pythongh-108765: Python.h no longer includes <ieeefp.h>

Remove also the HAVE_IEEEFP_H macro: remove ieeefp.h from the
AC_CHECK_HEADERS() check of configure.ac.

Doc/whatsnew/3.13.rst

@@ -915,6 +915,12 @@ New Features
 Porting to Python 3.13
 ----------------------
 
+* ``Python.h`` no longer includes the ``<ieeefp.h>`` standard header. It was
+  included for the ``finite()`` function which is now provided by the
+  ``<math.h>`` header. It should now be included explicitly if needed. Remove
+  also the ``HAVE_IEEEFP_H`` macro.
+  (Contributed by Victor Stinner in :gh:`108765`.)
+
 Deprecated
 ----------
 

Include/Python.h

@@ -20,6 +20,7 @@
 #include <ctype.h>                // tolower()
 #include <inttypes.h>             // uintptr_t
 #include <limits.h>               // INT_MAX
+#include <math.h>                 // HUGE_VAL
 #include <stdarg.h>               // va_list
 #include <wchar.h>                // wchar_t
 #ifdef HAVE_STDDEF_H

Include/pyport.h

@@ -184,12 +184,6 @@ typedef Py_ssize_t Py_ssize_clean_t;
 #  define Py_MEMCPY memcpy
 #endif
 
-#ifdef HAVE_IEEEFP_H
-#include <ieeefp.h>  /* needed for 'finite' declaration on some platforms */
-#endif
-
-#include <math.h> /* Moved here from the math section, before extern "C" */
-
 /********************************************
  * WRAPPER FOR <time.h> and/or <sys/time.h> *
  ********************************************/

Misc/NEWS.d/next/C API/2023-09-01-20-41-49.gh-issue-108765.5dXc1r.rst

@@ -0,0 +1,4 @@
+``Python.h`` no longer includes the ``<ieeefp.h>`` standard header. It was
+included for the ``finite()`` function which is now provided by the
+``<math.h>`` header. It should now be included explicitly if needed. Remove
+also the ``HAVE_IEEEFP_H`` macro. Patch by Victor Stinner.

configure.ac

@@ -2667,7 +2667,7 @@ AC_DEFINE([STDC_HEADERS], [1],
 # checks for header files
 AC_CHECK_HEADERS([ \
   alloca.h asm/types.h bluetooth.h conio.h direct.h dlfcn.h endian.h errno.h fcntl.h grp.h \
-  ieeefp.h io.h langinfo.h libintl.h libutil.h linux/auxvec.h sys/auxv.h linux/fs.h linux/limits.h linux/memfd.h \
+  io.h langinfo.h libintl.h libutil.h linux/auxvec.h sys/auxv.h linux/fs.h linux/limits.h linux/memfd.h \
   linux/random.h linux/soundcard.h \
   linux/tipc.h linux/wait.h netdb.h net/ethernet.h netinet/in.h netpacket/packet.h poll.h process.h pthread.h pty.h \
   sched.h setjmp.h shadow.h signal.h spawn.h stropts.h sys/audioio.h sys/bsdtty.h sys/devpoll.h \

pyconfig.h.in

@@ -607,9 +607,6 @@
 /* Define this if you have le64toh() */
 #undef HAVE_HTOLE64
 
-/* Define to 1 if you have the <ieeefp.h> header file. */
-#undef HAVE_IEEEFP_H
-
 /* Define to 1 if you have the `if_nameindex' function. */
 #undef HAVE_IF_NAMEINDEX