diff --git a/ChangeLog b/ChangeLog
index b28a2386b31fc2..4a56a148bc75f4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+Thu Feb 17 22:15:34 2005  K.Kosako <sndgk@ybb.ne.jp>
+
+	* ext/strscan/strscan.c: calls Oniguruma API directly.
+
+Thu Feb 17 21:53:12 2005  K.Kosako <sndgk@ybb.ne.jp>
+
+	* common.mk, LEGAL: remove reggnu.c.
+
+Thu Feb 17 21:53:12 2005  Kazuo Saito <ksaito@uranus.dti.ne.jp>
+
+	* gc.c, re.c: now ruby calls Oniguruma API directly, bypassing
+	  GNU compatible APIs.
+
 Thu Feb 17 20:09:23 2005  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
 
 	* lib/drb/drb.rb (DRbServer.default_safe_level): fix typo.
diff --git a/LEGAL b/LEGAL
index 121c5a7184340b..852a6bdf606903 100644
--- a/LEGAL
+++ b/LEGAL
@@ -12,7 +12,6 @@ regenc.[ch]:
 regerror.c:
 regex.c:
 regexec.c:
-reggnu.c:
 regint.h:
 regparse.[ch]:
 ascii.c:
@@ -20,11 +19,11 @@ euc_jp.c:
 sjis.c:
 utf8.c:
 
-Oniguruma  ----   (C) K.Kosako <kosako@sofnec.co.jp>
+Oniguruma  ----   (C) K.Kosako <sndgk393 AT ybb DOT ne DOT jp>
 
 http://www.ruby-lang.org/cgi-bin/cvsweb.cgi/oniguruma/
 http://www.freebsd.org/cgi/cvsweb.cgi/ports/devel/oniguruma/
-http://www.geocities.jp/kosako1/oniguruma/
+http://www.geocities.jp/kosako3/oniguruma/
 
    When this software is partly used or it is distributed with Ruby, 
    this of Ruby follows the license of Ruby.
diff --git a/common.mk b/common.mk
index 88f8afec82132c..86dd449028a57a 100644
--- a/common.mk
+++ b/common.mk
@@ -38,7 +38,6 @@ OBJS	      = array.$(OBJEXT) \
 		regenc.$(OBJEXT) \
 		regerror.$(OBJEXT) \
 		regexec.$(OBJEXT) \
-		reggnu.$(OBJEXT) \
 		regparse.$(OBJEXT) \
 		ruby.$(OBJEXT) \
 		signal.$(OBJEXT) \
@@ -260,9 +259,6 @@ regerror.$(OBJEXT): {$(VPATH)}regerror.c {$(VPATH)}regint.h \
   {$(VPATH)}regenc.h {$(VPATH)}oniguruma.h config.h
 regexec.$(OBJEXT): {$(VPATH)}regexec.c {$(VPATH)}regint.h \
   {$(VPATH)}regenc.h {$(VPATH)}oniguruma.h config.h
-reggnu.$(OBJEXT): {$(VPATH)}reggnu.c {$(VPATH)}regint.h \
-  {$(VPATH)}regenc.h {$(VPATH)}oniguruma.h {$(VPATH)}oniggnu.h \
-  config.h
 regparse.$(OBJEXT): {$(VPATH)}regparse.c {$(VPATH)}oniguruma.h \
   {$(VPATH)}regint.h {$(VPATH)}regparse.h {$(VPATH)}regenc.h config.h
 ruby.$(OBJEXT): {$(VPATH)}ruby.c {$(VPATH)}ruby.h config.h \
diff --git a/ext/strscan/strscan.c b/ext/strscan/strscan.c
index db1a9c64e6bc3a..158fab321fa0d7 100644
--- a/ext/strscan/strscan.c
+++ b/ext/strscan/strscan.c
@@ -171,7 +171,7 @@ static void
 strscan_free(p)
     struct strscanner *p;
 {
-    re_free_registers(&(p->regs));
+    onig_region_free(&(p->regs), 0);
     memset(p, sizeof(struct strscanner), 0);
     free(p);
 }
@@ -440,17 +440,15 @@ strscan_do_scan(self, regex, succptr, getstr, headonly)
     }
     strscan_prepare_re(regex);
     if (headonly) {
-        ret = re_match(RREGEXP(regex)->ptr,
-                       CURPTR(p), S_RESTLEN(p),
-                       0,
-                       &(p->regs));
+        ret = onig_match(RREGEXP(regex)->ptr, (UChar* )CURPTR(p),
+                         (UChar* )(CURPTR(p) + S_RESTLEN(p)),
+                         (UChar* )CURPTR(p), &(p->regs), ONIG_OPTION_NONE);
     }
     else {
-        ret = re_search(RREGEXP(regex)->ptr,
-                        CURPTR(p), S_RESTLEN(p),
-                        0,
-                        S_RESTLEN(p),
-                        &(p->regs));
+        ret = onig_search(RREGEXP(regex)->ptr,
+                          (UChar* )CURPTR(p), (UChar* )(CURPTR(p) + S_RESTLEN(p)),
+                          (UChar* )CURPTR(p), (UChar* )(CURPTR(p) + S_RESTLEN(p)),
+                          &(p->regs), ONIG_OPTION_NONE);
     }
 
     if (ret == -2) rb_raise(ScanError, "regexp buffer overflow");
diff --git a/gc.c b/gc.c
index 7aa42da67f339d..4197defda4747e 100644
--- a/gc.c
+++ b/gc.c
@@ -52,7 +52,6 @@ extern unsigned long __libc_ia64_register_backing_store_base;
 #include <windows.h>
 #endif
 
-void re_free_registers _((struct re_registers*));
 int rb_io_fptr_finalize _((struct OpenFile*));
 
 #if !defined(setjmp) && defined(HAVE__SETJMP)
@@ -1166,7 +1165,7 @@ obj_free(obj)
 	break;
       case T_REGEXP:
 	if (RANY(obj)->as.regexp.ptr) {
-	    re_free_pattern(RANY(obj)->as.regexp.ptr);
+	    onig_free(RANY(obj)->as.regexp.ptr);
 	}
 	if (RANY(obj)->as.regexp.str) {
 	    RUBY_CRITICAL(free(RANY(obj)->as.regexp.str));
@@ -1184,7 +1183,7 @@ obj_free(obj)
 	break;
       case T_MATCH:
 	if (RANY(obj)->as.match.regs) {
-	    re_free_registers(RANY(obj)->as.match.regs);
+	    onig_region_free(RANY(obj)->as.match.regs, 0);
 	    RUBY_CRITICAL(free(RANY(obj)->as.match.regs));
 	}
 	break;
diff --git a/re.c b/re.c
index b8bb851be108b1..8de3ddf8fa41b8 100644
--- a/re.c
+++ b/re.c
@@ -208,16 +208,16 @@ kcode_set_option(re)
     if (reg_kcode == curr_kcode) return;
     switch (curr_kcode) {
       case KCODE_NONE:
-	re_mbcinit(MBCTYPE_ASCII);
+	onigenc_set_default_encoding(ONIG_ENCODING_ASCII);
 	break;
       case KCODE_EUC:
-	re_mbcinit(MBCTYPE_EUC);
+	onigenc_set_default_encoding(ONIG_ENCODING_EUC_JP);
 	break;
       case KCODE_SJIS:
-	re_mbcinit(MBCTYPE_SJIS);
+	onigenc_set_default_encoding(ONIG_ENCODING_SJIS);
 	break;
       case KCODE_UTF8:
-	re_mbcinit(MBCTYPE_UTF8);
+	onigenc_set_default_encoding(ONIG_ENCODING_UTF8);
 	break;
     }
 }
@@ -228,16 +228,16 @@ kcode_reset_option()
     if (reg_kcode == curr_kcode) return;
     switch (reg_kcode) {
       case KCODE_NONE:
-	re_mbcinit(MBCTYPE_ASCII);
+	onigenc_set_default_encoding(ONIG_ENCODING_ASCII);
 	break;
       case KCODE_EUC:
-	re_mbcinit(MBCTYPE_EUC);
+	onigenc_set_default_encoding(ONIG_ENCODING_EUC_JP);
 	break;
       case KCODE_SJIS:
-	re_mbcinit(MBCTYPE_SJIS);
+	onigenc_set_default_encoding(ONIG_ENCODING_SJIS);
 	break;
       case KCODE_UTF8:
-	re_mbcinit(MBCTYPE_UTF8);
+	onigenc_set_default_encoding(ONIG_ENCODING_UTF8);
 	break;
     }
 }
@@ -335,11 +335,11 @@ rb_reg_desc(s, len, re)
     rb_str_buf_cat2(str, "/");
     if (re) {
 	rb_reg_check(re);
-	if (RREGEXP(re)->ptr->options & RE_OPTION_MULTILINE)
+	if (RREGEXP(re)->ptr->options & ONIG_OPTION_MULTILINE)
 	    rb_str_buf_cat2(str, "m");
-	if (RREGEXP(re)->ptr->options & RE_OPTION_IGNORECASE)
+	if (RREGEXP(re)->ptr->options & ONIG_OPTION_IGNORECASE)
 	    rb_str_buf_cat2(str, "i");
-	if (RREGEXP(re)->ptr->options & RE_OPTION_EXTENDED)
+	if (RREGEXP(re)->ptr->options & ONIG_OPTION_EXTEND)
 	    rb_str_buf_cat2(str, "x");
 
 	if (FL_TEST(re, KCODE_FIXED)) {
@@ -430,7 +430,7 @@ rb_reg_to_s(re)
     VALUE re;
 {
     int options;
-    const int embeddable = RE_OPTION_MULTILINE|RE_OPTION_IGNORECASE|RE_OPTION_EXTENDED;
+    const int embeddable = ONIG_OPTION_MULTILINE|ONIG_OPTION_IGNORECASE|ONIG_OPTION_EXTEND;
     long len;
     const char* ptr;
     VALUE str = rb_str_buf_new2("(?");
@@ -447,13 +447,13 @@ rb_reg_to_s(re)
 	if ((len -= 2) > 0) {
 	    do {
 		if (*ptr == 'm') {
-		    options |= RE_OPTION_MULTILINE;
+		    options |= ONIG_OPTION_MULTILINE;
 		}
 		else if (*ptr == 'i') {
-		    options |= RE_OPTION_IGNORECASE;
+		    options |= ONIG_OPTION_IGNORECASE;
 		}
 		else if (*ptr == 'x') {
-		    options |= RE_OPTION_EXTENDED;
+		    options |= ONIG_OPTION_EXTEND;
 		}
 		else break;
 		++ptr;
@@ -464,13 +464,13 @@ rb_reg_to_s(re)
 	    --len;
 	    do {
 		if (*ptr == 'm') {
-		    options &= ~RE_OPTION_MULTILINE;
+		    options &= ~ONIG_OPTION_MULTILINE;
 		}
 		else if (*ptr == 'i') {
-		    options &= ~RE_OPTION_IGNORECASE;
+		    options &= ~ONIG_OPTION_IGNORECASE;
 		}
 		else if (*ptr == 'x') {
-		    options &= ~RE_OPTION_EXTENDED;
+		    options &= ~ONIG_OPTION_EXTEND;
 		}
 		else break;
 		++ptr;
@@ -485,12 +485,17 @@ rb_reg_to_s(re)
 	    int r;
 	    Regexp *rp;
 	    kcode_set_option(re);
-	    r = re_alloc_pattern(&rp);
+            r = onig_alloc_init(&rp, ONIG_OPTION_DEFAULT,
+                                ONIGENC_AMBIGUOUS_MATCH_DEFAULT,
+                                onigenc_get_default_encoding(),
+                                OnigDefaultSyntax);
 	    if (r == 0) {
-		err = (re_compile_pattern(++ptr, len -= 2, rp, NULL) != 0);
+		 ++ptr;
+ 		 len -= 2;
+		 err = (onig_compile(rp, ptr, ptr + len, NULL) != 0);
 	    }
 	    kcode_reset_option();
-	    re_free_pattern(rp);
+	    onig_free(rp);
 	}
 	if (err) {
 	    options = RREGEXP(re)->ptr->options;
@@ -499,15 +504,15 @@ rb_reg_to_s(re)
 	}
     }
 
-    if (options & RE_OPTION_MULTILINE) rb_str_buf_cat2(str, "m");
-    if (options & RE_OPTION_IGNORECASE) rb_str_buf_cat2(str, "i");
-    if (options & RE_OPTION_EXTENDED) rb_str_buf_cat2(str, "x");
+    if (options & ONIG_OPTION_MULTILINE) rb_str_buf_cat2(str, "m");
+    if (options & ONIG_OPTION_IGNORECASE) rb_str_buf_cat2(str, "i");
+    if (options & ONIG_OPTION_EXTEND) rb_str_buf_cat2(str, "x");
 
     if ((options & embeddable) != embeddable) {
 	rb_str_buf_cat2(str, "-");
-	if (!(options & RE_OPTION_MULTILINE)) rb_str_buf_cat2(str, "m");
-	if (!(options & RE_OPTION_IGNORECASE)) rb_str_buf_cat2(str, "i");
-	if (!(options & RE_OPTION_EXTENDED)) rb_str_buf_cat2(str, "x");
+	if (!(options & ONIG_OPTION_MULTILINE)) rb_str_buf_cat2(str, "m");
+	if (!(options & ONIG_OPTION_IGNORECASE)) rb_str_buf_cat2(str, "i");
+	if (!(options & ONIG_OPTION_EXTEND)) rb_str_buf_cat2(str, "x");
     }
 
     rb_str_buf_cat2(str, ":");
@@ -547,7 +552,7 @@ rb_reg_casefold_p(re)
     VALUE re;
 {
     rb_reg_check(re);
-    if (RREGEXP(re)->ptr->options & RE_OPTION_IGNORECASE) return Qtrue;
+    if (RREGEXP(re)->ptr->options & ONIG_OPTION_IGNORECASE) return Qtrue;
     return Qfalse;
 }
 
@@ -626,6 +631,7 @@ make_regexp(s, len, flags, ce)
     Regexp *rp;
     char err[ONIG_MAX_ERROR_MESSAGE_LEN];
     int r;
+    OnigErrorInfo einfo;
 
     /* Handle escaped characters first. */
 
@@ -634,18 +640,19 @@ make_regexp(s, len, flags, ce)
        from that.
     */
 
-    r = re_alloc_pattern(&rp);
+    r = onig_alloc_init(&rp, flags,
+                        ONIGENC_AMBIGUOUS_MATCH_DEFAULT,
+                        onigenc_get_default_encoding(),
+                        OnigDefaultSyntax);
     if (r) {
-	re_error_code_to_str((UChar* )err, r);
+	onig_error_code_to_str((UChar* )err, r);
 	rb_reg_raise(s, len, err, 0, ce);
     }
 
-    if (flags) {
-	rp->options = flags;
-    }
-    r = re_compile_pattern(s, len, rp, err);
+    r = onig_compile(rp, (UChar* )s, (UChar* )(s + len), &einfo);
 
     if (r != 0) {
+	(void )onig_error_code_to_str((UChar* )err, r, &einfo);
 	rb_reg_raise(s, len, err, 0, ce);
     }
     return rp;
@@ -694,9 +701,9 @@ match_init_copy(obj, orig)
 	rb_raise(rb_eTypeError, "wrong argument class");
     }
     RMATCH(obj)->str = RMATCH(orig)->str;
-    re_free_registers(RMATCH(obj)->regs);
+    onig_region_free(RMATCH(obj)->regs, 0);
     RMATCH(obj)->regs->allocated = 0;
-    re_copy_registers(RMATCH(obj)->regs, RMATCH(orig)->regs);
+    onig_region_copy(RMATCH(obj)->regs, RMATCH(orig)->regs);
 
     return obj;
 }
@@ -830,12 +837,12 @@ rb_reg_prepare_re(re)
     /* ignorecase status */
     if (ruby_ignorecase && !state) {
 	FL_SET(re, REG_CASESTATE);
-	RREGEXP(re)->ptr->options |= RE_OPTION_IGNORECASE;
+	RREGEXP(re)->ptr->options |= ONIG_OPTION_IGNORECASE;
 	need_recompile = 1;
     }
     if (!ruby_ignorecase && state) {
 	FL_UNSET(re, REG_CASESTATE);
-	RREGEXP(re)->ptr->options &= ~RE_OPTION_IGNORECASE;
+	RREGEXP(re)->ptr->options &= ~ONIG_OPTION_IGNORECASE;
 	need_recompile = 1;
     }
 
@@ -849,13 +856,22 @@ rb_reg_prepare_re(re)
     if (need_recompile) {
 	char err[ONIG_MAX_ERROR_MESSAGE_LEN];
 	int r;
+	OnigErrorInfo einfo;
+	regex_t *reg;
+	UChar *pattern;
 
 	if (FL_TEST(re, KCODE_FIXED))
 	    kcode_set_option(re);
 	rb_reg_check(re);
-	r = re_recompile_pattern(RREGEXP(re)->str, RREGEXP(re)->len, RREGEXP(re)->ptr, err);
+	reg = RREGEXP(re)->ptr;
+	pattern = ((UChar* )RREGEXP(re)->str);
+	r = onig_recompile(reg, pattern, pattern + RREGEXP(re)->len,
+			   reg->options, onigenc_get_default_encoding(),
+			   OnigDefaultSyntax, &einfo);
+
 	if (r != 0) {
-	    rb_reg_raise(RREGEXP(re)->str, RREGEXP(re)->len, err, re, Qfalse);
+	     (void )onig_error_code_to_str((UChar* )err, r, &einfo);
+	     rb_reg_raise(pattern, RREGEXP(re)->len, err, re, Qfalse);
 	}
     }
 }
@@ -866,6 +882,8 @@ rb_reg_adjust_startpos(re, str, pos, reverse)
     long pos, reverse;
 {
     long range;
+    OnigEncoding enc;
+    UChar *p, *string;
 
     rb_reg_check(re);
     if (may_need_recompile) rb_reg_prepare_re(re);
@@ -881,9 +899,22 @@ rb_reg_adjust_startpos(re, str, pos, reverse)
     else {
 	range = RSTRING(str)->len - pos;
     }
-    return re_adjust_startpos(RREGEXP(re)->ptr,
-			      RSTRING(str)->ptr, RSTRING(str)->len,
-			      pos, range);
+
+    enc = (RREGEXP(re)->ptr)->enc;
+
+    if (pos > 0 && ONIGENC_MBC_MAXLEN(enc) != 1 && pos < RSTRING(str)->len) {
+	 string = (UChar* )RSTRING(str)->ptr;
+
+	 if (range > 0) {
+	      p = onigenc_get_right_adjust_char_head(enc, string, string + pos);
+	 }
+	 else {
+	      p = ONIGENC_LEFT_ADJUST_CHAR_HEAD(enc, string, string + pos);
+	 }
+	 return p - string;
+    }
+
+    return pos;
 }
 
 long
@@ -915,8 +946,13 @@ rb_reg_search(re, str, pos, reverse)
     else {
 	range = RSTRING(str)->len - pos;
     }
-    result = re_search(RREGEXP(re)->ptr,RSTRING(str)->ptr,RSTRING(str)->len,
-		       pos, range, &regs);
+
+    result = onig_search(RREGEXP(re)->ptr,
+			 (UChar* )(RSTRING(str)->ptr),
+			 ((UChar* )(RSTRING(str)->ptr) + RSTRING(str)->len),
+			 ((UChar* )(RSTRING(str)->ptr) + pos),
+			 ((UChar* )(RSTRING(str)->ptr) + pos + range),
+			 &regs, ONIG_OPTION_NONE);
 
     if (FL_TEST(re, KCODE_FIXED))
 	kcode_reset_option();
@@ -928,7 +964,7 @@ rb_reg_search(re, str, pos, reverse)
 	}
 	else {
 	    char err[ONIG_MAX_ERROR_MESSAGE_LEN];
-	    re_error_code_to_str((UChar* )err, result);
+	    onig_error_code_to_str((UChar* )err, result);
 	    rb_reg_raise(RREGEXP(re)->str, RREGEXP(re)->len, err, 0, Qfalse);
 	}
     }
@@ -944,7 +980,7 @@ rb_reg_search(re, str, pos, reverse)
 	    FL_UNSET(match, FL_TAINT);
     }
 
-    re_copy_registers(RMATCH(match)->regs, &regs);
+    onig_region_copy(RMATCH(match)->regs, &regs);
     RMATCH(match)->str = rb_str_new4(str);
     rb_backref_set(match);
 
@@ -1338,7 +1374,7 @@ rb_reg_initialize(obj, s, len, options, ce)
 {
     struct RRegexp *re = RREGEXP(obj);
 
-    if (re->ptr) re_free_pattern(re->ptr);
+    if (re->ptr) onig_free(re->ptr);
     if (re->str) free(re->str);
     re->ptr = 0;
     re->str = 0;
@@ -1366,7 +1402,7 @@ rb_reg_initialize(obj, s, len, options, ce)
 	kcode_set_option((VALUE)re);
     }
     if (ruby_ignorecase) {
-	options |= RE_OPTION_IGNORECASE;
+	options |= ONIG_OPTION_IGNORECASE;
 	FL_SET(re, REG_CASESTATE);
     }
     re->ptr = make_regexp(s, len, options & 0xf, ce);
@@ -1734,7 +1770,7 @@ rb_reg_initialize_m(argc, argv, self)
     else {
 	if (argc >= 2) {
 	    if (FIXNUM_P(argv[1])) flags = FIX2INT(argv[1]);
-	    else if (RTEST(argv[1])) flags = RE_OPTION_IGNORECASE;
+	    else if (RTEST(argv[1])) flags = ONIG_OPTION_IGNORECASE;
 	}
 	if (argc == 3 && !NIL_P(argv[2])) {
 	    char *kcode = StringValuePtr(argv[2]);
@@ -1924,7 +1960,7 @@ rb_reg_options(re)
 
     rb_reg_check(re);
     options = RREGEXP(re)->ptr->options &
-	(RE_OPTION_IGNORECASE|RE_OPTION_MULTILINE|RE_OPTION_EXTENDED);
+	(ONIG_OPTION_IGNORECASE|ONIG_OPTION_MULTILINE|ONIG_OPTION_EXTEND);
     if (FL_TEST(re, KCODE_FIXED)) {
 	options |= rb_reg_get_kcode(re);
     }
@@ -2157,17 +2193,17 @@ rb_set_kcode(code)
       case 'E':
       case 'e':
 	reg_kcode = KCODE_EUC;
-	re_mbcinit(MBCTYPE_EUC);
+	onigenc_set_default_encoding(ONIG_ENCODING_EUC_JP);
 	break;
       case 'S':
       case 's':
 	reg_kcode = KCODE_SJIS;
-	re_mbcinit(MBCTYPE_SJIS);
+	onigenc_set_default_encoding(ONIG_ENCODING_SJIS);
 	break;
       case 'U':
       case 'u':
 	reg_kcode = KCODE_UTF8;
-	re_mbcinit(MBCTYPE_UTF8);
+	onigenc_set_default_encoding(ONIG_ENCODING_UTF8);
 	break;
       default:
       case 'N':
@@ -2176,7 +2212,7 @@ rb_set_kcode(code)
       case 'a':
       set_no_conversion:
 	reg_kcode = KCODE_NONE;
-	re_mbcinit(MBCTYPE_ASCII);
+	onigenc_set_default_encoding(ONIG_ENCODING_ASCII);
 	break;
     }
 }
@@ -2271,17 +2307,17 @@ Init_Regexp()
 {
     rb_eRegexpError = rb_define_class("RegexpError", rb_eStandardError);
 
-    re_set_casetable(casetable);
+    onigenc_set_default_caseconv_table((UChar* )casetable);
 #if DEFAULT_KCODE == KCODE_EUC
-    re_mbcinit(MBCTYPE_EUC);
+    onigenc_set_default_encoding(ONIG_ENCODING_EUC_JP);
 #else
 #if DEFAULT_KCODE == KCODE_SJIS
-    re_mbcinit(MBCTYPE_SJIS);
+    onigenc_set_default_encoding(ONIG_ENCODING_SJIS);
 #else
 #if DEFAULT_KCODE == KCODE_UTF8
-    re_mbcinit(MBCTYPE_UTF8);
+    onigenc_set_default_encoding(ONIG_ENCODING_UTF8);
 #else
-    re_mbcinit(MBCTYPE_ASCII);
+    onigenc_set_default_encoding(ONIG_ENCODING_ASCII);
 #endif
 #endif
 #endif
@@ -2320,9 +2356,9 @@ Init_Regexp()
     rb_define_method(rb_cRegexp, "options", rb_reg_options_m, 0);
     rb_define_method(rb_cRegexp, "kcode", rb_reg_kcode_m, 0);
 
-    rb_define_const(rb_cRegexp, "IGNORECASE", INT2FIX(RE_OPTION_IGNORECASE));
-    rb_define_const(rb_cRegexp, "EXTENDED", INT2FIX(RE_OPTION_EXTENDED));
-    rb_define_const(rb_cRegexp, "MULTILINE", INT2FIX(RE_OPTION_MULTILINE));
+    rb_define_const(rb_cRegexp, "IGNORECASE", INT2FIX(ONIG_OPTION_IGNORECASE));
+    rb_define_const(rb_cRegexp, "EXTENDED", INT2FIX(ONIG_OPTION_EXTEND));
+    rb_define_const(rb_cRegexp, "MULTILINE", INT2FIX(ONIG_OPTION_MULTILINE));
 
     rb_global_variable(&reg_cache);
 
diff --git a/reggnu.c b/reggnu.c
deleted file mode 100644
index de7468f36a7893..00000000000000
--- a/reggnu.c
+++ /dev/null
@@ -1,276 +0,0 @@
-/**********************************************************************
-  reggnu.c -  Oniguruma (regular expression library)
-**********************************************************************/
-/*-
- * Copyright (c) 2002-2004  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 "regint.h"
-
-#ifndef ONIGGNU_H     /* name changes from oniggnu.h to regex.h in ruby. */
-#include "oniggnu.h"
-#endif
-
-#if defined(RUBY_PLATFORM) || defined(RUBY)
-#ifndef ONIG_RUBY_M17N
-#define USE_COMPATIBILITY_FOR_RUBY_EXTENSION_LIBRARY
-#endif
-#endif
-
-extern void
-re_free_registers(OnigRegion* r)
-{
-  /* 0: don't free self */
-  onig_region_free(r, 0);
-}
-
-extern int
-re_adjust_startpos(regex_t* reg, const char* string, int size,
-		   int startpos, int range)
-{
-  if (startpos > 0 && ONIGENC_MBC_MAXLEN(reg->enc) != 1 && startpos < size) {
-    UChar *p;
-    UChar *s = (UChar* )string + startpos;
-
-    if (range > 0) {
-      p = onigenc_get_right_adjust_char_head(reg->enc, (UChar* )string, s);
-    }
-    else {
-      p = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc, (UChar* )string, s);
-    }
-    return p - (UChar* )string;
-  }
-
-  return startpos;
-}
-
-extern int
-re_match(regex_t* reg, const char* str, int size, int pos,
-	 struct re_registers* regs)
-{
-  return onig_match(reg, (UChar* )str, (UChar* )(str + size),
-		    (UChar* )(str + pos), regs, ONIG_OPTION_NONE);
-}
-
-extern int
-re_search(regex_t* bufp, const char* string, int size, int startpos, int range,
-	  struct re_registers* regs)
-{
-  return onig_search(bufp, (UChar* )string, (UChar* )(string + size),
-		     (UChar* )(string + startpos),
-		     (UChar* )(string + startpos + range),
-		     regs, ONIG_OPTION_NONE);
-}
-
-extern int
-re_compile_pattern(const char* pattern, int size, regex_t* reg, char* ebuf)
-{
-  int r;
-  OnigErrorInfo einfo;
-
-  r = onig_compile(reg, (UChar* )pattern, (UChar* )(pattern + size), &einfo);
-  if (r != 0) {
-    if (IS_NOT_NULL(ebuf))
-      (void )onig_error_code_to_str((UChar* )ebuf, r, &einfo);
-  }
-
-  return r;
-}
-
-extern int
-re_recompile_pattern(const char* pattern, int size, regex_t* reg, char* ebuf)
-{
-  int r;
-  OnigErrorInfo einfo;
-  OnigEncoding enc;
-
-  /* I think encoding and options should be arguments of this function.
-     But this is adapted to present re.c. (2002/11/29)
-   */
-  enc = OnigEncDefaultCharEncoding;
-
-  r = onig_recompile(reg, (UChar* )pattern, (UChar* )(pattern + size),
-		     reg->options, enc, OnigDefaultSyntax, &einfo);
-  if (r != 0) {
-    if (IS_NOT_NULL(ebuf))
-      (void )onig_error_code_to_str((UChar* )ebuf, r, &einfo);
-  }
-  return r;
-}
-
-extern void
-re_free_pattern(regex_t* reg)
-{
-  onig_free(reg);
-}
-
-extern int
-re_alloc_pattern(regex_t** reg)
-{
-  return onig_alloc_init(reg, ONIG_OPTION_DEFAULT,
-                         ONIGENC_AMBIGUOUS_MATCH_DEFAULT,
-                         OnigEncDefaultCharEncoding,
-			 OnigDefaultSyntax);
-}
-
-extern void
-re_set_casetable(const char* table)
-{
-  onigenc_set_default_caseconv_table((UChar* )table);
-}
-
-#ifdef USE_COMPATIBILITY_FOR_RUBY_EXTENSION_LIBRARY
-static const unsigned char mbctab_ascii[] = {
-  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,
-};
-
-static const unsigned char mbctab_euc[] = {
-  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, 1, 2,
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
-};
-
-static const unsigned char mbctab_sjis[] = {
-  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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  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,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0
-};
-
-static const unsigned char mbctab_utf8[] = {
-  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,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-  3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 0, 0,
-};
-
-const unsigned char *re_mbctab = mbctab_ascii;
-#endif
-
-extern void
-#ifdef ONIG_RUBY_M17N
-re_mbcinit(OnigEncoding enc)
-#else
-re_mbcinit(int mb_code)
-#endif
-{
-#ifdef ONIG_RUBY_M17N
-
-  onigenc_set_default_encoding(enc);
-
-#else
-
-  OnigEncoding enc;
-
-  switch (mb_code) {
-  case MBCTYPE_ASCII:
-    enc = ONIG_ENCODING_ASCII;
-    break;
-  case MBCTYPE_EUC:
-    enc = ONIG_ENCODING_EUC_JP;
-    break;
-  case MBCTYPE_SJIS:
-    enc = ONIG_ENCODING_SJIS;
-    break;
-  case MBCTYPE_UTF8:
-    enc = ONIG_ENCODING_UTF8;
-    break;
-  default:
-    return ;
-    break;
-  }
-
-  onigenc_set_default_encoding(enc);
-#endif
-
-#ifdef USE_COMPATIBILITY_FOR_RUBY_EXTENSION_LIBRARY
-  switch (mb_code) {
-  case MBCTYPE_ASCII:
-    re_mbctab = mbctab_ascii;
-    break;
-  case MBCTYPE_EUC:
-    re_mbctab = mbctab_euc;
-    break;
-  case MBCTYPE_SJIS:
-    re_mbctab = mbctab_sjis;
-    break;
-  case MBCTYPE_UTF8:
-    re_mbctab = mbctab_utf8;
-    break;
-  }
-#endif
-}