bpo-34523: Add _PyCoreConfig.filesystem_encoding (GH-8963)

_PyCoreConfig_Read() is now responsible to choose the filesystem
encoding and error handler. Using Py_Main(), the encoding is now
chosen even before calling Py_Initialize().

_PyCoreConfig.filesystem_encoding is now the reference, instead of
Py_FileSystemDefaultEncoding, for the Python filesystem encoding.

Changes:

* Add filesystem_encoding and filesystem_errors to _PyCoreConfig
* _PyCoreConfig_Read() now reads the locale encoding for the file
  system encoding.
* PyUnicode_EncodeFSDefault() and PyUnicode_DecodeFSDefaultAndSize()
  now use the interpreter configuration rather than
  Py_FileSystemDefaultEncoding and Py_FileSystemDefaultEncodeErrors
  global configuration variables.
* Add _Py_SetFileSystemEncoding() and _Py_ClearFileSystemEncoding()
  private functions to only modify Py_FileSystemDefaultEncoding and
  Py_FileSystemDefaultEncodeErrors in coreconfig.c.
* _Py_CoerceLegacyLocale() now takes an int rather than
  _PyCoreConfig for the warning.

1 files changed, 30 insertions, 12 deletions

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 177b830..91df4b0 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -389,11 +389,9 @@ implementation."
 static PyObject *
 sys_getfilesystemencoding(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
-    if (Py_FileSystemDefaultEncoding)
-        return PyUnicode_FromString(Py_FileSystemDefaultEncoding);
-    PyErr_SetString(PyExc_RuntimeError,
-                    "filesystem encoding is not initialized");
-    return NULL;
+    PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
+    const _PyCoreConfig *config = &interp->core_config;
+    return PyUnicode_FromString(config->filesystem_encoding);
 }
 
 PyDoc_STRVAR(getfilesystemencoding_doc,
@@ -406,11 +404,9 @@ operating system filenames."
 static PyObject *
 sys_getfilesystemencodeerrors(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
-    if (Py_FileSystemDefaultEncodeErrors)
-        return PyUnicode_FromString(Py_FileSystemDefaultEncodeErrors);
-    PyErr_SetString(PyExc_RuntimeError,
-        "filesystem encoding is not initialized");
-    return NULL;
+    PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
+    const _PyCoreConfig *config = &interp->core_config;
+    return PyUnicode_FromString(config->filesystem_errors);
 }
 
 PyDoc_STRVAR(getfilesystemencodeerrors_doc,
@@ -1150,8 +1146,30 @@ environment variable before launching Python."
 static PyObject *
 sys_enablelegacywindowsfsencoding(PyObject *self)
 {
-    Py_FileSystemDefaultEncoding = "mbcs";
-    Py_FileSystemDefaultEncodeErrors = "replace";
+    PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
+    _PyCoreConfig *config = &interp->core_config;
+
+    /* Set the filesystem encoding to mbcs/replace (PEP 529) */
+    char *encoding = _PyMem_RawStrdup("mbcs");
+    char *errors = _PyMem_RawStrdup("replace");
+    if (encoding == NULL || errors == NULL) {
+        PyMem_Free(encoding);
+        PyMem_Free(errors);
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    PyMem_RawFree(config->filesystem_encoding);
+    config->filesystem_encoding = encoding;
+    PyMem_RawFree(config->filesystem_errors);
+    config->filesystem_errors = errors;
+
+    if (_Py_SetFileSystemEncoding(config->filesystem_encoding,
+                                  config->filesystem_errors) < 0) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+
     Py_RETURN_NONE;
 }