bpo-43510: Implement PEP 597 opt-in EncodingWarning. (GH-19481)
See [PEP 597](https://www.python.org/dev/peps/pep-0597/).
* Add `-X warn_default_encoding` and `PYTHONWARNDEFAULTENCODING`.
* Add EncodingWarning
* Add io.text_encoding()
* open(), TextIOWrapper() emits EncodingWarning when encoding is omitted and warn_default_encoding is enabled.
* _pyio.TextIOWrapper() uses UTF-8 as fallback default encoding used when failed to import locale module. (used during building Python)
* bz2, configparser, gzip, lzma, pathlib, tempfile modules use io.text_encoding().
* What's new entry
diff --git a/Include/cpython/initconfig.h b/Include/cpython/initconfig.h
index 666c1e4..09f9a29 100644
--- a/Include/cpython/initconfig.h
+++ b/Include/cpython/initconfig.h
@@ -153,6 +153,7 @@ typedef struct PyConfig {
PyWideStringList warnoptions;
int site_import;
int bytes_warning;
+ int warn_default_encoding;
int inspect;
int interactive;
int optimization_level;
diff --git a/Include/internal/pycore_initconfig.h b/Include/internal/pycore_initconfig.h
index 28cd570..4b009e8 100644
--- a/Include/internal/pycore_initconfig.h
+++ b/Include/internal/pycore_initconfig.h
@@ -102,6 +102,7 @@ typedef struct {
int isolated; /* -I option */
int use_environment; /* -E option */
int dev_mode; /* -X dev and PYTHONDEVMODE */
+ int warn_default_encoding; /* -X warn_default_encoding and PYTHONWARNDEFAULTENCODING */
} _PyPreCmdline;
#define _PyPreCmdline_INIT \
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 14129d3..f5d1c71 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -146,6 +146,7 @@ PyAPI_DATA(PyObject *) PyExc_FutureWarning;
PyAPI_DATA(PyObject *) PyExc_ImportWarning;
PyAPI_DATA(PyObject *) PyExc_UnicodeWarning;
PyAPI_DATA(PyObject *) PyExc_BytesWarning;
+PyAPI_DATA(PyObject *) PyExc_EncodingWarning;
PyAPI_DATA(PyObject *) PyExc_ResourceWarning;