split internal.h into files

One day, I could not resist the way it was written.  I finally started
to make the code clean.  This changeset is the beginning of a series of
housekeeping commits.  It is a simple refactoring; split internal.h into
files, so that we can divide and concur in the upcoming commits.  No
lines of codes are either added or removed, except the obvious file
headers/footers.  The generated binary is identical to the one before.

1 files changed, 21 insertions, 0 deletions

diff --git a/internal/static_assert.h b/internal/static_assert.h
new file mode 100644
index 0000000000..05b79b4ba3
--- /dev/null
+++ b/internal/static_assert.h
@@ -0,0 +1,21 @@
+#ifndef INTERNAL_STATIC_ASSERT_H /* -*- C -*- */
+#define INTERNAL_STATIC_ASSERT_H
+/**
+ * @file
+ * @brief      C11 shim for _Static_assert.
+ * @author     \@shyouhei
+ * @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.
+ */
+
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
+# define STATIC_ASSERT(name, expr) _Static_assert(expr, #name ": " #expr)
+#elif GCC_VERSION_SINCE(4, 6, 0) || __has_extension(c_static_assert)
+# define STATIC_ASSERT(name, expr) RB_GNUC_EXTENSION _Static_assert(expr, #name ": " #expr)
+#else
+# define STATIC_ASSERT(name, expr) typedef int static_assert_##name##_check[1 - 2*!(expr)]
+#endif
+
+#endif /* INTERNAL_STATIC_ASSERT_H */