bpo-31845: Fix reading flags from environment (GH-4105)
The startup refactoring means command line settings
are now applied after settings are read from the
environment.
This updates the way command line settings are applied
to account for that, ensures more settings are first read
from the environment in _PyInitializeCore, and adds a
simple test case covering the flags that are easy to check.
diff --git a/Lib/test/test_cmd_line.py b/Lib/test/test_cmd_line.py
index 28ddb2b..1b584eb 100644
--- a/Lib/test/test_cmd_line.py
+++ b/Lib/test/test_cmd_line.py
@@ -12,7 +12,6 @@
spawn_python, kill_python, assert_python_ok, assert_python_failure
)
-
# XXX (ncoghlan): Move to script_helper and make consistent with run_python
def _kill_python_and_exit_code(p):
data = kill_python(p)
@@ -486,6 +485,26 @@
cwd=tmpdir)
self.assertEqual(out.strip(), b"ok")
+ def test_sys_flags_set(self):
+ # Issue 31845: a startup refactoring broke reading flags from env vars
+ for value, expected in (("", 0), ("1", 1), ("text", 1), ("2", 2)):
+ env_vars = dict(
+ PYTHONDEBUG=value,
+ PYTHONOPTIMIZE=value,
+ PYTHONDONTWRITEBYTECODE=value,
+ PYTHONVERBOSE=value,
+ )
+ code = (
+ "import sys; "
+ "sys.stderr.write(str(sys.flags)); "
+ f"""sys.exit(not (
+ sys.flags.debug == sys.flags.optimize ==
+ sys.flags.dont_write_bytecode == sys.flags.verbose ==
+ {expected}
+ ))"""
+ )
+ with self.subTest(envar_value=value):
+ assert_python_ok('-c', code, **env_vars)
class IgnoreEnvironmentTest(unittest.TestCase):
@@ -506,6 +525,20 @@
self.run_ignoring_vars("sys.flags.hash_randomization == 1",
PYTHONHASHSEED="0")
+ def test_sys_flags_not_set(self):
+ # Issue 31845: a startup refactoring broke reading flags from env vars
+ expected_outcome = """
+ (sys.flags.debug == sys.flags.optimize ==
+ sys.flags.dont_write_bytecode == sys.flags.verbose == 0)
+ """
+ self.run_ignoring_vars(
+ expected_outcome,
+ PYTHONDEBUG="1",
+ PYTHONOPTIMIZE="1",
+ PYTHONDONTWRITEBYTECODE="1",
+ PYTHONVERBOSE="1",
+ )
+
def test_main():
test.support.run_unittest(CmdLineTest, IgnoreEnvironmentTest)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-10-24-21-27-32.bpo-31845.8OS-k3.rst b/Misc/NEWS.d/next/Core and Builtins/2017-10-24-21-27-32.bpo-31845.8OS-k3.rst
new file mode 100644
index 0000000..ddaf630
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2017-10-24-21-27-32.bpo-31845.8OS-k3.rst
@@ -0,0 +1 @@
+Environment variables are once more read correctly at interpreter startup.
diff --git a/Modules/main.c b/Modules/main.c
index e862113..846ecb6 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -522,39 +522,33 @@
return 0;
}
+static void
+maybe_set_flag(int *flag, int value)
+{
+ /* Helper to set flag variables from command line options
+ * - uses the higher of the two values if they're both set
+ * - otherwise leaves the flag unset
+ */
+ if (*flag < value) {
+ *flag = value;
+ }
+}
+
static int
apply_command_line_and_environment(_Py_CommandLineDetails *cmdline)
{
- char *p;
- Py_BytesWarningFlag = cmdline->bytes_warning;
- Py_DebugFlag = cmdline->debug;
- Py_InspectFlag = cmdline->inspect;
- Py_InteractiveFlag = cmdline->interactive;
- Py_IsolatedFlag = cmdline->isolated;
- Py_OptimizeFlag = cmdline->optimization_level;
- Py_DontWriteBytecodeFlag = cmdline->dont_write_bytecode;
- Py_NoUserSiteDirectory = cmdline->no_user_site_directory;
- Py_NoSiteFlag = cmdline->no_site_import;
- Py_UnbufferedStdioFlag = cmdline->use_unbuffered_io;
- Py_VerboseFlag = cmdline->verbosity;
- Py_QuietFlag = cmdline->quiet_flag;
-
- if (!Py_InspectFlag &&
- (p = Py_GETENV("PYTHONINSPECT")) && *p != '\0') {
- Py_InspectFlag = 1;
- cmdline->inspect = 1;
- }
- if (!cmdline->use_unbuffered_io &&
- (p = Py_GETENV("PYTHONUNBUFFERED")) && *p != '\0') {
- Py_UnbufferedStdioFlag = 1;
- cmdline->use_unbuffered_io = 1;
- }
-
- if (!Py_NoUserSiteDirectory &&
- (p = Py_GETENV("PYTHONNOUSERSITE")) && *p != '\0') {
- Py_NoUserSiteDirectory = 1;
- cmdline->no_user_site_directory = 1;
- }
+ maybe_set_flag(&Py_BytesWarningFlag, cmdline->bytes_warning);
+ maybe_set_flag(&Py_DebugFlag, cmdline->debug);
+ maybe_set_flag(&Py_InspectFlag, cmdline->inspect);
+ maybe_set_flag(&Py_InteractiveFlag, cmdline->interactive);
+ maybe_set_flag(&Py_IsolatedFlag, cmdline->isolated);
+ maybe_set_flag(&Py_OptimizeFlag, cmdline->optimization_level);
+ maybe_set_flag(&Py_DontWriteBytecodeFlag, cmdline->dont_write_bytecode);
+ maybe_set_flag(&Py_NoUserSiteDirectory, cmdline->no_user_site_directory);
+ maybe_set_flag(&Py_NoSiteFlag, cmdline->no_site_import);
+ maybe_set_flag(&Py_UnbufferedStdioFlag, cmdline->use_unbuffered_io);
+ maybe_set_flag(&Py_VerboseFlag, cmdline->verbosity);
+ maybe_set_flag(&Py_QuietFlag, cmdline->quiet_flag);
/* TODO: Apply PYTHONWARNINGS & -W options to sys module here */
/* TODO: Apply -X options to sys module here */
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 5b13bc4..4e8bbb6 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -217,15 +217,18 @@
*/
-static int
-add_flag(int flag, const char *envs)
+static void
+set_flag(int *flag, const char *envs)
{
+ /* Helper to set flag variables from environment variables:
+ * - uses the higher of the two values if they're both set
+ * - otherwise sets the flag to 1
+ */
int env = atoi(envs);
- if (flag < env)
- flag = env;
- if (flag < 1)
- flag = 1;
- return flag;
+ if (*flag < env)
+ *flag = env;
+ if (*flag < 1)
+ *flag = 1;
}
static char*
@@ -612,22 +615,28 @@
#endif
if ((p = Py_GETENV("PYTHONDEBUG")) && *p != '\0')
- Py_DebugFlag = add_flag(Py_DebugFlag, p);
+ set_flag(&Py_DebugFlag, p);
if ((p = Py_GETENV("PYTHONVERBOSE")) && *p != '\0')
- Py_VerboseFlag = add_flag(Py_VerboseFlag, p);
+ set_flag(&Py_VerboseFlag, p);
if ((p = Py_GETENV("PYTHONOPTIMIZE")) && *p != '\0')
- Py_OptimizeFlag = add_flag(Py_OptimizeFlag, p);
+ set_flag(&Py_OptimizeFlag, p);
+ if ((p = Py_GETENV("PYTHONINSPECT")) && *p != '\0')
+ set_flag(&Py_InspectFlag, p);
if ((p = Py_GETENV("PYTHONDONTWRITEBYTECODE")) && *p != '\0')
- Py_DontWriteBytecodeFlag = add_flag(Py_DontWriteBytecodeFlag, p);
+ set_flag(&Py_DontWriteBytecodeFlag, p);
+ if ((p = Py_GETENV("PYTHONNOUSERSITE")) && *p != '\0')
+ set_flag(&Py_NoUserSiteDirectory, p);
+ if ((p = Py_GETENV("PYTHONUNBUFFERED")) && *p != '\0')
+ set_flag(&Py_UnbufferedStdioFlag, p);
/* The variable is only tested for existence here;
_Py_HashRandomization_Init will check its value further. */
if ((p = Py_GETENV("PYTHONHASHSEED")) && *p != '\0')
- Py_HashRandomizationFlag = add_flag(Py_HashRandomizationFlag, p);
+ set_flag(&Py_HashRandomizationFlag, p);
#ifdef MS_WINDOWS
if ((p = Py_GETENV("PYTHONLEGACYWINDOWSFSENCODING")) && *p != '\0')
- Py_LegacyWindowsFSEncodingFlag = add_flag(Py_LegacyWindowsFSEncodingFlag, p);
+ set_flag(&Py_LegacyWindowsFSEncodingFlag, p);
if ((p = Py_GETENV("PYTHONLEGACYWINDOWSSTDIO")) && *p != '\0')
- Py_LegacyWindowsStdioFlag = add_flag(Py_LegacyWindowsStdioFlag, p);
+ set_flag(&Py_LegacyWindowsStdioFlag, p);
#endif
_Py_HashRandomization_Init(&core_config);