limits.c.tmpl

%#  -*- c -*-
% limits = %w[
%   FIXNUM
%   CHAR   SCHAR   UCHAR  WCHAR
%          SHRT    USHRT
%          INT     UINT
%          LONG    ULONG
%          LLONG   ULLONG
%          INT8    UINT8  INT_LEAST8  UINT_LEAST8  INT_FAST8  UINT_FAST8
%          INT16   UINT16 INT_LEAST16 UINT_LEAST16 INT_FAST16 UINT_FAST16
%          INT32   UINT32 INT_LEAST32 UINT_LEAST32 INT_FAST32 UINT_FAST32
%          INT64   UINT64 INT_LEAST64 UINT_LEAST64 INT_FAST64 UINT_FAST64
%          INT128  UINT128
%          INTMAX  UINTMAX
%          INTPTR  UINTPTR
%          SSZIE   SIZE
%          PTRDIFF
% ]
%
% verbatim_integers = %w[
%   FLT_RADIX
%   FLT_ROUNDS
%   FLT_EVAL_METHOD
%   FLT_MANT_DIG    DBL_MANT_DIG    LDBL_MANT_DIG
%   FLT_DIG         DBL_DIG         LDBL_DIG
%   FLT_MIN_EXP     DBL_MIN_EXP     LDBL_MIN_EXP
%   FLT_MIN_10_EXP  DBL_MIN_10_EXP  LDBL_MIN_10_EXP
%   FLT_MAX_EXP     DBL_MAX_EXP     LDBL_MAX_EXP
%   FLT_MAX_10_EXP  DBL_MAX_10_EXP  LDBL_MAX_10_EXP
%   FLT_DECIMAL_DIG DBL_DECIMAL_DIG LDBL_DECIMAL_DIG DECIMAL_DIG
%   FLT_HAS_SUBNORM DBL_HAS_SUBNORM LDBL_HAS_SUBNORM
% ]
%
% # Beware; Ruby cannot handle LDBL_MAX.
% verbatim_doubles = %w[
%   FLT_MAX      DBL_MAX
%   FLT_EPSILON  DBL_EPSILON
%   FLT_MIN      DBL_MIN
%   FLT_TRUE_MIN DBL_TRUE_MIN
% ]
%
#include <limits.h>
#include "ruby/ruby.h"
#ifdef HAVE_STDINT_H
# include <stdint.h>
#endif
#ifdef HAVE_INTTYPES_H
# include <stdint.h>
#endif
#ifdef HAVE_FLOAT_H
# include <float.h>
#endif

/*
 * Document-const: LIMITS
 *
 * A Hash with the bounds of numeric types available to the \C compiler
 * used to build Ruby. To access this constant, first run
 * <code>require 'rbconfig/sizeof'</code>.
 *
 *    require 'rbconfig/sizeof'
 *    RUBY_PLATFORM # => "x64-mingw-ucrt"
 *    RbConfig::LIMITS.fetch_values('FIXNUM_MAX', 'LONG_MAX')
 *    # => [1073741823, 2147483647]
 *
 */

void
Init_limits(void)
{
    VALUE h = rb_hash_new();
    VALUE mRbConfig = rb_define_module("RbConfig");
    rb_define_const(mRbConfig, "LIMITS", h);

#ifdef HAVE_LONG_LONG
#ifndef ULLONG_MAX
#define ULLONG_MAX ((unsigned LONG_LONG)LLONG_MAX*2+1)
#endif
#define MAX2NUM(name) ULL2NUM(name ## _MAX)
#define MIN2NUM(name)  LL2NUM(name ## _MIN)
#else
#define MAX2NUM(name) ULONG2NUM(name ## _MAX)
#define MIN2NUM(name)  LONG2NUM(name ## _MIN)
#endif
#define DEFINE(k, v) rb_hash_aset(h, rb_usascii_str_new_lit(#k), v)

% limits.each do |type|
#ifdef <%= type %>_MAX
    DEFINE(<%= type %>_MAX, MAX2NUM(<%= type %>));
#endif
#ifdef <%= type %>_MIN
    DEFINE(<%= type %>_MIN, MIN2NUM(<%= type %>));
#endif
% end

% verbatim_integers.each do |name|
#ifdef <%= name %>
    DEFINE(<%= name %>, LONG2NUM(<%= name %>));
#endif
% end

% verbatim_doubles.each do |name|
#ifdef <%= name %>
    DEFINE(<%= name %>, DBL2NUM(<%= name %>));
#endif
% end

#undef DEFINE
#undef MIN2NUM
#undef MAX2NUM
    OBJ_FREEZE(h);
}