8 files changed, 0 insertions, 529 deletions
diff --git a/include/ruby/impl/has/attribute.h b/include/ruby/impl/has/attribute.h
deleted file mode 100644
index af51b93298..0000000000
--- a/include/ruby/impl/has/attribute.h
+++ /dev/null
@@ -1,164 +0,0 @@
-#ifndef RBIMPL_HAS_ATTRIBUTE_H                       /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_ATTRIBUTE_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #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) || 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 RBIMPL_HAVE___HAS_ATTRIBUTE 1
-# endif
-#endif
-
-/** Wraps (or simulates) `__has_attribute`. */
-#if defined(RBIMPL_HAVE___HAS_ATTRIBUTE)
-# define RBIMPL_HAS_ATTRIBUTE(_) __has_attribute(_)
-
-#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 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 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 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 RBIMPL_HAS_ATTRIBUTE(_) 0
-# /* Fallback below doesn't work: see win32/Makefile.sub */
-
-#else
-# /* Take config.h definition when available. */
-# define RBIMPL_HAS_ATTRIBUTE(_) (RBIMPL_TOKEN_PASTE(RBIMPL_HAS_ATTRIBUTE_, _)+0)
-# ifdef ALWAYS_INLINE
-#  define RBIMPL_HAS_ATTRIBUTE_always_inline 1
-# endif
-# ifdef FUNC_CDECL
-#  define RBIMPL_HAS_ATTRIBUTE_cdecl 1
-# endif
-# ifdef CONSTFUNC
-#  define RBIMPL_HAS_ATTRIBUTE_const 1
-# endif
-# ifdef DEPRECATED
-#  define RBIMPL_HAS_ATTRIBUTE_deprecated 1
-# endif
-# ifdef ERRORFUNC
-#  define RBIMPL_HAS_ATTRIBUTE_error 1
-# endif
-# ifdef FUNC_FASTCALL
-#  define RBIMPL_HAS_ATTRIBUTE_fastcall 1
-# endif
-# ifdef PUREFUNC
-#  define RBIMPL_HAS_ATTRIBUTE_pure 1
-# endif
-# ifdef NO_ADDRESS_SAFETY_ANALYSIS
-#  define RBIMPL_HAS_ATTRIBUTE_no_address_safety_analysis 1
-# endif
-# ifdef NO_SANITIZE
-#  define RBIMPL_HAS_ATTRIBUTE_no_sanitize 1
-# endif
-# ifdef NO_SANITIZE_ADDRESS
-#  define RBIMPL_HAS_ATTRIBUTE_no_sanitize_address 1
-# endif
-# ifdef NOINLINE
-#  define RBIMPL_HAS_ATTRIBUTE_noinline 1
-# endif
-# ifdef RBIMPL_FUNC_NONNULL
-#  define RBIMPL_HAS_ATTRIBUTE_nonnull 1
-# endif
-# ifdef NORETURN
-#  define RBIMPL_HAS_ATTRIBUTE_noreturn 1
-# endif
-# ifdef FUNC_OPTIMIZED
-#  define RBIMPL_HAS_ATTRIBUTE_optimize 1
-# endif
-# ifdef FUNC_STDCALL
-#  define RBIMPL_HAS_ATTRIBUTE_stdcall 1
-# endif
-# ifdef MAYBE_UNUSED
-#  define RBIMPL_HAS_ATTRIBUTE_unused 1
-# endif
-# ifdef WARN_UNUSED_RESULT
-#  define RBIMPL_HAS_ATTRIBUTE_warn_unused_result 1
-# endif
-# ifdef WARNINGFUNC
-#  define RBIMPL_HAS_ATTRIBUTE_warning 1
-# endif
-# ifdef WEAK
-#  define RBIMPL_HAS_ATTRIBUTE_weak 1
-# endif
-#endif
-
-#endif /* RBIMPL_HAS_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/builtin.h b/include/ruby/impl/has/builtin.h
deleted file mode 100644
index 46f587c2cf..0000000000
--- a/include/ruby/impl/has/builtin.h
+++ /dev/null
@@ -1,105 +0,0 @@
-#ifndef RBIMPL_HAS_BUILTIN_H                         /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_BUILTIN_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #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 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 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 RBIMPL_HAVE___HAS_BUILTIN 1
-# endif
-#endif
-
-/** Wraps (or simulates) `__has_builtin`. */
-#if defined(RBIMPL_HAVE___HAS_BUILTIN)
-# define RBIMPL_HAS_BUILTIN(_) __has_builtin(_)
-
-#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 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 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 RBIMPL_COMPILER_IS(MSVC)
-# /* MSVC has UNREACHABLE, but that is not __builtin_unreachable. */
-# define RBIMPL_HAS_BUILTIN(_) 0
-
-#else
-# /* Take config.h definition when available */
-# 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 RBIMPL_HAS_BUILTIN___builtin_unreachable 1
-# endif
-#endif
-
-#endif /* RBIMPL_HAS_BUILTIN_H */
diff --git a/include/ruby/impl/has/c_attribute.h b/include/ruby/impl/has/c_attribute.h
deleted file mode 100644
index b7eb94d22a..0000000000
--- a/include/ruby/impl/has/c_attribute.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef RBIMPL_HAS_C_ATTRIBUTE_H                     /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_C_ATTRIBUTE_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #RBIMPL_HAS_C_ATTRIBUTE.
- */
-
-/** Wraps (or simulates) `__has_c_attribute`. */
-#if defined(__cplusplus)
-# /* Makes no sense. */
-# define RBIMPL_HAS_C_ATTRIBUTE(_) 0
-
-#elif defined(__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 RBIMPL_HAS_C_ATTRIBUTE(_) 0
-#endif
-
-#endif /* RBIMPL_HAS_C_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/cpp_attribute.h b/include/ruby/impl/has/cpp_attribute.h
deleted file mode 100644
index 12847a11d6..0000000000
--- a/include/ruby/impl/has/cpp_attribute.h
+++ /dev/null
@@ -1,79 +0,0 @@
-#ifndef RBIMPL_HAS_CPP_ATTRIBUTE_H                   /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_CPP_ATTRIBUTE_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #RBIMPL_HAS_CPP_ATTRIBUTE.
- */
-#include "ruby/impl/compiler_is.h"
-#include "ruby/impl/compiler_since.h"
-#include "ruby/impl/token_paste.h"
-
-/** @cond INTERNAL_MACRO */
-#if defined(__has_cpp_attribute)
-# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) __has_cpp_attribute(_)
-
-#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 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 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 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 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 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:
-#  * Candidate compilers to list here:
-#  * - icpc: They have __INTEL_CXX11_MODE__.
-#  * - SunPro: Seems they support C++11.
-#  */
-# define RBIMPL_HAS_CPP_ATTRIBUTE0(_) 0
-#endif
-/** @endcond */
-
-/** Wraps (or simulates) `__has_cpp_attribute`. */
-#if ! defined(__cplusplus)
-# /* Makes no sense. */
-# define RBIMPL_HAS_CPP_ATTRIBUTE(_) 0
-#else
-# /* GCC needs workarounds.  See https://gcc.godbolt.org/z/jdz3pa */
-# define RBIMPL_HAS_CPP_ATTRIBUTE(_) \
-    ((RBIMPL_HAS_CPP_ATTRIBUTE0(_) <= __cplusplus) ? RBIMPL_HAS_CPP_ATTRIBUTE0(_) : 0)
-#endif
-
-#endif /* RBIMPL_HAS_CPP_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/declspec_attribute.h b/include/ruby/impl/has/declspec_attribute.h
deleted file mode 100644
index ba6ad98fce..0000000000
--- a/include/ruby/impl/has/declspec_attribute.h
+++ /dev/null
@@ -1,48 +0,0 @@
-#ifndef RBIMPL_HAS_DECLSPEC_ATTRIBUTE_H              /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_DECLSPEC_ATTRIBUTE_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #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 RBIMPL_HAS_DECLSPEC_ATTRIBUTE(_) __has_declspec_attribute(_)
-#else
-# 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 RBIMPL_HAS_DECLSPEC_ATTRIBUTE_nothrow
-# endif
-#endif
-
-#endif /* RBIMPL_HAS_DECLSPEC_ATTRIBUTE_H */
diff --git a/include/ruby/impl/has/extension.h b/include/ruby/impl/has/extension.h
deleted file mode 100644
index 02a48bc74c..0000000000
--- a/include/ruby/impl/has/extension.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef RBIMPL_HAS_EXTENSION_H                       /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_EXTENSION_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #RBIMPL_HAS_EXTENSION.
- */
-#include "ruby/impl/has/feature.h"
-
-/** Wraps (or simulates) `__has_extension`. */
-#if defined(__has_extension)
-# define RBIMPL_HAS_EXTENSION(_) __has_extension(_)
-#else
-# /* Pre-3.0 clang had __has_feature but not __has_extension. */
-# define RBIMPL_HAS_EXTENSION(_) RBIMPL_HAS_FEATURE(_)
-#endif
-
-#endif /* RBIMPL_HAS_EXTENSION_H */
diff --git a/include/ruby/impl/has/feature.h b/include/ruby/impl/has/feature.h
deleted file mode 100644
index b827590c00..0000000000
--- a/include/ruby/impl/has/feature.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#ifndef RBIMPL_HAS_FEATURE_H                         /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_FEATURE_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #RBIMPL_HAS_FEATURE.
- */
-
-/** Wraps (or simulates) `__has_feature`. */
-#if defined(__has_feature)
-# define RBIMPL_HAS_FEATURE(_) __has_feature(_)
-#else
-# define RBIMPL_HAS_FEATURE(_) 0
-#endif
-
-#endif /* RBIMPL_HAS_FEATURE_H */
diff --git a/include/ruby/impl/has/warning.h b/include/ruby/impl/has/warning.h
deleted file mode 100644
index 03975ecc2f..0000000000
--- a/include/ruby/impl/has/warning.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#ifndef RBIMPL_HAS_WARNING_H                         /*-*-C++-*-vi:se ft=cpp:*/
-#define RBIMPL_HAS_WARNING_H
-/**
- * @file
- * @author     Ruby developers <[email protected]>
- * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
- *             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  `RBIMPL`   or  `rbimpl`   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
- *             at the place it is now.  Developers are free to move it anywhere
- *             anytime at will.
- * @note       To  ruby-core:  remember  that   this  header  can  be  possibly
- *             recursively included  from extension  libraries written  in C++.
- *             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 #RBIMPL_HAS_WARNING.
- */
-
-/** Wraps (or simulates) `__has_warning`. */
-#if defined(__has_warning)
-# define RBIMPL_HAS_WARNING(_) __has_warning(_)
-#else
-# define RBIMPL_HAS_WARNING(_) 0
-#endif
-
-#endif /* RBIMPL_HAS_WARNING_H */