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Diffstat (limited to 'include/ruby/internal/special_consts.h')
| -rw-r--r-- | include/ruby/internal/special_consts.h | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/include/ruby/internal/special_consts.h b/include/ruby/internal/special_consts.h new file mode 100644 index 0000000000..1e2636da48 --- /dev/null +++ b/include/ruby/internal/special_consts.h @@ -0,0 +1,362 @@ +#ifndef RBIMPL_SPECIAL_CONSTS_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RBIMPL_SPECIAL_CONSTS_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 `RBIMPL` or `rbimpl` 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 Defines enum ::ruby_special_consts. + * @see Sasada, K., "A Lightweight Representation of Floating-Point + * Numbers on Ruby Interpreter", in proceedings of 10th JSSST + * SIGPPL Workshop on Programming and Programming Languages + * (PPL2008), pp. 9-16, 2008. + */ +#include "ruby/internal/attr/artificial.h" +#include "ruby/internal/attr/const.h" +#include "ruby/internal/attr/constexpr.h" +#include "ruby/internal/attr/enum_extensibility.h" +#include "ruby/internal/stdbool.h" +#include "ruby/internal/value.h" + +/** + * @private + * @warning Do not touch this macro. + * @warning It is an implementation detail. + * @warning The value of this macro must match for ruby itself and all + * extension libraries, otherwise serious memory corruption shall + * occur. + */ +#if defined(USE_FLONUM) +# /* Take that. */ +#elif SIZEOF_VALUE >= SIZEOF_DOUBLE +# define USE_FLONUM 1 +#else +# define USE_FLONUM 0 +#endif + +/** This is an old name of #RB_TEST. Not sure which name is preferred. */ +#define RTEST RB_TEST + +#define FIXNUM_P RB_FIXNUM_P /**< @old{RB_FIXNUM_P} */ +#define IMMEDIATE_P RB_IMMEDIATE_P /**< @old{RB_IMMEDIATE_P} */ +#define NIL_P RB_NIL_P /**< @old{RB_NIL_P} */ +#define SPECIAL_CONST_P RB_SPECIAL_CONST_P /**< @old{RB_SPECIAL_CONST_P} */ +#define STATIC_SYM_P RB_STATIC_SYM_P /**< @old{RB_STATIC_SYM_P} */ + +#define Qfalse RUBY_Qfalse /**< @old{RUBY_Qfalse} */ +#define Qnil RUBY_Qnil /**< @old{RUBY_Qnil} */ +#define Qtrue RUBY_Qtrue /**< @old{RUBY_Qtrue} */ +#define Qundef RUBY_Qundef /**< @old{RUBY_Qundef} */ + +#define FIXNUM_FLAG RUBY_FIXNUM_FLAG /**< @old{RUBY_FIXNUM_FLAG} */ +#define FLONUM_FLAG RUBY_FLONUM_FLAG /**< @old{RUBY_FLONUM_FLAG} */ +#define FLONUM_MASK RUBY_FLONUM_MASK /**< @old{RUBY_FLONUM_MASK} */ +#define FLONUM_P RB_FLONUM_P /**< @old{RB_FLONUM_P} */ +#define IMMEDIATE_MASK RUBY_IMMEDIATE_MASK /**< @old{RUBY_IMMEDIATE_MASK} */ +#define SYMBOL_FLAG RUBY_SYMBOL_FLAG /**< @old{RUBY_SYMBOL_FLAG} */ + +/** @cond INTERNAL_MACRO */ +#define RB_FIXNUM_P RB_FIXNUM_P +#define RB_FLONUM_P RB_FLONUM_P +#define RB_IMMEDIATE_P RB_IMMEDIATE_P +#define RB_NIL_P RB_NIL_P +#define RB_SPECIAL_CONST_P RB_SPECIAL_CONST_P +#define RB_STATIC_SYM_P RB_STATIC_SYM_P +#define RB_TEST RB_TEST +#define RB_UNDEF_P RB_UNDEF_P +#define RB_NIL_OR_UNDEF_P RB_NIL_OR_UNDEF_P +/** @endcond */ + +/** special constants - i.e. non-zero and non-fixnum constants */ +enum +RBIMPL_ATTR_ENUM_EXTENSIBILITY(closed) +ruby_special_consts { +#if defined(__DOXYGEN__) + RUBY_Qfalse, /**< @see ::rb_cFalseClass */ + RUBY_Qtrue, /**< @see ::rb_cTrueClass */ + RUBY_Qnil, /**< @see ::rb_cNilClass */ + RUBY_Qundef, /**< Represents so-called undef. */ + RUBY_IMMEDIATE_MASK, /**< Bit mask detecting special consts. */ + RUBY_FIXNUM_FLAG, /**< Flag to denote a fixnum. */ + RUBY_FLONUM_MASK, /**< Bit mask detecting a flonum. */ + RUBY_FLONUM_FLAG, /**< Flag to denote a flonum. */ + RUBY_SYMBOL_FLAG, /**< Flag to denote a static symbol. */ +#elif USE_FLONUM + RUBY_Qfalse = 0x00, /* ...0000 0000 */ + RUBY_Qnil = 0x04, /* ...0000 0100 */ + RUBY_Qtrue = 0x14, /* ...0001 0100 */ + RUBY_Qundef = 0x24, /* ...0010 0100 */ + RUBY_IMMEDIATE_MASK = 0x07, /* ...0000 0111 */ + RUBY_FIXNUM_FLAG = 0x01, /* ...xxxx xxx1 */ + RUBY_FLONUM_MASK = 0x03, /* ...0000 0011 */ + RUBY_FLONUM_FLAG = 0x02, /* ...xxxx xx10 */ + RUBY_SYMBOL_FLAG = 0x0c, /* ...xxxx 1100 */ +#else + RUBY_Qfalse = 0x00, /* ...0000 0000 */ + RUBY_Qnil = 0x02, /* ...0000 0010 */ + RUBY_Qtrue = 0x06, /* ...0000 0110 */ + RUBY_Qundef = 0x0a, /* ...0000 1010 */ + RUBY_IMMEDIATE_MASK = 0x03, /* ...0000 0011 */ + RUBY_FIXNUM_FLAG = 0x01, /* ...xxxx xxx1 */ + RUBY_FLONUM_MASK = 0x00, /* any values ANDed with FLONUM_MASK cannot be FLONUM_FLAG */ + RUBY_FLONUM_FLAG = 0x02, /* ...0000 0010 */ + RUBY_SYMBOL_FLAG = 0x0e, /* ...xxxx 1110 */ +#endif + + RUBY_SPECIAL_SHIFT = 8 /**< Least significant 8 bits are reserved. */ +}; + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Emulates Ruby's "if" statement. + * + * @param[in] obj An arbitrary ruby object. + * @retval false `obj` is either ::RUBY_Qfalse or ::RUBY_Qnil. + * @retval true Anything else. + * + * @internal + * + * It HAS to be `__attribute__((const))` in order for clang to properly deduce + * `__builtin_assume()`. + */ +static inline bool +RB_TEST(VALUE obj) +{ + /* + * if USE_FLONUM + * Qfalse: ....0000 0000 + * Qnil: ....0000 0100 + * ~Qnil: ....1111 1011 + * v ....xxxx xxxx + * ---------------------------- + * RTEST(v) ....xxxx x0xx + * + * if ! USE_FLONUM + * Qfalse: ....0000 0000 + * Qnil: ....0000 0010 + * ~Qnil: ....1111 1101 + * v ....xxxx xxxx + * ---------------------------- + * RTEST(v) ....xxxx xx0x + * + * RTEST(v) can be 0 if and only if (v == Qfalse || v == Qnil). + */ + return obj & RBIMPL_CAST((VALUE)~RUBY_Qnil); +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is nil. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is ::RUBY_Qnil. + * @retval false Anything else. + */ +static inline bool +RB_NIL_P(VALUE obj) +{ + return obj == RUBY_Qnil; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is undef. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is ::RUBY_Qundef. + * @retval false Anything else. + */ +static inline bool +RB_UNDEF_P(VALUE obj) +{ + return obj == RUBY_Qundef; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX14) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is nil or undef. Can be used to see if + * a keyword argument is not given or given `nil`. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is ::RUBY_Qnil or ::RUBY_Qundef. + * @retval false Anything else. + */ +static inline bool +RB_NIL_OR_UNDEF_P(VALUE obj) +{ + /* + * if USE_FLONUM + * Qundef: ....0010 0100 + * Qnil: ....0000 0100 + * mask: ....1101 1111 + * common_bits: ....0000 0100 + * --------------------------------- + * Qnil & mask ....0000 0100 + * Qundef & mask ....0000 0100 + * + * if ! USE_FLONUM + * Qundef: ....0000 1010 + * Qnil: ....0000 0010 + * mask: ....1111 0111 + * common_bits: ....0000 0010 + * ---------------------------- + * Qnil & mask ....0000 0010 + * Qundef & mask ....0000 0010 + * + * NIL_OR_UNDEF_P(v) can be true only when v is Qundef or Qnil. + */ + const VALUE mask = RBIMPL_CAST((VALUE)~(RUBY_Qundef ^ RUBY_Qnil)); + const VALUE common_bits = RUBY_Qundef & RUBY_Qnil; + return (obj & mask) == common_bits; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is a so-called Fixnum. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is a Fixnum. + * @retval false Anything else. + * @note Fixnum was a thing in the 20th century, but it is rather an + * implementation detail today. + */ +static inline bool +RB_FIXNUM_P(VALUE obj) +{ + return obj & RUBY_FIXNUM_FLAG; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX14) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is a static symbol. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is a static symbol + * @retval false Anything else. + * @see RB_DYNAMIC_SYM_P() + * @see RB_SYMBOL_P() + * @note These days there are static and dynamic symbols, just like we + * once had Fixnum/Bignum back in the old days. + */ +static inline bool +RB_STATIC_SYM_P(VALUE obj) +{ + RBIMPL_ATTR_CONSTEXPR(CXX14) + const VALUE mask = ~(RBIMPL_VALUE_FULL << RUBY_SPECIAL_SHIFT); + return (obj & mask) == RUBY_SYMBOL_FLAG; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is a so-called Flonum. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is a Flonum. + * @retval false Anything else. + * @see RB_FLOAT_TYPE_P() + * @note These days there are Flonums and non-Flonum floats, just like we + * once had Fixnum/Bignum back in the old days. + */ +static inline bool +RB_FLONUM_P(VALUE obj) +{ +#if USE_FLONUM + return (obj & RUBY_FLONUM_MASK) == RUBY_FLONUM_FLAG; +#else + return false; +#endif +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is an immediate i.e. an object which has no + * corresponding storage inside of the object space. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is a Flonum. + * @retval false Anything else. + * @see RB_FLOAT_TYPE_P() + * @note The concept of "immediate" is purely C specific. + */ +static inline bool +RB_IMMEDIATE_P(VALUE obj) +{ + return obj & RUBY_IMMEDIATE_MASK; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Checks if the given object is of enum ::ruby_special_consts. + * + * @param[in] obj An arbitrary ruby object. + * @retval true `obj` is a special constant. + * @retval false Anything else. + */ +static inline bool +RB_SPECIAL_CONST_P(VALUE obj) +{ + return (obj == RUBY_Qfalse) || RB_IMMEDIATE_P(obj); +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +/** + * Identical to RB_SPECIAL_CONST_P, except it returns a ::VALUE. + * + * @param[in] obj An arbitrary ruby object. + * @retval RUBY_Qtrue `obj` is a special constant. + * @retval RUBY_Qfalse Anything else. + * + * @internal + * + * This function is to mimic old rb_special_const_p macro but have anyone + * actually used its return value? Wasn't it just something no one needed? + */ +static inline VALUE +rb_special_const_p(VALUE obj) +{ + return (unsigned int)RB_SPECIAL_CONST_P(obj) * RUBY_Qtrue; +} + +/** + * @cond INTERNAL_MACRO + * See [ruby-dev:27513] for the following macros. + */ +#define RUBY_Qfalse RBIMPL_CAST((VALUE)RUBY_Qfalse) +#define RUBY_Qtrue RBIMPL_CAST((VALUE)RUBY_Qtrue) +#define RUBY_Qnil RBIMPL_CAST((VALUE)RUBY_Qnil) +#define RUBY_Qundef RBIMPL_CAST((VALUE)RUBY_Qundef) +/** @endcond */ + +#endif /* RBIMPL_SPECIAL_CONSTS_H */ |