encoding.h: constify rb_encoding

* include/ruby/encoding.h: constify `rb_encoding` itself, not only
  arguments.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46322 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

11 files changed, 158 insertions, 155 deletions

diff --git a/dir.c b/dir.c
index c7bddf4de2..c784a6f162 100644
--- a/dir.c
+++ b/dir.c
@@ -1307,17 +1307,17 @@ struct glob_args {
     rb_encoding *enc;
 };
 
+#define glob_call_func(func, path, arg, enc) (*(func))((path), (arg), (void *)(enc))
+
 static VALUE
 glob_func_caller(VALUE val)
 {
     struct glob_args *args = (struct glob_args *)val;
 
-    (*args->func)(args->path, args->value, args->enc);
+    glob_call_func(args->func, args->path, args->value, args->enc);
     return Qnil;
 }
 
-#define glob_call_func(func, path, arg, enc) (*(func))((path), (arg), (enc))
-
 static int
 glob_helper(
     const char *path,
@@ -1724,7 +1724,7 @@ ruby_brace_expand(const char *str, int flags, ruby_glob_func *func, VALUE arg,
 	GLOB_FREE(buf);
     }
     else if (!lbrace && !rbrace) {
-	status = (*func)(s, arg, enc);
+	status = glob_call_func(func, s, arg, enc);
     }
 
     return status;
diff --git a/encoding.c b/encoding.c
index 98d83e49d9..8e05b82f10 100644
--- a/encoding.c
+++ b/encoding.c
@@ -20,9 +20,11 @@
 #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, const rb_encoding *encoding);
+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);
@@ -80,7 +82,7 @@ static const rb_data_type_t encoding_data_type = {
 static VALUE
 enc_new(rb_encoding *encoding)
 {
-    return TypedData_Wrap_Struct(rb_cEncoding, &encoding_data_type, encoding);
+    return TypedData_Wrap_Struct(rb_cEncoding, &encoding_data_type, (void *)encoding);
 }
 
 static VALUE
@@ -99,7 +101,7 @@ rb_enc_from_encoding_index(int idx)
 }
 
 VALUE
-rb_enc_from_encoding(const rb_encoding *encoding)
+rb_enc_from_encoding(rb_encoding *encoding)
 {
     int idx;
     if (!encoding) return Qnil;
@@ -254,10 +256,10 @@ enc_table_expand(int newsize)
 }
 
 static int
-enc_register_at(int index, const char *name, const rb_encoding *base_encoding)
+enc_register_at(int index, const char *name, rb_encoding *base_encoding)
 {
     struct rb_encoding_entry *ent = &enc_table.list[index];
-    rb_encoding *encoding;
+    rb_raw_encoding *encoding;
     VALUE list;
 
     if (!valid_encoding_name_p(name)) return -1;
@@ -267,18 +269,19 @@ enc_register_at(int index, const char *name, const rb_encoding *base_encoding)
     else if (STRCASECMP(name, ent->name)) {
 	return -1;
     }
-    if (!ent->enc) {
-	ent->enc = xmalloc(sizeof(rb_encoding));
+    encoding = (rb_raw_encoding *)ent->enc;
+    if (!encoding) {
+	encoding = xmalloc(sizeof(rb_encoding));
     }
     if (base_encoding) {
-	*ent->enc = *base_encoding;
+	*encoding = *base_encoding;
     }
     else {
-	memset(ent->enc, 0, sizeof(*ent->enc));
+	memset(encoding, 0, sizeof(*ent->enc));
     }
-    encoding = 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))) {
@@ -289,7 +292,7 @@ enc_register_at(int index, const char *name, const rb_encoding *base_encoding)
 }
 
 static int
-enc_register(const char *name, const rb_encoding *encoding)
+enc_register(const char *name, rb_encoding *encoding)
 {
     int index = enc_table.count;
 
@@ -298,11 +301,11 @@ enc_register(const char *name, const rb_encoding *encoding)
     return enc_register_at(index - 1, name, encoding);
 }
 
-static void set_encoding_const(const char *, const rb_encoding *);
+static void set_encoding_const(const char *, rb_encoding *);
 int rb_enc_registered(const char *name);
 
 int
-rb_enc_register(const char *name, const rb_encoding *encoding)
+rb_enc_register(const char *name, rb_encoding *encoding)
 {
     int index = rb_enc_registered(name);
 
@@ -349,7 +352,7 @@ set_base_encoding(int index, rb_encoding *base)
     rb_encoding *enc = enc_table.list[index].enc;
 
     enc_table.list[index].base = base;
-    if (rb_enc_dummy_p(base)) ENC_SET_DUMMY(enc);
+    if (rb_enc_dummy_p(base)) ENC_SET_DUMMY((rb_raw_encoding *)enc);
     return enc;
 }
 
@@ -373,7 +376,7 @@ rb_enc_set_dummy(int index)
 {
     rb_encoding *enc = enc_table.list[index].enc;
 
-    ENC_SET_DUMMY(enc);
+    ENC_SET_DUMMY((rb_raw_encoding *)enc);
     return index;
 }
 
@@ -440,7 +443,7 @@ 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(enc);
+    ENC_SET_DUMMY((rb_raw_encoding *)enc);
     return index;
 }
 
@@ -451,7 +454,7 @@ rb_encdb_dummy(const char *name)
 					 rb_enc_registered(name));
     rb_encoding *enc = enc_table.list[index].enc;
 
-    ENC_SET_DUMMY(enc);
+    ENC_SET_DUMMY((rb_raw_encoding *)enc);
     return index;
 }
 
@@ -494,7 +497,7 @@ enc_ascii_compatible_p(VALUE enc)
  * Returns 1 when the encoding is Unicode series other than UTF-7 else 0.
  */
 int
-rb_enc_unicode_p(const rb_encoding *enc)
+rb_enc_unicode_p(rb_encoding *enc)
 {
     return ONIGENC_IS_UNICODE(enc);
 }
@@ -554,7 +557,7 @@ rb_encdb_alias(const char *alias, const char *orig)
 void
 rb_encdb_set_unicode(int index)
 {
-    rb_enc_from_index(index)->flags |= ONIGENC_FLAG_UNICODE;
+    ((rb_raw_encoding *)rb_enc_from_index(index))->flags |= ONIGENC_FLAG_UNICODE;
 }
 
 extern rb_encoding OnigEncodingUTF_8;
@@ -672,7 +675,7 @@ enc_autoload(rb_encoding *enc)
 	}
 	i = enc->ruby_encoding_index;
 	enc_register_at(i & ENC_INDEX_MASK, rb_enc_name(enc), base);
-	enc->ruby_encoding_index = i;
+	((rb_raw_encoding *)enc)->ruby_encoding_index = i;
     }
     else {
 	i = load_encoding(rb_enc_name(enc));
@@ -825,7 +828,7 @@ rb_enc_associate_index(VALUE obj, int idx)
 }
 
 VALUE
-rb_enc_associate(VALUE obj, const rb_encoding *enc)
+rb_enc_associate(VALUE obj, rb_encoding *enc)
 {
     return rb_enc_associate_index(obj, rb_enc_to_index(enc));
 }
@@ -939,13 +942,13 @@ rb_obj_encoding(VALUE obj)
 }
 
 int
-rb_enc_fast_mbclen(const char *p, const char *e, const rb_encoding *enc)
+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, const rb_encoding *enc)
+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)
@@ -957,7 +960,7 @@ rb_enc_mbclen(const char *p, const char *e, const rb_encoding *enc)
 }
 
 int
-rb_enc_precise_mbclen(const char *p, const char *e, const rb_encoding *enc)
+rb_enc_precise_mbclen(const char *p, const char *e, rb_encoding *enc)
 {
     int n;
     if (e <= p)
@@ -969,7 +972,7 @@ rb_enc_precise_mbclen(const char *p, const char *e, const rb_encoding *enc)
 }
 
 int
-rb_enc_ascget(const char *p, const char *e, int *len, const rb_encoding *enc)
+rb_enc_ascget(const char *p, const char *e, int *len, rb_encoding *enc)
 {
     unsigned int c, l;
     if (e <= p)
@@ -992,7 +995,7 @@ rb_enc_ascget(const char *p, const char *e, int *len, const rb_encoding *enc)
 }
 
 unsigned int
-rb_enc_codepoint_len(const char *p, const char *e, int *len_p, const rb_encoding *enc)
+rb_enc_codepoint_len(const char *p, const char *e, int *len_p, rb_encoding *enc)
 {
     int r;
     if (e <= p)
@@ -1007,13 +1010,13 @@ rb_enc_codepoint_len(const char *p, const char *e, int *len_p, const rb_encoding
 
 #undef rb_enc_codepoint
 unsigned int
-rb_enc_codepoint(const char *p, const char *e, const rb_encoding *enc)
+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, const rb_encoding *enc)
+rb_enc_codelen(int c, rb_encoding *enc)
 {
     int n = ONIGENC_CODE_TO_MBCLEN(enc,c);
     if (n == 0) {
@@ -1024,19 +1027,19 @@ rb_enc_codelen(int c, const rb_encoding *enc)
 
 #undef rb_enc_code_to_mbclen
 int
-rb_enc_code_to_mbclen(int code, const rb_encoding *enc)
+rb_enc_code_to_mbclen(int code, rb_encoding *enc)
 {
     return ONIGENC_CODE_TO_MBCLEN(enc, code);
 }
 
 int
-rb_enc_toupper(int c, const rb_encoding *enc)
+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, const rb_encoding *enc)
+rb_enc_tolower(int c, rb_encoding *enc)
 {
     return (ONIGENC_IS_ASCII_CODE(c)?ONIGENC_ASCII_CODE_TO_LOWER_CASE(c):(c));
 }
@@ -1544,7 +1547,7 @@ VALUE
 rb_locale_charmap(VALUE klass);
 
 static void
-set_encoding_const(const char *name, const rb_encoding *enc)
+set_encoding_const(const char *name, rb_encoding *enc)
 {
     VALUE encoding = rb_enc_from_encoding(enc);
     char *s = (char *)name;
diff --git a/error.c b/error.c
index 79c36c5171..71375c3bea 100644
--- a/error.c
+++ b/error.c
@@ -1891,7 +1891,7 @@ Init_Exception(void)
 }
 
 void
-rb_enc_raise(const rb_encoding *enc, VALUE exc, const char *fmt, ...)
+rb_enc_raise(rb_encoding *enc, VALUE exc, const char *fmt, ...)
 {
     va_list args;
     VALUE mesg;
diff --git a/file.c b/file.c
index e415288164..e6a225747d 100644
--- a/file.c
+++ b/file.c
@@ -2953,7 +2953,7 @@ skiproot(const char *path, const char *end, rb_encoding *enc)
 
 #define nextdirsep rb_enc_path_next
 char *
-rb_enc_path_next(const char *s, const char *e, const rb_encoding *enc)
+rb_enc_path_next(const char *s, const char *e, rb_encoding *enc)
 {
     while (s < e && !isdirsep(*s)) {
 	Inc(s, e, enc);
@@ -2967,7 +2967,7 @@ rb_enc_path_next(const char *s, const char *e, const rb_encoding *enc)
 #define skipprefix(path, end, enc) (path)
 #endif
 char *
-rb_enc_path_skip_prefix(const char *path, const char *end, const rb_encoding *enc)
+rb_enc_path_skip_prefix(const char *path, const char *end, rb_encoding *enc)
 {
 #if defined(DOSISH_UNC) || defined(DOSISH_DRIVE_LETTER)
 #ifdef DOSISH_UNC
@@ -3001,7 +3001,7 @@ skipprefixroot(const char *path, const char *end, rb_encoding *enc)
 
 #define strrdirsep rb_enc_path_last_separator
 char *
-rb_enc_path_last_separator(const char *path, const char *end, const rb_encoding *enc)
+rb_enc_path_last_separator(const char *path, const char *end, rb_encoding *enc)
 {
     char *last = NULL;
     while (path < end) {
@@ -3019,7 +3019,7 @@ rb_enc_path_last_separator(const char *path, const char *end, const rb_encoding
 }
 
 static char *
-chompdirsep(const char *path, const char *end, const rb_encoding *enc)
+chompdirsep(const char *path, const char *end, rb_encoding *enc)
 {
     while (path < end) {
 	if (isdirsep(*path)) {
@@ -3035,7 +3035,7 @@ chompdirsep(const char *path, const char *end, const rb_encoding *enc)
 }
 
 char *
-rb_enc_path_end(const char *path, const char *end, const rb_encoding *enc)
+rb_enc_path_end(const char *path, const char *end, rb_encoding *enc)
 {
     if (path < end && isdirsep(*path)) path++;
     return chompdirsep(path, end, enc);
@@ -3043,7 +3043,7 @@ rb_enc_path_end(const char *path, const char *end, const rb_encoding *enc)
 
 #if USE_NTFS
 static char *
-ntfs_tail(const char *path, const char *end, const rb_encoding *enc)
+ntfs_tail(const char *path, const char *end, rb_encoding *enc)
 {
     while (path < end && *path == '.') path++;
     while (path < end && *path != ':') {
@@ -3833,7 +3833,7 @@ rb_file_s_realdirpath(int argc, VALUE *argv, VALUE klass)
 }
 
 static size_t
-rmext(const char *p, long l0, long l1, const char *e, long l2, const rb_encoding *enc)
+rmext(const char *p, long l0, long l1, const char *e, long l2, rb_encoding *enc)
 {
     int len1, len2;
     unsigned int c;
@@ -3869,7 +3869,7 @@ rmext(const char *p, long l0, long l1, const char *e, long l2, const rb_encoding
 }
 
 const char *
-ruby_enc_find_basename(const char *name, long *baselen, long *alllen, const rb_encoding *enc)
+ruby_enc_find_basename(const char *name, long *baselen, long *alllen, rb_encoding *enc)
 {
     const char *p, *q, *e, *end;
 #if defined DOSISH_DRIVE_LETTER || defined DOSISH_UNC
@@ -4064,7 +4064,7 @@ rb_file_dirname(VALUE fname)
  *
  */
 const char *
-ruby_enc_find_extname(const char *name, long *len, const rb_encoding *enc)
+ruby_enc_find_extname(const char *name, long *len, rb_encoding *enc)
 {
     const char *p, *e, *end = name + (len ? *len : (long)strlen(name));
 
diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index 790e3dee9d..aab05b4528 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -68,7 +68,7 @@ RUBY_SYMBOL_EXPORT_BEGIN
         ENC_CODERANGE_SET(rb_encoding_coderange_obj, (cr)); \
     } while (0)
 
-typedef OnigEncodingType rb_encoding;
+typedef const OnigEncodingType rb_encoding;
 
 int rb_char_to_option_kcode(int c, int *option, int *kcode);
 
@@ -79,30 +79,30 @@ int rb_enc_get_index(VALUE obj);
 void rb_enc_set_index(VALUE obj, int encindex);
 int rb_enc_find_index(const char *name);
 int rb_to_encoding_index(VALUE);
-rb_encoding* rb_to_encoding(VALUE);
-rb_encoding* rb_find_encoding(VALUE);
-rb_encoding* rb_enc_get(VALUE);
-rb_encoding* rb_enc_compatible(VALUE,VALUE);
-rb_encoding* rb_enc_check(VALUE,VALUE);
+rb_encoding *rb_to_encoding(VALUE);
+rb_encoding *rb_find_encoding(VALUE);
+rb_encoding *rb_enc_get(VALUE);
+rb_encoding *rb_enc_compatible(VALUE,VALUE);
+rb_encoding *rb_enc_check(VALUE,VALUE);
 VALUE rb_enc_associate_index(VALUE, int);
-VALUE rb_enc_associate(VALUE, const rb_encoding*);
+VALUE rb_enc_associate(VALUE, rb_encoding*);
 void rb_enc_copy(VALUE dst, VALUE src);
 
-VALUE rb_enc_str_new(const char*, long, const rb_encoding*);
-VALUE rb_enc_str_new_cstr(const char*, const rb_encoding*);
-VALUE rb_enc_reg_new(const char*, long, const rb_encoding*, int);
-PRINTF_ARGS(VALUE rb_enc_sprintf(const rb_encoding *, const char*, ...), 2, 3);
-VALUE rb_enc_vsprintf(const rb_encoding *, const char*, va_list);
-long rb_enc_strlen(const char*, const char*, const rb_encoding*);
-char* rb_enc_nth(const char*, const char*, long, const rb_encoding*);
+VALUE rb_enc_str_new(const char*, long, rb_encoding*);
+VALUE rb_enc_str_new_cstr(const char*, rb_encoding*);
+VALUE rb_enc_reg_new(const char*, long, rb_encoding*, int);
+PRINTF_ARGS(VALUE rb_enc_sprintf(rb_encoding *, const char*, ...), 2, 3);
+VALUE rb_enc_vsprintf(rb_encoding *, const char*, va_list);
+long rb_enc_strlen(const char*, const char*, rb_encoding*);
+char* rb_enc_nth(const char*, const char*, long, rb_encoding*);
 VALUE rb_obj_encoding(VALUE);
-VALUE rb_enc_str_buf_cat(VALUE str, const char *ptr, long len, const rb_encoding *enc);
-VALUE rb_enc_uint_chr(unsigned int code, const rb_encoding *enc);
+VALUE rb_enc_str_buf_cat(VALUE str, const char *ptr, long len, rb_encoding *enc);
+VALUE rb_enc_uint_chr(unsigned int code, rb_encoding *enc);
 
-VALUE rb_external_str_new_with_enc(const char *ptr, long len, const rb_encoding *);
-VALUE rb_str_export_to_enc(VALUE, const rb_encoding *);
-VALUE rb_str_conv_enc(VALUE str, const rb_encoding *from, const rb_encoding *to);
-VALUE rb_str_conv_enc_opts(VALUE str, const rb_encoding *from, const rb_encoding *to, int ecflags, VALUE ecopts);
+VALUE rb_external_str_new_with_enc(const char *ptr, long len, rb_encoding *);
+VALUE rb_str_export_to_enc(VALUE, rb_encoding *);
+VALUE rb_str_conv_enc(VALUE str, rb_encoding *from, rb_encoding *to);
+VALUE rb_str_conv_enc_opts(VALUE str, rb_encoding *from, rb_encoding *to, int ecflags, VALUE ecopts);
 
 #if defined(__GNUC__) && !defined(__PCC__)
 #define rb_enc_str_new_cstr(str, enc) __extension__ (	\
@@ -113,13 +113,13 @@ VALUE rb_str_conv_enc_opts(VALUE str, const rb_encoding *from, const rb_encoding
 })
 #endif
 
-PRINTF_ARGS(NORETURN(void rb_enc_raise(const rb_encoding *, VALUE, const char*, ...)), 3, 4);
+PRINTF_ARGS(NORETURN(void rb_enc_raise(rb_encoding *, VALUE, const char*, ...)), 3, 4);
 
 /* index -> rb_encoding */
-rb_encoding* rb_enc_from_index(int idx);
+rb_encoding *rb_enc_from_index(int idx);
 
 /* name -> rb_encoding */
-rb_encoding * rb_enc_find(const char *name);
+rb_encoding *rb_enc_find(const char *name);
 
 /* rb_encoding * -> name */
 #define rb_enc_name(enc) (enc)->name
@@ -129,13 +129,13 @@ rb_encoding * rb_enc_find(const char *name);
 #define rb_enc_mbmaxlen(enc) (enc)->max_enc_len
 
 /* -> mbclen (no error notification: 0 < ret <= e-p, no exception) */
-int rb_enc_mbclen(const char *p, const char *e, const rb_encoding *enc);
+int rb_enc_mbclen(const char *p, const char *e, rb_encoding *enc);
 
 /* -> mbclen (only for valid encoding) */
-int rb_enc_fast_mbclen(const char *p, const char *e, const rb_encoding *enc);
+int rb_enc_fast_mbclen(const char *p, const char *e, rb_encoding *enc);
 
 /* -> chlen, invalid or needmore */
-int rb_enc_precise_mbclen(const char *p, const char *e, const rb_encoding *enc);
+int rb_enc_precise_mbclen(const char *p, const char *e, rb_encoding *enc);
 #define MBCLEN_CHARFOUND_P(ret)     ONIGENC_MBCLEN_CHARFOUND_P(ret)
 #define MBCLEN_CHARFOUND_LEN(ret)     ONIGENC_MBCLEN_CHARFOUND_LEN(ret)
 #define MBCLEN_INVALID_P(ret)       ONIGENC_MBCLEN_INVALID_P(ret)
@@ -143,22 +143,22 @@ int rb_enc_precise_mbclen(const char *p, const char *e, const rb_encoding *enc);
 #define MBCLEN_NEEDMORE_LEN(ret)      ONIGENC_MBCLEN_NEEDMORE_LEN(ret)
 
 /* -> 0x00..0x7f, -1 */
-int rb_enc_ascget(const char *p, const char *e, int *len, const rb_encoding *enc);
+int rb_enc_ascget(const char *p, const char *e, int *len, rb_encoding *enc);
 
 
 /* -> code (and len) or raise exception */
-unsigned int rb_enc_codepoint_len(const char *p, const char *e, int *len, const rb_encoding *enc);
+unsigned int rb_enc_codepoint_len(const char *p, const char *e, int *len, rb_encoding *enc);
 
 /* prototype for obsolete function */
-unsigned int rb_enc_codepoint(const char *p, const char *e, const rb_encoding *enc);
+unsigned int rb_enc_codepoint(const char *p, const char *e, rb_encoding *enc);
 /* overriding macro */
 #define rb_enc_codepoint(p,e,enc) rb_enc_codepoint_len((p),(e),0,(enc))
 #define rb_enc_mbc_to_codepoint(p, e, enc) ONIGENC_MBC_TO_CODE((enc),(UChar*)(p),(UChar*)(e))
 
 /* -> codelen>0 or raise exception */
-int rb_enc_codelen(int code, const rb_encoding *enc);
+int rb_enc_codelen(int code, rb_encoding *enc);
 /* -> 0 for invalid codepoint */
-int rb_enc_code_to_mbclen(int code, const rb_encoding *enc);
+int rb_enc_code_to_mbclen(int code, rb_encoding *enc);
 #define rb_enc_code_to_mbclen(c, enc) ONIGENC_CODE_TO_MBCLEN((enc), (c));
 
 /* code,ptr,encoding -> write buf */
@@ -187,19 +187,19 @@ int rb_enc_code_to_mbclen(int code, const rb_encoding *enc);
 
 #define rb_enc_asciicompat(enc) (rb_enc_mbminlen(enc)==1 && !rb_enc_dummy_p(enc))
 
-int rb_enc_casefold(char *to, const char *p, const char *e, const rb_encoding *enc);
-int rb_enc_toupper(int c, const rb_encoding *enc);
-int rb_enc_tolower(int c, const rb_encoding *enc);
-ID rb_intern3(const char*, long, const rb_encoding*);
-ID rb_interned_id_p(const char *, long, const rb_encoding *);
-int rb_enc_symname_p(const char*, const rb_encoding*);
-int rb_enc_symname2_p(const char*, long, const rb_encoding*);
+int rb_enc_casefold(char *to, const char *p, const char *e, rb_encoding *enc);
+int rb_enc_toupper(int c, rb_encoding *enc);
+int rb_enc_tolower(int c, rb_encoding *enc);
+ID rb_intern3(const char*, long, rb_encoding*);
+ID rb_interned_id_p(const char *, long, rb_encoding *);
+int rb_enc_symname_p(const char*, rb_encoding*);
+int rb_enc_symname2_p(const char*, long, rb_encoding*);
 int rb_enc_str_coderange(VALUE);
-long rb_str_coderange_scan_restartable(const char*, const char*, const rb_encoding*, int*);
+long rb_str_coderange_scan_restartable(const char*, const char*, rb_encoding*, int*);
 int rb_enc_str_asciionly_p(VALUE);
 #define rb_enc_str_asciicompat_p(str) rb_enc_asciicompat(rb_enc_get(str))
-VALUE rb_enc_from_encoding(const rb_encoding *enc);
-int rb_enc_unicode_p(const rb_encoding *enc);
+VALUE rb_enc_from_encoding(rb_encoding *enc);
+int rb_enc_unicode_p(rb_encoding *enc);
 rb_encoding *rb_ascii8bit_encoding(void);
 rb_encoding *rb_utf8_encoding(void);
 rb_encoding *rb_usascii_encoding(void);
@@ -223,14 +223,14 @@ VALUE rb_enc_default_internal(void);
 void rb_enc_set_default_external(VALUE encoding);
 void rb_enc_set_default_internal(VALUE encoding);
 VALUE rb_locale_charmap(VALUE klass);
-long rb_memsearch(const void*,long,const void*,long,const rb_encoding*);
-char *rb_enc_path_next(const char *,const char *,const rb_encoding*);
-char *rb_enc_path_skip_prefix(const char *,const char *,const rb_encoding*);
-char *rb_enc_path_last_separator(const char *,const char *,const rb_encoding*);
-char *rb_enc_path_end(const char *,const char *,const rb_encoding*);
-const char *ruby_enc_find_basename(const char *name, long *baselen, long *alllen, const rb_encoding *enc);
-const char *ruby_enc_find_extname(const char *name, long *len, const rb_encoding *enc);
-ID rb_check_id_cstr(const char *ptr, long len, const rb_encoding *enc);
+long rb_memsearch(const void*,long,const void*,long,rb_encoding*);
+char *rb_enc_path_next(const char *,const char *,rb_encoding*);
+char *rb_enc_path_skip_prefix(const char *,const char *,rb_encoding*);
+char *rb_enc_path_last_separator(const char *,const char *,rb_encoding*);
+char *rb_enc_path_end(const char *,const char *,rb_encoding*);
+const char *ruby_enc_find_basename(const char *name, long *baselen, long *alllen, rb_encoding *enc);
+const char *ruby_enc_find_extname(const char *name, long *len, rb_encoding *enc);
+ID rb_check_id_cstr(const char *ptr, long len, rb_encoding *enc);
 
 RUBY_EXTERN VALUE rb_cEncoding;
 #define ENC_DUMMY_FLAG (1<<24)
@@ -242,7 +242,7 @@ RUBY_EXTERN VALUE rb_cEncoding;
 #define ENC_SET_DUMMY(enc) ((enc)->ruby_encoding_index |= ENC_DUMMY_FLAG)
 
 static inline int
-rb_enc_dummy_p(const rb_encoding *enc)
+rb_enc_dummy_p(rb_encoding *enc)
 {
     return ENC_DUMMY_P(enc) != 0;
 }
diff --git a/internal.h b/internal.h
index a02b5550ab..2c1c6a3dfc 100644
--- a/internal.h
+++ b/internal.h
@@ -769,7 +769,7 @@ VALUE rb_str_dynamic_intern(VALUE);
 ID rb_check_id_without_pindown(VALUE *);
 ID rb_sym2id_without_pindown(VALUE);
 #ifdef RUBY_ENCODING_H
-ID rb_check_id_cstr_without_pindown(const char *, long, const rb_encoding *);
+ID rb_check_id_cstr_without_pindown(const char *, long, rb_encoding *);
 #endif
 ID rb_id_attrget(ID id);
 
@@ -867,7 +867,7 @@ VALUE rb_id_quote_unprintable(ID);
 void rb_str_fill_terminator(VALUE str, const int termlen);
 VALUE rb_str_locktmp_ensure(VALUE str, VALUE (*func)(VALUE), VALUE arg);
 #ifdef RUBY_ENCODING_H
-VALUE rb_external_str_with_enc(VALUE str, const rb_encoding *eenc);
+VALUE rb_external_str_with_enc(VALUE str, rb_encoding *eenc);
 #endif
 #define STR_NOEMBED      FL_USER1
 #define STR_SHARED       FL_USER2 /* = ELTS_SHARED */
diff --git a/numeric.c b/numeric.c
index 520b7a56c7..34abd1d90c 100644
--- a/numeric.c
+++ b/numeric.c
@@ -2626,7 +2626,7 @@ rb_int_pred(VALUE num)
 #define int_pred rb_int_pred
 
 VALUE
-rb_enc_uint_chr(unsigned int code, const rb_encoding *enc)
+rb_enc_uint_chr(unsigned int code, rb_encoding *enc)
 {
     int n;
     VALUE str;
diff --git a/parse.y b/parse.y
index 7ecf367ba3..580088eeab 100644
--- a/parse.y
+++ b/parse.y
@@ -304,7 +304,7 @@ struct parser_params {
 #ifdef RIPPER
 #define intern_cstr_without_pindown(n,l,en) rb_intern3(n,l,en)
 #else
-static ID intern_cstr_without_pindown(const char *, long, const rb_encoding *);
+static ID intern_cstr_without_pindown(const char *, long, rb_encoding *);
 #endif
 
 #define STR_NEW(p,n) rb_enc_str_new((p),(n),current_enc)
@@ -675,7 +675,7 @@ static void ripper_compile_error(struct parser_params*, const char *fmt, ...);
 #else
 # define rb_compile_error rb_compile_error_with_enc
 # define compile_error parser->nerr++,rb_compile_error_with_enc
-# define PARSER_ARG ruby_sourcefile, ruby_sourceline, current_enc,
+# define PARSER_ARG ruby_sourcefile, ruby_sourceline, (void *)current_enc,
 #endif
 
 /* Older versions of Yacc set YYMAXDEPTH to a very low value by default (150,
@@ -10258,7 +10258,7 @@ id_type(ID id)
 
 #ifndef RIPPER
 static int
-is_special_global_name(const char *m, const char *e, const rb_encoding *enc)
+is_special_global_name(const char *m, const char *e, rb_encoding *enc)
 {
     int mb = 0;
 
@@ -10290,7 +10290,7 @@ rb_symname_p(const char *name)
 }
 
 int
-rb_enc_symname_p(const char *name, const rb_encoding *enc)
+rb_enc_symname_p(const char *name, rb_encoding *enc)
 {
     return rb_enc_symname2_p(name, strlen(name), enc);
 }
@@ -10299,7 +10299,7 @@ rb_enc_symname_p(const char *name, const rb_encoding *enc)
 #define IDSET_ATTRSET_FOR_INTERN (~(~0U<<(1<<ID_SCOPE_SHIFT)) & ~(1U<<ID_ATTRSET))
 
 static int
-rb_enc_symname_type(const char *name, long len, const rb_encoding *enc, unsigned int allowed_attrset)
+rb_enc_symname_type(const char *name, long len, rb_encoding *enc, unsigned int allowed_attrset)
 {
     const char *m = name;
     const char *e = m + len;
@@ -10397,7 +10397,7 @@ rb_enc_symname_type(const char *name, long len, const rb_encoding *enc, unsigned
 }
 
 int
-rb_enc_symname2_p(const char *name, long len, const rb_encoding *enc)
+rb_enc_symname2_p(const char *name, long len, rb_encoding *enc)
 {
     return rb_enc_symname_type(name, len, enc, IDSET_ATTRSET_FOR_SYNTAX) != -1;
 }
@@ -10507,7 +10507,7 @@ lookup_sym_id(st_data_t str, st_data_t *data)
 }
 
 static ID
-intern_cstr_without_pindown(const char *name, long len, const rb_encoding *enc)
+intern_cstr_without_pindown(const char *name, long len, rb_encoding *enc)
 {
     st_data_t data;
     struct RString fake_str;
@@ -10523,7 +10523,7 @@ intern_cstr_without_pindown(const char *name, long len, const rb_encoding *enc)
 }
 
 ID
-rb_intern3(const char *name, long len, const rb_encoding *enc)
+rb_intern3(const char *name, long len, rb_encoding *enc)
 {
     ID id;
 
@@ -11013,7 +11013,7 @@ rb_check_id(volatile VALUE *namep)
 }
 
 ID
-rb_check_id_cstr(const char *ptr, long len, const rb_encoding *enc)
+rb_check_id_cstr(const char *ptr, long len, rb_encoding *enc)
 {
     ID id;
 
@@ -11080,7 +11080,7 @@ attrsetname_to_attr(VALUE name)
 }
 
 ID
-rb_check_id_cstr_without_pindown(const char *ptr, long len, const rb_encoding *enc)
+rb_check_id_cstr_without_pindown(const char *ptr, long len, rb_encoding *enc)
 {
     st_data_t id;
     struct RString fake_str;
diff --git a/re.c b/re.c
index d2f5ca7cae..89910f67b4 100644
--- a/re.c
+++ b/re.c
@@ -224,7 +224,7 @@ rb_memsearch_qs_utf8(const unsigned char *xs, long m, const unsigned char *ys, l
 }
 
 long
-rb_memsearch(const void *x0, long m, const void *y0, long n, const rb_encoding *enc)
+rb_memsearch(const void *x0, long m, const void *y0, long n, rb_encoding *enc)
 {
     const unsigned char *x = x0, *y = y0;
 
@@ -333,7 +333,7 @@ rb_reg_check(VALUE re)
 
 static void
 rb_reg_expr_str(VALUE str, const char *s, long len,
-	const rb_encoding *enc, rb_encoding *resenc)
+	rb_encoding *enc, rb_encoding *resenc)
 {
     const char *p, *pend;
     int cr = ENC_CODERANGE_UNKNOWN;
@@ -636,7 +636,7 @@ rb_reg_raise(const char *s, long len, const char *err, VALUE re)
 }
 
 static VALUE
-rb_enc_reg_error_desc(const char *s, long len, const rb_encoding *enc, int options, const char *err)
+rb_enc_reg_error_desc(const char *s, long len, rb_encoding *enc, int options, const char *err)
 {
     char opts[6];
     VALUE desc = rb_str_buf_new2(err);
@@ -653,7 +653,7 @@ rb_enc_reg_error_desc(const char *s, long len, const rb_encoding *enc, int optio
 }
 
 static void
-rb_enc_reg_raise(const char *s, long len, const rb_encoding *enc, int options, const char *err)
+rb_enc_reg_raise(const char *s, long len, rb_encoding *enc, int options, const char *err)
 {
     rb_exc_raise(rb_enc_reg_error_desc(s, len, enc, options, err));
 }
@@ -826,7 +826,7 @@ onig_new_with_source(regex_t** reg, const UChar* pattern, const UChar* pattern_e
 }
 
 static Regexp*
-make_regexp(const char *s, long len, const rb_encoding *enc, int flags, onig_errmsg_buffer err,
+make_regexp(const char *s, long len, rb_encoding *enc, int flags, onig_errmsg_buffer err,
 	const char *sourcefile, int sourceline)
 {
     Regexp *rp;
@@ -1288,8 +1288,8 @@ rb_reg_fixed_encoding_p(VALUE re)
 }
 
 static VALUE
-rb_reg_preprocess(const char *p, const char *end, const rb_encoding *enc,
-        const rb_encoding **fixed_enc, onig_errmsg_buffer err);
+rb_reg_preprocess(const char *p, const char *end, rb_encoding *enc,
+        rb_encoding **fixed_enc, onig_errmsg_buffer err);
 
 
 static void
@@ -1301,10 +1301,10 @@ reg_enc_error(VALUE re, VALUE str)
 	     rb_enc_name(rb_enc_get(str)));
 }
 
-static const rb_encoding*
+static rb_encoding*
 rb_reg_prepare_enc(VALUE re, VALUE str, int warn)
 {
-    const rb_encoding *enc = 0;
+    rb_encoding *enc = 0;
 
     if (rb_enc_str_coderange(str) == ENC_CODERANGE_BROKEN) {
         rb_raise(rb_eArgError,
@@ -1345,8 +1345,8 @@ rb_reg_prepare_re(VALUE re, VALUE str)
     OnigErrorInfo einfo;
     const char *pattern;
     VALUE unescaped;
-    const rb_encoding *fixed_enc = 0;
-    const rb_encoding *enc = rb_reg_prepare_enc(re, str, 1);
+    rb_encoding *fixed_enc = 0;
+    rb_encoding *enc = rb_reg_prepare_enc(re, str, 1);
 
     if (reg->enc == enc) return reg;
 
@@ -1379,7 +1379,7 @@ long
 rb_reg_adjust_startpos(VALUE re, VALUE str, long pos, int reverse)
 {
     long range;
-    const rb_encoding *enc;
+    rb_encoding *enc;
     UChar *p, *string;
 
     enc = rb_reg_prepare_enc(re, str, 0);
@@ -2087,8 +2087,8 @@ again:
 }
 
 static int
-unescape_escaped_nonascii(const char **pp, const char *end, const rb_encoding *enc,
-        VALUE buf, const rb_encoding **encp, onig_errmsg_buffer err)
+unescape_escaped_nonascii(const char **pp, const char *end, rb_encoding *enc,
+        VALUE buf, rb_encoding **encp, onig_errmsg_buffer err)
 {
     const char *p = *pp;
     int chmaxlen = rb_enc_mbmaxlen(enc);
@@ -2151,7 +2151,7 @@ check_unicode_range(unsigned long code, onig_errmsg_buffer err)
 
 static int
 append_utf8(unsigned long uv,
-        VALUE buf, const rb_encoding **encp, onig_errmsg_buffer err)
+        VALUE buf, rb_encoding **encp, onig_errmsg_buffer err)
 {
     if (check_unicode_range(uv, err) != 0)
         return -1;
@@ -2178,7 +2178,7 @@ append_utf8(unsigned long uv,
 
 static int
 unescape_unicode_list(const char **pp, const char *end,
-        VALUE buf, const rb_encoding **encp, onig_errmsg_buffer err)
+        VALUE buf, rb_encoding **encp, onig_errmsg_buffer err)
 {
     const char *p = *pp;
     int has_unicode = 0;
@@ -2215,7 +2215,7 @@ unescape_unicode_list(const char **pp, const char *end,
 
 static int
 unescape_unicode_bmp(const char **pp, const char *end,
-        VALUE buf, const rb_encoding **encp, onig_errmsg_buffer err)
+        VALUE buf, rb_encoding **encp, onig_errmsg_buffer err)
 {
     const char *p = *pp;
     size_t len;
@@ -2237,8 +2237,8 @@ unescape_unicode_bmp(const char **pp, const char *end,
 }
 
 static int
-unescape_nonascii(const char *p, const char *end, const rb_encoding *enc,
-        VALUE buf, const rb_encoding **encp, int *has_property,
+unescape_nonascii(const char *p, const char *end, rb_encoding *enc,
+        VALUE buf, rb_encoding **encp, int *has_property,
         onig_errmsg_buffer err)
 {
     char c;
@@ -2343,8 +2343,8 @@ escape_asis:
 }
 
 static VALUE
-rb_reg_preprocess(const char *p, const char *end, const rb_encoding *enc,
-        const rb_encoding **fixed_enc, onig_errmsg_buffer err)
+rb_reg_preprocess(const char *p, const char *end, rb_encoding *enc,
+        rb_encoding **fixed_enc, onig_errmsg_buffer err)
 {
     VALUE buf;
     int has_property = 0;
@@ -2375,11 +2375,11 @@ rb_reg_preprocess(const char *p, const char *end, const rb_encoding *enc,
 VALUE
 rb_reg_check_preprocess(VALUE str)
 {
-    const rb_encoding *fixed_enc = 0;
+    rb_encoding *fixed_enc = 0;
     onig_errmsg_buffer err = "";
     VALUE buf;
     char *p, *end;
-    const rb_encoding *enc;
+    rb_encoding *enc;
 
     StringValue(str);
     p = RSTRING_PTR(str);
@@ -2398,12 +2398,12 @@ rb_reg_check_preprocess(VALUE str)
 static VALUE
 rb_reg_preprocess_dregexp(VALUE ary, int options)
 {
-    const rb_encoding *fixed_enc = 0;
-    const rb_encoding *regexp_enc = 0;
+    rb_encoding *fixed_enc = 0;
+    rb_encoding *regexp_enc = 0;
     onig_errmsg_buffer err = "";
     int i;
     VALUE result = 0;
-    const rb_encoding *ascii8bit = rb_ascii8bit_encoding();
+    rb_encoding *ascii8bit = rb_ascii8bit_encoding();
 
     if (RARRAY_LEN(ary) == 0) {
         rb_raise(rb_eArgError, "no arguments given");
@@ -2413,7 +2413,7 @@ rb_reg_preprocess_dregexp(VALUE ary, int options)
         VALUE str = RARRAY_AREF(ary, i);
         VALUE buf;
         char *p, *end;
-        const rb_encoding *src_enc;
+        rb_encoding *src_enc;
 
 	src_enc = rb_enc_get(str);
 	if (options & ARG_ENCODING_NONE &&
@@ -2454,14 +2454,14 @@ rb_reg_preprocess_dregexp(VALUE ary, int options)
 }
 
 static int
-rb_reg_initialize(VALUE obj, const char *s, long len, const rb_encoding *enc,
+rb_reg_initialize(VALUE obj, const char *s, long len, rb_encoding *enc,
 		  int options, onig_errmsg_buffer err,
 		  const char *sourcefile, int sourceline)
 {
     struct RRegexp *re = RREGEXP(obj);
     VALUE unescaped;
-    const rb_encoding *fixed_enc = 0;
-    const rb_encoding *a_enc = rb_ascii8bit_encoding();
+    rb_encoding *fixed_enc = 0;
+    rb_encoding *a_enc = rb_ascii8bit_encoding();
 
     rb_check_frozen(obj);
     if (FL_TEST(obj, REG_LITERAL))
@@ -2577,7 +2577,7 @@ rb_reg_new_ary(VALUE ary, int opt)
 }
 
 VALUE
-rb_enc_reg_new(const char *s, long len, const rb_encoding *enc, int options)
+rb_enc_reg_new(const char *s, long len, rb_encoding *enc, int options)
 {
     VALUE re = rb_reg_alloc();
     onig_errmsg_buffer err = "";
diff --git a/sprintf.c b/sprintf.c
index a4c1a6d9e6..52a7168dc9 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -1192,7 +1192,7 @@ ruby__sfvextra(rb_printf_buffer *fp, size_t valsize, void *valp, long *sz, int s
 }
 
 VALUE
-rb_enc_vsprintf(const rb_encoding *enc, const char *fmt, va_list ap)
+rb_enc_vsprintf(rb_encoding *enc, const char *fmt, va_list ap)
 {
     rb_printf_buffer_extra buffer;
 #define f buffer.base
@@ -1225,7 +1225,7 @@ rb_enc_vsprintf(const rb_encoding *enc, const char *fmt, va_list ap)
 }
 
 VALUE
-rb_enc_sprintf(const rb_encoding *enc, const char *format, ...)
+rb_enc_sprintf(rb_encoding *enc, const char *format, ...)
 {
     VALUE result;
     va_list ap;
diff --git a/string.c b/string.c
index fa9dae1766..15e6bcd623 100644
--- a/string.c
+++ b/string.c
@@ -333,7 +333,7 @@ coderange_scan(const char *p, long len, rb_encoding *enc)
 }
 
 long
-rb_str_coderange_scan_restartable(const char *s, const char *e, const rb_encoding *enc, int *cr)
+rb_str_coderange_scan_restartable(const char *s, const char *e, rb_encoding *enc, int *cr)
 {
     const char *p = s;
 
@@ -544,7 +544,7 @@ rb_usascii_str_new(const char *ptr, long len)
 }
 
 VALUE
-rb_enc_str_new(const char *ptr, long len, const rb_encoding *enc)
+rb_enc_str_new(const char *ptr, long len, rb_encoding *enc)
 {
     VALUE str;
 
@@ -571,7 +571,7 @@ rb_usascii_str_new_cstr(const char *ptr)
 }
 
 VALUE
-rb_enc_str_new_cstr(const char *ptr, const rb_encoding *enc)
+rb_enc_str_new_cstr(const char *ptr, rb_encoding *enc)
 {
     must_not_null(ptr);
     if (rb_enc_mbminlen(enc) != 1) {
@@ -599,7 +599,7 @@ rb_tainted_str_new_cstr(const char *ptr)
 }
 
 VALUE
-rb_str_conv_enc_opts(VALUE str, const rb_encoding *from, const rb_encoding *to, int ecflags, VALUE ecopts)
+rb_str_conv_enc_opts(VALUE str, rb_encoding *from, rb_encoding *to, int ecflags, VALUE ecopts)
 {
     extern VALUE rb_cEncodingConverter;
     rb_econv_t *ec;
@@ -672,13 +672,13 @@ rb_str_conv_enc_opts(VALUE str, const rb_encoding *from, const rb_encoding *to,
 }
 
 VALUE
-rb_str_conv_enc(VALUE str, const rb_encoding *from, const rb_encoding *to)
+rb_str_conv_enc(VALUE str, rb_encoding *from, rb_encoding *to)
 {
     return rb_str_conv_enc_opts(str, from, to, 0, Qnil);
 }
 
 VALUE
-rb_external_str_new_with_enc(const char *ptr, long len, const rb_encoding *eenc)
+rb_external_str_new_with_enc(const char *ptr, long len, rb_encoding *eenc)
 {
     VALUE str;
 
@@ -687,7 +687,7 @@ rb_external_str_new_with_enc(const char *ptr, long len, const rb_encoding *eenc)
 }
 
 VALUE
-rb_external_str_with_enc(VALUE str, const rb_encoding *eenc)
+rb_external_str_with_enc(VALUE str, rb_encoding *eenc)
 {
     if (eenc == rb_usascii_encoding() &&
 	rb_enc_str_coderange(str) != ENC_CODERANGE_7BIT) {
@@ -747,7 +747,7 @@ rb_str_export_locale(VALUE str)
 }
 
 VALUE
-rb_str_export_to_enc(VALUE str, const rb_encoding *enc)
+rb_str_export_to_enc(VALUE str, rb_encoding *enc)
 {
     return rb_str_conv_enc(str, STR_ENC_GET(str), enc);
 }
@@ -1097,7 +1097,7 @@ count_utf8_lead_bytes_with_word(const uintptr_t *s)
 #endif
 
 static inline long
-enc_strlen(const char *p, const char *e, const rb_encoding *enc, int cr)
+enc_strlen(const char *p, const char *e, rb_encoding *enc, int cr)
 {
     long c;
     const char *q;
@@ -1168,7 +1168,7 @@ enc_strlen(const char *p, const char *e, const rb_encoding *enc, int cr)
 }
 
 long
-rb_enc_strlen(const char *p, const char *e, const rb_encoding *enc)
+rb_enc_strlen(const char *p, const char *e, rb_encoding *enc)
 {
     return enc_strlen(p, e, enc, ENC_CODERANGE_UNKNOWN);
 }
@@ -1635,7 +1635,7 @@ rb_str_s_try_convert(VALUE dummy, VALUE str)
 }
 
 static char*
-str_nth_len(const char *p, const char *e, long *nthp, const rb_encoding *enc)
+str_nth_len(const char *p, const char *e, long *nthp, rb_encoding *enc)
 {
     long nth = *nthp;
     if (rb_enc_mbmaxlen(enc) == 1) {
@@ -1685,7 +1685,7 @@ str_nth_len(const char *p, const char *e, long *nthp, const rb_encoding *enc)
 }
 
 char*
-rb_enc_nth(const char *p, const char *e, long nth, const rb_encoding *enc)
+rb_enc_nth(const char *p, const char *e, long nth, rb_encoding *enc)
 {
     return str_nth_len(p, e, &nth, enc);
 }
@@ -2152,7 +2152,7 @@ rb_enc_cr_str_buf_cat(VALUE str, const char *ptr, long len,
 }
 
 VALUE
-rb_enc_str_buf_cat(VALUE str, const char *ptr, long len, const rb_encoding *ptr_enc)
+rb_enc_str_buf_cat(VALUE str, const char *ptr, long len, rb_encoding *ptr_enc)
 {
     return rb_enc_cr_str_buf_cat(str, ptr, len,
         rb_enc_to_index(ptr_enc), ENC_CODERANGE_UNKNOWN, NULL);