fprintf(f, ":%d:", scn);
+      p_rel_addr(f, addr, bp, start);
       break;
 
     default:
@@ -6086,40 +6506,50 @@ onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar** nextp,
 	      *--bp);
     }
   }
-  fputs("]", f);
   if (nextp) *nextp = bp;
 }
+#endif /* ONIG_DEBUG */
 
+#ifdef ONIG_DEBUG_COMPILE
 static void
 print_compiled_byte_code_list(FILE* f, regex_t* reg)
 {
-  int ncode;
-  UChar* bp = reg->p;
-  UChar* end = reg->p + reg->used;
+  UChar* bp;
+  UChar* start = reg->p;
+  UChar* end   = reg->p + reg->used;
 
-  fprintf(f, "code length: %d\n", reg->used);
+  fprintf(f, "bt_mem_start: 0x%x, bt_mem_end: 0x%x\n",
+          reg->bt_mem_start, reg->bt_mem_end);
+  fprintf(f, "code-length: %d\n", reg->used);
 
-  ncode = 0;
+  bp = start;
   while (bp < end) {
-    ncode++;
-    if (bp > reg->p) {
-      if (ncode % 5 == 0)
-        fprintf(f, "\n");
-      else
-        fputs(" ", f);
-    }
-    onig_print_compiled_byte_code(f, bp, &bp, reg->enc);
-  }
+    int pos = bp - start;
 
+    fprintf(f, "%4d: ", pos);
+    onig_print_compiled_byte_code(f, bp, &bp, start, reg->enc);
+    fprintf(f, "\n");
+  }
   fprintf(f, "\n");
 }
+#endif
+
+#ifdef ONIG_DEBUG_PARSE_TREE
+
+static void
+Indent(FILE* f, int indent)
+{
+  int i;
+  for (i = 0; i < indent; i++) putc(' ', f);
+}
 
 static void
 print_indent_tree(FILE* f, Node* node, int indent)
 {
-  int i, type;
-  int add = 3;
+  int i;
+  NodeType type;
   UChar* p;
+  int add = 3;
 
   Indent(f, indent);
   if (IS_NULL(node)) {
@@ -6127,29 +6557,29 @@ print_indent_tree(FILE* f, Node* node, int indent)
     exit (0);
   }
 
-  type = NTYPE(node);
+  type = NODE_TYPE(node);
   switch (type) {
-  case NT_LIST:
-  case NT_ALT:
-    if (NTYPE(node) == NT_LIST)
+  case NODE_LIST:
+  case NODE_ALT:
+    if (type == NODE_LIST)
       fprintf(f, "<list:%p>\n", node);
     else
       fprintf(f, "<alt:%p>\n", node);
 
-    print_indent_tree(f, NCAR(node), indent + add);
-    while (IS_NOT_NULL(node = NCDR(node))) {
-      if (NTYPE(node) != type) {
-        fprintf(f, "ERROR: list/alt right is not a cons. %d\n", NTYPE(node));
+    print_indent_tree(f, NODE_CAR(node), indent + add);
+    while (IS_NOT_NULL(node = NODE_CDR(node))) {
+      if (NODE_TYPE(node) != type) {
+        fprintf(f, "ERROR: list/alt right is not a cons. %d\n", NODE_TYPE(node));
         exit(0);
       }
-      print_indent_tree(f, NCAR(node), indent + add);
+      print_indent_tree(f, NODE_CAR(node), indent + add);
     }
     break;
 
-  case NT_STR:
+  case NODE_STR:
     fprintf(f, "<string%s:%p>",
 	    (NSTRING_IS_RAW(node) ? "-raw" : ""), node);
-    for (p = NSTR(node)->s; p < NSTR(node)->end; p++) {
+    for (p = STR_(node)->s; p < STR_(node)->end; p++) {
       if (*p >= 0x20 && *p < 0x7f)
         fputc(*p, f);
       else {
@@ -6158,11 +6588,11 @@ print_indent_tree(FILE* f, Node* node, int indent)
     }
     break;
 
-  case NT_CCLASS:
+  case NODE_CCLASS:
     fprintf(f, "<cclass:%p>", node);
-    if (IS_NCCLASS_NOT(NCCLASS(node))) fputs(" not", f);
-    if (NCCLASS(node)->mbuf) {
-      BBuf* bbuf = NCCLASS(node)->mbuf;
+    if (IS_NCCLASS_NOT(CCLASS_(node))) fputs(" not", f);
+    if (CCLASS_(node)->mbuf) {
+      BBuf* bbuf = CCLASS_(node)->mbuf;
       for (i = 0; i < bbuf->used; i++) {
         if (i > 0) fprintf(f, ",");
         fprintf(f, "%0x", bbuf->p[i]);
@@ -6170,11 +6600,15 @@ print_indent_tree(FILE* f, Node* node, int indent)
     }
     break;
 
-  case NT_CTYPE:
+  case NODE_CTYPE:
     fprintf(f, "<ctype:%p> ", node);
-    switch (NCTYPE(node)->ctype) {
+    switch (CTYPE_(node)->ctype) {
+    case CTYPE_ANYCHAR:
+      fprintf(f, "<anychar:%p>", node);
+      break;
+
     case ONIGENC_CTYPE_WORD:
-      if (NCTYPE(node)->not != 0)
+      if (CTYPE_(node)->not != 0)
         fputs("not word",       f);
       else
         fputs("word",           f);
@@ -6186,13 +6620,9 @@ print_indent_tree(FILE* f, Node* node, int indent)
     }
     break;
 
-  case NT_CANY:
-    fprintf(f, "<anychar:%p>", node);
-    break;
-
-  case NT_ANCHOR:
+  case NODE_ANCHOR:
     fprintf(f, "<anchor:%p> ", node);
-    switch (NANCHOR(node)->type) {
+    switch (ANCHOR_(node)->type) {
     case ANCHOR_BEGIN_BUF:      fputs("begin buf",      f); break;
     case ANCHOR_END_BUF:        fputs("end buf",        f); break;
     case ANCHOR_BEGIN_LINE:     fputs("begin line",     f); break;
@@ -6208,19 +6638,19 @@ print_indent_tree(FILE* f, Node* node, int indent)
 #endif
     case ANCHOR_PREC_READ:
       fprintf(f, "prec read\n");
-      print_indent_tree(f, NANCHOR(node)->target, indent + add);
+      print_indent_tree(f, NODE_BODY(node), indent + add);
       break;
     case ANCHOR_PREC_READ_NOT:
       fprintf(f, "prec read not\n");
-      print_indent_tree(f, NANCHOR(node)->target, indent + add);
+      print_indent_tree(f, NODE_BODY(node), indent + add);
       break;
     case ANCHOR_LOOK_BEHIND:
       fprintf(f, "look behind\n");
-      print_indent_tree(f, NANCHOR(node)->target, indent + add);
+      print_indent_tree(f, NODE_BODY(node), indent + add);
       break;
     case ANCHOR_LOOK_BEHIND_NOT:
       fprintf(f, "look behind not\n");
-      print_indent_tree(f, NANCHOR(node)->target, indent + add);
+      print_indent_tree(f, NODE_BODY(node), indent + add);
       break;
 
     default:
@@ -6229,10 +6659,10 @@ print_indent_tree(FILE* f, Node* node, int indent)
     }
     break;
 
-  case NT_BREF:
+  case NODE_BREF:
     {
       int* p;
-      BRefNode* br = NBREF(node);
+      BRefNode* br = BREF_(node);
       p = BACKREFS_P(br);
       fprintf(f, "<backref:%p>", node);
       for (i = 0; i < br->back_num; i++) {
@@ -6243,32 +6673,32 @@ print_indent_tree(FILE* f, Node* node, int indent)
     break;
 
 #ifdef USE_SUBEXP_CALL
-  case NT_CALL:
+  case NODE_CALL:
     {
-      CallNode* cn = NCALL(node);
+      CallNode* cn = CALL_(node);
       fprintf(f, "<call:%p>", node);
       p_string(f, cn->name_end - cn->name, cn->name);
     }
     break;
 #endif
 
-  case NT_QTFR:
+  case NODE_QUANT:
     fprintf(f, "<quantifier:%p>{%d,%d}%s\n", node,
-	    NQTFR(node)->lower, NQTFR(node)->upper,
-	    (NQTFR(node)->greedy ? "" : "?"));
-    print_indent_tree(f, NQTFR(node)->target, indent + add);
+	    QUANT_(node)->lower, QUANT_(node)->upper,
+	    (QUANT_(node)->greedy ? "" : "?"));
+    print_indent_tree(f, NODE_BODY(node), indent + add);
     break;
 
-  case NT_ENCLOSE:
-    fprintf(f, "<enclose:%p> ", node);
-    switch (NENCLOSE(node)->type) {
-    case ENCLOSE_OPTION:
-      fprintf(f, "option:%d", NENCLOSE(node)->option);
+  case NODE_ENCLOSURE:
+    fprintf(f, "<enclosure:%p> ", node);
+    switch (ENCLOSURE_(node)->type) {
+    case ENCLOSURE_OPTION:
+      fprintf(f, "option:%d", ENCLOSURE_(node)->option);
       break;
-    case ENCLOSE_MEMORY:
-      fprintf(f, "memory:%d", NENCLOSE(node)->regnum);
+    case ENCLOSURE_MEMORY:
+      fprintf(f, "memory:%d", ENCLOSURE_(node)->regnum);
       break;
-    case ENCLOSE_STOP_BACKTRACK:
+    case ENCLOSURE_STOP_BACKTRACK:
       fprintf(f, "stop-bt");
       break;
 
@@ -6276,22 +6706,20 @@ print_indent_tree(FILE* f, Node* node, int indent)
       break;
     }
     fprintf(f, "\n");
-    print_indent_tree(f, NENCLOSE(node)->target, indent + add);
+    print_indent_tree(f, NODE_BODY(node), indent + add);
     break;
 
   default:
-    fprintf(f, "print_indent_tree: undefined node type %d\n", NTYPE(node));
+    fprintf(f, "print_indent_tree: undefined node type %d\n", NODE_TYPE(node));
     break;
   }
 
-  if (type != NT_LIST && type != NT_ALT && type != NT_QTFR &&
-      type != NT_ENCLOSE)
+  if (type != NODE_LIST && type != NODE_ALT && type != NODE_QUANT &&
+      type != NODE_ENCLOSURE)
     fprintf(f, "\n");
   fflush(f);
 }
-#endif /* ONIG_DEBUG */
 
-#ifdef ONIG_DEBUG_PARSE_TREE
 static void
 print_tree(FILE* f, Node* node)
 {
diff --git a/src/regenc.h b/src/regenc.h
index e119dab..897c704 100644
--- a/src/regenc.h
+++ b/src/regenc.h
@@ -4,7 +4,7 @@
   regenc.h -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2016  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2017  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -154,7 +154,7 @@ ONIG_EXTERN struct PropertyNameCtype* sjis_lookup_property_name P_((register con
 /* in enc/unicode.c */
 ONIG_EXTERN int onigenc_unicode_is_code_ctype P_((OnigCodePoint code, unsigned int ctype));
 ONIG_EXTERN int onigenc_utf16_32_get_ctype_code_range P_((OnigCtype ctype, OnigCodePoint *sb_out, const OnigCodePoint* ranges[]));
-ONIG_EXTERN int onigenc_unicode_ctype_code_range P_((int ctype, const OnigCodePoint* ranges[]));
+ONIG_EXTERN int onigenc_unicode_ctype_code_range P_((OnigCtype ctype, const OnigCodePoint* ranges[]));
 ONIG_EXTERN int onigenc_unicode_get_case_fold_codes_by_str P_((OnigEncoding enc, OnigCaseFoldType flag, const OnigUChar* p, const OnigUChar* end, OnigCaseFoldCodeItem items[]));
 ONIG_EXTERN int onigenc_unicode_mbc_case_fold P_((OnigEncoding enc, OnigCaseFoldType flag, const UChar** pp, const UChar* end, UChar* fold));
 ONIG_EXTERN int onigenc_unicode_apply_all_case_fold P_((OnigCaseFoldType flag, OnigApplyAllCaseFoldFunc f, void* arg));
diff --git a/src/regerror.c b/src/regerror.c
index ee35b36..0285272 100644
--- a/src/regerror.c
+++ b/src/regerror.c
@@ -2,7 +2,7 @@
   regerror.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2007  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2017  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -211,24 +211,24 @@ static int to_ascii(OnigEncoding enc, UChar *s, UChar *end,
     while (p < end) {
       code = ONIGENC_MBC_TO_CODE(enc, p, end);
       if (code >= 0x80) {
-	if (code > 0xffff && len + 10 <= buf_size) {
-	  sprint_byte_with_x((char*)(&(buf[len])), (unsigned int)(code >> 24));
-	  sprint_byte((char*)(&(buf[len+4])),      (unsigned int)(code >> 16));
-	  sprint_byte((char*)(&(buf[len+6])),      (unsigned int)(code >>  8));
-	  sprint_byte((char*)(&(buf[len+8])),      (unsigned int)code);
-	  len += 10;
-	}
-	else if (len + 6 <= buf_size) {
-	  sprint_byte_with_x((char*)(&(buf[len])), (unsigned int)(code >> 8));
-	  sprint_byte((char*)(&(buf[len+4])),      (unsigned int)code);
-	  len += 6;
-	}
-	else {
-	  break;
-	}
+        if (code > 0xffff && len + 10 <= buf_size) {
+          sprint_byte_with_x((char*)(&(buf[len])), (unsigned int)(code >> 24));
+          sprint_byte((char*)(&(buf[len+4])),      (unsigned int)(code >> 16));
+          sprint_byte((char*)(&(buf[len+6])),      (unsigned int)(code >>  8));
+          sprint_byte((char*)(&(buf[len+8])),      (unsigned int)code);
+          len += 10;
+        }
+        else if (len + 6 <= buf_size) {
+          sprint_byte_with_x((char*)(&(buf[len])), (unsigned int)(code >> 8));
+          sprint_byte((char*)(&(buf[len+4])),      (unsigned int)code);
+          len += 6;
+        }
+        else {
+          break;
+        }
       }
       else {
-	buf[len++] = (UChar )code;
+        buf[len++] = (UChar )code;
       }
 
       p += enclen(enc, p);
@@ -278,27 +278,27 @@ onig_error_code_to_str(s, code, va_alist)
   case ONIGERR_INVALID_CHAR_PROPERTY_NAME:
     einfo = va_arg(vargs, OnigErrorInfo*);
     len = to_ascii(einfo->enc, einfo->par, einfo->par_end,
-		   parbuf, MAX_ERROR_PAR_LEN - 3, &is_over);
+                   parbuf, MAX_ERROR_PAR_LEN - 3, &is_over);
     q = onig_error_code_to_format(code);
     p = s;
     while (*q != '\0') {
       if (*q == '%') {
-	q++;
-	if (*q == 'n') { /* '%n': name */
-	  xmemcpy(p, parbuf, len);
-	  p += len;
-	  if (is_over != 0) {
-	    xmemcpy(p, "...", 3);
-	    p += 3;
-	  }
-	  q++;
-	}
-	else
-	  goto normal_char;
+        q++;
+        if (*q == 'n') { /* '%n': name */
+          xmemcpy(p, parbuf, len);
+          p += len;
+          if (is_over != 0) {
+            xmemcpy(p, "...", 3);
+            p += 3;
+          }
+          q++;
+        }
+        else
+          goto normal_char;
       }
       else {
       normal_char:
-	*p++ = *q++;
+        *p++ = *q++;
       }
     }
     *p = '\0';
@@ -359,7 +359,7 @@ onig_snprintf_with_pattern(buf, bufsize, enc, pat, pat_end, fmt, va_alist)
           int blen;
 
           while (len-- > 0) {
-	    sprint_byte_with_x((char* )bs, (unsigned int )(*p++));
+            sprint_byte_with_x((char* )bs, (unsigned int )(*p++));
             blen = onigenc_str_bytelen_null(ONIG_ENCODING_ASCII, bs);
             bp = bs;
             while (blen-- > 0) *s++ = *bp++;
@@ -367,23 +367,23 @@ onig_snprintf_with_pattern(buf, bufsize, enc, pat, pat_end, fmt, va_alist)
         }
       }
       else if (*p == '\\') {
-	*s++ = *p++;
-	len = enclen(enc, p);
-	while (len-- > 0) *s++ = *p++;
+        *s++ = *p++;
+        len = enclen(enc, p);
+        while (len-- > 0) *s++ = *p++;
       }
       else if (*p == '/') {
-	*s++ = (unsigned char )'\\';
-	*s++ = *p++;
+        *s++ = (unsigned char )'\\';
+        *s++ = *p++;
       }
       else if (!ONIGENC_IS_CODE_PRINT(enc, *p) &&
-	       !ONIGENC_IS_CODE_SPACE(enc, *p)) {
-	sprint_byte_with_x((char* )bs, (unsigned int )(*p++));
-	len = onigenc_str_bytelen_null(ONIG_ENCODING_ASCII, bs);
+               !ONIGENC_IS_CODE_SPACE(enc, *p)) {
+        sprint_byte_with_x((char* )bs, (unsigned int )(*p++));
+        len = onigenc_str_bytelen_null(ONIG_ENCODING_ASCII, bs);
         bp = bs;
-	while (len-- > 0) *s++ = *bp++;
+        while (len-- > 0) *s++ = *bp++;
       }
       else {
-	*s++ = *p++;
+        *s++ = *p++;
       }
     }
 
diff --git a/src/regexec.c b/src/regexec.c
index c0626ef..f66da1f 100644
--- a/src/regexec.c
+++ b/src/regexec.c
@@ -240,6 +240,7 @@ onig_region_new(void)
   OnigRegion* r;
 
   r = (OnigRegion* )xmalloc(sizeof(OnigRegion));
+  CHECK_NULL_RETURN(r);
   onig_region_init(r);
   return r;
 }
@@ -247,7 +248,7 @@ onig_region_new(void)
 extern void
 onig_region_free(OnigRegion* r, int free_self)
 {
-  if (r) {
+  if (r != 0) {
     if (r->allocated > 0) {
       if (r->beg) xfree(r->beg);
       if (r->end) xfree(r->end);
@@ -271,13 +272,17 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
   if (to->allocated == 0) {
     if (from->num_regs > 0) {
       to->beg = (int* )xmalloc(RREGC_SIZE);
+      if (IS_NULL(to->beg)) return;
       to->end = (int* )xmalloc(RREGC_SIZE);
+      if (IS_NULL(to->end)) return;
       to->allocated = from->num_regs;
     }
   }
   else if (to->allocated < from->num_regs) {
     to->beg = (int* )xrealloc(to->beg, RREGC_SIZE);
+    if (IS_NULL(to->beg)) return;
     to->end = (int* )xrealloc(to->end, RREGC_SIZE);
+    if (IS_NULL(to->end)) return;
     to->allocated = from->num_regs;
   }
 
@@ -311,8 +316,8 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
 #define STK_REPEAT_INC             0x0300
 #define STK_STATE_CHECK_MARK       0x1000
 /* avoided by normal-POP */
-#define STK_NULL_CHECK_START       0x3000
-#define STK_NULL_CHECK_END         0x5000  /* for recursive call */
+#define STK_EMPTY_CHECK_START      0x3000
+#define STK_EMPTY_CHECK_END        0x5000  /* for recursive call */
 #define STK_MEM_END_MARK           0x8400
 #define STK_POS                    0x0500  /* used when POP-POS */
 #define STK_STOP_BT                0x0600  /* mark for "(?>...)" */
@@ -333,7 +338,7 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
   (msa).region   = (arg_region);\
   (msa).start    = (arg_start);\
   (msa).best_len = ONIG_MISMATCH;\
-  (msa).ptr_num  = (reg)->num_repeat + (reg)->num_mem * 2;\
+  (msa).ptr_num  = (reg)->num_repeat + ((reg)->num_mem + 1) * 2; \
 } while(0)
 #else
 #define MATCH_ARG_INIT(msa, reg, arg_option, arg_region, arg_start) do {\
@@ -341,7 +346,7 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
   (msa).options  = (arg_option);\
   (msa).region   = (arg_region);\
   (msa).start    = (arg_start);\
-  (msa).ptr_num  = (reg)->num_repeat + (reg)->num_mem * 2;\
+  (msa).ptr_num  = (reg)->num_repeat + ((reg)->num_mem + 1) * 2; \
 } while(0)
 #endif
 
@@ -400,6 +405,7 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
     is_alloca  = 0;\
     alloc_base = (char* )xmalloc(sizeof(OnigStackIndex) * msa->ptr_num\
                   + sizeof(OnigStackType) * (stack_num));\
+    CHECK_NULL_RETURN_MEMERR(alloc_base);\
     stk_base   = (OnigStackType* )(alloc_base\
                  + (sizeof(OnigStackIndex) * msa->ptr_num));\
     stk        = stk_base;\
@@ -409,6 +415,7 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
     is_alloca  = 1;\
     alloc_base = (char* )xalloca(sizeof(OnigStackIndex) * msa->ptr_num\
                  + sizeof(OnigStackType) * (stack_num));\
+    CHECK_NULL_RETURN_MEMERR(alloc_base);\
     stk_base   = (OnigStackType* )(alloc_base\
                  + (sizeof(OnigStackIndex) * msa->ptr_num));\
     stk        = stk_base;\
@@ -423,6 +430,7 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
     size_t size = sizeof(OnigStackIndex) * msa->ptr_num \
                 + sizeof(OnigStackType) * msa->stack_n;\
     msa->stack_p = xmalloc(size);\
+    CHECK_NULL_RETURN_MEMERR(msa->stack_p);\
     xmemcpy(msa->stack_p, alloc_base, size);\
   }\
   else {\
@@ -431,11 +439,9 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
 } while(0)
 
 #define UPDATE_FOR_STACK_REALLOC do{\
-  repeat_stk = (OnigStackIndex* )alloc_base;\
+  repeat_stk    = (OnigStackIndex* )alloc_base;\
   mem_start_stk = (OnigStackIndex* )(repeat_stk + reg->num_repeat);\
-  mem_end_stk   = mem_start_stk + num_mem;\
-  mem_start_stk--; /* for index start from 1 */\
-  mem_end_stk--;   /* for index start from 1 */\
+  mem_end_stk   = mem_start_stk + num_mem + 1;\
 } while(0)
 
 static unsigned int MatchStackLimitSize = DEFAULT_MATCH_STACK_LIMIT_SIZE;
@@ -533,7 +539,7 @@ stack_double(int is_alloca, char** arg_alloc_base,
 #define STATE_CHECK_POS(s,snum) \
   (((s) - str) * num_comb_exp_check + ((snum) - 1))
 #define STATE_CHECK_VAL(v,snum) do {\
-  if (state_check_buff != NULL) {\
+  if (IS_NOT_NULL(state_check_buff)) {\
     int x = STATE_CHECK_POS(s,snum);\
     (v) = state_check_buff[x/8] & (1<<(x%8));\
   }\
@@ -570,12 +576,12 @@ stack_double(int is_alloca, char** arg_alloc_base,
   stk->u.state.pcode     = (pat);\
   stk->u.state.pstr      = (s);\
   stk->u.state.pstr_prev = (sprev);\
-  stk->u.state.state_check = ((state_check_buff != NULL) ? (snum) : 0);\
+  stk->u.state.state_check = (IS_NOT_NULL(state_check_buff) ? (snum) : 0);\
   STACK_INC;\
 } while(0)
 
 #define STACK_PUSH_STATE_CHECK(s,snum) do {\
-  if (state_check_buff != NULL) {\
+  if (IS_NOT_NULL(state_check_buff)) {   \
     STACK_ENSURE(1);\
     stk->type = STK_STATE_CHECK_MARK;\
     stk->u.state.pstr = (s);\
@@ -691,18 +697,18 @@ stack_double(int is_alloca, char** arg_alloc_base,
   }\
 } while(0)
 
-#define STACK_PUSH_NULL_CHECK_START(cnum, s) do {\
+#define STACK_PUSH_EMPTY_CHECK_START(cnum, s) do {\
   STACK_ENSURE(1);\
-  stk->type = STK_NULL_CHECK_START;\
-  stk->u.null_check.num  = (cnum);\
-  stk->u.null_check.pstr = (s);\
+  stk->type = STK_EMPTY_CHECK_START;\
+  stk->u.empty_check.num  = (cnum);\
+  stk->u.empty_check.pstr = (s);\
   STACK_INC;\
 } while(0)
 
-#define STACK_PUSH_NULL_CHECK_END(cnum) do {\
+#define STACK_PUSH_EMPTY_CHECK_END(cnum) do {\
   STACK_ENSURE(1);\
-  stk->type = STK_NULL_CHECK_END;\
-  stk->u.null_check.num  = (cnum);\
+  stk->type = STK_EMPTY_CHECK_END;\
+  stk->u.empty_check.num  = (cnum);\
   STACK_INC;\
 } while(0)
 
@@ -849,49 +855,29 @@ stack_double(int is_alloca, char** arg_alloc_base,
   }\
 } while(0)
 
-#define STACK_NULL_CHECK(isnull,id,s) do {\
+#define STACK_EMPTY_CHECK(isnull,id,s) do {\
   OnigStackType* k = stk;\
   while (1) {\
     k--;\
-    STACK_BASE_CHECK(k, "STACK_NULL_CHECK"); \
-    if (k->type == STK_NULL_CHECK_START) {\
-      if (k->u.null_check.num == (id)) {\
-        (isnull) = (k->u.null_check.pstr == (s));\
+    STACK_BASE_CHECK(k, "STACK_EMPTY_CHECK"); \
+    if (k->type == STK_EMPTY_CHECK_START) {\
+      if (k->u.empty_check.num == (id)) {\
+        (isnull) = (k->u.empty_check.pstr == (s));\
         break;\
       }\
     }\
   }\
 } while(0)
 
-#define STACK_NULL_CHECK_REC(isnull,id,s) do {\
-  int level = 0;\
+#ifdef USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT
+#define STACK_EMPTY_CHECK_MEMST(isnull,id,s,reg) do {\
   OnigStackType* k = stk;\
   while (1) {\
     k--;\
-    STACK_BASE_CHECK(k, "STACK_NULL_CHECK_REC"); \
-    if (k->type == STK_NULL_CHECK_START) {\
-      if (k->u.null_check.num == (id)) {\
-        if (level == 0) {\
-          (isnull) = (k->u.null_check.pstr == (s));\
-          break;\
-        }\
-        else level--;\
-      }\
-    }\
-    else if (k->type == STK_NULL_CHECK_END) {\
-      level++;\
-    }\
-  }\
-} while(0)
-
-#define STACK_NULL_CHECK_MEMST(isnull,id,s,reg) do {\
-  OnigStackType* k = stk;\
-  while (1) {\
-    k--;\
-    STACK_BASE_CHECK(k, "STACK_NULL_CHECK_MEMST"); \
-    if (k->type == STK_NULL_CHECK_START) {\
-      if (k->u.null_check.num == (id)) {\
-        if (k->u.null_check.pstr != (s)) {\
+    STACK_BASE_CHECK(k, "STACK_EMPTY_CHECK_MEMST"); \
+    if (k->type == STK_EMPTY_CHECK_START) {\
+      if (k->u.empty_check.num == (id)) {\
+        if (k->u.empty_check.pstr != (s)) {\
           (isnull) = 0;\
           break;\
         }\
@@ -903,10 +889,11 @@ stack_double(int is_alloca, char** arg_alloc_base,
               if (k->u.mem.end == INVALID_STACK_INDEX) {\
                 (isnull) = 0; break;\
               }\
-              if (BIT_STATUS_AT(reg->bt_mem_end, k->u.mem.num))\
+              if (MEM_STATUS_AT(reg->bt_mem_end, k->u.mem.num))\
                 endp = STACK_AT(k->u.mem.end)->u.mem.pstr;\
               else\
                 endp = (UChar* )k->u.mem.end;\
+              /*fprintf(stderr, "num: %d, pstr: %p, endp: %p\n", k->u.mem.num, STACK_AT(k->u.mem.start)->u.mem.pstr, endp);*/ \
               if (STACK_AT(k->u.mem.start)->u.mem.pstr != endp) {\
                 (isnull) = 0; break;\
               }\
@@ -916,23 +903,23 @@ stack_double(int is_alloca, char** arg_alloc_base,
             }\
             k++;\
           }\
-  	  break;\
+          break;\
         }\
       }\
     }\
   }\
 } while(0)
 
-#define STACK_NULL_CHECK_MEMST_REC(isnull,id,s,reg) do {\
+#define STACK_EMPTY_CHECK_MEMST_REC(isnull,id,s,reg) do {\
   int level = 0;\
   OnigStackType* k = stk;\
   while (1) {\
     k--;\
-    STACK_BASE_CHECK(k, "STACK_NULL_CHECK_MEMST_REC"); \
-    if (k->type == STK_NULL_CHECK_START) {\
-      if (k->u.null_check.num == (id)) {\
+    STACK_BASE_CHECK(k, "STACK_EMPTY_CHECK_MEMST_REC"); \
+    if (k->type == STK_EMPTY_CHECK_START) {\
+      if (k->u.empty_check.num == (id)) {\
         if (level == 0) {\
-          if (k->u.null_check.pstr != (s)) {\
+          if (k->u.empty_check.pstr != (s)) {\
             (isnull) = 0;\
             break;\
           }\
@@ -944,7 +931,7 @@ stack_double(int is_alloca, char** arg_alloc_base,
                 if (k->u.mem.end == INVALID_STACK_INDEX) {\
                   (isnull) = 0; break;\
                 }\
-                if (BIT_STATUS_AT(reg->bt_mem_end, k->u.mem.num))\
+                if (MEM_STATUS_AT(reg->bt_mem_end, k->u.mem.num))\
                   endp = STACK_AT(k->u.mem.end)->u.mem.pstr;\
                 else\
                   endp = (UChar* )k->u.mem.end;\
@@ -957,7 +944,7 @@ stack_double(int is_alloca, char** arg_alloc_base,
               }\
               k++;\
             }\
-  	    break;\
+            break;\
           }\
         }\
         else {\
@@ -965,11 +952,33 @@ stack_double(int is_alloca, char** arg_alloc_base,
         }\
       }\
     }\
-    else if (k->type == STK_NULL_CHECK_END) {\
-      if (k->u.null_check.num == (id)) level++;\
+    else if (k->type == STK_EMPTY_CHECK_END) {\
+      if (k->u.empty_check.num == (id)) level++;\
+    }\
+  }\
+} while(0)
+#else
+#define STACK_EMPTY_CHECK_REC(isnull,id,s) do {\
+  int level = 0;\
+  OnigStackType* k = stk;\
+  while (1) {\
+    k--;\
+    STACK_BASE_CHECK(k, "STACK_EMPTY_CHECK_REC"); \
+    if (k->type == STK_EMPTY_CHECK_START) {\
+      if (k->u.empty_check.num == (id)) {\
+        if (level == 0) {\
+          (isnull) = (k->u.empty_check.pstr == (s));\
+          break;\
+        }\
+      }\
+      level--;\
+    }\
+    else if (k->type == STK_EMPTY_CHECK_END) {\
+      level++;\
     }\
   }\
 } while(0)
+#endif /* USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT */
 
 #define STACK_GET_REPEAT(id, k) do {\
   int level = 0;\
@@ -1091,7 +1100,7 @@ make_capture_history_tree(OnigCaptureTreeNode* node, OnigStackType** kp,
     if (k->type == STK_MEM_START) {
       n = k->u.mem.num;
       if (n <= ONIG_MAX_CAPTURE_HISTORY_GROUP &&
-          BIT_STATUS_AT(reg->capture_history, n) != 0) {
+          MEM_STATUS_AT(reg->capture_history, n) != 0) {
         child = history_node_new();
         CHECK_NULL_RETURN_MEMERR(child);
         child->group = n;
@@ -1156,7 +1165,7 @@ static int backref_match_at_nested_level(regex_t* reg
       if (k->type == STK_MEM_START) {
         if (mem_is_in_memp(k->u.mem.num, mem_num, memp)) {
           pstart = k->u.mem.pstr;
-          if (pend != NULL_UCHARP) {
+          if (IS_NOT_NULL(pend)) {
             if (pend - pstart > send - *s) return 0; /* or goto next_mem; */
             p  = pstart;
             ss = *s;
@@ -1329,8 +1338,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   }
 
 #ifdef ONIG_DEBUG_MATCH
-  fprintf(stderr, "match_at: str: %d, end: %d, start: %d, sprev: %d\n",
-	  (int )str, (int )end, (int )sstart, (int )sprev);
+  fprintf(stderr, "match_at: str: %p, end: %p, start: %p, sprev: %p\n",
+          str, end, sstart, sprev);
   fprintf(stderr, "size: %d, start offset: %d\n",
 	  (int )(end - str), (int )(sstart - str));
 #endif
@@ -1341,9 +1350,14 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   while (1) {
 #ifdef ONIG_DEBUG_MATCH
     {
+      static unsigned int counter = 1;
+
       UChar *q, *bp, buf[50];
       int len;
-      fprintf(stderr, "%4d> \"", (int )(s - str));
+      fprintf(stderr, "%7u: %7ld: %4d> \"",
+              counter, GET_STACK_INDEX(stk), (int )(s - str));
+      counter++;
+
       bp = buf;
       for (i = 0, q = s; i < 7 && q < end; i++) {
         len = enclen(encode, q);
@@ -1353,8 +1367,10 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       else         { xmemcpy(bp, "\"",    1); bp += 1; }
       *bp = 0;
       fputs((char* )buf, stderr);
+
       for (i = 0; i < 20 - (bp - buf); i++) fputc(' ', stderr);
-      onig_print_compiled_byte_code(stderr, p, NULL, encode);
+      fprintf(stderr, "%4d: ", (int )(p - reg->p));
+      onig_print_compiled_byte_code(stderr, p, NULL, reg->p, encode);
       fprintf(stderr, "\n");
     }
 #endif
@@ -1386,12 +1402,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
             rmt[0].rm_eo = s      - str;
             for (i = 1; i <= num_mem; i++) {
               if (mem_end_stk[i] != INVALID_STACK_INDEX) {
-                if (BIT_STATUS_AT(reg->bt_mem_start, i))
+                if (MEM_STATUS_AT(reg->bt_mem_start, i))
                   rmt[i].rm_so = STACK_AT(mem_start_stk[i])->u.mem.pstr - str;
                 else
                   rmt[i].rm_so = (UChar* )((void* )(mem_start_stk[i])) - str;
 
-                rmt[i].rm_eo = (BIT_STATUS_AT(reg->bt_mem_end, i)
+                rmt[i].rm_eo = (MEM_STATUS_AT(reg->bt_mem_end, i)
                                 ? STACK_AT(mem_end_stk[i])->u.mem.pstr
                                 : (UChar* )((void* )mem_end_stk[i])) - str;
               }
@@ -1406,12 +1422,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
             region->end[0] = s      - str;
             for (i = 1; i <= num_mem; i++) {
               if (mem_end_stk[i] != INVALID_STACK_INDEX) {
-                if (BIT_STATUS_AT(reg->bt_mem_start, i))
+                if (MEM_STATUS_AT(reg->bt_mem_start, i))
                   region->beg[i] = STACK_AT(mem_start_stk[i])->u.mem.pstr - str;
                 else
                   region->beg[i] = (UChar* )((void* )mem_start_stk[i]) - str;
 
-                region->end[i] = (BIT_STATUS_AT(reg->bt_mem_end, i)
+                region->end[i] = (MEM_STATUS_AT(reg->bt_mem_end, i)
                                   ? STACK_AT(mem_end_stk[i])->u.mem.pstr
                                   : (UChar* )((void* )mem_end_stk[i])) - str;
               }
@@ -2156,7 +2172,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       mem_end_stk[mem] = (OnigStackIndex )((void* )s);
       STACK_GET_MEM_START(mem, stkp);
 
-      if (BIT_STATUS_AT(reg->bt_mem_start, mem))
+      if (MEM_STATUS_AT(reg->bt_mem_start, mem))
         mem_start_stk[mem] = GET_STACK_INDEX(stkp);
       else
         mem_start_stk[mem] = (OnigStackIndex )((void* )stkp->u.mem.pstr);
@@ -2190,12 +2206,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         if (mem_end_stk[mem]   == INVALID_STACK_INDEX) goto fail;
         if (mem_start_stk[mem] == INVALID_STACK_INDEX) goto fail;
 
-        if (BIT_STATUS_AT(reg->bt_mem_start, mem))
+        if (MEM_STATUS_AT(reg->bt_mem_start, mem))
           pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
         else
           pstart = (UChar* )((void* )mem_start_stk[mem]);
 
-        pend = (BIT_STATUS_AT(reg->bt_mem_end, mem)
+        pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
                 ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
                 : (UChar* )((void* )mem_end_stk[mem]));
         n = pend - pstart;
@@ -2222,12 +2238,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         if (mem_end_stk[mem]   == INVALID_STACK_INDEX) goto fail;
         if (mem_start_stk[mem] == INVALID_STACK_INDEX) goto fail;
 
-        if (BIT_STATUS_AT(reg->bt_mem_start, mem))
+        if (MEM_STATUS_AT(reg->bt_mem_start, mem))
           pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
         else
           pstart = (UChar* )((void* )mem_start_stk[mem]);
 
-        pend = (BIT_STATUS_AT(reg->bt_mem_end, mem)
+        pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
                 ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
                 : (UChar* )((void* )mem_end_stk[mem]));
         n = pend - pstart;
@@ -2254,12 +2270,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           if (mem_end_stk[mem]   == INVALID_STACK_INDEX) continue;
           if (mem_start_stk[mem] == INVALID_STACK_INDEX) continue;
 
-          if (BIT_STATUS_AT(reg->bt_mem_start, mem))
+          if (MEM_STATUS_AT(reg->bt_mem_start, mem))
             pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
           else
             pstart = (UChar* )((void* )mem_start_stk[mem]);
 
-          pend = (BIT_STATUS_AT(reg->bt_mem_end, mem)
+          pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
                   ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
                   : (UChar* )((void* )mem_end_stk[mem]));
           n = pend - pstart;
@@ -2293,12 +2309,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           if (mem_end_stk[mem]   == INVALID_STACK_INDEX) continue;
           if (mem_start_stk[mem] == INVALID_STACK_INDEX) continue;
 
-          if (BIT_STATUS_AT(reg->bt_mem_start, mem))
+          if (MEM_STATUS_AT(reg->bt_mem_start, mem))
             pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
           else
             pstart = (UChar* )((void* )mem_start_stk[mem]);
 
-          pend = (BIT_STATUS_AT(reg->bt_mem_end, mem)
+          pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
                   ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
                   : (UChar* )((void* )mem_end_stk[mem]));
           n = pend - pstart;
@@ -2364,25 +2380,24 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       break;
 #endif
 
-    case OP_NULL_CHECK_START:  MOP_IN(OP_NULL_CHECK_START);
+    case OP_EMPTY_CHECK_START:  MOP_IN(OP_EMPTY_CHECK_START);
       GET_MEMNUM_INC(mem, p);    /* mem: null check id */
-      STACK_PUSH_NULL_CHECK_START(mem, s);
+      STACK_PUSH_EMPTY_CHECK_START(mem, s);
       MOP_OUT;
       continue;
       break;
 
-    case OP_NULL_CHECK_END:  MOP_IN(OP_NULL_CHECK_END);
+    case OP_EMPTY_CHECK_END:  MOP_IN(OP_EMPTY_CHECK_END);
       {
-        int isnull;
+        int is_empty;
 
         GET_MEMNUM_INC(mem, p); /* mem: null check id */
-        STACK_NULL_CHECK(isnull, mem, s);
-        if (isnull) {
+        STACK_EMPTY_CHECK(is_empty, mem, s);
+        if (is_empty) {
 #ifdef ONIG_DEBUG_MATCH
-          fprintf(stderr, "NULL_CHECK_END: skip  id:%d, s:%d\n",
-                  (int )mem, (int )s);
+          fprintf(stderr, "EMPTY_CHECK_END: skip  id:%d, s:%p\n", (int )mem, s);
 #endif
-        null_check_found:
+        empty_check_found:
           /* empty loop founded, skip next instruction */
           switch (*p++) {
           case OP_JUMP:
@@ -2405,20 +2420,19 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       continue;
       break;
 
-#ifdef USE_MONOMANIAC_CHECK_CAPTURES_IN_ENDLESS_REPEAT
-    case OP_NULL_CHECK_END_MEMST:  MOP_IN(OP_NULL_CHECK_END_MEMST);
+#ifdef USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT
+    case OP_EMPTY_CHECK_END_MEMST:  MOP_IN(OP_EMPTY_CHECK_END_MEMST);
       {
-        int isnull;
+        int is_empty;
 
         GET_MEMNUM_INC(mem, p); /* mem: null check id */
-        STACK_NULL_CHECK_MEMST(isnull, mem, s, reg);
-        if (isnull) {
+        STACK_EMPTY_CHECK_MEMST(is_empty, mem, s, reg);
+        if (is_empty) {
 #ifdef ONIG_DEBUG_MATCH
-          fprintf(stderr, "NULL_CHECK_END_MEMST: skip  id:%d, s:%d\n",
-                  (int )mem, (int )s);
+          fprintf(stderr, "EMPTY_CHECK_END_MEMST: skip  id:%d, s:%p\n", (int)mem, s);
 #endif
-          if (isnull == -1) goto fail;
-          goto 	null_check_found;
+          if (is_empty == -1) goto fail;
+          goto 	empty_check_found;
         }
       }
       MOP_OUT;
@@ -2427,27 +2441,27 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 #endif
 
 #ifdef USE_SUBEXP_CALL
-    case OP_NULL_CHECK_END_MEMST_PUSH:
-      MOP_IN(OP_NULL_CHECK_END_MEMST_PUSH);
+    case OP_EMPTY_CHECK_END_MEMST_PUSH:
+      MOP_IN(OP_EMPTY_CHECK_END_MEMST_PUSH);
       {
-        int isnull;
+        int is_empty;
 
         GET_MEMNUM_INC(mem, p); /* mem: null check id */
-#ifdef USE_MONOMANIAC_CHECK_CAPTURES_IN_ENDLESS_REPEAT
-        STACK_NULL_CHECK_MEMST_REC(isnull, mem, s, reg);
+#ifdef USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT
+        STACK_EMPTY_CHECK_MEMST_REC(is_empty, mem, s, reg);
 #else
-        STACK_NULL_CHECK_REC(isnull, mem, s);
+        STACK_EMPTY_CHECK_REC(is_empty, mem, s);
 #endif
-        if (isnull) {
+        if (is_empty) {
 #ifdef ONIG_DEBUG_MATCH
-          fprintf(stderr, "NULL_CHECK_END_MEMST_PUSH: skip  id:%d, s:%d\n",
-                  (int )mem, (int )s);
+          fprintf(stderr, "EMPTY_CHECK_END_MEMST_PUSH: skip  id:%d, s:%p\n",
+                  (int )mem, s);
 #endif
-          if (isnull == -1) goto fail;
-          goto 	null_check_found;
+          if (is_empty == -1) goto fail;
+          goto 	empty_check_found;
         }
         else {
-          STACK_PUSH_NULL_CHECK_END(mem);
+          STACK_PUSH_EMPTY_CHECK_END(mem);
         }
       }
       MOP_OUT;
@@ -2923,8 +2937,8 @@ bm_search_notrev(regex_t* reg, const UChar* target, const UChar* target_end,
   int skip, tlen1;
 
 #ifdef ONIG_DEBUG_SEARCH
-  fprintf(stderr, "bm_search_notrev: text: %d, text_end: %d, text_range: %d\n",
-	  (int )text, (int )text_end, (int )text_range);
+  fprintf(stderr, "bm_search_notrev: text: %p, text_end: %p, text_range: %p\n",
+          text, text_end, text_range);
 #endif
 
   tail = target_end - 1;
@@ -3143,8 +3157,8 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
   UChar *p, *pprev = (UChar* )NULL;
 
 #ifdef ONIG_DEBUG_SEARCH
-  fprintf(stderr, "forward_search_range: str: %d, end: %d, s: %d, range: %d\n",
-	  (int )str, (int )end, (int )s, (int )range);
+  fprintf(stderr, "forward_search_range: str: %p, end: %p, s: %p, range: %p\n",
+          str, end, s, range);
 #endif
 
   p = s;
@@ -3309,7 +3323,7 @@ backward_search_range(regex_t* reg, const UChar* str, const UChar* end,
 
       r = set_bm_backward_skip(reg->exact, reg->exact_end, reg->enc,
                                &(reg->int_map_backward));
-      if (r) return r;
+      if (r != 0) return r;
     }
     p = bm_search_backward(reg, reg->exact, reg->exact_end, range, adjrange,
                            end, p);
@@ -3398,8 +3412,8 @@ onig_search(regex_t* reg, const UChar* str, const UChar* end,
 
 #ifdef ONIG_DEBUG_SEARCH
   fprintf(stderr,
-     "onig_search (entry point): str: %d, end: %d, start: %d, range: %d\n",
-     (int )str, (int )(end - str), (int )(start - str), (int )(range - str));
+     "onig_search (entry point): str: %p, end: %d, start: %d, range: %d\n",
+     str, (int )(end - str), (int )(start - str), (int )(range - str));
 #endif
 
   if (region
@@ -3408,7 +3422,7 @@ onig_search(regex_t* reg, const UChar* str, const UChar* end,
 #endif
       ) {
     r = onig_region_resize_clear(region, reg->num_mem + 1);
-    if (r) goto finish_no_msa;
+    if (r != 0) goto finish_no_msa;
   }
 
   if (start > end || start < str) goto mismatch_no_msa;
@@ -3853,7 +3867,7 @@ onig_number_of_capture_histories(regex_t* reg)
 
   n = 0;
   for (i = 0; i <= ONIG_MAX_CAPTURE_HISTORY_GROUP; i++) {
-    if (BIT_STATUS_AT(reg->capture_history, i) != 0)
+    if (MEM_STATUS_AT(reg->capture_history, i) != 0)
       n++;
   }
   return n;
diff --git a/src/regext.c b/src/regext.c
index 1903174..62a557c 100644
--- a/src/regext.c
+++ b/src/regext.c
@@ -2,7 +2,7 @@
   regext.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2008  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2017  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -171,7 +171,7 @@ onig_new_deluxe(regex_t** reg, const UChar* pattern, const UChar* pattern_end,
   if (ci->pattern_enc != ci->target_enc) {
     r = conv_encoding(ci->pattern_enc, ci->target_enc, pattern, pattern_end,
                       &cpat, &cpat_end);
-    if (r) return r;
+    if (r != 0) return r;
   }
   else {
     cpat     = (UChar* )pattern;
@@ -186,10 +186,10 @@ onig_new_deluxe(regex_t** reg, const UChar* pattern, const UChar* pattern_end,
 
   r = onig_reg_init(*reg, ci->option, ci->case_fold_flag, ci->target_enc,
 		    ci->syntax);
-  if (r) goto err;
+  if (r != 0) goto err;
 
   r = onig_compile(*reg, cpat, cpat_end, einfo);
-  if (r) {
+  if (r != 0) {
   err:
     onig_free(*reg);
     *reg = NULL;
diff --git a/src/regint.h b/src/regint.h
index 9835143..8da27d2 100644
--- a/src/regint.h
+++ b/src/regint.h
@@ -4,7 +4,7 @@
   regint.h -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2013  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2017  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -59,14 +59,14 @@
 #define USE_NAMED_GROUP
 #define USE_SUBEXP_CALL
 #define USE_BACKREF_WITH_LEVEL        /* \k<name+n>, \k<name-n> */
-#define USE_MONOMANIAC_CHECK_CAPTURES_IN_ENDLESS_REPEAT  /* /(?:()|())*\2/ */
+#define USE_INSISTENT_CHECK_CAPTURES_STATUS_IN_ENDLESS_REPEAT  /* /(?:()|())*\2/ */
 #define USE_NEWLINE_AT_END_OF_STRING_HAS_EMPTY_LINE     /* /\n$/ =~ "\n" */
 #define USE_WARNING_REDUNDANT_NESTED_REPEAT_OPERATOR
 /* !!! moved to regenc.h. */ /* #define USE_CRNL_AS_LINE_TERMINATOR */
 
 /* internal config */
 #define USE_OP_PUSH_OR_JUMP_EXACT
-#define USE_QTFR_PEEK_NEXT
+#define USE_QUANT_PEEK_NEXT
 #define USE_ST_LIBRARY
 
 #define INIT_MATCH_STACK_SIZE                     160
@@ -161,6 +161,10 @@
 #endif
 #endif
 
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+
 #ifdef __BORLANDC__
 #include <malloc.h>
 #endif
@@ -169,6 +173,12 @@
 # include <stdio.h>
 #endif
 
+#ifdef _WIN32
+#if defined(_MSC_VER) && (_MSC_VER < 1300)
+typedef int intptr_t;
+#endif
+#endif
+
 #include "regenc.h"
 
 #ifdef MIN
@@ -230,24 +240,28 @@
 #define ONIG_OPTIMIZE_MAP               5   /* char map */
 
 /* bit status */
-typedef unsigned int  BitStatusType;
-
-#define BIT_STATUS_BITS_NUM          (sizeof(BitStatusType) * 8)
-#define BIT_STATUS_CLEAR(stats)      (stats) = 0
-#define BIT_STATUS_ON_ALL(stats)     (stats) = ~((BitStatusType )0)
-#define BIT_STATUS_AT(stats,n) \
-  ((n) < (int )BIT_STATUS_BITS_NUM  ?  ((stats) & (1 << n)) : ((stats) & 1))
-
-#define BIT_STATUS_ON_AT(stats,n) do {\
-    if ((n) < (int )BIT_STATUS_BITS_NUM)	\
-    (stats) |= (1 << (n));\
+typedef unsigned int  MemStatusType;
+
+#define MEM_STATUS_BITS_NUM          (sizeof(MemStatusType) * 8)
+#define MEM_STATUS_CLEAR(stats)      (stats) = 0
+#define MEM_STATUS_ON_ALL(stats)     (stats) = ~((MemStatusType )0)
+#define MEM_STATUS_AT(stats,n) \
+  ((n) < (int )MEM_STATUS_BITS_NUM  ?  ((stats) & ((MemStatusType )1 << n)) : ((stats) & 1))
+#define MEM_STATUS_AT0(stats,n) \
+  ((n) > 0 && (n) < (int )MEM_STATUS_BITS_NUM  ?  ((stats) & ((MemStatusType )1 << n)) : ((stats) & 1))
+
+#define MEM_STATUS_ON(stats,n) do {\
+  if ((n) < (int )MEM_STATUS_BITS_NUM) {\
+    if ((n) != 0)\
+      (stats) |= ((MemStatusType )1 << (n));\
+  }\
   else\
     (stats) |= 1;\
 } while (0)
 
-#define BIT_STATUS_ON_AT_SIMPLE(stats,n) do {\
-    if ((n) < (int )BIT_STATUS_BITS_NUM)\
-    (stats) |= (1 << (n));\
+#define MEM_STATUS_ON_SIMPLE(stats,n) do {\
+    if ((n) < (int )MEM_STATUS_BITS_NUM)\
+    (stats) |= ((MemStatusType )1 << (n));\
 } while (0)
 
 
@@ -394,25 +408,28 @@ typedef struct _BBuf {
 #define BBUF_GET_BYTE(buf, pos) (buf)->p[(pos)]
 
 
-#define ANCHOR_BEGIN_BUF        (1<<0)
-#define ANCHOR_BEGIN_LINE       (1<<1)
-#define ANCHOR_BEGIN_POSITION   (1<<2)
-#define ANCHOR_END_BUF          (1<<3)
-#define ANCHOR_SEMI_END_BUF     (1<<4)
-#define ANCHOR_END_LINE         (1<<5)
-
-#define ANCHOR_WORD_BOUND       (1<<6)
-#define ANCHOR_NOT_WORD_BOUND   (1<<7)
-#define ANCHOR_WORD_BEGIN       (1<<8)
-#define ANCHOR_WORD_END         (1<<9)
-#define ANCHOR_PREC_READ        (1<<10)
-#define ANCHOR_PREC_READ_NOT    (1<<11)
-#define ANCHOR_LOOK_BEHIND      (1<<12)
-#define ANCHOR_LOOK_BEHIND_NOT  (1<<13)
-
+/* has body */
+#define ANCHOR_PREC_READ        (1<<0)
+#define ANCHOR_PREC_READ_NOT    (1<<1)
+#define ANCHOR_LOOK_BEHIND      (1<<2)
+#define ANCHOR_LOOK_BEHIND_NOT  (1<<3)
+/* no body */
+#define ANCHOR_BEGIN_BUF        (1<<4)
+#define ANCHOR_BEGIN_LINE       (1<<5)
+#define ANCHOR_BEGIN_POSITION   (1<<6)
+#define ANCHOR_END_BUF          (1<<7)
+#define ANCHOR_SEMI_END_BUF     (1<<8)
+#define ANCHOR_END_LINE         (1<<9)
+#define ANCHOR_WORD_BOUND       (1<<10)
+#define ANCHOR_NOT_WORD_BOUND   (1<<11)
+#define ANCHOR_WORD_BEGIN       (1<<12)
+#define ANCHOR_WORD_END         (1<<13)
 #define ANCHOR_ANYCHAR_STAR     (1<<14)   /* ".*" optimize info */
 #define ANCHOR_ANYCHAR_STAR_ML  (1<<15)   /* ".*" optimize info (multi-line) */
 
+#define ANCHOR_HAS_BODY(a)      ((a)->type < ANCHOR_BEGIN_BUF)
+
+
 /* operation code */
 enum OpCode {
   OP_FINISH = 0,        /* matching process terminator (no more alternative) */
@@ -490,10 +507,10 @@ enum OpCode {
   OP_REPEAT_INC_NG,        /* non greedy */
   OP_REPEAT_INC_SG,        /* search and get in stack */
   OP_REPEAT_INC_NG_SG,     /* search and get in stack (non greedy) */
-  OP_NULL_CHECK_START,     /* null loop checker start */
-  OP_NULL_CHECK_END,       /* null loop checker end   */
-  OP_NULL_CHECK_END_MEMST, /* null loop checker end (with capture status) */
-  OP_NULL_CHECK_END_MEMST_PUSH, /* with capture status and push check-end */
+  OP_EMPTY_CHECK_START,     /* null loop checker start */
+  OP_EMPTY_CHECK_END,       /* null loop checker end   */
+  OP_EMPTY_CHECK_END_MEMST, /* null loop checker end (with capture status) */
+  OP_EMPTY_CHECK_END_MEMST_PUSH, /* with capture status and push check-end */
 
   OP_PUSH_POS,             /* (?=...)  start */
   OP_POP_POS,              /* (?=...)  end   */
@@ -581,8 +598,8 @@ typedef void* PointerType;
 #define SIZE_OP_MEMORY_END_REC         (SIZE_OPCODE + SIZE_MEMNUM)
 #define SIZE_OP_PUSH_STOP_BT            SIZE_OPCODE
 #define SIZE_OP_POP_STOP_BT             SIZE_OPCODE
-#define SIZE_OP_NULL_CHECK_START       (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_NULL_CHECK_END         (SIZE_OPCODE + SIZE_MEMNUM)
+#define SIZE_OP_EMPTY_CHECK_START       (SIZE_OPCODE + SIZE_MEMNUM)
+#define SIZE_OP_EMPTY_CHECK_END         (SIZE_OPCODE + SIZE_MEMNUM)
 #define SIZE_OP_LOOK_BEHIND            (SIZE_OPCODE + SIZE_LENGTH)
 #define SIZE_OP_PUSH_LOOK_BEHIND_NOT   (SIZE_OPCODE + SIZE_RELADDR + SIZE_LENGTH)
 #define SIZE_OP_FAIL_LOOK_BEHIND_NOT    SIZE_OPCODE
@@ -644,25 +661,10 @@ typedef void* PointerType;
 #define FLAG_NCCLASS_SHARE         (1<<1)
 
 #define NCCLASS_SET_NOT(nd)     NCCLASS_FLAG_SET(nd, FLAG_NCCLASS_NOT)
-#define NCCLASS_SET_SHARE(nd)   NCCLASS_FLAG_SET(nd, FLAG_NCCLASS_SHARE)
 #define NCCLASS_CLEAR_NOT(nd)   NCCLASS_FLAG_CLEAR(nd, FLAG_NCCLASS_NOT)
 #define IS_NCCLASS_NOT(nd)      IS_NCCLASS_FLAG_ON(nd, FLAG_NCCLASS_NOT)
-#define IS_NCCLASS_SHARE(nd)    IS_NCCLASS_FLAG_ON(nd, FLAG_NCCLASS_SHARE)
-
-typedef struct {
-  int type;
-  /* struct _Node* next; */
-  /* unsigned int flags; */
-} NodeBase;
-
-typedef struct {
-  NodeBase base;
-  unsigned int flags;
-  BitSet bs;
-  BBuf*  mbuf;   /* multi-byte info or NULL */
-} CClassNode;
 
-typedef long OnigStackIndex;
+typedef intptr_t OnigStackIndex;
 
 typedef struct _OnigStackType {
   unsigned int type;
@@ -693,7 +695,7 @@ typedef struct _OnigStackType {
     struct {
       int num;           /* null check id */
       UChar *pstr;       /* start position */
-    } null_check;
+    } empty_check;
 #ifdef USE_SUBEXP_CALL
     struct {
       UChar *ret_addr;   /* byte code position */
@@ -744,7 +746,7 @@ typedef struct {
 extern OnigOpInfoType OnigOpInfo[];
 
 
-extern void onig_print_compiled_byte_code P_((FILE* f, UChar* bp, UChar** nextp, OnigEncoding enc));
+extern void onig_print_compiled_byte_code P_((FILE* f, UChar* bp, UChar** nextp, UChar* start, OnigEncoding enc));
 
 #ifdef ONIG_DEBUG_STATISTICS
 extern void onig_statistics_init P_((void));
@@ -758,8 +760,7 @@ extern void  onig_snprintf_with_pattern PV_((UChar buf[], int bufsize, OnigEncod
 extern int  onig_bbuf_init P_((BBuf* buf, int size));
 extern int  onig_compile P_((regex_t* reg, const UChar* pattern, const UChar* pattern_end, OnigErrorInfo* einfo));
 extern void onig_transfer P_((regex_t* to, regex_t* from));
-extern int  onig_is_code_in_cc P_((OnigEncoding enc, OnigCodePoint code, CClassNode* cc));
-extern int  onig_is_code_in_cc_len P_((int enclen, OnigCodePoint code, CClassNode* cc));
+extern int  onig_is_code_in_cc_len P_((int enclen, OnigCodePoint code, void* /* CClassNode* */ cc));
 
 /* strend hash */
 typedef void hash_table_type;
diff --git a/src/regparse.c b/src/regparse.c
index 8153513..a5f8e5b 100644
--- a/src/regparse.c
+++ b/src/regparse.c
@@ -159,14 +159,25 @@ bbuf_clone(BBuf** rto, BBuf* from)
   *rto = to = (BBuf* )xmalloc(sizeof(BBuf));
   CHECK_NULL_RETURN_MEMERR(to);
   r = BBUF_INIT(to, from->alloc);
-  if (r != 0) return r;
+  if (r != 0) {
+    xfree(to->p);
+    *rto = 0;
+    return r;
+  }
   to->used = from->used;
   xmemcpy(to->p, from->p, from->used);
   return 0;
 }
 
-#define BACKREF_REL_TO_ABS(rel_no, env) \
-  ((env)->num_mem + 1 + (rel_no))
+static int backref_rel_to_abs(int rel_no, ScanEnv* env)
+{
+  if (rel_no > 0) {
+    return env->num_mem + rel_no;
+  }
+  else {
+    return env->num_mem + 1 + rel_no;
+  }
+}
 
 #define ONOFF(v,f,negative)    (negative) ? ((v) &= ~(f)) : ((v) |= (f))
 
@@ -179,7 +190,7 @@ bbuf_clone(BBuf** rto, BBuf* from)
 #define ADD_ALL_MULTI_BYTE_RANGE(enc, mbuf) do {\
   if (! ONIGENC_IS_SINGLEBYTE(enc)) {\
     r = SET_ALL_MULTI_BYTE_RANGE(enc, &(mbuf));\
-    if (r) return r;\
+    if (r != 0) return r;\
   }\
 } while (0)
 
@@ -422,6 +433,8 @@ onig_st_insert_strend(hash_table_type* table, const UChar* str_key,
   int result;
 
   key = (st_str_end_key* )xmalloc(sizeof(st_str_end_key));
+  CHECK_NULL_RETURN_MEMERR(key);
+
   key->s   = (UChar* )str_key;
   key->end = (UChar* )end_key;
   result = onig_st_insert(table, (st_data_t )key, value);
@@ -519,7 +532,7 @@ onig_names_free(regex_t* reg)
   NameTable* t;
 
   r = names_clear(reg);
-  if (r) return r;
+  if (r != 0) return r;
 
   t = (NameTable* )reg->name_table;
   if (IS_NOT_NULL(t)) onig_st_free_table(t);
@@ -700,7 +713,7 @@ onig_names_free(regex_t* reg)
   NameTable* t;
 
   r = names_clear(reg);
-  if (r) return r;
+  if (r != 0) return r;
 
   t = (NameTable* )reg->name_table;
   if (IS_NOT_NULL(t)) xfree(t);
@@ -762,6 +775,7 @@ onig_number_of_names(regex_t* reg)
 static int
 name_add(regex_t* reg, UChar* name, UChar* name_end, int backref, ScanEnv* env)
 {
+  int r;
   int alloc;
   NameEntry* e;
   NameTable* t = (NameTable* )reg->name_table;
@@ -783,8 +797,9 @@ name_add(regex_t* reg, UChar* name, UChar* name_end, int backref, ScanEnv* env)
     if (IS_NULL(e->name)) {
       xfree(e);  return ONIGERR_MEMORY;
     }
-    onig_st_insert_strend(t, e->name, (e->name + (name_end - name)),
-                          (HashDataType )e);
+    r = onig_st_insert_strend(t, e->name, (e->name + (name_end - name)),
+                              (HashDataType )e);
+    if (r < 0) return r;
 
     e->name_len   = name_end - name;
     e->back_num   = 0;
@@ -918,14 +933,14 @@ onig_name_to_backref_number(regex_t* reg, const UChar* name,
 
 extern int
 onig_name_to_group_numbers(regex_t* reg, const UChar* name,
-			   const UChar* name_end, int** nums)
+                           const UChar* name_end, int** nums)
 {
   return ONIG_NO_SUPPORT_CONFIG;
 }
 
 extern int
 onig_name_to_backref_number(regex_t* reg, const UChar* name,
-			    const UChar* name_end, OnigRegion* region)
+                            const UChar* name_end, OnigRegion* region)
 {
   return ONIG_NO_SUPPORT_CONFIG;
 }
@@ -962,29 +977,32 @@ onig_noname_group_capture_is_active(regex_t* reg)
 }
 
 
-#define INIT_SCANENV_MEMNODES_ALLOC_SIZE   16
+#define INIT_SCANENV_MEMENV_ALLOC_SIZE   16
 
 static void
 scan_env_clear(ScanEnv* env)
 {
-  int i;
-
-  BIT_STATUS_CLEAR(env->capture_history);
-  BIT_STATUS_CLEAR(env->bt_mem_start);
-  BIT_STATUS_CLEAR(env->bt_mem_end);
-  BIT_STATUS_CLEAR(env->backrefed_mem);
+  MEM_STATUS_CLEAR(env->capture_history);
+  MEM_STATUS_CLEAR(env->bt_mem_start);
+  MEM_STATUS_CLEAR(env->bt_mem_end);
+  MEM_STATUS_CLEAR(env->backrefed_mem);
   env->error      = (UChar* )NULL;
   env->error_end  = (UChar* )NULL;
   env->num_call   = 0;
+
+#ifdef USE_SUBEXP_CALL
+  env->unset_addr_list = NULL;
+  env->has_call_zero   = 0;
+#endif
+
   env->num_mem    = 0;
 #ifdef USE_NAMED_GROUP
   env->num_named  = 0;
 #endif
-  env->mem_alloc         = 0;
-  env->mem_nodes_dynamic = (Node** )NULL;
+  env->mem_alloc       = 0;
+  env->mem_env_dynamic = (MemEnv* )NULL;
 
-  for (i = 0; i < SCANENV_MEMNODES_SIZE; i++)
-    env->mem_nodes_static[i] = NULL_NODE;
+  xmemset(env->mem_env_static, 0, sizeof(env->mem_env_static));
 
 #ifdef USE_COMBINATION_EXPLOSION_CHECK
   env->num_comb_exp_check  = 0;
@@ -999,30 +1017,35 @@ static int
 scan_env_add_mem_entry(ScanEnv* env)
 {
   int i, need, alloc;
-  Node** p;
+  MemEnv* p;
 
   need = env->num_mem + 1;
   if (need > MaxCaptureNum && MaxCaptureNum != 0)
     return ONIGERR_TOO_MANY_CAPTURES;
 
-  if (need >= SCANENV_MEMNODES_SIZE) {
+  if (need >= SCANENV_MEMENV_SIZE) {
     if (env->mem_alloc <= need) {
-      if (IS_NULL(env->mem_nodes_dynamic)) {
-        alloc = INIT_SCANENV_MEMNODES_ALLOC_SIZE;
-        p = (Node** )xmalloc(sizeof(Node*) * alloc);
-        xmemcpy(p, env->mem_nodes_static,
-                sizeof(Node*) * SCANENV_MEMNODES_SIZE);
+      if (IS_NULL(env->mem_env_dynamic)) {
+        alloc = INIT_SCANENV_MEMENV_ALLOC_SIZE;
+        p = (MemEnv* )xmalloc(sizeof(MemEnv) * alloc);
+        CHECK_NULL_RETURN_MEMERR(p);
+        xmemcpy(p, env->mem_env_static, sizeof(env->mem_env_static));
       }
       else {
         alloc = env->mem_alloc * 2;
-        p = (Node** )xrealloc(env->mem_nodes_dynamic, sizeof(Node*) * alloc);
+        p = (MemEnv* )xrealloc(env->mem_env_dynamic, sizeof(MemEnv) * alloc);
+        CHECK_NULL_RETURN_MEMERR(p);
       }
-      CHECK_NULL_RETURN_MEMERR(p);
 
-      for (i = env->num_mem + 1; i < alloc; i++)
-        p[i] = NULL_NODE;
+      for (i = env->num_mem + 1; i < alloc; i++) {
+        p[i].node = NULL_NODE;
+#if 0
+        p[i].in   = 0;
+        p[i].recursion = 0;
+#endif
+      }
 
-      env->mem_nodes_dynamic = p;
+      env->mem_env_dynamic = p;
       env->mem_alloc = alloc;
     }
   }
@@ -1035,7 +1058,7 @@ static int
 scan_env_set_mem_node(ScanEnv* env, int num, Node* node)
 {
   if (env->num_mem >= num)
-    SCANENV_MEM_NODES(env)[num] = node;
+    SCANENV_MEMENV(env)[num].node = node;
   else
     return ONIGERR_PARSER_BUG;
   return 0;
@@ -1051,19 +1074,19 @@ onig_node_free(Node* node)
   fprintf(stderr, "onig_node_free: %p\n", node);
 #endif
 
-  switch (NTYPE(node)) {
-  case NT_STR:
-    if (NSTR(node)->capa != 0 &&
-        IS_NOT_NULL(NSTR(node)->s) && NSTR(node)->s != NSTR(node)->buf) {
-      xfree(NSTR(node)->s);
+  switch (NODE_TYPE(node)) {
+  case NODE_STR:
+    if (STR_(node)->capa != 0 &&
+        IS_NOT_NULL(STR_(node)->s) && STR_(node)->s != STR_(node)->buf) {
+      xfree(STR_(node)->s);
     }
     break;
 
-  case NT_LIST:
-  case NT_ALT:
-    onig_node_free(NCAR(node));
+  case NODE_LIST:
+  case NODE_ALT:
+    onig_node_free(NODE_CAR(node));
     {
-      Node* next_node = NCDR(node);
+      Node* next_node = NODE_CDR(node);
 
       xfree(node);
       node = next_node;
@@ -1071,34 +1094,29 @@ onig_node_free(Node* node)
     }
     break;
 
-  case NT_CCLASS:
+  case NODE_CCLASS:
     {
-      CClassNode* cc = NCCLASS(node);
+      CClassNode* cc = CCLASS_(node);
 
-      if (IS_NCCLASS_SHARE(cc)) return ;
       if (cc->mbuf)
         bbuf_free(cc->mbuf);
     }
     break;
 
-  case NT_QTFR:
-    if (NQTFR(node)->target)
-      onig_node_free(NQTFR(node)->target);
-    break;
-
-  case NT_ENCLOSE:
-    if (NENCLOSE(node)->target)
-      onig_node_free(NENCLOSE(node)->target);
+  case NODE_BREF:
+    if (IS_NOT_NULL(BREF_(node)->back_dynamic))
+      xfree(BREF_(node)->back_dynamic);
     break;
 
-  case NT_BREF:
-    if (IS_NOT_NULL(NBREF(node)->back_dynamic))
-      xfree(NBREF(node)->back_dynamic);
+  case NODE_QUANT:
+  case NODE_ENCLOSURE:
+  case NODE_ANCHOR:
+    if (NODE_BODY(node))
+      onig_node_free(NODE_BODY(node));
     break;
 
-  case NT_ANCHOR:
-    if (NANCHOR(node)->target)
-      onig_node_free(NANCHOR(node)->target);
+  case NODE_CTYPE:
+  case NODE_CALL:
     break;
   }
 
@@ -1111,7 +1129,9 @@ node_new(void)
   Node* node;
 
   node = (Node* )xmalloc(sizeof(Node));
-  /* xmemset(node, 0, sizeof(Node)); */
+  //xmemset(node, 0, sizeof(node->u.base));
+  xmemset(node, 0, sizeof(*node));
+
 #ifdef DEBUG_NODE_FREE
   fprintf(stderr, "node_new: %p\n", node);
 #endif
@@ -1134,8 +1154,8 @@ node_new_cclass(void)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_CCLASS);
-  initialize_cclass(NCCLASS(node));
+  SET_NODE_TYPE(node, NODE_CCLASS);
+  initialize_cclass(CCLASS_(node));
   return node;
 }
 
@@ -1145,19 +1165,9 @@ node_new_ctype(int type, int not)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_CTYPE);
-  NCTYPE(node)->ctype = type;
-  NCTYPE(node)->not   = not;
-  return node;
-}
-
-static Node*
-node_new_anychar(void)
-{
-  Node* node = node_new();
-  CHECK_NULL_RETURN(node);
-
-  SET_NTYPE(node, NT_CANY);
+  SET_NODE_TYPE(node, NODE_CTYPE);
+  CTYPE_(node)->ctype = type;
+  CTYPE_(node)->not   = not;
   return node;
 }
 
@@ -1167,9 +1177,9 @@ node_new_list(Node* left, Node* right)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_LIST);
-  NCAR(node)  = left;
-  NCDR(node) = right;
+  SET_NODE_TYPE(node, NODE_LIST);
+  NODE_CAR(node)  = left;
+  NODE_CDR(node) = right;
   return node;
 }
 
@@ -1188,10 +1198,10 @@ onig_node_list_add(Node* list, Node* x)
   if (IS_NULL(n)) return NULL_NODE;
 
   if (IS_NOT_NULL(list)) {
-    while (IS_NOT_NULL(NCDR(list)))
-      list = NCDR(list);
+    while (IS_NOT_NULL(NODE_CDR(list)))
+      list = NODE_CDR(list);
 
-    NCDR(list) = n;
+    NODE_CDR(list) = n;
   }
 
   return n;
@@ -1203,9 +1213,9 @@ onig_node_new_alt(Node* left, Node* right)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_ALT);
-  NCAR(node)  = left;
-  NCDR(node) = right;
+  SET_NODE_TYPE(node, NODE_ALT);
+  NODE_CAR(node)  = left;
+  NODE_CDR(node) = right;
   return node;
 }
 
@@ -1215,10 +1225,9 @@ onig_node_new_anchor(int type)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_ANCHOR);
-  NANCHOR(node)->type     = type;
-  NANCHOR(node)->target   = NULL;
-  NANCHOR(node)->char_len = -1;
+  SET_NODE_TYPE(node, NODE_ANCHOR);
+  ANCHOR_(node)->type     = type;
+  ANCHOR_(node)->char_len = -1;
   return node;
 }
 
@@ -1234,31 +1243,30 @@ node_new_backref(int back_num, int* backrefs, int by_name,
 
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_BREF);
-  NBREF(node)->state    = 0;
-  NBREF(node)->back_num = back_num;
-  NBREF(node)->back_dynamic = (int* )NULL;
+  SET_NODE_TYPE(node, NODE_BREF);
+  BREF_(node)->back_num = back_num;
+  BREF_(node)->back_dynamic = (int* )NULL;
   if (by_name != 0)
-    NBREF(node)->state |= NST_NAME_REF;
+    NODE_STATUS_ADD(node, NST_BY_NAME);
 
 #ifdef USE_BACKREF_WITH_LEVEL
   if (exist_level != 0) {
-    NBREF(node)->state |= NST_NEST_LEVEL;
-    NBREF(node)->nest_level  = nest_level;
+    NODE_STATUS_ADD(node, NST_NEST_LEVEL);
+    BREF_(node)->nest_level  = nest_level;
   }
 #endif
 
   for (i = 0; i < back_num; i++) {
     if (backrefs[i] <= env->num_mem &&
-        IS_NULL(SCANENV_MEM_NODES(env)[backrefs[i]])) {
-      NBREF(node)->state |= NST_RECURSION;   /* /...(\1).../ */
+        IS_NULL(SCANENV_MEMENV(env)[backrefs[i]].node)) {
+      NODE_STATUS_ADD(node, NST_RECURSION);   /* /...(\1).../ */
       break;
     }
   }
 
   if (back_num <= NODE_BACKREFS_SIZE) {
     for (i = 0; i < back_num; i++)
-      NBREF(node)->back_static[i] = backrefs[i];
+      BREF_(node)->back_static[i] = backrefs[i];
   }
   else {
     int* p = (int* )xmalloc(sizeof(int) * back_num);
@@ -1266,7 +1274,7 @@ node_new_backref(int back_num, int* backrefs, int by_name,
       onig_node_free(node);
       return NULL;
     }
-    NBREF(node)->back_dynamic = p;
+    BREF_(node)->back_dynamic = p;
     for (i = 0; i < back_num; i++)
       p[i] = backrefs[i];
   }
@@ -1275,17 +1283,17 @@ node_new_backref(int back_num, int* backrefs, int by_name,
 
 #ifdef USE_SUBEXP_CALL
 static Node*
-node_new_call(UChar* name, UChar* name_end, int gnum)
+node_new_call(UChar* name, UChar* name_end, int gnum, int by_number)
 {
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_CALL);
-  NCALL(node)->state     = 0;
-  NCALL(node)->target    = NULL_NODE;
-  NCALL(node)->name      = name;
-  NCALL(node)->name_end  = name_end;
-  NCALL(node)->group_num = gnum;  /* call by number if gnum != 0 */
+  SET_NODE_TYPE(node, NODE_CALL);
+  CALL_(node)->by_number   = by_number;
+  CALL_(node)->name        = name;
+  CALL_(node)->name_end    = name_end;
+  CALL_(node)->group_num   = gnum;
+  CALL_(node)->entry_count = 1;
   return node;
 }
 #endif
@@ -1296,69 +1304,76 @@ node_new_quantifier(int lower, int upper, int by_number)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_QTFR);
-  NQTFR(node)->state  = 0;
-  NQTFR(node)->target = NULL;
-  NQTFR(node)->lower  = lower;
-  NQTFR(node)->upper  = upper;
-  NQTFR(node)->greedy = 1;
-  NQTFR(node)->target_empty_info = NQ_TARGET_ISNOT_EMPTY;
-  NQTFR(node)->head_exact        = NULL_NODE;
-  NQTFR(node)->next_head_exact   = NULL_NODE;
-  NQTFR(node)->is_refered        = 0;
+  SET_NODE_TYPE(node, NODE_QUANT);
+  QUANT_(node)->lower  = lower;
+  QUANT_(node)->upper  = upper;
+  QUANT_(node)->greedy = 1;
+  QUANT_(node)->body_empty_info = QUANT_BODY_IS_NOT_EMPTY;
+  QUANT_(node)->head_exact      = NULL_NODE;
+  QUANT_(node)->next_head_exact = NULL_NODE;
+  QUANT_(node)->is_refered      = 0;
   if (by_number != 0)
-    NQTFR(node)->state |= NST_BY_NUMBER;
+    NODE_STATUS_ADD(node, NST_BY_NUMBER);
 
 #ifdef USE_COMBINATION_EXPLOSION_CHECK
-  NQTFR(node)->comb_exp_check_num = 0;
+  QUANT_(node)->comb_exp_check_num = 0;
 #endif
 
   return node;
 }
 
 static Node*
-node_new_enclose(int type)
+node_new_enclosure(int type)
 {
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_ENCLOSE);
-  NENCLOSE(node)->type      = type;
-  NENCLOSE(node)->state     =  0;
-  NENCLOSE(node)->regnum    =  0;
-  NENCLOSE(node)->option    =  0;
-  NENCLOSE(node)->target    = NULL;
-  NENCLOSE(node)->call_addr = -1;
-  NENCLOSE(node)->opt_count =  0;
+  SET_NODE_TYPE(node, NODE_ENCLOSURE);
+  ENCLOSURE_(node)->type = type;
+
+  switch (type) {
+  case ENCLOSURE_MEMORY:
+    ENCLOSURE_(node)->m.regnum       =  0;
+    ENCLOSURE_(node)->m.called_addr  = -1;
+    ENCLOSURE_(node)->m.entry_count  =  1;
+    ENCLOSURE_(node)->m.called_state =  0;
+    break;
+
+  case ENCLOSURE_OPTION:
+    ENCLOSURE_(node)->o.option =  0;
+    break;
+
+  case ENCLOSURE_STOP_BACKTRACK:
+    break;
+  }
+
+  ENCLOSURE_(node)->opt_count = 0;
   return node;
 }
 
 extern Node*
-onig_node_new_enclose(int type)
+onig_node_new_enclosure(int type)
 {
-  return node_new_enclose(type);
+  return node_new_enclosure(type);
 }
 
 static Node*
-node_new_enclose_memory(OnigOptionType option, int is_named)
+node_new_enclosure_memory(int is_named)
 {
-  Node* node = node_new_enclose(ENCLOSE_MEMORY);
+  Node* node = node_new_enclosure(ENCLOSURE_MEMORY);
   CHECK_NULL_RETURN(node);
   if (is_named != 0)
-    SET_ENCLOSE_STATUS(node, NST_NAMED_GROUP);
+    NODE_STATUS_ADD(node, NST_NAMED_GROUP);
 
-#ifdef USE_SUBEXP_CALL
-  NENCLOSE(node)->option = option;
-#endif
   return node;
 }
 
 static Node*
 node_new_option(OnigOptionType option)
 {
-  Node* node = node_new_enclose(ENCLOSE_OPTION);
+  Node* node = node_new_enclosure(ENCLOSURE_OPTION);
   CHECK_NULL_RETURN(node);
-  NENCLOSE(node)->option = option;
+  ENCLOSURE_(node)->o.option = option;
   return node;
 }
 
@@ -1368,31 +1383,31 @@ onig_node_str_cat(Node* node, const UChar* s, const UChar* end)
   int addlen = end - s;
 
   if (addlen > 0) {
-    int len  = NSTR(node)->end - NSTR(node)->s;
+    int len  = STR_(node)->end - STR_(node)->s;
 
-    if (NSTR(node)->capa > 0 || (len + addlen > NODE_STR_BUF_SIZE - 1)) {
+    if (STR_(node)->capa > 0 || (len + addlen > NODE_STR_BUF_SIZE - 1)) {
       UChar* p;
       int capa = len + addlen + NODE_STR_MARGIN;
 
-      if (capa <= NSTR(node)->capa) {
-        onig_strcpy(NSTR(node)->s + len, s, end);
+      if (capa <= STR_(node)->capa) {
+        onig_strcpy(STR_(node)->s + len, s, end);
       }
       else {
-        if (NSTR(node)->s == NSTR(node)->buf)
-          p = strcat_capa_from_static(NSTR(node)->s, NSTR(node)->end,
+        if (STR_(node)->s == STR_(node)->buf)
+          p = strcat_capa_from_static(STR_(node)->s, STR_(node)->end,
                                       s, end, capa);
         else
-          p = strcat_capa(NSTR(node)->s, NSTR(node)->end, s, end, capa);
+          p = strcat_capa(STR_(node)->s, STR_(node)->end, s, end, capa);
 
         CHECK_NULL_RETURN_MEMERR(p);
-        NSTR(node)->s    = p;
-        NSTR(node)->capa = capa;
+        STR_(node)->s    = p;
+        STR_(node)->capa = capa;
       }
     }
     else {
-      onig_strcpy(NSTR(node)->s + len, s, end);
+      onig_strcpy(STR_(node)->s + len, s, end);
     }
-    NSTR(node)->end = NSTR(node)->s + len + addlen;
+    STR_(node)->end = STR_(node)->s + len + addlen;
   }
 
   return 0;
@@ -1417,25 +1432,25 @@ node_str_cat_char(Node* node, UChar c)
 extern void
 onig_node_conv_to_str_node(Node* node, int flag)
 {
-  SET_NTYPE(node, NT_STR);
-  NSTR(node)->flag = flag;
-  NSTR(node)->capa = 0;
-  NSTR(node)->s    = NSTR(node)->buf;
-  NSTR(node)->end  = NSTR(node)->buf;
+  SET_NODE_TYPE(node, NODE_STR);
+  STR_(node)->flag = flag;
+  STR_(node)->capa = 0;
+  STR_(node)->s    = STR_(node)->buf;
+  STR_(node)->end  = STR_(node)->buf;
 }
 
 extern void
 onig_node_str_clear(Node* node)
 {
-  if (NSTR(node)->capa != 0 &&
-      IS_NOT_NULL(NSTR(node)->s) && NSTR(node)->s != NSTR(node)->buf) {
-    xfree(NSTR(node)->s);
+  if (STR_(node)->capa != 0 &&
+      IS_NOT_NULL(STR_(node)->s) && STR_(node)->s != STR_(node)->buf) {
+    xfree(STR_(node)->s);
   }
 
-  NSTR(node)->capa = 0;
-  NSTR(node)->flag = 0;
-  NSTR(node)->s    = NSTR(node)->buf;
-  NSTR(node)->end  = NSTR(node)->buf;
+  STR_(node)->capa = 0;
+  STR_(node)->flag = 0;
+  STR_(node)->s    = STR_(node)->buf;
+  STR_(node)->end  = STR_(node)->buf;
 }
 
 static Node*
@@ -1444,11 +1459,11 @@ node_new_str(const UChar* s, const UChar* end)
   Node* node = node_new();
   CHECK_NULL_RETURN(node);
 
-  SET_NTYPE(node, NT_STR);
-  NSTR(node)->capa = 0;
-  NSTR(node)->flag = 0;
-  NSTR(node)->s    = NSTR(node)->buf;
-  NSTR(node)->end  = NSTR(node)->buf;
+  SET_NODE_TYPE(node, NODE_STR);
+  STR_(node)->capa = 0;
+  STR_(node)->flag = 0;
+  STR_(node)->s    = STR_(node)->buf;
+  STR_(node)->end  = STR_(node)->buf;
   if (onig_node_str_cat(node, s, end)) {
     onig_node_free(node);
     return NULL;
@@ -1495,7 +1510,7 @@ str_node_split_last_char(StrNode* sn, OnigEncoding enc)
     p = onigenc_get_prev_char_head(enc, sn->s, sn->end);
     if (p && p > sn->s) { /* can be split. */
       n = node_new_str(p, sn->end);
-      if ((sn->flag & NSTR_RAW) != 0)
+      if ((sn->flag & STRING_RAW) != 0)
         NSTRING_SET_RAW(n);
 
       sn->end = (UChar* )p;
@@ -1540,7 +1555,7 @@ onig_scan_unsigned_number(UChar** src, const UChar* end, OnigEncoding enc)
   PFETCH_READY;
 
   num = 0;
-  while (!PEND) {
+  while (! PEND) {
     PFETCH(c);
     if (ONIGENC_IS_CODE_DIGIT(enc, c)) {
       val = (unsigned int )DIGITVAL(c);
@@ -1596,7 +1611,7 @@ scan_unsigned_octal_number(UChar** src, UChar* end, int maxlen,
   PFETCH_READY;
 
   num = 0;
-  while (!PEND && maxlen-- != 0) {
+  while (! PEND && maxlen-- != 0) {
     PFETCH(c);
     if (ONIGENC_IS_CODE_DIGIT(enc, c) && c < '8') {
       val = ODIGITVAL(c);
@@ -1631,9 +1646,13 @@ new_code_range(BBuf** pbuf)
   BBuf* bbuf;
 
   bbuf = *pbuf = (BBuf* )xmalloc(sizeof(BBuf));
-  CHECK_NULL_RETURN_MEMERR(*pbuf);
-  r = BBUF_INIT(*pbuf, INIT_MULTI_BYTE_RANGE_SIZE);
-  if (r) return r;
+  CHECK_NULL_RETURN_MEMERR(bbuf);
+  r = BBUF_INIT(bbuf, INIT_MULTI_BYTE_RANGE_SIZE);
+  if (r != 0) {
+    xfree(bbuf);
+    *pbuf = 0;
+    return r;
+  }
 
   n = 0;
   BBUF_WRITE_CODE_POINT(bbuf, 0, n);
@@ -1654,7 +1673,7 @@ add_code_range_to_buf(BBuf** pbuf, OnigCodePoint from, OnigCodePoint to)
 
   if (IS_NULL(*pbuf)) {
     r = new_code_range(pbuf);
-    if (r) return r;
+    if (r != 0) return r;
     bbuf = *pbuf;
     n = 0;
   }
@@ -2069,27 +2088,27 @@ conv_backslash_value(OnigCodePoint c, ScanEnv* env)
 static int
 is_invalid_quantifier_target(Node* node)
 {
-  switch (NTYPE(node)) {
-  case NT_ANCHOR:
+  switch (NODE_TYPE(node)) {
+  case NODE_ANCHOR:
     return 1;
     break;
 
-  case NT_ENCLOSE:
+  case NODE_ENCLOSURE:
     /* allow enclosed elements */
-    /* return is_invalid_quantifier_target(NENCLOSE(node)->target); */
+    /* return is_invalid_quantifier_target(NODE_BODY(node)); */
     break;
 
-  case NT_LIST:
+  case NODE_LIST:
     do {
-      if (! is_invalid_quantifier_target(NCAR(node))) return 0;
-    } while (IS_NOT_NULL(node = NCDR(node)));
+      if (! is_invalid_quantifier_target(NODE_CAR(node))) return 0;
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     return 0;
     break;
 
-  case NT_ALT:
+  case NODE_ALT:
     do {
-      if (is_invalid_quantifier_target(NCAR(node))) return 1;
-    } while (IS_NOT_NULL(node = NCDR(node)));
+      if (is_invalid_quantifier_target(NODE_CAR(node))) return 1;
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
   default:
@@ -2100,7 +2119,7 @@ is_invalid_quantifier_target(Node* node)
 
 /* ?:0, *:1, +:2, ??:3, *?:4, +?:5 */
 static int
-popular_quantifier_num(QtfrNode* q)
+popular_quantifier_num(QuantNode* q)
 {
   if (q->greedy) {
     if (q->lower == 0) {
@@ -2147,10 +2166,10 @@ extern void
 onig_reduce_nested_quantifier(Node* pnode, Node* cnode)
 {
   int pnum, cnum;
-  QtfrNode *p, *c;
+  QuantNode *p, *c;
 
-  p = NQTFR(pnode);
-  c = NQTFR(cnode);
+  p = QUANT_(pnode);
+  c = QUANT_(cnode);
   pnum = popular_quantifier_num(p);
   cnum = popular_quantifier_num(c);
   if (pnum < 0 || cnum < 0) return ;
@@ -2160,36 +2179,36 @@ onig_reduce_nested_quantifier(Node* pnode, Node* cnode)
     *pnode = *cnode;
     break;
   case RQ_A:
-    p->target = c->target;
+    NODE_BODY(pnode) = NODE_BODY(cnode);
     p->lower  = 0;  p->upper = REPEAT_INFINITE;  p->greedy = 1;
     break;
   case RQ_AQ:
-    p->target = c->target;
+    NODE_BODY(pnode) = NODE_BODY(cnode);
     p->lower  = 0;  p->upper = REPEAT_INFINITE;  p->greedy = 0;
     break;
   case RQ_QQ:
-    p->target = c->target;
+    NODE_BODY(pnode) = NODE_BODY(cnode);
     p->lower  = 0;  p->upper = 1;  p->greedy = 0;
     break;
   case RQ_P_QQ:
-    p->target = cnode;
+    NODE_BODY(pnode) = cnode;
     p->lower  = 0;  p->upper = 1;  p->greedy = 0;
     c->lower  = 1;  c->upper = REPEAT_INFINITE;  c->greedy = 1;
     return ;
     break;
   case RQ_PQ_Q:
-    p->target = cnode;
+    NODE_BODY(pnode) = cnode;
     p->lower  = 0;  p->upper = 1;  p->greedy = 1;
     c->lower  = 1;  c->upper = REPEAT_INFINITE;  c->greedy = 0;
     return ;
     break;
   case RQ_ASIS:
-    p->target = cnode;
+    NODE_BODY(pnode) = cnode;
     return ;
     break;
   }
 
-  c->target = NULL_NODE;
+  NODE_BODY(cnode) = NULL_NODE;
   onig_node_free(cnode);
 }
 
@@ -2253,6 +2272,7 @@ typedef struct {
       UChar* name;
       UChar* name_end;
       int    gnum;
+      int    by_number;
     } call;
     struct {
       int ctype;
@@ -2441,19 +2461,27 @@ get_name_end_code_point(OnigCodePoint start)
   return (OnigCodePoint )0;
 }
 
+enum REF_NUM {
+  IS_NOT_NUM = 0,
+  IS_ABS_NUM = 1,
+  IS_REL_NUM = 2
+};
+
 #ifdef USE_NAMED_GROUP
 #ifdef USE_BACKREF_WITH_LEVEL
 /*
    \k<name+n>, \k<name-n>
    \k<num+n>,  \k<num-n>
    \k<-num+n>, \k<-num-n>
+   \k<+num+n>, \k<+num-n>
 */
 static int
 fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
-		      UChar** rname_end, ScanEnv* env,
-		      int* rback_num, int* rlevel)
+                      UChar** rname_end, ScanEnv* env,
+                      int* rback_num, int* rlevel, enum REF_NUM* num_type)
 {
-  int r, sign, is_num, exist_level;
+  int r, sign, exist_level;
+  int digit_count;
   OnigCodePoint end_code;
   OnigCodePoint c = 0;
   OnigEncoding enc = env->enc;
@@ -2463,12 +2491,14 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
   PFETCH_READY;
 
   *rback_num = 0;
-  is_num = exist_level = 0;
+  exist_level = 0;
+  *num_type = IS_NOT_NUM;
   sign = 1;
   pnum_head = *src;
 
   end_code = get_name_end_code_point(start_code);
 
+  digit_count = 0;
   name_end = end;
   r = 0;
   if (PEND) {
@@ -2480,13 +2510,19 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
       return ONIGERR_EMPTY_GROUP_NAME;
 
     if (ONIGENC_IS_CODE_DIGIT(enc, c)) {
-      is_num = 1;
+      *num_type = IS_ABS_NUM;
+      digit_count++;
     }
     else if (c == '-') {
-      is_num = 2;
+      *num_type = IS_REL_NUM;
       sign = -1;
       pnum_head = p;
     }
+    else if (c == '+') {
+      *num_type = IS_REL_NUM;
+      sign = 1;
+      pnum_head = p;
+    }
     else if (!ONIGENC_IS_CODE_WORD(enc, c)) {
       r = ONIGERR_INVALID_CHAR_IN_GROUP_NAME;
     }
@@ -2496,17 +2532,18 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
     name_end = p;
     PFETCH(c);
     if (c == end_code || c == ')' || c == '+' || c == '-') {
-      if (is_num == 2) 	r = ONIGERR_INVALID_GROUP_NAME;
+      if (*num_type != IS_NOT_NUM && digit_count == 0)
+        r = ONIGERR_INVALID_GROUP_NAME;
       break;
     }
 
-    if (is_num != 0) {
+    if (*num_type != IS_NOT_NUM) {
       if (ONIGENC_IS_CODE_DIGIT(enc, c)) {
-        is_num = 1;
+        digit_count++;
       }
       else {
         r = ONIGERR_INVALID_GROUP_NAME;
-        is_num = 0;
+        *num_type = IS_NOT_NUM;
       }
     }
     else if (!ONIGENC_IS_CODE_WORD(enc, c)) {
@@ -2539,16 +2576,20 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
     }
 
   err:
-    r = ONIGERR_INVALID_GROUP_NAME;
     name_end = end;
+  err2:
+    r = ONIGERR_INVALID_GROUP_NAME;
   }
 
  end:
   if (r == 0) {
-    if (is_num != 0) {
+    if (*num_type != IS_NOT_NUM) {
       *rback_num = onig_scan_unsigned_number(&pnum_head, name_end, enc);
       if (*rback_num < 0) return ONIGERR_TOO_BIG_NUMBER;
-      else if (*rback_num == 0) goto err;
+      else if (*rback_num == 0) {
+        if (*num_type == IS_REL_NUM)
+          goto err2;
+      }
 
       *rback_num *= sign;
     }
@@ -2570,9 +2611,11 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
 */
 static int
 fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
-	   UChar** rname_end, ScanEnv* env, int* rback_num, int ref)
+           UChar** rname_end, ScanEnv* env, int* rback_num,
+           enum REF_NUM* num_type, int ref)
 {
-  int r, is_num, sign;
+  int r, sign;
+  int digit_count;
   OnigCodePoint end_code;
   OnigCodePoint c = 0;
   OnigEncoding enc = env->enc;
@@ -2584,10 +2627,11 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
 
   end_code = get_name_end_code_point(start_code);
 
+  digit_count = 0;
   name_end = end;
   pnum_head = *src;
   r = 0;
-  is_num = 0;
+  *num_type = IS_NOT_NUM;
   sign = 1;
   if (PEND) {
     return ONIGERR_EMPTY_GROUP_NAME;
@@ -2599,21 +2643,30 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
 
     if (ONIGENC_IS_CODE_DIGIT(enc, c)) {
       if (ref == 1)
-        is_num = 1;
+        *num_type = IS_ABS_NUM;
       else {
         r = ONIGERR_INVALID_GROUP_NAME;
-        is_num = 0;
       }
+      digit_count++;
     }
     else if (c == '-') {
       if (ref == 1) {
-        is_num = 2;
+        *num_type = IS_REL_NUM;
         sign = -1;
         pnum_head = p;
       }
       else {
         r = ONIGERR_INVALID_GROUP_NAME;
-        is_num = 0;
+      }
+    }
+    else if (c == '+') {
+      if (ref == 1) {
+        *num_type = IS_REL_NUM;
+        sign = 1;
+        pnum_head = p;
+      }
+      else {
+        r = ONIGERR_INVALID_GROUP_NAME;
       }
     }
     else if (!ONIGENC_IS_CODE_WORD(enc, c)) {
@@ -2626,20 +2679,22 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
       name_end = p;
       PFETCH_S(c);
       if (c == end_code || c == ')') {
-        if (is_num == 2) 	r = ONIGERR_INVALID_GROUP_NAME;
+        if (*num_type != IS_NOT_NUM && digit_count == 0)
+          r = ONIGERR_INVALID_GROUP_NAME;
         break;
       }
 
-      if (is_num != 0) {
+      if (*num_type != IS_NOT_NUM) {
         if (ONIGENC_IS_CODE_DIGIT(enc, c)) {
-          is_num = 1;
+          digit_count++;
         }
         else {
           if (!ONIGENC_IS_CODE_WORD(enc, c))
             r = ONIGERR_INVALID_CHAR_IN_GROUP_NAME;
           else
             r = ONIGERR_INVALID_GROUP_NAME;
-          is_num = 0;
+
+          *num_type = IS_NOT_NUM;
         }
       }
       else {
@@ -2654,12 +2709,14 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
       name_end = end;
     }
 
-    if (is_num != 0) {
+    if (*num_type != IS_NOT_NUM) {
       *rback_num = onig_scan_unsigned_number(&pnum_head, name_end, enc);
       if (*rback_num < 0) return ONIGERR_TOO_BIG_NUMBER;
       else if (*rback_num == 0) {
-        r = ONIGERR_INVALID_GROUP_NAME;
-        goto err;
+        if (*num_type == IS_REL_NUM) {
+          r = ONIGERR_INVALID_GROUP_NAME;
+          goto err;
+        }
       }
 
       *rback_num *= sign;
@@ -2687,9 +2744,11 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
 #else
 static int
 fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
-	   UChar** rname_end, ScanEnv* env, int* rback_num, int ref)
+           UChar** rname_end, ScanEnv* env, int* rback_num,
+           enum REF_NUM* num_type, int ref)
 {
-  int r, is_num, sign;
+  int r, sign;
+  int digit_count;
   OnigCodePoint end_code;
   OnigCodePoint c = 0;
   UChar *name_end;
@@ -2702,10 +2761,11 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
 
   end_code = get_name_end_code_point(start_code);
 
+  digit_count = 0;
   *rname_end = name_end = end;
   r = 0;
   pnum_head = *src;
-  is_num = 0;
+  *num_type = IS_ABS_NUM;
   sign = 1;
 
   if (PEND) {
@@ -2717,37 +2777,61 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
       return ONIGERR_EMPTY_GROUP_NAME;
 
     if (ONIGENC_IS_CODE_DIGIT(enc, c)) {
-      is_num = 1;
+      *num_type = IS_ABS_NUM;
+      digit_count++;
     }
     else if (c == '-') {
-      is_num = 2;
-      sign = -1;
-      pnum_head = p;
+      if (ref == 1) {
+        *num_type = IS_REL_NUM;
+        sign = -1;
+        pnum_head = p;
+      }
+      else {
+        r = ONIGERR_INVALID_GROUP_NAME;
+      }
+    }
+    else if (c == '+') {
+      if (ref == 1) {
+        *num_type = IS_REL_NUM;
+        sign = 1;
+        pnum_head = p;
+      }
+      else {
+        r = ONIGERR_INVALID_GROUP_NAME;
+      }
     }
     else {
       r = ONIGERR_INVALID_CHAR_IN_GROUP_NAME;
     }
   }
 
-  while (!PEND) {
+  while (! PEND) {
     name_end = p;
 
     PFETCH(c);
     if (c == end_code || c == ')') break;
-    if (! ONIGENC_IS_CODE_DIGIT(enc, c))
+
+    if (ONIGENC_IS_CODE_DIGIT(enc, c))
+      digit_count++;
+    else
       r = ONIGERR_INVALID_CHAR_IN_GROUP_NAME;
   }
   if (r == 0 && c != end_code) {
     r = ONIGERR_INVALID_GROUP_NAME;
     name_end = end;
   }
+  if (r == 0 && digit_count == 0) {
+    r = ONIGERR_INVALID_GROUP_NAME;
+  }
 
   if (r == 0) {
     *rback_num = onig_scan_unsigned_number(&pnum_head, name_end, enc);
     if (*rback_num < 0) return ONIGERR_TOO_BIG_NUMBER;
     else if (*rback_num == 0) {
-      r = ONIGERR_INVALID_GROUP_NAME;
-      goto err;
+      if (*num_type == IS_REL_NUM) {
+        r = ONIGERR_INVALID_GROUP_NAME;
+        goto err;
+      }
     }
     *rback_num *= sign;
 
@@ -3418,7 +3502,7 @@ fetch_token(OnigToken* tok, UChar** src, UChar* end, ScanEnv* env)
       if (IS_SYNTAX_OP(syn, ONIG_SYN_OP_DECIMAL_BACKREF) && 
           (num <= env->num_mem || num <= 9)) { /* This spec. from GNU regex */
         if (IS_SYNTAX_BV(syn, ONIG_SYN_STRICT_CHECK_BACKREF)) {
-          if (num > env->num_mem || IS_NULL(SCANENV_MEM_NODES(env)[num]))
+          if (num > env->num_mem || IS_NULL(SCANENV_MEMENV(env)[num].node))
             return ONIGERR_INVALID_BACKREF;
         }
 
@@ -3466,30 +3550,31 @@ fetch_token(OnigToken* tok, UChar** src, UChar* end, ScanEnv* env)
           UChar* name_end;
           int* backs;
           int back_num;
+          enum REF_NUM num_type;
 
           prev = p;
 
 #ifdef USE_BACKREF_WITH_LEVEL
           name_end = NULL_UCHARP; /* no need. escape gcc warning. */
           r = fetch_name_with_level((OnigCodePoint )c, &p, end, &name_end,
-                                    env, &back_num, &tok->u.backref.level);
+                                 env, &back_num, &tok->u.backref.level, &num_type);
           if (r == 1) tok->u.backref.exist_level = 1;
           else        tok->u.backref.exist_level = 0;
 #else
-          r = fetch_name(&p, end, &name_end, env, &back_num, 1);
+          r = fetch_name(&p, end, &name_end, env, &back_num, &num_type, 1);
 #endif
           if (r < 0) return r;
 
-          if (back_num != 0) {
-            if (back_num < 0) {
-              back_num = BACKREF_REL_TO_ABS(back_num, env);
-              if (back_num <= 0)
-                return ONIGERR_INVALID_BACKREF;
+          if (num_type != IS_NOT_NUM) {
+            if (num_type == IS_REL_NUM) {
+              back_num = backref_rel_to_abs(back_num, env);
             }
+            if (back_num <= 0)
+              return ONIGERR_INVALID_BACKREF;
 
             if (IS_SYNTAX_BV(syn, ONIG_SYN_STRICT_CHECK_BACKREF)) {
               if (back_num > env->num_mem ||
-                  IS_NULL(SCANENV_MEM_NODES(env)[back_num]))
+                  IS_NULL(SCANENV_MEMENV(env)[back_num].node))
                 return ONIGERR_INVALID_BACKREF;
             }
             tok->type = TK_BACKREF;
@@ -3508,7 +3593,7 @@ fetch_token(OnigToken* tok, UChar** src, UChar* end, ScanEnv* env)
               int i;
               for (i = 0; i < num; i++) {
                 if (backs[i] > env->num_mem ||
-                    IS_NULL(SCANENV_MEM_NODES(env)[backs[i]]))
+                    IS_NULL(SCANENV_MEMENV(env)[backs[i]].node))
                   return ONIGERR_INVALID_BACKREF;
               }
             }
@@ -3538,15 +3623,30 @@ fetch_token(OnigToken* tok, UChar** src, UChar* end, ScanEnv* env)
         if (c == '<' || c == '\'') {
           int gnum;
           UChar* name_end;
+          enum REF_NUM num_type;
 
           prev = p;
-          r = fetch_name((OnigCodePoint )c, &p, end, &name_end, env, &gnum, 1);
+          r = fetch_name((OnigCodePoint )c, &p, end, &name_end, env,
+                         &gnum, &num_type, 1);
           if (r < 0) return r;
 
+          if (num_type != IS_NOT_NUM) {
+            if (num_type == IS_REL_NUM) {
+              gnum = backref_rel_to_abs(gnum, env);
+              if (gnum < 0)
+                return ONIGERR_UNDEFINED_GROUP_REFERENCE;
+            }
+            tok->u.call.by_number = 1;
+            tok->u.call.gnum      = gnum;
+          }
+          else {
+            tok->u.call.by_number = 0;
+            tok->u.call.gnum      = 0;
+          }
+
           tok->type = TK_CALL;
           tok->u.call.name     = prev;
           tok->u.call.name_end = name_end;
-          tok->u.call.gnum     = gnum;
         }
         else
           PUNFETCH;
@@ -4040,7 +4140,7 @@ parse_char_property(Node** np, OnigToken* tok, UChar** src, UChar* end,
 
   *np = node_new_cclass();
   CHECK_NULL_RETURN_MEMERR(*np);
-  cc = NCCLASS(*np);
+  cc = CCLASS_(*np);
   r = add_ctype_to_cc(cc, ctype, 0, env);
   if (r != 0) return r;
   if (tok->u.prop.not != 0) NCCLASS_SET_NOT(cc);
@@ -4080,9 +4180,7 @@ next_state_class(CClassNode* cc, OnigCodePoint* vs, enum CCVALTYPE* type,
     }
   }
 
-  if (*state != CCS_START)
-    *state = CCS_VALUE;
-
+  *state = CCS_VALUE;
   *type  = CCV_CLASS;
   return 0;
 }
@@ -4222,7 +4320,7 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
 
   *np = node = node_new_cclass();
   CHECK_NULL_RETURN_MEMERR(node);
-  cc = NCCLASS(node);
+  cc = CCLASS_(node);
 
   and_start = 0;
   state = CCS_START;
@@ -4335,7 +4433,7 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
 
     case TK_CHAR_TYPE:
       r = add_ctype_to_cc(cc, tok->u.prop.ctype, tok->u.prop.not, env);
-      if (r != 0) return r;
+      if (r != 0) goto err;
 
     next_class:
       r = next_state_class(cc, &vs, &val_type, &state, env);
@@ -4344,12 +4442,13 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
 
     case TK_CHAR_PROPERTY:
       {
-        int ctype;
-
-        ctype = fetch_char_property_to_ctype(&p, end, env);
-        if (ctype < 0) return ctype;
+        int ctype = fetch_char_property_to_ctype(&p, end, env);
+        if (ctype < 0) {
+          r = ctype;
+          goto err;
+        }
         r = add_ctype_to_cc(cc, ctype, tok->u.prop.not, env);
-        if (r != 0) return r;
+        if (r != 0) goto err;
         goto next_class;
       }
       break;
@@ -4369,6 +4468,12 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
           CC_ESC_WARN(env, (UChar* )"-");
           goto range_end_val;
         }
+
+        if (val_type == CCV_CLASS) {
+          r = ONIGERR_UNMATCHED_RANGE_SPECIFIER_IN_CHAR_CLASS;
+          goto err;
+        }
+
         state = CCS_RANGE;
       }
       else if (state == CCS_START) {
@@ -4418,10 +4523,10 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
           onig_node_free(anode);
           goto cc_open_err;
         }
-        acc = NCCLASS(anode);
+        acc = CCLASS_(anode);
         r = or_cclass(cc, acc, env->enc);
-
         onig_node_free(anode);
+
       cc_open_err:
         if (r != 0) goto err;
       }
@@ -4488,9 +4593,7 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
     NCCLASS_CLEAR_NOT(cc);
   if (IS_NCCLASS_NOT(cc) &&
       IS_SYNTAX_BV(env->syntax, ONIG_SYN_NOT_NEWLINE_IN_NEGATIVE_CC)) {
-    int is_empty;
-
-    is_empty = (IS_NULL(cc->mbuf) ? 1 : 0);
+    int is_empty = (IS_NULL(cc->mbuf) ? 1 : 0);
     if (is_empty != 0)
       BITSET_IS_EMPTY(cc->bs, is_empty);
 
@@ -4510,7 +4613,7 @@ parse_char_class(Node** np, OnigToken* tok, UChar** src, UChar* end,
   return 0;
 
  err:
-  if (cc != NCCLASS(*np))
+  if (cc != CCLASS_(*np))
     bbuf_free(cc->mbuf);
   return r;
 }
@@ -4519,18 +4622,17 @@ static int parse_subexp(Node** top, OnigToken* tok, int term,
 			UChar** src, UChar* end, ScanEnv* env);
 
 static int
-parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
+parse_enclosure(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
 	      ScanEnv* env)
 {
   int r, num;
   Node *target;
   OnigOptionType option;
   OnigCodePoint c;
-  OnigEncoding enc = env->enc;
-
 #ifdef USE_NAMED_GROUP
   int list_capture;
 #endif
+  OnigEncoding enc = env->enc;
 
   UChar* p = *src;
   PFETCH_READY;
@@ -4563,7 +4665,7 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
       *np = onig_node_new_anchor(ANCHOR_PREC_READ_NOT);
       break;
     case '>':            /* (?>...) stop backtrack */
-      *np = node_new_enclose(ENCLOSE_STOP_BACKTRACK);
+      *np = node_new_enclosure(ENCLOSURE_STOP_BACKTRACK);
       break;
 
 #ifdef USE_NAMED_GROUP
@@ -4588,6 +4690,7 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
         if (IS_SYNTAX_OP2(env->syntax, ONIG_SYN_OP2_QMARK_LT_NAMED_GROUP)) {
           UChar *name;
           UChar *name_end;
+          enum REF_NUM num_type;
 
           PUNFETCH;
           c = '<';
@@ -4597,21 +4700,22 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
 
         named_group2:
           name = p;
-          r = fetch_name((OnigCodePoint )c, &p, end, &name_end, env, &num, 0);
+          r = fetch_name((OnigCodePoint )c, &p, end, &name_end, env, &num,
+                         &num_type, 0);
           if (r < 0) return r;
 
           num = scan_env_add_mem_entry(env);
           if (num < 0) return num;
-          if (list_capture != 0 && num >= (int )BIT_STATUS_BITS_NUM)
+          if (list_capture != 0 && num >= (int )MEM_STATUS_BITS_NUM)
             return ONIGERR_GROUP_NUMBER_OVER_FOR_CAPTURE_HISTORY;
 
           r = name_add(env->reg, name, name_end, num, env);
           if (r != 0) return r;
-          *np = node_new_enclose_memory(env->option, 1);
+          *np = node_new_enclosure_memory(1);
           CHECK_NULL_RETURN_MEMERR(*np);
-          NENCLOSE(*np)->regnum = num;
+          ENCLOSURE_(*np)->m.regnum = num;
           if (list_capture != 0)
-            BIT_STATUS_ON_AT_SIMPLE(env->capture_history, num);
+            MEM_STATUS_ON_SIMPLE(env->capture_history, num);
           env->num_named++;
         }
         else {
@@ -4637,17 +4741,17 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
           PUNFETCH;
         }
 #endif
-        *np = node_new_enclose_memory(env->option, 0);
+        *np = node_new_enclosure_memory(0);
         CHECK_NULL_RETURN_MEMERR(*np);
         num = scan_env_add_mem_entry(env);
         if (num < 0) {
           return num;
         }
-        else if (num >= (int )BIT_STATUS_BITS_NUM) {
+        else if (num >= (int )MEM_STATUS_BITS_NUM) {
           return ONIGERR_GROUP_NUMBER_OVER_FOR_CAPTURE_HISTORY;
         }
-        NENCLOSE(*np)->regnum = num;
-        BIT_STATUS_ON_AT_SIMPLE(env->capture_history, num);
+        ENCLOSURE_(*np)->m.regnum = num;
+        MEM_STATUS_ON_SIMPLE(env->capture_history, num);
       }
       else {
         return ONIGERR_UNDEFINED_GROUP_OPTION;
@@ -4717,7 +4821,7 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
             }
             *np = node_new_option(option);
             CHECK_NULL_RETURN_MEMERR(*np);
-            NENCLOSE(*np)->target = target;
+            NODE_BODY(*np) = target;
             *src = p;
             return 0;
           }
@@ -4736,11 +4840,11 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
     if (ONIG_IS_OPTION_ON(env->option, ONIG_OPTION_DONT_CAPTURE_GROUP))
       goto group;
 
-    *np = node_new_enclose_memory(env->option, 0);
+    *np = node_new_enclosure_memory(0);
     CHECK_NULL_RETURN_MEMERR(*np);
     num = scan_env_add_mem_entry(env);
     if (num < 0) return num;
-    NENCLOSE(*np)->regnum = num;
+    ENCLOSURE_(*np)->m.regnum = num;
   }
 
   CHECK_NULL_RETURN_MEMERR(*np);
@@ -4752,13 +4856,12 @@ parse_enclose(Node** np, OnigToken* tok, int term, UChar** src, UChar* end,
     return r;
   }
 
-  if (NTYPE(*np) == NT_ANCHOR)
-    NANCHOR(*np)->target = target;
-  else {
-    NENCLOSE(*np)->target = target;
-    if (NENCLOSE(*np)->type == ENCLOSE_MEMORY) {
+  NODE_BODY(*np) = target;
+
+  if (NODE_TYPE(*np) == NODE_ENCLOSURE) {
+    if (ENCLOSURE_(*np)->type == ENCLOSURE_MEMORY) {
       /* Don't move this to previous of parse_subexp() */
-      r = scan_env_set_mem_node(env, NENCLOSE(*np)->regnum, *np);
+      r = scan_env_set_mem_node(env, ENCLOSURE_(*np)->m.regnum, *np);
       if (r != 0) return r;
     }
   }
@@ -4778,36 +4881,35 @@ static const char* ReduceQStr[] = {
 static int
 set_quantifier(Node* qnode, Node* target, int group, ScanEnv* env)
 {
-  QtfrNode* qn;
+  QuantNode* qn;
 
-  qn = NQTFR(qnode);
-  if (qn->lower == 1 && qn->upper == 1) {
+  qn = QUANT_(qnode);
+  if (qn->lower == 1 && qn->upper == 1)
     return 1;
-  }
 
-  switch (NTYPE(target)) {
-  case NT_STR:
+  switch (NODE_TYPE(target)) {
+  case NODE_STR:
     if (! group) {
-      StrNode* sn = NSTR(target);
+      StrNode* sn = STR_(target);
       if (str_node_can_be_split(sn, env->enc)) {
         Node* n = str_node_split_last_char(sn, env->enc);
         if (IS_NOT_NULL(n)) {
-          qn->target = n;
+          NODE_BODY(qnode) = n;
           return 2;
         }
       }
     }
     break;
 
-  case NT_QTFR:
+  case NODE_QUANT:
     { /* check redundant double repeat. */
       /* verbose warn (?:.?)? etc... but not warn (.?)? etc... */
-      QtfrNode* qnt   = NQTFR(target);
+      QuantNode* qnt   = QUANT_(target);
       int nestq_num   = popular_quantifier_num(qn);
       int targetq_num = popular_quantifier_num(qnt);
 
 #ifdef USE_WARNING_REDUNDANT_NESTED_REPEAT_OPERATOR
-      if (!IS_QUANTIFIER_BY_NUMBER(qn) && !IS_QUANTIFIER_BY_NUMBER(qnt) &&
+      if (! NODE_IS_BY_NUMBER(qnode) && ! NODE_IS_BY_NUMBER(target) &&
           IS_SYNTAX_BV(env->syntax, ONIG_SYN_WARN_REDUNDANT_NESTED_REPEAT)) {
         UChar buf[WARN_BUFSIZE];
 
@@ -4860,7 +4962,7 @@ set_quantifier(Node* qnode, Node* target, int group, ScanEnv* env)
     break;
   }
 
-  qn->target = target;
+  NODE_BODY(qnode) = target;
  q_exit:
   return 0;
 }
@@ -4971,7 +5073,7 @@ i_apply_case_fold(OnigCodePoint from, OnigCodePoint to[],
 
       *(iarg->ptail) = onig_node_new_alt(snode, NULL_NODE);
       CHECK_NULL_RETURN_MEMERR(*(iarg->ptail));
-      iarg->ptail = &(NCDR((*(iarg->ptail))));
+      iarg->ptail = &(NODE_CDR((*(iarg->ptail))));
     }
   }
 
@@ -4999,14 +5101,14 @@ parse_exp(Node** np, OnigToken* tok, int term,
   break;
 
   case TK_SUBEXP_OPEN:
-    r = parse_enclose(np, tok, TK_SUBEXP_CLOSE, src, end, env);
+    r = parse_enclosure(np, tok, TK_SUBEXP_CLOSE, src, end, env);
     if (r < 0) return r;
     if (r == 1) group = 1;
     else if (r == 2) { /* option only */
       Node* target;
       OnigOptionType prev = env->option;
 
-      env->option = NENCLOSE(*np)->option;
+      env->option = ENCLOSURE_(*np)->o.option;
       r = fetch_token(tok, src, end, env);
       if (r < 0) return r;
       r = parse_subexp(&target, tok, term, src, end, env);
@@ -5015,7 +5117,7 @@ parse_exp(Node** np, OnigToken* tok, int term,
         onig_node_free(target);
         return r;
       }
-      NENCLOSE(*np)->target = target;	
+      NODE_BODY(*np) = target;
       return tok->type;
     }
     break;
@@ -5057,7 +5159,7 @@ parse_exp(Node** np, OnigToken* tok, int term,
       len = 1;
       while (1) {
         if (len >= ONIGENC_MBC_MINLEN(env->enc)) {
-          if (len == enclen(env->enc, NSTR(*np)->s)) {//should not enclen_end()
+          if (len == enclen(env->enc, STR_(*np)->s)) {//should not enclen_end()
             r = fetch_token(tok, src, end, env);
             NSTRING_CLEAR_RAW(*np);
             goto string_end;
@@ -5072,8 +5174,8 @@ parse_exp(Node** np, OnigToken* tok, int term,
           int rem;
           if (len < ONIGENC_MBC_MINLEN(env->enc)) {
             rem = ONIGENC_MBC_MINLEN(env->enc) - len;
-            (void )node_str_head_pad(NSTR(*np), rem, (UChar )0);
-            if (len + rem == enclen(env->enc, NSTR(*np)->s)) {
+            (void )node_str_head_pad(STR_(*np), rem, (UChar )0);
+            if (len + rem == enclen(env->enc, STR_(*np)->s)) {
               NSTRING_CLEAR_RAW(*np);
               goto string_end;
             }
@@ -5138,7 +5240,7 @@ parse_exp(Node** np, OnigToken* tok, int term,
 
           *np = node_new_cclass();
           CHECK_NULL_RETURN_MEMERR(*np);
-          cc = NCCLASS(*np);
+          cc = CCLASS_(*np);
           add_ctype_to_cc(cc, tok->u.prop.ctype, 0, env);
           if (tok->u.prop.not != 0) NCCLASS_SET_NOT(cc);
         }
@@ -5163,7 +5265,7 @@ parse_exp(Node** np, OnigToken* tok, int term,
       r = parse_char_class(np, tok, src, end, env);
       if (r != 0) return r;
 
-      cc = NCCLASS(*np);
+      cc = CCLASS_(*np);
       if (IS_IGNORECASE(env->option)) {
         IApplyCaseFoldArg iarg;
 
@@ -5191,16 +5293,16 @@ parse_exp(Node** np, OnigToken* tok, int term,
     break;
 
   case TK_ANYCHAR:
-    *np = node_new_anychar();
+    *np = node_new_ctype(CTYPE_ANYCHAR, 0);
     CHECK_NULL_RETURN_MEMERR(*np);
     break;
 
   case TK_ANYCHAR_ANYTIME:
-    *np = node_new_anychar();
+    *np = node_new_ctype(CTYPE_ANYCHAR, 0);
     CHECK_NULL_RETURN_MEMERR(*np);
     qn = node_new_quantifier(0, REPEAT_INFINITE, 0);
     CHECK_NULL_RETURN_MEMERR(qn);
-    NQTFR(qn)->target = *np;
+    NODE_BODY(qn) = *np;
     *np = qn;
     break;
 
@@ -5222,14 +5324,13 @@ parse_exp(Node** np, OnigToken* tok, int term,
     {
       int gnum = tok->u.call.gnum;
 
-      if (gnum < 0) {
-        gnum = BACKREF_REL_TO_ABS(gnum, env);
-        if (gnum <= 0)
-          return ONIGERR_INVALID_BACKREF;
-      }
-      *np = node_new_call(tok->u.call.name, tok->u.call.name_end, gnum);
+      *np = node_new_call(tok->u.call.name, tok->u.call.name_end,
+                          gnum, tok->u.call.by_number);
       CHECK_NULL_RETURN_MEMERR(*np);
       env->num_call++;
+      if (tok->u.call.by_number != 0 && gnum == 0) {
+        env->has_call_zero = 1;
+      }
     }
     break;
 #endif
@@ -5271,7 +5372,7 @@ parse_exp(Node** np, OnigToken* tok, int term,
       qn = node_new_quantifier(tok->u.repeat.lower, tok->u.repeat.upper,
                                (r == TK_INTERVAL ? 1 : 0));
       CHECK_NULL_RETURN_MEMERR(qn);
-      NQTFR(qn)->greedy = tok->u.repeat.greedy;
+      QUANT_(qn)->greedy = tok->u.repeat.greedy;
       r = set_quantifier(qn, *targetp, group, env);
       if (r < 0) {
         onig_node_free(qn);
@@ -5280,12 +5381,12 @@ parse_exp(Node** np, OnigToken* tok, int term,
 
       if (tok->u.repeat.possessive != 0) {
         Node* en;
-        en = node_new_enclose(ENCLOSE_STOP_BACKTRACK);
+        en = node_new_enclosure(ENCLOSURE_STOP_BACKTRACK);
         if (IS_NULL(en)) {
           onig_node_free(qn);
           return ONIGERR_MEMORY;
         }
-        NENCLOSE(en)->target = qn;
+        NODE_BODY(en) = qn;
         qn = en;
       }
 
@@ -5303,12 +5404,12 @@ parse_exp(Node** np, OnigToken* tok, int term,
           onig_node_free(qn);
           return ONIGERR_MEMORY;
         }
-        tmp = NCDR(*targetp) = node_new_list(qn, NULL);
+        tmp = NODE_CDR(*targetp) = node_new_list(qn, NULL);
         if (IS_NULL(tmp)) {
           onig_node_free(qn);
           return ONIGERR_MEMORY;
         }
-        targetp = &(NCAR(tmp));
+        targetp = &(NODE_CAR(tmp));
       }
       goto re_entry;
     }
@@ -5336,7 +5437,7 @@ parse_branch(Node** top, OnigToken* tok, int term,
   }
   else {
     *top  = node_new_list(node, NULL);
-    headp = &(NCDR(*top));
+    headp = &(NODE_CDR(*top));
     while (r != TK_EOT && r != term && r != TK_ALT) {
       r = parse_exp(&node, tok, term, src, end, env);
       if (r < 0) {
@@ -5344,14 +5445,14 @@ parse_branch(Node** top, OnigToken* tok, int term,
         return r;
       }
 
-      if (NTYPE(node) == NT_LIST) {
+      if (NODE_TYPE(node) == NODE_LIST) {
         *headp = node;
-        while (IS_NOT_NULL(NCDR(node))) node = NCDR(node);
-        headp = &(NCDR(node));
+        while (IS_NOT_NULL(NODE_CDR(node))) node = NODE_CDR(node);
+        headp = &(NODE_CDR(node));
       }
       else {
         *headp = node_new_list(node, NULL);
-        headp = &(NCDR(*headp));
+        headp = &(NODE_CDR(*headp));
       }
     }
   }
@@ -5382,7 +5483,7 @@ parse_subexp(Node** top, OnigToken* tok, int term,
   }
   else if (r == TK_ALT) {
     *top  = onig_node_new_alt(node, NULL);
-    headp = &(NCDR(*top));
+    headp = &(NODE_CDR(*top));
     while (r == TK_ALT) {
       r = fetch_token(tok, src, end, env);
       if (r < 0) return r;
@@ -5392,7 +5493,7 @@ parse_subexp(Node** top, OnigToken* tok, int term,
         return r;
       }
       *headp = onig_node_new_alt(node, NULL);
-      headp = &(NCDR(*headp));
+      headp = &(NODE_CDR(*headp));
     }
 
     if (tok->type != (enum TokenSyms )term)
@@ -5421,12 +5522,35 @@ parse_regexp(Node** top, UChar** src, UChar* end, ScanEnv* env)
   if (r < 0) return r;
   r = parse_subexp(top, &tok, TK_EOT, src, end, env);
   if (r < 0) return r;
+
   return 0;
 }
 
+#ifdef USE_SUBEXP_CALL
+static int
+make_call_zero_body(Node* node, ScanEnv* env, Node** rnode)
+{
+  int r;
+
+  Node* x = node_new_enclosure_memory(0 /* 0: is not named */);
+  CHECK_NULL_RETURN_MEMERR(x);
+
+  NODE_BODY(x) = node;
+  ENCLOSURE_(x)->m.regnum = 0;
+  r = scan_env_set_mem_node(env, 0, x);
+  if (r != 0) {
+    onig_node_free(x);
+    return r;
+  }
+
+  *rnode = x;
+  return 0;
+}
+#endif
+
 extern int
-onig_parse_make_tree(Node** root, const UChar* pattern, const UChar* end,
-		     regex_t* reg, ScanEnv* env)
+onig_parse_tree(Node** root, const UChar* pattern, const UChar* end,
+                regex_t* reg, ScanEnv* env)
 {
   int r;
   UChar* p;
@@ -5451,6 +5575,19 @@ onig_parse_make_tree(Node** root, const UChar* pattern, const UChar* end,
 
   p = (UChar* )pattern;
   r = parse_regexp(root, &p, (UChar* )end, env);
+
+#ifdef USE_SUBEXP_CALL
+  if (r != 0) return r;
+
+  if (env->has_call_zero != 0) {
+    Node* zero_node;
+    r = make_call_zero_body(*root, env, &zero_node);
+    if (r != 0) return r;
+
+    *root = zero_node;
+  }
+#endif
+
   reg->num_mem = env->num_mem;
   return r;
 }
diff --git a/src/regparse.h b/src/regparse.h
index c9d1fe8..884f4d5 100644
--- a/src/regparse.h
+++ b/src/regparse.h
@@ -4,7 +4,7 @@
   regparse.h -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2007  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2017  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,88 +32,91 @@
 #include "regint.h"
 
 /* node type */
-#define NT_STR         0
-#define NT_CCLASS      1
-#define NT_CTYPE       2
-#define NT_CANY        3
-#define NT_BREF        4
-#define NT_QTFR        5
-#define NT_ENCLOSE     6
-#define NT_ANCHOR      7
-#define NT_LIST        8
-#define NT_ALT         9
-#define NT_CALL       10
+typedef enum {
+  NODE_STR       = 0,
+  NODE_CCLASS    = 1,
+  NODE_CTYPE     = 2,
+  NODE_BREF      = 3,
+  NODE_QUANT      = 4,
+  NODE_ENCLOSURE = 5,
+  NODE_ANCHOR    = 6,
+  NODE_LIST      = 7,
+  NODE_ALT       = 8,
+  NODE_CALL      = 9
+} NodeType;
 
 /* node type bit */
-#define NTYPE2BIT(type)      (1<<(type))
-
-#define BIT_NT_STR        NTYPE2BIT(NT_STR)
-#define BIT_NT_CCLASS     NTYPE2BIT(NT_CCLASS)
-#define BIT_NT_CTYPE      NTYPE2BIT(NT_CTYPE)
-#define BIT_NT_CANY       NTYPE2BIT(NT_CANY)
-#define BIT_NT_BREF       NTYPE2BIT(NT_BREF)
-#define BIT_NT_QTFR       NTYPE2BIT(NT_QTFR)
-#define BIT_NT_ENCLOSE    NTYPE2BIT(NT_ENCLOSE)
-#define BIT_NT_ANCHOR     NTYPE2BIT(NT_ANCHOR)
-#define BIT_NT_LIST       NTYPE2BIT(NT_LIST)
-#define BIT_NT_ALT        NTYPE2BIT(NT_ALT)
-#define BIT_NT_CALL       NTYPE2BIT(NT_CALL)
-
-#define IS_NODE_TYPE_SIMPLE(type) \
-  ((NTYPE2BIT(type) & (BIT_NT_STR | BIT_NT_CCLASS | BIT_NT_CTYPE |\
-                       BIT_NT_CANY | BIT_NT_BREF)) != 0)
-
-#define NTYPE(node)             ((node)->u.base.type)
-#define SET_NTYPE(node, ntype)   (node)->u.base.type = (ntype)
-
-#define NSTR(node)         (&((node)->u.str))
-#define NCCLASS(node)      (&((node)->u.cclass))
-#define NCTYPE(node)       (&((node)->u.ctype))
-#define NBREF(node)        (&((node)->u.bref))
-#define NQTFR(node)        (&((node)->u.qtfr))
-#define NENCLOSE(node)     (&((node)->u.enclose))
-#define NANCHOR(node)      (&((node)->u.anchor))
-#define NCONS(node)        (&((node)->u.cons))
-#define NCALL(node)        (&((node)->u.call))
-
-#define NCAR(node)         (NCONS(node)->car)
-#define NCDR(node)         (NCONS(node)->cdr)
-
+#define NODE_TYPE2BIT(type)      (1<<(type))
+
+#define BIT_NODE_STR        NODE_TYPE2BIT(NODE_STR)
+#define BIT_NODE_CCLASS     NODE_TYPE2BIT(NODE_CCLASS)
+#define BIT_NODE_CTYPE      NODE_TYPE2BIT(NODE_CTYPE)
+#define BIT_NODE_BREF       NODE_TYPE2BIT(NODE_BREF)
+#define BIT_NODE_QUANT       NODE_TYPE2BIT(NODE_QUANT)
+#define BIT_NODE_ENCLOSURE  NODE_TYPE2BIT(NODE_ENCLOSURE)
+#define BIT_NODE_ANCHOR     NODE_TYPE2BIT(NODE_ANCHOR)
+#define BIT_NODE_LIST       NODE_TYPE2BIT(NODE_LIST)
+#define BIT_NODE_ALT        NODE_TYPE2BIT(NODE_ALT)
+#define BIT_NODE_CALL       NODE_TYPE2BIT(NODE_CALL)
+
+#define NODE_IS_SIMPLE_TYPE(node) \
+  ((NODE_TYPE2BIT(NODE_TYPE(node)) & \
+    (BIT_NODE_STR | BIT_NODE_CCLASS | BIT_NODE_CTYPE | BIT_NODE_BREF)) != 0)
+
+#define NODE_TYPE(node)             ((node)->u.base.node_type)
+#define SET_NODE_TYPE(node, ntype)   (node)->u.base.node_type = (ntype)
+
+#define STR_(node)         (&((node)->u.str))
+#define CCLASS_(node)      (&((node)->u.cclass))
+#define CTYPE_(node)       (&((node)->u.ctype))
+#define BREF_(node)        (&((node)->u.bref))
+#define QUANT_(node)        (&((node)->u.quant))
+#define ENCLOSURE_(node)     (&((node)->u.enclosure))
+#define ANCHOR_(node)      (&((node)->u.anchor))
+#define CONS_(node)        (&((node)->u.cons))
+#define CALL_(node)        (&((node)->u.call))
+
+#define NODE_CAR(node)         (CONS_(node)->car)
+#define NODE_CDR(node)         (CONS_(node)->cdr)
+
+#define CTYPE_ANYCHAR      -1
+#define NODE_IS_ANYCHAR(node) \
+  (NODE_TYPE(node) == NODE_CTYPE && CTYPE_(node)->ctype == CTYPE_ANYCHAR)
 
 
 #define ANCHOR_ANYCHAR_STAR_MASK (ANCHOR_ANYCHAR_STAR | ANCHOR_ANYCHAR_STAR_ML)
 #define ANCHOR_END_BUF_MASK      (ANCHOR_END_BUF | ANCHOR_SEMI_END_BUF)
 
-#define ENCLOSE_MEMORY           (1<<0)
-#define ENCLOSE_OPTION           (1<<1)
-#define ENCLOSE_STOP_BACKTRACK   (1<<2)
+#define ENCLOSURE_MEMORY           (1<<0)
+#define ENCLOSURE_OPTION           (1<<1)
+#define ENCLOSURE_STOP_BACKTRACK   (1<<2)
 
 #define NODE_STR_MARGIN         16
 #define NODE_STR_BUF_SIZE       24  /* sizeof(CClassNode) - sizeof(int)*4 */
 #define NODE_BACKREFS_SIZE       6
 
-#define NSTR_RAW                (1<<0) /* by backslashed number */
-#define NSTR_AMBIG              (1<<1)
-#define NSTR_DONT_GET_OPT_INFO  (1<<2)
+#define STRING_RAW                (1<<0) /* by backslashed number */
+#define STRING_AMBIG              (1<<1)
+#define STRING_DONT_GET_OPT_INFO  (1<<2)
 
 #define NSTRING_LEN(node)             ((node)->u.str.end - (node)->u.str.s)
-#define NSTRING_SET_RAW(node)          (node)->u.str.flag |= NSTR_RAW
-#define NSTRING_CLEAR_RAW(node)        (node)->u.str.flag &= ~NSTR_RAW
-#define NSTRING_SET_AMBIG(node)        (node)->u.str.flag |= NSTR_AMBIG
+#define NSTRING_SET_RAW(node)          (node)->u.str.flag |= STRING_RAW
+#define NSTRING_CLEAR_RAW(node)        (node)->u.str.flag &= ~STRING_RAW
+#define NSTRING_SET_AMBIG(node)        (node)->u.str.flag |= STRING_AMBIG
 #define NSTRING_SET_DONT_GET_OPT_INFO(node) \
-  (node)->u.str.flag |= NSTR_DONT_GET_OPT_INFO
-#define NSTRING_IS_RAW(node)          (((node)->u.str.flag & NSTR_RAW)   != 0)
-#define NSTRING_IS_AMBIG(node)        (((node)->u.str.flag & NSTR_AMBIG) != 0)
+  (node)->u.str.flag |= STRING_DONT_GET_OPT_INFO
+#define NSTRING_IS_RAW(node)          (((node)->u.str.flag & STRING_RAW)   != 0)
+#define NSTRING_IS_AMBIG(node)        (((node)->u.str.flag & STRING_AMBIG) != 0)
 #define NSTRING_IS_DONT_GET_OPT_INFO(node) \
-  (((node)->u.str.flag & NSTR_DONT_GET_OPT_INFO) != 0)
+  (((node)->u.str.flag & STRING_DONT_GET_OPT_INFO) != 0)
 
 #define BACKREFS_P(br) \
   (IS_NOT_NULL((br)->back_dynamic) ? (br)->back_dynamic : (br)->back_static);
 
-#define NQ_TARGET_ISNOT_EMPTY     0
-#define NQ_TARGET_IS_EMPTY        1
-#define NQ_TARGET_IS_EMPTY_MEM    2
-#define NQ_TARGET_IS_EMPTY_REC    3
+#define QUANT_BODY_IS_NOT_EMPTY    0
+#define QUANT_BODY_IS_EMPTY        1
+#define QUANT_BODY_IS_EMPTY_MEM    2
+#define QUANT_BODY_IS_EMPTY_REC    3
 
 /* status bits */
 #define NST_MIN_FIXED             (1<<0)
@@ -121,44 +124,56 @@
 #define NST_CLEN_FIXED            (1<<2)
 #define NST_MARK1                 (1<<3)
 #define NST_MARK2                 (1<<4)
-#define NST_MEM_BACKREFED         (1<<5)
-#define NST_STOP_BT_SIMPLE_REPEAT (1<<6)
-#define NST_RECURSION             (1<<7)
-#define NST_CALLED                (1<<8)
-#define NST_ADDR_FIXED            (1<<9)
-#define NST_NAMED_GROUP           (1<<10)
-#define NST_NAME_REF              (1<<11)
-#define NST_IN_REPEAT             (1<<12) /* STK_REPEAT is nested in stack. */
+#define NST_STOP_BT_SIMPLE_REPEAT (1<<5)
+#define NST_RECURSION             (1<<6)
+#define NST_CALLED                (1<<7)
+#define NST_ADDR_FIXED            (1<<8)
+#define NST_NAMED_GROUP           (1<<9)
+#define NST_IN_REAL_REPEAT        (1<<10) /* STK_REPEAT is nested in stack. */
+#define NST_IN_ZERO_REPEAT        (1<<11) /* (....){0} */
+#define NST_IN_MULTI_ENTRY        (1<<12)
 #define NST_NEST_LEVEL            (1<<13)
 #define NST_BY_NUMBER             (1<<14) /* {n,m} */
+#define NST_BY_NAME               (1<<15) /* backref by name */
+#define NST_BACKREF               (1<<16)
+
+
+#define NODE_STATUS(node)           (((Node* )node)->u.base.status)
+#define NODE_STATUS_ADD(node,f)     (NODE_STATUS(node) |= (f))
+#define NODE_STATUS_REMOVE(node,f)  (NODE_STATUS(node) &= ~(f))
+
+#define NODE_IS_BY_NUMBER(node)       ((NODE_STATUS(node) & NST_BY_NUMBER) != 0)
+#define NODE_IS_IN_REAL_REPEAT(node)  ((NODE_STATUS(node) & NST_IN_REAL_REPEAT) != 0)
+#define NODE_IS_CALLED(node)          ((NODE_STATUS(node) & NST_CALLED)    != 0)
+#define NODE_IS_IN_MULTI_ENTRY(node)  ((NODE_STATUS(node) & NST_IN_MULTI_ENTRY) != 0)
+#define NODE_IS_RECURSION(node)       ((NODE_STATUS(node) & NST_RECURSION) != 0)
+#define NODE_IS_IN_ZERO_REPEAT(node)  ((NODE_STATUS(node) & NST_IN_ZERO_REPEAT) != 0)
+#define NODE_IS_NAMED_GROUP(node)     ((NODE_STATUS(node) & NST_NAMED_GROUP) != 0)
+#define NODE_IS_ADDR_FIXED(node)      ((NODE_STATUS(node) & NST_ADDR_FIXED)  != 0)
+#define NODE_IS_CLEN_FIXED(node)      ((NODE_STATUS(node) & NST_CLEN_FIXED)  != 0)
+#define NODE_IS_MIN_FIXED(node)       ((NODE_STATUS(node) & NST_MIN_FIXED)   != 0)
+#define NODE_IS_MAX_FIXED(node)       ((NODE_STATUS(node) & NST_MAX_FIXED)   != 0)
+#define NODE_IS_MARK1(node)           ((NODE_STATUS(node) & NST_MARK1)       != 0)
+#define NODE_IS_MARK2(node)           ((NODE_STATUS(node) & NST_MARK2)       != 0)
+#define NODE_IS_NEST_LEVEL(node)      ((NODE_STATUS(node) & NST_NEST_LEVEL)  != 0)
+#define NODE_IS_BY_NAME(node)         ((NODE_STATUS(node) & NST_BY_NAME)     != 0)
+#define NODE_IS_BACKREF(node)         ((NODE_STATUS(node) & NST_BACKREF)     != 0)
+#define NODE_IS_STOP_BT_SIMPLE_REPEAT(node) \
+    ((NODE_STATUS(node) & NST_STOP_BT_SIMPLE_REPEAT) != 0)
+
+#define NODE_BODY(node)           ((node)->u.base.body)
+#define NODE_QUANT_BODY(node)      ((node)->body)
+#define NODE_ENCLOSURE_BODY(node)   ((node)->body)
+#define NODE_CALL_BODY(node)      ((node)->body)
+#define NODE_ANCHOR_BODY(node)    ((node)->body)
 
-#define SET_ENCLOSE_STATUS(node,f)      (node)->u.enclose.state |=  (f)
-#define CLEAR_ENCLOSE_STATUS(node,f)    (node)->u.enclose.state &= ~(f)
-
-#define IS_ENCLOSE_CALLED(en)          (((en)->state & NST_CALLED)        != 0)
-#define IS_ENCLOSE_ADDR_FIXED(en)      (((en)->state & NST_ADDR_FIXED)    != 0)
-#define IS_ENCLOSE_RECURSION(en)       (((en)->state & NST_RECURSION)     != 0)
-#define IS_ENCLOSE_MARK1(en)           (((en)->state & NST_MARK1)         != 0)
-#define IS_ENCLOSE_MARK2(en)           (((en)->state & NST_MARK2)         != 0)
-#define IS_ENCLOSE_MIN_FIXED(en)       (((en)->state & NST_MIN_FIXED)     != 0)
-#define IS_ENCLOSE_MAX_FIXED(en)       (((en)->state & NST_MAX_FIXED)     != 0)
-#define IS_ENCLOSE_CLEN_FIXED(en)      (((en)->state & NST_CLEN_FIXED)    != 0)
-#define IS_ENCLOSE_STOP_BT_SIMPLE_REPEAT(en) \
-    (((en)->state & NST_STOP_BT_SIMPLE_REPEAT) != 0)
-#define IS_ENCLOSE_NAMED_GROUP(en)     (((en)->state & NST_NAMED_GROUP)   != 0)
-
-#define SET_CALL_RECURSION(node)       (node)->u.call.state |= NST_RECURSION
-#define IS_CALL_RECURSION(cn)          (((cn)->state & NST_RECURSION)  != 0)
-#define IS_CALL_NAME_REF(cn)           (((cn)->state & NST_NAME_REF)   != 0)
-#define IS_BACKREF_NAME_REF(bn)        (((bn)->state & NST_NAME_REF)   != 0)
-#define IS_BACKREF_NEST_LEVEL(bn)      (((bn)->state & NST_NEST_LEVEL) != 0)
-#define IS_QUANTIFIER_IN_REPEAT(qn)    (((qn)->state & NST_IN_REPEAT)  != 0)
-#define IS_QUANTIFIER_BY_NUMBER(qn)    (((qn)->state & NST_BY_NUMBER)  != 0)
 
 #define CALLNODE_REFNUM_UNDEF  -1
 
 typedef struct {
-  NodeBase base;
+  NodeType node_type;
+  int status;
+
   UChar* s;
   UChar* end;
   unsigned int flag;
@@ -167,35 +182,54 @@ typedef struct {
 } StrNode;
 
 typedef struct {
-  NodeBase base;
-  int state;
-  struct _Node* target;
+  NodeType node_type;
+  int status;
+
+  unsigned int flags;
+  BitSet bs;
+  BBuf*  mbuf;   /* multi-byte info or NULL */
+} CClassNode;
+
+typedef struct {
+  NodeType node_type;
+  int status;
+  struct _Node* body;
+
   int lower;
   int upper;
   int greedy;
-  int target_empty_info;
+  int body_empty_info;
   struct _Node* head_exact;
   struct _Node* next_head_exact;
   int is_refered;     /* include called node. don't eliminate even if {0} */
 #ifdef USE_COMBINATION_EXPLOSION_CHECK
   int comb_exp_check_num;  /* 1,2,3...: check,  0: no check  */
 #endif
-} QtfrNode;
+} QuantNode;
 
 typedef struct {
-  NodeBase base;
-  int state;
+  NodeType node_type;
+  int status;
+  struct _Node* body;
+
   int type;
-  int regnum;
-  OnigOptionType option;
-  struct _Node*  target;
-  AbsAddrType    call_addr;
+  union {
+    struct {
+      int regnum;
+      AbsAddrType called_addr;
+      int entry_count;
+      int called_state;
+    } m;
+    struct {
+      OnigOptionType option;
+    } o;
+  };
   /* for multiple call reference */
   OnigLen min_len; /* min length (byte) */
   OnigLen max_len; /* max length (byte) */
   int char_len;         /* character length  */
   int opt_count;        /* referenced count in optimize_node_left() */
-} EncloseNode;
+} EnclosureNode;
 
 #ifdef USE_SUBEXP_CALL
 
@@ -211,20 +245,23 @@ typedef struct {
 } UnsetAddrList;
 
 typedef struct {
-  NodeBase base;
-  int     state;
+  NodeType node_type;
+  int status;
+  struct _Node* body; /* to EnclosureNode : ENCLOSURE_MEMORY */
+
+  int     by_number;
   int     group_num;
   UChar*  name;
   UChar*  name_end;
-  struct _Node*  target;  /* EncloseNode : ENCLOSE_MEMORY */
-  UnsetAddrList* unset_addr_list;
+  int     entry_count;
 } CallNode;
 
 #endif
 
 typedef struct {
-  NodeBase base;
-  int  state;
+  NodeType node_type;
+  int status;
+
   int  back_num;
   int  back_static[NODE_BACKREFS_SIZE];
   int* back_dynamic;
@@ -232,37 +269,48 @@ typedef struct {
 } BRefNode;
 
 typedef struct {
-  NodeBase base;
+  NodeType node_type;
+  int status;
+  struct _Node* body;
+
   int type;
-  struct _Node* target;
   int char_len;
 } AnchorNode;
 
 typedef struct {
-  NodeBase base;
+  NodeType node_type;
+  int status;
+
   struct _Node* car;
   struct _Node* cdr;
 } ConsAltNode;
 
 typedef struct {
-  NodeBase base;
+  NodeType node_type;
+  int status;
+
   int ctype;
   int not;
 } CtypeNode;
 
 typedef struct _Node {
   union {
-    NodeBase     base;
-    StrNode      str;
-    CClassNode   cclass;
-    QtfrNode     qtfr;
-    EncloseNode  enclose;
-    BRefNode     bref;
-    AnchorNode   anchor;
-    ConsAltNode  cons;
-    CtypeNode    ctype;
+    struct {
+      NodeType node_type;
+      int status;
+      struct _Node* body;
+    } base;
+
+    StrNode       str;
+    CClassNode    cclass;
+    QuantNode     quant;
+    EnclosureNode enclosure;
+    BRefNode      bref;
+    AnchorNode    anchor;
+    ConsAltNode   cons;
+    CtypeNode     ctype;
 #ifdef USE_SUBEXP_CALL
-    CallNode     call;
+    CallNode      call;
 #endif
   } u;
 } Node;
@@ -270,20 +318,28 @@ typedef struct _Node {
 
 #define NULL_NODE  ((Node* )0)
 
-#define SCANENV_MEMNODES_SIZE               8
-#define SCANENV_MEM_NODES(senv)   \
- (IS_NOT_NULL((senv)->mem_nodes_dynamic) ? \
-    (senv)->mem_nodes_dynamic : (senv)->mem_nodes_static)
+#define SCANENV_MEMENV_SIZE               8
+#define SCANENV_MEMENV(senv) \
+ (IS_NOT_NULL((senv)->mem_env_dynamic) ? \
+    (senv)->mem_env_dynamic : (senv)->mem_env_static)
+
+typedef struct {
+  Node* node;
+#if 0
+  int in;
+  int recursion;
+#endif
+} MemEnv;
 
 typedef struct {
   OnigOptionType   option;
   OnigCaseFoldType case_fold_flag;
   OnigEncoding     enc;
   OnigSyntaxType*  syntax;
-  BitStatusType    capture_history;
-  BitStatusType    bt_mem_start;
-  BitStatusType    bt_mem_end;
-  BitStatusType    backrefed_mem;
+  MemStatusType    capture_history;
+  MemStatusType    bt_mem_start;
+  MemStatusType    bt_mem_end;
+  MemStatusType    backrefed_mem;
   UChar*           pattern;
   UChar*           pattern_end;
   UChar*           error;
@@ -292,14 +348,15 @@ typedef struct {
   int              num_call;
 #ifdef USE_SUBEXP_CALL
   UnsetAddrList*   unset_addr_list;
+  int              has_call_zero;
 #endif
   int              num_mem;
 #ifdef USE_NAMED_GROUP
   int              num_named;
 #endif
   int              mem_alloc;
-  Node*            mem_nodes_static[SCANENV_MEMNODES_SIZE];
-  Node**           mem_nodes_dynamic;
+  MemEnv            mem_env_static[SCANENV_MEMENV_SIZE];
+  MemEnv*           mem_env_dynamic;
 #ifdef USE_COMBINATION_EXPLOSION_CHECK
   int num_comb_exp_check;
   int comb_exp_max_regnum;
@@ -331,7 +388,7 @@ extern void   onig_node_conv_to_str_node P_((Node* node, int raw));
 extern int    onig_node_str_cat P_((Node* node, const UChar* s, const UChar* end));
 extern int    onig_node_str_set P_((Node* node, const UChar* s, const UChar* end));
 extern void   onig_node_free P_((Node* node));
-extern Node*  onig_node_new_enclose P_((int type));
+extern Node*  onig_node_new_enclosure P_((int type));
 extern Node*  onig_node_new_anchor P_((int type));
 extern Node*  onig_node_new_str P_((const UChar* s, const UChar* end));
 extern Node*  onig_node_new_list P_((Node* left, Node* right));
@@ -339,8 +396,9 @@ extern Node*  onig_node_list_add P_((Node* list, Node* x));
 extern Node*  onig_node_new_alt P_((Node* left, Node* right));
 extern void   onig_node_str_clear P_((Node* node));
 extern int    onig_names_free P_((regex_t* reg));
-extern int    onig_parse_make_tree P_((Node** root, const UChar* pattern, const UChar* end, regex_t* reg, ScanEnv* env));
+extern int    onig_parse_tree P_((Node** root, const UChar* pattern, const UChar* end, regex_t* reg, ScanEnv* env));
 extern int    onig_free_shared_cclass_table P_((void));
+extern int    onig_is_code_in_cc P_((OnigEncoding enc, OnigCodePoint code, CClassNode* cc));
 
 #ifdef ONIG_DEBUG
 #ifdef USE_NAMED_GROUP
diff --git a/src/st.c b/src/st.c
index d4fe867..e5fd1a1 100644
--- a/src/st.c
+++ b/src/st.c
@@ -108,17 +108,16 @@ new_size(size)
 
 #if 0
     for (i=3; i<31; i++) {
-	if ((1<<i) > size) return 1<<i;
+      if ((1<<i) > size) return 1<<i;
     }
     return -1;
 #else
     int newsize;
 
     for (i = 0, newsize = MINSIZE;
-	 i < (int )(sizeof(primes)/sizeof(primes[0]));
-	 i++, newsize <<= 1)
-    {
-	if (newsize > size) return primes[i];
+         i < (int )(sizeof(primes)/sizeof(primes[0]));
+         i++, newsize <<= 1) {
+      if (newsize > size) return primes[i];
     }
     /* Ran out of polynomials */
     return -1;			/* should raise exception */
@@ -145,82 +144,82 @@ st_init_table_with_size(type, size)
     struct st_hash_type *type;
     int size;
 {
-    st_table *tbl;
+  st_table *tbl;
 
 #ifdef HASH_LOG
-    if (init_st == 0) {
-	init_st = 1;
-	atexit(stat_col);
-    }
+  if (init_st == 0) {
+    init_st = 1;
+    atexit(stat_col);
+  }
 #endif
 
-    size = new_size(size);	/* round up to prime number */
+  size = new_size(size);	/* round up to prime number */
 
-    tbl = alloc(st_table);
-    if (tbl == 0) return 0;
+  tbl = alloc(st_table);
+  if (tbl == 0) return 0;
 
-    tbl->type = type;
-    tbl->num_entries = 0;
-    tbl->num_bins = size;
-    tbl->bins = (st_table_entry **)Calloc(size, sizeof(st_table_entry*));
-    if (tbl->bins == 0) {
-      free(tbl);
-      return 0;
-    }
+  tbl->type = type;
+  tbl->num_entries = 0;
+  tbl->num_bins = size;
+  tbl->bins = (st_table_entry **)Calloc(size, sizeof(st_table_entry*));
+  if (tbl->bins == 0) {
+    free(tbl);
+    return 0;
+  }
 
-    return tbl;
+  return tbl;
 }
 
 st_table*
 st_init_table(type)
     struct st_hash_type *type;
 {
-    return st_init_table_with_size(type, 0);
+  return st_init_table_with_size(type, 0);
 }
 
 st_table*
 st_init_numtable(void)
 {
-    return st_init_table(&type_numhash);
+  return st_init_table(&type_numhash);
 }
 
 st_table*
 st_init_numtable_with_size(size)
     int size;
 {
-    return st_init_table_with_size(&type_numhash, size);
+  return st_init_table_with_size(&type_numhash, size);
 }
 
 st_table*
 st_init_strtable(void)
 {
-    return st_init_table(&type_strhash);
+  return st_init_table(&type_strhash);
 }
 
 st_table*
 st_init_strtable_with_size(size)
     int size;
 {
-    return st_init_table_with_size(&type_strhash, size);
+  return st_init_table_with_size(&type_strhash, size);
 }
 
 void
 st_free_table(table)
     st_table *table;
 {
-    register st_table_entry *ptr, *next;
-    int i;
+  register st_table_entry *ptr, *next;
+  int i;
 
-    for(i = 0; i < table->num_bins; i++) {
-	ptr = table->bins[i];
-	while (ptr != 0) {
+  for(i = 0; i < table->num_bins; i++) {
+    ptr = table->bins[i];
+    while (ptr != 0) {
 	    next = ptr->next;
 	    free(ptr);
 	    ptr = next;
-	}
     }
-    free(table->bins);
-    free(table);
+  }
+  free(table->bins);
+  free(table);
 }
 
 #define PTR_NOT_EQUAL(table, ptr, hash_val, key) \
@@ -236,187 +235,186 @@ st_free_table(table)
     bin_pos = hash_val%(table)->num_bins;\
     ptr = (table)->bins[bin_pos];\
     if (PTR_NOT_EQUAL(table, ptr, hash_val, key)) {\
-	COLLISION;\
-	while (PTR_NOT_EQUAL(table, ptr->next, hash_val, key)) {\
-	    ptr = ptr->next;\
-	}\
-	ptr = ptr->next;\
+      COLLISION;\
+      while (PTR_NOT_EQUAL(table, ptr->next, hash_val, key)) {\
+        ptr = ptr->next;\
+      }\
+      ptr = ptr->next;\
     }\
 } while (0)
 
 int
 st_lookup(table, key, value)
-    st_table *table;
-    register st_data_t key;
-    st_data_t *value;
+     st_table *table;
+     register st_data_t key;
+     st_data_t *value;
 {
-    unsigned int hash_val, bin_pos;
-    register st_table_entry *ptr;
+  unsigned int hash_val, bin_pos;
+  register st_table_entry *ptr;
 
-    hash_val = do_hash(key, table);
-    FIND_ENTRY(table, ptr, hash_val, bin_pos);
+  hash_val = do_hash(key, table);
+  FIND_ENTRY(table, ptr, hash_val, bin_pos);
 
-    if (ptr == 0) {
-	return 0;
-    }
-    else {
-	if (value != 0)  *value = ptr->record;
-	return 1;
-    }
+  if (ptr == 0) {
+    return 0;
+  }
+  else {
+    if (value != 0)  *value = ptr->record;
+    return 1;
+  }
 }
 
-#define ADD_DIRECT(table, key, value, hash_val, bin_pos)\
+#define ADD_DIRECT(table, key, value, hash_val, bin_pos, ret) \
 do {\
-    st_table_entry *entry;\
-    if (table->num_entries/(table->num_bins) > ST_DEFAULT_MAX_DENSITY) {\
-	rehash(table);\
-        bin_pos = hash_val % table->num_bins;\
-    }\
-    \
-    entry = alloc(st_table_entry);\
-    \
-    entry->hash = hash_val;\
-    entry->key = key;\
-    entry->record = value;\
-    entry->next = table->bins[bin_pos];\
-    table->bins[bin_pos] = entry;\
-    table->num_entries++;\
+  st_table_entry *entry;\
+  if (table->num_entries/(table->num_bins) > ST_DEFAULT_MAX_DENSITY) {\
+    rehash(table);\
+    bin_pos = hash_val % table->num_bins;\
+  }\
+  entry = alloc(st_table_entry);\
+  if (IS_NULL(entry)) return ret;\
+  entry->hash = hash_val;\
+  entry->key = key;\
+  entry->record = value;\
+  entry->next = table->bins[bin_pos];\
+  table->bins[bin_pos] = entry;\
+  table->num_entries++;\
 } while (0)
 
 int
 st_insert(table, key, value)
-    register st_table *table;
-    register st_data_t key;
-    st_data_t value;
+     register st_table *table;
+     register st_data_t key;
+     st_data_t value;
 {
-    unsigned int hash_val, bin_pos;
-    register st_table_entry *ptr;
+  unsigned int hash_val, bin_pos;
+  register st_table_entry *ptr;
 
-    hash_val = do_hash(key, table);
-    FIND_ENTRY(table, ptr, hash_val, bin_pos);
+  hash_val = do_hash(key, table);
+  FIND_ENTRY(table, ptr, hash_val, bin_pos);
 
-    if (ptr == 0) {
-	ADD_DIRECT(table, key, value, hash_val, bin_pos);
-	return 0;
-    }
-    else {
-	ptr->record = value;
-	return 1;
-    }
+  if (ptr == 0) {
+    ADD_DIRECT(table, key, value, hash_val, bin_pos, ONIGERR_MEMORY);
+    return 0;
+  }
+  else {
+    ptr->record = value;
+    return 1;
+  }
 }
 
 void
 st_add_direct(table, key, value)
-    st_table *table;
-    st_data_t key;
-    st_data_t value;
+     st_table *table;
+     st_data_t key;
+     st_data_t value;
 {
-    unsigned int hash_val, bin_pos;
+  unsigned int hash_val, bin_pos;
 
-    hash_val = do_hash(key, table);
-    bin_pos = hash_val % table->num_bins;
-    ADD_DIRECT(table, key, value, hash_val, bin_pos);
+  hash_val = do_hash(key, table);
+  bin_pos = hash_val % table->num_bins;
+  ADD_DIRECT(table, key, value, hash_val, bin_pos,);
 }
 
 static void
 rehash(table)
-    register st_table *table;
+     register st_table *table;
 {
-    register st_table_entry *ptr, *next, **new_bins;
-    int i, old_num_bins = table->num_bins, new_num_bins;
-    unsigned int hash_val;
-
-    new_num_bins = new_size(old_num_bins+1);
-    new_bins = (st_table_entry**)Calloc(new_num_bins, sizeof(st_table_entry*));
-    if (new_bins == 0) {
-      return ;
-    }
-
-    for(i = 0; i < old_num_bins; i++) {
-	ptr = table->bins[i];
-	while (ptr != 0) {
+  register st_table_entry *ptr, *next, **new_bins;
+  int i, old_num_bins = table->num_bins, new_num_bins;
+  unsigned int hash_val;
+
+  new_num_bins = new_size(old_num_bins+1);
+  new_bins = (st_table_entry**)Calloc(new_num_bins, sizeof(st_table_entry*));
+  if (new_bins == 0) {
+    return ;
+  }
+
+  for(i = 0; i < old_num_bins; i++) {
+    ptr = table->bins[i];
+    while (ptr != 0) {
 	    next = ptr->next;
 	    hash_val = ptr->hash % new_num_bins;
 	    ptr->next = new_bins[hash_val];
 	    new_bins[hash_val] = ptr;
 	    ptr = next;
-	}
     }
-    free(table->bins);
-    table->num_bins = new_num_bins;
-    table->bins = new_bins;
+  }
+  free(table->bins);
+  table->num_bins = new_num_bins;
+  table->bins = new_bins;
 }
 
 st_table*
 st_copy(old_table)
-    st_table *old_table;
+     st_table *old_table;
 {
-    st_table *new_table;
-    st_table_entry *ptr, *entry;
-    int i, num_bins = old_table->num_bins;
+  st_table *new_table;
+  st_table_entry *ptr, *entry;
+  int i, num_bins = old_table->num_bins;
 
-    new_table = alloc(st_table);
-    if (new_table == 0) {
-	return 0;
-    }
+  new_table = alloc(st_table);
+  if (new_table == 0) {
+    return 0;
+  }
 
-    *new_table = *old_table;
-    new_table->bins = (st_table_entry**)
-	Calloc((unsigned)num_bins, sizeof(st_table_entry*));
+  *new_table = *old_table;
+  new_table->bins = (st_table_entry**)
+    Calloc((unsigned)num_bins, sizeof(st_table_entry*));
 
-    if (new_table->bins == 0) {
-	free(new_table);
-	return 0;
-    }
+  if (new_table->bins == 0) {
+    free(new_table);
+    return 0;
+  }
 
-    for(i = 0; i < num_bins; i++) {
-	new_table->bins[i] = 0;
-	ptr = old_table->bins[i];
-	while (ptr != 0) {
+  for(i = 0; i < num_bins; i++) {
+    new_table->bins[i] = 0;
+    ptr = old_table->bins[i];
+    while (ptr != 0) {
 	    entry = alloc(st_table_entry);
 	    if (entry == 0) {
-		free(new_table->bins);
-		free(new_table);
-		return 0;
+        free(new_table->bins);
+        free(new_table);
+        return 0;
 	    }
 	    *entry = *ptr;
 	    entry->next = new_table->bins[i];
 	    new_table->bins[i] = entry;
 	    ptr = ptr->next;
-	}
     }
-    return new_table;
+  }
+  return new_table;
 }
 
 int
 st_delete(table, key, value)
-    register st_table *table;
-    register st_data_t *key;
-    st_data_t *value;
+     register st_table *table;
+     register st_data_t *key;
+     st_data_t *value;
 {
-    unsigned int hash_val;
-    st_table_entry *tmp;
-    register st_table_entry *ptr;
+  unsigned int hash_val;
+  st_table_entry *tmp;
+  register st_table_entry *ptr;
 
-    hash_val = do_hash_bin(*key, table);
-    ptr = table->bins[hash_val];
+  hash_val = do_hash_bin(*key, table);
+  ptr = table->bins[hash_val];
 
-    if (ptr == 0) {
-	if (value != 0) *value = 0;
-	return 0;
-    }
-
-    if (EQUAL(table, *key, ptr->key)) {
-	table->bins[hash_val] = ptr->next;
-	table->num_entries--;
-	if (value != 0) *value = ptr->record;
-	*key = ptr->key;
-	free(ptr);
-	return 1;
-    }
-
-    for(; ptr->next != 0; ptr = ptr->next) {
-	if (EQUAL(table, ptr->next->key, *key)) {
+  if (ptr == 0) {
+    if (value != 0) *value = 0;
+    return 0;
+  }
+
+  if (EQUAL(table, *key, ptr->key)) {
+    table->bins[hash_val] = ptr->next;
+    table->num_entries--;
+    if (value != 0) *value = ptr->record;
+    *key = ptr->key;
+    free(ptr);
+    return 1;
+  }
+
+  for(; ptr->next != 0; ptr = ptr->next) {
+    if (EQUAL(table, ptr->next->key, *key)) {
 	    tmp = ptr->next;
 	    ptr->next = ptr->next->next;
 	    table->num_entries--;
@@ -424,41 +422,41 @@ st_delete(table, key, value)
 	    *key = tmp->key;
 	    free(tmp);
 	    return 1;
-	}
     }
+  }
 
-    return 0;
+  return 0;
 }
 
 int
 st_delete_safe(table, key, value, never)
-    register st_table *table;
-    register st_data_t *key;
-    st_data_t *value;
-    st_data_t never;
+     register st_table *table;
+     register st_data_t *key;
+     st_data_t *value;
+     st_data_t never;
 {
-    unsigned int hash_val;
-    register st_table_entry *ptr;
+  unsigned int hash_val;
+  register st_table_entry *ptr;
 
-    hash_val = do_hash_bin(*key, table);
-    ptr = table->bins[hash_val];
+  hash_val = do_hash_bin(*key, table);
+  ptr = table->bins[hash_val];
 
-    if (ptr == 0) {
-	if (value != 0) *value = 0;
-	return 0;
-    }
+  if (ptr == 0) {
+    if (value != 0) *value = 0;
+    return 0;
+  }
 
-    for(; ptr != 0; ptr = ptr->next) {
-	if ((ptr->key != never) && EQUAL(table, ptr->key, *key)) {
+  for(; ptr != 0; ptr = ptr->next) {
+    if ((ptr->key != never) && EQUAL(table, ptr->key, *key)) {
 	    table->num_entries--;
 	    *key = ptr->key;
 	    if (value != 0) *value = ptr->record;
 	    ptr->key = ptr->record = never;
 	    return 1;
-	}
     }
+  }
 
-    return 0;
+  return 0;
 }
 
 static int
@@ -476,114 +474,114 @@ delete_never(key, value, never)
 
 void
 st_cleanup_safe(table, never)
-    st_table *table;
-    st_data_t never;
+     st_table *table;
+     st_data_t never;
 {
-    int num_entries = table->num_entries;
+  int num_entries = table->num_entries;
 
-    st_foreach(table, delete_never, never);
-    table->num_entries = num_entries;
+  st_foreach(table, delete_never, never);
+  table->num_entries = num_entries;
 }
 
 int
 st_foreach(table, func, arg)
-    st_table *table;
-    int (*func)();
-    st_data_t arg;
+     st_table *table;
+     int (*func)();
+     st_data_t arg;
 {
-    st_table_entry *ptr, *last, *tmp;
-    enum st_retval retval;
-    int i;
+  st_table_entry *ptr, *last, *tmp;
+  enum st_retval retval;
+  int i;
 
-    for(i = 0; i < table->num_bins; i++) {
-	last = 0;
-	for(ptr = table->bins[i]; ptr != 0;) {
+  for(i = 0; i < table->num_bins; i++) {
+    last = 0;
+    for(ptr = table->bins[i]; ptr != 0;) {
 	    retval = (*func)(ptr->key, ptr->record, arg);
 	    switch (retval) {
 	    case ST_CHECK:	/* check if hash is modified during iteration */
-	        tmp = 0;
-		if (i < table->num_bins) {
-		    for (tmp = table->bins[i]; tmp; tmp=tmp->next) {
-			if (tmp == ptr) break;
-		    }
-		}
-		if (!tmp) {
-		    /* call func with error notice */
-		    return 1;
-		}
-		/* fall through */
+        tmp = 0;
+        if (i < table->num_bins) {
+          for (tmp = table->bins[i]; tmp; tmp=tmp->next) {
+            if (tmp == ptr) break;
+          }
+        }
+        if (!tmp) {
+          /* call func with error notice */
+          return 1;
+        }
+        /* fall through */
 	    case ST_CONTINUE:
-		last = ptr;
-		ptr = ptr->next;
-		break;
+        last = ptr;
+        ptr = ptr->next;
+        break;
 	    case ST_STOP:
-	        return 0;
+        return 0;
 	    case ST_DELETE:
-		tmp = ptr;
-		if (last == 0) {
-		    table->bins[i] = ptr->next;
-		}
-		else {
-		    last->next = ptr->next;
-		}
-		ptr = ptr->next;
-		free(tmp);
-		table->num_entries--;
+        tmp = ptr;
+        if (last == 0) {
+          table->bins[i] = ptr->next;
+        }
+        else {
+          last->next = ptr->next;
+        }
+        ptr = ptr->next;
+        free(tmp);
+        table->num_entries--;
 	    }
-	}
     }
-    return 0;
+  }
+  return 0;
 }
 
 static int
 strhash(string)
-    register const char *string;
+     register const char *string;
 {
-    register int c;
+  register int c;
 
 #ifdef HASH_ELFHASH
-    register unsigned int h = 0, g;
+  register unsigned int h = 0, g;
 
-    while ((c = *string++) != '\0') {
-	h = ( h << 4 ) + c;
-	if ( g = h & 0xF0000000 )
+  while ((c = *string++) != '\0') {
+    h = ( h << 4 ) + c;
+    if ( g = h & 0xF0000000 )
 	    h ^= g >> 24;
-	h &= ~g;
-    }
-    return h;
+    h &= ~g;
+  }
+  return h;
 #elif HASH_PERL
-    register int val = 0;
+  register int val = 0;
 
-    while ((c = *string++) != '\0') {
-	val += c;
-	val += (val << 10);
-	val ^= (val >> 6);
-    }
-    val += (val << 3);
-    val ^= (val >> 11);
+  while ((c = *string++) != '\0') {
+    val += c;
+    val += (val << 10);
+    val ^= (val >> 6);
+  }
+  val += (val << 3);
+  val ^= (val >> 11);
 
-    return val + (val << 15);
+  return val + (val << 15);
 #else
-    register int val = 0;
+  register int val = 0;
 
-    while ((c = *string++) != '\0') {
-	val = val*997 + c;
-    }
+  while ((c = *string++) != '\0') {
+    val = val*997 + c;
+  }
 
-    return val + (val>>5);
+  return val + (val>>5);
 #endif
 }
 
 static int
 numcmp(x, y)
-    long x, y;
+     long x, y;
 {
-    return x != y;
+  return x != y;
 }
 
 static int
 numhash(n)
-    long n;
+     long n;
 {
-    return n;
+  return n;
 }
diff --git a/src/unicode.c b/src/unicode.c
index 8812ca2..5b6b3e7 100644
--- a/src/unicode.c
+++ b/src/unicode.c
@@ -2,7 +2,7 @@
   unicode.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2016  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2017  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -91,6 +91,7 @@ extern int
 onig_unicode_define_user_property(const char* name, OnigCodePoint* ranges)
 {
   UserDefinedPropertyValue* e;
+  int r;
   int i;
   int n;
   int len;
@@ -130,9 +131,10 @@ onig_unicode_define_user_property(const char* name, OnigCodePoint* ranges)
   e = UserDefinedPropertyRanges + UserDefinedPropertyNum;
   e->ctype = CODE_RANGES_NUM + UserDefinedPropertyNum;
   e->ranges = ranges;
-  onig_st_insert_strend(UserDefinedPropertyTable,
-                        (const UChar* )s, (const UChar* )s + n,
-                        (hash_data_type )((void* )e));
+  r = onig_st_insert_strend(UserDefinedPropertyTable,
+                            (const UChar* )s, (const UChar* )s + n,
+                            (hash_data_type )((void* )e));
+  if (r < 0) return r;
 
   UserDefinedPropertyNum++;
   return 0;
@@ -162,7 +164,7 @@ onigenc_unicode_is_code_ctype(OnigCodePoint code, unsigned int ctype)
 
 
 extern int
-onigenc_unicode_ctype_code_range(int ctype, const OnigCodePoint* ranges[])
+onigenc_unicode_ctype_code_range(OnigCtype ctype, const OnigCodePoint* ranges[])
 {
   if (ctype >= CODE_RANGES_NUM) {
     int index = ctype - CODE_RANGES_NUM;