bpo-44131: Py_FrozenMain() uses PyConfig_SetBytesArgv() (GH-26201)

Moreover, Py_FrozenMain() relies on Py_InitializeFromConfig() to
handle the PYTHONUNBUFFERED environment variable and configure C
stdio streams like stdout (make the stream unbuffered).

Author: vstinner

Lib/test/test_embed.py

@@ -1484,14 +1484,18 @@ def test_unicode_id_init(self):
     @unittest.skipIf(os.name == 'nt',
                      'Py_FrozenMain is not exported on Windows')
     def test_frozenmain(self):
-        out, err = self.run_embedded_interpreter("test_frozenmain")
-        exe = os.path.realpath('./argv0')
+        env = dict(os.environ)
+        env['PYTHONUNBUFFERED'] = '1'
+        out, err = self.run_embedded_interpreter("test_frozenmain", env=env)
+        executable = os.path.realpath('./argv0')
         expected = textwrap.dedent(f"""
             Frozen Hello World
             sys.argv ['./argv0', '-E', 'arg1', 'arg2']
             config program_name: ./argv0
-            config executable: {exe}
+            config executable: {executable}
             config use_environment: 1
+            config configure_c_stdio: 1
+            config buffered_stdio: 0
         """).lstrip()
         self.assertEqual(out, expected)
 

Programs/test_frozenmain.h

@@ -7,6 +7,11 @@
 print("Frozen Hello World")
 print("sys.argv", sys.argv)
 config = _testinternalcapi.get_configs()['config']
-print(f"config program_name: {config['program_name']}")
-print(f"config executable: {config['executable']}")
-print(f"config use_environment: {config['use_environment']}")
+for key in (
+    'program_name',
+    'executable',
+    'use_environment',
+    'configure_c_stdio',
+    'buffered_stdio',
+):
+    print(f"config {key}: {config[key]}")

Programs/test_frozenmain.py

@@ -20,74 +20,28 @@ Py_FrozenMain(int argc, char **argv)
         Py_ExitStatusException(status);
     }
 
-    const char *p;
-    int i, n, sts = 1;
-    int inspect = 0;
-    int unbuffered = 0;
-    char *oldloc = NULL;
-    wchar_t **argv_copy = NULL;
-    /* We need a second copies, as Python might modify the first one. */
-    wchar_t **argv_copy2 = NULL;
-
-    if (argc > 0) {
-        argv_copy = PyMem_RawMalloc(sizeof(wchar_t*) * argc);
-        argv_copy2 = PyMem_RawMalloc(sizeof(wchar_t*) * argc);
-        if (!argv_copy || !argv_copy2) {
-            fprintf(stderr, "out of memory\n");
-            goto error;
-        }
-    }
-
     PyConfig config;
     PyConfig_InitPythonConfig(&config);
-    config.pathconfig_warnings = 0;   /* Suppress errors from getpath.c */
-
-    if ((p = Py_GETENV("PYTHONINSPECT")) && *p != '\0') {
-        inspect = 1;
-    }
-    if ((p = Py_GETENV("PYTHONUNBUFFERED")) && *p != '\0') {
-        unbuffered = 1;
-    }
-
-    if (unbuffered) {
-        setbuf(stdin, (char *)NULL);
-        setbuf(stdout, (char *)NULL);
-        setbuf(stderr, (char *)NULL);
-    }
+    // Suppress errors from getpath.c
+    config.pathconfig_warnings = 0;
+    // Don't parse command line options like -E
+    config.parse_argv = 0;
 
-    oldloc = _PyMem_RawStrdup(setlocale(LC_ALL, NULL));
-    if (!oldloc) {
-        fprintf(stderr, "out of memory\n");
-        goto error;
+    status = PyConfig_SetBytesArgv(&config, argc, argv);
+    if (PyStatus_Exception(status)) {
+        PyConfig_Clear(&config);
+        Py_ExitStatusException(status);
     }
 
-    setlocale(LC_ALL, "");
-    for (i = 0; i < argc; i++) {
-        argv_copy[i] = Py_DecodeLocale(argv[i], NULL);
-        argv_copy2[i] = argv_copy[i];
-        if (!argv_copy[i]) {
-            fprintf(stderr,
-                    "Unable to decode the command line argument #%i\n",
-                    i + 1);
-            argc = i;
-            goto error;
-        }
+    const char *p;
+    int inspect = 0;
+    if ((p = Py_GETENV("PYTHONINSPECT")) && *p != '\0') {
+        inspect = 1;
     }
-    setlocale(LC_ALL, oldloc);
-    PyMem_RawFree(oldloc);
-    oldloc = NULL;
 
 #ifdef MS_WINDOWS
     PyInitFrozenExtensions();
 #endif /* MS_WINDOWS */
-    if (argc >= 1) {
-        status = PyConfig_SetString(&config, &config.program_name,
-                                    argv_copy[0]);
-        if (PyStatus_Exception(status)) {
-            PyConfig_Clear(&config);
-            Py_ExitStatusException(status);
-        }
-    }
 
     status = Py_InitializeFromConfig(&config);
     PyConfig_Clear(&config);
@@ -104,9 +58,8 @@ Py_FrozenMain(int argc, char **argv)
                 Py_GetVersion(), Py_GetCopyright());
     }
 
-    PySys_SetArgv(argc, argv_copy);
-
-    n = PyImport_ImportFrozenModule("__main__");
+    int sts = 1;
+    int n = PyImport_ImportFrozenModule("__main__");
     if (n == 0) {
         Py_FatalError("the __main__ module is not frozen");
     }
@@ -128,14 +81,5 @@ Py_FrozenMain(int argc, char **argv)
     if (Py_FinalizeEx() < 0) {
         sts = 120;
     }
-
-error:
-    PyMem_RawFree(argv_copy);
-    if (argv_copy2) {
-        for (i = 0; i < argc; i++)
-            PyMem_RawFree(argv_copy2[i]);
-        PyMem_RawFree(argv_copy2);
-    }
-    PyMem_RawFree(oldloc);
     return sts;
 }