sed -i s/RUBY3/RBIMPL/g

Devs do not love "3".  The only exception is RUBY3_KEYWORDS in parse.y,
which seems unrelated to our interests.

8 files changed, 209 insertions, 209 deletions

diff --git a/include/ruby/impl/has/attribute.h b/include/ruby/impl/has/attribute.h
index b24d1effd2..f4185b4b93 100644
--- a/include/ruby/impl/has/attribute.h
+++ b/include/ruby/impl/has/attribute.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_ATTRIBUTE_H                        /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_ATTRIBUTE_H
+#ifndef RBIMPL_HAS_ATTRIBUTE_H                       /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_ATTRIBUTE_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,147 +18,147 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_ATTRIBUTE.
+ * @brief      Defines #RBIMPL_HAS_ATTRIBUTE.
  */
 #include "ruby/impl/config.h"
 #include "ruby/impl/compiler_since.h"
 #include "ruby/impl/token_paste.h"
 
 #if defined(__has_attribute)
-# if __has_attribute(pure) || RUBY3_COMPILER_IS(GCC)
+# if __has_attribute(pure) || RBIMPL_COMPILER_IS(GCC)
 #  /* FreeBSD's   <sys/cdefs.h>   defines   its   own   *broken*   version   of
 #   * __has_attribute.   Cygwin copied  that  content  to be  a  victim of  the
 #   * broken-ness.  We don't take them into account. */
-#  define RUBY3_HAVE___HAS_ATTRIBUTE 1
+#  define RBIMPL_HAVE___HAS_ATTRIBUTE 1
 # endif
 #endif
 
 /** Wraps (or simulates) `__has_attribute`. */
-#if defined(RUBY3_HAVE___HAS_ATTRIBUTE)
-# define RUBY3_HAS_ATTRIBUTE(_) __has_attribute(_)
+#if defined(RBIMPL_HAVE___HAS_ATTRIBUTE)
+# define RBIMPL_HAS_ATTRIBUTE(_) __has_attribute(_)
 
-#elif RUBY3_COMPILER_IS(GCC)
+#elif RBIMPL_COMPILER_IS(GCC)
 # /* GCC  <= 4  lack __has_attribute  predefined macro,  while have  attributes
 #  * themselves.  We can simulate the macro like the following: */
-# define RUBY3_HAS_ATTRIBUTE(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_ATTRIBUTE_, _)
-# define RUBY3_HAS_ATTRIBUTE_aligned                    RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_alloc_size                 RUBY3_COMPILER_SINCE(GCC, 4, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_artificial                 RUBY3_COMPILER_SINCE(GCC, 4, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_always_inline              RUBY3_COMPILER_SINCE(GCC, 3, 1, 0)
-# define RUBY3_HAS_ATTRIBUTE_cdecl                      RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_cold                       RUBY3_COMPILER_SINCE(GCC, 4, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_const                      RUBY3_COMPILER_SINCE(GCC, 2, 6, 0)
-# define RUBY3_HAS_ATTRIBUTE_deprecated                 RUBY3_COMPILER_SINCE(GCC, 3, 1, 0)
-# define RUBY3_HAS_ATTRIBUTE_dllexport                  RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_dllimport                  RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_error                      RUBY3_COMPILER_SINCE(GCC, 4, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_format                     RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_hot                        RUBY3_COMPILER_SINCE(GCC, 4, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_leaf                       RUBY3_COMPILER_SINCE(GCC, 4, 6, 0)
-# define RUBY3_HAS_ATTRIBUTE_malloc                     RUBY3_COMPILER_SINCE(GCC, 3, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_no_address_safety_analysis RUBY3_COMPILER_SINCE(GCC, 4, 8, 0)
-# define RUBY3_HAS_ATTRIBUTE_no_sanitize_address        RUBY3_COMPILER_SINCE(GCC, 4, 8, 0)
-# define RUBY3_HAS_ATTRIBUTE_no_sanitize_undefined      RUBY3_COMPILER_SINCE(GCC, 4, 9, 0)
-# define RUBY3_HAS_ATTRIBUTE_noinline                   RUBY3_COMPILER_SINCE(GCC, 3, 1, 0)
-# define RUBY3_HAS_ATTRIBUTE_nonnull                    RUBY3_COMPILER_SINCE(GCC, 3, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_noreturn                   RUBY3_COMPILER_SINCE(GCC, 2, 5, 0)
-# define RUBY3_HAS_ATTRIBUTE_nothrow                    RUBY3_COMPILER_SINCE(GCC, 3, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_pure                       RUBY3_COMPILER_SINCE(GCC, 2,96, 0)
-# define RUBY3_HAS_ATTRIBUTE_returns_nonnull            RUBY3_COMPILER_SINCE(GCC, 4, 9, 0)
-# define RUBY3_HAS_ATTRIBUTE_returns_twice              RUBY3_COMPILER_SINCE(GCC, 4, 1, 0)
-# define RUBY3_HAS_ATTRIBUTE_stdcall                    RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_unused                     RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_ATTRIBUTE_visibility                 RUBY3_COMPILER_SINCE(GCC, 3, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_warn_unused_result         RUBY3_COMPILER_SINCE(GCC, 3, 4, 0)
-# define RUBY3_HAS_ATTRIBUTE_warning                    RUBY3_COMPILER_SINCE(GCC, 4, 3, 0)
-# define RUBY3_HAS_ATTRIBUTE_weak                       RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_ATTRIBUTE_, _)
+# define RBIMPL_HAS_ATTRIBUTE_aligned                    RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_alloc_size                 RBIMPL_COMPILER_SINCE(GCC, 4, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_artificial                 RBIMPL_COMPILER_SINCE(GCC, 4, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_always_inline              RBIMPL_COMPILER_SINCE(GCC, 3, 1, 0)
+# define RBIMPL_HAS_ATTRIBUTE_cdecl                      RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_cold                       RBIMPL_COMPILER_SINCE(GCC, 4, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_const                      RBIMPL_COMPILER_SINCE(GCC, 2, 6, 0)
+# define RBIMPL_HAS_ATTRIBUTE_deprecated                 RBIMPL_COMPILER_SINCE(GCC, 3, 1, 0)
+# define RBIMPL_HAS_ATTRIBUTE_dllexport                  RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_dllimport                  RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_error                      RBIMPL_COMPILER_SINCE(GCC, 4, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_format                     RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_hot                        RBIMPL_COMPILER_SINCE(GCC, 4, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_leaf                       RBIMPL_COMPILER_SINCE(GCC, 4, 6, 0)
+# define RBIMPL_HAS_ATTRIBUTE_malloc                     RBIMPL_COMPILER_SINCE(GCC, 3, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_no_address_safety_analysis RBIMPL_COMPILER_SINCE(GCC, 4, 8, 0)
+# define RBIMPL_HAS_ATTRIBUTE_no_sanitize_address        RBIMPL_COMPILER_SINCE(GCC, 4, 8, 0)
+# define RBIMPL_HAS_ATTRIBUTE_no_sanitize_undefined      RBIMPL_COMPILER_SINCE(GCC, 4, 9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_noinline                   RBIMPL_COMPILER_SINCE(GCC, 3, 1, 0)
+# define RBIMPL_HAS_ATTRIBUTE_nonnull                    RBIMPL_COMPILER_SINCE(GCC, 3, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_noreturn                   RBIMPL_COMPILER_SINCE(GCC, 2, 5, 0)
+# define RBIMPL_HAS_ATTRIBUTE_nothrow                    RBIMPL_COMPILER_SINCE(GCC, 3, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_pure                       RBIMPL_COMPILER_SINCE(GCC, 2,96, 0)
+# define RBIMPL_HAS_ATTRIBUTE_returns_nonnull            RBIMPL_COMPILER_SINCE(GCC, 4, 9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_returns_twice              RBIMPL_COMPILER_SINCE(GCC, 4, 1, 0)
+# define RBIMPL_HAS_ATTRIBUTE_stdcall                    RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_unused                     RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_ATTRIBUTE_visibility                 RBIMPL_COMPILER_SINCE(GCC, 3, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_warn_unused_result         RBIMPL_COMPILER_SINCE(GCC, 3, 4, 0)
+# define RBIMPL_HAS_ATTRIBUTE_warning                    RBIMPL_COMPILER_SINCE(GCC, 4, 3, 0)
+# define RBIMPL_HAS_ATTRIBUTE_weak                       RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
 # /* Note that "0, 0, 0" might be inaccurate. */
 
-#elif RUBY3_COMPILER_IS(SunPro)
+#elif RBIMPL_COMPILER_IS(SunPro)
 # /* Oracle Solaris Studio 12.4 (cc version 5.11) introduced __has_attribute.
 #  * Before that, following attributes were available. */
 # /* See https://docs.oracle.com/cd/F24633_01/index.html */
-# define RUBY3_HAS_ATTRIBUTE(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_ATTRIBUTE_, _)
-# define RUBY3_HAS_ATTRIBUTE_alias                      RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_aligned                    RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_always_inline              RUBY3_COMPILER_SINCE(SunPro, 5, 10, 0)
-# define RUBY3_HAS_ATTRIBUTE_const                      RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_constructor                RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_destructor                 RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_malloc                     RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_noinline                   RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_noreturn                   RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_packed                     RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_pure                       RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_returns_twice              RUBY3_COMPILER_SINCE(SunPro, 5, 10, 0)
-# define RUBY3_HAS_ATTRIBUTE_vector_size                RUBY3_COMPILER_SINCE(SunPro, 5, 10, 0)
-# define RUBY3_HAS_ATTRIBUTE_visibility                 RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
-# define RUBY3_HAS_ATTRIBUTE_weak                       RUBY3_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_ATTRIBUTE_, _)
+# define RBIMPL_HAS_ATTRIBUTE_alias                      RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_aligned                    RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_always_inline              RBIMPL_COMPILER_SINCE(SunPro, 5, 10, 0)
+# define RBIMPL_HAS_ATTRIBUTE_const                      RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_constructor                RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_destructor                 RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_malloc                     RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_noinline                   RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_noreturn                   RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_packed                     RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_pure                       RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_returns_twice              RBIMPL_COMPILER_SINCE(SunPro, 5, 10, 0)
+# define RBIMPL_HAS_ATTRIBUTE_vector_size                RBIMPL_COMPILER_SINCE(SunPro, 5, 10, 0)
+# define RBIMPL_HAS_ATTRIBUTE_visibility                 RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
+# define RBIMPL_HAS_ATTRIBUTE_weak                       RBIMPL_COMPILER_SINCE(SunPro, 5,  9, 0)
 
 #elif defined (_MSC_VER)
-# define RUBY3_HAS_ATTRIBUTE(_) 0
+# define RBIMPL_HAS_ATTRIBUTE(_) 0
 # /* Fallback below doesn't work: see win32/Makefile.sub */
 
 #else
 # /* Take config.h definition when available. */
-# define RUBY3_HAS_ATTRIBUTE(_) (RUBY3_TOKEN_PASTE(RUBY3_HAS_ATTRIBUTE_, _)+0)
+# define RBIMPL_HAS_ATTRIBUTE(_) (RBIMPL_TOKEN_PASTE(RBIMPL_HAS_ATTRIBUTE_, _)+0)
 # ifdef ALWAYS_INLINE
-#  define RUBY3_HAS_ATTRIBUTE_always_inline 1
+#  define RBIMPL_HAS_ATTRIBUTE_always_inline 1
 # endif
 # ifdef FUNC_CDECL
-#  define RUBY3_HAS_ATTRIBUTE_cdecl 1
+#  define RBIMPL_HAS_ATTRIBUTE_cdecl 1
 # endif
 # ifdef CONSTFUNC
-#  define RUBY3_HAS_ATTRIBUTE_const 1
+#  define RBIMPL_HAS_ATTRIBUTE_const 1
 # endif
 # ifdef DEPRECATED
-#  define RUBY3_HAS_ATTRIBUTE_deprecated 1
+#  define RBIMPL_HAS_ATTRIBUTE_deprecated 1
 # endif
 # ifdef ERRORFUNC
-#  define RUBY3_HAS_ATTRIBUTE_error 1
+#  define RBIMPL_HAS_ATTRIBUTE_error 1
 # endif
 # ifdef FUNC_FASTCALL
-#  define RUBY3_HAS_ATTRIBUTE_fastcall 1
+#  define RBIMPL_HAS_ATTRIBUTE_fastcall 1
 # endif
 # ifdef PUREFUNC
-#  define RUBY3_HAS_ATTRIBUTE_pure 1
+#  define RBIMPL_HAS_ATTRIBUTE_pure 1
 # endif
 # ifdef NO_ADDRESS_SAFETY_ANALYSIS
-#  define RUBY3_HAS_ATTRIBUTE_no_address_safety_analysis 1
+#  define RBIMPL_HAS_ATTRIBUTE_no_address_safety_analysis 1
 # endif
 # ifdef NO_SANITIZE
-#  define RUBY3_HAS_ATTRIBUTE_no_sanitize 1
+#  define RBIMPL_HAS_ATTRIBUTE_no_sanitize 1
 # endif
 # ifdef NO_SANITIZE_ADDRESS
-#  define RUBY3_HAS_ATTRIBUTE_no_sanitize_address 1
+#  define RBIMPL_HAS_ATTRIBUTE_no_sanitize_address 1
 # endif
 # ifdef NOINLINE
-#  define RUBY3_HAS_ATTRIBUTE_noinline 1
+#  define RBIMPL_HAS_ATTRIBUTE_noinline 1
 # endif
-# ifdef RUBY3_FUNC_NONNULL
-#  define RUBY3_HAS_ATTRIBUTE_nonnull 1
+# ifdef RBIMPL_FUNC_NONNULL
+#  define RBIMPL_HAS_ATTRIBUTE_nonnull 1
 # endif
 # ifdef NORETURN
-#  define RUBY3_HAS_ATTRIBUTE_noreturn 1
+#  define RBIMPL_HAS_ATTRIBUTE_noreturn 1
 # endif
 # ifdef FUNC_OPTIMIZED
-#  define RUBY3_HAS_ATTRIBUTE_optimize 1
+#  define RBIMPL_HAS_ATTRIBUTE_optimize 1
 # endif
 # ifdef FUNC_STDCALL
-#  define RUBY3_HAS_ATTRIBUTE_stdcall 1
+#  define RBIMPL_HAS_ATTRIBUTE_stdcall 1
 # endif
 # ifdef MAYBE_UNUSED
-#  define RUBY3_HAS_ATTRIBUTE_unused 1
+#  define RBIMPL_HAS_ATTRIBUTE_unused 1
 # endif
 # ifdef WARN_UNUSED_RESULT
-#  define RUBY3_HAS_ATTRIBUTE_warn_unused_result 1
+#  define RBIMPL_HAS_ATTRIBUTE_warn_unused_result 1
 # endif
 # ifdef WARNINGFUNC
-#  define RUBY3_HAS_ATTRIBUTE_warning 1
+#  define RBIMPL_HAS_ATTRIBUTE_warning 1
 # endif
 # ifdef WEAK
-#  define RUBY3_HAS_ATTRIBUTE_weak 1
+#  define RBIMPL_HAS_ATTRIBUTE_weak 1
 # endif
 #endif
 
-#endif /* RUBY3_HAS_ATTRIBUTE_H */
+#endif /* RBIMPL_HAS_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/builtin.h b/include/ruby/impl/has/builtin.h
index 27c1c151e7..5ec7e23559 100644
--- a/include/ruby/impl/has/builtin.h
+++ b/include/ruby/impl/has/builtin.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_BUILTIN_H                          /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_BUILTIN_H
+#ifndef RBIMPL_HAS_BUILTIN_H                         /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_BUILTIN_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,88 +18,88 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_BUILTIN.
+ * @brief      Defines #RBIMPL_HAS_BUILTIN.
  */
 #include "ruby/impl/config.h"
 #include "ruby/impl/compiler_since.h"
 #include "ruby/impl/token_paste.h"
 
 #if defined(__has_builtin)
-# if RUBY3_COMPILER_IS(Intel)
+# if RBIMPL_COMPILER_IS(Intel)
 #  /* :TODO: Intel  C Compiler  has __has_builtin (since  19.1 maybe?),  and is
 #   * reportedly  broken.  We  have to  skip them.   However the  situation can
 #   * change.  They might improve someday.  We need to revisit here later. */
-# elif RUBY3_COMPILER_IS(GCC) && ! __has_builtin(__builtin_alloca)
+# elif RBIMPL_COMPILER_IS(GCC) && ! __has_builtin(__builtin_alloca)
 #  /* FreeBSD's   <sys/cdefs.h>   defines   its   own   *broken*   version   of
 #   * __has_builtin.   Cygwin  copied  that  content  to be  a  victim  of  the
 #   * broken-ness.  We don't take them into account. */
 # else
-#  define RUBY3_HAVE___HAS_BUILTIN 1
+#  define RBIMPL_HAVE___HAS_BUILTIN 1
 # endif
 #endif
 
 /** Wraps (or simulates) `__has_builtin`. */
-#if defined(RUBY3_HAVE___HAS_BUILTIN)
-# define RUBY3_HAS_BUILTIN(_) __has_builtin(_)
+#if defined(RBIMPL_HAVE___HAS_BUILTIN)
+# define RBIMPL_HAS_BUILTIN(_) __has_builtin(_)
 
-#elif RUBY3_COMPILER_IS(GCC)
+#elif RBIMPL_COMPILER_IS(GCC)
 # /* :FIXME: Historically  GCC has had  tons of builtins, but  it implemented
 #  * __has_builtin  only  since  GCC  10.   This section  can  be  made  more
 #  * granular. */
 # /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66970 */
-# define RUBY3_HAS_BUILTIN(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_BUILTIN_, _)
-# define RUBY3_HAS_BUILTIN___builtin_add_overflow      RUBY3_COMPILER_SINCE(GCC, 5, 1, 0)
-# define RUBY3_HAS_BUILTIN___builtin_alloca            RUBY3_COMPILER_SINCE(GCC, 0, 0, 0)
-# define RUBY3_HAS_BUILTIN___builtin_alloca_with_align RUBY3_COMPILER_SINCE(GCC, 6, 1, 0)
+# define RBIMPL_HAS_BUILTIN(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_BUILTIN_, _)
+# define RBIMPL_HAS_BUILTIN___builtin_add_overflow      RBIMPL_COMPILER_SINCE(GCC, 5, 1, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_alloca            RBIMPL_COMPILER_SINCE(GCC, 0, 0, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_alloca_with_align RBIMPL_COMPILER_SINCE(GCC, 6, 1, 0)
 # /* See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52624 for bswap16. */
-# define RUBY3_HAS_BUILTIN___builtin_bswap16           RUBY3_COMPILER_SINCE(GCC, 4, 8, 0)
-# define RUBY3_HAS_BUILTIN___builtin_bswap32           RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_bswap64           RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_clz               RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_clzl              RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_clzll             RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_constant_p        RUBY3_COMPILER_SINCE(GCC, 2,95, 3)
-# define RUBY3_HAS_BUILTIN___builtin_ctz               RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_ctzl              RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_ctzll             RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_expect            RUBY3_COMPILER_SINCE(GCC, 3, 0, 0)
-# define RUBY3_HAS_BUILTIN___builtin_mul_overflow      RUBY3_COMPILER_SINCE(GCC, 5, 1, 0)
-# define RUBY3_HAS_BUILTIN___builtin_mul_overflow_p    RUBY3_COMPILER_SINCE(GCC, 7, 0, 0)
-# define RUBY3_HAS_BUILTIN___builtin_popcount          RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_popcountl         RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_popcountll        RUBY3_COMPILER_SINCE(GCC, 3, 6, 0)
-# define RUBY3_HAS_BUILTIN___builtin_sub_overflow      RUBY3_COMPILER_SINCE(GCC, 5, 1, 0)
-# define RUBY3_HAS_BUILTIN___builtin_unreachable       RUBY3_COMPILER_SINCE(GCC, 4, 5, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_bswap16           RBIMPL_COMPILER_SINCE(GCC, 4, 8, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_bswap32           RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_bswap64           RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_clz               RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_clzl              RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_clzll             RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_constant_p        RBIMPL_COMPILER_SINCE(GCC, 2,95, 3)
+# define RBIMPL_HAS_BUILTIN___builtin_ctz               RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_ctzl              RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_ctzll             RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_expect            RBIMPL_COMPILER_SINCE(GCC, 3, 0, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_mul_overflow      RBIMPL_COMPILER_SINCE(GCC, 5, 1, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_mul_overflow_p    RBIMPL_COMPILER_SINCE(GCC, 7, 0, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_popcount          RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_popcountl         RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_popcountll        RBIMPL_COMPILER_SINCE(GCC, 3, 6, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_sub_overflow      RBIMPL_COMPILER_SINCE(GCC, 5, 1, 0)
+# define RBIMPL_HAS_BUILTIN___builtin_unreachable       RBIMPL_COMPILER_SINCE(GCC, 4, 5, 0)
 # /* Note that "0, 0, 0" might be inaccurate. */
 
-#elif RUBY3_COMPILER_IS(MSVC)
+#elif RBIMPL_COMPILER_IS(MSVC)
 # /* MSVC has UNREACHABLE, but that is not __builtin_unreachable. */
-# define RUBY3_HAS_BUILTIN(_) 0
+# define RBIMPL_HAS_BUILTIN(_) 0
 
 #else
 # /* Take config.h definition when available */
-# define RUBY3_HAS_BUILTIN(_) (RUBY3_TOKEN_PASTE(RUBY3_HAS_BUILTIN_, _)+0)
-# define RUBY3_HAS_BUILTIN___builtin_add_overflow      HAVE_BUILTIN___BUILTIN_ADD_OVERFLOW
-# define RUBY3_HAS_BUILTIN___builtin_alloca_with_align HAVE_BUILTIN___BUILTIN_ALLOCA_WITH_ALIGN
-# define RUBY3_HAS_BUILTIN___builtin_assume_aligned    HAVE_BUILTIN___BUILTIN_ASSUME_ALIGNED
-# define RUBY3_HAS_BUILTIN___builtin_bswap16           HAVE_BUILTIN___BUILTIN_BSWAP16
-# define RUBY3_HAS_BUILTIN___builtin_bswap32           HAVE_BUILTIN___BUILTIN_BSWAP32
-# define RUBY3_HAS_BUILTIN___builtin_bswap64           HAVE_BUILTIN___BUILTIN_BSWAP64
-# define RUBY3_HAS_BUILTIN___builtin_clz               HAVE_BUILTIN___BUILTIN_CLZ
-# define RUBY3_HAS_BUILTIN___builtin_clzl              HAVE_BUILTIN___BUILTIN_CLZL
-# define RUBY3_HAS_BUILTIN___builtin_clzll             HAVE_BUILTIN___BUILTIN_CLZLL
-# define RUBY3_HAS_BUILTIN___builtin_constant_p        HAVE_BUILTIN___BUILTIN_CONSTANT_P
-# define RUBY3_HAS_BUILTIN___builtin_ctz               HAVE_BUILTIN___BUILTIN_CTZ
-# define RUBY3_HAS_BUILTIN___builtin_ctzll             HAVE_BUILTIN___BUILTIN_CTZLL
-# define RUBY3_HAS_BUILTIN___builtin_expect            HAVE_BUILTIN___BUILTIN_EXPECT
-# define RUBY3_HAS_BUILTIN___builtin_mul_overflow      HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW
-# define RUBY3_HAS_BUILTIN___builtin_mul_overflow_p    HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW_P
-# define RUBY3_HAS_BUILTIN___builtin_popcount          HAVE_BUILTIN___BUILTIN_POPCOUNT
-# define RUBY3_HAS_BUILTIN___builtin_popcountll        HAVE_BUILTIN___BUILTIN_POPCOUNTLL
-# define RUBY3_HAS_BUILTIN___builtin_sub_overflow      HAVE_BUILTIN___BUILTIN_SUB_OVERFLOW
+# define RBIMPL_HAS_BUILTIN(_) (RBIMPL_TOKEN_PASTE(RBIMPL_HAS_BUILTIN_, _)+0)
+# define RBIMPL_HAS_BUILTIN___builtin_add_overflow      HAVE_BUILTIN___BUILTIN_ADD_OVERFLOW
+# define RBIMPL_HAS_BUILTIN___builtin_alloca_with_align HAVE_BUILTIN___BUILTIN_ALLOCA_WITH_ALIGN
+# define RBIMPL_HAS_BUILTIN___builtin_assume_aligned    HAVE_BUILTIN___BUILTIN_ASSUME_ALIGNED
+# define RBIMPL_HAS_BUILTIN___builtin_bswap16           HAVE_BUILTIN___BUILTIN_BSWAP16
+# define RBIMPL_HAS_BUILTIN___builtin_bswap32           HAVE_BUILTIN___BUILTIN_BSWAP32
+# define RBIMPL_HAS_BUILTIN___builtin_bswap64           HAVE_BUILTIN___BUILTIN_BSWAP64
+# define RBIMPL_HAS_BUILTIN___builtin_clz               HAVE_BUILTIN___BUILTIN_CLZ
+# define RBIMPL_HAS_BUILTIN___builtin_clzl              HAVE_BUILTIN___BUILTIN_CLZL
+# define RBIMPL_HAS_BUILTIN___builtin_clzll             HAVE_BUILTIN___BUILTIN_CLZLL
+# define RBIMPL_HAS_BUILTIN___builtin_constant_p        HAVE_BUILTIN___BUILTIN_CONSTANT_P
+# define RBIMPL_HAS_BUILTIN___builtin_ctz               HAVE_BUILTIN___BUILTIN_CTZ
+# define RBIMPL_HAS_BUILTIN___builtin_ctzll             HAVE_BUILTIN___BUILTIN_CTZLL
+# define RBIMPL_HAS_BUILTIN___builtin_expect            HAVE_BUILTIN___BUILTIN_EXPECT
+# define RBIMPL_HAS_BUILTIN___builtin_mul_overflow      HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW
+# define RBIMPL_HAS_BUILTIN___builtin_mul_overflow_p    HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW_P
+# define RBIMPL_HAS_BUILTIN___builtin_popcount          HAVE_BUILTIN___BUILTIN_POPCOUNT
+# define RBIMPL_HAS_BUILTIN___builtin_popcountll        HAVE_BUILTIN___BUILTIN_POPCOUNTLL
+# define RBIMPL_HAS_BUILTIN___builtin_sub_overflow      HAVE_BUILTIN___BUILTIN_SUB_OVERFLOW
 # if defined(UNREACHABLE)
-#  define RUBY3_HAS_BUILTIN___builtin_unreachable 1
+#  define RBIMPL_HAS_BUILTIN___builtin_unreachable 1
 # endif
 #endif
 
-#endif /* RUBY3_HAS_BUILTIN_H */
+#endif /* RBIMPL_HAS_BUILTIN_H */
diff --git a/include/ruby/impl/has/c_attribute.h b/include/ruby/impl/has/c_attribute.h
index e883eb71e6..874d83467d 100644
--- a/include/ruby/impl/has/c_attribute.h
+++ b/include/ruby/impl/has/c_attribute.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_C_ATTRIBUTE_H                      /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_C_ATTRIBUTE_H
+#ifndef RBIMPL_HAS_C_ATTRIBUTE_H                     /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_C_ATTRIBUTE_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,21 +18,21 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_C_ATTRIBUTE.
+ * @brief      Defines #RBIMPL_HAS_C_ATTRIBUTE.
  */
 
 /** Wraps (or simulates) `__has_c_attribute`. */
 #if defined(__cplusplus)
 # /* Makes no sense. */
-# define RUBY3_HAS_C_ATTRIBUTE(_) 0
+# define RBIMPL_HAS_C_ATTRIBUTE(_) 0
 
 #elif defined(__has_c_attribute)
-# define RUBY3_HAS_C_ATTRIBUTE(_) __has_c_attribute(_)
+# define RBIMPL_HAS_C_ATTRIBUTE(_) __has_c_attribute(_)
 
 #else
 # /* As  of writing  everything  that lacks  __has_c_attribute also  completely
 #  * lacks C2x attributes as well.  Might change in future? */
-# define RUBY3_HAS_C_ATTRIBUTE(_) 0
+# define RBIMPL_HAS_C_ATTRIBUTE(_) 0
 #endif
 
-#endif /* RUBY3_HAS_C_ATTRIBUTE_H */
+#endif /* RBIMPL_HAS_C_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/cpp_attribute.h b/include/ruby/impl/has/cpp_attribute.h
index 922ad6b67b..69ea5fbc55 100644
--- a/include/ruby/impl/has/cpp_attribute.h
+++ b/include/ruby/impl/has/cpp_attribute.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_CPP_ATTRIBUTE_H                    /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_CPP_ATTRIBUTE_H
+#ifndef RBIMPL_HAS_CPP_ATTRIBUTE_H                   /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_CPP_ATTRIBUTE_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,7 +18,7 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_CPP_ATTRIBUTE.
+ * @brief      Defines #RBIMPL_HAS_CPP_ATTRIBUTE.
  */
 #include "ruby/impl/compiler_is.h"
 #include "ruby/impl/compiler_since.h"
@@ -26,35 +26,35 @@
 
 /** @cond INTERNAL_MACRO */
 #if defined(__has_cpp_attribute)
-# define RUBY3_HAS_CPP_ATTRIBUTE0(_) __has_cpp_attribute(_)
+# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) __has_cpp_attribute(_)
 
-#elif RUBY3_COMPILER_IS(MSVC)
+#elif RBIMPL_COMPILER_IS(MSVC)
 # /* MSVC has  never updated  its __cplusplus  since forever  (unless specified
 #  * explicitly by a compiler flag).   They also lack __has_cpp_attribute until
 #  * 2019.  However, they do have attributes since 2015 or so. */
 # /* https://docs.microsoft.com/en-us/cpp/overview/visual-cpp-language-conformance */
-# define RUBY3_HAS_CPP_ATTRIBUTE0(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_CPP_ATTRIBUTE_, _)
-# define RUBY3_HAS_CPP_ATTRIBUTE_noreturn           200809 * RUBY3_COMPILER_SINCE(MSVC, 19, 00, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_carries_dependency 200809 * RUBY3_COMPILER_SINCE(MSVC, 19, 00, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_deprecated         201309 * RUBY3_COMPILER_SINCE(MSVC, 19, 10, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_fallthrough        201603 * RUBY3_COMPILER_SINCE(MSVC, 19, 10, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_maybe_unused       201603 * RUBY3_COMPILER_SINCE(MSVC, 19, 11, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_nodiscard          201603 * RUBY3_COMPILER_SINCE(MSVC, 19, 11, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_CPP_ATTRIBUTE_, _)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_noreturn           200809 * RBIMPL_COMPILER_SINCE(MSVC, 19, 00, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_carries_dependency 200809 * RBIMPL_COMPILER_SINCE(MSVC, 19, 00, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_deprecated         201309 * RBIMPL_COMPILER_SINCE(MSVC, 19, 10, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_fallthrough        201603 * RBIMPL_COMPILER_SINCE(MSVC, 19, 10, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_maybe_unused       201603 * RBIMPL_COMPILER_SINCE(MSVC, 19, 11, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_nodiscard          201603 * RBIMPL_COMPILER_SINCE(MSVC, 19, 11, 0)
 
-#elif RUBY3_COMPILER_BEFORE(Clang, 3, 6, 0)
+#elif RBIMPL_COMPILER_BEFORE(Clang, 3, 6, 0)
 # /* Clang  3.6.0  introduced  __has_cpp_attribute.  Prior  to  that  following
 #  * attributes were already there. */
 # /* https://clang.llvm.org/cxx_status.html */
-# define RUBY3_HAS_CPP_ATTRIBUTE0(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_CPP_ATTRIBUTE_, _)
-# define RUBY3_HAS_CPP_ATTRIBUTE_noreturn           200809 * RUBY3_COMPILER_SINCE(Clang, 3, 3, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_deprecated         201309 * RUBY3_COMPILER_SINCE(Clang, 3, 4, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_CPP_ATTRIBUTE_, _)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_noreturn           200809 * RBIMPL_COMPILER_SINCE(Clang, 3, 3, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_deprecated         201309 * RBIMPL_COMPILER_SINCE(Clang, 3, 4, 0)
 
-#elif RUBY3_COMPILER_BEFORE(GCC, 5, 0, 0)
+#elif RBIMPL_COMPILER_BEFORE(GCC, 5, 0, 0)
 # /* GCC 5+ have __has_cpp_attribute, while 4.x had following attributes. */
 # /* https://gcc.gnu.org/projects/cxx-status.html */
-# define RUBY3_HAS_CPP_ATTRIBUTE0(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_CPP_ATTRIBUTE_, _)
-# define RUBY3_HAS_CPP_ATTRIBUTE_noreturn           200809 * RUBY3_COMPILER_SINCE(GCC, 4, 8, 0)
-# define RUBY3_HAS_CPP_ATTRIBUTE_deprecated         201309 * RUBY3_COMPILER_SINCE(GCC, 4, 9, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_CPP_ATTRIBUTE_, _)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_noreturn           200809 * RBIMPL_COMPILER_SINCE(GCC, 4, 8, 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE_deprecated         201309 * RBIMPL_COMPILER_SINCE(GCC, 4, 9, 0)
 
 #else
 # /* :FIXME:
@@ -62,18 +62,18 @@
 #  * - icpc: They have __INTEL_CXX11_MODE__.
 #  * - SunPro: Seems they support C++11.
 #  */
-# define RUBY3_HAS_CPP_ATTRIBUTE0(_) 0
+# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) 0
 #endif
 /** @endcond */
 
 /** Wraps (or simulates) `__has_cpp_attribute`. */
 #if ! defined(__cplusplus)
 # /* Makes no sense. */
-# define RUBY3_HAS_CPP_ATTRIBUTE(_) 0
+# define RBIMPL_HAS_CPP_ATTRIBUTE(_) 0
 #else
 # /* GCC needs workarounds.  See https://gcc.godbolt.org/z/jdz3pa */
-# define RUBY3_HAS_CPP_ATTRIBUTE(_) \
-    ((RUBY3_HAS_CPP_ATTRIBUTE0(_) <= __cplusplus) ? RUBY3_HAS_CPP_ATTRIBUTE0(_) : 0)
+# define RBIMPL_HAS_CPP_ATTRIBUTE(_) \
+    ((RBIMPL_HAS_CPP_ATTRIBUTE0(_) <= __cplusplus) ? RBIMPL_HAS_CPP_ATTRIBUTE0(_) : 0)
 #endif
 
-#endif /* RUBY3_HAS_CPP_ATTRIBUTE_H */
+#endif /* RBIMPL_HAS_CPP_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/declspec_attribute.h b/include/ruby/impl/has/declspec_attribute.h
index 317bd9989a..5f1d388245 100644
--- a/include/ruby/impl/has/declspec_attribute.h
+++ b/include/ruby/impl/has/declspec_attribute.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_DECLSPEC_ATTRIBUTE_H               /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_DECLSPEC_ATTRIBUTE_H
+#ifndef RBIMPL_HAS_DECLSPEC_ATTRIBUTE_H              /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,31 +18,31 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_DECLSPEC_ATTRIBUTE.
+ * @brief      Defines #RBIMPL_HAS_DECLSPEC_ATTRIBUTE.
  */
 #include "ruby/impl/compiler_since.h"
 #include "ruby/impl/token_paste.h"
 
 /** Wraps (or simulates) `__has_declspec_attribute`. */
 #if defined(__has_declspec_attribute)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE(_) __has_declspec_attribute(_)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE(_) __has_declspec_attribute(_)
 #else
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_DECLSPEC_ATTRIBUTE_, _)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_align       RUBY3_COMPILER_SINCE(MSVC, 8, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_deprecated  RUBY3_COMPILER_SINCE(MSVC,13, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_dllexport   RUBY3_COMPILER_SINCE(MSVC, 8, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_dllimport   RUBY3_COMPILER_SINCE(MSVC, 8, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_empty_bases RUBY3_COMPILER_SINCE(MSVC,19, 0, 23918)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_noalias     RUBY3_COMPILER_SINCE(MSVC, 8, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_noinline    RUBY3_COMPILER_SINCE(MSVC,13, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_noreturn    RUBY3_COMPILER_SINCE(MSVC,11, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_nothrow     RUBY3_COMPILER_SINCE(MSVC, 8, 0, 0)
-# define RUBY3_HAS_DECLSPEC_ATTRIBUTE_restrict    RUBY3_COMPILER_SINCE(MSVC,14, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE(_) RBIMPL_TOKEN_PASTE(RBIMPL_HAS_DECLSPEC_ATTRIBUTE_, _)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_align       RBIMPL_COMPILER_SINCE(MSVC, 8, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_deprecated  RBIMPL_COMPILER_SINCE(MSVC,13, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_dllexport   RBIMPL_COMPILER_SINCE(MSVC, 8, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_dllimport   RBIMPL_COMPILER_SINCE(MSVC, 8, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_empty_bases RBIMPL_COMPILER_SINCE(MSVC,19, 0, 23918)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_noalias     RBIMPL_COMPILER_SINCE(MSVC, 8, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_noinline    RBIMPL_COMPILER_SINCE(MSVC,13, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_noreturn    RBIMPL_COMPILER_SINCE(MSVC,11, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_nothrow     RBIMPL_COMPILER_SINCE(MSVC, 8, 0, 0)
+# define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_restrict    RBIMPL_COMPILER_SINCE(MSVC,14, 0, 0)
 # /* Note that "8, 0, 0" might be inaccurate. */
 # if ! defined(__cplusplus)
 #  /* Clang has this in both C/C++, but MSVC has this in C++ only.*/
-#  undef RUBY3_HAS_DECLSPEC_ATTRIBUTE_nothrow
+#  undef RBIMPL_HAS_DECLSPEC_ATTRIBUTE_nothrow
 # endif
 #endif
 
-#endif /* RUBY3_HAS_DECLSPEC_ATTRIBUTE_H */
+#endif /* RBIMPL_HAS_DECLSPEC_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/extension.h b/include/ruby/impl/has/extension.h
index b985f6d4f8..d1cbc9b1d6 100644
--- a/include/ruby/impl/has/extension.h
+++ b/include/ruby/impl/has/extension.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_EXTENSION_H                        /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_EXTENSION_H
+#ifndef RBIMPL_HAS_EXTENSION_H                       /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_EXTENSION_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,16 +18,16 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_EXTENSION.
+ * @brief      Defines #RBIMPL_HAS_EXTENSION.
  */
 #include "ruby/impl/has/feature.h"
 
 /** Wraps (or simulates) `__has_extension`. */
 #if defined(__has_extension)
-# define RUBY3_HAS_EXTENSION(_) __has_extension(_)
+# define RBIMPL_HAS_EXTENSION(_) __has_extension(_)
 #else
 # /* Pre-3.0 clang had __has_feature but not __has_extension. */
-# define RUBY3_HAS_EXTENSION(_) RUBY3_HAS_FEATURE(_)
+# define RBIMPL_HAS_EXTENSION(_) RBIMPL_HAS_FEATURE(_)
 #endif
 
-#endif /* RUBY3_HAS_EXTENSION_H */
+#endif /* RBIMPL_HAS_EXTENSION_H */
diff --git a/include/ruby/impl/has/feature.h b/include/ruby/impl/has/feature.h
index f64c756817..bc0c5b22ad 100644
--- a/include/ruby/impl/has/feature.h
+++ b/include/ruby/impl/has/feature.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_FEATURE_H                          /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_FEATURE_H
+#ifndef RBIMPL_HAS_FEATURE_H                         /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_FEATURE_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,14 +18,14 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_FEATURE.
+ * @brief      Defines #RBIMPL_HAS_FEATURE.
  */
 
 /** Wraps (or simulates) `__has_feature`. */
 #if defined(__has_feature)
-# define RUBY3_HAS_FEATURE(_) __has_feature(_)
+# define RBIMPL_HAS_FEATURE(_) __has_feature(_)
 #else
-# define RUBY3_HAS_FEATURE(_) 0
+# define RBIMPL_HAS_FEATURE(_) 0
 #endif
 
-#endif /* RUBY3_HAS_FEATURE_H */
+#endif /* RBIMPL_HAS_FEATURE_H */
diff --git a/include/ruby/impl/has/warning.h b/include/ruby/impl/has/warning.h
index 3ec8e8f79e..4200ce877d 100644
--- a/include/ruby/impl/has/warning.h
+++ b/include/ruby/impl/has/warning.h
@@ -1,5 +1,5 @@
-#ifndef RUBY3_HAS_WARNING_H                          /*-*-C++-*-vi:se ft=cpp:*/
-#define RUBY3_HAS_WARNING_H
+#ifndef RBIMPL_HAS_WARNING_H                         /*-*-C++-*-vi:se ft=cpp:*/
+#define RBIMPL_HAS_WARNING_H
 /**
  * @file
  * @author     Ruby developers <ruby-core@ruby-lang.org>
@@ -7,7 +7,7 @@
  *             Permission  is hereby  granted,  to  either redistribute  and/or
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
- * @warning    Symbols   prefixed   with   either  `RUBY3`   or   `ruby3`   are
+ * @warning    Symbols   prefixed  with   either  `RBIMPL`   or   `ruby3`   are
  *             implementation details.   Don't take  them as canon.  They could
  *             rapidly appear then vanish.  The name (path) of this header file
  *             is also an  implementation detail.  Do not expect  it to persist
@@ -18,14 +18,14 @@
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
  *             extension libraries. They could be written in C++98.
- * @brief      Defines #RUBY3_HAS_WARNING.
+ * @brief      Defines #RBIMPL_HAS_WARNING.
  */
 
 /** Wraps (or simulates) `__has_warning`. */
 #if defined(__has_warning)
-# define RUBY3_HAS_WARNING(_) __has_warning(_)
+# define RBIMPL_HAS_WARNING(_) __has_warning(_)
 #else
-# define RUBY3_HAS_WARNING(_) 0
+# define RBIMPL_HAS_WARNING(_) 0
 #endif
 
-#endif /* RUBY3_HAS_WARNING_H */
+#endif /* RBIMPL_HAS_WARNING_H */