Rollup of 8 pull requests

compiler/rustc_error_codes/src/error_codes/E0658.md

@@ -3,10 +3,7 @@ An unstable feature was used.
 Erroneous code example:
 
 ```compile_fail,E0658
-#[repr(u128)] // error: use of unstable library feature 'repr128'
-enum Foo {
-    Bar(u64),
-}
+use std::intrinsics; // error: use of unstable library feature `core_intrinsics`
 ```
 
 If you're using a stable or a beta version of rustc, you won't be able to use
@@ -17,12 +14,9 @@ If you're using a nightly version of rustc, just add the corresponding feature
 to be able to use it:
 
 ```
-#![feature(repr128)]
+#![feature(core_intrinsics)]
 
-#[repr(u128)] // ok!
-enum Foo {
-    Bar(u64),
-}
+use std::intrinsics; // ok!
 ```
 
 [rustup]: https://rust-lang.github.io/rustup/concepts/channels.html

compiler/rustc_feature/src/accepted.rs

@@ -360,6 +360,8 @@ declare_features! (
     (accepted, relaxed_adts, "1.19.0", Some(35626)),
     /// Lessens the requirements for structs to implement `Unsize`.
     (accepted, relaxed_struct_unsize, "1.58.0", Some(81793)),
+    /// Allows the `#[repr(i128)]` attribute for enums.
+    (accepted, repr128, "CURRENT_RUSTC_VERSION", Some(56071)),
     /// Allows `repr(align(16))` struct attribute (RFC 1358).
     (accepted, repr_align, "1.25.0", Some(33626)),
     /// Allows using `#[repr(align(X))]` on enums with equivalent semantics

compiler/rustc_feature/src/unstable.rs

@@ -621,8 +621,6 @@ declare_features! (
     (incomplete, ref_pat_eat_one_layer_2024_structural, "1.81.0", Some(123076)),
     /// Allows using the `#[register_tool]` attribute.
     (unstable, register_tool, "1.41.0", Some(66079)),
-    /// Allows the `#[repr(i128)]` attribute for enums.
-    (incomplete, repr128, "1.16.0", Some(56071)),
     /// Allows `repr(simd)` and importing the various simd intrinsics.
     (unstable, repr_simd, "1.4.0", Some(27731)),
     /// Allows bounding the return type of AFIT/RPITIT.

compiler/rustc_hir_analysis/src/check/check.rs

@@ -18,7 +18,7 @@ use rustc_middle::middle::resolve_bound_vars::ResolvedArg;
 use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::ty::error::TypeErrorToStringExt;
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
-use rustc_middle::ty::util::{Discr, IntTypeExt};
+use rustc_middle::ty::util::Discr;
 use rustc_middle::ty::{
     AdtDef, BottomUpFolder, GenericArgKind, RegionKind, TypeFoldable, TypeSuperVisitable,
     TypeVisitable, TypeVisitableExt, fold_regions,
@@ -1385,19 +1385,6 @@ fn check_enum(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         );
     }
 
-    let repr_type_ty = def.repr().discr_type().to_ty(tcx);
-    if repr_type_ty == tcx.types.i128 || repr_type_ty == tcx.types.u128 {
-        if !tcx.features().repr128() {
-            feature_err(
-                &tcx.sess,
-                sym::repr128,
-                tcx.def_span(def_id),
-                "repr with 128-bit type is unstable",
-            )
-            .emit();
-        }
-    }
-
     for v in def.variants() {
         if let ty::VariantDiscr::Explicit(discr_def_id) = v.discr {
             tcx.ensure_ok().typeck(discr_def_id.expect_local());

compiler/rustc_span/src/symbol.rs

@@ -2074,6 +2074,9 @@ symbols! {
         sym,
         sync,
         synthetic,
+        sys_mutex_lock,
+        sys_mutex_try_lock,
+        sys_mutex_unlock,
         t32,
         target,
         target_abi,

library/core/src/ffi/c_str.rs

@@ -632,6 +632,30 @@ impl CStr {
         // instead of doing it afterwards.
         str::from_utf8(self.to_bytes())
     }
+
+    /// Returns an object that implements [`Display`] for safely printing a [`CStr`] that may
+    /// contain non-Unicode data.
+    ///
+    /// Behaves as if `self` were first lossily converted to a `str`, with invalid UTF-8 presented
+    /// as the Unicode replacement character: �.
+    ///
+    /// [`Display`]: fmt::Display
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(cstr_display)]
+    ///
+    /// let cstr = c"Hello, world!";
+    /// println!("{}", cstr.display());
+    /// ```
+    #[unstable(feature = "cstr_display", issue = "139984")]
+    #[must_use = "this does not display the `CStr`; \
+                  it returns an object that can be displayed"]
+    #[inline]
+    pub fn display(&self) -> impl fmt::Display {
+        crate::bstr::ByteStr::from_bytes(self.to_bytes())
+    }
 }
 
 // `.to_bytes()` representations are compared instead of the inner `[c_char]`s,

library/core/src/intrinsics/mod.rs

@@ -2285,12 +2285,6 @@ pub fn round_ties_even_f16(x: f16) -> f16;
 #[rustc_nounwind]
 pub fn round_ties_even_f32(x: f32) -> f32;
 
-/// Provided for compatibility with stdarch. DO NOT USE.
-#[inline(always)]
-pub unsafe fn rintf32(x: f32) -> f32 {
-    round_ties_even_f32(x)
-}
-
 /// Returns the nearest integer to an `f64`. Rounds half-way cases to the number with an even
 /// least significant digit.
 ///
@@ -2300,12 +2294,6 @@ pub unsafe fn rintf32(x: f32) -> f32 {
 #[rustc_nounwind]
 pub fn round_ties_even_f64(x: f64) -> f64;
 
-/// Provided for compatibility with stdarch. DO NOT USE.
-#[inline(always)]
-pub unsafe fn rintf64(x: f64) -> f64 {
-    round_ties_even_f64(x)
-}
-
 /// Returns the nearest integer to an `f128`. Rounds half-way cases to the number with an even
 /// least significant digit.
 ///

library/coretests/tests/ffi/cstr.rs

@@ -19,3 +19,9 @@ fn debug() {
     let s = c"abc\x01\x02\n\xE2\x80\xA6\xFF";
     assert_eq!(format!("{s:?}"), r#""abc\x01\x02\n\xe2\x80\xa6\xff""#);
 }
+
+#[test]
+fn display() {
+    let s = c"\xf0\x28\x8c\xbc";
+    assert_eq!(format!("{}", s.display()), "�(��");
+}

library/coretests/tests/lib.rs

@@ -23,6 +23,7 @@
 #![feature(core_io_borrowed_buf)]
 #![feature(core_private_bignum)]
 #![feature(core_private_diy_float)]
+#![feature(cstr_display)]
 #![feature(dec2flt)]
 #![feature(duration_constants)]
 #![feature(duration_constructors)]

library/std/src/fs.rs

@@ -1311,9 +1311,39 @@ impl Write for &File {
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Seek for &File {
+    /// Seek to an offset, in bytes in a file.
+    ///
+    /// See [`Seek::seek`] docs for more info.
+    ///
+    /// # Platform-specific behavior
+    ///
+    /// This function currently corresponds to the `lseek64` function on Unix
+    /// and the `SetFilePointerEx` function on Windows. Note that this [may
+    /// change in the future][changes].
+    ///
+    /// [changes]: io#platform-specific-behavior
     fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
         self.inner.seek(pos)
     }
+
+    /// Returns the length of this file (in bytes).
+    ///
+    /// See [`Seek::stream_len`] docs for more info.
+    ///
+    /// # Platform-specific behavior
+    ///
+    /// This function currently corresponds to the `statx` function on Linux
+    /// (with fallbacks) and the `GetFileSizeEx` function on Windows. Note that
+    /// this [may change in the future][changes].
+    ///
+    /// [changes]: io#platform-specific-behavior
+    fn stream_len(&mut self) -> io::Result<u64> {
+        if let Some(result) = self.inner.size() {
+            return result;
+        }
+        io::stream_len_default(self)
+    }
+
     fn stream_position(&mut self) -> io::Result<u64> {
         self.inner.tell()
     }
@@ -1363,6 +1393,9 @@ impl Seek for File {
     fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
         (&*self).seek(pos)
     }
+    fn stream_len(&mut self) -> io::Result<u64> {
+        (&*self).stream_len()
+    }
     fn stream_position(&mut self) -> io::Result<u64> {
         (&*self).stream_position()
     }
@@ -1412,6 +1445,9 @@ impl Seek for Arc<File> {
     fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
         (&**self).seek(pos)
     }
+    fn stream_len(&mut self) -> io::Result<u64> {
+        (&**self).stream_len()
+    }
     fn stream_position(&mut self) -> io::Result<u64> {
         (&**self).stream_position()
     }

library/std/src/io/mod.rs

@@ -2028,7 +2028,7 @@ pub trait Seek {
 
     /// Returns the length of this stream (in bytes).
     ///
-    /// This method is implemented using up to three seek operations. If this
+    /// The default implementation uses up to three seek operations. If this
     /// method returns successfully, the seek position is unchanged (i.e. the
     /// position before calling this method is the same as afterwards).
     /// However, if this method returns an error, the seek position is
@@ -2062,16 +2062,7 @@ pub trait Seek {
     /// ```
     #[unstable(feature = "seek_stream_len", issue = "59359")]
     fn stream_len(&mut self) -> Result<u64> {
-        let old_pos = self.stream_position()?;
-        let len = self.seek(SeekFrom::End(0))?;
-
-        // Avoid seeking a third time when we were already at the end of the
-        // stream. The branch is usually way cheaper than a seek operation.
-        if old_pos != len {
-            self.seek(SeekFrom::Start(old_pos))?;
-        }
-
-        Ok(len)
+        stream_len_default(self)
     }
 
     /// Returns the current seek position from the start of the stream.
@@ -2132,6 +2123,19 @@ pub trait Seek {
     }
 }
 
+pub(crate) fn stream_len_default<T: Seek + ?Sized>(self_: &mut T) -> Result<u64> {
+    let old_pos = self_.stream_position()?;
+    let len = self_.seek(SeekFrom::End(0))?;
+
+    // Avoid seeking a third time when we were already at the end of the
+    // stream. The branch is usually way cheaper than a seek operation.
+    if old_pos != len {
+        self_.seek(SeekFrom::Start(old_pos))?;
+    }
+
+    Ok(len)
+}
+
 /// Enumeration of possible methods to seek within an I/O object.
 ///
 /// It is used by the [`Seek`] trait.

library/std/src/path.rs

@@ -2746,15 +2746,30 @@ impl Path {
     /// # Examples
     ///
     /// ```
-    /// use std::path::{Path, PathBuf};
+    /// use std::path::Path;
     ///
     /// let path = Path::new("foo.rs");
-    /// assert_eq!(path.with_extension("txt"), PathBuf::from("foo.txt"));
+    /// assert_eq!(path.with_extension("txt"), Path::new("foo.txt"));
+    /// assert_eq!(path.with_extension(""), Path::new("foo"));
+    /// ```
+    ///
+    /// Handling multiple extensions:
+    ///
+    /// ```
+    /// use std::path::Path;
     ///
     /// let path = Path::new("foo.tar.gz");
-    /// assert_eq!(path.with_extension(""), PathBuf::from("foo.tar"));
-    /// assert_eq!(path.with_extension("xz"), PathBuf::from("foo.tar.xz"));
-    /// assert_eq!(path.with_extension("").with_extension("txt"), PathBuf::from("foo.txt"));
+    /// assert_eq!(path.with_extension("xz"), Path::new("foo.tar.xz"));
+    /// assert_eq!(path.with_extension("").with_extension("txt"), Path::new("foo.txt"));
+    /// ```
+    ///
+    /// Adding an extension where one did not exist:
+    ///
+    /// ```
+    /// use std::path::Path;
+    ///
+    /// let path = Path::new("foo");
+    /// assert_eq!(path.with_extension("rs"), Path::new("foo.rs"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn with_extension<S: AsRef<OsStr>>(&self, extension: S) -> PathBuf {

library/std/src/sys/fs/hermit.rs

@@ -422,6 +422,10 @@ impl File {
         self.0.seek(pos)
     }
 
+    pub fn size(&self) -> Option<io::Result<u64>> {
+        None
+    }
+
     pub fn tell(&self) -> io::Result<u64> {
         self.0.tell()
     }

library/std/src/sys/fs/solid.rs

@@ -459,6 +459,10 @@ impl File {
         self.tell()
     }
 
+    pub fn size(&self) -> Option<io::Result<u64>> {
+        None
+    }
+
     pub fn tell(&self) -> io::Result<u64> {
         unsafe {
             let mut out_offset = MaybeUninit::uninit();

library/std/src/sys/fs/unix.rs

@@ -1464,6 +1464,15 @@ impl File {
         Ok(n as u64)
     }
 
+    pub fn size(&self) -> Option<io::Result<u64>> {
+        match self.file_attr().map(|attr| attr.size()) {
+            // Fall back to default implementation if the returned size is 0,
+            // we might be in a proc mount.
+            Ok(0) => None,
+            result => Some(result),
+        }
+    }
+
     pub fn tell(&self) -> io::Result<u64> {
         self.seek(SeekFrom::Current(0))
     }

library/std/src/sys/fs/unsupported.rs

@@ -259,6 +259,10 @@ impl File {
         self.0
     }
 
+    pub fn size(&self) -> Option<io::Result<u64>> {
+        self.0
+    }
+
     pub fn tell(&self) -> io::Result<u64> {
         self.0
     }

library/std/src/sys/fs/wasi.rs

@@ -516,6 +516,10 @@ impl File {
         self.fd.seek(pos)
     }
 
+    pub fn size(&self) -> Option<io::Result<u64>> {
+        None
+    }
+
     pub fn tell(&self) -> io::Result<u64> {
         self.fd.tell()
     }

library/std/src/sys/fs/windows.rs

@@ -616,6 +616,14 @@ impl File {
         Ok(newpos as u64)
     }
 
+    pub fn size(&self) -> Option<io::Result<u64>> {
+        let mut result = 0;
+        Some(
+            cvt(unsafe { c::GetFileSizeEx(self.handle.as_raw_handle(), &mut result) })
+                .map(|_| result as u64),
+        )
+    }
+
     pub fn tell(&self) -> io::Result<u64> {
         self.seek(SeekFrom::Current(0))
     }

library/std/src/sys/pal/windows/c/bindings.txt

@@ -2156,6 +2156,7 @@ GetExitCodeProcess
 GetFileAttributesW
 GetFileInformationByHandle
 GetFileInformationByHandleEx
+GetFileSizeEx
 GetFileType
 GETFINALPATHNAMEBYHANDLE_FLAGS
 GetFinalPathNameByHandleW

library/std/src/sys/pal/windows/c/windows_sys.rs

@@ -44,6 +44,7 @@ windows_targets::link!("kernel32.dll" "system" fn GetExitCodeProcess(hprocess :
 windows_targets::link!("kernel32.dll" "system" fn GetFileAttributesW(lpfilename : PCWSTR) -> u32);
 windows_targets::link!("kernel32.dll" "system" fn GetFileInformationByHandle(hfile : HANDLE, lpfileinformation : *mut BY_HANDLE_FILE_INFORMATION) -> BOOL);
 windows_targets::link!("kernel32.dll" "system" fn GetFileInformationByHandleEx(hfile : HANDLE, fileinformationclass : FILE_INFO_BY_HANDLE_CLASS, lpfileinformation : *mut core::ffi::c_void, dwbuffersize : u32) -> BOOL);
+windows_targets::link!("kernel32.dll" "system" fn GetFileSizeEx(hfile : HANDLE, lpfilesize : *mut i64) -> BOOL);
 windows_targets::link!("kernel32.dll" "system" fn GetFileType(hfile : HANDLE) -> FILE_TYPE);
 windows_targets::link!("kernel32.dll" "system" fn GetFinalPathNameByHandleW(hfile : HANDLE, lpszfilepath : PWSTR, cchfilepath : u32, dwflags : GETFINALPATHNAMEBYHANDLE_FLAGS) -> u32);
 windows_targets::link!("kernel32.dll" "system" fn GetFullPathNameW(lpfilename : PCWSTR, nbufferlength : u32, lpbuffer : PWSTR, lpfilepart : *mut PWSTR) -> u32);