1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
ruby--ruby/include/ruby/3/arithmetic/short.h
卜部昌平 4ff3f20540 add #include guard hack
According to MSVC manual (*1), cl.exe can skip including a header file
when that:

- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.

GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).

Sun C lacked #pragma once for a looong time.  Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.

This changeset modifies header files so that each of them include
strictly one #ifndef...#endif.  I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]

*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
2020-04-13 16:06:00 +09:00

54 lines
2.2 KiB
C++

#ifndef RUBY3_ARITHMETIC_SHORT_H /*-*-C++-*-vi:se ft=cpp:*/
#define RUBY3_ARITHMETIC_SHORT_H
/**
* @file
* @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.
* @warning Symbols prefixed with either `RUBY3` 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
* 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 Arithmetic conversion between C's `short` and Ruby's.
*
* Shyouhei wonders: why there is no SHORT2NUM, given there are both
* #USHORT2NUM and #CHR2FIX?
*/
#include "ruby/3/value.h"
#include "ruby/3/dllexport.h"
#include "ruby/3/special_consts.h"
#define RB_NUM2SHORT rb_num2short_inline
#define RB_NUM2USHORT rb_num2ushort
#define NUM2SHORT RB_NUM2SHORT
#define NUM2USHORT RB_NUM2USHORT
#define USHORT2NUM RB_INT2FIX
#define RB_FIX2SHORT rb_fix2short
#define FIX2SHORT RB_FIX2SHORT
RUBY3_SYMBOL_EXPORT_BEGIN()
short rb_num2short(VALUE);
unsigned short rb_num2ushort(VALUE);
short rb_fix2short(VALUE);
unsigned short rb_fix2ushort(VALUE);
RUBY3_SYMBOL_EXPORT_END()
static inline short
rb_num2short_inline(VALUE x)
{
if (RB_FIXNUM_P(x))
return rb_fix2short(x);
else
return rb_num2short(x);
}
#endif /* RUBY3_ARITHMETIC_SOHRT_H */