Clarified some discrepancies in the platform module.

python · ned-deily · Mar 28, 2024 · Mar 16, 2024 · Mar 16, 2024 · Mar 19, 2024
commit 24b36625023c541b7d31a7211a43bc28d0ad72b5
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
@@ -784,6 +784,11 @@ process and user.
    :func:`socket.gethostname`  or even
    ``socket.gethostbyaddr(socket.gethostname())``.
 
+   On macOS, iOS and Android, this returns the *kernel* name and version (i.e.,
+   ``'Darwin'`` on macOS and iOS; ``'Linux'`` on Android), not the user-facing
+   operating system name. :func:`platform.uname()` can be used to get the
+   user-facing operating system name on iOS and Android.
+
    .. availability:: Unix.
 
    .. versionchanged:: 3.3

diff --git a/Doc/library/platform.rst b/Doc/library/platform.rst
@@ -148,6 +148,8 @@ Cross Platform
    Returns the system/OS name, such as ``'Linux'``, ``'Darwin'``, ``'Java'``,
    ``'Windows'``. An empty string is returned if the value cannot be determined.
 
+   On iOS, this returns the OS name (i.e, ``'iOS``` or ``'iPadOS'``), rather than
+   the kernel name (``'Darwin'``).
 
 .. function:: system_alias(system, release, version)
 
@@ -161,6 +163,8 @@ Cross Platform
    Returns the system's release version, e.g. ``'#3 on degas'``. An empty string is
    returned if the value cannot be determined.
 
+   On iOS, this is the iOS version, not the Darwin kernel version. To obtain
+   the Darwin kernel version, use :func:`os.uname()`.
 
 .. function:: uname()
 

@@ -3,24 +3,23 @@
     from ctypes import cdll, c_void_p, c_char_p, util
 except ImportError:
     # ctypes is an optional module. If it's not present, we're limited in what
-    # we can tell about the system, but we don't want to prevent the platform
-    # module from working.
+    # we can tell about the system, but we don't want to prevent the module
+    # from working.
+    print("ctypes isn't available; iOS system calls will not be available")
     objc = None
 else:
     # ctypes is available. Load the ObjC library, and wrap the objc_getClass,
-    # sel_registerName and objc_msgSend methods
-    objc = cdll.LoadLibrary(util.find_library("objc"))
-    if objc._name:
-        objc.objc_getClass.restype = c_void_p
-        objc.objc_getClass.argtypes = [c_char_p]
-        objc.sel_registerName.restype = c_void_p
-        objc.sel_registerName.argtypes = [c_char_p]
-        # The calls to objc_msgSend all have no arguments; but the return types
-        # vary with the specific call.
-        objc.objc_msgSend.argtypes = [c_void_p, c_void_p]
-    else:
+    # sel_registerName methods
+    lib = util.find_library("objc")
+    if lib is None:
         # Failed to load the objc library
-        objc = None
+        raise RuntimeError("ObjC runtime library couldn't be loaded")
+
+    objc = cdll.LoadLibrary(lib)
+    objc.objc_getClass.restype = c_void_p
+    objc.objc_getClass.argtypes = [c_char_p]
+    objc.sel_registerName.restype = c_void_p
+    objc.sel_registerName.argtypes = [c_char_p]
 
 
 def get_platform_ios():
@@ -33,6 +32,8 @@ def get_platform_ios():
 
     # Most of the methods return ObjC objects
     objc.objc_msgSend.restype = c_void_p
+    # All the methods used have no arguments.
+    objc.objc_msgSend.argtypes = [c_void_p, c_void_p]
 
     # Equivalent of:
     #   device = [UIDevice currentDevice]

diff --git a/Lib/platform.py b/Lib/platform.py
@@ -842,8 +842,9 @@ def get_OpenVMS():
             csid, cpu_number = vms_lib.getsyi('SYI$_CPU', 0)
             return 'Alpha' if cpu_number >= 128 else 'VAX'
 
-    # On iOS, os.uname returns the architecture as uname.machine. On device it
-    # doesn't; but there's only one CPU architecture on device.
+    # On the iOS simulator, os.uname returns the architecture as uname.machine.
+    # On device it returns the model name for some reason; but there's only one
+    # CPU architecture for iOS devices, so we know the right answer.
     def get_ios():
         if sys.implementation._multiarch.endswith("simulator"):
             return os.uname().machine
@@ -1005,7 +1006,7 @@ def uname():
 
     # Normalize responses on iOS
     if sys.platform == 'ios':
-        system, release, machine, _ = ios_ver()
+        system, release, _, _ = ios_ver()
 
     vals = system, node, release, version, machine
     # Replace 'unknown' values with the more portable ''

diff --git a/Lib/test/test_platform.py b/Lib/test/test_platform.py
@@ -219,6 +219,10 @@ def test_uname(self):
         self.assertEqual(res[-1], res.processor)
         self.assertEqual(len(res), 6)
 
+        if sys.platform == "ios":
+            self.assertIn(res.system, {"iOS", "iPadOS"})
+            self.assertIn(res.release, platform.ios_ver().release)
+
     @unittest.skipUnless(sys.platform.startswith('win'), "windows only test")
     def test_uname_win32_without_wmi(self):
         def raises_oserror(*a):
@@ -451,6 +455,13 @@ def test_ios_ver(self):
             self.assertEqual(result.model, "")
             self.assertFalse(result.is_simulator)
 
+            # Check the fallback values can be overridden by arguments
+            override = platform.ios_ver("Foo", "Bar", "Whiz", True)
+            self.assertEqual(override.system, "Foo")
+            self.assertEqual(override.release, "Bar")
+            self.assertEqual(override.model, "Whiz")
+            self.assertTrue(override.is_simulator)
+
     @unittest.skipIf(support.is_emscripten, "Does not apply to Emscripten")
     def test_libc_ver(self):
         # check that libc_ver(executable) doesn't raise an exception