rust-lang · bors · Dec 22, 2024 · Sep 30, 2024 · Sep 30, 2024 · Oct 16, 2024
diff --git a/compiler/rustc_index/Cargo.toml b/compiler/rustc_index/Cargo.toml
@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-rustc_index_macros = { path = "../rustc_index_macros", default-features = false }
+rustc_index_macros = { path = "../rustc_index_macros" }
 rustc_macros = { path = "../rustc_macros", optional = true }
 rustc_serialize = { path = "../rustc_serialize", optional = true }
 smallvec = "1.8.1"

diff --git a/compiler/rustc_index_macros/Cargo.toml b/compiler/rustc_index_macros/Cargo.toml
@@ -12,5 +12,4 @@ proc-macro2 = "1"
 quote = "1"
 
 [features]
-default = ["nightly"]
 nightly = []
diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs
@@ -12,14 +12,17 @@ impl<T: ?Sized> *const T {
     /// Therefore, two pointers that are null may still not compare equal to
     /// each other.
     ///
-    /// ## Behavior during const evaluation
+    /// # Panics during const evaluation
     ///
-    /// When this function is used during const evaluation, it may return `false` for pointers
-    /// that turn out to be null at runtime. Specifically, when a pointer to some memory
-    /// is offset beyond its bounds in such a way that the resulting pointer is null,
-    /// the function will still return `false`. There is no way for CTFE to know
-    /// the absolute position of that memory, so we cannot tell if the pointer is
-    /// null or not.
+    /// If this method is used during const evaluation, and `self` is a pointer
+    /// that is offset beyond the bounds of the memory it initially pointed to,
+    /// then there might not be enough information to determine whether the
+    /// pointer is null. This is because the absolute address in memory is not
+    /// known at compile time. If the nullness of the pointer cannot be
+    /// determined, this method will panic.
+    ///
+    /// In-bounds pointers are never null, so the method will never panic for
+    /// such pointers.
     ///
     /// # Examples
     ///
@@ -254,6 +257,13 @@ impl<T: ?Sized> *const T {
     /// When calling this method, you have to ensure that *either* the pointer is null *or*
     /// the pointer is [convertible to a reference](crate::ptr#pointer-to-reference-conversion).
     ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null
+    ///
     /// # Examples
     ///
     /// ```
@@ -331,6 +341,13 @@ impl<T: ?Sized> *const T {
     /// When calling this method, you have to ensure that *either* the pointer is null *or*
     /// the pointer is [convertible to a reference](crate::ptr#pointer-to-reference-conversion).
     ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null
+    ///
     /// # Examples
     ///
     /// ```
@@ -1607,6 +1624,13 @@ impl<T> *const [T] {
     ///
     /// [valid]: crate::ptr#safety
     /// [allocated object]: crate::ptr#allocated-object
+    ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null
     #[inline]
     #[unstable(feature = "ptr_as_uninit", issue = "75402")]
     pub const unsafe fn as_uninit_slice<'a>(self) -> Option<&'a [MaybeUninit<T>]> {

diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs
@@ -12,14 +12,17 @@ impl<T: ?Sized> *mut T {
     /// Therefore, two pointers that are null may still not compare equal to
     /// each other.
     ///
-    /// ## Behavior during const evaluation
+    /// # Panics during const evaluation
     ///
-    /// When this function is used during const evaluation, it may return `false` for pointers
-    /// that turn out to be null at runtime. Specifically, when a pointer to some memory
-    /// is offset beyond its bounds in such a way that the resulting pointer is null,
-    /// the function will still return `false`. There is no way for CTFE to know
-    /// the absolute position of that memory, so we cannot tell if the pointer is
-    /// null or not.
+    /// If this method is used during const evaluation, and `self` is a pointer
+    /// that is offset beyond the bounds of the memory it initially pointed to,
+    /// then there might not be enough information to determine whether the
+    /// pointer is null. This is because the absolute address in memory is not
+    /// known at compile time. If the nullness of the pointer cannot be
+    /// determined, this method will panic.
+    ///
+    /// In-bounds pointers are never null, so the method will never panic for
+    /// such pointers.
     ///
     /// # Examples
     ///
@@ -243,6 +246,13 @@ impl<T: ?Sized> *mut T {
     /// When calling this method, you have to ensure that *either* the pointer is null *or*
     /// the pointer is [convertible to a reference](crate::ptr#pointer-to-reference-conversion).
     ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null-1
+    ///
     /// # Examples
     ///
     /// ```
@@ -327,6 +337,13 @@ impl<T: ?Sized> *mut T {
     /// Note that because the created reference is to `MaybeUninit<T>`, the
     /// source pointer can point to uninitialized memory.
     ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null-1
+    ///
     /// # Examples
     ///
     /// ```
@@ -590,6 +607,12 @@ impl<T: ?Sized> *mut T {
     /// the pointer is null *or*
     /// the pointer is [convertible to a reference](crate::ptr#pointer-to-reference-conversion).
     ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null-1
     ///
     /// # Examples
     ///
@@ -673,6 +696,13 @@ impl<T: ?Sized> *mut T {
     ///
     /// When calling this method, you have to ensure that *either* the pointer is null *or*
     /// the pointer is [convertible to a reference](crate::ptr#pointer-to-reference-conversion).
+    ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null-1
     #[inline]
     #[unstable(feature = "ptr_as_uninit", issue = "75402")]
     pub const unsafe fn as_uninit_mut<'a>(self) -> Option<&'a mut MaybeUninit<T>>
@@ -1949,6 +1979,13 @@ impl<T> *mut [T] {
     ///
     /// [valid]: crate::ptr#safety
     /// [allocated object]: crate::ptr#allocated-object
+    ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null-1
     #[inline]
     #[unstable(feature = "ptr_as_uninit", issue = "75402")]
     pub const unsafe fn as_uninit_slice<'a>(self) -> Option<&'a [MaybeUninit<T>]> {
@@ -2000,6 +2037,13 @@ impl<T> *mut [T] {
     ///
     /// [valid]: crate::ptr#safety
     /// [allocated object]: crate::ptr#allocated-object
+    ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: #method.is_null-1
     #[inline]
     #[unstable(feature = "ptr_as_uninit", issue = "75402")]
     pub const unsafe fn as_uninit_slice_mut<'a>(self) -> Option<&'a mut [MaybeUninit<T>]> {

diff --git a/library/core/src/ptr/non_null.rs b/library/core/src/ptr/non_null.rs
@@ -204,6 +204,13 @@ impl<T: ?Sized> NonNull<T> {
 
     /// Creates a new `NonNull` if `ptr` is non-null.
     ///
+    /// # Panics during const evaluation
+    ///
+    /// This method will panic during const evaluation if the pointer cannot be
+    /// determined to be null or not. See [`is_null`] for more information.
+    ///
+    /// [`is_null`]: ../primitive.pointer.html#method.is_null-1
+    ///
     /// # Examples
     ///
     /// ```

diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
@@ -2397,12 +2397,14 @@ pub fn symlink_metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> {
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to the `rename` function on Unix
-/// and the `MoveFileEx` function with the `MOVEFILE_REPLACE_EXISTING` flag on Windows.
+/// and the `SetFileInformationByHandle` function on Windows.
 ///
 /// Because of this, the behavior when both `from` and `to` exist differs. On
 /// Unix, if `from` is a directory, `to` must also be an (empty) directory. If
-/// `from` is not a directory, `to` must also be not a directory. In contrast,
-/// on Windows, `from` can be anything, but `to` must *not* be a directory.
+/// `from` is not a directory, `to` must also be not a directory. The behavior
+/// on Windows is the same on Windows 10 1607 and higher if `FileRenameInfoEx`
+/// is supported by the filesystem; otherwise, `from` can be anything, but
+/// `to` must *not* be a directory.
 ///
 /// Note that, this [may change in the future][changes].
 ///

diff --git a/library/std/src/fs/tests.rs b/library/std/src/fs/tests.rs
@@ -1912,3 +1912,44 @@ fn test_hidden_file_truncation() {
     let metadata = file.metadata().unwrap();
     assert_eq!(metadata.len(), 0);
 }
+
+#[cfg(windows)]
+#[test]
+fn test_rename_file_over_open_file() {
+    // Make sure that std::fs::rename works if the target file is already opened with FILE_SHARE_DELETE. See #123985.
+    let tmpdir = tmpdir();
+
+    // Create source with test data to read.
+    let source_path = tmpdir.join("source_file.txt");
+    fs::write(&source_path, b"source hello world").unwrap();
+
+    // Create target file with test data to read;
+    let target_path = tmpdir.join("target_file.txt");
+    fs::write(&target_path, b"target hello world").unwrap();
+
+    // Open target file
+    let target_file = fs::File::open(&target_path).unwrap();
+
+    // Rename source
+    fs::rename(source_path, &target_path).unwrap();
+
+    core::mem::drop(target_file);
+    assert_eq!(fs::read(target_path).unwrap(), b"source hello world");
+}
+
+#[test]
+#[cfg(windows)]
+fn test_rename_directory_to_non_empty_directory() {
+    // Renaming a directory over a non-empty existing directory should fail on Windows.
+    let tmpdir: TempDir = tmpdir();
+
+    let source_path = tmpdir.join("source_directory");
+    let target_path = tmpdir.join("target_directory");
+
+    fs::create_dir(&source_path).unwrap();
+    fs::create_dir(&target_path).unwrap();
+
+    fs::write(target_path.join("target_file.txt"), b"target hello world").unwrap();
+
+    error!(fs::rename(source_path, target_path), 145); // ERROR_DIR_NOT_EMPTY
+}
diff --git a/library/std/src/sys/pal/windows/c/bindings.txt b/library/std/src/sys/pal/windows/c/bindings.txt
@@ -2295,6 +2295,7 @@ Windows.Win32.Storage.FileSystem.FILE_NAME_OPENED
 Windows.Win32.Storage.FileSystem.FILE_READ_ATTRIBUTES
 Windows.Win32.Storage.FileSystem.FILE_READ_DATA
 Windows.Win32.Storage.FileSystem.FILE_READ_EA
+Windows.Win32.Storage.FileSystem.FILE_RENAME_INFO
 Windows.Win32.Storage.FileSystem.FILE_SHARE_DELETE
 Windows.Win32.Storage.FileSystem.FILE_SHARE_MODE
 Windows.Win32.Storage.FileSystem.FILE_SHARE_NONE
@@ -2603,5 +2604,7 @@ Windows.Win32.System.Threading.WaitForMultipleObjects
 Windows.Win32.System.Threading.WaitForSingleObject
 Windows.Win32.System.Threading.WakeAllConditionVariable
 Windows.Win32.System.Threading.WakeConditionVariable
+Windows.Win32.System.WindowsProgramming.FILE_RENAME_FLAG_POSIX_SEMANTICS
+Windows.Win32.System.WindowsProgramming.FILE_RENAME_FLAG_REPLACE_IF_EXISTS
 Windows.Win32.System.WindowsProgramming.PROGRESS_CONTINUE
 Windows.Win32.UI.Shell.GetUserProfileDirectoryW
diff --git a/library/std/src/sys/pal/windows/c/windows_sys.rs b/library/std/src/sys/pal/windows/c/windows_sys.rs
@@ -2472,6 +2472,22 @@ pub const FILE_RANDOM_ACCESS: NTCREATEFILE_CREATE_OPTIONS = 2048u32;
 pub const FILE_READ_ATTRIBUTES: FILE_ACCESS_RIGHTS = 128u32;
 pub const FILE_READ_DATA: FILE_ACCESS_RIGHTS = 1u32;
 pub const FILE_READ_EA: FILE_ACCESS_RIGHTS = 8u32;
+pub const FILE_RENAME_FLAG_POSIX_SEMANTICS: u32 = 2u32;
+pub const FILE_RENAME_FLAG_REPLACE_IF_EXISTS: u32 = 1u32;
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct FILE_RENAME_INFO {
+    pub Anonymous: FILE_RENAME_INFO_0,
+    pub RootDirectory: HANDLE,
+    pub FileNameLength: u32,
+    pub FileName: [u16; 1],
+}
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub union FILE_RENAME_INFO_0 {
+    pub ReplaceIfExists: BOOLEAN,
+    pub Flags: u32,
+}
 pub const FILE_RESERVE_OPFILTER: NTCREATEFILE_CREATE_OPTIONS = 1048576u32;
 pub const FILE_SEQUENTIAL_ONLY: NTCREATEFILE_CREATE_OPTIONS = 4u32;
 pub const FILE_SESSION_AWARE: NTCREATEFILE_CREATE_OPTIONS = 262144u32;