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ruby--ruby/internal/util.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

31 lines
1.3 KiB
C

#ifndef INTERNAL_UTIL_H /*-*-C-*-vi:se ft=c:*/
#define INTERNAL_UTIL_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.
* @brief Internal header corresponding util.c.
* @warning DO NOT ADD RANDOM GARBAGE HERE THIS FILE IS FOR util.c
*/
#include "ruby/3/config.h"
#include <stddef.h> /* for size_t */
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h> /* for ssize_t (note: on Windows ssize_t is */
#endif /* `#define`d in ruby/config.h) */
/* util.c */
char *ruby_dtoa(double d_, int mode, int ndigits, int *decpt, int *sign, char **rve);
char *ruby_hdtoa(double d, const char *xdigs, int ndigits, int *decpt, int *sign, char **rve);
RUBY_SYMBOL_EXPORT_BEGIN
/* util.c (export) */
extern const signed char ruby_digit36_to_number_table[];
extern const char ruby_hexdigits[];
extern unsigned long ruby_scan_digits(const char *str, ssize_t len, int base, size_t *retlen, int *overflow);
RUBY_SYMBOL_EXPORT_END
#endif /* INTERNAL_UTIL_H */