Auto merge of rust-lang#123667 - GuillaumeGomez:rollup-yylha9j, r=GuillaumeGomez

Rollup of 6 pull requests

Successful merges:

 - rust-lang#123485 (macOS: Use `libc` definitions for copyfile)
 - rust-lang#123633 (Store all args in the unsupported Command implementation)
 - rust-lang#123638 (rustdoc: synthetic auto: filter out clauses from the implementor's ParamEnv)
 - rust-lang#123653 (Split `non_local_definitions` lint tests in separate test files)
 - rust-lang#123662 (Don't rely on upvars being assigned just because coroutine-closure kind is assigned)
 - rust-lang#123665 (Fix typo in `Future::poll()` docs)

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

Author: bors

compiler/rustc_middle/src/ty/sty.rs

@@ -2231,7 +2231,7 @@ impl<'tcx> Ty<'tcx> {
     pub fn tuple_fields(self) -> &'tcx List<Ty<'tcx>> {
         match self.kind() {
             Tuple(args) => args,
-            _ => bug!("tuple_fields called on non-tuple"),
+            _ => bug!("tuple_fields called on non-tuple: {self:?}"),
         }
     }
 

compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs

@@ -292,7 +292,9 @@ pub(in crate::solve) fn extract_tupled_inputs_and_output_from_callable<'tcx>(
             let kind_ty = args.kind_ty();
             let sig = args.coroutine_closure_sig().skip_binder();
 
-            let coroutine_ty = if let Some(closure_kind) = kind_ty.to_opt_closure_kind() {
+            let coroutine_ty = if let Some(closure_kind) = kind_ty.to_opt_closure_kind()
+                && !args.tupled_upvars_ty().is_ty_var()
+            {
                 if !closure_kind.extends(goal_kind) {
                     return Err(NoSolution);
                 }
@@ -401,7 +403,9 @@ pub(in crate::solve) fn extract_tupled_inputs_and_output_from_async_callable<'tc
             let kind_ty = args.kind_ty();
             let sig = args.coroutine_closure_sig().skip_binder();
             let mut nested = vec![];
-            let coroutine_ty = if let Some(closure_kind) = kind_ty.to_opt_closure_kind() {
+            let coroutine_ty = if let Some(closure_kind) = kind_ty.to_opt_closure_kind()
+                && !args.tupled_upvars_ty().is_ty_var()
+            {
                 if !closure_kind.extends(goal_kind) {
                     return Err(NoSolution);
                 }

compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs

@@ -487,6 +487,11 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
             bug!();
         };
 
+        // Bail if the upvars haven't been constrained.
+        if tupled_upvars_ty.expect_ty().is_ty_var() {
+            return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS);
+        }
+
         let Some(closure_kind) = closure_fn_kind_ty.expect_ty().to_opt_closure_kind() else {
             // We don't need to worry about the self type being an infer var.
             return Err(NoSolution);

compiler/rustc_trait_selection/src/traits/project.rs

@@ -1601,7 +1601,10 @@ fn confirm_closure_candidate<'cx, 'tcx>(
                 // If we know the kind and upvars, use that directly.
                 // Otherwise, defer to `AsyncFnKindHelper::Upvars` to delay
                 // the projection, like the `AsyncFn*` traits do.
-                let output_ty = if let Some(_) = kind_ty.to_opt_closure_kind() {
+                let output_ty = if let Some(_) = kind_ty.to_opt_closure_kind()
+                    // Fall back to projection if upvars aren't constrained
+                    && !args.tupled_upvars_ty().is_ty_var()
+                {
                     sig.to_coroutine_given_kind_and_upvars(
                         tcx,
                         args.parent_args(),
@@ -1731,7 +1734,10 @@ fn confirm_async_closure_candidate<'cx, 'tcx>(
 
             let term = match item_name {
                 sym::CallOnceFuture | sym::CallRefFuture => {
-                    if let Some(closure_kind) = kind_ty.to_opt_closure_kind() {
+                    if let Some(closure_kind) = kind_ty.to_opt_closure_kind()
+                        // Fall back to projection if upvars aren't constrained
+                        && !args.tupled_upvars_ty().is_ty_var()
+                    {
                         if !closure_kind.extends(goal_kind) {
                             bug!("we should not be confirming if the closure kind is not met");
                         }

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -400,39 +400,36 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 }
             }
             ty::CoroutineClosure(def_id, args) => {
+                let args = args.as_coroutine_closure();
                 let is_const = self.tcx().is_const_fn_raw(def_id);
-                match self.infcx.closure_kind(self_ty) {
-                    Some(closure_kind) => {
-                        let no_borrows = match self
-                            .infcx
-                            .shallow_resolve(args.as_coroutine_closure().tupled_upvars_ty())
-                            .kind()
-                        {
-                            ty::Tuple(tys) => tys.is_empty(),
-                            ty::Error(_) => false,
-                            _ => bug!("tuple_fields called on non-tuple"),
-                        };
-                        // A coroutine-closure implements `FnOnce` *always*, since it may
-                        // always be called once. It additionally implements `Fn`/`FnMut`
-                        // only if it has no upvars (therefore no borrows from the closure
-                        // that would need to be represented with a lifetime) and if the
-                        // closure kind permits it.
-                        // FIXME(async_closures): Actually, it could also implement `Fn`/`FnMut`
-                        // if it takes all of its upvars by copy, and none by ref. This would
-                        // require us to record a bit more information during upvar analysis.
-                        if no_borrows && closure_kind.extends(kind) {
-                            candidates.vec.push(ClosureCandidate { is_const });
-                        } else if kind == ty::ClosureKind::FnOnce {
-                            candidates.vec.push(ClosureCandidate { is_const });
-                        }
+                if let Some(closure_kind) = self.infcx.closure_kind(self_ty)
+                    // Ambiguity if upvars haven't been constrained yet
+                    && !args.tupled_upvars_ty().is_ty_var()
+                {
+                    let no_borrows = match args.tupled_upvars_ty().kind() {
+                        ty::Tuple(tys) => tys.is_empty(),
+                        ty::Error(_) => false,
+                        _ => bug!("tuple_fields called on non-tuple"),
+                    };
+                    // A coroutine-closure implements `FnOnce` *always*, since it may
+                    // always be called once. It additionally implements `Fn`/`FnMut`
+                    // only if it has no upvars (therefore no borrows from the closure
+                    // that would need to be represented with a lifetime) and if the
+                    // closure kind permits it.
+                    // FIXME(async_closures): Actually, it could also implement `Fn`/`FnMut`
+                    // if it takes all of its upvars by copy, and none by ref. This would
+                    // require us to record a bit more information during upvar analysis.
+                    if no_borrows && closure_kind.extends(kind) {
+                        candidates.vec.push(ClosureCandidate { is_const });
+                    } else if kind == ty::ClosureKind::FnOnce {
+                        candidates.vec.push(ClosureCandidate { is_const });
                     }
-                    None => {
-                        if kind == ty::ClosureKind::FnOnce {
-                            candidates.vec.push(ClosureCandidate { is_const });
-                        } else {
-                            // This stays ambiguous until kind+upvars are determined.
-                            candidates.ambiguous = true;
-                        }
+                } else {
+                    if kind == ty::ClosureKind::FnOnce {
+                        candidates.vec.push(ClosureCandidate { is_const });
+                    } else {
+                        // This stays ambiguous until kind+upvars are determined.
+                        candidates.ambiguous = true;
                     }
                 }
             }

library/core/src/future/future.rs

@@ -81,7 +81,7 @@ pub trait Future {
     /// An implementation of `poll` should strive to return quickly, and should
     /// not block. Returning quickly prevents unnecessarily clogging up
     /// threads or event loops. If it is known ahead of time that a call to
-    /// `poll` may end up taking awhile, the work should be offloaded to a
+    /// `poll` may end up taking a while, the work should be offloaded to a
     /// thread pool (or something similar) to ensure that `poll` can return
     /// quickly.
     ///

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

@@ -1847,47 +1847,17 @@ pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
 pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
     use crate::sync::atomic::{AtomicBool, Ordering};
 
-    const COPYFILE_ACL: u32 = 1 << 0;
-    const COPYFILE_STAT: u32 = 1 << 1;
-    const COPYFILE_XATTR: u32 = 1 << 2;
-    const COPYFILE_DATA: u32 = 1 << 3;
-
-    const COPYFILE_SECURITY: u32 = COPYFILE_STAT | COPYFILE_ACL;
-    const COPYFILE_METADATA: u32 = COPYFILE_SECURITY | COPYFILE_XATTR;
-    const COPYFILE_ALL: u32 = COPYFILE_METADATA | COPYFILE_DATA;
-
-    const COPYFILE_STATE_COPIED: u32 = 8;
-
-    #[allow(non_camel_case_types)]
-    type copyfile_state_t = *mut libc::c_void;
-    #[allow(non_camel_case_types)]
-    type copyfile_flags_t = u32;
-
-    extern "C" {
-        fn fcopyfile(
-            from: libc::c_int,
-            to: libc::c_int,
-            state: copyfile_state_t,
-            flags: copyfile_flags_t,
-        ) -> libc::c_int;
-        fn copyfile_state_alloc() -> copyfile_state_t;
-        fn copyfile_state_free(state: copyfile_state_t) -> libc::c_int;
-        fn copyfile_state_get(
-            state: copyfile_state_t,
-            flag: u32,
-            dst: *mut libc::c_void,
-        ) -> libc::c_int;
-    }
-
-    struct FreeOnDrop(copyfile_state_t);
+    const COPYFILE_ALL: libc::copyfile_flags_t = libc::COPYFILE_METADATA | libc::COPYFILE_DATA;
+
+    struct FreeOnDrop(libc::copyfile_state_t);
     impl Drop for FreeOnDrop {
         fn drop(&mut self) {
             // The code below ensures that `FreeOnDrop` is never a null pointer
             unsafe {
                 // `copyfile_state_free` returns -1 if the `to` or `from` files
                 // cannot be closed. However, this is not considered this an
                 // error.
-                copyfile_state_free(self.0);
+                libc::copyfile_state_free(self.0);
             }
         }
     }
@@ -1896,6 +1866,7 @@ pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
     // We store the availability in a global to avoid unnecessary syscalls
     static HAS_FCLONEFILEAT: AtomicBool = AtomicBool::new(true);
     syscall! {
+        // Mirrors `libc::fclonefileat`
         fn fclonefileat(
             srcfd: libc::c_int,
             dst_dirfd: libc::c_int,
@@ -1932,22 +1903,22 @@ pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
     // We ensure that `FreeOnDrop` never contains a null pointer so it is
     // always safe to call `copyfile_state_free`
     let state = unsafe {
-        let state = copyfile_state_alloc();
+        let state = libc::copyfile_state_alloc();
         if state.is_null() {
             return Err(crate::io::Error::last_os_error());
         }
         FreeOnDrop(state)
     };
 
-    let flags = if writer_metadata.is_file() { COPYFILE_ALL } else { COPYFILE_DATA };
+    let flags = if writer_metadata.is_file() { COPYFILE_ALL } else { libc::COPYFILE_DATA };
 
-    cvt(unsafe { fcopyfile(reader.as_raw_fd(), writer.as_raw_fd(), state.0, flags) })?;
+    cvt(unsafe { libc::fcopyfile(reader.as_raw_fd(), writer.as_raw_fd(), state.0, flags) })?;
 
     let mut bytes_copied: libc::off_t = 0;
     cvt(unsafe {
-        copyfile_state_get(
+        libc::copyfile_state_get(
             state.0,
-            COPYFILE_STATE_COPIED,
+            libc::COPYFILE_STATE_COPIED as u32,
             core::ptr::addr_of_mut!(bytes_copied) as *mut libc::c_void,
         )
     })?;