regcomp.c

/**********************************************************************
  regcomp.c -  Oniguruma (regular expression library)
**********************************************************************/
/*-
 * Copyright (c) 2002-2008  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "mruby.h"
#include <string.h>
#include "regparse.h"
#ifdef ENABLE_REGEXP

OnigCaseFoldType OnigDefaultCaseFoldFlag = ONIGENC_CASE_FOLD_MIN;

extern OnigCaseFoldType
onig_get_default_case_fold_flag(void)
{
  return OnigDefaultCaseFoldFlag;
}

extern int
onig_set_default_case_fold_flag(OnigCaseFoldType case_fold_flag)
{
  OnigDefaultCaseFoldFlag = case_fold_flag;
  return 0;
}


#ifndef PLATFORM_UNALIGNED_WORD_ACCESS
static unsigned char PadBuf[WORD_ALIGNMENT_SIZE];
#endif

static UChar*
str_dup(UChar* s, UChar* end)
{
  ptrdiff_t len = end - s;

  if (len > 0) {
    UChar* r = (UChar* )xmalloc(len + 1);
    CHECK_NULL_RETURN(r);
    xmemcpy(r, s, len);
    r[len] = (UChar )0;
    return r;
  }
  else return NULL;
}

static void
swap_node(Node* a, Node* b)
{
  Node c;
  c = *a; *a = *b; *b = c;

  if (NTYPE(a) == NT_STR) {
    StrNode* sn = NSTR(a);
    if (sn->capa == 0) {
      size_t len = sn->end - sn->s;
      sn->s   = sn->buf;
      sn->end = sn->s + len;
    }
  }

  if (NTYPE(b) == NT_STR) {
    StrNode* sn = NSTR(b);
    if (sn->capa == 0) {
      size_t len = sn->end - sn->s;
      sn->s   = sn->buf;
      sn->end = sn->s + len;
    }
  }
}

static OnigDistance
distance_add(OnigDistance d1, OnigDistance d2)
{
  if (d1 == ONIG_INFINITE_DISTANCE || d2 == ONIG_INFINITE_DISTANCE)
    return ONIG_INFINITE_DISTANCE;
  else {
    if (d1 <= ONIG_INFINITE_DISTANCE - d2) return d1 + d2;
    else return ONIG_INFINITE_DISTANCE;
  }
}

static OnigDistance
distance_multiply(OnigDistance d, int m)
{
  if (m == 0) return 0;

  if (d < ONIG_INFINITE_DISTANCE / m)
    return d * m;
  else
    return ONIG_INFINITE_DISTANCE;
}

static int
bitset_is_empty(BitSetRef bs)
{
  int i;
  for (i = 0; i < (int )BITSET_SIZE; i++) {
    if (bs[i] != 0) return 0;
  }
  return 1;
}

#ifdef ONIG_DEBUG
static int
bitset_on_num(BitSetRef bs)
{
  int i, n;

  n = 0;
  for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
    if (BITSET_AT(bs, i)) n++;
  }
  return n;
}
#endif

extern int
onig_bbuf_init(BBuf* buf, int size)
{
  if (size <= 0) {
    size   = 0;
    buf->p = NULL;
  }
  else {
    buf->p = (UChar* )xmalloc(size);
    if (IS_NULL(buf->p)) return(ONIGERR_MEMORY);
  }

  buf->alloc = size;
  buf->used  = 0;
  return 0;
}


#ifdef USE_SUBEXP_CALL

static int
unset_addr_list_init(UnsetAddrList* uslist, int size)
{
  UnsetAddr* p;

  p = (UnsetAddr* )xmalloc(sizeof(UnsetAddr)* size);
  CHECK_NULL_RETURN_MEMERR(p);
  uslist->num   = 0;
  uslist->alloc = size;
  uslist->us    = p;
  return 0;
}

static void
unset_addr_list_end(UnsetAddrList* uslist)
{
  if (IS_NOT_NULL(uslist->us))
    xfree(uslist->us);
}

static int
unset_addr_list_add(UnsetAddrList* uslist, 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);
    CHECK_NULL_RETURN_MEMERR(p);
    uslist->alloc = size;
    uslist->us    = p;
  }

  uslist->us[uslist->num].offset = offset;
  uslist->us[uslist->num].target = node;
  uslist->num++;
  return 0;
}
#endif /* USE_SUBEXP_CALL */


static int
add_opcode(regex_t* reg, int opcode)
{
  BBUF_ADD1(reg, opcode);
  return 0;
}

#ifdef USE_COMBINATION_EXPLOSION_CHECK
static int
add_state_check_num(regex_t* reg, int num)
{
  StateCheckNumType n = (StateCheckNumType )num;

  BBUF_ADD(reg, &n, SIZE_STATE_CHECK_NUM);
  return 0;
}
#endif

static int
add_rel_addr(regex_t* reg, int addr)
{
  RelAddrType ra = (RelAddrType )addr;

  BBUF_ADD(reg, &ra, SIZE_RELADDR);
  return 0;
}

static int
add_abs_addr(regex_t* reg, int addr)
{
  AbsAddrType ra = (AbsAddrType )addr;

  BBUF_ADD(reg, &ra, SIZE_ABSADDR);
  return 0;
}

static int
add_length(regex_t* reg, int len)
{
  LengthType l = (LengthType )len;

  BBUF_ADD(reg, &l, SIZE_LENGTH);
  return 0;
}

static int
add_mem_num(regex_t* reg, int num)
{
  MemNumType n = (MemNumType )num;

  BBUF_ADD(reg, &n, SIZE_MEMNUM);
  return 0;
}

static int
add_pointer(regex_t* reg, void* addr)
{
  PointerType ptr = (PointerType )addr;

  BBUF_ADD(reg, &ptr, SIZE_POINTER);
  return 0;
}

static int
add_option(regex_t* reg, OnigOptionType option)
{
  BBUF_ADD(reg, &option, SIZE_OPTION);
  return 0;
}

static int
add_opcode_rel_addr(regex_t* reg, int opcode, int addr)
{
  int r;

  r = add_opcode(reg, opcode);
  if (r) return r;
  r = add_rel_addr(reg, addr);
  return r;
}

static int
add_bytes(regex_t* reg, UChar* bytes, int len)
{
  BBUF_ADD(reg, bytes, len);
  return 0;
}

static int
add_bitset(regex_t* reg, BitSetRef bs)
{
  BBUF_ADD(reg, bs, SIZE_BITSET);
  return 0;
}

static int
add_opcode_option(regex_t* reg, int opcode, OnigOptionType option)
{
  int r;

  r = add_opcode(reg, opcode);
  if (r) 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);


#define IS_NEED_STR_LEN_OP_EXACT(op) \
   ((op) == OP_EXACTN    || (op) == OP_EXACTMB2N ||\
    (op) == OP_EXACTMB3N || (op) == OP_EXACTMBN  || (op) == OP_EXACTN_IC)

static int
select_str_opcode(int mb_len, int str_len, int ignore_case)
{
  int op;

  if (ignore_case) {
    switch (str_len) {
    case 1:  op = OP_EXACT1_IC; break;
    default: op = OP_EXACTN_IC; break;
    }
  }
  else {
    switch (mb_len) {
    case 1:
      switch (str_len) {
      case 1:  op = OP_EXACT1; break;
      case 2:  op = OP_EXACT2; break;
      case 3:  op = OP_EXACT3; break;
      case 4:  op = OP_EXACT4; break;
      case 5:  op = OP_EXACT5; break;
      default: op = OP_EXACTN; break;
      }
      break;

    case 2:
      switch (str_len) {
      case 1:  op = OP_EXACTMB2N1; break;
      case 2:  op = OP_EXACTMB2N2; break;
      case 3:  op = OP_EXACTMB2N3; break;
      default: op = OP_EXACTMB2N;  break;
      }
      break;

    case 3:
      op = OP_EXACTMB3N;
      break;

    default:
      op = OP_EXACTMBN;
      break;
    }
  }
  return op;
}

static int
compile_tree_empty_check(Node* node, regex_t* reg, int empty_info)
{
  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;
    r = add_mem_num(reg, reg->num_null_check); /* NULL CHECK ID */
    if (r) return r;
    reg->num_null_check++;
  }

  r = compile_tree(node, reg);
  if (r) 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 (r) return r;
    r = add_mem_num(reg, saved_num_null_check); /* NULL CHECK ID */
  }
  return r;
}

#ifdef USE_SUBEXP_CALL
static int
compile_call(CallNode* node, regex_t* reg)
{
  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;
  r = add_abs_addr(reg, 0 /*dummy addr.*/);
  return r;
}
#endif

static int
compile_tree_n_times(Node* node, int n, regex_t* reg)
{
  int i, r;

  for (i = 0; i < n; i++) {
    r = compile_tree(node, reg);
    if (r) return r;
  }
  return 0;
}

static int
add_compile_string_length(UChar* s ARG_UNUSED, int mb_len, OnigDistance str_len,
                          regex_t* reg ARG_UNUSED, int ignore_case)
{
  int len;
  int op = select_str_opcode(mb_len, str_len, ignore_case);

  len = SIZE_OPCODE;

  if (op == OP_EXACTMBN)  len += SIZE_LENGTH;
  if (IS_NEED_STR_LEN_OP_EXACT(op))
    len += SIZE_LENGTH;

  len += mb_len * str_len;
  return len;
}

static int
add_compile_string(UChar* s, int mb_len, int str_len,
                   regex_t* reg, int ignore_case)
{
  int op = select_str_opcode(mb_len, str_len, ignore_case);
  add_opcode(reg, op);

  if (op == OP_EXACTMBN)
    add_length(reg, mb_len);

  if (IS_NEED_STR_LEN_OP_EXACT(op)) {
    if (op == OP_EXACTN_IC)
      add_length(reg, mb_len * str_len);
    else
      add_length(reg, str_len);
  }

  add_bytes(reg, s, mb_len * str_len);
  return 0;
}


static int
compile_length_string_node(Node* node, regex_t* reg)
{
  int rlen, r, len, prev_len, slen, ambig;
  OnigEncoding enc = reg->enc;
  UChar *p, *prev;
  StrNode* sn;

  sn = NSTR(node);
  if (sn->end <= sn->s)
    return 0;

  ambig = NSTRING_IS_AMBIG(node);

  p = prev = sn->s;
  prev_len = enclen(enc, p, sn->end);
  p += prev_len;
  slen = 1;
  rlen = 0;

  for (; p < sn->end; ) {
    len = enclen(enc, p, sn->end);
    if (len == prev_len) {
      slen++;
    }
    else {
      r = add_compile_string_length(prev, prev_len, slen, reg, ambig);
      rlen += r;
      prev = p;
      slen = 1;
      prev_len = len;
    }
    p += len;
  }
  r = add_compile_string_length(prev, prev_len, slen, reg, ambig);
  rlen += r;
  return rlen;
}

static int
compile_length_string_raw_node(StrNode* sn, regex_t* reg)
{
  if (sn->end <= sn->s)
    return 0;

  return add_compile_string_length(sn->s, 1 /* sb */, sn->end - sn->s, reg, 0);
}

static int
compile_string_node(Node* node, regex_t* reg)
{
  int r, len, prev_len, slen, ambig;
  OnigEncoding enc = reg->enc;
  UChar *p, *prev, *end;
  StrNode* sn;

  sn = NSTR(node);
  if (sn->end <= sn->s)
    return 0;

  end = sn->end;
  ambig = NSTRING_IS_AMBIG(node);

  p = prev = sn->s;
  prev_len = enclen(enc, p, end);
  p += prev_len;
  slen = 1;

  for (; p < end; ) {
    len = enclen(enc, p, end);
    if (len == prev_len) {
      slen++;
    }
    else {
      r = add_compile_string(prev, prev_len, slen, reg, ambig);
      if (r) return r;

      prev  = p;
      slen  = 1;
      prev_len = len;
    }

    p += len;
  }
  return add_compile_string(prev, prev_len, slen, reg, ambig);
}

static int
compile_string_raw_node(StrNode* sn, regex_t* reg)
{
  if (sn->end <= sn->s)
    return 0;

  return add_compile_string(sn->s, 1 /* sb */, sn->end - sn->s, reg, 0);
}

static int
add_multi_byte_cclass(BBuf* mbuf, regex_t* reg)
{
#ifdef PLATFORM_UNALIGNED_WORD_ACCESS
  add_length(reg, mbuf->used);
  return add_bytes(reg, mbuf->p, mbuf->used);
#else
  int r, pad_size;
  UChar* p = BBUF_GET_ADD_ADDRESS(reg) + SIZE_LENGTH;

  GET_ALIGNMENT_PAD_SIZE(p, pad_size);
  add_length(reg, mbuf->used + (WORD_ALIGNMENT_SIZE - 1));
  if (pad_size != 0) add_bytes(reg, PadBuf, pad_size);

  r = add_bytes(reg, mbuf->p, mbuf->used);

  /* padding for return value from compile_length_cclass_node() to be fix. */
  pad_size = (WORD_ALIGNMENT_SIZE - 1) - pad_size;
  if (pad_size != 0) add_bytes(reg, PadBuf, pad_size);
  return r;
#endif
}

static int
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;
  }
  else {
    if (ONIGENC_MBC_MINLEN(reg->enc) > 1 || bitset_is_empty(cc->bs)) {
      len = SIZE_OPCODE;
    }
    else {
      len = SIZE_OPCODE + SIZE_BITSET;
    }
#ifdef PLATFORM_UNALIGNED_WORD_ACCESS
    len += SIZE_LENGTH + cc->mbuf->used;
#else
    len += SIZE_LENGTH + cc->mbuf->used + (WORD_ALIGNMENT_SIZE - 1);
#endif
  }

  return len;
}

static int
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);
    else
      add_opcode(reg, OP_CCLASS);

    r = add_bitset(reg, cc->bs);
  }
  else {
    if (ONIGENC_MBC_MINLEN(reg->enc) > 1 || bitset_is_empty(cc->bs)) {
      if (IS_NCCLASS_NOT(cc))
        add_opcode(reg, OP_CCLASS_MB_NOT);
      else
        add_opcode(reg, OP_CCLASS_MB);

      r = add_multi_byte_cclass(cc->mbuf, reg);
    }
    else {
      if (IS_NCCLASS_NOT(cc))
        add_opcode(reg, OP_CCLASS_MIX_NOT);
      else
        add_opcode(reg, OP_CCLASS_MIX);

      r = add_bitset(reg, cc->bs);
      if (r) return r;
      r = add_multi_byte_cclass(cc->mbuf, reg);
    }
  }

  return r;
}

static int
entry_repeat_range(regex_t* reg, int id, int lower, int upper)
{
#define REPEAT_RANGE_ALLOC  4

  OnigRepeatRange* p;

  if (reg->repeat_range_alloc == 0) {
    p = (OnigRepeatRange* )xmalloc(sizeof(OnigRepeatRange) * REPEAT_RANGE_ALLOC);
    CHECK_NULL_RETURN_MEMERR(p);
    reg->repeat_range = p;
    reg->repeat_range_alloc = REPEAT_RANGE_ALLOC;
  }
  else if (reg->repeat_range_alloc <= id) {
    int n;
    n = reg->repeat_range_alloc + REPEAT_RANGE_ALLOC;
    p = (OnigRepeatRange* )xrealloc(reg->repeat_range,
                                    sizeof(OnigRepeatRange) * n);
    CHECK_NULL_RETURN_MEMERR(p);
    reg->repeat_range = p;
    reg->repeat_range_alloc = n;
  }
  else {
    p = reg->repeat_range;
  }

  p[id].lower = lower;
  p[id].upper = (IS_REPEAT_INFINITE(upper) ? 0x7fffffff : upper);
  return 0;
}

static int
compile_range_repeat_node(QtfrNode* qn, int target_len, int empty_info,
                          regex_t* reg)
{
  int r;
  int num_repeat = reg->num_repeat;

  r = add_opcode(reg, qn->greedy ? OP_REPEAT : OP_REPEAT_NG);
  if (r) return r;
  r = add_mem_num(reg, num_repeat); /* OP_REPEAT ID */
  reg->num_repeat++;
  if (r) return r;
  r = add_rel_addr(reg, target_len + SIZE_OP_REPEAT_INC);
  if (r) return r;

  r = entry_repeat_range(reg, num_repeat, qn->lower, qn->upper);
  if (r) return r;

  r = compile_tree_empty_check(qn->target, reg, empty_info);
  if (r) return r;

  if (
#ifdef USE_SUBEXP_CALL
      reg->num_call > 0 ||
#endif
      IS_QUANTIFIER_IN_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;
  r = add_mem_num(reg, num_repeat); /* OP_REPEAT ID */
  return r;
}

static int
is_anychar_star_quantifier(QtfrNode* qn)
{
  if (qn->greedy && IS_REPEAT_INFINITE(qn->upper) &&
      NTYPE(qn->target) == NT_CANY)
    return 1;
  else
    return 0;
}

#define QUANTIFIER_EXPAND_LIMIT_SIZE   50
#define CKN_ON   (ckn > 0)

#ifdef USE_COMBINATION_EXPLOSION_CHECK

static int
compile_length_quantifier_node(QtfrNode* 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);

  if (tlen < 0) return tlen;

  ckn = ((reg->num_comb_exp_check > 0) ? qn->comb_exp_check_num : 0);

  cklen = (CKN_ON ? SIZE_STATE_CHECK_NUM: 0);

  /* anychar repeat */
  if (NTYPE(qn->target) == NT_CANY) {
    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;
      else
        return SIZE_OP_ANYCHAR_STAR + tlen * qn->lower + cklen;
    }
  }

  if (empty_info != 0)
    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
  else
    mod_tlen = tlen;

  if (infinite && qn->lower <= 1) {
    if (qn->greedy) {
      if (qn->lower == 1)
        len = SIZE_OP_JUMP;
      else
        len = 0;

      len += SIZE_OP_PUSH + cklen + mod_tlen + SIZE_OP_JUMP;
    }
    else {
      if (qn->lower == 0)
        len = SIZE_OP_JUMP;
      else
        len = 0;

      len += mod_tlen + SIZE_OP_PUSH + cklen;
    }
  }
  else if (qn->upper == 0) {
    if (qn->is_refered != 0) /* /(?<n>..){0}/ */
      len = SIZE_OP_JUMP + tlen;
    else
      len = 0;
  }
  else if (qn->upper == 1 && qn->greedy) {
    if (qn->lower == 0) {
      if (CKN_ON) {
        len = SIZE_OP_STATE_CHECK_PUSH + tlen;
      }
      else {
        len = SIZE_OP_PUSH + tlen;
      }
    }
    else {
      len = tlen;
    }
  }
  else if (!qn->greedy && qn->upper == 1 && qn->lower == 0) { /* '??' */
    len = SIZE_OP_PUSH + cklen + SIZE_OP_JUMP + tlen;
  }
  else {
    len = SIZE_OP_REPEAT_INC
        + mod_tlen + SIZE_OPCODE + SIZE_RELADDR + SIZE_MEMNUM;
    if (CKN_ON)
      len += SIZE_OP_STATE_CHECK;
  }

  return len;
}

static int
compile_quantifier_node(QtfrNode* qn, regex_t* reg)
{
  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);

  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;
    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 (CKN_ON) {
        r = add_state_check_num(reg, ckn);
        if (r) return r;
      }

      return add_bytes(reg, NSTR(qn->next_head_exact)->s, 1);
    }
    else {
      if (IS_MULTILINE(reg->options)) {
        r = add_opcode(reg, (CKN_ON ?
                               OP_STATE_CHECK_ANYCHAR_ML_STAR
                             : OP_ANYCHAR_ML_STAR));
      }
      else {
        r = add_opcode(reg, (CKN_ON ?
                               OP_STATE_CHECK_ANYCHAR_STAR
                             : OP_ANYCHAR_STAR));
      }
      if (r) return r;
      if (CKN_ON)
        r = add_state_check_num(reg, ckn);

      return r;
    }
  }

  if (empty_info != 0)
    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
  else
    mod_tlen = tlen;

  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 (CKN_ON) {
        r = add_opcode(reg, OP_STATE_CHECK_PUSH);
        if (r) return r;
        r = add_state_check_num(reg, ckn);
        if (r) 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;
      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)));
    }
    else {
      if (qn->lower == 0) {
        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 (CKN_ON) {
        r = add_opcode(reg, OP_STATE_CHECK_PUSH_OR_JUMP);
        if (r) return r;
        r = add_state_check_num(reg, ckn);
        if (r) return r;
        r = add_rel_addr(reg,
                 -(mod_tlen + (int )SIZE_OP_STATE_CHECK_PUSH_OR_JUMP));
      }
      else
        r = add_opcode_rel_addr(reg, OP_PUSH, -(mod_tlen + (int )SIZE_OP_PUSH));
    }
  }
  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);
    }
    else
      r = 0;
  }
  else if (qn->upper == 1 && qn->greedy) {
    if (qn->lower == 0) {
      if (CKN_ON) {
        r = add_opcode(reg, OP_STATE_CHECK_PUSH);
        if (r) return r;
        r = add_state_check_num(reg, ckn);
        if (r) return r;
        r = add_rel_addr(reg, tlen);
      }
      else {
        r = add_opcode_rel_addr(reg, OP_PUSH, tlen);
      }
      if (r) return r;
    }

    r = compile_tree(qn->target, reg);
  }
  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;
      r = add_state_check_num(reg, ckn);
      if (r) 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;
    r = add_opcode_rel_addr(reg, OP_JUMP, tlen);
    if (r) return r;
    r = compile_tree(qn->target, reg);
  }
  else {
    r = compile_range_repeat_node(qn, mod_tlen, empty_info, reg);
    if (CKN_ON) {
      if (r) return r;
      r = add_opcode(reg, OP_STATE_CHECK);
      if (r) return r;
      r = add_state_check_num(reg, ckn);
    }
  }
  return r;
}

#else /* USE_COMBINATION_EXPLOSION_CHECK */

static int
compile_length_quantifier_node(QtfrNode* 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);

  if (tlen < 0) return tlen;

  /* anychar repeat */
  if (NTYPE(qn->target) == NT_CANY) {
    if (qn->greedy && infinite) {
      if (IS_NOT_NULL(qn->next_head_exact))
        return SIZE_OP_ANYCHAR_STAR_PEEK_NEXT + tlen * qn->lower;
      else
        return SIZE_OP_ANYCHAR_STAR + tlen * qn->lower;
    }
  }

  if (empty_info != 0)
    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
  else
    mod_tlen = tlen;

  if (infinite &&
      (qn->lower <= 1 || tlen * qn->lower <= QUANTIFIER_EXPAND_LIMIT_SIZE)) {
    if (qn->lower == 1 && tlen > QUANTIFIER_EXPAND_LIMIT_SIZE) {
      len = SIZE_OP_JUMP;
    }
    else {
      len = tlen * qn->lower;
    }

    if (qn->greedy) {
      if (IS_NOT_NULL(qn->head_exact))
        len += SIZE_OP_PUSH_OR_JUMP_EXACT1 + mod_tlen + SIZE_OP_JUMP;
      else if (IS_NOT_NULL(qn->next_head_exact))
        len += SIZE_OP_PUSH_IF_PEEK_NEXT + mod_tlen + SIZE_OP_JUMP;
      else
        len += SIZE_OP_PUSH + mod_tlen + SIZE_OP_JUMP;
    }
    else
      len += SIZE_OP_JUMP + mod_tlen + SIZE_OP_PUSH;
  }
  else if (qn->upper == 0 && qn->is_refered != 0) { /* /(?<n>..){0}/ */
    len = SIZE_OP_JUMP + tlen;
  }
  else if (!infinite && qn->greedy &&
           (qn->upper == 1 || (tlen + SIZE_OP_PUSH) * qn->upper
                                      <= QUANTIFIER_EXPAND_LIMIT_SIZE)) {
    len = tlen * qn->lower;
    len += (SIZE_OP_PUSH + tlen) * (qn->upper - qn->lower);
  }
  else if (!qn->greedy && qn->upper == 1 && qn->lower == 0) { /* '??' */
    len = SIZE_OP_PUSH + SIZE_OP_JUMP + tlen;
  }
  else {
    len = SIZE_OP_REPEAT_INC
        + mod_tlen + SIZE_OPCODE + SIZE_RELADDR + SIZE_MEMNUM;
  }

  return len;
}

static int
compile_quantifier_node(QtfrNode* qn, regex_t* reg)
{
  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);

  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;
    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);
    }
    else {
      if (IS_MULTILINE(reg->options))
        return add_opcode(reg, OP_ANYCHAR_ML_STAR);
      else
        return add_opcode(reg, OP_ANYCHAR_STAR);
    }
  }

  if (empty_info != 0)
    mod_tlen = tlen + (SIZE_OP_NULL_CHECK_START + SIZE_OP_NULL_CHECK_END);
  else
    mod_tlen = tlen;

  if (infinite &&
      (qn->lower <= 1 || tlen * qn->lower <= QUANTIFIER_EXPAND_LIMIT_SIZE)) {
    if (qn->lower == 1 && tlen > QUANTIFIER_EXPAND_LIMIT_SIZE) {
      if (qn->greedy) {
        if (IS_NOT_NULL(qn->head_exact))
          r = add_opcode_rel_addr(reg, OP_JUMP, SIZE_OP_PUSH_OR_JUMP_EXACT1);
        else if (IS_NOT_NULL(qn->next_head_exact))
          r = add_opcode_rel_addr(reg, OP_JUMP, SIZE_OP_PUSH_IF_PEEK_NEXT);
        else
          r = add_opcode_rel_addr(reg, OP_JUMP, SIZE_OP_PUSH);
      }
      else {
        r = add_opcode_rel_addr(reg, OP_JUMP, SIZE_OP_JUMP);
      }
      if (r) return r;
    }
    else {
      r = compile_tree_n_times(qn->target, qn->lower, reg);
      if (r) 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;
        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;
        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;
        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;
      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);
  }
  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;

    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;
    }
  }
  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;
    r = add_opcode_rel_addr(reg, OP_JUMP, tlen);
    if (r) return r;
    r = compile_tree(qn->target, reg);
  }
  else {
    r = compile_range_repeat_node(qn, mod_tlen, empty_info, reg);
  }
  return r;
}
#endif /* USE_COMBINATION_EXPLOSION_CHECK */

static int
compile_length_option_node(EncloseNode* node, regex_t* reg)
{
  int tlen;
  OnigOptionType prev = reg->options;

  reg->options = node->option;
  tlen = compile_length_tree(node->target, reg);
  reg->options = prev;

  if (tlen < 0) return tlen;

  if (IS_DYNAMIC_OPTION(prev ^ node->option)) {
    return SIZE_OP_SET_OPTION_PUSH + SIZE_OP_SET_OPTION + SIZE_OP_FAIL
           + tlen + SIZE_OP_SET_OPTION;
  }
  else
    return tlen;
}

static int
compile_option_node(EncloseNode* node, regex_t* reg)
{
  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;
    r = add_opcode_option(reg, OP_SET_OPTION, prev);
    if (r) return r;
    r = add_opcode(reg, OP_FAIL);
    if (r) return r;
  }

  reg->options = node->option;
  r = compile_tree(node->target, reg);
  reg->options = prev;

  if (IS_DYNAMIC_OPTION(prev ^ node->option)) {
    if (r) return r;
    r = add_opcode_option(reg, OP_SET_OPTION, prev);
  }
  return r;
}

static int
compile_length_enclose_node(EncloseNode* node, regex_t* reg)
{
  int len;
  int tlen;

  if (node->type == ENCLOSE_OPTION)
    return compile_length_option_node(node, reg);

  if (node->target) {
    tlen = compile_length_tree(node->target, reg);
    if (tlen < 0) return tlen;
  }
  else
    tlen = 0;

  switch (node->type) {
  case ENCLOSE_MEMORY:
#ifdef USE_SUBEXP_CALL
    if (IS_ENCLOSE_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)
                ? 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);
    }
    else
#endif
    {
      if (BIT_STATUS_AT(reg->bt_mem_start, node->regnum))
        len = SIZE_OP_MEMORY_START_PUSH;
      else
        len = SIZE_OP_MEMORY_START;

      len += tlen + (BIT_STATUS_AT(reg->bt_mem_end, node->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);
      if (tlen < 0) return tlen;

      len = tlen * qn->lower
          + SIZE_OP_PUSH + tlen + SIZE_OP_POP + SIZE_OP_JUMP;
    }
    else {
      len = SIZE_OP_PUSH_STOP_BT + tlen + SIZE_OP_POP_STOP_BT;
    }
    break;

  default:
    return ONIGERR_TYPE_BUG;
    break;
  }

  return len;
}

static int get_char_length_tree(Node* node, regex_t* reg, int* len);

static int
compile_enclose_node(EncloseNode* node, regex_t* reg)
{
  int r, len;

  if (node->type == ENCLOSE_OPTION)
    return compile_option_node(node, reg);

  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);

      r = add_opcode_rel_addr(reg, OP_JUMP, len);
      if (r) 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
#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);
    }
    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;

      len = compile_length_tree(qn->target, 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;
      r = add_opcode(reg, OP_POP);
      if (r) 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;
      r = add_opcode(reg, OP_POP_STOP_BT);
    }
    break;

  default:
    return ONIGERR_TYPE_BUG;
    break;
  }

  return r;
}

static int
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 (tlen < 0) return tlen;
  }

  switch (node->type) {
  case ANCHOR_PREC_READ:
    len = SIZE_OP_PUSH_POS + tlen + SIZE_OP_POP_POS;
    break;
  case ANCHOR_PREC_READ_NOT:
    len = SIZE_OP_PUSH_POS_NOT + tlen + SIZE_OP_FAIL_POS;
    break;
  case ANCHOR_LOOK_BEHIND:
    len = SIZE_OP_LOOK_BEHIND + tlen;
    break;
  case ANCHOR_LOOK_BEHIND_NOT:
    len = SIZE_OP_PUSH_LOOK_BEHIND_NOT + tlen + SIZE_OP_FAIL_LOOK_BEHIND_NOT;
    break;

  default:
    len = SIZE_OPCODE;
    break;
  }

  return len;
}

static int
compile_anchor_node(AnchorNode* node, regex_t* reg)
{
  int r, len;

  switch (node->type) {
  case ANCHOR_BEGIN_BUF:      r = add_opcode(reg, OP_BEGIN_BUF);      break;
  case ANCHOR_END_BUF:        r = add_opcode(reg, OP_END_BUF);        break;
  case ANCHOR_BEGIN_LINE:     r = add_opcode(reg, OP_BEGIN_LINE);     break;
  case ANCHOR_END_LINE:       r = add_opcode(reg, OP_END_LINE);       break;
  case ANCHOR_SEMI_END_BUF:   r = add_opcode(reg, OP_SEMI_END_BUF);   break;
  case ANCHOR_BEGIN_POSITION: r = add_opcode(reg, OP_BEGIN_POSITION); break;

  case ANCHOR_WORD_BOUND:     r = add_opcode(reg, OP_WORD_BOUND);     break;
  case ANCHOR_NOT_WORD_BOUND: r = add_opcode(reg, OP_NOT_WORD_BOUND); break;
#ifdef USE_WORD_BEGIN_END
  case ANCHOR_WORD_BEGIN:     r = add_opcode(reg, OP_WORD_BEGIN);     break;
  case ANCHOR_WORD_END:       r = add_opcode(reg, OP_WORD_END);       break;
#endif

  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;
    r = add_opcode(reg, OP_POP_POS);
    break;

  case ANCHOR_PREC_READ_NOT:
    len = compile_length_tree(node->target, 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;
    r = add_opcode(reg, OP_FAIL_POS);
    break;

  case ANCHOR_LOOK_BEHIND:
    {
      int n;
      r = add_opcode(reg, OP_LOOK_BEHIND);
      if (r) return r;
      if (node->char_len < 0) {
        r = get_char_length_tree(node->target, reg, &n);
        if (r) 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);
    }
    break;

  case ANCHOR_LOOK_BEHIND_NOT:
    {
      int n;
      len = compile_length_tree(node->target, reg);
      r = add_opcode_rel_addr(reg, OP_PUSH_LOOK_BEHIND_NOT,
                           len + SIZE_OP_FAIL_LOOK_BEHIND_NOT);
      if (r) return r;
      if (node->char_len < 0) {
        r = get_char_length_tree(node->target, reg, &n);
        if (r) 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;
      r = add_opcode(reg, OP_FAIL_LOOK_BEHIND_NOT);
    }
    break;

  default:
    return ONIGERR_TYPE_BUG;
    break;
  }

  return r;
}

static int
compile_length_tree(Node* node, regex_t* reg)
{
  int len, type, r;

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
    len = 0;
    do {
      r = compile_length_tree(NCAR(node), reg);
      if (r < 0) return r;
      len += r;
    } while (IS_NOT_NULL(node = NCDR(node)));
    r = len;
    break;

  case NT_ALT:
    {
      int n;

      n = r = 0;
      do {
        r += compile_length_tree(NCAR(node), reg);
        n++;
      } while (IS_NOT_NULL(node = NCDR(node)));
      r += (SIZE_OP_PUSH + SIZE_OP_JUMP) * (n - 1);
    }
    break;

  case NT_STR:
    if (NSTRING_IS_RAW(node))
      r = compile_length_string_raw_node(NSTR(node), reg);
    else
      r = compile_length_string_node(node, reg);
    break;

  case NT_CCLASS:
    r = compile_length_cclass_node(NCCLASS(node), reg);
    break;

  case NT_CTYPE:
  case NT_CANY:
    r = SIZE_OPCODE;
    break;

  case NT_BREF:
    {
      BRefNode* br = NBREF(node);

#ifdef USE_BACKREF_WITH_LEVEL
      if (IS_BACKREF_NEST_LEVEL(br)) {
        r = SIZE_OPCODE + SIZE_OPTION + SIZE_LENGTH +
            SIZE_LENGTH + (SIZE_MEMNUM * br->back_num);
      }
      else
#endif
      if (br->back_num == 1) {
        r = ((!IS_IGNORECASE(reg->options) && br->back_static[0] <= 2)
             ? SIZE_OPCODE : (SIZE_OPCODE + SIZE_MEMNUM));
      }
      else {
        r = SIZE_OPCODE + SIZE_LENGTH + (SIZE_MEMNUM * br->back_num);
      }
    }
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    r = SIZE_OP_CALL;
    break;
#endif

  case NT_QTFR:
    r = compile_length_quantifier_node(NQTFR(node), reg);
    break;

  case NT_ENCLOSE:
    r = compile_length_enclose_node(NENCLOSE(node), reg);
    break;

  case NT_ANCHOR:
    r = compile_length_anchor_node(NANCHOR(node), reg);
    break;

  default:
    return ONIGERR_TYPE_BUG;
    break;
  }

  return r;
}

static int
compile_tree(Node* node, regex_t* reg)
{
  int n, type, len, pos, r = 0;

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
    do {
      r = compile_tree(NCAR(node), reg);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_ALT:
    {
      Node* x = node;
      len = 0;
      do {
        len += compile_length_tree(NCAR(x), reg);
        if (NCDR(x) != NULL) {
          len += SIZE_OP_PUSH + SIZE_OP_JUMP;
        }
      } while (IS_NOT_NULL(x = NCDR(x)));
      pos = reg->used + len;  /* goal position */

      do {
        len = compile_length_tree(NCAR(node), reg);
        if (IS_NOT_NULL(NCDR(node))) {
          r = add_opcode_rel_addr(reg, OP_PUSH, len + SIZE_OP_JUMP);
          if (r) break;
        }
        r = compile_tree(NCAR(node), reg);
        if (r) break;
        if (IS_NOT_NULL(NCDR(node))) {
          len = pos - (reg->used + SIZE_OP_JUMP);
          r = add_opcode_rel_addr(reg, OP_JUMP, len);
          if (r) break;
        }
      } while (IS_NOT_NULL(node = NCDR(node)));
    }
    break;

  case NT_STR:
    if (NSTRING_IS_RAW(node))
      r = compile_string_raw_node(NSTR(node), reg);
    else
      r = compile_string_node(node, reg);
    break;

  case NT_CCLASS:
    r = compile_cclass_node(NCCLASS(node), reg);
    break;

  case NT_CTYPE:
    {
      int op;

      switch (NCTYPE(node)->ctype) {
      case ONIGENC_CTYPE_WORD:
        if (NCTYPE(node)->is_not != 0)  op = OP_NOT_WORD;
        else                            op = OP_WORD;
        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:
    {
      BRefNode* br = NBREF(node);

#ifdef USE_BACKREF_WITH_LEVEL
      if (IS_BACKREF_NEST_LEVEL(br)) {
        r = add_opcode(reg, OP_BACKREF_WITH_LEVEL);
        if (r) return r;
        r = add_option(reg, (reg->options & ONIG_OPTION_IGNORECASE));
        if (r) return r;
        r = add_length(reg, br->nest_level);
        if (r) return r;

        goto add_bacref_mems;
      }
      else
#endif
      if (br->back_num == 1) {
        n = br->back_static[0];
        if (IS_IGNORECASE(reg->options)) {
          r = add_opcode(reg, OP_BACKREFN_IC);
          if (r) return r;
          r = add_mem_num(reg, n);
        }
        else {
          switch (n) {
          case 1:  r = add_opcode(reg, OP_BACKREF1); break;
          case 2:  r = add_opcode(reg, OP_BACKREF2); break;
          default:
            r = add_opcode(reg, OP_BACKREFN);
            if (r) return r;
            r = add_mem_num(reg, n);
            break;
          }
        }
      }
      else {
        int i;
        int* p;

        if (IS_IGNORECASE(reg->options)) {
          r = add_opcode(reg, OP_BACKREF_MULTI_IC);
        }
        else {
          r = add_opcode(reg, OP_BACKREF_MULTI);
        }
        if (r) return r;

#ifdef USE_BACKREF_WITH_LEVEL
      add_bacref_mems:
#endif
        r = add_length(reg, br->back_num);
        if (r) 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;
        }
      }
    }
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    r = compile_call(NCALL(node), reg);
    break;
#endif

  case NT_QTFR:
    r = compile_quantifier_node(NQTFR(node), reg);
    break;

  case NT_ENCLOSE:
    r = compile_enclose_node(NENCLOSE(node), reg);
    break;

  case NT_ANCHOR:
    r = compile_anchor_node(NANCHOR(node), reg);
    break;

  default:
#ifdef ONIG_DEBUG
    fprintf(stderr, "compile_tree: undefined node type %d\n", NTYPE(node));
#endif
    break;
  }

  return r;
}

#ifdef USE_NAMED_GROUP

static int
noname_disable_map(Node** plink, GroupNumRemap* map, int* counter)
{
  int r = 0;
  Node* node = *plink;

  switch (NTYPE(node)) {
  case NT_LIST:
  case NT_ALT:
    do {
      r = noname_disable_map(&(NCAR(node)), map, counter);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_QTFR:
    {
      Node** ptarget = &(NQTFR(node)->target);
      Node*  old = *ptarget;
      r = noname_disable_map(ptarget, map, counter);
      if (*ptarget != old && NTYPE(*ptarget) == NT_QTFR) {
        onig_reduce_nested_quantifier(node, *ptarget);
      }
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      if (en->type == ENCLOSE_MEMORY) {
        if (IS_ENCLOSE_NAMED_GROUP(en)) {
          (*counter)++;
          map[en->regnum].new_val = *counter;
          en->regnum = *counter;
          r = noname_disable_map(&(en->target), map, counter);
        }
        else {
          *plink = en->target;
          en->target = NULL_NODE;
          onig_node_free(node);
          r = noname_disable_map(plink, map, counter);
        }
      }
      else
        r = noname_disable_map(&(en->target), map, counter);
    }
    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 = noname_disable_map(&(an->target), map, counter);
        break;
      }
    }
    break;

  default:
    break;
  }

  return r;
}

static int
renumber_node_backref(Node* node, GroupNumRemap* map)
{
  int i, pos, n, old_num;
  int *backs;
  BRefNode* bn = NBREF(node);

  if (! IS_BACKREF_NAME_REF(bn))
    return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;

  old_num = bn->back_num;
  if (IS_NULL(bn->back_dynamic))
    backs = bn->back_static;
  else
    backs = bn->back_dynamic;

  for (i = 0, pos = 0; i < old_num; i++) {
    n = map[backs[i]].new_val;
    if (n > 0) {
      backs[pos] = n;
      pos++;
    }
  }

  bn->back_num = pos;
  return 0;
}

static int
renumber_by_map(Node* node, GroupNumRemap* map)
{
  int r = 0;

  switch (NTYPE(node)) {
  case NT_LIST:
  case NT_ALT:
    do {
      r = renumber_by_map(NCAR(node), map);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(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);
    break;

  case NT_BREF:
    r = renumber_node_backref(node, map);
    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 = renumber_by_map(an->target, map);
        break;
      }
    }
    break;

  default:
    break;
  }

  return r;
}

static int
numbered_ref_check(Node* node)
{
  int r = 0;

  switch (NTYPE(node)) {
  case NT_LIST:
  case NT_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);
    break;

  case NT_BREF:
    if (! IS_BACKREF_NAME_REF(NBREF(node)))
      return ONIGERR_NUMBERED_BACKREF_OR_CALL_NOT_ALLOWED;
    break;

  default:
    break;
  }

  return r;
}

static int
disable_noname_group_capture(Node** root, regex_t* reg, ScanEnv* env)
{
  int r, i, pos, counter;
  BitStatusType loc;
  GroupNumRemap* map;

  map = (GroupNumRemap* )xalloca(sizeof(GroupNumRemap) * (env->num_mem + 1));
  CHECK_NULL_RETURN_MEMERR(map);
  for (i = 1; i <= env->num_mem; i++) {
    map[i].new_val = 0;
  }
  counter = 0;
  r = noname_disable_map(root, map, &counter);
  if (r != 0) return r;

  r = renumber_by_map(*root, map);
  if (r != 0) return r;

  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];
      pos++;
    }
  }

  loc = env->capture_history;
  BIT_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);
    }
  }

  env->num_mem = env->num_named;
  reg->num_mem = env->num_named;

  return onig_renumber_name_table(reg, map);
}
#endif /* USE_NAMED_GROUP */

#ifdef USE_SUBEXP_CALL
static int
unset_addr_list_fix(UnsetAddrList* uslist, regex_t* reg)
{
  int i, offset;
  EncloseNode* 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;
    offset = uslist->us[i].offset;

    BBUF_WRITE(reg, offset, &addr, SIZE_ABSADDR);
  }
  return 0;
}
#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 */

static int
get_min_match_length(Node* node, OnigDistance *min, ScanEnv* env)
{
  OnigDistance tmin;
  int r = 0;

  *min = 0;
  switch (NTYPE(node)) {
  case NT_BREF:
    {
      int i;
      int* backs;
      Node** nodes = SCANENV_MEM_NODES(env);
      BRefNode* br = NBREF(node);
      if (br->state & NST_RECURSION) break;

      backs = BACKREFS_P(br);
      if (backs[0] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
      r = get_min_match_length(nodes[backs[0]], min, env);
      if (r != 0) break;
      for (i = 1; i < br->back_num; i++) {
        if (backs[i] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
        r = get_min_match_length(nodes[backs[i]], &tmin, env);
        if (r != 0) break;
        if (*min > tmin) *min = 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;
    }
    else
      r = get_min_match_length(NCALL(node)->target, min, env);
    break;
#endif

  case NT_LIST:
    do {
      r = get_min_match_length(NCAR(node), &tmin, env);
      if (r == 0) *min += tmin;
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_ALT:
    {
      Node *x, *y;
      y = node;
      do {
        x = NCAR(y);
        r = get_min_match_length(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)));
    }
    break;

  case NT_STR:
    {
      StrNode* sn = NSTR(node);
      *min = sn->end - sn->s;
    }
    break;

  case NT_CTYPE:
    *min = 1;
    break;

  case NT_CCLASS:
  case NT_CANY:
    *min = 1;
    break;

  case NT_QTFR:
    {
      QtfrNode* qn = NQTFR(node);

      if (qn->lower > 0) {
        r = get_min_match_length(qn->target, min, env);
        if (r == 0)
          *min = distance_multiply(*min, qn->lower);
      }
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      switch (en->type) {
      case ENCLOSE_MEMORY:
#ifdef USE_SUBEXP_CALL
        if (IS_ENCLOSE_MIN_FIXED(en))
          *min = en->min_len;
        else {
          r = get_min_match_length(en->target, min, env);
          if (r == 0) {
            en->min_len = *min;
            SET_ENCLOSE_STATUS(node, NST_MIN_FIXED);
          }
        }
        break;
#endif
      case ENCLOSE_OPTION:
      case ENCLOSE_STOP_BACKTRACK:
        r = get_min_match_length(en->target, min, env);
        break;
      }
    }
    break;

  case NT_ANCHOR:
  default:
    break;
  }

  return r;
}

static int
get_max_match_length(Node* node, OnigDistance *max, ScanEnv* env)
{
  OnigDistance tmax;
  int r = 0;

  *max = 0;
  switch (NTYPE(node)) {
  case NT_LIST:
    do {
      r = get_max_match_length(NCAR(node), &tmax, env);
      if (r == 0)
        *max = distance_add(*max, tmax);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_ALT:
    do {
      r = get_max_match_length(NCAR(node), &tmax, env);
      if (r == 0 && *max < tmax) *max = tmax;
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_STR:
    {
      StrNode* sn = NSTR(node);
      *max = sn->end - sn->s;
    }
    break;

  case NT_CTYPE:
    *max = ONIGENC_MBC_MAXLEN_DIST(env->enc);
    break;

  case NT_CCLASS:
  case NT_CANY:
    *max = ONIGENC_MBC_MAXLEN_DIST(env->enc);
    break;

  case NT_BREF:
    {
      int i;
      int* backs;
      Node** nodes = SCANENV_MEM_NODES(env);
      BRefNode* br = NBREF(node);
      if (br->state & NST_RECURSION) {
        *max = 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_match_length(nodes[backs[i]], &tmax, env);
        if (r != 0) break;
        if (*max < tmax) *max = tmax;
      }
    }
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    if (! IS_CALL_RECURSION(NCALL(node)))
      r = get_max_match_length(NCALL(node)->target, max, env);
    else
      *max = ONIG_INFINITE_DISTANCE;
    break;
#endif

  case NT_QTFR:
    {
      QtfrNode* qn = NQTFR(node);

      if (qn->upper != 0) {
        r = get_max_match_length(qn->target, max, env);
        if (r == 0 && *max != 0) {
          if (! IS_REPEAT_INFINITE(qn->upper))
            *max = distance_multiply(*max, qn->upper);
          else
            *max = ONIG_INFINITE_DISTANCE;
        }
      }
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      switch (en->type) {
      case ENCLOSE_MEMORY:
#ifdef USE_SUBEXP_CALL
        if (IS_ENCLOSE_MAX_FIXED(en))
          *max = en->max_len;
        else {
          r = get_max_match_length(en->target, max, env);
          if (r == 0) {
            en->max_len = *max;
            SET_ENCLOSE_STATUS(node, NST_MAX_FIXED);
          }
        }
        break;
#endif
      case ENCLOSE_OPTION:
      case ENCLOSE_STOP_BACKTRACK:
        r = get_max_match_length(en->target, max, env);
        break;
      }
    }
    break;

  case NT_ANCHOR:
  default:
    break;
  }

  return r;
}

#define GET_CHAR_LEN_VARLEN           -1
#define GET_CHAR_LEN_TOP_ALT_VARLEN   -2

/* fixed size pattern node only */
static int
get_char_length_tree1(Node* node, regex_t* reg, int* len, int level)
{
  int tlen;
  int r = 0;

  level++;
  *len = 0;
  switch (NTYPE(node)) {
  case NT_LIST:
    do {
      r = get_char_length_tree1(NCAR(node), reg, &tlen, level);
      if (r == 0)
        *len = distance_add(*len, tlen);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_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);
        if (r == 0) {
          if (tlen != tlen2)
            varlen = 1;
        }
      }
      if (r == 0) {
        if (varlen != 0) {
          if (level == 1)
            r = GET_CHAR_LEN_TOP_ALT_VARLEN;
          else
            r = GET_CHAR_LEN_VARLEN;
        }
        else
          *len = tlen;
      }
    }
    break;

  case NT_STR:
    {
      StrNode* sn = NSTR(node);
      UChar *s = sn->s;
      while (s < sn->end) {
        s += enclen(reg->enc, s, sn->end);
        (*len)++;
      }
    }
    break;

  case NT_QTFR:
    {
      QtfrNode* qn = NQTFR(node);
      if (qn->lower == qn->upper) {
        r = get_char_length_tree1(qn->target, reg, &tlen, level);
        if (r == 0)
          *len = distance_multiply(tlen, qn->lower);
      }
      else
        r = GET_CHAR_LEN_VARLEN;
    }
    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);
    else
      r = GET_CHAR_LEN_VARLEN;
    break;
#endif

  case NT_CTYPE:
    *len = 1;
    break;

  case NT_CCLASS:
  case NT_CANY:
    *len = 1;
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      switch (en->type) {
      case ENCLOSE_MEMORY:
#ifdef USE_SUBEXP_CALL
        if (IS_ENCLOSE_CLEN_FIXED(en))
          *len = en->char_len;
        else {
          r = get_char_length_tree1(en->target, reg, len, level);
          if (r == 0) {
            en->char_len = *len;
            SET_ENCLOSE_STATUS(node, NST_CLEN_FIXED);
          }
        }
        break;
#endif
      case ENCLOSE_OPTION:
      case ENCLOSE_STOP_BACKTRACK:
        r = get_char_length_tree1(en->target, reg, len, level);
        break;
      default:
        break;
      }
    }
    break;

  case NT_ANCHOR:
    break;

  default:
    r = GET_CHAR_LEN_VARLEN;
    break;
  }

  return r;
}

static int
get_char_length_tree(Node* node, regex_t* reg, int* len)
{
  return get_char_length_tree1(node, reg, len, 0);
}

/* x is not included y ==>  1 : 0 */
static int
is_not_included(Node* x, Node* y, regex_t* reg)
{
  int i, len;
  OnigCodePoint code;
  UChar *p, c;
  int ytype;

 retry:
  ytype = NTYPE(y);
  switch (NTYPE(x)) {
  case NT_CTYPE:
    {
      switch (ytype) {
      case NT_CTYPE:
        if (NCTYPE(y)->ctype  == NCTYPE(x)->ctype &&
            NCTYPE(y)->is_not != NCTYPE(x)->is_not)
          return 1;
        else
          return 0;
        break;

      case NT_CCLASS:
      swap:
        {
          Node* tmp;
          tmp = x; x = y; y = tmp;
          goto retry;
        }
        break;

      case NT_STR:
        goto swap;
        break;

      default:
        break;
      }
    }
    break;

  case NT_CCLASS:
    {
      CClassNode* xc = NCCLASS(x);
      switch (ytype) {
      case NT_CTYPE:
        switch (NCTYPE(y)->ctype) {
        case ONIGENC_CTYPE_WORD:
          if (NCTYPE(y)->is_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)) {
                  if (IS_CODE_SB_WORD(reg->enc, i)) return 0;
                }
              }
              return 1;
            }
            return 0;
          }
          else {
            for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
              if (! IS_CODE_SB_WORD(reg->enc, i)) {
                if (!IS_NCCLASS_NOT(xc)) {
                  if (BITSET_AT(xc->bs, i))
                    return 0;
                }
                else {
                  if (! BITSET_AT(xc->bs, i))
                    return 0;
                }
              }
            }
            return 1;
          }
          break;

        default:
          break;
        }
        break;

      case NT_CCLASS:
        {
          int v;
          CClassNode* yc = NCCLASS(y);

          for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
            v = BITSET_AT(xc->bs, i);
            if ((v != 0 && !IS_NCCLASS_NOT(xc)) ||
                (v == 0 && IS_NCCLASS_NOT(xc))) {
              v = BITSET_AT(yc->bs, i);
              if ((v != 0 && !IS_NCCLASS_NOT(yc)) ||
                  (v == 0 && IS_NCCLASS_NOT(yc)))
                return 0;
            }
          }
          if ((IS_NULL(xc->mbuf) && !IS_NCCLASS_NOT(xc)) ||
              (IS_NULL(yc->mbuf) && !IS_NCCLASS_NOT(yc)))
            return 1;
          return 0;
        }
        break;

      case NT_STR:
        goto swap;
        break;

      default:
        break;
      }
    }
    break;

  case NT_STR:
    {
      StrNode* xs = NSTR(x);
      if (NSTRING_LEN(x) == 0)
        break;

      c = *(xs->s);
      switch (ytype) {
      case NT_CTYPE:
        switch (NCTYPE(y)->ctype) {
        case ONIGENC_CTYPE_WORD:
          if (ONIGENC_IS_MBC_WORD(reg->enc, xs->s, xs->end))
            return NCTYPE(y)->is_not;
          else
            return !(NCTYPE(y)->is_not);
          break;
        default:
          break;
        }
        break;

      case NT_CCLASS:
        {
          CClassNode* cc = NCCLASS(y);

          code = ONIGENC_MBC_TO_CODE(reg->enc, xs->s,
                                     xs->s + ONIGENC_MBC_MAXLEN(reg->enc));
          return (onig_is_code_in_cc(reg->enc, code, cc) != 0 ? 0 : 1);
        }
        break;

      case NT_STR:
        {
          UChar *q;
          StrNode* ys = NSTR(y);
          len = NSTRING_LEN(x);
          if (len > NSTRING_LEN(y)) len = NSTRING_LEN(y);
          if (NSTRING_IS_AMBIG(x) || NSTRING_IS_AMBIG(y)) {
            /* tiny version */
            return 0;
          }
          else {
            for (i = 0, p = ys->s, q = xs->s; i < len; i++, p++, q++) {
              if (*p != *q) return 1;
            }
          }
        }
        break;

      default:
        break;
      }
    }
    break;

  default:
    break;
  }

  return 0;
}

static Node*
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:
#ifdef USE_SUBEXP_CALL
  case NT_CALL:
#endif
    break;

  case NT_CTYPE:
  case NT_CCLASS:
    if (exact == 0) {
      n = node;
    }
    break;

  case NT_LIST:
    n = get_head_value_node(NCAR(node), exact, reg);
    break;

  case NT_STR:
    {
      StrNode* sn = NSTR(node);

      if (sn->end <= sn->s)
        break;

      if (exact != 0 &&
          !NSTRING_IS_RAW(node) && IS_IGNORECASE(reg->options)) {
      }
      else {
        n = node;
      }
    }
    break;

  case NT_QTFR:
    {
      QtfrNode* qn = NQTFR(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);
      }
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      switch (en->type) {
      case ENCLOSE_OPTION:
        {
          OnigOptionType options = reg->options;

          reg->options = NENCLOSE(node)->option;
          n = get_head_value_node(NENCLOSE(node)->target, exact, reg);
          reg->options = options;
        }
        break;

      case ENCLOSE_MEMORY:
      case ENCLOSE_STOP_BACKTRACK:
        n = get_head_value_node(en->target, exact, reg);
        break;
      }
    }
    break;

  case NT_ANCHOR:
    if (NANCHOR(node)->type == ANCHOR_PREC_READ)
      n = get_head_value_node(NANCHOR(node)->target, exact, reg);
    break;

  default:
    break;
  }

  return n;
}

static int
check_type_tree(Node* node, int type_mask, int enclose_mask, int anchor_mask)
{
  int type, r = 0;

  type = NTYPE(node);
  if ((NTYPE2BIT(type) & type_mask) == 0)
    return 1;

  switch (type) {
  case NT_LIST:
  case NT_ALT:
    do {
      r = check_type_tree(NCAR(node), type_mask, enclose_mask,
                          anchor_mask);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_QTFR:
    r = check_type_tree(NQTFR(node)->target, type_mask, enclose_mask,
                        anchor_mask);
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      if ((en->type & enclose_mask) == 0)
        return 1;

      r = check_type_tree(en->target, type_mask, enclose_mask, anchor_mask);
    }
    break;

  case NT_ANCHOR:
    type = NANCHOR(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);
    break;

  default:
    break;
  }
  return r;
}

#ifdef USE_SUBEXP_CALL

#define RECURSION_EXIST       1
#define RECURSION_INFINITE    2

static int
subexp_inf_recursive_check(Node* node, ScanEnv* env, int head)
{
  int type;
  int r = 0;

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
    {
      Node *x;
      OnigDistance min;
      int ret;

      x = node;
      do {
        ret = subexp_inf_recursive_check(NCAR(x), env, head);
        if (ret < 0 || ret == RECURSION_INFINITE) return ret;
        r |= ret;
        if (head) {
          ret = get_min_match_length(NCAR(x), &min, env);
          if (ret != 0) return ret;
          if (min != 0) head = 0;
        }
      } while (IS_NOT_NULL(x = NCDR(x)));
    }
    break;

  case NT_ALT:
    {
      int ret;
      r = RECURSION_EXIST;
      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;

  case NT_QTFR:
    r = subexp_inf_recursive_check(NQTFR(node)->target, env, head);
    if (r == RECURSION_EXIST) {
      if (NQTFR(node)->lower == 0) r = 0;
    }
    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;
      }
    }
    break;

  case NT_CALL:
    r = subexp_inf_recursive_check(NCALL(node)->target, 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);
    }
    break;

  default:
    break;
  }

  return r;
}

static int
subexp_inf_recursive_check_trav(Node* node, ScanEnv* env)
{
  int type;
  int r = 0;

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
  case NT_ALT:
    do {
      r = subexp_inf_recursive_check_trav(NCAR(node), env);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(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;
      }
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);

      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);
      }
      r = subexp_inf_recursive_check_trav(en->target, env);
    }

    break;

  default:
    break;
  }

  return r;
}

static int
subexp_recursive_check(Node* node)
{
  int r = 0;

  switch (NTYPE(node)) {
  case NT_LIST:
  case NT_ALT:
    do {
      r |= subexp_recursive_check(NCAR(node));
    } while (IS_NOT_NULL(node = NCDR(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;
      }
    }
    break;

  case NT_CALL:
    r = subexp_recursive_check(NCALL(node)->target);
    if (r != 0) SET_CALL_RECURSION(node);
    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);
    }
    break;

  default:
    break;
  }

  return r;
}


static int
subexp_recursive_check_trav(Node* node, ScanEnv* env)
{
#define FOUND_CALLED_NODE    1

  int type;
  int r = 0;

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
  case NT_ALT:
    {
      int ret;
      do {
        ret = subexp_recursive_check_trav(NCAR(node), env);
        if (ret == FOUND_CALLED_NODE) r = FOUND_CALLED_NODE;
        else if (ret < 0) return ret;
      } while (IS_NOT_NULL(node = NCDR(node)));
    }
    break;

  case NT_QTFR:
    r = subexp_recursive_check_trav(NQTFR(node)->target, env);
    if (NQTFR(node)->upper == 0) {
      if (r == FOUND_CALLED_NODE)
        NQTFR(node)->is_refered = 1;
    }
    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_trav(an->target, env);
        break;
      }
    }
    break;

  case NT_ENCLOSE:
    {
      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;
          }
        }

#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;
        }
      }
#endif
    }
    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 = setup_subexp_call(an->target, env);
        break;
      }
    }
    break;

  default:
    break;
  }

  return r;
}
#endif

/* divide different length alternatives in look-behind.
  (?<=A|B) ==> (?<=A)|(?<=B)
  (?<!A|B) ==> (?<!A)(?<!B)
*/
static int
divide_look_behind_alternatives(Node* node)
{
  Node *head, *np, *insert_node;
  AnchorNode* an = NANCHOR(node);
  int anc_type = an->type;

  head = an->target;
  np = NCAR(head);
  swap_node(node, head);
  NCAR(node) = head;
  NANCHOR(head)->target = np;

  np = node;
  while ((np = NCDR(np)) != NULL_NODE) {
    insert_node = onig_node_new_anchor(anc_type);
    CHECK_NULL_RETURN_MEMERR(insert_node);
    NANCHOR(insert_node)->target = NCAR(np);
    NCAR(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);
  }
  return 0;
}

static int
setup_look_behind(Node* node, regex_t* reg, ScanEnv* env)
{
  int r, len;
  AnchorNode* an = NANCHOR(node);

  r = get_char_length_tree(an->target, reg, &len);
  if (r == 0)
    an->char_len = len;
  else if (r == GET_CHAR_LEN_VARLEN)
    r = ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
  else if (r == GET_CHAR_LEN_TOP_ALT_VARLEN) {
    if (IS_SYNTAX_BV(env->syntax, ONIG_SYN_DIFFERENT_LEN_ALT_LOOK_BEHIND))
      r = divide_look_behind_alternatives(node);
    else
      r = ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
  }

  return r;
}

static int
next_setup(Node* node, Node* next_node, regex_t* reg)
{
  int type;

 retry:
  type = NTYPE(node);
  if (type == NT_QTFR) {
    QtfrNode* qn = NQTFR(node);
    if (qn->greedy && IS_REPEAT_INFINITE(qn->upper)) {
#ifdef USE_QTFR_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') {
        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)) {
          Node *x, *y;
          x = get_head_value_node(qn->target, 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);
              CHECK_NULL_RETURN_MEMERR(en);
              SET_ENCLOSE_STATUS(en, NST_STOP_BT_SIMPLE_REPEAT);
              swap_node(node, en);
              NENCLOSE(node)->target = en;
            }
          }
        }
      }
    }
  }
  else if (type == NT_ENCLOSE) {
    EncloseNode* en = NENCLOSE(node);
    if (en->type == ENCLOSE_MEMORY) {
      node = en->target;
      goto retry;
    }
  }
  return 0;
}


static int
update_string_node_case_fold(regex_t* reg, Node *node)
{
  UChar *p, *q, *end, buf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
  UChar *sbuf, *ebuf, *sp;
  int r, i, len, sbuf_size;
  StrNode* sn = NSTR(node);

  end = sn->end;
  sbuf_size = (end - sn->s) * 2;
  sbuf = (UChar* )xmalloc(sbuf_size);
  CHECK_NULL_RETURN_MEMERR(sbuf);
  ebuf = sbuf + sbuf_size;

  sp = sbuf;
  p = sn->s;
  while (p < end) {
    len = ONIGENC_MBC_CASE_FOLD(reg->enc, reg->case_fold_flag, &p, end, buf);
    q = buf;
    for (i = 0; i < len; i++) {
      if (sp >= ebuf) {
        sbuf = (UChar* )xrealloc(sbuf, sbuf_size * 2);
        CHECK_NULL_RETURN_MEMERR(sbuf);
        sp = sbuf + sbuf_size;
        sbuf_size *= 2;
        ebuf = sbuf + sbuf_size;
      }

      *sp++ = buf[i];
    }
  }

  r = onig_node_str_set(node, sbuf, sp);
  if (r != 0) {
    xfree(sbuf);
    return r;
  }

  xfree(sbuf);
  return 0;
}

static int
expand_case_fold_make_rem_string(Node** rnode, UChar *s, UChar *end,
                                 regex_t* reg)
{
  int r;
  Node *node;

  node = onig_node_new_str(s, end);
  if (IS_NULL(node)) return ONIGERR_MEMORY;

  r = update_string_node_case_fold(reg, node);
  if (r != 0) {
    onig_node_free(node);
    return r;
  }

  NSTRING_SET_AMBIG(node);
  NSTRING_SET_DONT_GET_OPT_INFO(node);
  *rnode = node;
  return 0;
}

static int
expand_case_fold_string_alt(int item_num, OnigCaseFoldCodeItem items[],
                            UChar *p, int slen, UChar *end,
                            regex_t* reg, Node **rnode)
{
  int r, i, j, len, varlen;
  Node *anode, *var_anode, *snode, *xnode, *an;
  UChar buf[ONIGENC_CODE_TO_MBC_MAXLEN];

  *rnode = var_anode = NULL_NODE;

  varlen = 0;
  for (i = 0; i < item_num; i++) {
    if (items[i].byte_len != slen) {
      varlen = 1;
      break;
    }
  }

  if (varlen != 0) {
    *rnode = var_anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
    if (IS_NULL(var_anode)) return ONIGERR_MEMORY;

    xnode = onig_node_new_list(NULL, NULL);
    if (IS_NULL(xnode)) goto mem_err;
    NCAR(var_anode) = xnode;

    anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
    if (IS_NULL(anode)) goto mem_err;
    NCAR(xnode) = anode;
  }
  else {
    *rnode = anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
    if (IS_NULL(anode)) return ONIGERR_MEMORY;
  }

  snode = onig_node_new_str(p, p + slen);
  if (IS_NULL(snode)) goto mem_err;

  NCAR(anode) = snode;

  for (i = 0; i < item_num; i++) {
    snode = onig_node_new_str(NULL, NULL);
    if (IS_NULL(snode)) goto mem_err;

    for (j = 0; j < items[i].code_len; j++) {
      len = ONIGENC_CODE_TO_MBC(reg->enc, items[i].code[j], buf);
      if (len < 0) {
        r = len;
        goto mem_err2;
      }

      r = onig_node_str_cat(snode, buf, buf + len);
      if (r != 0) goto mem_err2;
    }

    an = onig_node_new_alt(NULL_NODE, NULL_NODE);
    if (IS_NULL(an)) {
      goto mem_err2;
    }

    if (items[i].byte_len != slen) {
      Node *rem;
      UChar *q = p + items[i].byte_len;

      if (q < end) {
        r = expand_case_fold_make_rem_string(&rem, q, end, reg);
        if (r != 0) {
          onig_node_free(an);
          goto mem_err2;
        }

        xnode = onig_node_list_add(NULL_NODE, snode);
        if (IS_NULL(xnode)) {
          onig_node_free(an);
          onig_node_free(rem);
          goto mem_err2;
        }
        if (IS_NULL(onig_node_list_add(xnode, rem))) {
          onig_node_free(an);
          onig_node_free(xnode);
          onig_node_free(rem);
          goto mem_err;
        }

        NCAR(an) = xnode;
      }
      else {
        NCAR(an) = snode;
      }

      NCDR(var_anode) = an;
      var_anode = an;
    }
    else {
      NCAR(an)     = snode;
      NCDR(anode) = an;
      anode = an;
    }
  }

  return varlen;

 mem_err2:
  onig_node_free(snode);

 mem_err:
  onig_node_free(*rnode);

  return ONIGERR_MEMORY;
}

static int
expand_case_fold_string(Node* node, regex_t* reg)
{
#define THRESHOLD_CASE_FOLD_ALT_FOR_EXPANSION  8

  int r, n, len, alt_num;
  UChar *start, *end, *p;
  Node *top_root, *root, *snode, *prev_node;
  OnigCaseFoldCodeItem items[ONIGENC_GET_CASE_FOLD_CODES_MAX_NUM];
  StrNode* sn = NSTR(node);

  if (NSTRING_IS_AMBIG(node)) return 0;

  start = sn->s;
  end   = sn->end;
  if (start >= end) return 0;

  r = 0;
  top_root = root = prev_node = snode = NULL_NODE;
  alt_num = 1;
  p = start;
  while (p < end) {
    n = ONIGENC_GET_CASE_FOLD_CODES_BY_STR(reg->enc, reg->case_fold_flag,
                                           p, end, items);
    if (n < 0) {
      r = n;
      goto err;
    }

    len = enclen(reg->enc, p, end);

    if (n == 0) {
      if (IS_NULL(snode)) {
        if (IS_NULL(root) && IS_NOT_NULL(prev_node)) {
          top_root = root = onig_node_list_add(NULL_NODE, prev_node);
          if (IS_NULL(root)) {
            onig_node_free(prev_node);
            goto mem_err;
          }
        }

        prev_node = snode = onig_node_new_str(NULL, NULL);
        if (IS_NULL(snode)) goto mem_err;
        if (IS_NOT_NULL(root)) {
          if (IS_NULL(onig_node_list_add(root, snode))) {
            onig_node_free(snode);
            goto mem_err;
          }
        }
      }

      r = onig_node_str_cat(snode, p, p + len);
      if (r != 0) goto err;
    }
    else {
      alt_num *= (n + 1);
      if (alt_num > THRESHOLD_CASE_FOLD_ALT_FOR_EXPANSION) break;

      if (IS_NULL(root) && IS_NOT_NULL(prev_node)) {
        top_root = root = onig_node_list_add(NULL_NODE, prev_node);
        if (IS_NULL(root)) {
          onig_node_free(prev_node);
          goto mem_err;
        }
      }

      r = expand_case_fold_string_alt(n, items, p, len, end, reg, &prev_node);
      if (r < 0) goto mem_err;
      if (r == 1) {
        if (IS_NULL(root)) {
          top_root = prev_node;
        }
        else {
          if (IS_NULL(onig_node_list_add(root, prev_node))) {
            onig_node_free(prev_node);
            goto mem_err;
          }
        }

        root = NCAR(prev_node);
      }
      else { /* r == 0 */
        if (IS_NOT_NULL(root)) {
          if (IS_NULL(onig_node_list_add(root, prev_node))) {
            onig_node_free(prev_node);
            goto mem_err;
          }
        }
      }

      snode = NULL_NODE;
    }

    p += len;
  }

  if (p < end) {
    Node *srem;

    r = expand_case_fold_make_rem_string(&srem, p, end, reg);
    if (r != 0) goto mem_err;

    if (IS_NOT_NULL(prev_node) && IS_NULL(root)) {
      top_root = root = onig_node_list_add(NULL_NODE, prev_node);
      if (IS_NULL(root)) {
        onig_node_free(srem);
        onig_node_free(prev_node);
        goto mem_err;
      }
    }

    if (IS_NULL(root)) {
      prev_node = srem;
    }
    else {
      if (IS_NULL(onig_node_list_add(root, srem))) {
        onig_node_free(srem);
        goto mem_err;
      }
    }
  }

  /* ending */
  top_root = (IS_NOT_NULL(top_root) ? top_root : prev_node);
  swap_node(node, top_root);
  onig_node_free(top_root);
  return 0;

 mem_err:
  r = ONIGERR_MEMORY;

 err:
  onig_node_free(top_root);
  return r;
}


#ifdef USE_COMBINATION_EXPLOSION_CHECK

#define CEC_THRES_NUM_BIG_REPEAT         512
#define CEC_INFINITE_NUM          0x7fffffff

#define CEC_IN_INFINITE_REPEAT    (1<<0)
#define CEC_IN_FINITE_REPEAT      (1<<1)
#define CEC_CONT_BIG_REPEAT       (1<<2)

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:
    {
      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)));
    }
    break;

  case NT_ALT:
    {
      int ret;
      do {
        ret = setup_comb_exp_check(NCAR(node), state, env);
        r |= ret;
      } while (ret >= 0 && IS_NOT_NULL(node = NCDR(node)));
    }
    break;

  case NT_QTFR:
    {
      int child_state = state;
      int add_state = 0;
      QtfrNode* qn = NQTFR(node);
      Node* target = qn->target;
      int var_num;

      if (! IS_REPEAT_INFINITE(qn->upper)) {
        if (qn->upper > 1) {
          /* {0,1}, {1,1} are allowed */
          child_state |= CEC_IN_FINITE_REPEAT;

          /* 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 (IS_REPEAT_INFINITE(q->upper)
                      && q->greedy == qn->greedy) {
                    qn->upper = (qn->lower == 0 ? 1 : qn->lower);
                    if (qn->upper == 1)
                      child_state = state;
                  }
                }
              }
            }
          }
        }
      }

      if (state & CEC_IN_FINITE_REPEAT) {
        qn->comb_exp_check_num = -1;
      }
      else {
        if (IS_REPEAT_INFINITE(qn->upper)) {
          var_num = CEC_INFINITE_NUM;
          child_state |= CEC_IN_INFINITE_REPEAT;
        }
        else {
          var_num = qn->upper - qn->lower;
        }

        if (var_num >= CEC_THRES_NUM_BIG_REPEAT)
          add_state |= CEC_CONT_BIG_REPEAT;

        if (((state & CEC_IN_INFINITE_REPEAT) != 0 && var_num != 0) ||
            ((state & CEC_CONT_BIG_REPEAT) != 0 &&
             var_num >= CEC_THRES_NUM_BIG_REPEAT)) {
          if (qn->comb_exp_check_num == 0) {
            env->num_comb_exp_check++;
            qn->comb_exp_check_num = env->num_comb_exp_check;
            if (env->curr_max_regnum > env->comb_exp_max_regnum)
              env->comb_exp_max_regnum = env->curr_max_regnum;
          }
        }
      }

      r = setup_comb_exp_check(target, child_state, env);
      r |= add_state;
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);

      switch (en->type) {
      case ENCLOSE_MEMORY:
        {
          if (env->curr_max_regnum < en->regnum)
            env->curr_max_regnum = en->regnum;

          r = setup_comb_exp_check(en->target, state, env);
        }
        break;

      default:
        r = setup_comb_exp_check(en->target, state, env);
        break;
      }
    }
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    if (IS_CALL_RECURSION(NCALL(node)))
      env->has_recursion = 1;
    else
      r = setup_comb_exp_check(NCALL(node)->target, state, env);
    break;
#endif

  default:
    break;
  }

  return r;
}
#endif

#define IN_ALT        (1<<0)
#define IN_NOT        (1<<1)
#define IN_REPEAT     (1<<2)
#define IN_VAR_REPEAT (1<<3)

/* 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.
 */
static int
setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
{
  int type;
  int r = 0;

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
    {
      Node* prev = NULL_NODE;
      do {
        r = setup_tree(NCAR(node), reg, state, env);
        if (IS_NOT_NULL(prev) && r == 0) {
          r = next_setup(prev, NCAR(node), reg);
        }
        prev = NCAR(node);
      } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    }
    break;

  case NT_ALT:
    do {
      r = setup_tree(NCAR(node), reg, (state | IN_ALT), env);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;

  case NT_CCLASS:
    break;

  case NT_STR:
    if (IS_IGNORECASE(reg->options) && !NSTRING_IS_RAW(node)) {
      r = expand_case_fold_string(node, reg);
    }
    break;

  case NT_CTYPE:
  case NT_CANY:
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    break;
#endif

  case NT_BREF:
    {
      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]);
        }
#endif
        SET_ENCLOSE_STATUS(nodes[p[i]], NST_MEM_BACKREFED);
      }
    }
    break;

  case NT_QTFR:
    {
      OnigDistance d;
      QtfrNode* qn = NQTFR(node);
      Node* target = qn->target;

      if ((state & IN_REPEAT) != 0) {
        qn->state |= NST_IN_REPEAT;
      }

      if (IS_REPEAT_INFINITE(qn->upper) || qn->upper >= 1) {
        r = get_min_match_length(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;
          }
#endif
        }
      }

      state |= IN_REPEAT;
      if (qn->lower != qn->upper)
        state |= IN_VAR_REPEAT;
      r = setup_tree(target, reg, state, env);
      if (r) break;

      /* 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: */
          }
        }
      }

#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;
          }
        }
        else {
          qn->head_exact = get_head_value_node(qn->target, 1, reg);
        }
      }
#endif
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);

      switch (en->type) {
      case ENCLOSE_OPTION:
        {
          OnigOptionType options = reg->options;
          reg->options = NENCLOSE(node)->option;
          r = setup_tree(NENCLOSE(node)->target, reg, state, env);
          reg->options = options;
        }
        break;

      case ENCLOSE_MEMORY:
        if ((state & (IN_ALT | IN_NOT | IN_VAR_REPEAT)) != 0) {
          BIT_STATUS_ON_AT(env->bt_mem_start, en->regnum);
          /* SET_ENCLOSE_STATUS(node, NST_MEM_IN_ALT_NOT); */
        }
        r = setup_tree(en->target, reg, state, env);
        break;

      case ENCLOSE_STOP_BACKTRACK:
        {
          Node* target = en->target;
          r = setup_tree(target, reg, state, env);
          if (NTYPE(target) == NT_QTFR) {
            QtfrNode* tqn = NQTFR(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);
            }
          }
        }
        break;
      }
    }
    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 )
#define ALLOWED_ENCLOSE_IN_LB_NOT   0

#define ALLOWED_ANCHOR_IN_LB \
( ANCHOR_LOOK_BEHIND | ANCHOR_BEGIN_LINE | ANCHOR_END_LINE | ANCHOR_BEGIN_BUF | ANCHOR_BEGIN_POSITION )
#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 )

      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_look_behind(node, reg, env);
          if (r != 0) return r;
          r = setup_tree(an->target, 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_look_behind(node, reg, env);
          if (r != 0) return r;
          r = setup_tree(an->target, reg, (state | IN_NOT), env);
        }
        break;
      }
    }
    break;

  default:
    break;
  }

  return r;
}

/* set skip map for Boyer-Moor search */
static int
set_bm_skip(UChar* s, UChar* end, OnigEncoding enc ARG_UNUSED,
            UChar skip[], int** int_skip)
{
  int i, len;

  len = end - s;
  if (len < ONIG_CHAR_TABLE_SIZE) {
    for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++) skip[i] = len;

    for (i = 0; i < len - 1; i++)
      skip[s[i]] = len - 1 - i;
  }
  else {
    if (IS_NULL(*int_skip)) {
      *int_skip = (int* )xmalloc(sizeof(int) * ONIG_CHAR_TABLE_SIZE);
      if (IS_NULL(*int_skip)) return ONIGERR_MEMORY;
    }
    for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++) (*int_skip)[i] = len;

    for (i = 0; i < len - 1; i++)
      (*int_skip)[s[i]] = len - 1 - i;
  }
  return 0;
}

#define OPT_EXACT_MAXLEN   24

typedef struct {
  OnigDistance min;  /* min byte length */
  OnigDistance max;  /* max byte length */
} MinMaxLen;

typedef struct {
  MinMaxLen        mmd;
  OnigEncoding     enc;
  OnigOptionType   options;
  OnigCaseFoldType case_fold_flag;
  ScanEnv*         scan_env;
} OptEnv;

typedef struct {
  int left_anchor;
  int right_anchor;
} OptAncInfo;

typedef struct {
  MinMaxLen  mmd; /* info position */
  OptAncInfo anc;

  int   reach_end;
  int   ignore_case;
  int   len;
  UChar s[OPT_EXACT_MAXLEN];
} OptExactInfo;

typedef struct {
  MinMaxLen mmd; /* info position */
  OptAncInfo anc;

  int   value;      /* weighted value */
  UChar map[ONIG_CHAR_TABLE_SIZE];
} OptMapInfo;

typedef struct {
  MinMaxLen    len;

  OptAncInfo   anc;
  OptExactInfo exb;    /* boundary */
  OptExactInfo exm;    /* middle */
  OptExactInfo expr;   /* prec read (?=...) */

  OptMapInfo   map;   /* boundary */
} NodeOptInfo;


static int
map_position_value(OnigEncoding enc, int i)
{
  static const short int ByteValTable[] = {
     5,  1,  1,  1,  1,  1,  1,  1,  1, 10, 10,  1,  1, 10,  1,  1,
     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
    12,  4,  7,  4,  4,  4,  4,  4,  4,  5,  5,  5,  5,  5,  5,  5,
     6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  5,  5,  5,  5,  5,  5,
     5,  6,  6,  6,  6,  7,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,
     6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  5,  6,  5,  5,  5,
     5,  6,  6,  6,  6,  7,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,
     6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  5,  5,  5,  5,  1
  };

  if (i < (int )(sizeof(ByteValTable)/sizeof(ByteValTable[0]))) {
    if (i == 0 && ONIGENC_MBC_MINLEN(enc) > 1)
      return 20;
    else
      return (int )ByteValTable[i];
  }
  else
    return 4;   /* Take it easy. */
}

static int
distance_value(MinMaxLen* mm)
{
  /* 1000 / (min-max-dist + 1) */
  static const short int dist_vals[] = {
    1000,  500,  333,  250,  200,  167,  143,  125,  111,  100,
      91,   83,   77,   71,   67,   63,   59,   56,   53,   50,
      48,   45,   43,   42,   40,   38,   37,   36,   34,   33,
      32,   31,   30,   29,   29,   28,   27,   26,   26,   25,
      24,   24,   23,   23,   22,   22,   21,   21,   20,   20,
      20,   19,   19,   19,   18,   18,   18,   17,   17,   17,
      16,   16,   16,   16,   15,   15,   15,   15,   14,   14,
      14,   14,   14,   14,   13,   13,   13,   13,   13,   13,
      12,   12,   12,   12,   12,   12,   11,   11,   11,   11,
      11,   11,   11,   11,   11,   10,   10,   10,   10,   10
  };

  int d;

  if (mm->max == ONIG_INFINITE_DISTANCE) return 0;

  d = mm->max - mm->min;
  if (d < (int )(sizeof(dist_vals)/sizeof(dist_vals[0])))
    /* return dist_vals[d] * 16 / (mm->min + 12); */
    return (int )dist_vals[d];
  else
    return 1;
}

static int
comp_distance_value(MinMaxLen* d1, MinMaxLen* d2, int v1, int v2)
{
  if (v2 <= 0) return -1;
  if (v1 <= 0) return  1;

  v1 *= distance_value(d1);
  v2 *= distance_value(d2);

  if (v2 > v1) return  1;
  if (v2 < v1) return -1;

  if (d2->min < d1->min) return  1;
  if (d2->min > d1->min) return -1;
  return 0;
}

static int
is_equal_mml(MinMaxLen* a, MinMaxLen* b)
{
  return (a->min == b->min && a->max == b->max) ? 1 : 0;
}


static void
set_mml(MinMaxLen* mml, OnigDistance min, OnigDistance max)
{
  mml->min = min;
  mml->max = max;
}

static void
clear_mml(MinMaxLen* mml)
{
  mml->min = mml->max = 0;
}

static void
copy_mml(MinMaxLen* to, MinMaxLen* from)
{
  to->min = from->min;
  to->max = from->max;
}

static void
add_mml(MinMaxLen* to, MinMaxLen* from)
{
  to->min = distance_add(to->min, from->min);
  to->max = distance_add(to->max, from->max);
}

static void
alt_merge_mml(MinMaxLen* to, MinMaxLen* from)
{
  if (to->min > from->min) to->min = from->min;
  if (to->max < from->max) to->max = from->max;
}

static void
copy_opt_env(OptEnv* to, OptEnv* from)
{
  *to = *from;
}

static void
clear_opt_anc_info(OptAncInfo* anc)
{
  anc->left_anchor  = 0;
  anc->right_anchor = 0;
}

static void
copy_opt_anc_info(OptAncInfo* to, OptAncInfo* from)
{
  *to = *from;
}

static void
concat_opt_anc_info(OptAncInfo* to, OptAncInfo* left, OptAncInfo* right,
                    OnigDistance left_len, OnigDistance right_len)
{
  clear_opt_anc_info(to);

  to->left_anchor = left->left_anchor;
  if (left_len == 0) {
    to->left_anchor |= right->left_anchor;
  }

  to->right_anchor = right->right_anchor;
  if (right_len == 0) {
    to->right_anchor |= left->right_anchor;
  }
}

static int
is_left_anchor(int anc)
{
  if (anc == ANCHOR_END_BUF || anc == ANCHOR_SEMI_END_BUF ||
      anc == ANCHOR_END_LINE || anc == ANCHOR_PREC_READ ||
      anc == ANCHOR_PREC_READ_NOT)
    return 0;

  return 1;
}

static int
is_set_opt_anc_info(OptAncInfo* to, int anc)
{
  if ((to->left_anchor & anc) != 0) return 1;

  return ((to->right_anchor & anc) != 0 ? 1 : 0);
}

static void
add_opt_anc_info(OptAncInfo* to, int anc)
{
  if (is_left_anchor(anc))
    to->left_anchor |= anc;
  else
    to->right_anchor |= anc;
}

static void
remove_opt_anc_info(OptAncInfo* to, int anc)
{
  if (is_left_anchor(anc))
    to->left_anchor &= ~anc;
  else
    to->right_anchor &= ~anc;
}

static void
alt_merge_opt_anc_info(OptAncInfo* to, OptAncInfo* add)
{
  to->left_anchor  &= add->left_anchor;
  to->right_anchor &= add->right_anchor;
}

static int
is_full_opt_exact_info(OptExactInfo* ex)
{
  return (ex->len >= OPT_EXACT_MAXLEN ? 1 : 0);
}

static void
clear_opt_exact_info(OptExactInfo* ex)
{
  clear_mml(&ex->mmd);
  clear_opt_anc_info(&ex->anc);
  ex->reach_end   = 0;
  ex->ignore_case = 0;
  ex->len         = 0;
  ex->s[0]        = '\0';
}

static void
copy_opt_exact_info(OptExactInfo* to, OptExactInfo* from)
{
  *to = *from;
}

static void
concat_opt_exact_info(OptExactInfo* to, OptExactInfo* add, OnigEncoding enc)
{
  int i, j, len;
  UChar *p, *end;
  OptAncInfo tanc;

  if (! to->ignore_case && add->ignore_case) {
    if (to->len >= add->len) return ;  /* avoid */

    to->ignore_case = 1;
  }

  p = add->s;
  end = p + add->len;
  for (i = to->len; p < end; ) {
    len = enclen(enc, p, end);
    if (i + len > OPT_EXACT_MAXLEN) break;
    for (j = 0; j < len && p < end; j++)
      to->s[i++] = *p++;
  }

  to->len = i;
  to->reach_end = (p == end ? add->reach_end : 0);

  concat_opt_anc_info(&tanc, &to->anc, &add->anc, 1, 1);
  if (! to->reach_end) tanc.right_anchor = 0;
  copy_opt_anc_info(&to->anc, &tanc);
}

static void
concat_opt_exact_info_str(OptExactInfo* to, UChar* s, UChar* end,
                          int raw ARG_UNUSED, OnigEncoding enc)
{
  int i, j, len;
  UChar *p;

  for (i = to->len, p = s; p < end && i < OPT_EXACT_MAXLEN; ) {
    len = enclen(enc, p, end);
    if (i + len > OPT_EXACT_MAXLEN) break;
    for (j = 0; j < len && p < end; j++)
      to->s[i++] = *p++;
  }

  to->len = i;
}

static void
alt_merge_opt_exact_info(OptExactInfo* to, OptExactInfo* add, OptEnv* env)
{
  int i, j, len;

  if (add->len == 0 || to->len == 0) {
    clear_opt_exact_info(to);
    return ;
  }

  if (! is_equal_mml(&to->mmd, &add->mmd)) {
    clear_opt_exact_info(to);
    return ;
  }

  for (i = 0; i < to->len && i < add->len; ) {
    if (to->s[i] != add->s[i]) break;
    len = enclen(env->enc, to->s + i, to->s + to->len);

    for (j = 1; j < len; j++) {
      if (to->s[i+j] != add->s[i+j]) break;
    }
    if (j < len) break;
    i += len;
  }

  if (! add->reach_end || i < add->len || i < to->len) {
    to->reach_end = 0;
  }
  to->len = i;
  to->ignore_case |= add->ignore_case;

  alt_merge_opt_anc_info(&to->anc, &add->anc);
  if (! to->reach_end) to->anc.right_anchor = 0;
}

static void
select_opt_exact_info(OnigEncoding enc, OptExactInfo* now, OptExactInfo* alt)
{
  int v1, v2;

  v1 = now->len;
  v2 = alt->len;

  if (v2 == 0) {
    return ;
  }
  else if (v1 == 0) {
    copy_opt_exact_info(now, alt);
    return ;
  }
  else if (v1 <= 2 && v2 <= 2) {
    /* ByteValTable[x] is big value --> low price */
    v2 = map_position_value(enc, now->s[0]);
    v1 = map_position_value(enc, alt->s[0]);

    if (now->len > 1) v1 += 5;
    if (alt->len > 1) v2 += 5;
  }

  if (now->ignore_case == 0) v1 *= 2;
  if (alt->ignore_case == 0) v2 *= 2;

  if (comp_distance_value(&now->mmd, &alt->mmd, v1, v2) > 0)
    copy_opt_exact_info(now, alt);
}

static void
clear_opt_map_info(OptMapInfo* map)
{
  static const OptMapInfo clean_info = {
    {0, 0}, {0, 0}, 0,
    {
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
    }
  };

  xmemcpy(map, &clean_info, sizeof(OptMapInfo));
}

static void
copy_opt_map_info(OptMapInfo* to, OptMapInfo* from)
{
  *to = *from;
}

static void
add_char_opt_map_info(OptMapInfo* map, UChar c, OnigEncoding enc)
{
  if (map->map[c] == 0) {
    map->map[c] = 1;
    map->value += map_position_value(enc, c);
  }
}

static int
add_char_amb_opt_map_info(OptMapInfo* map, UChar* p, UChar* end,
                          OnigEncoding enc, OnigCaseFoldType case_fold_flag)
{
  OnigCaseFoldCodeItem items[ONIGENC_GET_CASE_FOLD_CODES_MAX_NUM];
  UChar buf[ONIGENC_CODE_TO_MBC_MAXLEN];
  int i, n;

  add_char_opt_map_info(map, p[0], enc);

  case_fold_flag = DISABLE_CASE_FOLD_MULTI_CHAR(case_fold_flag);
  n = ONIGENC_GET_CASE_FOLD_CODES_BY_STR(enc, case_fold_flag, p, end, items);
  if (n < 0) return n;

  for (i = 0; i < n; i++) {
    ONIGENC_CODE_TO_MBC(enc, items[i].code[0], buf);
    add_char_opt_map_info(map, buf[0], enc);
  }

  return 0;
}

static void
select_opt_map_info(OptMapInfo* now, OptMapInfo* alt)
{
  const int z = 1<<15; /* 32768: something big value */

  int v1, v2;

  if (alt->value == 0) return ;
  if (now->value == 0) {
    copy_opt_map_info(now, alt);
    return ;
  }

  v1 = z / now->value;
  v2 = z / alt->value;
  if (comp_distance_value(&now->mmd, &alt->mmd, v1, v2) > 0)
    copy_opt_map_info(now, alt);
}

static int
comp_opt_exact_or_map_info(OptExactInfo* e, OptMapInfo* m)
{
#define COMP_EM_BASE  20
  int ve, vm;

  if (m->value <= 0) return -1;

  ve = COMP_EM_BASE * e->len * (e->ignore_case ? 1 : 2);
  vm = COMP_EM_BASE * 5 * 2 / m->value;
  return comp_distance_value(&e->mmd, &m->mmd, ve, vm);
}

static void
alt_merge_opt_map_info(OnigEncoding enc, OptMapInfo* to, OptMapInfo* add)
{
  int i, val;

  /* if (! is_equal_mml(&to->mmd, &add->mmd)) return ; */
  if (to->value == 0) return ;
  if (add->value == 0 || to->mmd.max < add->mmd.min) {
    clear_opt_map_info(to);
    return ;
  }

  alt_merge_mml(&to->mmd, &add->mmd);

  val = 0;
  for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++) {
    if (add->map[i])
      to->map[i] = 1;

    if (to->map[i])
      val += map_position_value(enc, i);
  }
  to->value = val;

  alt_merge_opt_anc_info(&to->anc, &add->anc);
}

static void
set_bound_node_opt_info(NodeOptInfo* opt, MinMaxLen* mmd)
{
  copy_mml(&(opt->exb.mmd),  mmd);
  copy_mml(&(opt->expr.mmd), mmd);
  copy_mml(&(opt->map.mmd),  mmd);
}

static void
clear_node_opt_info(NodeOptInfo* opt)
{
  clear_mml(&opt->len);
  clear_opt_anc_info(&opt->anc);
  clear_opt_exact_info(&opt->exb);
  clear_opt_exact_info(&opt->exm);
  clear_opt_exact_info(&opt->expr);
  clear_opt_map_info(&opt->map);
}

static void
copy_node_opt_info(NodeOptInfo* to, NodeOptInfo* from)
{
  *to = *from;
}

static void
concat_left_node_opt_info(OnigEncoding enc, NodeOptInfo* to, NodeOptInfo* add)
{
  int exb_reach, exm_reach;
  OptAncInfo tanc;

  concat_opt_anc_info(&tanc, &to->anc, &add->anc, to->len.max, add->len.max);
  copy_opt_anc_info(&to->anc, &tanc);

  if (add->exb.len > 0 && to->len.max == 0) {
    concat_opt_anc_info(&tanc, &to->anc, &add->exb.anc,
                        to->len.max, add->len.max);
    copy_opt_anc_info(&add->exb.anc, &tanc);
  }

  if (add->map.value > 0 && to->len.max == 0) {
    if (add->map.mmd.max == 0)
      add->map.anc.left_anchor |= to->anc.left_anchor;
  }

  exb_reach = to->exb.reach_end;
  exm_reach = to->exm.reach_end;

  if (add->len.max != 0)
    to->exb.reach_end = to->exm.reach_end = 0;

  if (add->exb.len > 0) {
    if (exb_reach) {
      concat_opt_exact_info(&to->exb, &add->exb, enc);
      clear_opt_exact_info(&add->exb);
    }
    else if (exm_reach) {
      concat_opt_exact_info(&to->exm, &add->exb, enc);
      clear_opt_exact_info(&add->exb);
    }
  }
  select_opt_exact_info(enc, &to->exm, &add->exb);
  select_opt_exact_info(enc, &to->exm, &add->exm);

  if (to->expr.len > 0) {
    if (add->len.max > 0) {
      if (to->expr.len > (int )add->len.max)
        to->expr.len = add->len.max;

      if (to->expr.mmd.max == 0)
        select_opt_exact_info(enc, &to->exb, &to->expr);
      else
        select_opt_exact_info(enc, &to->exm, &to->expr);
    }
  }
  else if (add->expr.len > 0) {
    copy_opt_exact_info(&to->expr, &add->expr);
  }

  select_opt_map_info(&to->map, &add->map);

  add_mml(&to->len, &add->len);
}

static void
alt_merge_node_opt_info(NodeOptInfo* to, NodeOptInfo* add, OptEnv* env)
{
  alt_merge_opt_anc_info  (&to->anc,  &add->anc);
  alt_merge_opt_exact_info(&to->exb,  &add->exb, env);
  alt_merge_opt_exact_info(&to->exm,  &add->exm, env);
  alt_merge_opt_exact_info(&to->expr, &add->expr, env);
  alt_merge_opt_map_info(env->enc, &to->map,  &add->map);

  alt_merge_mml(&to->len, &add->len);
}


#define MAX_NODE_OPT_INFO_REF_COUNT    5

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:
    {
      OptEnv nenv;
      NodeOptInfo nopt;
      Node* nd = node;

      copy_opt_env(&nenv, env);
      do {
        r = optimize_node_left(NCAR(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)));
    }
    break;

  case NT_ALT:
    {
      NodeOptInfo nopt;
      Node* nd = node;

      do {
        r = optimize_node_left(NCAR(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)));
    }
    break;

  case NT_STR:
    {
      StrNode* sn = NSTR(node);
      int slen = sn->end - sn->s;
      int is_raw = NSTRING_IS_RAW(node);

      if (! NSTRING_IS_AMBIG(node)) {
        concat_opt_exact_info_str(&opt->exb, sn->s, sn->end,
                                  NSTRING_IS_RAW(node), env->enc);
        if (slen > 0) {
          add_char_opt_map_info(&opt->map, *(sn->s), env->enc);
        }
        set_mml(&opt->len, slen, slen);
      }
      else {
        int max;

        if (NSTRING_IS_DONT_GET_OPT_INFO(node)) {
          int n = onigenc_strlen(env->enc, sn->s, sn->end);
          max = ONIGENC_MBC_MAXLEN_DIST(env->enc) * n;
        }
        else {
          concat_opt_exact_info_str(&opt->exb, sn->s, sn->end,
                                    is_raw, env->enc);
          opt->exb.ignore_case = 1;

          if (slen > 0) {
            r = add_char_amb_opt_map_info(&opt->map, sn->s, sn->end,
                                          env->enc, env->case_fold_flag);
            if (r != 0) break;
          }

          max = slen;
        }

        set_mml(&opt->len, slen, max);
      }

      if (opt->exb.len == slen)
        opt->exb.reach_end = 1;
    }
    break;

  case NT_CCLASS:
    {
      int i, z;
      CClassNode* cc = NCCLASS(node);

      /* no need to check ignore case. (setted in setup_tree()) */

      if (IS_NOT_NULL(cc->mbuf) || IS_NCCLASS_NOT(cc)) {
        OnigDistance min = ONIGENC_MBC_MINLEN(env->enc);
        OnigDistance max = ONIGENC_MBC_MAXLEN_DIST(env->enc);

        set_mml(&opt->len, min, max);
      }
      else {
        for (i = 0; i < SINGLE_BYTE_SIZE; i++) {
          z = BITSET_AT(cc->bs, i);
          if ((z && !IS_NCCLASS_NOT(cc)) || (!z && IS_NCCLASS_NOT(cc))) {
            add_char_opt_map_info(&opt->map, (UChar )i, env->enc);
          }
        }
        set_mml(&opt->len, 1, 1);
      }
    }
    break;

  case NT_CTYPE:
    {
      int i, min, max;

      max = ONIGENC_MBC_MAXLEN_DIST(env->enc);

      if (max == 1) {
        min = 1;

        switch (NCTYPE(node)->ctype) {
        case ONIGENC_CTYPE_WORD:
          if (NCTYPE(node)->is_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);
              }
            }
          }
          else {
            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);
              }
            }
          }
          break;
        }
      }
      else {
        min = ONIGENC_MBC_MINLEN(env->enc);
      }
      set_mml(&opt->len, min, max);
    }
    break;

  case NT_CANY:
    {
      OnigDistance min = ONIGENC_MBC_MINLEN(env->enc);
      OnigDistance max = ONIGENC_MBC_MAXLEN_DIST(env->enc);
      set_mml(&opt->len, min, max);
    }
    break;

  case NT_ANCHOR:
    switch (NANCHOR(node)->type) {
    case ANCHOR_BEGIN_BUF:
    case ANCHOR_BEGIN_POSITION:
    case ANCHOR_BEGIN_LINE:
    case ANCHOR_END_BUF:
    case ANCHOR_SEMI_END_BUF:
    case ANCHOR_END_LINE:
      add_opt_anc_info(&opt->anc, NANCHOR(node)->type);
      break;

    case ANCHOR_PREC_READ:
      {
        NodeOptInfo nopt;

        r = optimize_node_left(NANCHOR(node)->target, &nopt, env);
        if (r == 0) {
          if (nopt.exb.len > 0)
            copy_opt_exact_info(&opt->expr, &nopt.exb);
          else if (nopt.exm.len > 0)
            copy_opt_exact_info(&opt->expr, &nopt.exm);

          opt->expr.reach_end = 0;

          if (nopt.map.value > 0)
            copy_opt_map_info(&opt->map, &nopt.map);
        }
      }
      break;

    case ANCHOR_PREC_READ_NOT:
    case ANCHOR_LOOK_BEHIND: /* Sorry, I can't make use of it. */
    case ANCHOR_LOOK_BEHIND_NOT:
      break;
    }
    break;

  case NT_BREF:
    {
      int i;
      int* backs;
      OnigDistance min, max, tmin, tmax;
      Node** nodes = SCANENV_MEM_NODES(env->scan_env);
      BRefNode* br = NBREF(node);

      if (br->state & NST_RECURSION) {
        set_mml(&opt->len, 0, ONIG_INFINITE_DISTANCE);
        break;
      }
      backs = BACKREFS_P(br);
      r = get_min_match_length(nodes[backs[0]], &min, env->scan_env);
      if (r != 0) break;
      r = get_max_match_length(nodes[backs[0]], &max, env->scan_env);
      if (r != 0) break;
      for (i = 1; i < br->back_num; i++) {
        r = get_min_match_length(nodes[backs[i]], &tmin, env->scan_env);
        if (r != 0) break;
        r = get_max_match_length(nodes[backs[i]], &tmax, env->scan_env);
        if (r != 0) break;
        if (min > tmin) min = tmin;
        if (max < tmax) max = tmax;
      }
      if (r == 0) set_mml(&opt->len, min, max);
    }
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    if (IS_CALL_RECURSION(NCALL(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 = save;
    }
    break;
#endif

  case NT_QTFR:
    {
      int i;
      OnigDistance min, max;
      NodeOptInfo nopt;
      QtfrNode* qn = NQTFR(node);

      r = optimize_node_left(qn->target, &nopt, env);
      if (r) break;

      if (qn->lower == 0 && IS_REPEAT_INFINITE(qn->upper)) {
        if (env->mmd.max == 0 &&
            NTYPE(qn->target) == NT_CANY && qn->greedy) {
          if (IS_MULTILINE(env->options))
            add_opt_anc_info(&opt->anc, ANCHOR_ANYCHAR_STAR_ML);
          else
            add_opt_anc_info(&opt->anc, ANCHOR_ANYCHAR_STAR);
        }
      }
      else {
        if (qn->lower > 0) {
          copy_node_opt_info(opt, &nopt);
          if (nopt.exb.len > 0) {
            if (nopt.exb.reach_end) {
              for (i = 2; i <= qn->lower &&
                          ! is_full_opt_exact_info(&opt->exb); i++) {
                concat_opt_exact_info(&opt->exb, &nopt.exb, env->enc);
              }
              if (i < qn->lower) {
                opt->exb.reach_end = 0;
              }
            }
          }

          if (qn->lower != qn->upper) {
            opt->exb.reach_end = 0;
            opt->exm.reach_end = 0;
          }
          if (qn->lower > 1)
            opt->exm.reach_end = 0;
        }
      }

      min = distance_multiply(nopt.len.min, qn->lower);
      if (IS_REPEAT_INFINITE(qn->upper))
        max = (nopt.len.max > 0 ? ONIG_INFINITE_DISTANCE : 0);
      else
        max = distance_multiply(nopt.len.max, qn->upper);

      set_mml(&opt->len, min, max);
    }
    break;

  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);

      switch (en->type) {
      case ENCLOSE_OPTION:
        {
          OnigOptionType save = env->options;

          env->options = en->option;
          r = optimize_node_left(en->target, opt, env);
          env->options = save;
        }
        break;

      case ENCLOSE_MEMORY:
#ifdef USE_SUBEXP_CALL
        en->opt_count++;
        if (en->opt_count > MAX_NODE_OPT_INFO_REF_COUNT) {
          OnigDistance min, max;

          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;
          set_mml(&opt->len, min, max);
        }
        else
#endif
        {
          r = optimize_node_left(en->target, 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))
              remove_opt_anc_info(&opt->anc, ANCHOR_ANYCHAR_STAR_MASK);
          }
        }
        break;

      case ENCLOSE_STOP_BACKTRACK:
        r = optimize_node_left(en->target, opt, env);
        break;
      }
    }
    break;

  default:
#ifdef ONIG_DEBUG
    fprintf(stderr, "optimize_node_left: undefined node type %d\n",
            NTYPE(node));
#endif
    r = ONIGERR_TYPE_BUG;
    break;
  }

  return r;
}

static int
set_optimize_exact_info(regex_t* reg, OptExactInfo* e)
{
  int r;

  if (e->len == 0) return 0;

  if (e->ignore_case) {
    reg->exact = (UChar* )xmalloc(e->len);
    CHECK_NULL_RETURN_MEMERR(reg->exact);
    xmemcpy(reg->exact, e->s, e->len);
    reg->exact_end = reg->exact + e->len;
    reg->optimize = ONIG_OPTIMIZE_EXACT_IC;
  }
  else {
    int allow_reverse;

    reg->exact = str_dup(e->s, e->s + e->len);
    CHECK_NULL_RETURN_MEMERR(reg->exact);
    reg->exact_end = reg->exact + e->len;

    allow_reverse =
        ONIGENC_IS_ALLOWED_REVERSE_MATCH(reg->enc, reg->exact, reg->exact_end);

    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;

      reg->optimize = (allow_reverse != 0
                       ? ONIG_OPTIMIZE_EXACT_BM : ONIG_OPTIMIZE_EXACT_BM_NOT_REV);
    }
    else {
      reg->optimize = ONIG_OPTIMIZE_EXACT;
    }
  }

  reg->dmin = e->mmd.min;
  reg->dmax = e->mmd.max;

  if (reg->dmin != ONIG_INFINITE_DISTANCE) {
    reg->threshold_len = reg->dmin + (reg->exact_end - reg->exact);
  }

  return 0;
}

static void
set_optimize_map_info(regex_t* reg, OptMapInfo* m)
{
  int i;

  for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++)
    reg->map[i] = m->map[i];

  reg->optimize   = ONIG_OPTIMIZE_MAP;
  reg->dmin       = m->mmd.min;
  reg->dmax       = m->mmd.max;

  if (reg->dmin != ONIG_INFINITE_DISTANCE) {
    reg->threshold_len = reg->dmin + 1;
  }
}

static void
set_sub_anchor(regex_t* reg, OptAncInfo* anc)
{
  reg->sub_anchor |= anc->left_anchor  & ANCHOR_BEGIN_LINE;
  reg->sub_anchor |= anc->right_anchor & ANCHOR_END_LINE;
}

#ifdef ONIG_DEBUG
static void print_optimize_info(FILE* f, regex_t* reg);
#endif

static int
set_optimize_info_from_tree(Node* node, regex_t* reg, ScanEnv* scan_env)
{

  int r;
  NodeOptInfo opt;
  OptEnv env;

  env.enc            = reg->enc;
  env.options        = reg->options;
  env.case_fold_flag = reg->case_fold_flag;
  env.scan_env   = scan_env;
  clear_mml(&env.mmd);

  r = optimize_node_left(node, &opt, &env);
  if (r) return r;

  reg->anchor = opt.anc.left_anchor & (ANCHOR_BEGIN_BUF |
        ANCHOR_BEGIN_POSITION | ANCHOR_ANYCHAR_STAR | ANCHOR_ANYCHAR_STAR_ML);

  reg->anchor |= opt.anc.right_anchor & (ANCHOR_END_BUF | ANCHOR_SEMI_END_BUF);

  if (reg->anchor & (ANCHOR_END_BUF | ANCHOR_SEMI_END_BUF)) {
    reg->anchor_dmin = opt.len.min;
    reg->anchor_dmax = opt.len.max;
  }

  if (opt.exb.len > 0 || opt.exm.len > 0) {
    select_opt_exact_info(reg->enc, &opt.exb, &opt.exm);
    if (opt.map.value > 0 &&
        comp_opt_exact_or_map_info(&opt.exb, &opt.map) > 0) {
      goto set_map;
    }
    else {
      r = set_optimize_exact_info(reg, &opt.exb);
      set_sub_anchor(reg, &opt.exb.anc);
    }
  }
  else if (opt.map.value > 0) {
  set_map:
    set_optimize_map_info(reg, &opt.map);
    set_sub_anchor(reg, &opt.map.anc);
  }
  else {
    reg->sub_anchor |= opt.anc.left_anchor & ANCHOR_BEGIN_LINE;
    if (opt.len.max == 0)
      reg->sub_anchor |= opt.anc.right_anchor & ANCHOR_END_LINE;
  }

#if defined(ONIG_DEBUG_COMPILE) || defined(ONIG_DEBUG_MATCH)
  print_optimize_info(stderr, reg);
#endif
  return r;
}

static void
clear_optimize_info(regex_t* reg)
{
  reg->optimize      = ONIG_OPTIMIZE_NONE;
  reg->anchor        = 0;
  reg->anchor_dmin   = 0;
  reg->anchor_dmax   = 0;
  reg->sub_anchor    = 0;
  reg->exact_end     = (UChar* )NULL;
  reg->threshold_len = 0;
  if (IS_NOT_NULL(reg->exact)) {
    xfree(reg->exact);
    reg->exact = (UChar* )NULL;
  }
}

#ifdef ONIG_DEBUG

static void print_enc_string(FILE* fp, OnigEncoding enc,
                             const UChar *s, const UChar *end)
{
  fprintf(fp, "\nPATTERN: /");

  if (ONIGENC_MBC_MINLEN(enc) > 1) {
    const UChar *p;
    OnigCodePoint code;

    p = s;
    while (p < end) {
      code = ONIGENC_MBC_TO_CODE(enc, p, end);
      if (code >= 0x80) {
        fprintf(fp, " 0x%04x ", (int )code);
      }
      else {
        fputc((int )code, fp);
      }

      p += enclen(enc, p, end);
    }
  }
  else {
    while (s < end) {
      fputc((int )*s, fp);
      s++;
    }
  }

  fprintf(fp, "/\n");
}

static void
print_distance_range(FILE* f, OnigDistance a, OnigDistance b)
{
  if (a == ONIG_INFINITE_DISTANCE)
    fputs("inf", f);
  else
    fprintf(f, "(%u)", a);

  fputs("-", f);

  if (b == ONIG_INFINITE_DISTANCE)
    fputs("inf", f);
  else
    fprintf(f, "(%u)", b);
}

static void
print_anchor(FILE* f, int anchor)
{
  int q = 0;

  fprintf(f, "[");

  if (anchor & ANCHOR_BEGIN_BUF) {
    fprintf(f, "begin-buf");
    q = 1;
  }
  if (anchor & ANCHOR_BEGIN_LINE) {
    if (q) fprintf(f, ", ");
    q = 1;
    fprintf(f, "begin-line");
  }
  if (anchor & ANCHOR_BEGIN_POSITION) {
    if (q) fprintf(f, ", ");
    q = 1;
    fprintf(f, "begin-pos");
  }
  if (anchor & ANCHOR_END_BUF) {
    if (q) fprintf(f, ", ");
    q = 1;
    fprintf(f, "end-buf");
  }
  if (anchor & ANCHOR_SEMI_END_BUF) {
    if (q) fprintf(f, ", ");
    q = 1;
    fprintf(f, "semi-end-buf");
  }
  if (anchor & ANCHOR_END_LINE) {
    if (q) fprintf(f, ", ");
    q = 1;
    fprintf(f, "end-line");
  }
  if (anchor & ANCHOR_ANYCHAR_STAR) {
    if (q) fprintf(f, ", ");
    q = 1;
    fprintf(f, "anychar-star");
  }
  if (anchor & ANCHOR_ANYCHAR_STAR_ML) {
    if (q) fprintf(f, ", ");
    fprintf(f, "anychar-star-pl");
  }

  fprintf(f, "]");
}

static void
print_optimize_info(FILE* f, regex_t* reg)
{
  static const char* on[] = { "NONE", "EXACT", "EXACT_BM", "EXACT_BM_NOT_REV",
                              "EXACT_IC", "MAP" };

  fprintf(f, "optimize: %s\n", on[reg->optimize]);
  fprintf(f, "  anchor: "); print_anchor(f, reg->anchor);
  if ((reg->anchor & ANCHOR_END_BUF_MASK) != 0)
    print_distance_range(f, reg->anchor_dmin, reg->anchor_dmax);
  fprintf(f, "\n");

  if (reg->optimize) {
    fprintf(f, "  sub anchor: "); print_anchor(f, reg->sub_anchor);
    fprintf(f, "\n");
  }
  fprintf(f, "\n");

  if (reg->exact) {
    UChar *p;
    fprintf(f, "exact: [");
    for (p = reg->exact; p < reg->exact_end; p++) {
      fputc(*p, f);
    }
    fprintf(f, "]: length: %d\n", (reg->exact_end - reg->exact));
  }
  else if (reg->optimize & ONIG_OPTIMIZE_MAP) {
    int c, i, n = 0;

    for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++)
      if (reg->map[i]) n++;

    fprintf(f, "map: n=%d\n", n);
    if (n > 0) {
      c = 0;
      fputc('[', f);
      for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++) {
        if (reg->map[i] != 0) {
          if (c > 0)  fputs(", ", f);
          c++;
          if (ONIGENC_MBC_MAXLEN(reg->enc) == 1 &&
              ONIGENC_IS_CODE_PRINT(reg->enc, (OnigCodePoint )i))
            fputc(i, f);
          else
            fprintf(f, "%d", i);
        }
      }
      fprintf(f, "]\n");
    }
  }
}
#endif /* ONIG_DEBUG */


extern void
onig_free_body(regex_t* reg)
{
  if (IS_NOT_NULL(reg)) {
    if (IS_NOT_NULL(reg->p))                xfree(reg->p);
    if (IS_NOT_NULL(reg->exact))            xfree(reg->exact);
    if (IS_NOT_NULL(reg->int_map))          xfree(reg->int_map);
    if (IS_NOT_NULL(reg->int_map_backward)) xfree(reg->int_map_backward);
    if (IS_NOT_NULL(reg->repeat_range))     xfree(reg->repeat_range);
    if (IS_NOT_NULL(reg->chain))            onig_free(reg->chain);

#ifdef USE_NAMED_GROUP
    onig_names_free(reg);
#endif
  }
}

extern void
onig_free(regex_t* reg)
{
  if (IS_NOT_NULL(reg)) {
    onig_free_body(reg);
    xfree(reg);
  }
}

size_t
onig_memsize(regex_t *reg)
{
    size_t size = sizeof(regex_t);
    if (IS_NOT_NULL(reg->p))                size += reg->alloc;
    if (IS_NOT_NULL(reg->exact))            size += reg->exact_end - reg->exact;
    if (IS_NOT_NULL(reg->int_map))          size += sizeof(int) * ONIG_CHAR_TABLE_SIZE;
    if (IS_NOT_NULL(reg->int_map_backward)) size += sizeof(int) * ONIG_CHAR_TABLE_SIZE;
    if (IS_NOT_NULL(reg->repeat_range))     size += reg->repeat_range_alloc * sizeof(OnigRepeatRange);
    if (IS_NOT_NULL(reg->chain))            size += onig_memsize(reg->chain);

    return size;
}

#define REGEX_TRANSFER(to,from) do {\
  (to)->state = ONIG_STATE_MODIFY;\
  onig_free_body(to);\
  xmemcpy(to, from, sizeof(regex_t));\
  xfree(from);\
} while (0)

extern void
onig_transfer(regex_t* to, regex_t* from)
{
  THREAD_ATOMIC_START;
  REGEX_TRANSFER(to, from);
  THREAD_ATOMIC_END;
}

#define REGEX_CHAIN_HEAD(reg) do {\
  while (IS_NOT_NULL((reg)->chain)) {\
    (reg) = (reg)->chain;\
  }\
} while (0)

extern void
onig_chain_link_add(regex_t* to, regex_t* add)
{
  THREAD_ATOMIC_START;
  REGEX_CHAIN_HEAD(to);
  to->chain = add;
  THREAD_ATOMIC_END;
}

extern void
onig_chain_reduce(regex_t* reg)
{
  regex_t *head, *prev;

  prev = reg;
  head = prev->chain;
  if (IS_NOT_NULL(head)) {
    reg->state = ONIG_STATE_MODIFY;
    while (IS_NOT_NULL(head->chain)) {
      prev = head;
      head = head->chain;
    }
    prev->chain = (regex_t* )NULL;
    REGEX_TRANSFER(reg, head);
  }
}

#ifdef ONIG_DEBUG
static void print_compiled_byte_code_list P_((FILE* f, regex_t* reg));
#endif
#ifdef ONIG_DEBUG_PARSE_TREE
static void print_tree P_((FILE* f, Node* node));
#endif

extern int
onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
              OnigErrorInfo* einfo, const char *sourcefile, int sourceline)
{
#define COMPILE_INIT_SIZE  20

  int r, init_size;
  Node*  root;
  ScanEnv  scan_env = {0};
#ifdef USE_SUBEXP_CALL
  UnsetAddrList  uslist;
#endif

  if (IS_NOT_NULL(einfo)) einfo->par = (UChar* )NULL;

  scan_env.sourcefile = sourcefile;
  scan_env.sourceline = sourceline;
  reg->state = ONIG_STATE_COMPILING;

#ifdef ONIG_DEBUG
  print_enc_string(stderr, reg->enc, pattern, pattern_end);
#endif

  if (reg->alloc == 0) {
    init_size = (pattern_end - pattern) * 2;
    if (init_size <= 0) init_size = COMPILE_INIT_SIZE;
    r = BBUF_INIT(reg, init_size);
    if (r != 0) goto end;
  }
  else
    reg->used = 0;

  reg->num_mem            = 0;
  reg->num_repeat         = 0;
  reg->num_null_check     = 0;
  reg->repeat_range_alloc = 0;
  reg->repeat_range       = (OnigRepeatRange* )NULL;
#ifdef USE_COMBINATION_EXPLOSION_CHECK
  reg->num_comb_exp_check = 0;
#endif

  r = onig_parse_make_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)) {
    if (scan_env.num_named != scan_env.num_mem)
      r = disable_noname_group_capture(&root, reg, &scan_env);
    else
      r = numbered_ref_check(root);

    if (r != 0) goto err;
  }
#endif

#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);
    if (r != 0) goto err_unset;
    r = subexp_recursive_check_trav(root, &scan_env);
    if (r  < 0) goto err_unset;
    r = subexp_inf_recursive_check_trav(root, &scan_env);
    if (r != 0) goto err_unset;

    reg->num_call = scan_env.num_call;
  }
  else
    reg->num_call = 0;
#endif

  r = setup_tree(root, reg, 0, &scan_env);
  if (r != 0) goto err_unset;

#ifdef ONIG_DEBUG_PARSE_TREE
  print_tree(stderr, root);
#endif

  reg->capture_history  = scan_env.capture_history;
  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);
  else {
    reg->bt_mem_end  = scan_env.bt_mem_end;
    reg->bt_mem_end |= reg->capture_history;
  }

#ifdef USE_COMBINATION_EXPLOSION_CHECK
  if (scan_env.backrefed_mem == 0
#ifdef USE_SUBEXP_CALL
      || scan_env.num_call == 0
#endif
      ) {
    setup_comb_exp_check(root, 0, &scan_env);
#ifdef USE_SUBEXP_CALL
    if (scan_env.has_recursion != 0) {
      scan_env.num_comb_exp_check = 0;
    }
    else
#endif
    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) {
          scan_env.num_comb_exp_check = 0;
          break;
        }
      }
    }
  }

  reg->num_comb_exp_check = scan_env.num_comb_exp_check;
#endif

  clear_optimize_info(reg);
#ifndef ONIG_DONT_OPTIMIZE
  r = set_optimize_info_from_tree(root, reg, &scan_env);
  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;
  }

  r = compile_tree(root, reg);
  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;
    }
#endif

    if ((reg->num_repeat != 0) || (reg->bt_mem_end != 0))
      reg->stack_pop_level = STACK_POP_LEVEL_ALL;
    else {
      if (reg->bt_mem_start != 0)
        reg->stack_pop_level = STACK_POP_LEVEL_MEM_START;
      else
        reg->stack_pop_level = STACK_POP_LEVEL_FREE;
    }
  }
#ifdef USE_SUBEXP_CALL
  else if (scan_env.num_call > 0) {
    unset_addr_list_end(&uslist);
  }
#endif
  onig_node_free(root);

#ifdef ONIG_DEBUG_COMPILE
#ifdef USE_NAMED_GROUP
  onig_print_names(stderr, reg);
#endif
  print_compiled_byte_code_list(stderr, reg);
#endif

 end:
  reg->state = ONIG_STATE_NORMAL;
  return r;

 err_unset:
#ifdef USE_SUBEXP_CALL
  if (scan_env.num_call > 0) {
    unset_addr_list_end(&uslist);
  }
#endif
 err:
  if (IS_NOT_NULL(scan_env.error)) {
    if (IS_NOT_NULL(einfo)) {
      einfo->enc     = scan_env.enc;
      einfo->par     = scan_env.error;
      einfo->par_end = scan_env.error_end;
    }
  }

  onig_node_free(root);
  if (IS_NOT_NULL(scan_env.mem_nodes_dynamic))
      xfree(scan_env.mem_nodes_dynamic);
  return r;
}

#ifdef USE_RECOMPILE_API
extern int
onig_recompile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
            OnigOptionType option, OnigEncoding enc, OnigSyntaxType* syntax,
            OnigErrorInfo* einfo)
{
  int r;
  regex_t *new_reg;

  r = onig_new(&new_reg, pattern, pattern_end, option, enc, syntax, einfo);
  if (r) return r;
  if (ONIG_STATE(reg) == ONIG_STATE_NORMAL) {
    onig_transfer(reg, new_reg);
  }
  else {
    onig_chain_link_add(reg, new_reg);
  }
  return 0;
}
#endif

static int onig_inited = 0;

extern int
onig_reg_init(regex_t* reg, OnigOptionType option,
              OnigCaseFoldType case_fold_flag,
              OnigEncoding enc, const OnigSyntaxType* syntax)
{
  if (! onig_inited)
    onig_init();

  if (IS_NULL(reg))
    return ONIGERR_INVALID_ARGUMENT;

  if (ONIGENC_IS_UNDEF(enc))
    return ONIGERR_DEFAULT_ENCODING_IS_NOT_SETTED;

  if ((option & (ONIG_OPTION_DONT_CAPTURE_GROUP|ONIG_OPTION_CAPTURE_GROUP))
      == (ONIG_OPTION_DONT_CAPTURE_GROUP|ONIG_OPTION_CAPTURE_GROUP)) {
    return ONIGERR_INVALID_COMBINATION_OF_OPTIONS;
  }

  (reg)->state = ONIG_STATE_MODIFY;

  if ((option & ONIG_OPTION_NEGATE_SINGLELINE) != 0) {
    option |= syntax->options;
    option &= ~ONIG_OPTION_SINGLELINE;
  }
  else
    option |= syntax->options;

  (reg)->enc              = enc;
  (reg)->options          = option;
  (reg)->syntax           = syntax;
  (reg)->optimize         = 0;
  (reg)->exact            = (UChar* )NULL;
  (reg)->int_map          = (int* )NULL;
  (reg)->int_map_backward = (int* )NULL;
  (reg)->chain            = (regex_t* )NULL;

  (reg)->p                = (UChar* )NULL;
  (reg)->alloc            = 0;
  (reg)->used             = 0;
  (reg)->name_table       = (void* )NULL;

  (reg)->case_fold_flag   = case_fold_flag;
  return 0;
}

extern int
onig_new_without_alloc(regex_t* reg, const UChar* pattern,
          const UChar* pattern_end, OnigOptionType option, OnigEncoding enc,
          OnigSyntaxType* syntax, OnigErrorInfo* einfo)
{
  int r;

  r = onig_reg_init(reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
  if (r) return r;

  r = onig_compile(reg, pattern, pattern_end, einfo, NULL, 0);
  return r;
}

extern int
onig_new(regex_t** reg, const UChar* pattern, const UChar* pattern_end,
          OnigOptionType option, OnigEncoding enc, const OnigSyntaxType* syntax,
          OnigErrorInfo* einfo)
{
  int r;

  *reg = (regex_t* )xmalloc(sizeof(regex_t));
  if (IS_NULL(*reg)) return ONIGERR_MEMORY;

  r = onig_reg_init(*reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
  if (r) goto err;

  r = onig_compile(*reg, pattern, pattern_end, einfo, NULL, 0);
  if (r) {
  err:
    onig_free(*reg);
    *reg = NULL;
  }
  return r;
}


extern int
onig_init(void)
{
  if (onig_inited != 0)
    return 0;

  THREAD_SYSTEM_INIT;
  THREAD_ATOMIC_START;

  onig_inited = 1;

  onigenc_init();
  /* onigenc_set_default_caseconv_table((UChar* )0); */

#ifdef ONIG_DEBUG_STATISTICS
  onig_statistics_init();
#endif

  THREAD_ATOMIC_END;
  return 0;
}


extern int
onig_end(void)
{
  THREAD_ATOMIC_START;

#ifdef ONIG_DEBUG_STATISTICS
  onig_print_statistics(stderr);
#endif

#ifdef USE_SHARED_CCLASS_TABLE
  onig_free_shared_cclass_table();
#endif

#ifdef USE_PARSE_TREE_NODE_RECYCLE
  onig_free_node_list();
#endif

  onig_inited = 0;

  THREAD_ATOMIC_END;
  THREAD_SYSTEM_END;
  return 0;
}
#endif //ENABLE_REGEXP

#ifdef INCLUDE_ENCODING
extern int
onig_is_in_code_range(const UChar* p, OnigCodePoint code)
{
  OnigCodePoint n, *data;
  OnigCodePoint low, high, x;

  GET_CODE_POINT(n, p);
  data = (OnigCodePoint* )p;
  data++;

  for (low = 0, high = n; low < high; ) {
    x = (low + high) >> 1;
    if (code > data[x * 2 + 1])
      low = x + 1;
    else
      high = x;
  }

  return ((low < n && code >= data[low * 2]) ? 1 : 0);
}
#endif //INCLUDE_ENCODING

#ifdef ENABLE_REGEXP
extern int
onig_is_code_in_cc_len(int elen, OnigCodePoint code, CClassNode* cc)
{
  int found;

  if (elen > 1 || (code >= SINGLE_BYTE_SIZE)) {
    if (IS_NULL(cc->mbuf)) {
      found = 0;
    }
    else {
      found = (onig_is_in_code_range(cc->mbuf->p, code) != 0 ? 1 : 0);
    }
  }
  else {
    found = (BITSET_AT(cc->bs, code) == 0 ? 0 : 1);
  }

  if (IS_NCCLASS_NOT(cc))
    return !found;
  else
    return found;
}

extern int
onig_is_code_in_cc(OnigEncoding enc, OnigCodePoint code, CClassNode* cc)
{
  int len;

  if (ONIGENC_MBC_MINLEN(enc) > 1) {
    len = 2;
  }
  else {
    len = ONIGENC_CODE_TO_MBCLEN(enc, code);
  }
  return onig_is_code_in_cc_len(len, code, cc);
}


#ifdef ONIG_DEBUG

/* arguments type */
#define ARG_SPECIAL     -1
#define ARG_NON          0
#define ARG_RELADDR      1
#define ARG_ABSADDR      2
#define ARG_LENGTH       3
#define ARG_MEMNUM       4
#define ARG_OPTION       5
#define ARG_STATE_CHECK  6

OnigOpInfoType OnigOpInfo[] = {
  { OP_FINISH,            "finish",          ARG_NON },
  { OP_END,               "end",             ARG_NON },
  { OP_EXACT1,            "exact1",          ARG_SPECIAL },
  { OP_EXACT2,            "exact2",          ARG_SPECIAL },
  { OP_EXACT3,            "exact3",          ARG_SPECIAL },
  { OP_EXACT4,            "exact4",          ARG_SPECIAL },
  { OP_EXACT5,            "exact5",          ARG_SPECIAL },
  { OP_EXACTN,            "exactn",          ARG_SPECIAL },
  { OP_EXACTMB2N1,        "exactmb2-n1",     ARG_SPECIAL },
  { OP_EXACTMB2N2,        "exactmb2-n2",     ARG_SPECIAL },
  { OP_EXACTMB2N3,        "exactmb2-n3",     ARG_SPECIAL },
  { OP_EXACTMB2N,         "exactmb2-n",      ARG_SPECIAL },
  { OP_EXACTMB3N,         "exactmb3n"  ,     ARG_SPECIAL },
  { OP_EXACTMBN,          "exactmbn",        ARG_SPECIAL },
  { OP_EXACT1_IC,         "exact1-ic",       ARG_SPECIAL },
  { OP_EXACTN_IC,         "exactn-ic",       ARG_SPECIAL },
  { OP_CCLASS,            "cclass",          ARG_SPECIAL },
  { OP_CCLASS_MB,         "cclass-mb",       ARG_SPECIAL },
  { OP_CCLASS_MIX,        "cclass-mix",      ARG_SPECIAL },
  { OP_CCLASS_NOT,        "cclass-not",      ARG_SPECIAL },
  { OP_CCLASS_MB_NOT,     "cclass-mb-not",   ARG_SPECIAL },
  { OP_CCLASS_MIX_NOT,    "cclass-mix-not",  ARG_SPECIAL },
  { OP_CCLASS_NODE,       "cclass-node",     ARG_SPECIAL },
  { OP_ANYCHAR,           "anychar",         ARG_NON },
  { OP_ANYCHAR_ML,        "anychar-ml",      ARG_NON },
  { OP_ANYCHAR_STAR,      "anychar*",        ARG_NON },
  { OP_ANYCHAR_ML_STAR,   "anychar-ml*",     ARG_NON },
  { OP_ANYCHAR_STAR_PEEK_NEXT, "anychar*-peek-next", ARG_SPECIAL },
  { OP_ANYCHAR_ML_STAR_PEEK_NEXT, "anychar-ml*-peek-next", ARG_SPECIAL },
  { OP_WORD,                "word",            ARG_NON },
  { OP_NOT_WORD,            "not-word",        ARG_NON },
  { OP_WORD_BOUND,          "word-bound",      ARG_NON },
  { OP_NOT_WORD_BOUND,      "not-word-bound",  ARG_NON },
  { OP_WORD_BEGIN,          "word-begin",      ARG_NON },
  { OP_WORD_END,            "word-end",        ARG_NON },
  { OP_BEGIN_BUF,           "begin-buf",       ARG_NON },
  { OP_END_BUF,             "end-buf",         ARG_NON },
  { OP_BEGIN_LINE,          "begin-line",      ARG_NON },
  { OP_END_LINE,            "end-line",        ARG_NON },
  { OP_SEMI_END_BUF,        "semi-end-buf",    ARG_NON },
  { OP_BEGIN_POSITION,      "begin-position",  ARG_NON },
  { OP_BACKREF1,            "backref1",             ARG_NON },
  { OP_BACKREF2,            "backref2",             ARG_NON },
  { OP_BACKREFN,            "backrefn",             ARG_MEMNUM  },
  { OP_BACKREFN_IC,         "backrefn-ic",          ARG_SPECIAL },
  { OP_BACKREF_MULTI,       "backref_multi",        ARG_SPECIAL },
  { OP_BACKREF_MULTI_IC,    "backref_multi-ic",     ARG_SPECIAL },
  { OP_BACKREF_WITH_LEVEL,    "backref_at_level",     ARG_SPECIAL },
  { OP_MEMORY_START_PUSH,   "mem-start-push",       ARG_MEMNUM  },
  { OP_MEMORY_START,        "mem-start",            ARG_MEMNUM  },
  { OP_MEMORY_END_PUSH,     "mem-end-push",         ARG_MEMNUM  },
  { OP_MEMORY_END_PUSH_REC, "mem-end-push-rec",     ARG_MEMNUM  },
  { OP_MEMORY_END,          "mem-end",              ARG_MEMNUM  },
  { OP_MEMORY_END_REC,      "mem-end-rec",          ARG_MEMNUM  },
  { OP_SET_OPTION_PUSH,     "set-option-push",      ARG_OPTION  },
  { OP_SET_OPTION,          "set-option",           ARG_OPTION  },
  { OP_FAIL,                "fail",                 ARG_NON },
  { OP_JUMP,                "jump",                 ARG_RELADDR },
  { OP_PUSH,                "push",                 ARG_RELADDR },
  { OP_POP,                 "pop",                  ARG_NON },
  { OP_PUSH_OR_JUMP_EXACT1, "push-or-jump-e1",      ARG_SPECIAL },
  { OP_PUSH_IF_PEEK_NEXT,   "push-if-peek-next",    ARG_SPECIAL },
  { OP_REPEAT,              "repeat",               ARG_SPECIAL },
  { OP_REPEAT_NG,           "repeat-ng",            ARG_SPECIAL },
  { OP_REPEAT_INC,          "repeat-inc",           ARG_MEMNUM  },
  { 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_PUSH_POS,             "push-pos",             ARG_NON },
  { OP_POP_POS,              "pop-pos",              ARG_NON },
  { OP_PUSH_POS_NOT,         "push-pos-not",         ARG_RELADDR },
  { OP_FAIL_POS,             "fail-pos",             ARG_NON },
  { OP_PUSH_STOP_BT,         "push-stop-bt",         ARG_NON },
  { OP_POP_STOP_BT,          "pop-stop-bt",          ARG_NON },
  { OP_LOOK_BEHIND,          "look-behind",          ARG_SPECIAL },
  { OP_PUSH_LOOK_BEHIND_NOT, "push-look-behind-not", ARG_SPECIAL },
  { OP_FAIL_LOOK_BEHIND_NOT, "fail-look-behind-not", ARG_NON },
  { OP_CALL,                 "call",                 ARG_ABSADDR },
  { OP_RETURN,               "return",               ARG_NON },
  { OP_STATE_CHECK_PUSH,         "state-check-push",         ARG_SPECIAL },
  { OP_STATE_CHECK_PUSH_OR_JUMP, "state-check-push-or-jump", ARG_SPECIAL },
  { OP_STATE_CHECK,              "state-check",              ARG_STATE_CHECK },
  { OP_STATE_CHECK_ANYCHAR_STAR, "state-check-anychar*",     ARG_STATE_CHECK },
  { OP_STATE_CHECK_ANYCHAR_ML_STAR,
    "state-check-anychar-ml*", ARG_STATE_CHECK },
  { -1, "", ARG_NON }
};

static char*
op2name(int opcode)
{
  int i;

  for (i = 0; OnigOpInfo[i].opcode >= 0; i++) {
    if (opcode == OnigOpInfo[i].opcode)
      return OnigOpInfo[i].name;
  }
  return "";
}

static int
op2arg_type(int opcode)
{
  int i;

  for (i = 0; OnigOpInfo[i].opcode >= 0; i++) {
    if (opcode == OnigOpInfo[i].opcode)
      return OnigOpInfo[i].arg_type;
  }
  return ARG_SPECIAL;
}

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);
  while (len-- > 0) { fputc(*s++, f); }
}

static void
p_len_string(FILE* f, LengthType len, int mb_len, UChar* s)
{
  int x = len * mb_len;

  fprintf(f, ":%d:", len);
  while (x-- > 0) { fputc(*s++, f); }
}

extern void
onig_print_compiled_byte_code(FILE* f, UChar* bp, UChar* bpend, UChar** nextp,
                              OnigEncoding enc)
{
  int i, n, arg_type;
  RelAddrType addr;
  LengthType len;
  MemNumType mem;
  StateCheckNumType scn;
  OnigCodePoint code;
  UChar *q;

  fprintf(f, "[%s", op2name(*bp));
  arg_type = op2arg_type(*bp);
  if (arg_type != ARG_SPECIAL) {
    bp++;
    switch (arg_type) {
    case ARG_NON:
      break;
    case ARG_RELADDR:
      GET_RELADDR_INC(addr, bp);
      fprintf(f, ":(%d)", addr);
      break;
    case ARG_ABSADDR:
      GET_ABSADDR_INC(addr, bp);
      fprintf(f, ":(%d)", addr);
      break;
    case ARG_LENGTH:
      GET_LENGTH_INC(len, bp);
      fprintf(f, ":%d", len);
      break;
    case ARG_MEMNUM:
      mem = *((MemNumType* )bp);
      bp += SIZE_MEMNUM;
      fprintf(f, ":%d", mem);
      break;
    case ARG_OPTION:
      {
        OnigOptionType option = *((OnigOptionType* )bp);
        bp += SIZE_OPTION;
        fprintf(f, ":%d", option);
      }
      break;

    case ARG_STATE_CHECK:
      scn = *((StateCheckNumType* )bp);
      bp += SIZE_STATE_CHECK_NUM;
      fprintf(f, ":%d", scn);
      break;
    }
  }
  else {
    switch (*bp++) {
    case OP_EXACT1:
    case OP_ANYCHAR_STAR_PEEK_NEXT:
    case OP_ANYCHAR_ML_STAR_PEEK_NEXT:
      p_string(f, 1, bp++); break;
    case OP_EXACT2:
      p_string(f, 2, bp); bp += 2; break;
    case OP_EXACT3:
      p_string(f, 3, bp); bp += 3; break;
    case OP_EXACT4:
      p_string(f, 4, bp); bp += 4; break;
    case OP_EXACT5:
      p_string(f, 5, bp); bp += 5; break;
    case OP_EXACTN:
      GET_LENGTH_INC(len, bp);
      p_len_string(f, len, 1, bp);
      bp += len;
      break;

    case OP_EXACTMB2N1:
      p_string(f, 2, bp); bp += 2; break;
    case OP_EXACTMB2N2:
      p_string(f, 4, bp); bp += 4; break;
    case OP_EXACTMB2N3:
      p_string(f, 6, bp); bp += 6; break;
    case OP_EXACTMB2N:
      GET_LENGTH_INC(len, bp);
      p_len_string(f, len, 2, bp);
      bp += len * 2;
      break;
    case OP_EXACTMB3N:
      GET_LENGTH_INC(len, bp);
      p_len_string(f, len, 3, bp);
      bp += len * 3;
      break;
    case OP_EXACTMBN:
      {
        int mb_len;

        GET_LENGTH_INC(mb_len, bp);
        GET_LENGTH_INC(len, bp);
        fprintf(f, ":%d:%d:", mb_len, len);
        n = len * mb_len;
        while (n-- > 0) { fputc(*bp++, f); }
      }
      break;

    case OP_EXACT1_IC:
      len = enclen(enc, bp, bpend);
      p_string(f, len, bp);
      bp += len;
      break;
    case OP_EXACTN_IC:
      GET_LENGTH_INC(len, bp);
      p_len_string(f, len, 1, bp);
      bp += len;
      break;

    case OP_CCLASS:
      n = bitset_on_num((BitSetRef )bp);
      bp += SIZE_BITSET;
      fprintf(f, ":%d", n);
      break;

    case OP_CCLASS_NOT:
      n = bitset_on_num((BitSetRef )bp);
      bp += SIZE_BITSET;
      fprintf(f, ":%d", n);
      break;

    case OP_CCLASS_MB:
    case OP_CCLASS_MB_NOT:
      GET_LENGTH_INC(len, bp);
      q = bp;
#ifndef PLATFORM_UNALIGNED_WORD_ACCESS
      ALIGNMENT_RIGHT(q);
#endif
      GET_CODE_POINT(code, q);
      bp += len;
      fprintf(f, ":%d:%d", (int )code, len);
      break;

    case OP_CCLASS_MIX:
    case OP_CCLASS_MIX_NOT:
      n = bitset_on_num((BitSetRef )bp);
      bp += SIZE_BITSET;
      GET_LENGTH_INC(len, bp);
      q = bp;
#ifndef PLATFORM_UNALIGNED_WORD_ACCESS
      ALIGNMENT_RIGHT(q);
#endif
      GET_CODE_POINT(code, q);
      bp += len;
      fprintf(f, ":%d:%d:%d", n, (int )code, len);
      break;

    case OP_CCLASS_NODE:
      {
        CClassNode *cc;

        GET_POINTER_INC(cc, bp);
        n = bitset_on_num(cc->bs);
        fprintf(f, ":%u:%d", (unsigned int )cc, n);
      }
      break;

    case OP_BACKREFN_IC:
      mem = *((MemNumType* )bp);
      bp += SIZE_MEMNUM;
      fprintf(f, ":%d", mem);
      break;

    case OP_BACKREF_MULTI_IC:
    case OP_BACKREF_MULTI:
      fputs(" ", f);
      GET_LENGTH_INC(len, bp);
      for (i = 0; i < len; i++) {
        GET_MEMNUM_INC(mem, bp);
        if (i > 0) fputs(", ", f);
        fprintf(f, "%d", mem);
      }
      break;

    case OP_BACKREF_WITH_LEVEL:
      {
        OnigOptionType option;
        LengthType level;

        GET_OPTION_INC(option, bp);
        fprintf(f, ":%d", option);
        GET_LENGTH_INC(level, bp);
        fprintf(f, ":%d", level);

        fputs(" ", f);
        GET_LENGTH_INC(len, bp);
        for (i = 0; i < len; i++) {
          GET_MEMNUM_INC(mem, bp);
          if (i > 0) fputs(", ", f);
          fprintf(f, "%d", mem);
        }
      }
      break;

    case OP_REPEAT:
    case OP_REPEAT_NG:
      {
        mem = *((MemNumType* )bp);
        bp += SIZE_MEMNUM;
        addr = *((RelAddrType* )bp);
        bp += SIZE_RELADDR;
        fprintf(f, ":%d:%d", mem, addr);
      }
      break;

    case OP_PUSH_OR_JUMP_EXACT1:
    case OP_PUSH_IF_PEEK_NEXT:
      addr = *((RelAddrType* )bp);
      bp += SIZE_RELADDR;
      fprintf(f, ":(%d)", addr);
      p_string(f, 1, bp);
      bp += 1;
      break;

    case OP_LOOK_BEHIND:
      GET_LENGTH_INC(len, bp);
      fprintf(f, ":%d", len);
      break;

    case OP_PUSH_LOOK_BEHIND_NOT:
      GET_RELADDR_INC(addr, bp);
      GET_LENGTH_INC(len, bp);
      fprintf(f, ":%d:(%d)", len, addr);
      break;

    case OP_STATE_CHECK_PUSH:
    case OP_STATE_CHECK_PUSH_OR_JUMP:
      scn = *((StateCheckNumType* )bp);
      bp += SIZE_STATE_CHECK_NUM;
      addr = *((RelAddrType* )bp);
      bp += SIZE_RELADDR;
      fprintf(f, ":%d:(%d)", scn, addr);
      break;

    default:
      fprintf(stderr, "onig_print_compiled_byte_code: undefined code %d\n",
              *--bp);
    }
  }
  fputs("]", f);
  if (nextp) *nextp = bp;
}

static void
print_compiled_byte_code_list(FILE* f, regex_t* reg)
{
  int ncode;
  UChar* bp = reg->p;
  UChar* end = reg->p + reg->used;

  fprintf(f, "code length: %d\n", reg->used);

  ncode = 0;
  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, end, &bp, reg->enc);
  }

  fprintf(f, "\n");
}

static void
print_indent_tree(FILE* f, Node* node, int indent)
{
  int i, type;
  int add = 3;
  UChar* p;

  Indent(f, indent);
  if (IS_NULL(node)) {
    fprintf(f, "ERROR: null node!!!\n");
    exit (0);
  }

  type = NTYPE(node);
  switch (type) {
  case NT_LIST:
  case NT_ALT:
    if (NTYPE(node) == NT_LIST)
      fprintf(f, "<list:%x>\n", (int )node);
    else
      fprintf(f, "<alt:%x>\n", (int )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));
        exit(0);
      }
      print_indent_tree(f, NCAR(node), indent + add);
    }
    break;

  case NT_STR:
    fprintf(f, "<string%s:%x>",
            (NSTRING_IS_RAW(node) ? "-raw" : ""), (int )node);
    for (p = NSTR(node)->s; p < NSTR(node)->end; p++) {
      if (*p >= 0x20 && *p < 0x7f)
        fputc(*p, f);
      else {
        fprintf(f, " 0x%02x", *p);
      }
    }
    break;

  case NT_CCLASS:
    fprintf(f, "<cclass:%x>", (int )node);
    if (IS_NCCLASS_NOT(NCCLASS(node))) fputs(" not", f);
    if (NCCLASS(node)->mbuf) {
      BBuf* bbuf = NCCLASS(node)->mbuf;
      for (i = 0; i < bbuf->used; i++) {
        if (i > 0) fprintf(f, ",");
        fprintf(f, "%0x", bbuf->p[i]);
      }
    }
    break;

  case NT_CTYPE:
    fprintf(f, "<ctype:%x> ", (int )node);
    switch (NCTYPE(node)->ctype) {
    case ONIGENC_CTYPE_WORD:
      if (NCTYPE(node)->is_not != 0)
        fputs("not word",       f);
      else
        fputs("word",           f);
      break;

    default:
      fprintf(f, "ERROR: undefined ctype.\n");
      exit(0);
    }
    break;

  case NT_CANY:
    fprintf(f, "<anychar:%x>", (int )node);
    break;

  case NT_ANCHOR:
    fprintf(f, "<anchor:%x> ", (int )node);
    switch (NANCHOR(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;
    case ANCHOR_END_LINE:       fputs("end line",       f); break;
    case ANCHOR_SEMI_END_BUF:   fputs("semi end buf",   f); break;
    case ANCHOR_BEGIN_POSITION: fputs("begin position", f); break;

    case ANCHOR_WORD_BOUND:      fputs("word bound",     f); break;
    case ANCHOR_NOT_WORD_BOUND:  fputs("not word bound", f); break;
#ifdef USE_WORD_BEGIN_END
    case ANCHOR_WORD_BEGIN:      fputs("word begin", f);     break;
    case ANCHOR_WORD_END:        fputs("word end", f);       break;
#endif
    case ANCHOR_PREC_READ:       fputs("prec read",      f); break;
    case ANCHOR_PREC_READ_NOT:   fputs("prec read not",  f); break;
    case ANCHOR_LOOK_BEHIND:     fputs("look_behind",    f); break;
    case ANCHOR_LOOK_BEHIND_NOT: fputs("look_behind_not",f); break;

    default:
      fprintf(f, "ERROR: undefined anchor type.\n");
      break;
    }
    break;

  case NT_BREF:
    {
      int* p;
      BRefNode* br = NBREF(node);
      p = BACKREFS_P(br);
      fprintf(f, "<backref:%x>", (int )node);
      for (i = 0; i < br->back_num; i++) {
        if (i > 0) fputs(", ", f);
        fprintf(f, "%d", p[i]);
      }
    }
    break;

#ifdef USE_SUBEXP_CALL
  case NT_CALL:
    {
      CallNode* cn = NCALL(node);
      fprintf(f, "<call:%x>", (int )node);
      p_string(f, cn->name_end - cn->name, cn->name);
    }
    break;
#endif

  case NT_QTFR:
    fprintf(f, "<quantifier:%x>{%d,%d}%s\n", (int )node,
            NQTFR(node)->lower, NQTFR(node)->upper,
            (NQTFR(node)->greedy ? "" : "?"));
    print_indent_tree(f, NQTFR(node)->target, indent + add);
    break;

  case NT_ENCLOSE:
    fprintf(f, "<enclose:%x> ", (int )node);
    switch (NENCLOSE(node)->type) {
    case ENCLOSE_OPTION:
      fprintf(f, "option:%d\n", NENCLOSE(node)->option);
      print_indent_tree(f, NENCLOSE(node)->target, indent + add);
      break;
    case ENCLOSE_MEMORY:
      fprintf(f, "memory:%d", NENCLOSE(node)->regnum);
      break;
    case ENCLOSE_STOP_BACKTRACK:
      fprintf(f, "stop-bt");
      break;

    default:
      break;
    }
    fprintf(f, "\n");
    print_indent_tree(f, NENCLOSE(node)->target, indent + add);
    break;

  default:
    fprintf(f, "print_indent_tree: undefined node type %d\n", NTYPE(node));
    break;
  }

  if (type != NT_LIST && type != NT_ALT && type != NT_QTFR &&
      type != NT_ENCLOSE)
    fprintf(f, "\n");
  fflush(f);
}
#endif /* ONIG_DEBUG */

#ifdef ONIG_DEBUG_PARSE_TREE
static void
print_tree(FILE* f, Node* node)
{
  print_indent_tree(f, node, 0);
}
#endif
#endif //ENABLE_REGEXP