gh-152433: Windows: allow posixmodule.c to build for Windows UWP

Author: thexai

Misc/NEWS.d/next/Windows/2026-07-04-08-18-04.gh-issue-152433.iub_pL.rst

@@ -0,0 +1 @@
+Allow ``posixmodule.c`` to build for Windows UWP.

Modules/clinic/posixmodule.c.h

@@ -5197,7 +5197,7 @@ os_listdrives_impl(PyObject *module)
 
 #endif /* MS_WINDOWS_DESKTOP || MS_WINDOWS_SYSTEM */
 
-#if defined(MS_WINDOWS_APP) || defined(MS_WINDOWS_SYSTEM)
+#if defined(MS_MS_WINDOWS_DESKTOP) || defined(MS_WINDOWS_SYSTEM)
 
 /*[clinic input]
 os.listvolumes
@@ -5260,7 +5260,7 @@ os_listvolumes_impl(PyObject *module)
     return result;
 }
 
-#endif /* MS_WINDOWS_APP || MS_WINDOWS_SYSTEM */
+#endif /* MS_WINDOWS_DESKTOP || MS_WINDOWS_SYSTEM */
 
 #if defined(MS_WINDOWS_DESKTOP) || defined(MS_WINDOWS_SYSTEM)
 
@@ -9933,6 +9933,7 @@ os_setpgrp_impl(PyObject *module)
 #include <winternl.h>
 #include <ProcessSnapshot.h>
 
+#ifdef MS_WINDOWS_DESKTOP
 // The structure definition in winternl.h may be incomplete.
 // This structure is the full version from the MSDN documentation.
 typedef struct _PROCESS_BASIC_INFORMATION_FULL {
@@ -10005,6 +10006,7 @@ win32_getppid_fast(void)
     cached_ppid = (ULONG) basic_information.InheritedFromUniqueProcessId;
     return cached_ppid;
 }
+#endif // MS_WINDOWS_DESKTOP
 
 static PyObject*
 win32_getppid(void)
@@ -10013,12 +10015,13 @@ win32_getppid(void)
     PyObject* result = NULL;
     HANDLE process = GetCurrentProcess();
     HPSS snapshot = NULL;
-    ULONG pid;
 
-    pid = win32_getppid_fast();
+#ifdef MS_WINDOWS_DESKTOP
+    ULONG pid = win32_getppid_fast();
     if (pid != 0) {
         return PyLong_FromUnsignedLong(pid);
     }
+#endif
 
     // If failure occurs in win32_getppid_fast(), fall back to using the PSS API.
 
@@ -15227,6 +15230,7 @@ os_abort_impl(PyObject *module)
 }
 
 #ifdef MS_WINDOWS
+#ifdef MS_WINDOWS_DESKTOP
 /* Grab ShellExecute dynamically from shell32 */
 static int has_ShellExecute = -1;
 static HINSTANCE (CALLBACK *Py_ShellExecuteW)(HWND, LPCWSTR, LPCWSTR, LPCWSTR,
@@ -15255,6 +15259,7 @@ check_ShellExecute(void)
     }
     return has_ShellExecute;
 }
+#endif // MS_WINDOWS_DESKTOP
 
 
 /*[clinic input]
@@ -15299,6 +15304,9 @@ os_startfile_impl(PyObject *module, path_t *filepath,
                   path_t *cwd, int show_cmd)
 /*[clinic end generated code: output=1c6f2f3340e31ffa input=8248997b80669622]*/
 {
+#if defined(MS_WINDOWS_APP) && !defined(MS_WINDOWS_DESKTOP)
+    return PyErr_Format(PyExc_NotImplementedError, "startfile not available on UWP");
+#else
     HINSTANCE rc;
 
     if(!check_ShellExecute()) {
@@ -15327,6 +15335,7 @@ os_startfile_impl(PyObject *module, path_t *filepath,
         return NULL;
     }
     Py_RETURN_NONE;
+#endif
 }
 #endif /* MS_WINDOWS */