Fresh start

1 files changed, 1950 insertions, 0 deletions

diff --git a/jni/ruby/encoding.c b/jni/ruby/encoding.c
new file mode 100644
index 0000000..b89832e
--- /dev/null
+++ b/jni/ruby/encoding.c
@@ -0,0 +1,1950 @@
+/**********************************************************************
+
+  encoding.c -
+
+  $Author: nobu $
+  created at: Thu May 24 17:23:27 JST 2007
+
+  Copyright (C) 2007 Yukihiro Matsumoto
+
+**********************************************************************/
+
+#include "internal.h"
+#include "regenc.h"
+#include <ctype.h>
+#include "ruby/util.h"
+
+#undef rb_ascii8bit_encindex
+#undef rb_utf8_encindex
+#undef rb_usascii_encindex
+
+typedef OnigEncodingType rb_raw_encoding;
+
+#if defined __GNUC__ && __GNUC__ >= 4
+#pragma GCC visibility push(default)
+int rb_enc_register(const char *name, rb_encoding *encoding);
+void rb_enc_set_base(const char *name, const char *orig);
+int rb_enc_set_dummy(int index);
+void rb_encdb_declare(const char *name);
+int rb_encdb_replicate(const char *name, const char *orig);
+int rb_encdb_dummy(const char *name);
+int rb_encdb_alias(const char *alias, const char *orig);
+void rb_encdb_set_unicode(int index);
+#pragma GCC visibility pop
+#endif
+
+static ID id_encoding;
+VALUE rb_cEncoding;
+static VALUE rb_encoding_list;
+
+struct rb_encoding_entry {
+    const char *name;
+    rb_encoding *enc;
+    rb_encoding *base;
+};
+
+static struct {
+    struct rb_encoding_entry *list;
+    int count;
+    int size;
+    st_table *names;
+} enc_table;
+
+#define ENC_DUMMY_FLAG (1<<24)
+#define ENC_INDEX_MASK (~(~0U<<24))
+
+#define ENC_TO_ENCINDEX(enc) (int)((enc)->ruby_encoding_index & ENC_INDEX_MASK)
+#define ENC_DUMMY_P(enc) ((enc)->ruby_encoding_index & ENC_DUMMY_FLAG)
+#define ENC_SET_DUMMY(enc) ((enc)->ruby_encoding_index |= ENC_DUMMY_FLAG)
+
+void rb_enc_init(void);
+
+#define ENCODING_COUNT ENCINDEX_BUILTIN_MAX
+#define UNSPECIFIED_ENCODING INT_MAX
+
+#define ENCODING_NAMELEN_MAX 63
+#define valid_encoding_name_p(name) ((name) && strlen(name) <= ENCODING_NAMELEN_MAX)
+
+#define enc_autoload_p(enc) (!rb_enc_mbmaxlen(enc))
+
+static int load_encoding(const char *name);
+
+static const rb_data_type_t encoding_data_type = {
+    "encoding",
+    {0, 0, 0,},
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY
+};
+
+#define is_data_encoding(obj) (RTYPEDDATA_P(obj) && RTYPEDDATA_TYPE(obj) == &encoding_data_type)
+#define is_obj_encoding(obj) (RB_TYPE_P((obj), T_DATA) && is_data_encoding(obj))
+
+static VALUE
+enc_new(rb_encoding *encoding)
+{
+    return TypedData_Wrap_Struct(rb_cEncoding, &encoding_data_type, (void *)encoding);
+}
+
+static VALUE
+rb_enc_from_encoding_index(int idx)
+{
+    VALUE list, enc;
+
+    if (!(list = rb_encoding_list)) {
+	rb_bug("rb_enc_from_encoding_index(%d): no rb_encoding_list", idx);
+    }
+    enc = rb_ary_entry(list, idx);
+    if (NIL_P(enc)) {
+	rb_bug("rb_enc_from_encoding_index(%d): not created yet", idx);
+    }
+    return enc;
+}
+
+VALUE
+rb_enc_from_encoding(rb_encoding *encoding)
+{
+    int idx;
+    if (!encoding) return Qnil;
+    idx = ENC_TO_ENCINDEX(encoding);
+    return rb_enc_from_encoding_index(idx);
+}
+
+int
+rb_enc_to_index(rb_encoding *enc)
+{
+    return enc ? ENC_TO_ENCINDEX(enc) : 0;
+}
+
+int
+rb_enc_dummy_p(rb_encoding *enc)
+{
+    return ENC_DUMMY_P(enc) != 0;
+}
+
+static int enc_autoload(rb_encoding *);
+
+static int
+check_encoding(rb_encoding *enc)
+{
+    int index = rb_enc_to_index(enc);
+    if (rb_enc_from_index(index) != enc)
+	return -1;
+    if (enc_autoload_p(enc)) {
+	index = enc_autoload(enc);
+    }
+    return index;
+}
+
+static int
+enc_check_encoding(VALUE obj)
+{
+    if (!is_obj_encoding(obj)) {
+	return -1;
+    }
+    return check_encoding(RDATA(obj)->data);
+}
+
+NORETURN(static void not_encoding(VALUE enc));
+static void
+not_encoding(VALUE enc)
+{
+    rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (expected Encoding)",
+	     rb_obj_class(enc));
+}
+
+static rb_encoding *
+must_encoding(VALUE enc)
+{
+    int index = enc_check_encoding(enc);
+    if (index < 0) {
+	not_encoding(enc);
+    }
+    return DATA_PTR(enc);
+}
+
+static rb_encoding *
+must_encindex(int index)
+{
+    rb_encoding *enc = rb_enc_from_index(index);
+    if (!enc) {
+	rb_raise(rb_eEncodingError, "encoding index out of bound: %d",
+		 index);
+    }
+    if (ENC_TO_ENCINDEX(enc) != (int)(index & ENC_INDEX_MASK)) {
+	rb_raise(rb_eEncodingError, "wrong encoding index %d for %s (expected %d)",
+		 index, rb_enc_name(enc), ENC_TO_ENCINDEX(enc));
+    }
+    if (enc_autoload_p(enc) && enc_autoload(enc) == -1) {
+	rb_loaderror("failed to load encoding (%s)",
+		     rb_enc_name(enc));
+    }
+    return enc;
+}
+
+int
+rb_to_encoding_index(VALUE enc)
+{
+    int idx;
+
+    idx = enc_check_encoding(enc);
+    if (idx >= 0) {
+	return idx;
+    }
+    else if (NIL_P(enc = rb_check_string_type(enc))) {
+	return -1;
+    }
+    if (!rb_enc_asciicompat(rb_enc_get(enc))) {
+	return -1;
+    }
+    return rb_enc_find_index(StringValueCStr(enc));
+}
+
+/* Returns encoding index or UNSPECIFIED_ENCODING */
+static int
+str_find_encindex(VALUE enc)
+{
+    int idx;
+
+    StringValue(enc);
+    if (!rb_enc_asciicompat(rb_enc_get(enc))) {
+	rb_raise(rb_eArgError, "invalid name encoding (non ASCII)");
+    }
+    idx = rb_enc_find_index(StringValueCStr(enc));
+    return idx;
+}
+
+static int
+str_to_encindex(VALUE enc)
+{
+    int idx = str_find_encindex(enc);
+    if (idx < 0) {
+	rb_raise(rb_eArgError, "unknown encoding name - %"PRIsVALUE, enc);
+    }
+    return idx;
+}
+
+static rb_encoding *
+str_to_encoding(VALUE enc)
+{
+    return rb_enc_from_index(str_to_encindex(enc));
+}
+
+rb_encoding *
+rb_to_encoding(VALUE enc)
+{
+    if (enc_check_encoding(enc) >= 0) return RDATA(enc)->data;
+    return str_to_encoding(enc);
+}
+
+rb_encoding *
+rb_find_encoding(VALUE enc)
+{
+    int idx;
+    if (enc_check_encoding(enc) >= 0) return RDATA(enc)->data;
+    idx = str_find_encindex(enc);
+    if (idx < 0) return NULL;
+    return rb_enc_from_index(idx);
+}
+
+void
+rb_gc_mark_encodings(void)
+{
+}
+
+static int
+enc_table_expand(int newsize)
+{
+    struct rb_encoding_entry *ent;
+    int count = newsize;
+
+    if (enc_table.size >= newsize) return newsize;
+    newsize = (newsize + 7) / 8 * 8;
+    ent = realloc(enc_table.list, sizeof(*enc_table.list) * newsize);
+    if (!ent) return -1;
+    memset(ent + enc_table.size, 0, sizeof(*ent)*(newsize - enc_table.size));
+    enc_table.list = ent;
+    enc_table.size = newsize;
+    return count;
+}
+
+static int
+enc_register_at(int index, const char *name, rb_encoding *base_encoding)
+{
+    struct rb_encoding_entry *ent = &enc_table.list[index];
+    rb_raw_encoding *encoding;
+    VALUE list;
+
+    if (!valid_encoding_name_p(name)) return -1;
+    if (!ent->name) {
+	ent->name = name = strdup(name);
+    }
+    else if (STRCASECMP(name, ent->name)) {
+	return -1;
+    }
+    encoding = (rb_raw_encoding *)ent->enc;
+    if (!encoding) {
+	encoding = xmalloc(sizeof(rb_encoding));
+    }
+    if (base_encoding) {
+	*encoding = *base_encoding;
+    }
+    else {
+	memset(encoding, 0, sizeof(*ent->enc));
+    }
+    encoding->name = name;
+    encoding->ruby_encoding_index = index;
+    ent->enc = encoding;
+    st_insert(enc_table.names, (st_data_t)name, (st_data_t)index);
+    list = rb_encoding_list;
+    if (list && NIL_P(rb_ary_entry(list, index))) {
+	/* initialize encoding data */
+	rb_ary_store(list, index, enc_new(encoding));
+    }
+    return index;
+}
+
+static int
+enc_register(const char *name, rb_encoding *encoding)
+{
+    int index = enc_table.count;
+
+    if ((index = enc_table_expand(index + 1)) < 0) return -1;
+    enc_table.count = index;
+    return enc_register_at(index - 1, name, encoding);
+}
+
+static void set_encoding_const(const char *, rb_encoding *);
+int rb_enc_registered(const char *name);
+
+int
+rb_enc_register(const char *name, rb_encoding *encoding)
+{
+    int index = rb_enc_registered(name);
+
+    if (index >= 0) {
+	rb_encoding *oldenc = rb_enc_from_index(index);
+	if (STRCASECMP(name, rb_enc_name(oldenc))) {
+	    index = enc_register(name, encoding);
+	}
+	else if (enc_autoload_p(oldenc) || !ENC_DUMMY_P(oldenc)) {
+	    enc_register_at(index, name, encoding);
+	}
+	else {
+	    rb_raise(rb_eArgError, "encoding %s is already registered", name);
+	}
+    }
+    else {
+	index = enc_register(name, encoding);
+	set_encoding_const(name, rb_enc_from_index(index));
+    }
+    return index;
+}
+
+void
+rb_encdb_declare(const char *name)
+{
+    int idx = rb_enc_registered(name);
+    if (idx < 0) {
+	idx = enc_register(name, 0);
+    }
+    set_encoding_const(name, rb_enc_from_index(idx));
+}
+
+static void
+enc_check_duplication(const char *name)
+{
+    if (rb_enc_registered(name) >= 0) {
+	rb_raise(rb_eArgError, "encoding %s is already registered", name);
+    }
+}
+
+static rb_encoding*
+set_base_encoding(int index, rb_encoding *base)
+{
+    rb_encoding *enc = enc_table.list[index].enc;
+
+    enc_table.list[index].base = base;
+    if (ENC_DUMMY_P(base)) ENC_SET_DUMMY((rb_raw_encoding *)enc);
+    return enc;
+}
+
+/* for encdb.h
+ * Set base encoding for encodings which are not replicas
+ * but not in their own files.
+ */
+void
+rb_enc_set_base(const char *name, const char *orig)
+{
+    int idx = rb_enc_registered(name);
+    int origidx = rb_enc_registered(orig);
+    set_base_encoding(idx, rb_enc_from_index(origidx));
+}
+
+/* for encdb.h
+ * Set encoding dummy.
+ */
+int
+rb_enc_set_dummy(int index)
+{
+    rb_encoding *enc = enc_table.list[index].enc;
+
+    ENC_SET_DUMMY((rb_raw_encoding *)enc);
+    return index;
+}
+
+int
+rb_enc_replicate(const char *name, rb_encoding *encoding)
+{
+    int idx;
+
+    enc_check_duplication(name);
+    idx = enc_register(name, encoding);
+    set_base_encoding(idx, encoding);
+    set_encoding_const(name, rb_enc_from_index(idx));
+    return idx;
+}
+
+/*
+ * call-seq:
+ *   enc.replicate(name) -> encoding
+ *
+ * Returns a replicated encoding of _enc_ whose name is _name_.
+ * The new encoding should have the same byte structure of _enc_.
+ * If _name_ is used by another encoding, raise ArgumentError.
+ *
+ */
+static VALUE
+enc_replicate(VALUE encoding, VALUE name)
+{
+    return rb_enc_from_encoding_index(
+	rb_enc_replicate(StringValueCStr(name),
+			 rb_to_encoding(encoding)));
+}
+
+static int
+enc_replicate_with_index(const char *name, rb_encoding *origenc, int idx)
+{
+    if (idx < 0) {
+	idx = enc_register(name, origenc);
+    }
+    else {
+	idx = enc_register_at(idx, name, origenc);
+    }
+    if (idx >= 0) {
+	set_base_encoding(idx, origenc);
+	set_encoding_const(name, rb_enc_from_index(idx));
+    }
+    return idx;
+}
+
+int
+rb_encdb_replicate(const char *name, const char *orig)
+{
+    int origidx = rb_enc_registered(orig);
+    int idx = rb_enc_registered(name);
+
+    if (origidx < 0) {
+	origidx = enc_register(orig, 0);
+    }
+    return enc_replicate_with_index(name, rb_enc_from_index(origidx), idx);
+}
+
+int
+rb_define_dummy_encoding(const char *name)
+{
+    int index = rb_enc_replicate(name, rb_ascii8bit_encoding());
+    rb_encoding *enc = enc_table.list[index].enc;
+
+    ENC_SET_DUMMY((rb_raw_encoding *)enc);
+    return index;
+}
+
+int
+rb_encdb_dummy(const char *name)
+{
+    int index = enc_replicate_with_index(name, rb_ascii8bit_encoding(),
+					 rb_enc_registered(name));
+    rb_encoding *enc = enc_table.list[index].enc;
+
+    ENC_SET_DUMMY((rb_raw_encoding *)enc);
+    return index;
+}
+
+/*
+ * call-seq:
+ *   enc.dummy? -> true or false
+ *
+ * Returns true for dummy encodings.
+ * A dummy encoding is an encoding for which character handling is not properly
+ * implemented.
+ * It is used for stateful encodings.
+ *
+ *   Encoding::ISO_2022_JP.dummy?       #=> true
+ *   Encoding::UTF_8.dummy?             #=> false
+ *
+ */
+static VALUE
+enc_dummy_p(VALUE enc)
+{
+    return ENC_DUMMY_P(must_encoding(enc)) ? Qtrue : Qfalse;
+}
+
+/*
+ * call-seq:
+ *   enc.ascii_compatible? -> true or false
+ *
+ * Returns whether ASCII-compatible or not.
+ *
+ *   Encoding::UTF_8.ascii_compatible?     #=> true
+ *   Encoding::UTF_16BE.ascii_compatible?  #=> false
+ *
+ */
+static VALUE
+enc_ascii_compatible_p(VALUE enc)
+{
+    return rb_enc_asciicompat(must_encoding(enc)) ? Qtrue : Qfalse;
+}
+
+/*
+ * Returns 1 when the encoding is Unicode series other than UTF-7 else 0.
+ */
+int
+rb_enc_unicode_p(rb_encoding *enc)
+{
+    return ONIGENC_IS_UNICODE(enc);
+}
+
+static st_data_t
+enc_dup_name(st_data_t name)
+{
+    return (st_data_t)strdup((const char *)name);
+}
+
+/*
+ * Returns copied alias name when the key is added for st_table,
+ * else returns NULL.
+ */
+static int
+enc_alias_internal(const char *alias, int idx)
+{
+    return st_insert2(enc_table.names, (st_data_t)alias, (st_data_t)idx,
+		      enc_dup_name);
+}
+
+static int
+enc_alias(const char *alias, int idx)
+{
+    if (!valid_encoding_name_p(alias)) return -1;
+    if (!enc_alias_internal(alias, idx))
+	set_encoding_const(alias, rb_enc_from_index(idx));
+    return idx;
+}
+
+int
+rb_enc_alias(const char *alias, const char *orig)
+{
+    int idx;
+
+    enc_check_duplication(alias);
+    if (!enc_table.list) {
+	rb_enc_init();
+    }
+    if ((idx = rb_enc_find_index(orig)) < 0) {
+	return -1;
+    }
+    return enc_alias(alias, idx);
+}
+
+int
+rb_encdb_alias(const char *alias, const char *orig)
+{
+    int idx = rb_enc_registered(orig);
+
+    if (idx < 0) {
+	idx = enc_register(orig, 0);
+    }
+    return enc_alias(alias, idx);
+}
+
+void
+rb_encdb_set_unicode(int index)
+{
+    ((rb_raw_encoding *)rb_enc_from_index(index))->flags |= ONIGENC_FLAG_UNICODE;
+}
+
+void
+rb_enc_init(void)
+{
+    enc_table_expand(ENCODING_COUNT + 1);
+    if (!enc_table.names) {
+	enc_table.names = st_init_strcasetable();
+    }
+#define ENC_REGISTER(enc) enc_register_at(ENCINDEX_##enc, rb_enc_name(&OnigEncoding##enc), &OnigEncoding##enc)
+    ENC_REGISTER(ASCII);
+    ENC_REGISTER(UTF_8);
+    ENC_REGISTER(US_ASCII);
+#undef ENC_REGISTER
+#define ENCDB_REGISTER(name, enc) enc_register_at(ENCINDEX_##enc, name, NULL)
+    ENCDB_REGISTER("UTF-16BE", UTF_16BE);
+    ENCDB_REGISTER("UTF-16LE", UTF_16LE);
+    ENCDB_REGISTER("UTF-32BE", UTF_32BE);
+    ENCDB_REGISTER("UTF-32LE", UTF_32LE);
+    ENCDB_REGISTER("UTF-16", UTF_16);
+    ENCDB_REGISTER("UTF-32", UTF_32);
+    ENCDB_REGISTER("UTF8-MAC", UTF8_MAC);
+
+    ENCDB_REGISTER("EUC-JP", EUC_JP);
+    ENCDB_REGISTER("Windows-31J", Windows_31J);
+#undef ENCDB_REGISTER
+    enc_table.count = ENCINDEX_BUILTIN_MAX;
+}
+
+rb_encoding *
+rb_enc_from_index(int index)
+{
+    if (!enc_table.list) {
+	rb_enc_init();
+    }
+    if (index < 0 || enc_table.count <= (index &= ENC_INDEX_MASK)) {
+	return 0;
+    }
+    return enc_table.list[index].enc;
+}
+
+rb_encoding *
+rb_enc_get_from_index(int index)
+{
+    return must_encindex(index);
+}
+
+int
+rb_enc_registered(const char *name)
+{
+    st_data_t idx = 0;
+
+    if (!name) return -1;
+    if (!enc_table.list) return -1;
+    if (st_lookup(enc_table.names, (st_data_t)name, &idx)) {
+	return (int)idx;
+    }
+    return -1;
+}
+
+static int
+load_encoding(const char *name)
+{
+    VALUE enclib = rb_sprintf("enc/%s.so", name);
+    VALUE verbose = ruby_verbose;
+    VALUE debug = ruby_debug;
+    VALUE errinfo;
+    char *s = RSTRING_PTR(enclib) + 4, *e = RSTRING_END(enclib) - 3;
+    int loaded;
+    int idx;
+
+    while (s < e) {
+	if (!ISALNUM(*s)) *s = '_';
+	else if (ISUPPER(*s)) *s = (char)TOLOWER(*s);
+	++s;
+    }
+    FL_UNSET(enclib, FL_TAINT);
+    OBJ_FREEZE(enclib);
+    ruby_verbose = Qfalse;
+    ruby_debug = Qfalse;
+    errinfo = rb_errinfo();
+    loaded = rb_require_internal(enclib, rb_safe_level());
+    ruby_verbose = verbose;
+    ruby_debug = debug;
+    rb_set_errinfo(errinfo);
+    if (loaded < 0 || 1 < loaded) return -1;
+    if ((idx = rb_enc_registered(name)) < 0) return -1;
+    if (enc_autoload_p(enc_table.list[idx].enc)) return -1;
+    return idx;
+}
+
+static int
+enc_autoload(rb_encoding *enc)
+{
+    int i;
+    rb_encoding *base = enc_table.list[ENC_TO_ENCINDEX(enc)].base;
+
+    if (base) {
+	i = 0;
+	do {
+	    if (i >= enc_table.count) return -1;
+	} while (enc_table.list[i].enc != base && (++i, 1));
+	if (enc_autoload_p(base)) {
+	    if (enc_autoload(base) < 0) return -1;
+	}
+	i = enc->ruby_encoding_index;
+	enc_register_at(i & ENC_INDEX_MASK, rb_enc_name(enc), base);
+	((rb_raw_encoding *)enc)->ruby_encoding_index = i;
+    }
+    else {
+	i = load_encoding(rb_enc_name(enc));
+    }
+    return i;
+}
+
+/* Return encoding index or UNSPECIFIED_ENCODING from encoding name */
+int
+rb_enc_find_index(const char *name)
+{
+    int i = rb_enc_registered(name);
+    rb_encoding *enc;
+
+    if (i < 0) {
+	i = load_encoding(name);
+    }
+    else if (!(enc = rb_enc_from_index(i))) {
+	if (i != UNSPECIFIED_ENCODING) {
+	    rb_raise(rb_eArgError, "encoding %s is not registered", name);
+	}
+    }
+    else if (enc_autoload_p(enc)) {
+	if (enc_autoload(enc) < 0) {
+	    rb_warn("failed to load encoding (%s); use ASCII-8BIT instead",
+		    name);
+	    return 0;
+	}
+    }
+    return i;
+}
+
+rb_encoding *
+rb_enc_find(const char *name)
+{
+    int idx = rb_enc_find_index(name);
+    if (idx < 0) idx = 0;
+    return rb_enc_from_index(idx);
+}
+
+static inline int
+enc_capable(VALUE obj)
+{
+    if (SPECIAL_CONST_P(obj)) return SYMBOL_P(obj);
+    switch (BUILTIN_TYPE(obj)) {
+      case T_STRING:
+      case T_REGEXP:
+      case T_FILE:
+      case T_SYMBOL:
+	return TRUE;
+      case T_DATA:
+	if (is_data_encoding(obj)) return TRUE;
+      default:
+	return FALSE;
+    }
+}
+
+ID
+rb_id_encoding(void)
+{
+    CONST_ID(id_encoding, "encoding");
+    return id_encoding;
+}
+
+int
+rb_enc_get_index(VALUE obj)
+{
+    int i = -1;
+    VALUE tmp;
+
+    if (SPECIAL_CONST_P(obj)) {
+	if (!SYMBOL_P(obj)) return -1;
+	obj = rb_sym2str(obj);
+    }
+    switch (BUILTIN_TYPE(obj)) {
+      as_default:
+      default:
+      case T_STRING:
+      case T_REGEXP:
+	i = ENCODING_GET_INLINED(obj);
+	if (i == ENCODING_INLINE_MAX) {
+	    VALUE iv;
+
+	    iv = rb_ivar_get(obj, rb_id_encoding());
+	    i = NUM2INT(iv);
+	}
+	break;
+      case T_FILE:
+	tmp = rb_funcall(obj, rb_intern("internal_encoding"), 0, 0);
+	if (NIL_P(tmp)) obj = rb_funcall(obj, rb_intern("external_encoding"), 0, 0);
+	else obj = tmp;
+	if (NIL_P(obj)) break;
+      case T_DATA:
+	if (is_data_encoding(obj)) {
+	    i = enc_check_encoding(obj);
+	}
+	else {
+	    goto as_default;
+	}
+	break;
+    }
+    return i;
+}
+
+static void
+enc_set_index(VALUE obj, int idx)
+{
+    if (idx < ENCODING_INLINE_MAX) {
+	ENCODING_SET_INLINED(obj, idx);
+	return;
+    }
+    ENCODING_SET_INLINED(obj, ENCODING_INLINE_MAX);
+    rb_ivar_set(obj, rb_id_encoding(), INT2NUM(idx));
+}
+
+void
+rb_enc_set_index(VALUE obj, int idx)
+{
+    rb_check_frozen(obj);
+    must_encindex(idx);
+    enc_set_index(obj, idx);
+}
+
+VALUE
+rb_enc_associate_index(VALUE obj, int idx)
+{
+    rb_encoding *enc;
+    int oldidx, oldtermlen, termlen;
+
+/*    enc_check_capable(obj);*/
+    rb_check_frozen(obj);
+    oldidx = rb_enc_get_index(obj);
+    if (oldidx == idx)
+	return obj;
+    if (SPECIAL_CONST_P(obj)) {
+	rb_raise(rb_eArgError, "cannot set encoding");
+    }
+    enc = must_encindex(idx);
+    if (!ENC_CODERANGE_ASCIIONLY(obj) ||
+	!rb_enc_asciicompat(enc)) {
+	ENC_CODERANGE_CLEAR(obj);
+    }
+    termlen = rb_enc_mbminlen(enc);
+    oldtermlen = rb_enc_mbminlen(rb_enc_from_index(oldidx));
+    if (oldtermlen < termlen && RB_TYPE_P(obj, T_STRING)) {
+	rb_str_fill_terminator(obj, termlen);
+    }
+    enc_set_index(obj, idx);
+    return obj;
+}
+
+VALUE
+rb_enc_associate(VALUE obj, rb_encoding *enc)
+{
+    return rb_enc_associate_index(obj, rb_enc_to_index(enc));
+}
+
+rb_encoding*
+rb_enc_get(VALUE obj)
+{
+    return rb_enc_from_index(rb_enc_get_index(obj));
+}
+
+rb_encoding*
+rb_enc_check(VALUE str1, VALUE str2)
+{
+    rb_encoding *enc = rb_enc_compatible(str1, str2);
+    if (!enc)
+	rb_raise(rb_eEncCompatError, "incompatible character encodings: %s and %s",
+		 rb_enc_name(rb_enc_get(str1)),
+		 rb_enc_name(rb_enc_get(str2)));
+    return enc;
+}
+
+rb_encoding*
+rb_enc_compatible(VALUE str1, VALUE str2)
+{
+    int idx1, idx2;
+    rb_encoding *enc1, *enc2;
+    int isstr1, isstr2;
+
+    idx1 = rb_enc_get_index(str1);
+    idx2 = rb_enc_get_index(str2);
+
+    if (idx1 < 0 || idx2 < 0)
+        return 0;
+
+    if (idx1 == idx2) {
+	return rb_enc_from_index(idx1);
+    }
+    enc1 = rb_enc_from_index(idx1);
+    enc2 = rb_enc_from_index(idx2);
+
+    isstr2 = RB_TYPE_P(str2, T_STRING);
+    if (isstr2 && RSTRING_LEN(str2) == 0)
+	return enc1;
+    isstr1 = RB_TYPE_P(str1, T_STRING);
+    if (isstr1 && RSTRING_LEN(str1) == 0)
+	return (rb_enc_asciicompat(enc1) && rb_enc_str_asciionly_p(str2)) ? enc1 : enc2;
+    if (!rb_enc_asciicompat(enc1) || !rb_enc_asciicompat(enc2)) {
+	return 0;
+    }
+
+    /* objects whose encoding is the same of contents */
+    if (!isstr2 && idx2 == ENCINDEX_US_ASCII)
+	return enc1;
+    if (!isstr1 && idx1 == ENCINDEX_US_ASCII)
+	return enc2;
+
+    if (!isstr1) {
+	VALUE tmp = str1;
+	int idx0 = idx1;
+	str1 = str2;
+	str2 = tmp;
+	idx1 = idx2;
+	idx2 = idx0;
+	idx0 = isstr1;
+	isstr1 = isstr2;
+	isstr2 = idx0;
+    }
+    if (isstr1) {
+	int cr1, cr2;
+
+	cr1 = rb_enc_str_coderange(str1);
+	if (isstr2) {
+	    cr2 = rb_enc_str_coderange(str2);
+	    if (cr1 != cr2) {
+		/* may need to handle ENC_CODERANGE_BROKEN */
+		if (cr1 == ENC_CODERANGE_7BIT) return enc2;
+		if (cr2 == ENC_CODERANGE_7BIT) return enc1;
+	    }
+	    if (cr2 == ENC_CODERANGE_7BIT) {
+		return enc1;
+	    }
+	}
+	if (cr1 == ENC_CODERANGE_7BIT)
+	    return enc2;
+    }
+    return 0;
+}
+
+void
+rb_enc_copy(VALUE obj1, VALUE obj2)
+{
+    rb_enc_associate_index(obj1, rb_enc_get_index(obj2));
+}
+
+
+/*
+ *  call-seq:
+ *     obj.encoding   -> encoding
+ *
+ *  Returns the Encoding object that represents the encoding of obj.
+ */
+
+VALUE
+rb_obj_encoding(VALUE obj)
+{
+    int idx = rb_enc_get_index(obj);
+    if (idx < 0) {
+	rb_raise(rb_eTypeError, "unknown encoding");
+    }
+    return rb_enc_from_encoding_index(idx & ENC_INDEX_MASK);
+}
+
+int
+rb_enc_fast_mbclen(const char *p, const char *e, rb_encoding *enc)
+{
+    return ONIGENC_MBC_ENC_LEN(enc, (UChar*)p, (UChar*)e);
+}
+
+int
+rb_enc_mbclen(const char *p, const char *e, rb_encoding *enc)
+{
+    int n = ONIGENC_PRECISE_MBC_ENC_LEN(enc, (UChar*)p, (UChar*)e);
+    if (MBCLEN_CHARFOUND_P(n) && MBCLEN_CHARFOUND_LEN(n) <= e-p)
+        return MBCLEN_CHARFOUND_LEN(n);
+    else {
+        int min = rb_enc_mbminlen(enc);
+        return min <= e-p ? min : (int)(e-p);
+    }
+}
+
+int
+rb_enc_precise_mbclen(const char *p, const char *e, rb_encoding *enc)
+{
+    int n;
+    if (e <= p)
+        return ONIGENC_CONSTRUCT_MBCLEN_NEEDMORE(1);
+    n = ONIGENC_PRECISE_MBC_ENC_LEN(enc, (UChar*)p, (UChar*)e);
+    if (e-p < n)
+        return ONIGENC_CONSTRUCT_MBCLEN_NEEDMORE(n-(int)(e-p));
+    return n;
+}
+
+int
+rb_enc_ascget(const char *p, const char *e, int *len, rb_encoding *enc)
+{
+    unsigned int c, l;
+    if (e <= p)
+        return -1;
+    if (rb_enc_asciicompat(enc)) {
+        c = (unsigned char)*p;
+        if (!ISASCII(c))
+            return -1;
+        if (len) *len = 1;
+        return c;
+    }
+    l = rb_enc_precise_mbclen(p, e, enc);
+    if (!MBCLEN_CHARFOUND_P(l))
+        return -1;
+    c = rb_enc_mbc_to_codepoint(p, e, enc);
+    if (!rb_enc_isascii(c, enc))
+        return -1;
+    if (len) *len = l;
+    return c;
+}
+
+unsigned int
+rb_enc_codepoint_len(const char *p, const char *e, int *len_p, rb_encoding *enc)
+{
+    int r;
+    if (e <= p)
+        rb_raise(rb_eArgError, "empty string");
+    r = rb_enc_precise_mbclen(p, e, enc);
+    if (!MBCLEN_CHARFOUND_P(r)) {
+	rb_raise(rb_eArgError, "invalid byte sequence in %s", rb_enc_name(enc));
+    }
+    if (len_p) *len_p = MBCLEN_CHARFOUND_LEN(r);
+    return rb_enc_mbc_to_codepoint(p, e, enc);
+}
+
+#undef rb_enc_codepoint
+unsigned int
+rb_enc_codepoint(const char *p, const char *e, rb_encoding *enc)
+{
+    return rb_enc_codepoint_len(p, e, 0, enc);
+}
+
+int
+rb_enc_codelen(int c, rb_encoding *enc)
+{
+    int n = ONIGENC_CODE_TO_MBCLEN(enc,c);
+    if (n == 0) {
+	rb_raise(rb_eArgError, "invalid codepoint 0x%x in %s", c, rb_enc_name(enc));
+    }
+    return n;
+}
+
+#undef rb_enc_code_to_mbclen
+int
+rb_enc_code_to_mbclen(int code, rb_encoding *enc)
+{
+    return ONIGENC_CODE_TO_MBCLEN(enc, code);
+}
+
+int
+rb_enc_toupper(int c, rb_encoding *enc)
+{
+    return (ONIGENC_IS_ASCII_CODE(c)?ONIGENC_ASCII_CODE_TO_UPPER_CASE(c):(c));
+}
+
+int
+rb_enc_tolower(int c, rb_encoding *enc)
+{
+    return (ONIGENC_IS_ASCII_CODE(c)?ONIGENC_ASCII_CODE_TO_LOWER_CASE(c):(c));
+}
+
+/*
+ * call-seq:
+ *   enc.inspect -> string
+ *
+ * Returns a string which represents the encoding for programmers.
+ *
+ *   Encoding::UTF_8.inspect       #=> "#<Encoding:UTF-8>"
+ *   Encoding::ISO_2022_JP.inspect #=> "#<Encoding:ISO-2022-JP (dummy)>"
+ */
+static VALUE
+enc_inspect(VALUE self)
+{
+    rb_encoding *enc;
+
+    if (!is_data_encoding(self)) {
+	not_encoding(self);
+    }
+    if (!(enc = DATA_PTR(self)) || rb_enc_from_index(rb_enc_to_index(enc)) != enc) {
+	rb_raise(rb_eTypeError, "broken Encoding");
+    }
+    return rb_enc_sprintf(rb_usascii_encoding(),
+			  "#<%"PRIsVALUE":%s%s%s>", rb_obj_class(self),
+			  rb_enc_name(enc),
+			  (ENC_DUMMY_P(enc) ? " (dummy)" : ""),
+			  enc_autoload_p(enc) ? " (autoload)" : "");
+}
+
+/*
+ * call-seq:
+ *   enc.name -> string
+ *   enc.to_s -> string
+ *
+ * Returns the name of the encoding.
+ *
+ *   Encoding::UTF_8.name      #=> "UTF-8"
+ */
+static VALUE
+enc_name(VALUE self)
+{
+    return rb_usascii_str_new2(rb_enc_name((rb_encoding*)DATA_PTR(self)));
+}
+
+static int
+enc_names_i(st_data_t name, st_data_t idx, st_data_t args)
+{
+    VALUE *arg = (VALUE *)args;
+
+    if ((int)idx == (int)arg[0]) {
+	VALUE str = rb_usascii_str_new2((char *)name);
+	OBJ_FREEZE(str);
+	rb_ary_push(arg[1], str);
+    }
+    return ST_CONTINUE;
+}
+
+/*
+ * call-seq:
+ *   enc.names -> array
+ *
+ * Returns the list of name and aliases of the encoding.
+ *
+ *   Encoding::WINDOWS_31J.names  #=> ["Windows-31J", "CP932", "csWindows31J"]
+ */
+static VALUE
+enc_names(VALUE self)
+{
+    VALUE args[2];
+
+    args[0] = (VALUE)rb_to_encoding_index(self);
+    args[1] = rb_ary_new2(0);
+    st_foreach(enc_table.names, enc_names_i, (st_data_t)args);
+    return args[1];
+}
+
+/*
+ * call-seq:
+ *   Encoding.list -> [enc1, enc2, ...]
+ *
+ * Returns the list of loaded encodings.
+ *
+ *   Encoding.list
+ *   #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>,
+ *         #<Encoding:ISO-2022-JP (dummy)>]
+ *
+ *   Encoding.find("US-ASCII")
+ *   #=> #<Encoding:US-ASCII>
+ *
+ *   Encoding.list
+ *   #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>,
+ *         #<Encoding:US-ASCII>, #<Encoding:ISO-2022-JP (dummy)>]
+ *
+ */
+static VALUE
+enc_list(VALUE klass)
+{
+    VALUE ary = rb_ary_new2(0);
+    rb_ary_replace(ary, rb_encoding_list);
+    return ary;
+}
+
+/*
+ * call-seq:
+ *   Encoding.find(string) -> enc
+ *
+ * Search the encoding with specified <i>name</i>.
+ * <i>name</i> should be a string.
+ *
+ *   Encoding.find("US-ASCII")  #=> #<Encoding:US-ASCII>
+ *
+ * Names which this method accept are encoding names and aliases
+ * including following special aliases
+ *
+ * "external"::   default external encoding
+ * "internal"::   default internal encoding
+ * "locale"::     locale encoding
+ * "filesystem":: filesystem encoding
+ *
+ * An ArgumentError is raised when no encoding with <i>name</i>.
+ * Only <code>Encoding.find("internal")</code> however returns nil
+ * when no encoding named "internal", in other words, when Ruby has no
+ * default internal encoding.
+ */
+static VALUE
+enc_find(VALUE klass, VALUE enc)
+{
+    int idx;
+    if (is_obj_encoding(enc))
+	return enc;
+    idx = str_to_encindex(enc);
+    if (idx == UNSPECIFIED_ENCODING) return Qnil;
+    return rb_enc_from_encoding_index(idx);
+}
+
+/*
+ * call-seq:
+ *   Encoding.compatible?(obj1, obj2) -> enc or nil
+ *
+ * Checks the compatibility of two objects.
+ *
+ * If the objects are both strings they are compatible when they are
+ * concatenatable.  The encoding of the concatenated string will be returned
+ * if they are compatible, nil if they are not.
+ *
+ *   Encoding.compatible?("\xa1".force_encoding("iso-8859-1"), "b")
+ *   #=> #<Encoding:ISO-8859-1>
+ *
+ *   Encoding.compatible?(
+ *     "\xa1".force_encoding("iso-8859-1"),
+ *     "\xa1\xa1".force_encoding("euc-jp"))
+ *   #=> nil
+ *
+ * If the objects are non-strings their encodings are compatible when they
+ * have an encoding and:
+ * * Either encoding is US-ASCII compatible
+ * * One of the encodings is a 7-bit encoding
+ *
+ */
+static VALUE
+enc_compatible_p(VALUE klass, VALUE str1, VALUE str2)
+{
+    rb_encoding *enc;
+
+    if (!enc_capable(str1)) return Qnil;
+    if (!enc_capable(str2)) return Qnil;
+    enc = rb_enc_compatible(str1, str2);
+    if (!enc) return Qnil;
+    return rb_enc_from_encoding(enc);
+}
+
+/* :nodoc: */
+static VALUE
+enc_dump(int argc, VALUE *argv, VALUE self)
+{
+    rb_scan_args(argc, argv, "01", 0);
+    return enc_name(self);
+}
+
+/* :nodoc: */
+static VALUE
+enc_load(VALUE klass, VALUE str)
+{
+    return enc_find(klass, str);
+}
+
+rb_encoding *
+rb_ascii8bit_encoding(void)
+{
+    if (!enc_table.list) {
+	rb_enc_init();
+    }
+    return enc_table.list[ENCINDEX_ASCII].enc;
+}
+
+int
+rb_ascii8bit_encindex(void)
+{
+    return ENCINDEX_ASCII;
+}
+
+rb_encoding *
+rb_utf8_encoding(void)
+{
+    if (!enc_table.list) {
+	rb_enc_init();
+    }
+    return enc_table.list[ENCINDEX_UTF_8].enc;
+}
+
+int
+rb_utf8_encindex(void)
+{
+    return ENCINDEX_UTF_8;
+}
+
+rb_encoding *
+rb_usascii_encoding(void)
+{
+    if (!enc_table.list) {
+	rb_enc_init();
+    }
+    return enc_table.list[ENCINDEX_US_ASCII].enc;
+}
+
+int
+rb_usascii_encindex(void)
+{
+    return ENCINDEX_US_ASCII;
+}
+
+int
+rb_locale_encindex(void)
+{
+    VALUE charmap = rb_locale_charmap(rb_cEncoding);
+    int idx;
+
+    if (NIL_P(charmap))
+        idx = ENCINDEX_US_ASCII;
+    else if ((idx = rb_enc_find_index(StringValueCStr(charmap))) < 0)
+        idx = ENCINDEX_ASCII;
+
+    if (rb_enc_registered("locale") < 0) {
+# if defined _WIN32
+	void Init_w32_codepage(void);
+	Init_w32_codepage();
+# endif
+	enc_alias_internal("locale", idx);
+    }
+
+    return idx;
+}
+
+rb_encoding *
+rb_locale_encoding(void)
+{
+    return rb_enc_from_index(rb_locale_encindex());
+}
+
+int
+rb_filesystem_encindex(void)
+{
+    int idx = rb_enc_registered("filesystem");
+    if (idx < 0)
+	idx = ENCINDEX_ASCII;
+    return idx;
+}
+
+rb_encoding *
+rb_filesystem_encoding(void)
+{
+    return rb_enc_from_index(rb_filesystem_encindex());
+}
+
+struct default_encoding {
+    int index;			/* -2 => not yet set, -1 => nil */
+    rb_encoding *enc;
+};
+
+static struct default_encoding default_external = {0};
+
+static int
+enc_set_default_encoding(struct default_encoding *def, VALUE encoding, const char *name)
+{
+    int overridden = FALSE;
+
+    if (def->index != -2)
+	/* Already set */
+	overridden = TRUE;
+
+    if (NIL_P(encoding)) {
+	def->index = -1;
+	def->enc = 0;
+	st_insert(enc_table.names, (st_data_t)strdup(name),
+		  (st_data_t)UNSPECIFIED_ENCODING);
+    }
+    else {
+	def->index = rb_enc_to_index(rb_to_encoding(encoding));
+	def->enc = 0;
+	enc_alias_internal(name, def->index);
+    }
+
+    if (def == &default_external)
+	enc_alias_internal("filesystem", Init_enc_set_filesystem_encoding());
+
+    return overridden;
+}
+
+rb_encoding *
+rb_default_external_encoding(void)
+{
+    if (default_external.enc) return default_external.enc;
+
+    if (default_external.index >= 0) {
+        default_external.enc = rb_enc_from_index(default_external.index);
+        return default_external.enc;
+    }
+    else {
+        return rb_locale_encoding();
+    }
+}
+
+VALUE
+rb_enc_default_external(void)
+{
+    return rb_enc_from_encoding(rb_default_external_encoding());
+}
+
+/*
+ * call-seq:
+ *   Encoding.default_external -> enc
+ *
+ * Returns default external encoding.
+ *
+ * The default external encoding is used by default for strings created from
+ * the following locations:
+ *
+ * * CSV
+ * * File data read from disk
+ * * SDBM
+ * * StringIO
+ * * Zlib::GzipReader
+ * * Zlib::GzipWriter
+ * * String#inspect
+ * * Regexp#inspect
+ *
+ * While strings created from these locations will have this encoding, the
+ * encoding may not be valid.  Be sure to check String#valid_encoding?.
+ *
+ * File data written to disk will be transcoded to the default external
+ * encoding when written.
+ *
+ * The default external encoding is initialized by the locale or -E option.
+ */
+static VALUE
+get_default_external(VALUE klass)
+{
+    return rb_enc_default_external();
+}
+
+void
+rb_enc_set_default_external(VALUE encoding)
+{
+    if (NIL_P(encoding)) {
+        rb_raise(rb_eArgError, "default external can not be nil");
+    }
+    enc_set_default_encoding(&default_external, encoding,
+                            "external");
+}
+
+/*
+ * call-seq:
+ *   Encoding.default_external = enc
+ *
+ * Sets default external encoding.  You should not set
+ * Encoding::default_external in ruby code as strings created before changing
+ * the value may have a different encoding from strings created after the value
+ * was changed., instead you should use <tt>ruby -E</tt> to invoke ruby with
+ * the correct default_external.
+ *
+ * See Encoding::default_external for information on how the default external
+ * encoding is used.
+ */
+static VALUE
+set_default_external(VALUE klass, VALUE encoding)
+{
+    rb_warning("setting Encoding.default_external");
+    rb_enc_set_default_external(encoding);
+    return encoding;
+}
+
+static struct default_encoding default_internal = {-2};
+
+rb_encoding *
+rb_default_internal_encoding(void)
+{
+    if (!default_internal.enc && default_internal.index >= 0) {
+        default_internal.enc = rb_enc_from_index(default_internal.index);
+    }
+    return default_internal.enc; /* can be NULL */
+}
+
+VALUE
+rb_enc_default_internal(void)
+{
+    /* Note: These functions cope with default_internal not being set */
+    return rb_enc_from_encoding(rb_default_internal_encoding());
+}
+
+/*
+ * call-seq:
+ *   Encoding.default_internal -> enc
+ *
+ * Returns default internal encoding.  Strings will be transcoded to the
+ * default internal encoding in the following places if the default internal
+ * encoding is not nil:
+ *
+ * * CSV
+ * * Etc.sysconfdir and Etc.systmpdir
+ * * File data read from disk
+ * * File names from Dir
+ * * Integer#chr
+ * * String#inspect and Regexp#inspect
+ * * Strings returned from Readline
+ * * Strings returned from SDBM
+ * * Time#zone
+ * * Values from ENV
+ * * Values in ARGV including $PROGRAM_NAME
+ *
+ * Additionally String#encode and String#encode! use the default internal
+ * encoding if no encoding is given.
+ *
+ * The locale encoding (__ENCODING__), not default_internal, is used as the
+ * encoding of created strings.
+ *
+ * Encoding::default_internal is initialized by the source file's
+ * internal_encoding or -E option.
+ */
+static VALUE
+get_default_internal(VALUE klass)
+{
+    return rb_enc_default_internal();
+}
+
+void
+rb_enc_set_default_internal(VALUE encoding)
+{
+    enc_set_default_encoding(&default_internal, encoding,
+                            "internal");
+}
+
+/*
+ * call-seq:
+ *   Encoding.default_internal = enc or nil
+ *
+ * Sets default internal encoding or removes default internal encoding when
+ * passed nil.  You should not set Encoding::default_internal in ruby code as
+ * strings created before changing the value may have a different encoding
+ * from strings created after the change.  Instead you should use
+ * <tt>ruby -E</tt> to invoke ruby with the correct default_internal.
+ *
+ * See Encoding::default_internal for information on how the default internal
+ * encoding is used.
+ */
+static VALUE
+set_default_internal(VALUE klass, VALUE encoding)
+{
+    rb_warning("setting Encoding.default_internal");
+    rb_enc_set_default_internal(encoding);
+    return encoding;
+}
+
+/*
+ * call-seq:
+ *   Encoding.locale_charmap -> string
+ *
+ * Returns the locale charmap name.
+ * It returns nil if no appropriate information.
+ *
+ *   Debian GNU/Linux
+ *     LANG=C
+ *       Encoding.locale_charmap  #=> "ANSI_X3.4-1968"
+ *     LANG=ja_JP.EUC-JP
+ *       Encoding.locale_charmap  #=> "EUC-JP"
+ *
+ *   SunOS 5
+ *     LANG=C
+ *       Encoding.locale_charmap  #=> "646"
+ *     LANG=ja
+ *       Encoding.locale_charmap  #=> "eucJP"
+ *
+ * The result is highly platform dependent.
+ * So Encoding.find(Encoding.locale_charmap) may cause an error.
+ * If you need some encoding object even for unknown locale,
+ * Encoding.find("locale") can be used.
+ *
+ */
+static void
+set_encoding_const(const char *name, rb_encoding *enc)
+{
+    VALUE encoding = rb_enc_from_encoding(enc);
+    char *s = (char *)name;
+    int haslower = 0, hasupper = 0, valid = 0;
+
+    if (ISDIGIT(*s)) return;
+    if (ISUPPER(*s)) {
+	hasupper = 1;
+	while (*++s && (ISALNUM(*s) || *s == '_')) {
+	    if (ISLOWER(*s)) haslower = 1;
+	}
+    }
+    if (!*s) {
+	if (s - name > ENCODING_NAMELEN_MAX) return;
+	valid = 1;
+	rb_define_const(rb_cEncoding, name, encoding);
+    }
+    if (!valid || haslower) {
+	size_t len = s - name;
+	if (len > ENCODING_NAMELEN_MAX) return;
+	if (!haslower || !hasupper) {
+	    do {
+		if (ISLOWER(*s)) haslower = 1;
+		if (ISUPPER(*s)) hasupper = 1;
+	    } while (*++s && (!haslower || !hasupper));
+	    len = s - name;
+	}
+	len += strlen(s);
+	if (len++ > ENCODING_NAMELEN_MAX) return;
+	MEMCPY(s = ALLOCA_N(char, len), name, char, len);
+	name = s;
+	if (!valid) {
+	    if (ISLOWER(*s)) *s = ONIGENC_ASCII_CODE_TO_UPPER_CASE((int)*s);
+	    for (; *s; ++s) {
+		if (!ISALNUM(*s)) *s = '_';
+	    }
+	    if (hasupper) {
+		rb_define_const(rb_cEncoding, name, encoding);
+	    }
+	}
+	if (haslower) {
+	    for (s = (char *)name; *s; ++s) {
+		if (ISLOWER(*s)) *s = ONIGENC_ASCII_CODE_TO_UPPER_CASE((int)*s);
+	    }
+	    rb_define_const(rb_cEncoding, name, encoding);
+	}
+    }
+}
+
+static int
+rb_enc_name_list_i(st_data_t name, st_data_t idx, st_data_t arg)
+{
+    VALUE ary = (VALUE)arg;
+    VALUE str = rb_usascii_str_new2((char *)name);
+    OBJ_FREEZE(str);
+    rb_ary_push(ary, str);
+    return ST_CONTINUE;
+}
+
+/*
+ * call-seq:
+ *   Encoding.name_list -> ["enc1", "enc2", ...]
+ *
+ * Returns the list of available encoding names.
+ *
+ *   Encoding.name_list
+ *   #=> ["US-ASCII", "ASCII-8BIT", "UTF-8",
+ *         "ISO-8859-1", "Shift_JIS", "EUC-JP",
+ *         "Windows-31J",
+ *         "BINARY", "CP932", "eucJP"]
+ *
+ */
+
+static VALUE
+rb_enc_name_list(VALUE klass)
+{
+    VALUE ary = rb_ary_new2(enc_table.names->num_entries);
+    st_foreach(enc_table.names, rb_enc_name_list_i, (st_data_t)ary);
+    return ary;
+}
+
+static int
+rb_enc_aliases_enc_i(st_data_t name, st_data_t orig, st_data_t arg)
+{
+    VALUE *p = (VALUE *)arg;
+    VALUE aliases = p[0], ary = p[1];
+    int idx = (int)orig;
+    VALUE key, str = rb_ary_entry(ary, idx);
+
+    if (NIL_P(str)) {
+	rb_encoding *enc = rb_enc_from_index(idx);
+
+	if (!enc) return ST_CONTINUE;
+	if (STRCASECMP((char*)name, rb_enc_name(enc)) == 0) {
+	    return ST_CONTINUE;
+	}
+	str = rb_usascii_str_new2(rb_enc_name(enc));
+	OBJ_FREEZE(str);
+	rb_ary_store(ary, idx, str);
+    }
+    key = rb_usascii_str_new2((char *)name);
+    OBJ_FREEZE(key);
+    rb_hash_aset(aliases, key, str);
+    return ST_CONTINUE;
+}
+
+/*
+ * call-seq:
+ *   Encoding.aliases -> {"alias1" => "orig1", "alias2" => "orig2", ...}
+ *
+ * Returns the hash of available encoding alias and original encoding name.
+ *
+ *   Encoding.aliases
+ *   #=> {"BINARY"=>"ASCII-8BIT", "ASCII"=>"US-ASCII", "ANSI_X3.4-1986"=>"US-ASCII",
+ *         "SJIS"=>"Shift_JIS", "eucJP"=>"EUC-JP", "CP932"=>"Windows-31J"}
+ *
+ */
+
+static VALUE
+rb_enc_aliases(VALUE klass)
+{
+    VALUE aliases[2];
+    aliases[0] = rb_hash_new();
+    aliases[1] = rb_ary_new();
+    st_foreach(enc_table.names, rb_enc_aliases_enc_i, (st_data_t)aliases);
+    return aliases[0];
+}
+
+/*
+ * An Encoding instance represents a character encoding usable in Ruby. It is
+ * defined as a constant under the Encoding namespace. It has a name and
+ * optionally, aliases:
+ *
+ *   Encoding::ISO_8859_1.name
+ *   #=> #<Encoding:ISO-8859-1>
+ *
+ *   Encoding::ISO_8859_1.names
+ *   #=> ["ISO-8859-1", "ISO8859-1"]
+ *
+ * Ruby methods dealing with encodings return or accept Encoding instances as
+ * arguments (when a method accepts an Encoding instance as an argument, it
+ * can be passed an Encoding name or alias instead).
+ *
+ *   "some string".encoding
+ *   #=> #<Encoding:UTF-8>
+ *
+ *   string = "some string".encode(Encoding::ISO_8859_1)
+ *   #=> "some string"
+ *   string.encoding
+ *   #=> #<Encoding:ISO-8859-1>
+ *
+ *   "some string".encode "ISO-8859-1"
+ *   #=> "some string"
+ *
+ * <code>Encoding::ASCII_8BIT</code> is a special encoding that is usually
+ * used for a byte string, not a character string. But as the name insists,
+ * its characters in the range of ASCII are considered as ASCII characters.
+ * This is useful when you use ASCII-8BIT characters with other ASCII
+ * compatible characters.
+ *
+ * == Changing an encoding
+ *
+ * The associated Encoding of a String can be changed in two different ways.
+ *
+ * First, it is possible to set the Encoding of a string to a new Encoding
+ * without changing the internal byte representation of the string, with
+ * String#force_encoding. This is how you can tell Ruby the correct encoding
+ * of a string.
+ *
+ *   string
+ *   #=> "R\xC3\xA9sum\xC3\xA9"
+ *   string.encoding
+ *   #=> #<Encoding:ISO-8859-1>
+ *   string.force_encoding(Encoding::UTF_8)
+ *   #=> "R\u00E9sum\u00E9"
+ *
+ * Second, it is possible to transcode a string, i.e. translate its internal
+ * byte representation to another encoding. Its associated encoding is also
+ * set to the other encoding. See String#encode for the various forms of
+ * transcoding, and the Encoding::Converter class for additional control over
+ * the transcoding process.
+ *
+ *   string
+ *   #=> "R\u00E9sum\u00E9"
+ *   string.encoding
+ *   #=> #<Encoding:UTF-8>
+ *   string = string.encode!(Encoding::ISO_8859_1)
+ *   #=> "R\xE9sum\xE9"
+ *   string.encoding
+ *   #=> #<Encoding::ISO-8859-1>
+ *
+ * == Script encoding
+ *
+ * All Ruby script code has an associated Encoding which any String literal
+ * created in the source code will be associated to.
+ *
+ * The default script encoding is <code>Encoding::UTF-8</code> after v2.0, but it can
+ * be changed by a magic comment on the first line of the source code file (or
+ * second line, if there is a shebang line on the first). The comment must
+ * contain the word <code>coding</code> or <code>encoding</code>, followed
+ * by a colon, space and the Encoding name or alias:
+ *
+ *   # encoding: UTF-8
+ *
+ *   "some string".encoding
+ *   #=> #<Encoding:UTF-8>
+ *
+ * The <code>__ENCODING__</code> keyword returns the script encoding of the file
+ * which the keyword is written:
+ *
+ *   # encoding: ISO-8859-1
+ *
+ *   __ENCODING__
+ *   #=> #<Encoding:ISO-8859-1>
+ *
+ * <code>ruby -K</code> will change the default locale encoding, but this is
+ * not recommended. Ruby source files should declare its script encoding by a
+ * magic comment even when they only depend on US-ASCII strings or regular
+ * expressions.
+ *
+ * == Locale encoding
+ *
+ * The default encoding of the environment. Usually derived from locale.
+ *
+ * see Encoding.locale_charmap, Encoding.find('locale')
+ *
+ * == Filesystem encoding
+ *
+ * The default encoding of strings from the filesystem of the environment.
+ * This is used for strings of file names or paths.
+ *
+ * see Encoding.find('filesystem')
+ *
+ * == External encoding
+ *
+ * Each IO object has an external encoding which indicates the encoding that
+ * Ruby will use to read its data. By default Ruby sets the external encoding
+ * of an IO object to the default external encoding. The default external
+ * encoding is set by locale encoding or the interpreter <code>-E</code> option.
+ * Encoding.default_external returns the current value of the external
+ * encoding.
+ *
+ *   ENV["LANG"]
+ *   #=> "UTF-8"
+ *   Encoding.default_external
+ *   #=> #<Encoding:UTF-8>
+ *
+ *   $ ruby -E ISO-8859-1 -e "p Encoding.default_external"
+ *   #<Encoding:ISO-8859-1>
+ *
+ *   $ LANG=C ruby -e 'p Encoding.default_external'
+ *   #<Encoding:US-ASCII>
+ *
+ * The default external encoding may also be set through
+ * Encoding.default_external=, but you should not do this as strings created
+ * before and after the change will have inconsistent encodings.  Instead use
+ * <code>ruby -E</code> to invoke ruby with the correct external encoding.
+ *
+ * When you know that the actual encoding of the data of an IO object is not
+ * the default external encoding, you can reset its external encoding with
+ * IO#set_encoding or set it at IO object creation (see IO.new options).
+ *
+ * == Internal encoding
+ *
+ * To process the data of an IO object which has an encoding different
+ * from its external encoding, you can set its internal encoding. Ruby will use
+ * this internal encoding to transcode the data when it is read from the IO
+ * object.
+ *
+ * Conversely, when data is written to the IO object it is transcoded from the
+ * internal encoding to the external encoding of the IO object.
+ *
+ * The internal encoding of an IO object can be set with
+ * IO#set_encoding or at IO object creation (see IO.new options).
+ *
+ * The internal encoding is optional and when not set, the Ruby default
+ * internal encoding is used. If not explicitly set this default internal
+ * encoding is +nil+ meaning that by default, no transcoding occurs.
+ *
+ * The default internal encoding can be set with the interpreter option
+ * <code>-E</code>. Encoding.default_internal returns the current internal
+ * encoding.
+ *
+ *    $ ruby -e 'p Encoding.default_internal'
+ *    nil
+ *
+ *    $ ruby -E ISO-8859-1:UTF-8 -e "p [Encoding.default_external, \
+ *      Encoding.default_internal]"
+ *    [#<Encoding:ISO-8859-1>, #<Encoding:UTF-8>]
+ *
+ * The default internal encoding may also be set through
+ * Encoding.default_internal=, but you should not do this as strings created
+ * before and after the change will have inconsistent encodings.  Instead use
+ * <code>ruby -E</code> to invoke ruby with the correct internal encoding.
+ *
+ * == IO encoding example
+ *
+ * In the following example a UTF-8 encoded string "R\u00E9sum\u00E9" is transcoded for
+ * output to ISO-8859-1 encoding, then read back in and transcoded to UTF-8:
+ *
+ *   string = "R\u00E9sum\u00E9"
+ *
+ *   open("transcoded.txt", "w:ISO-8859-1") do |io|
+ *     io.write(string)
+ *   end
+ *
+ *   puts "raw text:"
+ *   p File.binread("transcoded.txt")
+ *   puts
+ *
+ *   open("transcoded.txt", "r:ISO-8859-1:UTF-8") do |io|
+ *     puts "transcoded text:"
+ *     p io.read
+ *   end
+ *
+ * While writing the file, the internal encoding is not specified as it is
+ * only necessary for reading.  While reading the file both the internal and
+ * external encoding must be specified to obtain the correct result.
+ *
+ *   $ ruby t.rb
+ *   raw text:
+ *   "R\xE9sum\xE9"
+ *
+ *   transcoded text:
+ *   "R\u00E9sum\u00E9"
+ *
+ */
+
+void
+Init_Encoding(void)
+{
+#undef rb_intern
+#define rb_intern(str) rb_intern_const(str)
+    VALUE list;
+    int i;
+
+    rb_cEncoding = rb_define_class("Encoding", rb_cObject);
+    rb_undef_alloc_func(rb_cEncoding);
+    rb_undef_method(CLASS_OF(rb_cEncoding), "new");
+    rb_define_method(rb_cEncoding, "to_s", enc_name, 0);
+    rb_define_method(rb_cEncoding, "inspect", enc_inspect, 0);
+    rb_define_method(rb_cEncoding, "name", enc_name, 0);
+    rb_define_method(rb_cEncoding, "names", enc_names, 0);
+    rb_define_method(rb_cEncoding, "dummy?", enc_dummy_p, 0);
+    rb_define_method(rb_cEncoding, "ascii_compatible?", enc_ascii_compatible_p, 0);
+    rb_define_method(rb_cEncoding, "replicate", enc_replicate, 1);
+    rb_define_singleton_method(rb_cEncoding, "list", enc_list, 0);
+    rb_define_singleton_method(rb_cEncoding, "name_list", rb_enc_name_list, 0);
+    rb_define_singleton_method(rb_cEncoding, "aliases", rb_enc_aliases, 0);
+    rb_define_singleton_method(rb_cEncoding, "find", enc_find, 1);
+    rb_define_singleton_method(rb_cEncoding, "compatible?", enc_compatible_p, 2);
+
+    rb_define_method(rb_cEncoding, "_dump", enc_dump, -1);
+    rb_define_singleton_method(rb_cEncoding, "_load", enc_load, 1);
+
+    rb_define_singleton_method(rb_cEncoding, "default_external", get_default_external, 0);
+    rb_define_singleton_method(rb_cEncoding, "default_external=", set_default_external, 1);
+    rb_define_singleton_method(rb_cEncoding, "default_internal", get_default_internal, 0);
+    rb_define_singleton_method(rb_cEncoding, "default_internal=", set_default_internal, 1);
+    rb_define_singleton_method(rb_cEncoding, "locale_charmap", rb_locale_charmap, 0);
+
+    list = rb_ary_new2(enc_table.count);
+    RBASIC_CLEAR_CLASS(list);
+    rb_encoding_list = list;
+    rb_gc_register_mark_object(list);
+
+    for (i = 0; i < enc_table.count; ++i) {
+	rb_ary_push(list, enc_new(enc_table.list[i].enc));
+    }
+}
+
+/* locale insensitive ctype functions */
+
+#define ctype_test(c, ctype) \
+    (rb_isascii(c) && ONIGENC_IS_ASCII_CODE_CTYPE((c), (ctype)))
+
+int rb_isalnum(int c) { return ctype_test(c, ONIGENC_CTYPE_ALNUM); }
+int rb_isalpha(int c) { return ctype_test(c, ONIGENC_CTYPE_ALPHA); }
+int rb_isblank(int c) { return ctype_test(c, ONIGENC_CTYPE_BLANK); }
+int rb_iscntrl(int c) { return ctype_test(c, ONIGENC_CTYPE_CNTRL); }
+int rb_isdigit(int c) { return ctype_test(c, ONIGENC_CTYPE_DIGIT); }
+int rb_isgraph(int c) { return ctype_test(c, ONIGENC_CTYPE_GRAPH); }
+int rb_islower(int c) { return ctype_test(c, ONIGENC_CTYPE_LOWER); }
+int rb_isprint(int c) { return ctype_test(c, ONIGENC_CTYPE_PRINT); }
+int rb_ispunct(int c) { return ctype_test(c, ONIGENC_CTYPE_PUNCT); }
+int rb_isspace(int c) { return ctype_test(c, ONIGENC_CTYPE_SPACE); }
+int rb_isupper(int c) { return ctype_test(c, ONIGENC_CTYPE_UPPER); }
+int rb_isxdigit(int c) { return ctype_test(c, ONIGENC_CTYPE_XDIGIT); }
+
+int
+rb_tolower(int c)
+{
+    return rb_isascii(c) ? ONIGENC_ASCII_CODE_TO_LOWER_CASE(c) : c;
+}
+
+int
+rb_toupper(int c)
+{
+    return rb_isascii(c) ? ONIGENC_ASCII_CODE_TO_UPPER_CASE(c) : c;
+}
+
+void
+rb_enc_foreach_name(int (*func)(st_data_t name, st_data_t idx, st_data_t arg), st_data_t arg)
+{
+    st_foreach(enc_table.names, func, arg);
+}