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ruby--ruby/include/ruby/util.h
卜部昌平 fd12bc1896 ruby_scan_oct, ruby_scan_hex: are not pure
Silly bug, they write back consumed bytes through passed pointers.  Must
never be pure functions.

ruby_scan_oct does not refer any static variables so it can still be
__declspec(noalias), while ruby_scan_hex is not because it reads from
ruby_digit36_to_number_table.
2021-09-10 20:00:06 +09:00

228 lines
8.2 KiB
C++

#ifndef RUBY_UTIL_H /*-*-C++-*-vi:se ft=cpp:*/
#define RUBY_UTIL_H 1
/**
* @file
* @author $Author$
* @date Thu Mar 9 11:55:53 JST 1995
* @copyright Copyright (C) 1993-2007 Yukihiro Matsumoto
* @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 DO NOT ADD RANDOM GARBAGES IN THIS FILE! Contents of this file
* reside here for historical reasons. Find a right place for your
* API!
*/
#include "ruby/internal/config.h"
#ifdef STDC_HEADERS
# include <stddef.h> /* size_t */
#endif
#if HAVE_SYS_TYPES_H
# include <sys/types.h> /* ssize_t */
#endif
#include "ruby/internal/attr/noalias.h"
#include "ruby/internal/attr/nodiscard.h"
#include "ruby/internal/attr/nonnull.h"
#include "ruby/internal/attr/restrict.h"
#include "ruby/internal/attr/returns_nonnull.h"
#include "ruby/internal/dllexport.h"
#include "ruby/defines.h"
RBIMPL_SYMBOL_EXPORT_BEGIN()
/** an approximation of ceil(n * log10(2)), up to 65536 at least */
#define DECIMAL_SIZE_OF_BITS(n) (((n) * 3010 + 9998) / 9999)
/**
* Character to number mapping like `'a'` -> `10`, `'b'` -> `11` etc. For
* punctuation etc., the value is -1. "36" terminology comes from the fact
* that this is the table behind `str.to_i(36)`.
*/
RUBY_EXTERN const signed char ruby_digit36_to_number_table[];
/**
* Characters that Ruby accepts as hexadecimal digits. This is `/\h/` expanded
* into an array.
*/
RUBY_EXTERN const char ruby_hexdigits[];
/**
* Scans the passed string, assuming the string is a textual representation of
* an integer. Stops when encountering something non-digit for the passed
* base.
*
* @note This does not understand minus sign.
* @note This does not understand e.g. `0x` prefix.
* @note It is a failure to pass `0` to `base`, unlike ruby_strtoul().
* @param[in] str Target string of digits to interpret.
* @param[in] len Number of bytes of `str`, or -1 to detect `NUL`.
* @param[in] base Base, `2` to `36` inclusive.
* @param[out] retlen Return value buffer.
* @param[out] overflow Return value buffer.
* @return Interpreted numeric representation of `str`.
* @post `retlen` is the number of bytes scanned so far.
* @post `overflow` is set to true if the string represents something
* bigger than `ULONG_MAX`. Something meaningful still returns;
* which is the designed belabour of C's unsigned arithmetic.
*/
unsigned long ruby_scan_digits(const char *str, ssize_t len, int base, size_t *retlen, int *overflow);
/** @old{ruby_scan_oct} */
#define scan_oct(s,l,e) ((int)ruby_scan_oct((s),(l),(e)))
RBIMPL_ATTR_NOALIAS()
RBIMPL_ATTR_NONNULL(())
/**
* Interprets the passed string as an octal unsigned integer. Stops when
* encounters something not understood.
*
* @param[in] str C string to scan.
* @param[in] len Length of `str`.
* @param[out] consumed Return value buffer.
* @return Parsed integer.
* @post `ret` is the number of characters read.
*
* @internal
*
* No consideration is made for integer overflows. As the return value is
* unsigned this function has fully defined behaviour, but you cannot know if
* there was an integer wrap-around or not.
*/
unsigned long ruby_scan_oct(const char *str, size_t len, size_t *consumed);
/** @old{ruby_scan_hex} */
#define scan_hex(s,l,e) ((int)ruby_scan_hex((s),(l),(e)))
RBIMPL_ATTR_NONNULL(())
/**
* Interprets the passed string a hexadecimal unsigned integer. Stops when
* encounters something not understood.
*
* @param[in] str C string to scan.
* @param[in] len Length of `str`.
* @param[out] ret Return value buffer.
* @return Parsed integer.
* @post `ret` is the number of characters read.
*
* @internal
*
* No consideration is made for integer overflows. As the return value is
* unsigned this function has fully defined behaviour, but you cannot know if
* there was an integer wrap-around or not.
*/
unsigned long ruby_scan_hex(const char *str, size_t len, size_t *ret);
/**
* Reentrant implementation of quick sort. If your system provides something
* (like C11 qsort_s), this is a thin wrapper of that routine. Otherwise
* resorts to our own version.
*/
#ifdef HAVE_GNU_QSORT_R
# define ruby_qsort qsort_r
#else
void ruby_qsort(void *, const size_t, const size_t,
int (*)(const void *, const void *, void *), void *);
#endif
RBIMPL_ATTR_NONNULL((1))
/**
* Sets an environment variable. In case of POSIX this is a wrapper of
* `setenv(3)`. But there are systems which lack one. We try hard emulating.
*
* @param[in] key An environment variable.
* @param[in] val A value to be associated with `key`, or 0.
* @exception rb_eSystemCallError `setenv(3)` failed for some reason.
* @post Environment variable `key` is created if necessary. Its value
* is updated to be `val`.
*/
void ruby_setenv(const char *key, const char *val);
RBIMPL_ATTR_NONNULL(())
/**
* Deletes the passed environment variable, if any.
*
* @param[in] key An environment variable.
* @exception rb_eSystemCallError `unsetenv(3)` failed for some reason.
* @post Environment variable `key` does not exist.
*/
void ruby_unsetenv(const char *key);
RBIMPL_ATTR_NODISCARD()
RBIMPL_ATTR_RESTRICT()
RBIMPL_ATTR_RETURNS_NONNULL()
RBIMPL_ATTR_NONNULL(())
/**
* This is our own version of `strdup(3)` that uses ruby_xmalloc() instead of
* system malloc (benefits our GC).
*
* @param[in] str Target C string to duplicate.
* @return An allocated C string holding the identical contents.
* @note Return value must be discarded using ruby_xfree().
*/
char *ruby_strdup(const char *str);
#undef strdup
/**
* @alias{ruby_strdup}
*
* @internal
*
* @shyouhei doesn't think it is a wise idea. ruby_strdup()'s return value
* must be passed to ruby_xfree(), but this macro makes it almost impossible.
*/
#define strdup(s) ruby_strdup(s)
RBIMPL_ATTR_NODISCARD()
RBIMPL_ATTR_RESTRICT()
RBIMPL_ATTR_RETURNS_NONNULL()
/**
* This is our own version of `getcwd(3)` that uses ruby_xmalloc() instead of
* system malloc (benefits our GC).
*
* @return An allocated C string holding the process working directory.
* @note Return value must be discarded using ruby_xfree().
*/
char *ruby_getcwd(void);
RBIMPL_ATTR_NONNULL((1))
/**
* Our own locale-insensitive version of `strtod(3)`. The conversion is done
* as if the current locale is set to the "C" locale, no matter actual runtime
* locale settings.
*
* @param[in] str Decimal or hexadecimal representation of a floating
* point number.
* @param[out] endptr NULL, or an arbitrary pointer (overwritten on return).
* @return Converted number.
* @post If `endptr` is not NULL, it is updated to point the first such
* byte where conversion failed.
* @note This function sets `errno` on failure.
* - `ERANGE`: Converted integer is out of range of `double`.
* @see William D. Clinger, "How to Read Floating Point Numbers
* Accurately" in Proc. ACM SIGPLAN '90, pp. 92-101.
* https://doi.org/10.1145/93542.93557
*/
double ruby_strtod(const char *str, char **endptr);
#undef strtod
/** @alias{ruby_strtod} */
#define strtod(s,e) ruby_strtod((s),(e))
RBIMPL_ATTR_NONNULL((2))
/**
* Scans the passed string, with calling the callback function every time it
* encounters a "word". A word here is a series of characters separated by
* either a space (of IEEE 1003.1 section 7.3.1.1), or a `','`.
*
* @param[in] str Target string to split into each words.
* @param[in] func Callback function.
* @param[in,out] argv Passed as-is to `func`.
*/
void ruby_each_words(const char *str, void (*func)(const char *word, int len, void *argv), void *argv);
RBIMPL_SYMBOL_EXPORT_END()
#endif /* RUBY_UTIL_H */