bpo-45412: Move copysign() define to pycore_pymath.h (GH-28889)

Move definitions of copysign(), round(), hypot(), fmod(), etc. from
pymath.h to pycore_pymath.h. These functions are not exported by
libpython and so must not be part of the C API.

Include/internal/pycore_pymath.h

@@ -8,6 +8,34 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+
+// Python provides implementations for copysign(), round() and hypot() in
+// Python/pymath.c just in case your math library doesn't provide the
+// functions.
+//
+// Note: PC/pyconfig.h defines copysign as _copysign
+#ifndef HAVE_COPYSIGN
+extern double copysign(double, double);
+#endif
+
+#ifndef HAVE_ROUND
+extern double round(double);
+#endif
+
+#ifndef HAVE_HYPOT
+extern double hypot(double, double);
+#endif
+
+// Extra declarations
+#if !defined(_MSC_VER) && !defined(__STDC__)
+extern double fmod (double, double);
+extern double frexp (double, int *);
+extern double ldexp (double, int);
+extern double modf (double, double *);
+extern double pow(double, double);
+#endif  // !defined(_MSC_VER) && !defined(__STDC__)
+
+
 /* _Py_ADJUST_ERANGE1(x)
  * _Py_ADJUST_ERANGE2(x, y)
  * Set errno to 0 before calling a libm function, and invoke one of these

Include/pymath.h

@@ -1,41 +1,10 @@
+// Symbols and macros to supply platform-independent interfaces to mathematical
+// functions and constants.
+
 #ifndef Py_PYMATH_H
 #define Py_PYMATH_H
 
-#include "pyconfig.h" /* include for defines */
+#include "pyconfig.h"             // HAVE_DECL_ISNAN
-
-/**************************************************************************
-Symbols and macros to supply platform-independent interfaces to mathematical
-functions and constants
-**************************************************************************/
-
-/* Python provides implementations for copysign, round and hypot in
- * Python/pymath.c just in case your math library doesn't provide the
- * functions.
- *
- *Note: PC/pyconfig.h defines copysign as _copysign
- */
-#ifndef HAVE_COPYSIGN
-extern double copysign(double, double);
-#endif
-
-#ifndef HAVE_ROUND
-extern double round(double);
-#endif
-
-#ifndef HAVE_HYPOT
-extern double hypot(double, double);
-#endif
-
-/* extra declarations */
-#ifndef _MSC_VER
-#ifndef __STDC__
-extern double fmod (double, double);
-extern double frexp (double, int *);
-extern double ldexp (double, int);
-extern double modf (double, double *);
-extern double pow(double, double);
-#endif /* __STDC__ */
-#endif /* _MSC_VER */
 
 /* High precision definition of pi and e (Euler)
  * The values are taken from libc6's math.h.
@@ -123,13 +92,13 @@ PyAPI_FUNC(double) _Py_force_double(double);
  * Note: PC/pyconfig.h defines Py_IS_FINITE as _finite
  */
 #ifndef Py_IS_FINITE
-#if defined HAVE_DECL_ISFINITE && HAVE_DECL_ISFINITE == 1
+#  if defined HAVE_DECL_ISFINITE && HAVE_DECL_ISFINITE == 1
-#define Py_IS_FINITE(X) isfinite(X)
+#    define Py_IS_FINITE(X) isfinite(X)
-#elif defined HAVE_FINITE
+#  elif defined HAVE_FINITE
-#define Py_IS_FINITE(X) finite(X)
+#    define Py_IS_FINITE(X) finite(X)
-#else
+#  else
-#define Py_IS_FINITE(X) (!Py_IS_INFINITY(X) && !Py_IS_NAN(X))
+#    define Py_IS_FINITE(X) (!Py_IS_INFINITY(X) && !Py_IS_NAN(X))
-#endif
+#  endif
 #endif
 
 /* HUGE_VAL is supposed to expand to a positive double infinity.  Python
@@ -140,7 +109,7 @@ PyAPI_FUNC(double) _Py_force_double(double);
  * config to #define Py_HUGE_VAL to something that works on your platform.
  */
 #ifndef Py_HUGE_VAL
-#define Py_HUGE_VAL HUGE_VAL
+#  define Py_HUGE_VAL HUGE_VAL
 #endif
 
 /* Py_NAN
@@ -149,10 +118,10 @@ PyAPI_FUNC(double) _Py_force_double(double);
  * doesn't support NaNs.
  */
 #if !defined(Py_NAN) && !defined(Py_NO_NAN)
-#if !defined(__INTEL_COMPILER)
+#  if !defined(__INTEL_COMPILER)
-    #define Py_NAN (Py_HUGE_VAL * 0.)
+#    define Py_NAN (Py_HUGE_VAL * 0.)
-#else /* __INTEL_COMPILER */
+#  else /* __INTEL_COMPILER */
-    #if defined(ICC_NAN_STRICT)
+#    if defined(ICC_NAN_STRICT)
         #pragma float_control(push)
         #pragma float_control(precise, on)
         #pragma float_control(except,  on)
@@ -161,12 +130,12 @@ PyAPI_FUNC(double) _Py_force_double(double);
             return sqrt(-1.0);
         }
         #pragma float_control (pop)
-        #define Py_NAN __icc_nan()
+#       define Py_NAN __icc_nan()
-    #else /* ICC_NAN_RELAXED as default for Intel Compiler */
+#    else /* ICC_NAN_RELAXED as default for Intel Compiler */
         static const union { unsigned char buf[8]; double __icc_nan; } __nan_store = {0,0,0,0,0,0,0xf8,0x7f};
-        #define Py_NAN (__nan_store.__icc_nan)
+#       define Py_NAN (__nan_store.__icc_nan)
-    #endif /* ICC_NAN_STRICT */
+#    endif /* ICC_NAN_STRICT */
-#endif /* __INTEL_COMPILER */
+#  endif /* __INTEL_COMPILER */
 #endif
 
 #endif /* Py_PYMATH_H */