bpo-32101: Add PYTHONDEVMODE environment variable (#4624)

* bpo-32101: Add sys.flags.dev_mode flag
  Rename also the "Developer mode" to the "Development mode".
* bpo-32101: Add PYTHONDEVMODE environment variable
  Mention it in the development chapiter.
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Victor Stinner 2017-11-30 11:40:24 +01:00 committed by GitHub
parent 706e10b186
commit 5e3806f8cf
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10 changed files with 78 additions and 16 deletions

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@ -24,3 +24,6 @@ The list of modules described in this chapter is:
unittest.mock-examples.rst
2to3.rst
test.rst
See also the Python development mode: the :option:`-X` ``dev`` option and
:envvar:`PYTHONDEVMODE` environment variable.

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@ -334,6 +334,7 @@ always available.
:const:`bytes_warning` :option:`-b`
:const:`quiet` :option:`-q`
:const:`hash_randomization` :option:`-R`
:const:`dev_mode` :option:`-X` ``dev``
============================= =============================
.. versionchanged:: 3.2
@ -345,6 +346,9 @@ always available.
.. versionchanged:: 3.3
Removed obsolete ``division_warning`` attribute.
.. versionchanged:: 3.7
Added ``dev_mode`` attribute for the new :option:`-X` ``dev`` flag.
.. data:: float_info

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@ -411,7 +411,7 @@ Miscellaneous options
nested imports). Note that its output may be broken in multi-threaded
application. Typical usage is ``python3 -X importtime -c 'import
asyncio'``. See also :envvar:`PYTHONPROFILEIMPORTTIME`.
* ``-X dev``: enable CPython's "developer mode", introducing additional
* ``-X dev``: enable CPython's "development mode", introducing additional
runtime checks which are too expensive to be enabled by default. It should
not be more verbose than the default if the code is correct: new warnings
are only emitted when an issue is detected. Effect of the developer mode:
@ -426,6 +426,8 @@ Miscellaneous options
* Enable the :mod:`faulthandler` module to dump the Python traceback
on a crash.
* Enable :ref:`asyncio debug mode <asyncio-debug-mode>`.
* Set the :attr:`~sys.flags.dev_mode` attribute of :attr:`sys.flags` to
``True``
It also allows passing arbitrary values and retrieving them through the
:data:`sys._xoptions` dictionary.
@ -796,6 +798,14 @@ conflict.
.. versionadded:: 3.7
See :pep:`538` for more details.
.. envvar:: PYTHONDEVMODE
If this environment variable is set to a non-empty string, enable the
CPython "development mode". See the :option:`-X` ``dev`` option.
.. versionadded:: 3.7
Debug-mode variables
~~~~~~~~~~~~~~~~~~~~

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@ -185,10 +185,10 @@ resolution on Linux and Windows.
PEP written and implemented by Victor Stinner
New Developer Mode: -X dev
--------------------------
New Development Mode: -X dev
----------------------------
Add a new "developer mode": ``-X dev`` command line option to enable debug
Add a new "development mode": ``-X dev`` command line option to enable debug
checks at runtime.
In short, ``python3 -X dev ...`` behaves as ``PYTHONMALLOC=debug python3 -W
@ -371,6 +371,11 @@ string
expression pattern for braced placeholders and non-braced placeholders
separately. (Contributed by Barry Warsaw in :issue:`1198569`.)
sys
---
Added :attr:`sys.flags.dev_mode` flag for the new development mode.
time
----

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@ -27,11 +27,9 @@ def _is_debug_mode():
# before you define your coroutines. A downside of using this feature
# is that tracebacks show entries for the CoroWrapper.__next__ method
# when _DEBUG is true.
debug = (not sys.flags.ignore_environment and
bool(os.environ.get('PYTHONASYNCIODEBUG')))
if hasattr(sys, '_xoptions') and 'dev' in sys._xoptions:
debug = True
return debug
return (sys.flags.dev_mode
or (not sys.flags.ignore_environment
and bool(os.environ.get('PYTHONASYNCIODEBUG'))))
_DEBUG = _is_debug_mode()

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@ -508,14 +508,18 @@ class CmdLineTest(unittest.TestCase):
with self.subTest(envar_value=value):
assert_python_ok('-c', code, **env_vars)
def run_xdev(self, *args, check_exitcode=True):
def run_xdev(self, *args, check_exitcode=True, xdev=True):
env = dict(os.environ)
env.pop('PYTHONWARNINGS', None)
env.pop('PYTHONDEVMODE', None)
# Force malloc() to disable the debug hooks which are enabled
# by default for Python compiled in debug mode
env['PYTHONMALLOC'] = 'malloc'
args = (sys.executable, '-X', 'dev', *args)
if xdev:
args = (sys.executable, '-X', 'dev', *args)
else:
args = (sys.executable, *args)
proc = subprocess.run(args,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
@ -526,6 +530,14 @@ class CmdLineTest(unittest.TestCase):
return proc.stdout.rstrip()
def test_xdev(self):
# sys.flags.dev_mode
code = "import sys; print(sys.flags.dev_mode)"
out = self.run_xdev("-c", code, xdev=False)
self.assertEqual(out, "False")
out = self.run_xdev("-c", code)
self.assertEqual(out, "True")
# Warnings
code = ("import sys, warnings; "
"print(' '.join('%s::%s' % (f[0], f[2].__name__) "
"for f in warnings.filters))")
@ -555,6 +567,7 @@ class CmdLineTest(unittest.TestCase):
"default::ResourceWarning "
"default::Warning")
# Memory allocator debug hooks
try:
import _testcapi
except ImportError:
@ -569,6 +582,7 @@ class CmdLineTest(unittest.TestCase):
alloc_name = "malloc_debug"
self.assertEqual(out, alloc_name)
# Faulthandler
try:
import faulthandler
except ImportError:
@ -581,6 +595,7 @@ class CmdLineTest(unittest.TestCase):
def check_pythonmalloc(self, env_var, name):
code = 'import _testcapi; print(_testcapi.pymem_getallocatorsname())'
env = dict(os.environ)
env.pop('PYTHONDEVMODE', None)
if env_var is not None:
env['PYTHONMALLOC'] = env_var
else:
@ -621,6 +636,24 @@ class CmdLineTest(unittest.TestCase):
with self.subTest(env_var=env_var, name=name):
self.check_pythonmalloc(env_var, name)
def test_pythondevmode_env(self):
# Test the PYTHONDEVMODE environment variable
code = "import sys; print(sys.flags.dev_mode)"
env = dict(os.environ)
env.pop('PYTHONDEVMODE', None)
args = (sys.executable, '-c', code)
proc = subprocess.run(args, stdout=subprocess.PIPE,
universal_newlines=True, env=env)
self.assertEqual(proc.stdout.rstrip(), 'False')
self.assertEqual(proc.returncode, 0, proc)
env['PYTHONDEVMODE'] = '1'
proc = subprocess.run(args, stdout=subprocess.PIPE,
universal_newlines=True, env=env)
self.assertEqual(proc.stdout.rstrip(), 'True')
self.assertEqual(proc.returncode, 0, proc)
class IgnoreEnvironmentTest(unittest.TestCase):

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@ -526,10 +526,12 @@ class SysModuleTest(unittest.TestCase):
attrs = ("debug",
"inspect", "interactive", "optimize", "dont_write_bytecode",
"no_user_site", "no_site", "ignore_environment", "verbose",
"bytes_warning", "quiet", "hash_randomization", "isolated")
"bytes_warning", "quiet", "hash_randomization", "isolated",
"dev_mode")
for attr in attrs:
self.assertTrue(hasattr(sys.flags, attr), attr)
self.assertEqual(type(getattr(sys.flags, attr)), int, attr)
attr_type = bool if attr == "dev_mode" else int
self.assertEqual(type(getattr(sys.flags, attr)), attr_type, attr)
self.assertTrue(repr(sys.flags))
self.assertEqual(len(sys.flags), len(attrs))

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@ -0,0 +1 @@
Add :attr:`sys.flags.dev_mode` flag

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@ -124,7 +124,8 @@ static const char usage_6[] =
" hooks.\n"
"PYTHONCOERCECLOCALE: if this variable is set to 0, it disables the locale\n"
" coercion behavior. Use PYTHONCOERCECLOCALE=warn to request display of\n"
" locale coercion and locale compatibility warnings on stderr.\n";
" locale coercion and locale compatibility warnings on stderr.\n"
"PYTHONDEVMODE: enable the development mode.\n";
static void
pymain_usage(int error, const wchar_t* program)
@ -1520,7 +1521,9 @@ pymain_parse_envvars(_PyMain *pymain)
if (pymain_init_tracemalloc(pymain) < 0) {
return -1;
}
if (pymain_get_xoption(pymain, L"dev")) {
if (pymain_get_xoption(pymain, L"dev" ) ||
pymain_get_env_var("PYTHONDEVMODE"))
{
core_config->dev_mode = 1;
core_config->faulthandler = 1;
core_config->allocator = "debug";

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@ -1814,6 +1814,7 @@ static PyStructSequence_Field flags_fields[] = {
{"quiet", "-q"},
{"hash_randomization", "-R"},
{"isolated", "-I"},
{"dev_mode", "-X dev"},
{0}
};
@ -1821,7 +1822,7 @@ static PyStructSequence_Desc flags_desc = {
"sys.flags", /* name */
flags__doc__, /* doc */
flags_fields, /* fields */
13
14
};
static PyObject*
@ -1829,6 +1830,7 @@ make_flags(void)
{
int pos = 0;
PyObject *seq;
_PyCoreConfig *core_config = &_PyGILState_GetInterpreterStateUnsafe()->core_config;
seq = PyStructSequence_New(&FlagsType);
if (seq == NULL)
@ -1853,6 +1855,7 @@ make_flags(void)
SetFlag(Py_HashRandomizationFlag);
SetFlag(Py_IsolatedFlag);
#undef SetFlag
PyStructSequence_SET_ITEM(seq, pos++, PyBool_FromLong(core_config->dev_mode));
if (PyErr_Occurred()) {
Py_DECREF(seq);