[PATCH v2] math: guard BSD finite/isinf/isnan functions properly in math.h

[Yaakov Selkowitz <yselkowi at redhat dot com>]

Now that we have properly functioning feature test macros, the BSD
floating-point classification functions can go into math.h instead of
the non-standard ieeefp.h, and not under the C99 guard:

http://man7.org/linux/man-pages/man3/finite.3.html

The isnan function was in earlier versions of SUS but removed starting with
POSIX.1-2001, compare:

http://pubs.opengroup.org/onlinepubs/007908799/xsh/math.h.html
http://pubs.opengroup.org/onlinepubs/009695399/basedefs/math.h.html

Note that the isinf and isnan functions (but not the variants) conflict
with functions by the same name in C++11, hence they (and only they)
need to be hidden:

https://sourceware.org/git/?p=glibc.git;a=commit;h=d9b965fa56350d6eea9f7f438a0714c7ffbb183f
https://sourceware.org/git/?p=glibc.git;a=commit;h=3c47c83a9730c20e602694505b9278c25637b0d0

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
---
 newlib/libc/include/ieeefp.h | 13 -------------
 newlib/libc/include/math.h   | 25 +++++++++++++++++++------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/newlib/libc/include/ieeefp.h b/newlib/libc/include/ieeefp.h
index 2ffa456..2c04284 100644
--- a/newlib/libc/include/ieeefp.h
+++ b/newlib/libc/include/ieeefp.h
@@ -241,19 +241,6 @@ typedef int fp_rdi;
 fp_rdi _EXFUN(fpgetroundtoi,(void));
 fp_rdi _EXFUN(fpsetroundtoi,(fp_rdi));
 
-#undef isnan
-#undef isinf
-
-int _EXFUN(isnan, (double));
-int _EXFUN(isinf, (double));
-int _EXFUN(finite, (double));
-
-
-
-int _EXFUN(isnanf, (float));
-int _EXFUN(isinff, (float));
-int _EXFUN(finitef, (float));
-
 #define __IEEE_DBL_EXPBIAS 1023
 #define __IEEE_FLT_EXPBIAS 127
 
diff --git a/newlib/libc/include/math.h b/newlib/libc/include/math.h
index e5d6123..798fc6d 100644
--- a/newlib/libc/include/math.h
+++ b/newlib/libc/include/math.h
@@ -137,6 +137,25 @@ extern double fmod _PARAMS((double, double));
 #endif /* ! defined (__math_68881) */
 #endif /* ! defined (_REENT_ONLY) */
 
+#if __MISC_VISIBLE
+extern int finite _PARAMS((double));
+extern int finitef _PARAMS((float));
+extern int finitel _PARAMS((long double));
+extern int isinff _PARAMS((float));
+extern int isnanf _PARAMS((float));
+#ifdef __CYGWIN__ /* not implemented in newlib yet */
+extern int isinfl _PARAMS((long double));
+extern int isnanl _PARAMS((long double));
+#endif
+#if !defined(__cplusplus) || __cplusplus < 201103L
+extern int isinf _PARAMS((double));
+#endif
+#endif /* __MISC_VISIBLE */
+#if (__MISC_VISIBLE || (__XSI_VISIBLE && __XSI_VISIBLE < 600)) \
+  && (!defined(__cplusplus) || __cplusplus < 201103L)
+extern int isnan _PARAMS((double));
+#endif
+
 #if __ISO_C_VISIBLE >= 1999
 /* ISO C99 types and macros. */
 
@@ -289,15 +308,10 @@ extern int __signbitd (double x);
                            fpclassify(__a) == FP_NAN || fpclassify(__b) == FP_NAN;}))
 #endif
 
-/* Non ANSI long double precision functions.  */
-
-extern int finitel _PARAMS((long double));
-
 /* Non ANSI double precision functions.  */
 
 extern double infinity _PARAMS((void));
 extern double nan _PARAMS((const char *));
-extern int finite _PARAMS((double));
 extern double copysign _PARAMS((double, double));
 extern double logb _PARAMS((double));
 extern int ilogb _PARAMS((double));
@@ -396,7 +410,6 @@ extern float fmaf _PARAMS((float, float, float));
 
 extern float infinityf _PARAMS((void));
 extern float nanf _PARAMS((const char *));
-extern int finitef _PARAMS((float));
 extern float copysignf _PARAMS((float, float));
 extern float logbf _PARAMS((float));
 extern int ilogbf _PARAMS((float));
-- 
2.7.4