Auto merge of rust-lang#139845 - Zalathar:rollup-u5u5y1v, r=Zalathar

Rollup of 17 pull requests

Successful merges:

 - rust-lang#138374 (Enable contracts for const functions)
 - rust-lang#138380 (ci: add runners for vanilla LLVM 20)
 - rust-lang#138393 (Allow const patterns of matches to contain pattern types)
 - rust-lang#139517 (std: sys: process: uefi: Use NULL stdin by default)
 - rust-lang#139554 (std: add Output::exit_ok)
 - rust-lang#139660 (compiletest: Add an experimental new executor to replace libtest)
 - rust-lang#139669 (Overhaul `AssocItem`)
 - rust-lang#139671 (Proc macro span API redesign: Replace proc_macro::SourceFile by Span::{file, local_file})
 - rust-lang#139750 (std/thread: Use default stack size from menuconfig for NuttX)
 - rust-lang#139772 (Remove `hir::Map`)
 - rust-lang#139785 (Let CStrings be either 1 or 2 byte aligned.)
 - rust-lang#139789 (do not unnecessarily leak auto traits in item bounds)
 - rust-lang#139791 (drop global where-bounds before merging candidates)
 - rust-lang#139798 (normalize: prefer `ParamEnv` over `AliasBound` candidates)
 - rust-lang#139822 (Fix: Map EOPNOTSUPP to ErrorKind::Unsupported on Unix)
 - rust-lang#139833 (Fix some HIR pretty-printing problems)
 - rust-lang#139836 (Basic tests of MPMC receiver cloning)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

core/src/contracts.rs

@@ -2,19 +2,23 @@
 
 pub use crate::macros::builtin::{contracts_ensures as ensures, contracts_requires as requires};
 
-/// Emitted by rustc as a desugaring of `#[ensures(PRED)] fn foo() -> R { ... [return R;] ... }`
-/// into: `fn foo() { let _check = build_check_ensures(|ret| PRED) ... [return _check(R);] ... }`
-/// (including the implicit return of the tail expression, if any).
+/// This is an identity function used as part of the desugaring of the `#[ensures]` attribute.
+///
+/// This is an existing hack to allow users to omit the type of the return value in their ensures
+/// attribute.
+///
+/// Ideally, rustc should be able to generate the type annotation.
+/// The existing lowering logic makes it rather hard to add the explicit type annotation,
+/// while the function call is fairly straight forward.
 #[unstable(feature = "contracts_internals", issue = "128044" /* compiler-team#759 */)]
+// Similar to `contract_check_requires`, we need to use the user-facing
+// `contracts` feature rather than the perma-unstable `contracts_internals`.
+// Const-checking doesn't honor allow_internal_unstable logic used by contract expansion.
+#[rustc_const_unstable(feature = "contracts", issue = "128044")]
 #[lang = "contract_build_check_ensures"]
-#[track_caller]
-pub fn build_check_ensures<Ret, C>(cond: C) -> impl (Fn(Ret) -> Ret) + Copy
+pub const fn build_check_ensures<Ret, C>(cond: C) -> C
 where
-    C: for<'a> Fn(&'a Ret) -> bool + Copy + 'static,
+    C: Fn(&Ret) -> bool + Copy + 'static,
 {
-    #[track_caller]
-    move |ret| {
-        crate::intrinsics::contract_check_ensures(&ret, cond);
-        ret
-    }
+    cond
 }

core/src/intrinsics/mod.rs

@@ -3402,20 +3402,62 @@ pub const fn contract_checks() -> bool {
 ///
 /// By default, if `contract_checks` is enabled, this will panic with no unwind if the condition
 /// returns false.
-#[unstable(feature = "contracts_internals", issue = "128044" /* compiler-team#759 */)]
+///
+/// Note that this function is a no-op during constant evaluation.
+#[unstable(feature = "contracts_internals", issue = "128044")]
+// Calls to this function get inserted by an AST expansion pass, which uses the equivalent of
+// `#[allow_internal_unstable]` to allow using `contracts_internals` functions. Const-checking
+// doesn't honor `#[allow_internal_unstable]`, so for the const feature gate we use the user-facing
+// `contracts` feature rather than the perma-unstable `contracts_internals`
+#[rustc_const_unstable(feature = "contracts", issue = "128044")]
 #[lang = "contract_check_requires"]
 #[rustc_intrinsic]
-pub fn contract_check_requires<C: Fn() -> bool>(cond: C) {
-    if contract_checks() && !cond() {
-        // Emit no unwind panic in case this was a safety requirement.
-        crate::panicking::panic_nounwind("failed requires check");
-    }
+pub const fn contract_check_requires<C: Fn() -> bool + Copy>(cond: C) {
+    const_eval_select!(
+        @capture[C: Fn() -> bool + Copy] { cond: C } :
+        if const {
+                // Do nothing
+        } else {
+            if contract_checks() && !cond() {
+                // Emit no unwind panic in case this was a safety requirement.
+                crate::panicking::panic_nounwind("failed requires check");
+            }
+        }
+    )
 }
 
 /// Check if the post-condition `cond` has been met.
 ///
 /// By default, if `contract_checks` is enabled, this will panic with no unwind if the condition
 /// returns false.
+///
+/// Note that this function is a no-op during constant evaluation.
+#[cfg(not(bootstrap))]
+#[unstable(feature = "contracts_internals", issue = "128044")]
+// Similar to `contract_check_requires`, we need to use the user-facing
+// `contracts` feature rather than the perma-unstable `contracts_internals`.
+// Const-checking doesn't honor allow_internal_unstable logic used by contract expansion.
+#[rustc_const_unstable(feature = "contracts", issue = "128044")]
+#[lang = "contract_check_ensures"]
+#[rustc_intrinsic]
+pub const fn contract_check_ensures<C: Fn(&Ret) -> bool + Copy, Ret>(cond: C, ret: Ret) -> Ret {
+    const_eval_select!(
+        @capture[C: Fn(&Ret) -> bool + Copy, Ret] { cond: C, ret: Ret } -> Ret :
+        if const {
+            // Do nothing
+            ret
+        } else {
+            if contract_checks() && !cond(&ret) {
+                // Emit no unwind panic in case this was a safety requirement.
+                crate::panicking::panic_nounwind("failed ensures check");
+            }
+            ret
+        }
+    )
+}
+
+/// This is the old version of contract_check_ensures kept here for bootstrap only.
+#[cfg(bootstrap)]
 #[unstable(feature = "contracts_internals", issue = "128044" /* compiler-team#759 */)]
 #[rustc_intrinsic]
 pub fn contract_check_ensures<'a, Ret, C: Fn(&'a Ret) -> bool>(ret: &'a Ret, cond: C) {

core/src/lib.rs

@@ -101,7 +101,6 @@
 #![feature(bstr)]
 #![feature(bstr_internals)]
 #![feature(cfg_match)]
-#![feature(closure_track_caller)]
 #![feature(const_carrying_mul_add)]
 #![feature(const_eval_select)]
 #![feature(core_intrinsics)]

proc_macro/src/bridge/client.rs

@@ -111,12 +111,6 @@ impl Clone for TokenStream {
     }
 }
 
-impl Clone for SourceFile {
-    fn clone(&self) -> Self {
-        self.clone()
-    }
-}
-
 impl Span {
     pub(crate) fn def_site() -> Span {
         Bridge::with(|bridge| bridge.globals.def_site)

proc_macro/src/bridge/mod.rs

@@ -81,23 +81,17 @@ macro_rules! with_api {
                     $self: $S::TokenStream
                 ) -> Vec<TokenTree<$S::TokenStream, $S::Span, $S::Symbol>>;
             },
-            SourceFile {
-                fn drop($self: $S::SourceFile);
-                fn clone($self: &$S::SourceFile) -> $S::SourceFile;
-                fn eq($self: &$S::SourceFile, other: &$S::SourceFile) -> bool;
-                fn path($self: &$S::SourceFile) -> String;
-                fn is_real($self: &$S::SourceFile) -> bool;
-            },
             Span {
                 fn debug($self: $S::Span) -> String;
-                fn source_file($self: $S::Span) -> $S::SourceFile;
                 fn parent($self: $S::Span) -> Option<$S::Span>;
                 fn source($self: $S::Span) -> $S::Span;
                 fn byte_range($self: $S::Span) -> Range<usize>;
                 fn start($self: $S::Span) -> $S::Span;
                 fn end($self: $S::Span) -> $S::Span;
                 fn line($self: $S::Span) -> usize;
                 fn column($self: $S::Span) -> usize;
+                fn file($self: $S::Span) -> String;
+                fn local_file($self: $S::Span) -> Option<String>;
                 fn join($self: $S::Span, other: $S::Span) -> Option<$S::Span>;
                 fn subspan($self: $S::Span, start: Bound<usize>, end: Bound<usize>) -> Option<$S::Span>;
                 fn resolved_at($self: $S::Span, at: $S::Span) -> $S::Span;
@@ -120,7 +114,6 @@ macro_rules! with_api_handle_types {
             'owned:
             FreeFunctions,
             TokenStream,
-            SourceFile,
 
             'interned:
             Span,

proc_macro/src/bridge/server.rs

@@ -82,7 +82,6 @@ with_api_handle_types!(define_server_handles);
 pub trait Types {
     type FreeFunctions: 'static;
     type TokenStream: 'static + Clone;
-    type SourceFile: 'static + Clone;
     type Span: 'static + Copy + Eq + Hash;
     type Symbol: 'static;
 }

proc_macro/src/lib.rs

@@ -491,12 +491,6 @@ impl Span {
         Span(bridge::client::Span::mixed_site())
     }
 
-    /// The original source file into which this span points.
-    #[unstable(feature = "proc_macro_span", issue = "54725")]
-    pub fn source_file(&self) -> SourceFile {
-        SourceFile(self.0.source_file())
-    }
-
     /// The `Span` for the tokens in the previous macro expansion from which
     /// `self` was generated from, if any.
     #[unstable(feature = "proc_macro_span", issue = "54725")]
@@ -546,6 +540,25 @@ impl Span {
         self.0.column()
     }
 
+    /// The path to the source file in which this span occurs, for display purposes.
+    ///
+    /// This might not correspond to a valid file system path.
+    /// It might be remapped, or might be an artificial path such as `"<macro expansion>"`.
+    #[unstable(feature = "proc_macro_span", issue = "54725")]
+    pub fn file(&self) -> String {
+        self.0.file()
+    }
+
+    /// The path to the source file in which this span occurs on disk.
+    ///
+    /// This is the actual path on disk. It is unaffected by path remapping.
+    ///
+    /// This path should not be embedded in the output of the macro; prefer `file()` instead.
+    #[unstable(feature = "proc_macro_span", issue = "54725")]
+    pub fn local_file(&self) -> Option<PathBuf> {
+        self.0.local_file().map(|s| PathBuf::from(s))
+    }
+
     /// Creates a new span encompassing `self` and `other`.
     ///
     /// Returns `None` if `self` and `other` are from different files.
@@ -614,58 +627,6 @@ impl fmt::Debug for Span {
     }
 }
 
-/// The source file of a given `Span`.
-#[unstable(feature = "proc_macro_span", issue = "54725")]
-#[derive(Clone)]
-pub struct SourceFile(bridge::client::SourceFile);
-
-impl SourceFile {
-    /// Gets the path to this source file.
-    ///
-    /// ### Note
-    /// If the code span associated with this `SourceFile` was generated by an external macro, this
-    /// macro, this might not be an actual path on the filesystem. Use [`is_real`] to check.
-    ///
-    /// Also note that even if `is_real` returns `true`, if `--remap-path-prefix` was passed on
-    /// the command line, the path as given might not actually be valid.
-    ///
-    /// [`is_real`]: Self::is_real
-    #[unstable(feature = "proc_macro_span", issue = "54725")]
-    pub fn path(&self) -> PathBuf {
-        PathBuf::from(self.0.path())
-    }
-
-    /// Returns `true` if this source file is a real source file, and not generated by an external
-    /// macro's expansion.
-    #[unstable(feature = "proc_macro_span", issue = "54725")]
-    pub fn is_real(&self) -> bool {
-        // This is a hack until intercrate spans are implemented and we can have real source files
-        // for spans generated in external macros.
-        // https://github.com/rust-lang/rust/pull/43604#issuecomment-333334368
-        self.0.is_real()
-    }
-}
-
-#[unstable(feature = "proc_macro_span", issue = "54725")]
-impl fmt::Debug for SourceFile {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("SourceFile")
-            .field("path", &self.path())
-            .field("is_real", &self.is_real())
-            .finish()
-    }
-}
-
-#[unstable(feature = "proc_macro_span", issue = "54725")]
-impl PartialEq for SourceFile {
-    fn eq(&self, other: &Self) -> bool {
-        self.0.eq(&other.0)
-    }
-}
-
-#[unstable(feature = "proc_macro_span", issue = "54725")]
-impl Eq for SourceFile {}
-
 /// A single token or a delimited sequence of token trees (e.g., `[1, (), ..]`).
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
 #[derive(Clone)]

std/src/process.rs

@@ -1286,6 +1286,40 @@ pub struct Output {
     pub stderr: Vec<u8>,
 }
 
+impl Output {
+    /// Returns an error if a nonzero exit status was received.
+    ///
+    /// If the [`Command`] exited successfully,
+    /// `self` is returned.
+    ///
+    /// This is equivalent to calling [`exit_ok`](ExitStatus::exit_ok)
+    /// on [`Output.status`](Output::status).
+    ///
+    /// Note that this will throw away the [`Output::stderr`] field in the error case.
+    /// If the child process outputs useful informantion to stderr, you can:
+    /// * Use `cmd.stderr(Stdio::inherit())` to forward the
+    ///   stderr child process to the parent's stderr,
+    ///   usually printing it to console where the user can see it.
+    ///   This is usually correct for command-line applications.
+    /// * Capture `stderr` using a custom error type.
+    ///   This is usually correct for libraries.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(exit_status_error)]
+    /// # #[cfg(unix)] {
+    /// use std::process::Command;
+    /// assert!(Command::new("false").output().unwrap().exit_ok().is_err());
+    /// # }
+    /// ```
+    #[unstable(feature = "exit_status_error", issue = "84908")]
+    pub fn exit_ok(self) -> Result<Self, ExitStatusError> {
+        self.status.exit_ok()?;
+        Ok(self)
+    }
+}
+
 // If either stderr or stdout are valid utf8 strings it prints the valid
 // strings, otherwise it prints the byte sequence instead
 #[stable(feature = "process_output_debug", since = "1.7.0")]

std/src/sys/pal/unix/mod.rs

@@ -274,6 +274,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         libc::ETXTBSY => ExecutableFileBusy,
         libc::EXDEV => CrossesDevices,
         libc::EINPROGRESS => InProgress,
+        libc::EOPNOTSUPP => Unsupported,
 
         libc::EACCES | libc::EPERM => PermissionDenied,
 

std/src/sys/pal/unix/thread.rs

@@ -8,14 +8,19 @@ use crate::sys::weak::weak;
 use crate::sys::{os, stack_overflow};
 use crate::time::Duration;
 use crate::{cmp, io, ptr};
-#[cfg(not(any(target_os = "l4re", target_os = "vxworks", target_os = "espidf")))]
+#[cfg(not(any(
+    target_os = "l4re",
+    target_os = "vxworks",
+    target_os = "espidf",
+    target_os = "nuttx"
+)))]
 pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024;
 #[cfg(target_os = "l4re")]
 pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024;
 #[cfg(target_os = "vxworks")]
 pub const DEFAULT_MIN_STACK_SIZE: usize = 256 * 1024;
-#[cfg(target_os = "espidf")]
-pub const DEFAULT_MIN_STACK_SIZE: usize = 0; // 0 indicates that the stack size configured in the ESP-IDF menuconfig system should be used
+#[cfg(any(target_os = "espidf", target_os = "nuttx"))]
+pub const DEFAULT_MIN_STACK_SIZE: usize = 0; // 0 indicates that the stack size configured in the ESP-IDF/NuttX menuconfig system should be used
 
 #[cfg(target_os = "fuchsia")]
 mod zircon {
@@ -52,10 +57,10 @@ impl Thread {
         let mut attr: mem::MaybeUninit<libc::pthread_attr_t> = mem::MaybeUninit::uninit();
         assert_eq!(libc::pthread_attr_init(attr.as_mut_ptr()), 0);
 
-        #[cfg(target_os = "espidf")]
+        #[cfg(any(target_os = "espidf", target_os = "nuttx"))]
         if stack > 0 {
             // Only set the stack if a non-zero value is passed
-            // 0 is used as an indication that the default stack size configured in the ESP-IDF menuconfig system should be used
+            // 0 is used as an indication that the default stack size configured in the ESP-IDF/NuttX menuconfig system should be used
             assert_eq!(
                 libc::pthread_attr_setstacksize(
                     attr.as_mut_ptr(),
@@ -65,7 +70,7 @@ impl Thread {
             );
         }
 
-        #[cfg(not(target_os = "espidf"))]
+        #[cfg(not(any(target_os = "espidf", target_os = "nuttx")))]
         {
             let stack_size = cmp::max(stack, min_stack_size(attr.as_ptr()));