bpo-32230: Set sys.warnoptions with -X dev (#4820)

Rather than supporting dev mode directly in the warnings module, this
instead adjusts the initialisation code to add an extra 'default'
entry to sys.warnoptions when dev mode is enabled.

This ensures that dev mode behaves *exactly* as if `-Wdefault` had
been passed on the command line, including in the way it interacts
with `sys.warnoptions`, and with other command line flags like `-bb`.

Fix also bpo-20361: have -b & -bb options take precedence over any
other warnings options.

Patch written by Nick Coghlan, with minor modifications of Victor Stinner.
This commit is contained in:
Victor Stinner 2017-12-12 22:59:48 +01:00 committed by GitHub
parent b748e3b258
commit 747f48e2e9
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GPG key ID: 4AEE18F83AFDEB23
12 changed files with 224 additions and 124 deletions

View file

@ -774,11 +774,73 @@ pymain_add_warnings_optlist(_Py_OptList *warnings)
return 0;
}
static int
pymain_add_warning_dev_mode(_PyCoreConfig *core_config)
{
if (core_config->dev_mode) {
PyObject *option = PyUnicode_FromString("default");
if (option == NULL) {
return -1;
}
if (_PySys_AddWarnOptionWithError(option)) {
Py_DECREF(option);
return -1;
}
Py_DECREF(option);
}
return 0;
}
static int
pymain_add_warning_bytes_flag(int bytes_warning_flag)
{
/* If the bytes_warning_flag isn't set, bytesobject.c and bytearrayobject.c
* don't even try to emit a warning, so we skip setting the filter in that
* case.
*/
if (bytes_warning_flag) {
const char *filter = (bytes_warning_flag > 1) ? "error::BytesWarning":
"default::BytesWarning";
PyObject *option = PyUnicode_FromString(filter);
if (option == NULL) {
return -1;
}
if (_PySys_AddWarnOptionWithError(option)) {
Py_DECREF(option);
return -1;
}
Py_DECREF(option);
}
return 0;
}
static int
pymain_add_warnings_options(_PyMain *pymain)
{
PySys_ResetWarnOptions();
/* The priority order for warnings configuration is (highest precedence
* first):
*
* - the BytesWarning filter, if needed ('-b', '-bb')
* - any '-W' command line options; then
* - the 'PYTHONWARNINGS' environment variable; then
* - the dev mode filter ('-X dev', 'PYTHONDEVMODE'); then
* - any implicit filters added by _warnings.c/warnings.py
*
* All settings except the last are passed to the warnings module via
* the `sys.warnoptions` list. Since the warnings module works on the basis
* of "the most recently added filter will be checked first", we add
* the lowest precedence entries first so that later entries override them.
*/
if (pymain_add_warning_dev_mode(&pymain->core_config) < 0) {
pymain->err = _Py_INIT_NO_MEMORY();
return -1;
}
if (pymain_add_warnings_optlist(&pymain->env_warning_options) < 0) {
pymain->err = _Py_INIT_NO_MEMORY();
return -1;
@ -787,6 +849,10 @@ pymain_add_warnings_options(_PyMain *pymain)
pymain->err = _Py_INIT_NO_MEMORY();
return -1;
}
if (pymain_add_warning_bytes_flag(pymain->cmdline.bytes_warning) < 0) {
pymain->err = _Py_INIT_NO_MEMORY();
return -1;
}
return 0;
}