Use C99-defined macros to classify a floating-point number

LEGAL

@@ -532,10 +532,7 @@ mentioned below.
 [missing/acosh.c]
 [missing/alloca.c]
 [missing/erf.c]
-[missing/finite.c]
 [missing/hypot.c]
-[missing/isinf.c]
-[missing/isnan.c]
 [missing/lgamma_r.c]
 [missing/memcmp.c]
 [missing/memmove.c]

bignum.c

@@ -5382,7 +5382,7 @@ rb_integer_float_eq(VALUE x, VALUE y)
     double yd = RFLOAT_VALUE(y);
     double yi, yf;
 
-    if (isnan(yd) || isinf(yd))
+    if (!isfinite(yd))
         return Qfalse;
     yf = modf(yd, &yi);
     if (yf != 0)

common.mk

@@ -963,7 +963,6 @@ crypt.$(OBJEXT): {$(VPATH)}crypt.c {$(VPATH)}crypt.h {$(VPATH)}missing/des_table
 dup2.$(OBJEXT): {$(VPATH)}dup2.c
 erf.$(OBJEXT): {$(VPATH)}erf.c
 explicit_bzero.$(OBJEXT): {$(VPATH)}explicit_bzero.c
-finite.$(OBJEXT): {$(VPATH)}finite.c
 flock.$(OBJEXT): {$(VPATH)}flock.c
 memcmp.$(OBJEXT): {$(VPATH)}memcmp.c
 memmove.$(OBJEXT): {$(VPATH)}memmove.c

configure.ac

@@ -799,7 +799,7 @@ AS_IF([test "$GCC" = yes], [
       ])
     ],
     [cygwin*|msys*|darwin*|netbsd*], [
-      # need lgamma_r(), finite()
+      # need lgamma_r()
     ])
 
     # ANSI (no XCFLAGS because this is C only)
@@ -1906,9 +1906,7 @@ AC_REPLACE_FUNCS(strlcpy)
 AC_REPLACE_FUNCS(strstr)
 AC_REPLACE_FUNCS(tgamma)
 
-RUBY_REPLACE_FUNC([finite], [@%:@include <math.h>])
-RUBY_REPLACE_FUNC([isinf], [@%:@include <math.h>])
-RUBY_REPLACE_FUNC([isnan], [@%:@include <math.h>])
+AC_DEFINE(HAVE_ISFINITE)        # C99; backward compatibility
 
 # for missing/setproctitle.c
 AS_CASE(["$target_os"],

include/ruby/missing.h

@@ -92,10 +92,6 @@ RUBY_EXTERN int eaccess(const char*, int);
 RUBY_EXTERN double round(double);	/* numeric.c */
 #endif
 
-#ifndef HAVE_FINITE
-RUBY_EXTERN int finite(double);
-#endif
-
 #ifndef HAVE_FLOCK
 RUBY_EXTERN int flock(int, int);
 #endif
@@ -152,35 +148,9 @@ RUBY_EXTERN const union bytesequence4_or_float rb_nan;
 # define HUGE_VAL ((double)INFINITY)
 #endif
 
-#if defined(isinf)
-# /* Take that. */
-#elif defined(HAVE_ISINF)
-# /* Take that. */
-#elif defined(HAVE_FINITE) && defined(HAVE_ISNAN)
-# define isinf(x) (!finite(x) && !isnan(x))
-#elif defined(__cplusplus) && __cplusplus >= 201103L
-# // <cmath> must include constexpr bool isinf(double);
-#else
-RUBY_EXTERN int isinf(double);
-#endif
-
-#if defined(isnan)
-# /* Take that. */
-#elif defined(HAVE_ISNAN)
-# /* Take that. */
-#elif defined(__cplusplus) && __cplusplus >= 201103L
-# // <cmath> must include constexpr bool isnan(double);
-#else
-RUBY_EXTERN int isnan(double);
-#endif
-
-#if defined(isfinite)
-# /* Take that. */
-#elif defined(HAVE_ISFINITE)
-# /* Take that. */
-#else
-# define HAVE_ISFINITE 1
-# define isfinite(x) finite(x)
+#ifndef HAVE_FINITE
+# define HAVE_FINITE 1
+# define finite(x) isfinite(x)
 #endif
 
 #ifndef HAVE_NAN

include/ruby/win32.h

@@ -343,14 +343,6 @@ rb_infinity_float(void)
 #endif
 
 #if !defined __MINGW32__ || defined __NO_ISOCEXT
-#ifndef isnan
-#define isnan(x) _isnan(x)
-#endif
-static inline int
-finite(double x)
-{
-    return _finite(x);
-}
 #ifndef copysign
 #define copysign(a, b) _copysign(a, b)
 #endif
@@ -359,8 +351,6 @@ scalb(double a, long b)
 {
     return _scalb(a, b);
 }
-#else
-__declspec(dllimport) extern int finite(double);
 #endif
 
 #if !defined S_IFIFO && defined _S_IFIFO

missing/erf.c

@@ -7,21 +7,6 @@ reference - Haruhiko Okumura: C-gengo niyoru saishin algorithm jiten
 #include <stdio.h>
 #include <math.h>
 
-#ifdef _WIN32
-# include <float.h>
-# if !defined __MINGW32__ || defined __NO_ISOCEXT
-#  ifndef isnan
-#   define isnan(x) _isnan(x)
-#  endif
-#  ifndef isinf
-#   define isinf(x) (!_finite(x) && !_isnan(x))
-#  endif
-#  ifndef finite
-#   define finite(x) _finite(x)
-#  endif
-# endif
-#endif
-
 static double q_gamma(double, double, double);
 
 /* Incomplete gamma function

missing/tgamma.c

@@ -14,21 +14,6 @@ reference - Haruhiko Okumura: C-gengo niyoru saishin algorithm jiten
 #include <math.h>
 #include <errno.h>
 
-#ifdef _WIN32
-# include <float.h>
-# if !defined __MINGW32__ || defined __NO_ISOCEXT
-#  ifndef isnan
-#   define isnan(x) _isnan(x)
-#  endif
-#  ifndef isinf
-#   define isinf(x) (!_finite(x) && !_isnan(x))
-#  endif
-#  ifndef finite
-#   define finite(x) _finite(x)
-#  endif
-# endif
-#endif
-
 #ifndef HAVE_LGAMMA_R
 
 #include <errno.h>

numeric.c

@@ -1699,15 +1699,7 @@ rb_flo_is_finite_p(VALUE num)
 {
     double value = RFLOAT_VALUE(num);
 
-#ifdef HAVE_ISFINITE
-    if (!isfinite(value))
-	return Qfalse;
-#else
-    if (isinf(value) || isnan(value))
-	return Qfalse;
-#endif
-
-    return Qtrue;
+    return RBOOL(isfinite(value));
 }
 
 static VALUE

random.c

@@ -1348,7 +1348,7 @@ static inline double
 float_value(VALUE v)
 {
     double x = RFLOAT_VALUE(v);
-    if (isinf(x) || isnan(x)) {
+    if (!isfinite(x)) {
 	domain_error();
     }
     return x;

rational.c

@@ -2096,7 +2096,7 @@ rb_float_numerator(VALUE self)
 {
     double d = RFLOAT_VALUE(self);
     VALUE r;
-    if (isinf(d) || isnan(d))
+    if (!isfinite(d))
 	return self;
     r = float_to_r(self);
     return nurat_numerator(r);
@@ -2116,7 +2116,7 @@ rb_float_denominator(VALUE self)
 {
     double d = RFLOAT_VALUE(self);
     VALUE r;
-    if (isinf(d) || isnan(d))
+    if (!isfinite(d))
 	return INT2FIX(1);
     r = float_to_r(self);
     return nurat_denominator(r);

sprintf.c

@@ -875,7 +875,7 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
 		double fval;
 
 		fval = RFLOAT_VALUE(rb_Float(val));
-		if (isnan(fval) || isinf(fval)) {
+		if (!isfinite(fval)) {
 		    const char *expr;
 		    int need;
 		    int elen;