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ruby--ruby/ruby_assert.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

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C

#ifndef RUBY_TOPLEVEL_ASSERT_H /*-*-C-*-vi:se ft=c:*/
#define RUBY_TOPLEVEL_ASSERT_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.
*/
#include "ruby/assert.h"
#if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L)
/* C89 compilers are required to support strings of only 509 chars. */
/* can't use RUBY_ASSERT for such compilers. */
#include <assert.h>
#else
#undef assert
#define assert RUBY_ASSERT
#endif
#endif /* RUBY_TOPLEVEL_ASSERT_H */