gh-152433: Windows: modernize and refactor stat emulation APIs (GH-153700)

This allows build on more API sets (e.g. UWP) without excluding any currently supported desktop OS.

Author: thexai

Misc/NEWS.d/next/Windows/2026-07-17-16-21-17.gh-issue-152433.45rR2A.rst

@@ -0,0 +1,2 @@
+Modernize fileutils removing GetFileInformationByHandle API calls and allow
+build for Universal Windows Platform.

Modules/posixmodule.c

@@ -829,9 +829,9 @@ PyOS_AfterFork(void)
 #ifdef MS_WINDOWS
 /* defined in fileutils.c */
 void _Py_time_t_to_FILE_TIME(time_t, int, FILETIME *);
-void _Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *, ULONG,
-                                FILE_BASIC_INFO *, FILE_ID_INFO *,
-                                struct _Py_stat_struct *);
+void _Py_attribute_data_to_stat(FILE_STANDARD_INFO*, ULONG,
+                                FILE_BASIC_INFO*, FILE_ID_INFO*,
+                                struct _Py_stat_struct*);
 void _Py_stat_basic_info_to_stat(FILE_STAT_BASIC_INFORMATION *,
                                  struct _Py_stat_struct *);
 #endif
@@ -2025,25 +2025,31 @@ win32_wchdir(LPCWSTR path)
 
 static void
 find_data_to_file_info(WIN32_FIND_DATAW *pFileData,
-                       BY_HANDLE_FILE_INFORMATION *info,
+                       FILE_BASIC_INFO* basic_info,
+                       FILE_STANDARD_INFO* standard_info,
                        ULONG *reparse_tag)
 {
-    memset(info, 0, sizeof(*info));
-    info->dwFileAttributes = pFileData->dwFileAttributes;
-    info->ftCreationTime   = pFileData->ftCreationTime;
-    info->ftLastAccessTime = pFileData->ftLastAccessTime;
-    info->ftLastWriteTime  = pFileData->ftLastWriteTime;
-    info->nFileSizeHigh    = pFileData->nFileSizeHigh;
-    info->nFileSizeLow     = pFileData->nFileSizeLow;
-/*  info->nNumberOfLinks   = 1; */
+    memset(basic_info, 0, sizeof(*basic_info));
+    memset(standard_info, 0, sizeof(*standard_info));
+
+    basic_info->FileAttributes = pFileData->dwFileAttributes;
+    basic_info->CreationTime.HighPart = pFileData->ftCreationTime.dwHighDateTime;
+    basic_info->CreationTime.LowPart = pFileData->ftCreationTime.dwLowDateTime;
+    basic_info->LastAccessTime.HighPart = pFileData->ftLastAccessTime.dwHighDateTime;
+    basic_info->LastAccessTime.LowPart = pFileData->ftLastAccessTime.dwLowDateTime;
+    basic_info->LastWriteTime.HighPart = pFileData->ftLastWriteTime.dwHighDateTime;
+    basic_info->LastWriteTime.LowPart = pFileData->ftLastWriteTime.dwLowDateTime;
+    standard_info->EndOfFile.HighPart = pFileData->nFileSizeHigh;
+    standard_info->EndOfFile.LowPart = pFileData->nFileSizeLow;
+
     if (pFileData->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
         *reparse_tag = pFileData->dwReserved0;
     else
         *reparse_tag = 0;
 }
 
 static BOOL
-attributes_from_dir(LPCWSTR pszFile, BY_HANDLE_FILE_INFORMATION *info, ULONG *reparse_tag)
+attributes_from_dir(LPCWSTR pszFile, FILE_BASIC_INFO* basic_info, FILE_STANDARD_INFO* standard_info, ULONG* reparse_tag)
 {
     HANDLE hFindFile;
     WIN32_FIND_DATAW FileData;
@@ -2074,7 +2080,7 @@ attributes_from_dir(LPCWSTR pszFile, BY_HANDLE_FILE_INFORMATION *info, ULONG *re
         return FALSE;
     }
     FindClose(hFindFile);
-    find_data_to_file_info(&FileData, info, reparse_tag);
+    find_data_to_file_info(&FileData, basic_info, standard_info, reparse_tag);
     return TRUE;
 }
 
@@ -2108,10 +2114,9 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
                       BOOL traverse)
 {
     HANDLE hFile;
-    BY_HANDLE_FILE_INFORMATION fileInfo;
-    FILE_BASIC_INFO basicInfo;
-    FILE_BASIC_INFO *pBasicInfo = NULL;
-    FILE_ID_INFO idInfo;
+    FILE_STANDARD_INFO standardInfo = {0};
+    FILE_BASIC_INFO basicInfo = {0};
+    FILE_ID_INFO idInfo = {0};
     FILE_ID_INFO *pIdInfo = NULL;
     FILE_ATTRIBUTE_TAG_INFO tagInfo = { 0 };
     DWORD fileType, error;
@@ -2132,7 +2137,7 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
         case ERROR_ACCESS_DENIED:     /* Cannot sync or read attributes. */
         case ERROR_SHARING_VIOLATION: /* It's a paging file. */
             /* Try reading the parent directory. */
-            if (!attributes_from_dir(path, &fileInfo, &tagInfo.ReparseTag)) {
+            if (!attributes_from_dir(path, &basicInfo, &standardInfo, &tagInfo.ReparseTag)) {
                 /* Cannot read the parent directory. */
                 switch (GetLastError()) {
                 case ERROR_FILE_NOT_FOUND: /* File cannot be found */
@@ -2147,7 +2152,7 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
 
                 return -1;
             }
-            if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+            if (basicInfo.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                 if (traverse ||
                     !IsReparseTagNameSurrogate(tagInfo.ReparseTag)) {
                     /* The stat call has to traverse but cannot, so fail. */
@@ -2247,9 +2252,8 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
             }
         }
 
-        if (!GetFileInformationByHandle(hFile, &fileInfo) ||
-            !GetFileInformationByHandleEx(hFile, FileBasicInfo,
-                                          &basicInfo, sizeof(basicInfo))) {
+        if (!GetFileInformationByHandleEx(hFile, FileStandardInfo, &standardInfo, sizeof(standardInfo)) ||
+            !GetFileInformationByHandleEx(hFile, FileBasicInfo, &basicInfo, sizeof(basicInfo))) {
             switch (GetLastError()) {
             case ERROR_INVALID_PARAMETER:
             case ERROR_INVALID_FUNCTION:
@@ -2264,17 +2268,14 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
             goto cleanup;
         }
 
-        /* Successfully got FileBasicInfo, so we'll pass it along */
-        pBasicInfo = &basicInfo;
-
         if (GetFileInformationByHandleEx(hFile, FileIdInfo, &idInfo, sizeof(idInfo))) {
             /* Successfully got FileIdInfo, so pass it along */
             pIdInfo = &idInfo;
         }
     }
 
-    _Py_attribute_data_to_stat(&fileInfo, tagInfo.ReparseTag, pBasicInfo, pIdInfo, result);
-    update_st_mode_from_path(path, fileInfo.dwFileAttributes, result);
+    _Py_attribute_data_to_stat(&standardInfo, tagInfo.ReparseTag, &basicInfo, pIdInfo, result);
+    update_st_mode_from_path(path, basicInfo.FileAttributes, result);
 
 cleanup:
     if (hFile != INVALID_HANDLE_VALUE) {
@@ -16702,7 +16703,8 @@ static PyObject *
 DirEntry_from_find_data(PyObject *module, path_t *path, WIN32_FIND_DATAW *dataW)
 {
     DirEntry *entry;
-    BY_HANDLE_FILE_INFORMATION file_info;
+    FILE_BASIC_INFO basic_info;
+    FILE_STANDARD_INFO standard_info;
     ULONG reparse_tag;
     wchar_t *joined_path;
 
@@ -16740,8 +16742,8 @@ DirEntry_from_find_data(PyObject *module, path_t *path, WIN32_FIND_DATAW *dataW)
             goto error;
     }
 
-    find_data_to_file_info(dataW, &file_info, &reparse_tag);
-    _Py_attribute_data_to_stat(&file_info, reparse_tag, NULL, NULL, &entry->win32_lstat);
+    find_data_to_file_info(dataW, &basic_info, &standard_info, &reparse_tag);
+    _Py_attribute_data_to_stat(&standard_info, reparse_tag, &basic_info, NULL, &entry->win32_lstat);
 
     /* ctime is only deprecated from 3.12, so we copy birthtime across */
     entry->win32_lstat.st_ctime = entry->win32_lstat.st_birthtime;

Python/fileutils.c

@@ -1103,50 +1103,41 @@ typedef union {
 
 
 void
-_Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,
+_Py_attribute_data_to_stat(FILE_STANDARD_INFO* standard_info, ULONG reparse_tag,
                            FILE_BASIC_INFO *basic_info, FILE_ID_INFO *id_info,
                            struct _Py_stat_struct *result)
 {
     memset(result, 0, sizeof(*result));
-    result->st_mode = attributes_to_mode(info->dwFileAttributes);
-    result->st_size = (((__int64)info->nFileSizeHigh)<<32) + info->nFileSizeLow;
-    result->st_dev = id_info ? id_info->VolumeSerialNumber : info->dwVolumeSerialNumber;
-    result->st_rdev = 0;
+
+    result->st_size = standard_info->EndOfFile.QuadPart;
+    result->st_nlink = standard_info->NumberOfLinks;
+
     /* st_ctime is deprecated, but we preserve the legacy value in our caller, not here */
-    if (basic_info) {
-        LARGE_INTEGER_to_time_t_nsec(&basic_info->CreationTime, &result->st_birthtime, &result->st_birthtime_nsec);
-        LARGE_INTEGER_to_time_t_nsec(&basic_info->ChangeTime, &result->st_ctime, &result->st_ctime_nsec);
-        LARGE_INTEGER_to_time_t_nsec(&basic_info->LastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
-        LARGE_INTEGER_to_time_t_nsec(&basic_info->LastAccessTime, &result->st_atime, &result->st_atime_nsec);
-    } else {
-        FILE_TIME_to_time_t_nsec(&info->ftCreationTime, &result->st_birthtime, &result->st_birthtime_nsec);
-        FILE_TIME_to_time_t_nsec(&info->ftLastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
-        FILE_TIME_to_time_t_nsec(&info->ftLastAccessTime, &result->st_atime, &result->st_atime_nsec);
-    }
-    result->st_nlink = info->nNumberOfLinks;
+    LARGE_INTEGER_to_time_t_nsec(&basic_info->CreationTime, &result->st_birthtime, &result->st_birthtime_nsec);
+    LARGE_INTEGER_to_time_t_nsec(&basic_info->ChangeTime, &result->st_ctime, &result->st_ctime_nsec);
+    LARGE_INTEGER_to_time_t_nsec(&basic_info->LastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
+    LARGE_INTEGER_to_time_t_nsec(&basic_info->LastAccessTime, &result->st_atime, &result->st_atime_nsec);
 
     if (id_info) {
+        result->st_dev = id_info->VolumeSerialNumber;
         id_128_to_ino file_id;
         file_id.id = id_info->FileId;
         result->st_ino = file_id.st_ino;
         result->st_ino_high = file_id.st_ino_high;
     }
-    if (!result->st_ino && !result->st_ino_high) {
-        /* should only occur for DirEntry_from_find_data, in which case the
-           index is likely to be zero anyway. */
-        result->st_ino = (((uint64_t)info->nFileIndexHigh) << 32) + info->nFileIndexLow;
-    }
+
+    result->st_file_attributes = basic_info->FileAttributes;
+    result->st_mode = attributes_to_mode(result->st_file_attributes);
 
     /* bpo-37834: Only actual symlinks set the S_IFLNK flag. But lstat() will
        open other name surrogate reparse points without traversing them. To
        detect/handle these, check st_file_attributes and st_reparse_tag. */
     result->st_reparse_tag = reparse_tag;
-    if (info->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
+    if (result->st_file_attributes & FILE_ATTRIBUTE_REPARSE_POINT &&
         reparse_tag == IO_REPARSE_TAG_SYMLINK) {
         /* set the bits that make this a symlink */
         result->st_mode = (result->st_mode & ~S_IFMT) | S_IFLNK;
     }
-    result->st_file_attributes = info->dwFileAttributes;
 }
 
 void
@@ -1231,9 +1222,9 @@ int
 _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
 {
 #ifdef MS_WINDOWS
-    BY_HANDLE_FILE_INFORMATION info;
-    FILE_BASIC_INFO basicInfo;
-    FILE_ID_INFO idInfo;
+    FILE_STANDARD_INFO standardInfo = {0};
+    FILE_BASIC_INFO basicInfo = {0};
+    FILE_ID_INFO idInfo = {0};
     FILE_ID_INFO *pIdInfo = &idInfo;
     HANDLE h;
     int type;
@@ -1266,7 +1257,7 @@ _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
         return 0;
     }
 
-    if (!GetFileInformationByHandle(h, &info) ||
+    if (!GetFileInformationByHandleEx(h,FileStandardInfo, &standardInfo, sizeof(standardInfo)) ||
         !GetFileInformationByHandleEx(h, FileBasicInfo, &basicInfo, sizeof(basicInfo))) {
         /* The Win32 error is already set, but we also set errno for
            callers who expect it */
@@ -1279,7 +1270,7 @@ _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
         pIdInfo = NULL;
     }
 
-    _Py_attribute_data_to_stat(&info, 0, &basicInfo, pIdInfo, status);
+    _Py_attribute_data_to_stat(&standardInfo, 0, &basicInfo, pIdInfo, status);
     return 0;
 #else
     return fstat(fd, status);