diff options
53 files changed, 841 insertions, 242 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index 0117bdd0ba8..416b555db5c 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -21,6 +21,7 @@ use rustc_middle::ty::{GenericArgKind, InternalSubsts}; use rustc_session::parse::feature_err; use rustc_span::symbol::{sym, Ident, Symbol}; use rustc_span::{Span, DUMMY_SP}; +use rustc_target::spec::abi::Abi; use rustc_trait_selection::autoderef::Autoderef; use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt; use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _; @@ -1542,6 +1543,33 @@ fn check_fn_or_method<'tcx>( sig.output(), hir_decl.output.span(), ); + + if sig.abi == Abi::RustCall { + let span = tcx.def_span(def_id); + let has_implicit_self = hir_decl.implicit_self != hir::ImplicitSelfKind::None; + let mut inputs = sig.inputs().iter().skip(if has_implicit_self { 1 } else { 0 }); + // Check that the argument is a tuple + if let Some(ty) = inputs.next() { + wfcx.register_bound( + ObligationCause::new(span, wfcx.body_id, ObligationCauseCode::RustCall), + wfcx.param_env, + *ty, + tcx.require_lang_item(hir::LangItem::Tuple, Some(span)), + ); + } else { + tcx.sess.span_err( + hir_decl.inputs.last().map_or(span, |input| input.span), + "functions with the \"rust-call\" ABI must take a single non-self tuple argument", + ); + } + // No more inputs other than the `self` type and the tuple type + if inputs.next().is_some() { + tcx.sess.span_err( + hir_decl.inputs.last().map_or(span, |input| input.span), + "functions with the \"rust-call\" ABI must take a single non-self tuple argument", + ); + } + } } /// Basically `check_associated_type_bounds`, but separated for now and should be diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs index 000f4c9b684..2b019c8c9b7 100644 --- a/compiler/rustc_hir_typeck/src/callee.rs +++ b/compiler/rustc_hir_typeck/src/callee.rs @@ -468,6 +468,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { def_id, ); + if fn_sig.abi == abi::Abi::RustCall { + let sp = arg_exprs.last().map_or(call_expr.span, |expr| expr.span); + if let Some(ty) = fn_sig.inputs().last().copied() { + self.register_bound( + ty, + self.tcx.require_lang_item(hir::LangItem::Tuple, Some(sp)), + traits::ObligationCause::new(sp, self.body_id, traits::RustCall), + ); + } else { + self.tcx.sess.span_err( + sp, + "functions with the \"rust-call\" ABI must take a single non-self tuple argument", + ); + } + } + fn_sig.output() } diff --git a/compiler/rustc_hir_typeck/src/check.rs b/compiler/rustc_hir_typeck/src/check.rs index 80147d90091..37af6e79c3e 100644 --- a/compiler/rustc_hir_typeck/src/check.rs +++ b/compiler/rustc_hir_typeck/src/check.rs @@ -6,13 +6,11 @@ use rustc_hir as hir; use rustc_hir::def::DefKind; use rustc_hir::intravisit::Visitor; use rustc_hir::lang_items::LangItem; -use rustc_hir::{ImplicitSelfKind, ItemKind, Node}; use rustc_hir_analysis::check::fn_maybe_err; use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_infer::infer::RegionVariableOrigin; use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_span::def_id::LocalDefId; -use rustc_target::spec::abi::Abi; use rustc_trait_selection::traits; use std::cell::RefCell; @@ -56,41 +54,6 @@ pub(super) fn check_fn<'a, 'tcx>( fn_maybe_err(tcx, span, fn_sig.abi); - if fn_sig.abi == Abi::RustCall { - let expected_args = if let ImplicitSelfKind::None = decl.implicit_self { 1 } else { 2 }; - - let err = || { - let item = match tcx.hir().get(fn_id) { - Node::Item(hir::Item { kind: ItemKind::Fn(header, ..), .. }) => Some(header), - Node::ImplItem(hir::ImplItem { - kind: hir::ImplItemKind::Fn(header, ..), .. - }) => Some(header), - Node::TraitItem(hir::TraitItem { - kind: hir::TraitItemKind::Fn(header, ..), - .. - }) => Some(header), - // Closures are RustCall, but they tuple their arguments, so shouldn't be checked - Node::Expr(hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => None, - node => bug!("Item being checked wasn't a function/closure: {:?}", node), - }; - - if let Some(header) = item { - tcx.sess.span_err(header.span, "functions with the \"rust-call\" ABI must take a single non-self argument that is a tuple"); - } - }; - - if fn_sig.inputs().len() != expected_args { - err() - } else { - // FIXME(CraftSpider) Add a check on parameter expansion, so we don't just make the ICE happen later on - // This will probably require wide-scale changes to support a TupleKind obligation - // We can't resolve this without knowing the type of the param - if !matches!(fn_sig.inputs()[expected_args - 1].kind(), ty::Tuple(_) | ty::Param(_)) { - err() - } - } - } - if body.generator_kind.is_some() && can_be_generator.is_some() { let yield_ty = fcx .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::TypeInference, span }); diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs index e1955d838f2..4066cca8a4b 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs @@ -136,6 +136,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { tuple_arguments, Some(method.def_id), ); + method.sig.output() } @@ -214,7 +215,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { "cannot use call notation; the first type parameter \ for the function trait is neither a tuple nor unit" ) - .emit(); + .delay_as_bug(); (self.err_args(provided_args.len()), None) } } diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs index d1762598a52..624443d9594 100644 --- a/compiler/rustc_hir_typeck/src/lib.rs +++ b/compiler/rustc_hir_typeck/src/lib.rs @@ -458,7 +458,7 @@ fn report_unexpected_variant_res(tcx: TyCtxt<'_>, res: Res, qpath: &hir::QPath<' /// # fn f(x: (isize, isize)) {} /// f((1, 2)); /// ``` -#[derive(Clone, Eq, PartialEq)] +#[derive(Copy, Clone, Eq, PartialEq)] enum TupleArgumentsFlag { DontTupleArguments, TupleArguments, diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs index 07ee758b32c..a29f0722ff7 100644 --- a/compiler/rustc_middle/src/traits/mod.rs +++ b/compiler/rustc_middle/src/traits/mod.rs @@ -438,6 +438,8 @@ pub enum ObligationCauseCode<'tcx> { }, AscribeUserTypeProvePredicate(Span), + + RustCall, } /// The 'location' at which we try to perform HIR-based wf checking. diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index dacce5cd2f6..54281f91205 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -700,6 +700,25 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } } + if Some(trait_ref.def_id()) == tcx.lang_items().tuple_trait() { + match obligation.cause.code().peel_derives() { + ObligationCauseCode::RustCall => { + err.set_primary_message("functions with the \"rust-call\" ABI must take a single non-self tuple argument"); + } + ObligationCauseCode::BindingObligation(def_id, _) + | ObligationCauseCode::ItemObligation(def_id) + if ty::ClosureKind::from_def_id(tcx, *def_id).is_some() => + { + err.code(rustc_errors::error_code!(E0059)); + err.set_primary_message(format!( + "type parameter to bare `{}` trait must be a tuple", + tcx.def_path_str(*def_id) + )); + } + _ => {} + } + } + if Some(trait_ref.def_id()) == tcx.lang_items().drop_trait() && predicate_is_const { @@ -848,12 +867,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { ); } - let is_fn_trait = [ - self.tcx.lang_items().fn_trait(), - self.tcx.lang_items().fn_mut_trait(), - self.tcx.lang_items().fn_once_trait(), - ] - .contains(&Some(trait_ref.def_id())); + let is_fn_trait = + ty::ClosureKind::from_def_id(tcx, trait_ref.def_id()).is_some(); let is_target_feature_fn = if let ty::FnDef(def_id, _) = *trait_ref.skip_binder().self_ty().kind() { diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index d7606d88803..0f4aa87b43f 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -2407,7 +2407,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { | ObligationCauseCode::CheckAssociatedTypeBounds { .. } | ObligationCauseCode::LetElse | ObligationCauseCode::BinOp { .. } - | ObligationCauseCode::AscribeUserTypeProvePredicate(..) => {} + | ObligationCauseCode::AscribeUserTypeProvePredicate(..) + | ObligationCauseCode::RustCall => {} ObligationCauseCode::SliceOrArrayElem => { err.note("slice and array elements must have `Sized` type"); } diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs index b7e7d5a38a5..66f4c19e0f9 100644 --- a/library/alloc/src/boxed.rs +++ b/library/alloc/src/boxed.rs @@ -158,6 +158,8 @@ use core::hash::{Hash, Hasher}; #[cfg(not(no_global_oom_handling))] use core::iter::FromIterator; use core::iter::{FusedIterator, Iterator}; +#[cfg(not(bootstrap))] +use core::marker::Tuple; use core::marker::{Destruct, Unpin, Unsize}; use core::mem; use core::ops::{ @@ -1979,6 +1981,7 @@ impl<I: ExactSizeIterator + ?Sized, A: Allocator> ExactSizeIterator for Box<I, A #[stable(feature = "fused", since = "1.26.0")] impl<I: FusedIterator + ?Sized, A: Allocator> FusedIterator for Box<I, A> {} +#[cfg(bootstrap)] #[stable(feature = "boxed_closure_impls", since = "1.35.0")] impl<Args, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> { type Output = <F as FnOnce<Args>>::Output; @@ -1988,6 +1991,17 @@ impl<Args, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> { } } +#[cfg(not(bootstrap))] +#[stable(feature = "boxed_closure_impls", since = "1.35.0")] +impl<Args: Tuple, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> { + type Output = <F as FnOnce<Args>>::Output; + + extern "rust-call" fn call_once(self, args: Args) -> Self::Output { + <F as FnOnce<Args>>::call_once(*self, args) + } +} + +#[cfg(bootstrap)] #[stable(feature = "boxed_closure_impls", since = "1.35.0")] impl<Args, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> { extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output { @@ -1995,6 +2009,15 @@ impl<Args, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> { } } +#[cfg(not(bootstrap))] +#[stable(feature = "boxed_closure_impls", since = "1.35.0")] +impl<Args: Tuple, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> { + extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output { + <F as FnMut<Args>>::call_mut(self, args) + } +} + +#[cfg(bootstrap)] #[stable(feature = "boxed_closure_impls", since = "1.35.0")] impl<Args, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> { extern "rust-call" fn call(&self, args: Args) -> Self::Output { @@ -2002,6 +2025,14 @@ impl<Args, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> { } } +#[cfg(not(bootstrap))] +#[stable(feature = "boxed_closure_impls", since = "1.35.0")] +impl<Args: Tuple, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> { + extern "rust-call" fn call(&self, args: Args) -> Self::Output { + <F as Fn<Args>>::call(self, args) + } +} + #[unstable(feature = "coerce_unsized", issue = "27732")] impl<T: ?Sized + Unsize<U>, U: ?Sized, A: Allocator> CoerceUnsized<Box<U, A>> for Box<T, A> {} diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs index ce36b116f13..008926666c1 100644 --- a/library/alloc/src/lib.rs +++ b/library/alloc/src/lib.rs @@ -150,6 +150,7 @@ #![feature(trusted_len)] #![feature(trusted_random_access)] #![feature(try_trait_v2)] +#![cfg_attr(not(bootstrap), feature(tuple_trait))] #![feature(unchecked_math)] #![feature(unicode_internals)] #![feature(unsize)] diff --git a/library/core/src/const_closure.rs b/library/core/src/const_closure.rs index 9e9c02093be..151c8e6d898 100644 --- a/library/core/src/const_closure.rs +++ b/library/core/src/const_closure.rs @@ -1,4 +1,6 @@ use crate::marker::Destruct; +#[cfg(not(bootstrap))] +use crate::marker::Tuple; /// Struct representing a closure with mutably borrowed data. /// @@ -44,6 +46,7 @@ impl<'a, CapturedData: ?Sized, Function> ConstFnMutClosure<&'a mut CapturedData, macro_rules! impl_fn_mut_tuple { ($($var:ident)*) => { + #[cfg(bootstrap)] #[allow(unused_parens)] impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> @@ -56,6 +59,7 @@ macro_rules! impl_fn_mut_tuple { self.call_mut(args) } } + #[cfg(bootstrap)] #[allow(unused_parens)] impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> @@ -68,6 +72,32 @@ macro_rules! impl_fn_mut_tuple { (self.func)(($($var),*), args) } } + #[cfg(not(bootstrap))] + #[allow(unused_parens)] + impl<'a, $($var,)* ClosureArguments: Tuple, Function, ClosureReturnValue> const + FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> + where + Function: ~const Fn(($(&mut $var),*), ClosureArguments) -> ClosureReturnValue+ ~const Destruct, + { + type Output = ClosureReturnValue; + + extern "rust-call" fn call_once(mut self, args: ClosureArguments) -> Self::Output { + self.call_mut(args) + } + } + #[cfg(not(bootstrap))] + #[allow(unused_parens)] + impl<'a, $($var,)* ClosureArguments: Tuple, Function, ClosureReturnValue> const + FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function> + where + Function: ~const Fn(($(&mut $var),*), ClosureArguments)-> ClosureReturnValue, + { + extern "rust-call" fn call_mut(&mut self, args: ClosureArguments) -> Self::Output { + #[allow(non_snake_case)] + let ($($var),*) = &mut self.data; + (self.func)(($($var),*), args) + } + } }; } impl_fn_mut_tuple!(A); diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index 1dc79afe83f..bfbd4301230 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -55,6 +55,8 @@ #![allow(missing_docs)] use crate::marker::DiscriminantKind; +#[cfg(not(bootstrap))] +use crate::marker::Tuple; use crate::mem; // These imports are used for simplifying intra-doc links @@ -2169,11 +2171,75 @@ extern "rust-intrinsic" { /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*, /// which violates the principle that a `const fn` must behave the same at /// compile-time and at run-time. The unsafe code in crate B is fine. + #[cfg(bootstrap)] #[rustc_const_unstable(feature = "const_eval_select", issue = "none")] pub fn const_eval_select<ARG, F, G, RET>(arg: ARG, called_in_const: F, called_at_rt: G) -> RET where G: FnOnce<ARG, Output = RET>, F: FnOnce<ARG, Output = RET>; + + /// Selects which function to call depending on the context. + /// + /// If this function is evaluated at compile-time, then a call to this + /// intrinsic will be replaced with a call to `called_in_const`. It gets + /// replaced with a call to `called_at_rt` otherwise. + /// + /// # Type Requirements + /// + /// The two functions must be both function items. They cannot be function + /// pointers or closures. The first function must be a `const fn`. + /// + /// `arg` will be the tupled arguments that will be passed to either one of + /// the two functions, therefore, both functions must accept the same type of + /// arguments. Both functions must return RET. + /// + /// # Safety + /// + /// The two functions must behave observably equivalent. Safe code in other + /// crates may assume that calling a `const fn` at compile-time and at run-time + /// produces the same result. A function that produces a different result when + /// evaluated at run-time, or has any other observable side-effects, is + /// *unsound*. + /// + /// Here is an example of how this could cause a problem: + /// ```no_run + /// #![feature(const_eval_select)] + /// #![feature(core_intrinsics)] + /// use std::hint::unreachable_unchecked; + /// use std::intrinsics::const_eval_select; + /// + /// // Crate A + /// pub const fn inconsistent() -> i32 { + /// fn runtime() -> i32 { 1 } + /// const fn compiletime() -> i32 { 2 } + /// + /// unsafe { + // // ⚠ This code violates the required equivalence of `compiletime` + /// // and `runtime`. + /// const_eval_select((), compiletime, runtime) + /// } + /// } + /// + /// // Crate B + /// const X: i32 = inconsistent(); + /// let x = inconsistent(); + /// if x != X { unsafe { unreachable_unchecked(); }} + /// ``` + /// + /// This code causes Undefined Behavior when being run, since the + /// `unreachable_unchecked` is actually being reached. The bug is in *crate A*, + /// which violates the principle that a `const fn` must behave the same at + /// compile-time and at run-time. The unsafe code in crate B is fine. + #[cfg(not(bootstrap))] + #[rustc_const_unstable(feature = "const_eval_select", issue = "none")] + pub fn const_eval_select<ARG: Tuple, F, G, RET>( + arg: ARG, + called_in_const: F, + called_at_rt: G, + ) -> RET + where + G: FnOnce<ARG, Output = RET>, + F: FnOnce<ARG, Output = RET>; } // Some functions are defined here because they accidentally got made diff --git a/library/core/src/ops/function.rs b/library/core/src/ops/function.rs index 2e0a752c815..8d4b0a7ccac 100644 --- a/library/core/src/ops/function.rs +++ b/library/core/src/ops/function.rs @@ -1,3 +1,6 @@ +#[cfg(not(bootstrap))] +use crate::marker::Tuple; + /// The version of the call operator that takes an immutable receiver. /// /// Instances of `Fn` can be called repeatedly without mutating state. @@ -51,6 +54,7 @@ /// let double = |x| x * 2; /// assert_eq!(call_with_one(double), 2); /// ``` +#[cfg(bootstrap)] #[lang = "fn"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "Fn"] @@ -71,13 +75,93 @@ )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] -#[cfg_attr(not(bootstrap), const_trait)] pub trait Fn<Args>: FnMut<Args> { /// Performs the call operation. #[unstable(feature = "fn_traits", issue = "29625")] extern "rust-call" fn call(&self, args: Args) -> Self::Output; } +/// The version of the call operator that takes an immutable receiver. +/// +/// Instances of `Fn` can be called repeatedly without mutating state. +/// +/// *This trait (`Fn`) is not to be confused with [function pointers] +/// (`fn`).* +/// +/// `Fn` is implemented automatically by closures which only take immutable +/// references to captured variables or don't capture anything at all, as well +/// as (safe) [function pointers] (with some caveats, see their documentation +/// for more details). Additionally, for any type `F` that implements `Fn`, `&F` +/// implements `Fn`, too. +/// +/// Since both [`FnMut`] and [`FnOnce`] are supertraits of `Fn`, any +/// instance of `Fn` can be used as a parameter where a [`FnMut`] or [`FnOnce`] +/// is expected. +/// +/// Use `Fn` as a bound when you want to accept a parameter of function-like +/// type and need to call it repeatedly and without mutating state (e.g., when +/// calling it concurrently). If you do not need such strict requirements, use +/// [`FnMut`] or [`FnOnce`] as bounds. +/// +/// See the [chapter on closures in *The Rust Programming Language*][book] for +/// some more information on this topic. +/// +/// Also of note is the special syntax for `Fn` traits (e.g. +/// `Fn(usize, bool) -> usize`). Those interested in the technical details of +/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. +/// +/// [book]: ../../book/ch13-01-closures.html +/// [function pointers]: fn +/// [nomicon]: ../../nomicon/hrtb.html +/// +/// # Examples +/// +/// ## Calling a closure +/// +/// ``` +/// let square = |x| x * x; +/// assert_eq!(square(5), 25); +/// ``` +/// +/// ## Using a `Fn` parameter +/// +/// ``` +/// fn call_with_one<F>(func: F) -> usize +/// where F: Fn(usize) -> usize { +/// func(1) +/// } +/// +/// let double = |x| x * 2; +/// assert_eq!(call_with_one(double), 2); +/// ``` +#[cfg(not(bootstrap))] +#[lang = "fn"] +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_diagnostic_item = "Fn"] +#[rustc_paren_sugar] +#[rustc_on_unimplemented( + on( + Args = "()", + note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" + ), + on( + _Self = "unsafe fn", + note = "unsafe function cannot be called generically without an unsafe block", + // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string + label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" + ), + message = "expected a `{Fn}<{Args}>` closure, found `{Self}`", + label = "expected an `Fn<{Args}>` closure, found `{Self}`" +)] +#[fundamental] // so that regex can rely that `&str: !FnMut` +#[must_use = "closures are lazy and do nothing unless called"] +#[const_trait] +pub trait Fn<Args: Tuple>: FnMut<Args> { + /// Performs the call operation. + #[unstable(feature = "fn_traits", issue = "29625")] + extern "rust-call" fn call(&self, args: Args) -> Self::Output; +} + /// The version of the call operator that takes a mutable receiver. /// /// Instances of `FnMut` can be called repeatedly and may mutate state. @@ -139,6 +223,7 @@ pub trait Fn<Args>: FnMut<Args> { /// /// assert_eq!(x, 5); /// ``` +#[cfg(bootstrap)] #[lang = "fn_mut"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "FnMut"] @@ -159,13 +244,101 @@ pub trait Fn<Args>: FnMut<Args> { )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] -#[cfg_attr(not(bootstrap), const_trait)] pub trait FnMut<Args>: FnOnce<Args> { /// Performs the call operation. #[unstable(feature = "fn_traits", issue = "29625")] extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output; } +/// The version of the call operator that takes a mutable receiver. +/// +/// Instances of `FnMut` can be called repeatedly and may mutate state. +/// +/// `FnMut` is implemented automatically by closures which take mutable +/// references to captured variables, as well as all types that implement +/// [`Fn`], e.g., (safe) [function pointers] (since `FnMut` is a supertrait of +/// [`Fn`]). Additionally, for any type `F` that implements `FnMut`, `&mut F` +/// implements `FnMut`, too. +/// +/// Since [`FnOnce`] is a supertrait of `FnMut`, any instance of `FnMut` can be +/// used where a [`FnOnce`] is expected, and since [`Fn`] is a subtrait of +/// `FnMut`, any instance of [`Fn`] can be used where `FnMut` is expected. +/// +/// Use `FnMut` as a bound when you want to accept a parameter of function-like +/// type and need to call it repeatedly, while allowing it to mutate state. +/// If you don't want the parameter to mutate state, use [`Fn`] as a +/// bound; if you don't need to call it repeatedly, use [`FnOnce`]. +/// +/// See the [chapter on closures in *The Rust Programming Language*][book] for +/// some more information on this topic. +/// +/// Also of note is the special syntax for `Fn` traits (e.g. +/// `Fn(usize, bool) -> usize`). Those interested in the technical details of +/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. +/// +/// [book]: ../../book/ch13-01-closures.html +/// [function pointers]: fn +/// [nomicon]: ../../nomicon/hrtb.html +/// +/// # Examples +/// +/// ## Calling a mutably capturing closure +/// +/// ``` +/// let mut x = 5; +/// { +/// let mut square_x = || x *= x; +/// square_x(); +/// } +/// assert_eq!(x, 25); +/// ``` +/// +/// ## Using a `FnMut` parameter +/// +/// ``` +/// fn do_twice<F>(mut func: F) +/// where F: FnMut() +/// { +/// func(); +/// func(); +/// } +/// +/// let mut x: usize = 1; +/// { +/// let add_two_to_x = || x += 2; +/// do_twice(add_two_to_x); +/// } +/// +/// assert_eq!(x, 5); +/// ``` +#[cfg(not(bootstrap))] +#[lang = "fn_mut"] +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_diagnostic_item = "FnMut"] +#[rustc_paren_sugar] +#[rustc_on_unimplemented( + on( + Args = "()", + note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" + ), + on( + _Self = "unsafe fn", + note = "unsafe function cannot be called generically without an unsafe block", + // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string + label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" + ), + message = "expected a `{FnMut}<{Args}>` closure, found `{Self}`", + label = "expected an `FnMut<{Args}>` closure, found `{Self}`" +)] +#[fundamental] // so that regex can rely that `&str: !FnMut` +#[must_use = "closures are lazy and do nothing unless called"] +#[const_trait] +pub trait FnMut<Args: Tuple>: FnOnce<Args> { + /// Performs the call operation. + #[unstable(feature = "fn_traits", issue = "29625")] + extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output; +} + /// The version of the call operator that takes a by-value receiver. /// /// Instances of `FnOnce` can be called, but might not be callable multiple @@ -219,6 +392,7 @@ pub trait FnMut<Args>: FnOnce<Args> { /// /// // `consume_and_return_x` can no longer be invoked at this point /// ``` +#[cfg(bootstrap)] #[lang = "fn_once"] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_diagnostic_item = "FnOnce"] @@ -239,7 +413,6 @@ pub trait FnMut<Args>: FnOnce<Args> { )] #[fundamental] // so that regex can rely that `&str: !FnMut` #[must_use = "closures are lazy and do nothing unless called"] -#[cfg_attr(not(bootstrap), const_trait)] pub trait FnOnce<Args> { /// The returned type after the call operator is used. #[lang = "fn_once_output"] @@ -251,6 +424,93 @@ pub trait FnOnce<Args> { extern "rust-call" fn call_once(self, args: Args) -> Self::Output; } +/// The version of the call operator that takes a by-value receiver. +/// +/// Instances of `FnOnce` can be called, but might not be callable multiple +/// times. Because of this, if the only thing known about a type is that it +/// implements `FnOnce`, it can only be called once. +/// +/// `FnOnce` is implemented automatically by closures that might consume captured +/// variables, as well as all types that implement [`FnMut`], e.g., (safe) +/// [function pointers] (since `FnOnce` is a supertrait of [`FnMut`]). +/// +/// Since both [`Fn`] and [`FnMut`] are subtraits of `FnOnce`, any instance of +/// [`Fn`] or [`FnMut`] can be used where a `FnOnce` is expected. +/// +/// Use `FnOnce` as a bound when you want to accept a parameter of function-like +/// type and only need to call it once. If you need to call the parameter +/// repeatedly, use [`FnMut`] as a bound; if you also need it to not mutate +/// state, use [`Fn`]. +/// +/// See the [chapter on closures in *The Rust Programming Language*][book] for +/// some more information on this topic. +/// +/// Also of note is the special syntax for `Fn` traits (e.g. +/// `Fn(usize, bool) -> usize`). Those interested in the technical details of +/// this can refer to [the relevant section in the *Rustonomicon*][nomicon]. +/// +/// [book]: ../../book/ch13-01-closures.html +/// [function pointers]: fn +/// [nomicon]: ../../nomicon/hrtb.html +/// +/// # Examples +/// +/// ## Using a `FnOnce` parameter +/// +/// ``` +/// fn consume_with_relish<F>(func: F) +/// where F: FnOnce() -> String +/// { +/// // `func` consumes its captured variables, so it cannot be run more +/// // than once. +/// println!("Consumed: {}", func()); +/// +/// println!("Delicious!"); +/// +/// // Attempting to invoke `func()` again will throw a `use of moved +/// // value` error for `func`. +/// } +/// +/// let x = String::from("x"); +/// let consume_and_return_x = move || x; +/// consume_with_relish(consume_and_return_x); +/// +/// // `consume_and_return_x` can no longer be invoked at this point +/// ``` +#[cfg(not(bootstrap))] +#[lang = "fn_once"] +#[stable(feature = "rust1", since = "1.0.0")] +#[rustc_diagnostic_item = "FnOnce"] +#[rustc_paren_sugar] +#[rustc_on_unimplemented( + on( + Args = "()", + note = "wrap the `{Self}` in a closure with no arguments: `|| {{ /* code */ }}`" + ), + on( + _Self = "unsafe fn", + note = "unsafe function cannot be called generically without an unsafe block", + // SAFETY: tidy is not smart enough to tell that the below unsafe block is a string + label = "call the function in a closure: `|| unsafe {{ /* code */ }}`" + ), + message = "expected a `{FnOnce}<{Args}>` closure, found `{Self}`", + label = "expected an `FnOnce<{Args}>` closure, found `{Self}`" +)] +#[fundamental] // so that regex can rely that `&str: !FnMut` +#[must_use = "closures are lazy and do nothing unless called"] +#[const_trait] +pub trait FnOnce<Args: Tuple> { + /// The returned type after the call operator is used. + #[lang = "fn_once_output"] + #[stable(feature = "fn_once_output", since = "1.12.0")] + type Output; + + /// Performs the call operation. + #[unstable(feature = "fn_traits", issue = "29625")] + extern "rust-call" fn call_once(self, args: Args) -> Self::Output; +} + +#[cfg(bootstrap)] mod impls { #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_unstable(feature = "const_fn_trait_ref_impls", issue = "101803")] @@ -310,3 +570,61 @@ mod impls { } } } + +#[cfg(not(bootstrap))] +mod impls { + use crate::marker::Tuple; + + #[stable(feature = "rust1", since = "1.0.0")] + impl<A: Tuple, F: ?Sized> Fn<A> for &F + where + F: Fn<A>, + { + extern "rust-call" fn call(&self, args: A) -> F::Output { + (**self).call(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + impl<A: Tuple, F: ?Sized> FnMut<A> for &F + where + F: Fn<A>, + { + extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { + (**self).call(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + impl<A: Tuple, F: ?Sized> FnOnce<A> for &F + where + F: Fn<A>, + { + type Output = F::Output; + + extern "rust-call" fn call_once(self, args: A) -> F::Output { + (*self).call(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + impl<A: Tuple, F: ?Sized> FnMut<A> for &mut F + where + F: FnMut<A>, + { + extern "rust-call" fn call_mut(&mut self, args: A) -> F::Output { + (*self).call_mut(args) + } + } + + #[stable(feature = "rust1", since = "1.0.0")] + impl<A: Tuple, F: ?Sized> FnOnce<A> for &mut F + where + F: FnMut<A>, + { + type Output = F::Output; + extern "rust-call" fn call_once(self, args: A) -> F::Output { + (*self).call_mut(args) + } + } +} diff --git a/src/test/codegen/avr/avr-func-addrspace.rs b/src/test/codegen/avr/avr-func-addrspace.rs index a038dfe76f7..cbbcfad3ef4 100644 --- a/src/test/codegen/avr/avr-func-addrspace.rs +++ b/src/test/codegen/avr/avr-func-addrspace.rs @@ -19,6 +19,8 @@ pub trait Sized { } pub trait Copy { } #[lang = "receiver"] pub trait Receiver { } +#[lang = "tuple_trait"] +pub trait Tuple { } pub struct Result<T, E> { _a: T, _b: E } @@ -29,7 +31,7 @@ impl Copy for &usize {} pub unsafe fn drop_in_place<T: ?Sized>(_: *mut T) {} #[lang = "fn_once"] -pub trait FnOnce<Args> { +pub trait FnOnce<Args: Tuple> { #[lang = "fn_once_output"] type Output; @@ -37,24 +39,16 @@ pub trait FnOnce<Args> { } #[lang = "fn_mut"] -pub trait FnMut<Args> : FnOnce<Args> { +pub trait FnMut<Args: Tuple> : FnOnce<Args> { extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output; } #[lang = "fn"] -pub trait Fn<Args>: FnOnce<Args> { +pub trait Fn<Args: Tuple>: FnOnce<Args> { /// Performs the call operation. extern "rust-call" fn call(&self, args: Args) -> Self::Output; } -impl<'a, A, R> FnOnce<A> for &'a fn(A) -> R { - type Output = R; - - extern "rust-call" fn call_once(self, args: A) -> R { - (*self)(args) - } -} - pub static mut STORAGE_FOO: fn(&usize, &mut u32) -> Result<(), ()> = arbitrary_black_box; pub static mut STORAGE_BAR: u32 = 12; diff --git a/src/test/incremental/hashes/extern_mods.rs b/src/test/incremental/hashes/extern_mods.rs index ff79acc7f63..3121abbea36 100644 --- a/src/test/incremental/hashes/extern_mods.rs +++ b/src/test/incremental/hashes/extern_mods.rs @@ -128,7 +128,7 @@ extern "C" { // Change calling convention --------------------------------------------------- #[cfg(any(cfail1,cfail4))] extern "C" { - pub fn change_calling_convention(c: i32); + pub fn change_calling_convention(c: (i32,)); } #[cfg(not(any(cfail1,cfail4)))] @@ -137,7 +137,7 @@ extern "C" { #[rustc_clean(cfg = "cfail5", except = "hir_owner,hir_owner_nodes")] #[rustc_clean(cfg = "cfail6")] extern "rust-call" { - pub fn change_calling_convention(c: i32); + pub fn change_calling_convention(c: (i32,)); } // Make function public -------------------------------------------------------- diff --git a/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call.rs b/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call.rs index 7f365ce2bba..ece4dea9aaf 100644 --- a/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call.rs +++ b/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call.rs @@ -1,7 +1,8 @@ #![feature(unsized_locals)] #![feature(unboxed_closures)] +#![feature(tuple_trait)] -pub trait FnOnce<Args> { +pub trait FnOnce<Args: std::marker::Tuple> { type Output; extern "rust-call" fn call_once(self, args: Args) -> Self::Output; } diff --git a/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call2.rs b/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call2.rs index a78b897d194..94df2b0b83f 100644 --- a/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call2.rs +++ b/src/test/run-pass-valgrind/unsized-locals/by-value-trait-objects-rust-call2.rs @@ -1,7 +1,8 @@ #![feature(unsized_locals)] #![feature(unboxed_closures)] +#![feature(tuple_trait)] -pub trait FnOnce<Args> { +pub trait FnOnce<Args: std::marker::Tuple> { type Output; extern "rust-call" fn call_once(self, args: Args) -> Self::Output; } diff --git a/src/test/ui/abi/issues/issue-22565-rust-call.rs b/src/test/ui/abi/issues/issue-22565-rust-call.rs index a08e0bfb5e5..a572666c888 100644 --- a/src/test/ui/abi/issues/issue-22565-rust-call.rs +++ b/src/test/ui/abi/issues/issue-22565-rust-call.rs @@ -1,32 +1,31 @@ #![feature(unboxed_closures)] extern "rust-call" fn b(_i: i32) {} -//~^ ERROR functions with the "rust-call" ABI must take a single non-self argument that is a tuple +//~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument trait Tr { extern "rust-call" fn a(); + //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument extern "rust-call" fn b() {} - //~^ ERROR functions with the "rust-call" ABI must take a single non-self argument + //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument } struct Foo; impl Foo { extern "rust-call" fn bar() {} - //~^ ERROR functions with the "rust-call" ABI must take a single non-self argument + //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument } impl Tr for Foo { extern "rust-call" fn a() {} - //~^ ERROR functions with the "rust-call" ABI must take a single non-self argument + //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument } -fn main () { +fn main() { b(10); - Foo::bar(); - <Foo as Tr>::a(); <Foo as Tr>::b(); } diff --git a/src/test/ui/abi/issues/issue-22565-rust-call.stderr b/src/test/ui/abi/issues/issue-22565-rust-call.stderr index 3eee10bc5e9..9d205b444fa 100644 --- a/src/test/ui/abi/issues/issue-22565-rust-call.stderr +++ b/src/test/ui/abi/issues/issue-22565-rust-call.stderr @@ -1,26 +1,33 @@ -error: functions with the "rust-call" ABI must take a single non-self argument that is a tuple +error[E0277]: functions with the "rust-call" ABI must take a single non-self tuple argument --> $DIR/issue-22565-rust-call.rs:3:1 | LL | extern "rust-call" fn b(_i: i32) {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Tuple` is not implemented for `i32` -error: functions with the "rust-call" ABI must take a single non-self argument that is a tuple - --> $DIR/issue-22565-rust-call.rs:9:5 - | -LL | extern "rust-call" fn b() {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^ - -error: functions with the "rust-call" ABI must take a single non-self argument that is a tuple - --> $DIR/issue-22565-rust-call.rs:16:5 +error: functions with the "rust-call" ABI must take a single non-self tuple argument + --> $DIR/issue-22565-rust-call.rs:17:5 | LL | extern "rust-call" fn bar() {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: functions with the "rust-call" ABI must take a single non-self argument that is a tuple - --> $DIR/issue-22565-rust-call.rs:21:5 +error: functions with the "rust-call" ABI must take a single non-self tuple argument + --> $DIR/issue-22565-rust-call.rs:22:5 | LL | extern "rust-call" fn a() {} | ^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 4 previous errors +error: functions with the "rust-call" ABI must take a single non-self tuple argument + --> $DIR/issue-22565-rust-call.rs:7:5 + | +LL | extern "rust-call" fn a(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: functions with the "rust-call" ABI must take a single non-self tuple argument + --> $DIR/issue-22565-rust-call.rs:10:5 + | +LL | extern "rust-call" fn b() {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 5 previous errors +For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/abi/rustcall-generic.rs b/src/test/ui/abi/rustcall-generic.rs index 411c98e1031..6eaccc436b6 100644 --- a/src/test/ui/abi/rustcall-generic.rs +++ b/src/test/ui/abi/rustcall-generic.rs @@ -2,9 +2,9 @@ // check-pass //[opt] compile-flags: -Zmir-opt-level=3 -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] -extern "rust-call" fn foo<T>(_: T) {} +extern "rust-call" fn foo<T: std::marker::Tuple>(_: T) {} fn main() { foo(()); diff --git a/src/test/ui/borrowck/borrow-immutable-upvar-mutation.rs b/src/test/ui/borrowck/borrow-immutable-upvar-mutation.rs index e2f016614bf..a3350024e75 100644 --- a/src/test/ui/borrowck/borrow-immutable-upvar-mutation.rs +++ b/src/test/ui/borrowck/borrow-immutable-upvar-mutation.rs @@ -1,4 +1,4 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] // Tests that we can't assign to or mutably borrow upvars from `Fn` // closures (issue #17780) @@ -7,10 +7,10 @@ fn set(x: &mut usize) { *x = 5; } -fn to_fn<A, F: Fn<A>>(f: F) -> F { +fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { f } -fn to_fn_mut<A, F: FnMut<A>>(f: F) -> F { +fn to_fn_mut<A: std::marker::Tuple, F: FnMut<A>>(f: F) -> F { f } diff --git a/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr b/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr index 093589ed092..a0eaf1f163b 100644 --- a/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr +++ b/src/test/ui/borrowck/borrow-immutable-upvar-mutation.stderr @@ -1,8 +1,8 @@ error[E0594]: cannot assign to `x`, as it is a captured variable in a `Fn` closure --> $DIR/borrow-immutable-upvar-mutation.rs:21:27 | -LL | fn to_fn<A, F: Fn<A>>(f: F) -> F { - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { + | - change this to accept `FnMut` instead of `Fn` ... LL | let _f = to_fn(|| x = 42); | ----- -- ^^^^^^ cannot assign @@ -13,8 +13,8 @@ LL | let _f = to_fn(|| x = 42); error[E0596]: cannot borrow `y` as mutable, as it is a captured variable in a `Fn` closure --> $DIR/borrow-immutable-upvar-mutation.rs:24:31 | -LL | fn to_fn<A, F: Fn<A>>(f: F) -> F { - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { + | - change this to accept `FnMut` instead of `Fn` ... LL | let _g = to_fn(|| set(&mut y)); | ----- -- ^^^^^^ cannot borrow as mutable @@ -25,8 +25,8 @@ LL | let _g = to_fn(|| set(&mut y)); error[E0594]: cannot assign to `z`, as it is a captured variable in a `Fn` closure --> $DIR/borrow-immutable-upvar-mutation.rs:29:22 | -LL | fn to_fn<A, F: Fn<A>>(f: F) -> F { - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { + | - change this to accept `FnMut` instead of `Fn` ... LL | to_fn(|| z = 42); | ----- -- ^^^^^^ cannot assign @@ -37,8 +37,8 @@ LL | to_fn(|| z = 42); error[E0594]: cannot assign to `x`, as it is a captured variable in a `Fn` closure --> $DIR/borrow-immutable-upvar-mutation.rs:36:32 | -LL | fn to_fn<A, F: Fn<A>>(f: F) -> F { - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { + | - change this to accept `FnMut` instead of `Fn` ... LL | let _f = to_fn(move || x = 42); | ----- ------- ^^^^^^ cannot assign @@ -49,8 +49,8 @@ LL | let _f = to_fn(move || x = 42); error[E0596]: cannot borrow `y` as mutable, as it is a captured variable in a `Fn` closure --> $DIR/borrow-immutable-upvar-mutation.rs:39:36 | -LL | fn to_fn<A, F: Fn<A>>(f: F) -> F { - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { + | - change this to accept `FnMut` instead of `Fn` ... LL | let _g = to_fn(move || set(&mut y)); | ----- ------- ^^^^^^ cannot borrow as mutable @@ -61,8 +61,8 @@ LL | let _g = to_fn(move || set(&mut y)); error[E0594]: cannot assign to `z`, as it is a captured variable in a `Fn` closure --> $DIR/borrow-immutable-upvar-mutation.rs:44:27 | -LL | fn to_fn<A, F: Fn<A>>(f: F) -> F { - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A: std::marker::Tuple, F: Fn<A>>(f: F) -> F { + | - change this to accept `FnMut` instead of `Fn` ... LL | to_fn(move || z = 42); | ----- ------- ^^^^^^ cannot assign diff --git a/src/test/ui/borrowck/borrowck-move-by-capture.rs b/src/test/ui/borrowck/borrowck-move-by-capture.rs index f26edef17f3..6f0eb1870f3 100644 --- a/src/test/ui/borrowck/borrowck-move-by-capture.rs +++ b/src/test/ui/borrowck/borrowck-move-by-capture.rs @@ -1,7 +1,7 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] -fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f } -fn to_fn_once<A,F:FnOnce<A>>(f: F) -> F { f } +fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f } +fn to_fn_once<A:std::marker::Tuple,F:FnOnce<A>>(f: F) -> F { f } pub fn main() { let bar: Box<_> = Box::new(3); diff --git a/src/test/ui/c-variadic/issue-86053-1.stderr b/src/test/ui/c-variadic/issue-86053-1.stderr index 60b379faf4e..075bd1fc488 100644 --- a/src/test/ui/c-variadic/issue-86053-1.stderr +++ b/src/test/ui/c-variadic/issue-86053-1.stderr @@ -66,8 +66,8 @@ LL | self , ... , self , self , ... ) where F : FnOnce ( & 'a & 'b usize | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here | help: a trait with a similar name exists | diff --git a/src/test/ui/cannot-mutate-captured-non-mut-var.rs b/src/test/ui/cannot-mutate-captured-non-mut-var.rs index a83884acb1d..952dab25bf9 100644 --- a/src/test/ui/cannot-mutate-captured-non-mut-var.rs +++ b/src/test/ui/cannot-mutate-captured-non-mut-var.rs @@ -1,8 +1,8 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] use std::io::Read; -fn to_fn_once<A,F:FnOnce<A>>(f: F) -> F { f } +fn to_fn_once<A:std::marker::Tuple,F:FnOnce<A>>(f: F) -> F { f } fn main() { let x = 1; diff --git a/src/test/ui/chalkify/closure.rs b/src/test/ui/chalkify/closure.rs index 81114d491d7..408e8802d86 100644 --- a/src/test/ui/chalkify/closure.rs +++ b/src/test/ui/chalkify/closure.rs @@ -1,4 +1,5 @@ -// check-fail +// known-bug: unknown +// FIXME(chalk): Chalk needs support for the Tuple trait // compile-flags: -Z chalk fn main() -> () { @@ -25,7 +26,7 @@ fn main() -> () { let mut c = b; c(); - b(); //~ ERROR + b(); // FIXME: reenable when this is fixed ~ ERROR // FIXME(chalk): this doesn't quite work /* diff --git a/src/test/ui/chalkify/closure.stderr b/src/test/ui/chalkify/closure.stderr index 515e0cf0142..bcee0cab96a 100644 --- a/src/test/ui/chalkify/closure.stderr +++ b/src/test/ui/chalkify/closure.stderr @@ -1,22 +1,80 @@ -error[E0382]: borrow of moved value: `b` - --> $DIR/closure.rs:28:5 +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:7:5 + | +LL | t(); + | ^^^ the trait `Tuple` is not implemented for `()` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ + +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:13:5 + | +LL | b(); + | ^^^ the trait `Tuple` is not implemented for `()` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ + +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:17:5 + | +LL | c(); + | ^^^ the trait `Tuple` is not implemented for `()` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ + +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:18:5 | -LL | let mut c = b; - | - value moved here -... LL | b(); - | ^ value borrowed here after move + | ^^^ the trait `Tuple` is not implemented for `()` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ + +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:24:5 + | +LL | b(); + | ^^^ the trait `Tuple` is not implemented for `()` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ + +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:28:5 + | +LL | c(); + | ^^^ the trait `Tuple` is not implemented for `()` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ + +error[E0277]: `()` is not a tuple + --> $DIR/closure.rs:29:5 | -note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `a` out of its environment - --> $DIR/closure.rs:21:9 +LL | b(); // FIXME: reenable when this is fixed ~ ERROR + | ^^^ the trait `Tuple` is not implemented for `()` | -LL | a = 1; - | ^ -help: consider mutably borrowing `b` +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement | -LL | let mut c = &mut b; - | ++++ +LL | fn main() -> () where (): Tuple { + | +++++++++++++++ -error: aborting due to previous error +error: aborting due to 7 previous errors -For more information about this error, try `rustc --explain E0382`. +For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/chalkify/trait-objects.rs b/src/test/ui/chalkify/trait-objects.rs index d56abc42bf5..30929e943bd 100644 --- a/src/test/ui/chalkify/trait-objects.rs +++ b/src/test/ui/chalkify/trait-objects.rs @@ -1,4 +1,5 @@ -// check-pass +// known-bug: unknown +// FIXME(chalk): Chalk needs support for the Tuple trait // compile-flags: -Z chalk use std::fmt::Display; diff --git a/src/test/ui/chalkify/trait-objects.stderr b/src/test/ui/chalkify/trait-objects.stderr new file mode 100644 index 00000000000..098bd2d3226 --- /dev/null +++ b/src/test/ui/chalkify/trait-objects.stderr @@ -0,0 +1,28 @@ +error: the type `&dyn Fn(i32) -> _` is not well-formed (chalk) + --> $DIR/trait-objects.rs:11:12 + | +LL | let f: &dyn Fn(i32) -> _ = &|x| x + x; + | ^^^^^^^^^^^^^^^^^ + +error[E0277]: `(i32,)` is not a tuple + --> $DIR/trait-objects.rs:12:5 + | +LL | f(2); + | ^^^^ the trait `Tuple` is not implemented for `(i32,)` + | +help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement + | +LL | fn main() where (i32,): Tuple { + | +++++++++++++++++++ + +error[E0277]: expected a `Fn<(i32,)>` closure, found `dyn Fn(i32) -> i32` + --> $DIR/trait-objects.rs:12:5 + | +LL | f(2); + | ^^^^ expected an `Fn<(i32,)>` closure, found `dyn Fn(i32) -> i32` + | + = help: the trait `Fn<(i32,)>` is not implemented for `dyn Fn(i32) -> i32` + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/closures/issue-78720.stderr b/src/test/ui/closures/issue-78720.stderr index 3dd13877298..da3f539a007 100644 --- a/src/test/ui/closures/issue-78720.stderr +++ b/src/test/ui/closures/issue-78720.stderr @@ -12,8 +12,8 @@ LL | _func: F, | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here | help: a trait with a similar name exists | diff --git a/src/test/ui/error-codes/E0059.stderr b/src/test/ui/error-codes/E0059.stderr index a1b8aeaedbb..f331d014226 100644 --- a/src/test/ui/error-codes/E0059.stderr +++ b/src/test/ui/error-codes/E0059.stderr @@ -1,8 +1,14 @@ -error[E0059]: cannot use call notation; the first type parameter for the function trait is neither a tuple nor unit - --> $DIR/E0059.rs:3:41 +error[E0059]: type parameter to bare `Fn` trait must be a tuple + --> $DIR/E0059.rs:3:11 | LL | fn foo<F: Fn<i32>>(f: F) -> F::Output { f(3) } - | ^^^^ + | ^^^^^^^ the trait `Tuple` is not implemented for `i32` + | +note: required by a bound in `Fn` + --> $SRC_DIR/core/src/ops/function.rs:LL:COL + | +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | ^^^^^ required by this bound in `Fn` error: aborting due to previous error diff --git a/src/test/ui/feature-gates/feature-gate-abi.rs b/src/test/ui/feature-gates/feature-gate-abi.rs index 855263595d0..15b674c62e4 100644 --- a/src/test/ui/feature-gates/feature-gate-abi.rs +++ b/src/test/ui/feature-gates/feature-gate-abi.rs @@ -9,6 +9,9 @@ #[lang="sized"] trait Sized { } +#[lang="tuple_trait"] +trait Tuple { } + // Functions extern "rust-intrinsic" fn f1() {} //~ ERROR intrinsics are subject to change //~^ ERROR intrinsic must be in diff --git a/src/test/ui/feature-gates/feature-gate-abi.stderr b/src/test/ui/feature-gates/feature-gate-abi.stderr index bcca39c8fb8..33ec250f090 100644 --- a/src/test/ui/feature-gates/feature-gate-abi.stderr +++ b/src/test/ui/feature-gates/feature-gate-abi.stderr @@ -1,5 +1,5 @@ error[E0658]: intrinsics are subject to change - --> $DIR/feature-gate-abi.rs:13:8 + --> $DIR/feature-gate-abi.rs:16:8 | LL | extern "rust-intrinsic" fn f1() {} | ^^^^^^^^^^^^^^^^ @@ -7,7 +7,7 @@ LL | extern "rust-intrinsic" fn f1() {} = help: add `#![feature(intrinsics)]` to the crate attributes to enable error[E0658]: platform intrinsics are experimental and possibly buggy - --> $DIR/feature-gate-abi.rs:15:8 + --> $DIR/feature-gate-abi.rs:18:8 | LL | extern "platform-intrinsic" fn f2() {} | ^^^^^^^^^^^^^^^^^^^^ @@ -16,7 +16,7 @@ LL | extern "platform-intrinsic" fn f2() {} = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:17:8 + --> $DIR/feature-gate-abi.rs:20:8 | LL | extern "rust-call" fn f4(_: ()) {} | ^^^^^^^^^^^ @@ -25,7 +25,7 @@ LL | extern "rust-call" fn f4(_: ()) {} = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:18:8 + --> $DIR/feature-gate-abi.rs:21:8 | LL | extern "efiapi" fn f10() {} | ^^^^^^^^ @@ -34,7 +34,7 @@ LL | extern "efiapi" fn f10() {} = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error[E0658]: intrinsics are subject to change - --> $DIR/feature-gate-abi.rs:22:12 + --> $DIR/feature-gate-abi.rs:25:12 | LL | extern "rust-intrinsic" fn m1(); | ^^^^^^^^^^^^^^^^ @@ -42,7 +42,7 @@ LL | extern "rust-intrinsic" fn m1(); = help: add `#![feature(intrinsics)]` to the crate attributes to enable error[E0658]: platform intrinsics are experimental and possibly buggy - --> $DIR/feature-gate-abi.rs:24:12 + --> $DIR/feature-gate-abi.rs:27:12 | LL | extern "platform-intrinsic" fn m2(); | ^^^^^^^^^^^^^^^^^^^^ @@ -51,7 +51,7 @@ LL | extern "platform-intrinsic" fn m2(); = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:26:12 + --> $DIR/feature-gate-abi.rs:29:12 | LL | extern "rust-call" fn m4(_: ()); | ^^^^^^^^^^^ @@ -60,7 +60,7 @@ LL | extern "rust-call" fn m4(_: ()); = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:27:12 + --> $DIR/feature-gate-abi.rs:30:12 | LL | extern "efiapi" fn m10(); | ^^^^^^^^ @@ -69,7 +69,7 @@ LL | extern "efiapi" fn m10(); = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:29:12 + --> $DIR/feature-gate-abi.rs:32:12 | LL | extern "rust-call" fn dm4(_: ()) {} | ^^^^^^^^^^^ @@ -78,7 +78,7 @@ LL | extern "rust-call" fn dm4(_: ()) {} = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:30:12 + --> $DIR/feature-gate-abi.rs:33:12 | LL | extern "efiapi" fn dm10() {} | ^^^^^^^^ @@ -87,7 +87,7 @@ LL | extern "efiapi" fn dm10() {} = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error[E0658]: intrinsics are subject to change - --> $DIR/feature-gate-abi.rs:37:12 + --> $DIR/feature-gate-abi.rs:40:12 | LL | extern "rust-intrinsic" fn m1() {} | ^^^^^^^^^^^^^^^^ @@ -95,7 +95,7 @@ LL | extern "rust-intrinsic" fn m1() {} = help: add `#![feature(intrinsics)]` to the crate attributes to enable error[E0658]: platform intrinsics are experimental and possibly buggy - --> $DIR/feature-gate-abi.rs:39:12 + --> $DIR/feature-gate-abi.rs:42:12 | LL | extern "platform-intrinsic" fn m2() {} | ^^^^^^^^^^^^^^^^^^^^ @@ -104,7 +104,7 @@ LL | extern "platform-intrinsic" fn m2() {} = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:41:12 + --> $DIR/feature-gate-abi.rs:44:12 | LL | extern "rust-call" fn m4(_: ()) {} | ^^^^^^^^^^^ @@ -113,7 +113,7 @@ LL | extern "rust-call" fn m4(_: ()) {} = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:42:12 + --> $DIR/feature-gate-abi.rs:45:12 | LL | extern "efiapi" fn m10() {} | ^^^^^^^^ @@ -122,7 +122,7 @@ LL | extern "efiapi" fn m10() {} = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error[E0658]: intrinsics are subject to change - --> $DIR/feature-gate-abi.rs:47:12 + --> $DIR/feature-gate-abi.rs:50:12 | LL | extern "rust-intrinsic" fn im1() {} | ^^^^^^^^^^^^^^^^ @@ -130,7 +130,7 @@ LL | extern "rust-intrinsic" fn im1() {} = help: add `#![feature(intrinsics)]` to the crate attributes to enable error[E0658]: platform intrinsics are experimental and possibly buggy - --> $DIR/feature-gate-abi.rs:49:12 + --> $DIR/feature-gate-abi.rs:52:12 | LL | extern "platform-intrinsic" fn im2() {} | ^^^^^^^^^^^^^^^^^^^^ @@ -139,7 +139,7 @@ LL | extern "platform-intrinsic" fn im2() {} = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:51:12 + --> $DIR/feature-gate-abi.rs:54:12 | LL | extern "rust-call" fn im4(_: ()) {} | ^^^^^^^^^^^ @@ -148,7 +148,7 @@ LL | extern "rust-call" fn im4(_: ()) {} = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:52:12 + --> $DIR/feature-gate-abi.rs:55:12 | LL | extern "efiapi" fn im10() {} | ^^^^^^^^ @@ -157,7 +157,7 @@ LL | extern "efiapi" fn im10() {} = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error[E0658]: intrinsics are subject to change - --> $DIR/feature-gate-abi.rs:56:18 + --> $DIR/feature-gate-abi.rs:59:18 | LL | type A1 = extern "rust-intrinsic" fn(); | ^^^^^^^^^^^^^^^^ @@ -165,7 +165,7 @@ LL | type A1 = extern "rust-intrinsic" fn(); = help: add `#![feature(intrinsics)]` to the crate attributes to enable error[E0658]: platform intrinsics are experimental and possibly buggy - --> $DIR/feature-gate-abi.rs:57:18 + --> $DIR/feature-gate-abi.rs:60:18 | LL | type A2 = extern "platform-intrinsic" fn(); | ^^^^^^^^^^^^^^^^^^^^ @@ -174,7 +174,7 @@ LL | type A2 = extern "platform-intrinsic" fn(); = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:58:18 + --> $DIR/feature-gate-abi.rs:61:18 | LL | type A4 = extern "rust-call" fn(_: ()); | ^^^^^^^^^^^ @@ -183,7 +183,7 @@ LL | type A4 = extern "rust-call" fn(_: ()); = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:59:19 + --> $DIR/feature-gate-abi.rs:62:19 | LL | type A10 = extern "efiapi" fn(); | ^^^^^^^^ @@ -192,7 +192,7 @@ LL | type A10 = extern "efiapi" fn(); = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error[E0658]: intrinsics are subject to change - --> $DIR/feature-gate-abi.rs:62:8 + --> $DIR/feature-gate-abi.rs:65:8 | LL | extern "rust-intrinsic" {} | ^^^^^^^^^^^^^^^^ @@ -200,7 +200,7 @@ LL | extern "rust-intrinsic" {} = help: add `#![feature(intrinsics)]` to the crate attributes to enable error[E0658]: platform intrinsics are experimental and possibly buggy - --> $DIR/feature-gate-abi.rs:63:8 + --> $DIR/feature-gate-abi.rs:66:8 | LL | extern "platform-intrinsic" {} | ^^^^^^^^^^^^^^^^^^^^ @@ -209,7 +209,7 @@ LL | extern "platform-intrinsic" {} = help: add `#![feature(platform_intrinsics)]` to the crate attributes to enable error[E0658]: rust-call ABI is subject to change - --> $DIR/feature-gate-abi.rs:64:8 + --> $DIR/feature-gate-abi.rs:67:8 | LL | extern "rust-call" {} | ^^^^^^^^^^^ @@ -218,7 +218,7 @@ LL | extern "rust-call" {} = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable error[E0658]: efiapi ABI is experimental and subject to change - --> $DIR/feature-gate-abi.rs:65:8 + --> $DIR/feature-gate-abi.rs:68:8 | LL | extern "efiapi" {} | ^^^^^^^^ @@ -227,49 +227,49 @@ LL | extern "efiapi" {} = help: add `#![feature(abi_efiapi)]` to the crate attributes to enable error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:22:32 + --> $DIR/feature-gate-abi.rs:25:32 | LL | extern "rust-intrinsic" fn m1(); | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:24:36 + --> $DIR/feature-gate-abi.rs:27:36 | LL | extern "platform-intrinsic" fn m2(); | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:13:33 + --> $DIR/feature-gate-abi.rs:16:33 | LL | extern "rust-intrinsic" fn f1() {} | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:15:37 + --> $DIR/feature-gate-abi.rs:18:37 | LL | extern "platform-intrinsic" fn f2() {} | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:37:37 + --> $DIR/feature-gate-abi.rs:40:37 | LL | extern "rust-intrinsic" fn m1() {} | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:39:41 + --> $DIR/feature-gate-abi.rs:42:41 | LL | extern "platform-intrinsic" fn m2() {} | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:47:38 + --> $DIR/feature-gate-abi.rs:50:38 | LL | extern "rust-intrinsic" fn im1() {} | ^^ error: intrinsic must be in `extern "rust-intrinsic" { ... }` block - --> $DIR/feature-gate-abi.rs:49:42 + --> $DIR/feature-gate-abi.rs:52:42 | LL | extern "platform-intrinsic" fn im2() {} | ^^ diff --git a/src/test/ui/function-pointer/unsized-ret.rs b/src/test/ui/function-pointer/unsized-ret.rs index 60af5769d6d..79009c5cb6c 100644 --- a/src/test/ui/function-pointer/unsized-ret.rs +++ b/src/test/ui/function-pointer/unsized-ret.rs @@ -1,7 +1,8 @@ #![feature(fn_traits)] #![feature(unboxed_closures)] +#![feature(tuple_trait)] -fn foo<F: Fn<T>, T>(f: Option<F>, t: T) { +fn foo<F: Fn<T>, T:std::marker::Tuple>(f: Option<F>, t: T) { let y = (f.unwrap()).call(t); } diff --git a/src/test/ui/function-pointer/unsized-ret.stderr b/src/test/ui/function-pointer/unsized-ret.stderr index bec3e2aa3fe..40bf7a3898a 100644 --- a/src/test/ui/function-pointer/unsized-ret.stderr +++ b/src/test/ui/function-pointer/unsized-ret.stderr @@ -1,5 +1,5 @@ error[E0277]: the size for values of type `str` cannot be known at compilation time - --> $DIR/unsized-ret.rs:9:27 + --> $DIR/unsized-ret.rs:10:27 | LL | foo::<fn() -> str, _>(None, ()); | --------------------- ^^^^ doesn't have a size known at compile-time @@ -9,13 +9,13 @@ LL | foo::<fn() -> str, _>(None, ()); = help: within `fn() -> str`, the trait `Sized` is not implemented for `str` = note: required because it appears within the type `fn() -> str` note: required by a bound in `foo` - --> $DIR/unsized-ret.rs:4:11 + --> $DIR/unsized-ret.rs:5:11 | -LL | fn foo<F: Fn<T>, T>(f: Option<F>, t: T) { +LL | fn foo<F: Fn<T>, T:std::marker::Tuple>(f: Option<F>, t: T) { | ^^^^^ required by this bound in `foo` error[E0277]: the size for values of type `(dyn std::fmt::Display + 'a)` cannot be known at compilation time - --> $DIR/unsized-ret.rs:12:66 + --> $DIR/unsized-ret.rs:13:66 | LL | foo::<for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a), _>(None, (&(),)); | ------------------------------------------------------------ ^^^^ doesn't have a size known at compile-time @@ -25,9 +25,9 @@ LL | foo::<for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a), _>(None, (&() = help: within `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)`, the trait `for<'a> Sized` is not implemented for `(dyn std::fmt::Display + 'a)` = note: required because it appears within the type `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)` note: required by a bound in `foo` - --> $DIR/unsized-ret.rs:4:11 + --> $DIR/unsized-ret.rs:5:11 | -LL | fn foo<F: Fn<T>, T>(f: Option<F>, t: T) { +LL | fn foo<F: Fn<T>, T:std::marker::Tuple>(f: Option<F>, t: T) { | ^^^^^ required by this bound in `foo` error: aborting due to 2 previous errors diff --git a/src/test/ui/issues/issue-12127.rs b/src/test/ui/issues/issue-12127.rs index 8b30ddc2de6..199d542e816 100644 --- a/src/test/ui/issues/issue-12127.rs +++ b/src/test/ui/issues/issue-12127.rs @@ -1,6 +1,6 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] -fn to_fn_once<A,F:FnOnce<A>>(f: F) -> F { f } +fn to_fn_once<A:std::marker::Tuple,F:FnOnce<A>>(f: F) -> F { f } fn do_it(x: &isize) { } fn main() { diff --git a/src/test/ui/issues/issue-23024.stderr b/src/test/ui/issues/issue-23024.stderr index 73f93c51d34..dc8b34a70c3 100644 --- a/src/test/ui/issues/issue-23024.stderr +++ b/src/test/ui/issues/issue-23024.stderr @@ -16,7 +16,7 @@ LL | println!("{:?}",(vfnfer[0] as dyn Fn)(3)); note: trait defined here, with 1 generic parameter: `Args` --> $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { | ^^ ---- help: add missing generic argument | diff --git a/src/test/ui/issues/issue-7607-1.stderr b/src/test/ui/issues/issue-7607-1.stderr index ecff8b42b0e..f1ab0ad26d7 100644 --- a/src/test/ui/issues/issue-7607-1.stderr +++ b/src/test/ui/issues/issue-7607-1.stderr @@ -6,8 +6,8 @@ LL | impl Fo { | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here error: aborting due to previous error diff --git a/src/test/ui/lang-items/lang-item-missing-generator.rs b/src/test/ui/lang-items/lang-item-missing-generator.rs index 0c329542928..9b9aff38e52 100644 --- a/src/test/ui/lang-items/lang-item-missing-generator.rs +++ b/src/test/ui/lang-items/lang-item-missing-generator.rs @@ -1,12 +1,14 @@ // error-pattern: requires `generator` lang_item -#![feature(no_core, lang_items, unboxed_closures)] +#![feature(no_core, lang_items, unboxed_closures, tuple_trait)] #![no_core] #[lang = "sized"] pub trait Sized { } +#[lang = "tuple_trait"] pub trait Tuple { } + #[lang = "fn_once"] #[rustc_paren_sugar] -pub trait FnOnce<Args> { +pub trait FnOnce<Args: Tuple> { type Output; extern "rust-call" fn call_once(self, args: Args) -> Self::Output; diff --git a/src/test/ui/lang-items/lang-item-missing-generator.stderr b/src/test/ui/lang-items/lang-item-missing-generator.stderr index fa13bf0b127..a24fdb5fb65 100644 --- a/src/test/ui/lang-items/lang-item-missing-generator.stderr +++ b/src/test/ui/lang-items/lang-item-missing-generator.stderr @@ -1,8 +1,15 @@ +error[E0635]: unknown feature `tuple_trait` + --> $DIR/lang-item-missing-generator.rs:2:51 + | +LL | #![feature(no_core, lang_items, unboxed_closures, tuple_trait)] + | ^^^^^^^^^^^ + error: requires `generator` lang_item - --> $DIR/lang-item-missing-generator.rs:15:17 + --> $DIR/lang-item-missing-generator.rs:17:17 | LL | pub fn abc() -> impl FnOnce(f32) { | ^^^^^^^^^^^^^^^^ -error: aborting due to previous error +error: aborting due to 2 previous errors +For more information about this error, try `rustc --explain E0635`. diff --git a/src/test/ui/mismatched_types/unboxed-closures-vtable-mismatch.rs b/src/test/ui/mismatched_types/unboxed-closures-vtable-mismatch.rs index 8dbe3472ea8..307104e47a1 100644 --- a/src/test/ui/mismatched_types/unboxed-closures-vtable-mismatch.rs +++ b/src/test/ui/mismatched_types/unboxed-closures-vtable-mismatch.rs @@ -1,8 +1,8 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures,tuple_trait)] use std::ops::FnMut; -fn to_fn_mut<A, F: FnMut<A>>(f: F) -> F { f } +fn to_fn_mut<A:std::marker::Tuple, F:FnMut<A>>(f: F) -> F { f } fn call_it<F: FnMut(isize, isize) -> isize>(y: isize, mut f: F) -> isize { //~^ NOTE required by this bound in `call_it` diff --git a/src/test/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.rs b/src/test/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.rs index 76b7aab542d..490d91ac118 100644 --- a/src/test/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.rs +++ b/src/test/ui/moves/moves-based-on-type-move-out-of-closure-env-issue-1965.rs @@ -1,6 +1,6 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] -fn to_fn<A,F:Fn<A>>(f: F) -> F { f } +fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f } fn test(_x: Box<usize>) {} diff --git a/src/test/ui/overloaded/overloaded-calls-nontuple.rs b/src/test/ui/overloaded/overloaded-calls-nontuple.rs index 07d44ff82b1..32a3b93e0a1 100644 --- a/src/test/ui/overloaded/overloaded-calls-nontuple.rs +++ b/src/test/ui/overloaded/overloaded-calls-nontuple.rs @@ -8,22 +8,23 @@ struct S { } impl FnMut<isize> for S { + //~^ ERROR type parameter to bare `FnMut` trait must be a tuple extern "rust-call" fn call_mut(&mut self, z: isize) -> isize { + //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument self.x + self.y + z } - //~^^^ ERROR functions with the "rust-call" ABI must take a single non-self argument } impl FnOnce<isize> for S { + //~^ ERROR type parameter to bare `FnOnce` trait must be a tuple type Output = isize; - extern "rust-call" fn call_once(mut self, z: isize) -> isize { self.call_mut(z) } - //~^ ERROR functions with the "rust-call" ABI must take a single non-self argument + extern "rust-call" fn call_once(mut self, z: isize) -> isize { + //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument + self.call_mut(z) + } } fn main() { - let mut s = S { - x: 1, - y: 2, - }; - drop(s(3)) //~ ERROR cannot use call notation + let mut s = S { x: 1, y: 2 }; + drop(s(3)) } diff --git a/src/test/ui/overloaded/overloaded-calls-nontuple.stderr b/src/test/ui/overloaded/overloaded-calls-nontuple.stderr index 8f299bc9434..794535aeb11 100644 --- a/src/test/ui/overloaded/overloaded-calls-nontuple.stderr +++ b/src/test/ui/overloaded/overloaded-calls-nontuple.stderr @@ -1,21 +1,40 @@ -error: functions with the "rust-call" ABI must take a single non-self argument that is a tuple - --> $DIR/overloaded-calls-nontuple.rs:11:5 +error[E0059]: type parameter to bare `FnMut` trait must be a tuple + --> $DIR/overloaded-calls-nontuple.rs:10:6 | -LL | extern "rust-call" fn call_mut(&mut self, z: isize) -> isize { - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | impl FnMut<isize> for S { + | ^^^^^^^^^^^^ the trait `Tuple` is not implemented for `isize` + | +note: required by a bound in `FnMut` + --> $SRC_DIR/core/src/ops/function.rs:LL:COL + | +LL | pub trait FnMut<Args: Tuple>: FnOnce<Args> { + | ^^^^^ required by this bound in `FnMut` + +error[E0059]: type parameter to bare `FnOnce` trait must be a tuple + --> $DIR/overloaded-calls-nontuple.rs:18:6 + | +LL | impl FnOnce<isize> for S { + | ^^^^^^^^^^^^^ the trait `Tuple` is not implemented for `isize` + | +note: required by a bound in `FnOnce` + --> $SRC_DIR/core/src/ops/function.rs:LL:COL + | +LL | pub trait FnOnce<Args: Tuple> { + | ^^^^^ required by this bound in `FnOnce` -error: functions with the "rust-call" ABI must take a single non-self argument that is a tuple - --> $DIR/overloaded-calls-nontuple.rs:19:5 +error[E0277]: functions with the "rust-call" ABI must take a single non-self tuple argument + --> $DIR/overloaded-calls-nontuple.rs:12:5 | -LL | extern "rust-call" fn call_once(mut self, z: isize) -> isize { self.call_mut(z) } - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | extern "rust-call" fn call_mut(&mut self, z: isize) -> isize { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Tuple` is not implemented for `isize` -error[E0059]: cannot use call notation; the first type parameter for the function trait is neither a tuple nor unit - --> $DIR/overloaded-calls-nontuple.rs:28:10 +error[E0277]: functions with the "rust-call" ABI must take a single non-self tuple argument + --> $DIR/overloaded-calls-nontuple.rs:21:5 | -LL | drop(s(3)) - | ^^^^ +LL | extern "rust-call" fn call_once(mut self, z: isize) -> isize { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Tuple` is not implemented for `isize` -error: aborting due to 3 previous errors +error: aborting due to 4 previous errors -For more information about this error, try `rustc --explain E0059`. +Some errors have detailed explanations: E0059, E0277. +For more information about an error, try `rustc --explain E0059`. diff --git a/src/test/ui/parser/kw-in-trait-bounds.stderr b/src/test/ui/parser/kw-in-trait-bounds.stderr index 28196c7ce2d..546ad84eeee 100644 --- a/src/test/ui/parser/kw-in-trait-bounds.stderr +++ b/src/test/ui/parser/kw-in-trait-bounds.stderr @@ -94,8 +94,8 @@ LL | fn _f<F: fn(), G>(_: impl fn(), _: &dyn fn()) | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here error[E0405]: cannot find trait `r#fn` in this scope --> $DIR/kw-in-trait-bounds.rs:17:4 @@ -105,8 +105,8 @@ LL | G: fn(), | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here error[E0405]: cannot find trait `r#fn` in this scope --> $DIR/kw-in-trait-bounds.rs:3:27 @@ -116,8 +116,8 @@ LL | fn _f<F: fn(), G>(_: impl fn(), _: &dyn fn()) | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here error[E0405]: cannot find trait `r#fn` in this scope --> $DIR/kw-in-trait-bounds.rs:3:41 @@ -127,8 +127,8 @@ LL | fn _f<F: fn(), G>(_: impl fn(), _: &dyn fn()) | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here error[E0405]: cannot find trait `r#struct` in this scope --> $DIR/kw-in-trait-bounds.rs:24:10 diff --git a/src/test/ui/span/issue-11925.rs b/src/test/ui/span/issue-11925.rs index d9c08fbdd0f..cac9fd5bfb6 100644 --- a/src/test/ui/span/issue-11925.rs +++ b/src/test/ui/span/issue-11925.rs @@ -1,6 +1,6 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] -fn to_fn_once<A,F:FnOnce<A>>(f: F) -> F { f } +fn to_fn_once<A:std::marker::Tuple,F:FnOnce<A>>(f: F) -> F { f } fn main() { let r = { diff --git a/src/test/ui/typeck/issue-83693.stderr b/src/test/ui/typeck/issue-83693.stderr index 0d8bbf1ce98..1e45c2d35df 100644 --- a/src/test/ui/typeck/issue-83693.stderr +++ b/src/test/ui/typeck/issue-83693.stderr @@ -6,8 +6,8 @@ LL | impl F { | ::: $SRC_DIR/core/src/ops/function.rs:LL:COL | -LL | pub trait Fn<Args>: FnMut<Args> { - | ------------------------------- similarly named trait `Fn` defined here +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | -------------------------------------- similarly named trait `Fn` defined here error[E0412]: cannot find type `TestResult` in this scope --> $DIR/issue-83693.rs:9:22 diff --git a/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.rs b/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.rs index 925463d6dee..d2e48600227 100644 --- a/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.rs +++ b/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.rs @@ -1,8 +1,8 @@ #![feature(unboxed_closures)] fn a<F: Fn<usize>>(f: F) {} +//~^ ERROR type parameter to bare `Fn` trait must be a tuple fn main() { a(|_: usize| {}); - //~^ ERROR mismatched types } diff --git a/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.stderr b/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.stderr index 9a24fb8c2be..1c18eb0fc49 100644 --- a/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.stderr +++ b/src/test/ui/unboxed-closures/non-tupled-arg-mismatch.stderr @@ -1,17 +1,15 @@ -error[E0308]: mismatched types - --> $DIR/non-tupled-arg-mismatch.rs:6:5 - | -LL | a(|_: usize| {}); - | ^ types differ - | - = note: expected trait `Fn<usize>` - found trait `Fn<(usize,)>` -note: required by a bound in `a` +error[E0059]: type parameter to bare `Fn` trait must be a tuple --> $DIR/non-tupled-arg-mismatch.rs:3:9 | LL | fn a<F: Fn<usize>>(f: F) {} - | ^^^^^^^^^ required by this bound in `a` + | ^^^^^^^^^ the trait `Tuple` is not implemented for `usize` + | +note: required by a bound in `Fn` + --> $SRC_DIR/core/src/ops/function.rs:LL:COL + | +LL | pub trait Fn<Args: Tuple>: FnMut<Args> { + | ^^^^^ required by this bound in `Fn` error: aborting due to previous error -For more information about this error, try `rustc --explain E0308`. +For more information about this error, try `rustc --explain E0059`. diff --git a/src/test/ui/unboxed-closures/unboxed-closure-illegal-move.rs b/src/test/ui/unboxed-closures/unboxed-closure-illegal-move.rs index ed8d7211461..7377359b6b0 100644 --- a/src/test/ui/unboxed-closures/unboxed-closure-illegal-move.rs +++ b/src/test/ui/unboxed-closures/unboxed-closure-illegal-move.rs @@ -1,12 +1,12 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] // Tests that we can't move out of an unboxed closure environment // if the upvar is captured by ref or the closure takes self by // reference. -fn to_fn<A,F:Fn<A>>(f: F) -> F { f } -fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f } -fn to_fn_once<A,F:FnOnce<A>>(f: F) -> F { f } +fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f } +fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f } +fn to_fn_once<A:std::marker::Tuple,F:FnOnce<A>>(f: F) -> F { f } fn main() { // By-ref cases diff --git a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.rs b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.rs index 57e6d30658c..c57312b4387 100644 --- a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.rs +++ b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.rs @@ -2,12 +2,12 @@ // as `mut` through a closure. Also test that we CAN mutate a moved copy, // unless this is a `Fn` closure. Issue #16749. -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] use std::mem; -fn to_fn<A,F:Fn<A>>(f: F) -> F { f } -fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f } +fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f } +fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f } fn a() { let n = 0; diff --git a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr index d6e74b5b8b9..26f97b51913 100644 --- a/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr +++ b/src/test/ui/unboxed-closures/unboxed-closures-mutate-upvar.stderr @@ -28,8 +28,8 @@ LL | n += 1; error[E0594]: cannot assign to `n`, as it is a captured variable in a `Fn` closure --> $DIR/unboxed-closures-mutate-upvar.rs:53:9 | -LL | fn to_fn<A,F:Fn<A>>(f: F) -> F { f } - | - change this to accept `FnMut` instead of `Fn` +LL | fn to_fn<A:std::marker::Tuple,F:Fn<A>>(f: F) -> F { f } + | - change this to accept `FnMut` instead of `Fn` ... LL | let mut f = to_fn(move || { | ----- ------- in this closure diff --git a/src/test/ui/unboxed-closures/unboxed-closures-static-call-wrong-trait.rs b/src/test/ui/unboxed-closures/unboxed-closures-static-call-wrong-trait.rs index 0e727b11cd2..7289d9322d0 100644 --- a/src/test/ui/unboxed-closures/unboxed-closures-static-call-wrong-trait.rs +++ b/src/test/ui/unboxed-closures/unboxed-closures-static-call-wrong-trait.rs @@ -1,6 +1,6 @@ -#![feature(unboxed_closures)] +#![feature(unboxed_closures, tuple_trait)] -fn to_fn_mut<A,F:FnMut<A>>(f: F) -> F { f } +fn to_fn_mut<A:std::marker::Tuple,F:FnMut<A>>(f: F) -> F { f } fn main() { let mut_ = to_fn_mut(|x| x); |