/regcomp.c

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/**********************************************************************
  regcomp.c -  Onigmo (Oniguruma-mod) (regular expression library)
**********************************************************************/
/*-
 * Copyright (c) 2002-2013  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
 * Copyright (c) 2011-2016  K.Takata  <kentkt AT csc 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 "regparse.h"

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

#if 0
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;
}
#endif

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 < 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

// Attempt to right size allocated buffers for a regex post compile
static void
onig_reg_resize(regex_t *reg)
{
  resize:
    if (reg->alloc > reg->used) {
      unsigned char *new_ptr = xrealloc(reg->p, reg->used);
      // Skip the right size optimization if memory allocation fails
      if (new_ptr) {
        reg->alloc = reg->used;
        reg->p = new_ptr;
      }
    }
    if (reg->chain) {
      reg = reg->chain;
      goto resize;
    }
}

extern int
onig_bbuf_init(BBuf* buf, OnigDistance 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 = (unsigned int )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, OnigDistance 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;
}

#if 0
static int
add_pointer(regex_t* reg, void* addr)
{
  PointerType ptr = (PointerType )addr;

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

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, OnigDistance 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, OnigDistance byte_len, int ignore_case)
{
  int op;
  OnigDistance str_len = (byte_len + mb_len - 1) / mb_len;

  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 byte_len,
                          regex_t* reg ARG_UNUSED, int ignore_case)
{
  int len;
  int op = select_str_opcode(mb_len, byte_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 += (int )byte_len;
  return len;
}

static int
add_compile_string(UChar* s, int mb_len, OnigDistance byte_len,
                   regex_t* reg, int ignore_case)
{
  int op = select_str_opcode(mb_len, byte_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, byte_len);
    else
      add_length(reg, byte_len / mb_len);
  }

  add_bytes(reg, s, byte_len);
  return 0;
}


static int
compile_length_string_node(Node* node, regex_t* reg)
{
  int rlen, r, len, prev_len, blen, 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;
  blen = prev_len;
  rlen = 0;

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

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

      prev  = p;
      blen  = len;
      prev_len = len;
    }

    p += len;
  }
  return add_compile_string(prev, prev_len, blen, 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_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_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_referred != 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_referred != 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) {
#ifdef USE_OP_PUSH_OR_JUMP_EXACT
      if (IS_NOT_NULL(qn->head_exact))
	len += SIZE_OP_PUSH_OR_JUMP_EXACT1 + mod_tlen + SIZE_OP_JUMP;
      else
#endif
      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_referred != 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) {
#ifdef USE_OP_PUSH_OR_JUMP_EXACT
	if (IS_NOT_NULL(qn->head_exact))
	  r = add_opcode_rel_addr(reg, OP_JUMP, SIZE_OP_PUSH_OR_JUMP_EXACT1);
	else
#endif
	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) {
#ifdef USE_OP_PUSH_OR_JUMP_EXACT
      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
#endif
      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_referred != 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 if (IS_ENCLOSE_RECURSION(node)) {
      len = SIZE_OP_MEMORY_START_PUSH;
      len += tlen + (BIT_STATUS_AT(reg->bt_mem_end, node->regnum)
		     ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_REC);
    }
    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;

  case ENCLOSE_CONDITION:
    len = SIZE_OP_CONDITION;
    if (NTYPE(node->target) == NT_ALT) {
      Node* x = node->target;

      tlen = compile_length_tree(NCAR(x), reg); /* yes-node */
      if (tlen < 0) return tlen;
      len += tlen + SIZE_OP_JUMP;
      if (NCDR(x) == NULL) return ONIGERR_PARSER_BUG;
      x = NCDR(x);
      tlen = compile_length_tree(NCAR(x), reg); /* no-node */
      if (tlen < 0) return tlen;
      len += tlen;
      if (NCDR(x) != NULL) return ONIGERR_INVALID_CONDITION_PATTERN;
    }
    else {
      return ONIGERR_PARSER_BUG;
    }
    break;

  case ENCLOSE_ABSENT:
    len = SIZE_OP_PUSH_ABSENT_POS + SIZE_OP_ABSENT + tlen + SIZE_OP_ABSENT_END;
    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 if (IS_ENCLOSE_RECURSION(node)) {
      if (BIT_STATUS_AT(reg->bt_mem_end, node->regnum))
	r = add_opcode(reg, OP_MEMORY_END_PUSH_REC);
      else
	r = add_opcode(reg, OP_MEMORY_END_REC);
      if (r) return r;
      r = add_mem_num(reg, node->regnum);
    }
    else
#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;

  case ENCLOSE_CONDITION:
    r = add_opcode(reg, OP_CONDITION);
    if (r) return r;
    r = add_mem_num(reg, node->regnum);
    if (r) return r;

    if (NTYPE(node->target) == NT_ALT) {
      Node* x = node->target;
      int len2;

      len = compile_length_tree(NCAR(x), reg);  /* yes-node */
      if (len < 0) return len;
      if (NCDR(x) == NULL) return ONIGERR_PARSER_BUG;
      x = NCDR(x);
      len2 = compile_length_tree(NCAR(x), reg); /* no-node */
      if (len2 < 0) return len2;
      if (NCDR(x) != NULL) return ONIGERR_INVALID_CONDITION_PATTERN;

      x = node->target;
      r = add_rel_addr(reg, len + SIZE_OP_JUMP);
      if (r) return r;
      r = compile_tree(NCAR(x), reg);   /* yes-node */
      if (r) return r;
      r = add_opcode_rel_addr(reg, OP_JUMP, len2);
      if (r) return r;
      x = NCDR(x);
      r = compile_tree(NCAR(x), reg);   /* no-node */
    }
    else {
      return ONIGERR_PARSER_BUG;
    }
    break;

  case ENCLOSE_ABSENT:
    len = compile_length_tree(node->target, reg);
    if (len < 0) return len;

    r = add_opcode(reg, OP_PUSH_ABSENT_POS);
    if (r) return r;
    r = add_opcode_rel_addr(reg, OP_ABSENT, len + SIZE_OP_ABSENT_END);
    if (r) return r;
    r = compile_tree(node->target, reg);
    if (r) return r;
    r = add_opcode(reg, OP_ABSENT_END);
    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:
    if (node->ascii_range)    r = add_opcode(reg, OP_ASCII_WORD_BOUND);
    else                      r = add_opcode(reg, OP_WORD_BOUND);
    break;
  case ANCHOR_NOT_WORD_BOUND:
    if (node->ascii_range)    r = add_opcode(reg, OP_NOT_ASCII_WORD_BOUND);
    else                      r = add_opcode(reg, OP_NOT_WORD_BOUND);
    break;
#ifdef USE_WORD_BEGIN_END
  case ANCHOR_WORD_BEGIN:
    if (node->ascii_range)    r = add_opcode(reg, OP_ASCII_WORD_BEGIN);
    else                      r = add_opcode(reg, OP_WORD_BEGIN);
    break;
  case ANCHOR_WORD_END:
    if (node->ascii_range)    r = add_opcode(reg, OP_ASCII_WORD_END);
    else                      r = add_opcode(reg, OP_WORD_END);
    break;
#endif
  case ANCHOR_KEEP:           r = add_opcode(reg, OP_KEEP);           break;

  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 = 0;
      len = 0;
      do {
	r = compile_length_tree(NCAR(node), reg);
	if (r < 0) return r;
	len += r;
	n++;
      } while (IS_NOT_NULL(node = NCDR(node)));
      r = len;
      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)->ascii_range != 0) {
	  if (NCTYPE(node)->not != 0)  op = OP_NOT_ASCII_WORD;
	  else                         op = OP_ASCII_WORD;
	}
	else {
	  if (NCTYPE(node)->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;
	}
	else if (en->regnum != 0) {
	  *plink = en->target;
	  en->target = NULL_NODE;
	  onig_node_free(node);
	  r = noname_disable_map(plink, map, counter);
	  break;
	}
      }
      r = noname_disable_map(&(en->target), map, counter);
    }
    break;

  case NT_ANCHOR:
    if (NANCHOR(node)->target)
      r = noname_disable_map(&(NANCHOR(node)->target), map, counter);
    break;

  default:
    break;
  }

  return r;
}

static int
renumber_node_backref(Node* node, GroupNumRemap* map, const int num_mem)
{
  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++) {
    if (backs[i] > num_mem)  return ONIGERR_INVALID_BACKREF;
    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, const int num_mem)
{
  int r = 0;

  switch (NTYPE(node)) {
  case NT_LIST:
  case NT_ALT:
    do {
      r = renumber_by_map(NCAR(node), map, num_mem);
    } while (r == 0 && IS_NOT_NULL(node = NCDR(node)));
    break;
  case NT_QTFR:
    r = renumber_by_map(NQTFR(node)->target, map, num_mem);
    break;
  case NT_ENCLOSE:
    {
      EncloseNode* en = NENCLOSE(node);
      if (en->type == ENCLOSE_CONDITION) {
	if (en->regnum > num_mem)  return ONIGERR_INVALID_BACKREF;
	en->regnum = map[en->regnum].new_val;
      }
      r = renumber_by_map(en->target, map, num_mem);
    }
    break;

  case NT_BREF:
    r = renumber_node_backref(node, map, num_mem);
    break;

  case NT_ANCHOR:
    if (NANCHOR(node)->target)
      r = renumber_by_map(NANCHOR(node)->target, map, num_mem);
    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;

  case NT_ANCHOR:
    if (NANCHOR(node)->target)
      r = numbered_ref_check(NANCHOR(node)->target);
    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, env->num_mem);
  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 < u…