1 files changed, 107 insertions, 0 deletions
diff --git a/internal/compilers.h b/internal/compilers.h
new file mode 100644
index 0000000000..26c2f05cc0
--- /dev/null
+++ b/internal/compilers.h
@@ -0,0 +1,107 @@
+#ifndef INTERNAL_COMPILERS_H                             /*-*-C-*-vi:se ft=c:*/
+#define INTERNAL_COMPILERS_H
+/**
+ * @author     Ruby developers <ruby-core@ruby-lang.org>
+ * @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.
+ * @brief      Internal header absorbing C compiler differences.
+ */
+#include "ruby/internal/compiler_since.h"
+#include "ruby/internal/has/attribute.h"
+#include "ruby/internal/has/builtin.h"
+#include "ruby/internal/has/c_attribute.h"
+#include "ruby/internal/has/declspec_attribute.h"
+#include "ruby/internal/has/extension.h"
+#include "ruby/internal/has/feature.h"
+#include "ruby/internal/has/warning.h"
+#include "ruby/backward/2/gcc_version_since.h"
+
+#define MSC_VERSION_SINCE(_)   RBIMPL_COMPILER_SINCE(MSVC, (_) / 100, (_) % 100, 0)
+#define MSC_VERSION_BEFORE(_)  RBIMPL_COMPILER_BEFORE(MSVC, (_) / 100, (_) % 100, 0)
+
+#ifndef __has_attribute
+# define __has_attribute(...) RBIMPL_HAS_ATTRIBUTE(__VA_ARGS__)
+#endif
+
+#ifndef __has_c_attribute
+# /* As  of writing  everything  that lacks  __has_c_attribute also  completely
+#  * lacks C2x attributes as well.  Might change in future? */
+# define __has_c_attribute(...) 0
+#endif
+
+#ifndef __has_declspec_attribute
+# define __has_declspec_attribute(...) RBIMPL_HAS_DECLSPEC_ATTRIBUTE(__VA_ARGS__)
+#endif
+
+#ifndef __has_builtin
+# define __has_builtin(...) RBIMPL_HAS_BUILTIN(__VA_ARGS__)
+#endif
+
+#ifndef __has_feature
+# define __has_feature(...) RBIMPL_HAS_FEATURE(__VA_ARGS__)
+#endif
+
+#ifndef __has_extension
+# define __has_extension(...) RBIMPL_HAS_EXTENSION(__VA_ARGS__)
+#endif
+
+#ifndef __has_warning
+# define __has_warning(...) RBIMPL_HAS_WARNING(__VA_ARGS__)
+#endif
+
+#ifndef __GNUC__
+# define __extension__ /* void */
+#endif
+
+#ifndef MAYBE_UNUSED
+# define MAYBE_UNUSED(x) x
+#endif
+
+#ifndef WARN_UNUSED_RESULT
+# define WARN_UNUSED_RESULT(x) x
+#endif
+
+#define RB_OBJ_BUILTIN_TYPE(obj) rb_obj_builtin_type(obj)
+#define OBJ_BUILTIN_TYPE(obj) RB_OBJ_BUILTIN_TYPE(obj)
+#ifdef __GNUC__
+#define rb_obj_builtin_type(obj) \
+__extension__({ \
+    VALUE arg_obj = (obj); \
+    RB_SPECIAL_CONST_P(arg_obj) ? -1 : \
+        (int)RB_BUILTIN_TYPE(arg_obj);    \
+    })
+#else
+# include "ruby/ruby.h"
+static inline int
+rb_obj_builtin_type(VALUE obj)
+{
+    return RB_SPECIAL_CONST_P(obj) ? -1 :
+        (int)RB_BUILTIN_TYPE(obj);
+}
+#endif
+
+/* A macro for defining a flexible array, like: VALUE ary[FLEX_ARY_LEN]; */
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+# define FLEX_ARY_LEN   /* VALUE ary[]; */
+#elif defined(__GNUC__) && !defined(__STRICT_ANSI__)
+# define FLEX_ARY_LEN 0 /* VALUE ary[0]; */
+#else
+# define FLEX_ARY_LEN 1 /* VALUE ary[1]; */
+#endif
+
+/*
+ * For declaring bitfields out of non-unsigned int types:
+ *   struct date {
+ *      BITFIELD(enum months, month, 4);
+ *      ...
+ *   };
+ */
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+# define BITFIELD(type, name, size) type name : size
+#else
+# define BITFIELD(type, name, size) unsigned int name : size
+#endif
+
+#endif /* INTERNAL_COMPILERS_H */