Issue python#17594: MINGW: preset configure defaults

Misc/config_mingw

@@ -0,0 +1,12 @@
+# configure defaults for mingw* hosts
+
+# mingw functions to ignore
+ac_cv_func_ftruncate=ignore	# implement it as _chsize
+
+# mingw-w64 functions to ignore
+ac_cv_func_truncate=ignore
+ac_cv_func_alarm=ignore
+
+# files to ignore
+ac_cv_file__dev_ptmx=ignore #NOTE: under MSYS environment device exist
+ac_cv_file__dev_ptc=no

Misc/cross_mingw32

@@ -0,0 +1,11 @@
+# configure defaults for mingw32 host if cross-build
+
+ac_cv_little_endian_double=yes
+ac_cv_big_endian_double=no
+ac_cv_mixed_endian_double=no
+
+ac_cv_tanh_preserves_zero_sign=yes
+
+ac_cv_wchar_t_signed=no
+
+ac_cv_have_size_t_format=no

configure.ac

@@ -747,6 +747,28 @@ fi
 MULTIARCH=$($CC --print-multiarch 2>/dev/null)
 AC_SUBST(MULTIARCH)
 
+# initialize default configuration
+py_config=
+case $host in
+  *-*-mingw*) py_config=mingw ;;
+esac
+if test -n "$py_config" ; then
+  AC_MSG_NOTICE([loading configure defaults from .../Misc/config_$py_config"])
+  . "$srcdir/Misc/config_$py_config"
+fi
+
+# initialize defaults for cross-builds
+if test "$cross_compiling" = yes; then
+  py_config=$host_os
+  case $py_config in
+    mingw32*) py_config=mingw32 ;;
+  esac
+  if test -f "$srcdir/Misc/cross_$py_config" ; then
+    AC_MSG_NOTICE([loading cross defaults from .../Misc/cross_$py_config"])
+    . "$srcdir/Misc/cross_$py_config"
+  fi
+fi
+
 AC_MSG_CHECKING([for the platform triplet based on compiler characteristics])
 cat >> conftest.c <<EOF
 #undef bfin