bpo-28180: Implementation for PEP 538 (#659)

- new PYTHONCOERCECLOCALE config setting
- coerces legacy C locale to C.UTF-8, C.utf8 or UTF-8 by default
- always uses C.UTF-8 on Android
- uses `surrogateescape` on stdin and stdout in the coercion
  target locales
- configure option to disable locale coercion at build time
- configure option to disable C locale warning at build time

1 files changed, 34 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index d5b6399..18b940a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3325,6 +3325,40 @@ then
 fi
 AC_MSG_RESULT($with_pymalloc)
 
+# Check for --with-c-locale-coercion
+AC_MSG_CHECKING(for --with-c-locale-coercion)
+AC_ARG_WITH(c-locale-coercion,
+            AS_HELP_STRING([--with(out)-c-locale-coercion],
+              [disable/enable C locale coercion to a UTF-8 based locale]))
+
+if test -z "$with_c_locale_coercion"
+then
+    with_c_locale_coercion="yes"
+fi
+if test "$with_c_locale_coercion" != "no"
+then
+    AC_DEFINE(PY_COERCE_C_LOCALE, 1,
+      [Define if you want to coerce the C locale to a UTF-8 based locale])
+fi
+AC_MSG_RESULT($with_c_locale_coercion)
+
+# Check for --with-c-locale-warning
+AC_MSG_CHECKING(for --with-c-locale-warning)
+AC_ARG_WITH(c-locale-warning,
+            AS_HELP_STRING([--with(out)-c-locale-warning],
+              [disable/enable locale compatibility warning in the C locale]))
+
+if test -z "$with_c_locale_warning"
+then
+    with_c_locale_warning="yes"
+fi
+if test "$with_c_locale_warning" != "no"
+then
+    AC_DEFINE(PY_WARN_ON_C_LOCALE, 1,
+      [Define to emit a locale compatibility warning in the C locale])
+fi
+AC_MSG_RESULT($with_c_locale_warning)
+
 # Check for Valgrind support
 AC_MSG_CHECKING([for --with-valgrind])
 AC_ARG_WITH([valgrind],