gh-152433: Windows: modernize fileutils to allow build for Windows UWP

Author: thexai

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

@@ -0,0 +1 @@
+Modernize fileutils to allow build for Windows UWP.

Modules/posixmodule.c

@@ -834,6 +834,9 @@ void _Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *, ULONG,
                                 struct _Py_stat_struct *);
 void _Py_stat_basic_info_to_stat(FILE_STAT_BASIC_INFORMATION *,
                                  struct _Py_stat_struct *);
+void _Py_attribute_data_to_stat_UWP(FILE_STANDARD_INFO*, ULONG,
+                                    FILE_BASIC_INFO*, struct _Py_stat_struct*);
+void _Py_find_data_to_stat(WIN32_FIND_DATAW* find_data, struct _Py_stat_struct* result);
 #endif
 
 
@@ -2023,27 +2026,8 @@ win32_wchdir(LPCWSTR path)
 #define HAVE_STRUCT_STAT_ST_FILE_ATTRIBUTES 1
 #define HAVE_STRUCT_STAT_ST_REPARSE_TAG 1
 
-static void
-find_data_to_file_info(WIN32_FIND_DATAW *pFileData,
-                       BY_HANDLE_FILE_INFORMATION *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; */
-    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, struct _Py_stat_struct* result, ULONG *reparse_tag)
 {
     HANDLE hFindFile;
     WIN32_FIND_DATAW FileData;
@@ -2074,7 +2058,7 @@ 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);
+    _Py_find_data_to_stat(&FileData, result);
     return TRUE;
 }
 
@@ -2108,10 +2092,11 @@ 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;
+    BY_HANDLE_FILE_INFORMATION fileInfo = {0};
+    BY_HANDLE_FILE_INFORMATION* pFileInfo = NULL;
+    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 +2117,7 @@ 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, result, &tagInfo.ReparseTag)) {
                 /* Cannot read the parent directory. */
                 switch (GetLastError()) {
                 case ERROR_FILE_NOT_FOUND: /* File cannot be found */
@@ -2147,7 +2132,7 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
 
                 return -1;
             }
-            if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+            if (result->st_file_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                 if (traverse ||
                     !IsReparseTagNameSurrogate(tagInfo.ReparseTag)) {
                     /* The stat call has to traverse but cannot, so fail. */
@@ -2247,9 +2232,15 @@ win32_xstat_slow_impl(const wchar_t *path, struct _Py_stat_struct *result,
             }
         }
 
-        if (!GetFileInformationByHandle(hFile, &fileInfo) ||
-            !GetFileInformationByHandleEx(hFile, FileBasicInfo,
-                                          &basicInfo, sizeof(basicInfo))) {
+#ifdef MS_WINDOWS_DESKTOP
+        if (GetFileInformationByHandle(hFile, &fileInfo)) {
+            /* Successfully got fileInfo, so pass it along */
+            pFileInfo = &fileInfo;
+        }
+#endif
+
+        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 +2255,18 @@ 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);
+#ifdef MS_WINDOWS_DESKTOP
+    _Py_attribute_data_to_stat(pFileInfo, tagInfo.ReparseTag, &basicInfo, pIdInfo, result);
+#else
+    _Py_attribute_data_to_stat_UWP(&standardInfo, tagInfo.ReparseTag, &basicInfo, result);
+#endif
+    update_st_mode_from_path(path, basicInfo.FileAttributes, result);
 
 cleanup:
     if (hFile != INVALID_HANDLE_VALUE) {
@@ -16670,8 +16662,6 @@ static PyObject *
 DirEntry_from_find_data(PyObject *module, path_t *path, WIN32_FIND_DATAW *dataW)
 {
     DirEntry *entry;
-    BY_HANDLE_FILE_INFORMATION file_info;
-    ULONG reparse_tag;
     wchar_t *joined_path;
 
     PyObject *DirEntryType = get_posix_state(module)->DirEntryType;
@@ -16708,8 +16698,7 @@ 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);
+    _Py_find_data_to_stat(dataW, &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

@@ -1149,6 +1149,36 @@ _Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,
     result->st_file_attributes = info->dwFileAttributes;
 }
 
+void
+_Py_attribute_data_to_stat_UWP(FILE_STANDARD_INFO* standard_info, ULONG reparse_tag,
+                               FILE_BASIC_INFO* basic_info, struct _Py_stat_struct* result)
+{
+    memset(result, 0, sizeof(*result));
+    result->st_mode = attributes_to_mode(basic_info->FileAttributes);
+    result->st_size = standard_info->EndOfFile.QuadPart;
+    result->st_dev = 1;
+
+    /* st_ctime is deprecated, but we preserve the legacy value in our caller, not here */
+    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);
+
+    result->st_nlink = standard_info->NumberOfLinks;
+    result->st_ino = basic_info->CreationTime.QuadPart;
+
+    /* 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 (basic_info->FileAttributes & 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 = basic_info->FileAttributes;
+}
+
 void
 _Py_stat_basic_info_to_stat(FILE_STAT_BASIC_INFORMATION *info,
                             struct _Py_stat_struct *result)
@@ -1213,6 +1243,26 @@ _Py_stat_basic_info_to_stat(FILE_STAT_BASIC_INFORMATION *info,
     }
 }
 
+void
+_Py_find_data_to_stat(WIN32_FIND_DATAW* find_data, struct _Py_stat_struct* result)
+{
+    memset(result, 0, sizeof(*result));
+    result->st_mode = attributes_to_mode(find_data->dwFileAttributes);
+    FILE_TIME_to_time_t_nsec(&find_data->ftCreationTime, &result->st_ctime, &result->st_ctime_nsec);
+    FILE_TIME_to_time_t_nsec(&find_data->ftLastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
+    FILE_TIME_to_time_t_nsec(&find_data->ftLastAccessTime, &result->st_atime, &result->st_atime_nsec);
+    result->st_size = (((long long)find_data->nFileSizeHigh) << 32) | find_data->nFileSizeLow;
+
+    if (find_data->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
+        find_data->dwReserved0 == IO_REPARSE_TAG_SYMLINK) {
+        /* first clear the S_IFMT bits */
+        result->st_mode ^= (result->st_mode & S_IFMT);
+        /* now set the bits that make this a symlink */
+        result->st_mode |= S_IFLNK;
+    }
+    result->st_file_attributes = find_data->dwFileAttributes;
+}
+
 #endif
 
 /* Return information about a file.
@@ -1231,9 +1281,11 @@ 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;
+    BY_HANDLE_FILE_INFORMATION fileInfo = {0};
+    BY_HANDLE_FILE_INFORMATION* pFileInfo = NULL;
+    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 +1318,14 @@ _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
         return 0;
     }
 
-    if (!GetFileInformationByHandle(h, &info) ||
+#ifdef MS_WINDOWS_DESKTOP
+    if (GetFileInformationByHandle(h, &fileInfo)) {
+        /* Successfully got fileInfo, so pass it along */
+        pFileInfo = &fileInfo;
+    }
+#endif
+
+    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 +1338,11 @@ _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
         pIdInfo = NULL;
     }
 
-    _Py_attribute_data_to_stat(&info, 0, &basicInfo, pIdInfo, status);
+#ifdef MS_WINDOWS_DESKTOP
+    _Py_attribute_data_to_stat(pFileInfo, 0, &basicInfo, pIdInfo, status);
+#else
+    _Py_attribute_data_to_stat_UWP(&standardInfo, 0, &basicInfo, status);
+#endif
     return 0;
 #else
     return fstat(fd, status);