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| author | bors <bors@rust-lang.org> | 2025-07-01 21:50:21 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2025-07-01 21:50:21 +0000 |
| commit | 085c24790e591948f788fd294ca3f9858313741c (patch) | |
| tree | e49e165b6795628d465d1539dd1fe2ae0b4545de /compiler | |
| parent | 71e4c005caa812a16fcb08d0bf1e6f1eda7c8381 (diff) | |
| parent | 2516c339829cd9193c15464218a981b8547157ca (diff) | |
| download | rust-085c24790e591948f788fd294ca3f9858313741c.tar.gz rust-085c24790e591948f788fd294ca3f9858313741c.zip | |
Auto merge of #143036 - compiler-errors:no-dyn-star, r=oli-obk
Remove support for `dyn*` from the compiler
This PR removes support for `dyn*` (https://github.com/rust-lang/rust/issues/102425), which are a currently un-RFC'd experiment that was opened a few years ago to explore a component that we thought was necessary for AFIDT (async fn in dyn trait).
It doesn't seem like we are going to need `dyn*` types -- even in an not-exposed-to-the-user way[^1] -- for us to implement AFIDT. Given that AFIDT was the original motivating purpose of `dyn*` types, I don't really see a compelling reason to have to maintain their implementation in the compiler.
[^1]: Compared to, e.g., generators whih are an unstable building block we use to implement stable syntax like `async {}`.
We've learned quite a lot from `dyn*`, but I think at this point its current behavior leads to more questions than answers. For example, `dyn*` support today remains somewhat fragile; it ICEs in many cases where the current "normal" `dyn Trait` types rely on their unsizedness for their vtable-based implementation to be sound I wouldn't be surprised if it's unsound in other ways, though I didn't play around with it too much. See the examples below.
```rust
#![feature(dyn_star)]
trait Foo {
fn hello(self);
}
impl Foo for usize {
fn hello(self) {
println!("hello, world");
}
}
fn main() {
let x: dyn* Foo = 1usize;
x.hello();
}
```
And:
```rust
#![feature(dyn_star)]
trait Trait {
type Out where Self: Sized;
}
fn main() {
let x: <dyn* Trait as Trait>::Out;
}
```
...and probably many more problems having to do with the intersection of dyn-compatibility and `Self: Sized` bounds that I was too lazy to look into like:
* GATs
* Methods with invalid signatures
* Associated consts
Generally, `dyn*` types also end up getting in the way of working with [normal `dyn` types](https://github.com/rust-lang/rust/issues/102425#issuecomment-1712604409) to an extent that IMO outweighs the benefit of experimentation.
I recognize that there are probably other, more creative usages of `dyn*` that are orthogonal to AFIDT. However, I think any work along those lines should first have to think through some of the more fundamental interactions between `dyn*` and dyn-compatibility before we think about reimplementing them in the type system.
---
I'm planning on removing the `DynKind` enum and the `PointerLike` built-in trait from the compiler after this PR lands.
Closes rust-lang/rust#102425.
cc `@eholk` `@rust-lang/lang` `@rust-lang/types`
Closes rust-lang/rust#116979.
Closes rust-lang/rust#119694.
Closes rust-lang/rust#134591.
Closes rust-lang/rust#104800.
Diffstat (limited to 'compiler')
50 files changed, 52 insertions, 594 deletions
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs index f5418402377..286bbfb5ae8 100644 --- a/compiler/rustc_ast/src/ast.rs +++ b/compiler/rustc_ast/src/ast.rs @@ -2585,8 +2585,7 @@ pub enum TyPatKind { pub enum TraitObjectSyntax { // SAFETY: When adding new variants make sure to update the `Tag` impl. Dyn = 0, - DynStar = 1, - None = 2, + None = 1, } /// SAFETY: `TraitObjectSyntax` only has 3 data-less variants which means @@ -2602,8 +2601,7 @@ unsafe impl Tag for TraitObjectSyntax { unsafe fn from_usize(tag: usize) -> Self { match tag { 0 => TraitObjectSyntax::Dyn, - 1 => TraitObjectSyntax::DynStar, - 2 => TraitObjectSyntax::None, + 1 => TraitObjectSyntax::None, _ => unreachable!(), } } diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs index 1ec56868f37..c7f41fc3cb1 100644 --- a/compiler/rustc_ast_passes/src/feature_gate.rs +++ b/compiler/rustc_ast_passes/src/feature_gate.rs @@ -505,7 +505,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) { ); gate_all!(associated_const_equality, "associated const equality is incomplete"); gate_all!(yeet_expr, "`do yeet` expression is experimental"); - gate_all!(dyn_star, "`dyn*` trait objects are experimental"); gate_all!(const_closures, "const closures are experimental"); gate_all!(builtin_syntax, "`builtin #` syntax is unstable"); gate_all!(ergonomic_clones, "ergonomic clones are experimental"); diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs index 3d738fa31f2..9802ac90c9a 100644 --- a/compiler/rustc_ast_pretty/src/pprust/state.rs +++ b/compiler/rustc_ast_pretty/src/pprust/state.rs @@ -1303,7 +1303,6 @@ impl<'a> State<'a> { ast::TyKind::TraitObject(bounds, syntax) => { match syntax { ast::TraitObjectSyntax::Dyn => self.word_nbsp("dyn"), - ast::TraitObjectSyntax::DynStar => self.word_nbsp("dyn*"), ast::TraitObjectSyntax::None => {} } self.print_type_bounds(bounds); diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index e37b5a33af8..05bcd9f862e 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -25,9 +25,9 @@ use rustc_middle::traits::query::NoSolution; use rustc_middle::ty::adjustment::PointerCoercion; use rustc_middle::ty::cast::CastTy; use rustc_middle::ty::{ - self, Binder, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, CoroutineArgsExt, - Dynamic, GenericArgsRef, OpaqueHiddenType, OpaqueTypeKey, RegionVid, Ty, TyCtxt, - TypeVisitableExt, UserArgs, UserTypeAnnotationIndex, fold_regions, + self, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, CoroutineArgsExt, + GenericArgsRef, OpaqueHiddenType, OpaqueTypeKey, RegionVid, Ty, TyCtxt, TypeVisitableExt, + UserArgs, UserTypeAnnotationIndex, fold_regions, }; use rustc_middle::{bug, span_bug}; use rustc_mir_dataflow::move_paths::MoveData; @@ -1233,38 +1233,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { ); } - CastKind::PointerCoercion(PointerCoercion::DynStar, coercion_source) => { - // get the constraints from the target type (`dyn* Clone`) - // - // apply them to prove that the source type `Foo` implements `Clone` etc - let (existential_predicates, region) = match ty.kind() { - Dynamic(predicates, region, ty::DynStar) => (predicates, region), - _ => panic!("Invalid dyn* cast_ty"), - }; - - let self_ty = op.ty(self.body, tcx); - - let is_implicit_coercion = coercion_source == CoercionSource::Implicit; - self.prove_predicates( - existential_predicates - .iter() - .map(|predicate| predicate.with_self_ty(tcx, self_ty)), - location.to_locations(), - ConstraintCategory::Cast { is_implicit_coercion, unsize_to: None }, - ); - - let outlives_predicate = tcx.mk_predicate(Binder::dummy( - ty::PredicateKind::Clause(ty::ClauseKind::TypeOutlives( - ty::OutlivesPredicate(self_ty, *region), - )), - )); - self.prove_predicate( - outlives_predicate, - location.to_locations(), - ConstraintCategory::Cast { is_implicit_coercion, unsize_to: None }, - ); - } - CastKind::PointerCoercion( PointerCoercion::MutToConstPointer, coercion_source, diff --git a/compiler/rustc_codegen_cranelift/src/abi/mod.rs b/compiler/rustc_codegen_cranelift/src/abi/mod.rs index 4c6fd907815..8965e4a944d 100644 --- a/compiler/rustc_codegen_cranelift/src/abi/mod.rs +++ b/compiler/rustc_codegen_cranelift/src/abi/mod.rs @@ -753,51 +753,6 @@ pub(crate) fn codegen_drop<'tcx>( fx.bcx.ins().call_indirect(sig, drop_fn, &[ptr]); fx.bcx.ins().jump(ret_block, &[]); } - ty::Dynamic(_, _, ty::DynStar) => { - // IN THIS ARM, WE HAVE: - // ty = *mut (dyn* Trait) - // which is: *mut exists<T: sizeof(T) == sizeof(usize)> (T, Vtable<T: Trait>) - // - // args = [ * ] - // | - // v - // ( Data, Vtable ) - // | - // v - // /-------\ - // | ... | - // \-------/ - // - // - // WE CAN CONVERT THIS INTO THE ABOVE LOGIC BY DOING - // - // data = &(*args[0]).0 // gives a pointer to Data above (really the same pointer) - // vtable = (*args[0]).1 // loads the vtable out - // (data, vtable) // an equivalent Rust `*mut dyn Trait` - // - // SO THEN WE CAN USE THE ABOVE CODE. - let (data, vtable) = drop_place.to_cvalue(fx).dyn_star_force_data_on_stack(fx); - let drop_fn = crate::vtable::drop_fn_of_obj(fx, vtable); - - let is_null = fx.bcx.ins().icmp_imm(IntCC::Equal, drop_fn, 0); - let target_block = fx.get_block(target); - let continued = fx.bcx.create_block(); - fx.bcx.ins().brif(is_null, target_block, &[], continued, &[]); - fx.bcx.switch_to_block(continued); - - let virtual_drop = Instance { - def: ty::InstanceKind::Virtual(drop_instance.def_id(), 0), - args: drop_instance.args, - }; - let fn_abi = FullyMonomorphizedLayoutCx(fx.tcx) - .fn_abi_of_instance(virtual_drop, ty::List::empty()); - - let sig = clif_sig_from_fn_abi(fx.tcx, fx.target_config.default_call_conv, &fn_abi); - let sig = fx.bcx.import_signature(sig); - fx.bcx.ins().call_indirect(sig, drop_fn, &[data]); - // FIXME implement cleanup on exceptions - fx.bcx.ins().jump(ret_block, &[]); - } _ => { assert!(!matches!(drop_instance.def, InstanceKind::Virtual(_, _))); diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs index 1b68c6535da..bc0a0f034b2 100644 --- a/compiler/rustc_codegen_cranelift/src/base.rs +++ b/compiler/rustc_codegen_cranelift/src/base.rs @@ -790,14 +790,6 @@ fn codegen_stmt<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, cur_block: Block, stmt: let operand = codegen_operand(fx, operand); crate::unsize::coerce_unsized_into(fx, operand, lval); } - Rvalue::Cast( - CastKind::PointerCoercion(PointerCoercion::DynStar, _), - ref operand, - _, - ) => { - let operand = codegen_operand(fx, operand); - crate::unsize::coerce_dyn_star(fx, operand, lval); - } Rvalue::Cast(CastKind::Transmute, ref operand, _to_ty) => { let operand = codegen_operand(fx, operand); lval.write_cvalue_transmute(fx, operand); diff --git a/compiler/rustc_codegen_cranelift/src/unsize.rs b/compiler/rustc_codegen_cranelift/src/unsize.rs index df60b05c463..2aee0b2e974 100644 --- a/compiler/rustc_codegen_cranelift/src/unsize.rs +++ b/compiler/rustc_codegen_cranelift/src/unsize.rs @@ -112,21 +112,6 @@ fn unsize_ptr<'tcx>( } } -/// Coerces `src` to `dst_ty` which is guaranteed to be a `dyn*` type. -pub(crate) fn cast_to_dyn_star<'tcx>( - fx: &mut FunctionCx<'_, '_, 'tcx>, - src: Value, - src_ty_and_layout: TyAndLayout<'tcx>, - dst_ty: Ty<'tcx>, - old_info: Option<Value>, -) -> (Value, Value) { - assert!( - matches!(dst_ty.kind(), ty::Dynamic(_, _, ty::DynStar)), - "destination type must be a dyn*" - ); - (src, unsized_info(fx, src_ty_and_layout.ty, dst_ty, old_info)) -} - /// Coerce `src`, which is a reference to a value of type `src_ty`, /// to a value of type `dst_ty` and store the result in `dst` pub(crate) fn coerce_unsized_into<'tcx>( @@ -174,24 +159,6 @@ pub(crate) fn coerce_unsized_into<'tcx>( } } -pub(crate) fn coerce_dyn_star<'tcx>( - fx: &mut FunctionCx<'_, '_, 'tcx>, - src: CValue<'tcx>, - dst: CPlace<'tcx>, -) { - let (data, extra) = if let ty::Dynamic(_, _, ty::DynStar) = src.layout().ty.kind() { - let (data, vtable) = src.load_scalar_pair(fx); - (data, Some(vtable)) - } else { - let data = src.load_scalar(fx); - (data, None) - }; - - let (data, vtable) = cast_to_dyn_star(fx, data, src.layout(), dst.layout().ty, extra); - - dst.write_cvalue(fx, CValue::by_val_pair(data, vtable, dst.layout())); -} - // Adapted from https://github.com/rust-lang/rust/blob/2a663555ddf36f6b041445894a8c175cd1bc718c/src/librustc_codegen_ssa/glue.rs pub(crate) fn size_and_align_of<'tcx>( diff --git a/compiler/rustc_codegen_cranelift/src/value_and_place.rs b/compiler/rustc_codegen_cranelift/src/value_and_place.rs index cbfb215a892..9d73f200afe 100644 --- a/compiler/rustc_codegen_cranelift/src/value_and_place.rs +++ b/compiler/rustc_codegen_cranelift/src/value_and_place.rs @@ -121,43 +121,6 @@ impl<'tcx> CValue<'tcx> { } } - // FIXME remove - /// Forces the data value of a dyn* value to the stack and returns a pointer to it as well as the - /// vtable pointer. - pub(crate) fn dyn_star_force_data_on_stack( - self, - fx: &mut FunctionCx<'_, '_, 'tcx>, - ) -> (Value, Value) { - assert!(self.1.ty.is_dyn_star()); - - match self.0 { - CValueInner::ByRef(ptr, None) => { - let (a_scalar, b_scalar) = match self.1.backend_repr { - BackendRepr::ScalarPair(a, b) => (a, b), - _ => unreachable!("dyn_star_force_data_on_stack({:?})", self), - }; - let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar); - let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar); - let mut flags = MemFlags::new(); - flags.set_notrap(); - let vtable = ptr.offset(fx, b_offset).load(fx, clif_ty2, flags); - (ptr.get_addr(fx), vtable) - } - CValueInner::ByValPair(data, vtable) => { - let data_ptr = fx.create_stack_slot( - u32::try_from(fx.target_config.pointer_type().bytes()).unwrap(), - u32::try_from(fx.target_config.pointer_type().bytes()).unwrap(), - ); - data_ptr.store(fx, data, MemFlags::trusted()); - - (data_ptr.get_addr(fx), vtable) - } - CValueInner::ByRef(_, Some(_)) | CValueInner::ByVal(_) => { - unreachable!("dyn_star_force_data_on_stack({:?})", self) - } - } - } - pub(crate) fn try_to_ptr(self) -> Option<(Pointer, Option<Value>)> { match self.0 { CValueInner::ByRef(ptr, meta) => Some((ptr, meta)), diff --git a/compiler/rustc_codegen_cranelift/src/vtable.rs b/compiler/rustc_codegen_cranelift/src/vtable.rs index 1fae56949bc..423cc8d225b 100644 --- a/compiler/rustc_codegen_cranelift/src/vtable.rs +++ b/compiler/rustc_codegen_cranelift/src/vtable.rs @@ -46,34 +46,22 @@ pub(crate) fn get_ptr_and_method_ref<'tcx>( mut arg: CValue<'tcx>, idx: usize, ) -> (Pointer, Value) { - let (ptr, vtable) = 'block: { - if let BackendRepr::Scalar(_) = arg.layout().backend_repr { - while !arg.layout().ty.is_raw_ptr() && !arg.layout().ty.is_ref() { - let (idx, _) = arg - .layout() - .non_1zst_field(fx) - .expect("not exactly one non-1-ZST field in a `DispatchFromDyn` type"); - arg = arg.value_field(fx, idx); - } - } - - if let ty::Ref(_, ty, _) = arg.layout().ty.kind() { - if ty.is_dyn_star() { - let inner_layout = fx.layout_of(arg.layout().ty.builtin_deref(true).unwrap()); - let dyn_star = CPlace::for_ptr(Pointer::new(arg.load_scalar(fx)), inner_layout); - let ptr = dyn_star.place_field(fx, FieldIdx::ZERO).to_ptr(); - let vtable = dyn_star.place_field(fx, FieldIdx::ONE).to_cvalue(fx).load_scalar(fx); - break 'block (ptr, vtable); - } + if let BackendRepr::Scalar(_) = arg.layout().backend_repr { + while !arg.layout().ty.is_raw_ptr() && !arg.layout().ty.is_ref() { + let (idx, _) = arg + .layout() + .non_1zst_field(fx) + .expect("not exactly one non-1-ZST field in a `DispatchFromDyn` type"); + arg = arg.value_field(fx, idx); } + } - if let BackendRepr::ScalarPair(_, _) = arg.layout().backend_repr { - let (ptr, vtable) = arg.load_scalar_pair(fx); - (Pointer::new(ptr), vtable) - } else { - let (ptr, vtable) = arg.try_to_ptr().unwrap(); - (ptr, vtable.unwrap()) - } + let (ptr, vtable) = if let BackendRepr::ScalarPair(_, _) = arg.layout().backend_repr { + let (ptr, vtable) = arg.load_scalar_pair(fx); + (Pointer::new(ptr), vtable) + } else { + let (ptr, vtable) = arg.try_to_ptr().unwrap(); + (ptr, vtable.unwrap()) }; let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes(); diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs index b06cfd1e473..102d4ea2fa6 100644 --- a/compiler/rustc_codegen_ssa/src/base.rs +++ b/compiler/rustc_codegen_ssa/src/base.rs @@ -262,28 +262,6 @@ pub(crate) fn unsize_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( } } -/// Coerces `src` to `dst_ty` which is guaranteed to be a `dyn*` type. -pub(crate) fn cast_to_dyn_star<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( - bx: &mut Bx, - src: Bx::Value, - src_ty_and_layout: TyAndLayout<'tcx>, - dst_ty: Ty<'tcx>, - old_info: Option<Bx::Value>, -) -> (Bx::Value, Bx::Value) { - debug!("cast_to_dyn_star: {:?} => {:?}", src_ty_and_layout.ty, dst_ty); - assert!( - matches!(dst_ty.kind(), ty::Dynamic(_, _, ty::DynStar)), - "destination type must be a dyn*" - ); - let src = match bx.cx().type_kind(bx.cx().backend_type(src_ty_and_layout)) { - TypeKind::Pointer => src, - TypeKind::Integer => bx.inttoptr(src, bx.type_ptr()), - // FIXME(dyn-star): We probably have to do a bitcast first, then inttoptr. - kind => bug!("unexpected TypeKind for left-hand side of `dyn*` cast: {kind:?}"), - }; - (src, unsized_info(bx, src_ty_and_layout.ty, dst_ty, old_info)) -} - /// Coerces `src`, which is a reference to a value of type `src_ty`, /// to a value of type `dst_ty`, and stores the result in `dst`. pub(crate) fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 1d5fbfc0896..bde63fd501a 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -628,50 +628,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { virtual_drop, ) } - ty::Dynamic(_, _, ty::DynStar) => { - // IN THIS ARM, WE HAVE: - // ty = *mut (dyn* Trait) - // which is: *mut exists<T: sizeof(T) == sizeof(usize)> (T, Vtable<T: Trait>) - // - // args = [ * ] - // | - // v - // ( Data, Vtable ) - // | - // v - // /-------\ - // | ... | - // \-------/ - // - // - // WE CAN CONVERT THIS INTO THE ABOVE LOGIC BY DOING - // - // data = &(*args[0]).0 // gives a pointer to Data above (really the same pointer) - // vtable = (*args[0]).1 // loads the vtable out - // (data, vtable) // an equivalent Rust `*mut dyn Trait` - // - // SO THEN WE CAN USE THE ABOVE CODE. - let virtual_drop = Instance { - def: ty::InstanceKind::Virtual(drop_fn.def_id(), 0), // idx 0: the drop function - args: drop_fn.args, - }; - debug!("ty = {:?}", ty); - debug!("drop_fn = {:?}", drop_fn); - debug!("args = {:?}", args); - let fn_abi = bx.fn_abi_of_instance(virtual_drop, ty::List::empty()); - let meta_ptr = place.project_field(bx, 1); - let meta = bx.load_operand(meta_ptr); - // Truncate vtable off of args list - args = &args[..1]; - debug!("args' = {:?}", args); - ( - true, - meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE) - .get_optional_fn(bx, meta.immediate(), ty, fn_abi), - fn_abi, - virtual_drop, - ) - } _ => ( false, bx.get_fn_addr(drop_fn), @@ -1108,33 +1064,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { llargs.push(data_ptr); continue; } - Immediate(_) => { - // See comment above explaining why we peel these newtypes - while !op.layout.ty.is_raw_ptr() && !op.layout.ty.is_ref() { - let (idx, _) = op.layout.non_1zst_field(bx).expect( - "not exactly one non-1-ZST field in a `DispatchFromDyn` type", - ); - op = op.extract_field(self, bx, idx.as_usize()); - } - - // Make sure that we've actually unwrapped the rcvr down - // to a pointer or ref to `dyn* Trait`. - if !op.layout.ty.builtin_deref(true).unwrap().is_dyn_star() { - span_bug!(fn_span, "can't codegen a virtual call on {:#?}", op); - } - let place = op.deref(bx.cx()); - let data_place = place.project_field(bx, 0); - let meta_place = place.project_field(bx, 1); - let meta = bx.load_operand(meta_place); - llfn = Some(meth::VirtualIndex::from_index(idx).get_fn( - bx, - meta.immediate(), - op.layout.ty, - fn_abi, - )); - llargs.push(data_place.val.llval); - continue; - } _ => { span_bug!(fn_span, "can't codegen a virtual call on {:#?}", op); } diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs index db5ac6a514f..7ef04213d32 100644 --- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs +++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs @@ -468,12 +468,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { bug!("unexpected non-pair operand"); } } - mir::CastKind::PointerCoercion(PointerCoercion::DynStar, _) => { - let (lldata, llextra) = operand.val.pointer_parts(); - let (lldata, llextra) = - base::cast_to_dyn_star(bx, lldata, operand.layout, cast.ty, llextra); - OperandValue::Pair(lldata, llextra) - } | mir::CastKind::IntToInt | mir::CastKind::FloatToInt | mir::CastKind::FloatToFloat diff --git a/compiler/rustc_const_eval/src/check_consts/check.rs b/compiler/rustc_const_eval/src/check_consts/check.rs index c1d91f98957..0eb6f28bdb3 100644 --- a/compiler/rustc_const_eval/src/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/check_consts/check.rs @@ -638,14 +638,6 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { // These are all okay; they only change the type, not the data. } - Rvalue::Cast( - CastKind::PointerCoercion(PointerCoercion::Unsize | PointerCoercion::DynStar, _), - _, - _, - ) => { - // Unsizing and `dyn*` coercions are implemented for CTFE. - } - Rvalue::Cast(CastKind::PointerExposeProvenance, _, _) => { self.check_op(ops::RawPtrToIntCast); } diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs index 79c14b204e3..ebaa5a97a4a 100644 --- a/compiler/rustc_const_eval/src/interpret/call.rs +++ b/compiler/rustc_const_eval/src/interpret/call.rs @@ -643,13 +643,6 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { break self.ref_to_mplace(&val)?; } ty::Dynamic(.., ty::Dyn) => break receiver.assert_mem_place(), // no immediate unsized values - ty::Dynamic(.., ty::DynStar) => { - // Not clear how to handle this, so far we assume the receiver is always a pointer. - span_bug!( - self.cur_span(), - "by-value calls on a `dyn*`... are those a thing?" - ); - } _ => { // Not there yet, search for the only non-ZST field. // (The rules for `DispatchFromDyn` ensure there's exactly one such field.) @@ -662,39 +655,23 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { }; // Obtain the underlying trait we are working on, and the adjusted receiver argument. - let (trait_, dyn_ty, adjusted_recv) = if let ty::Dynamic(data, _, ty::DynStar) = - receiver_place.layout.ty.kind() - { - let recv = self.unpack_dyn_star(&receiver_place, data)?; - - (data.principal(), recv.layout.ty, recv.ptr()) - } else { - // Doesn't have to be a `dyn Trait`, but the unsized tail must be `dyn Trait`. - // (For that reason we also cannot use `unpack_dyn_trait`.) - let receiver_tail = - self.tcx.struct_tail_for_codegen(receiver_place.layout.ty, self.typing_env); - let ty::Dynamic(receiver_trait, _, ty::Dyn) = receiver_tail.kind() else { - span_bug!( - self.cur_span(), - "dynamic call on non-`dyn` type {}", - receiver_tail - ) - }; - assert!(receiver_place.layout.is_unsized()); - - // Get the required information from the vtable. - let vptr = receiver_place.meta().unwrap_meta().to_pointer(self)?; - let dyn_ty = self.get_ptr_vtable_ty(vptr, Some(receiver_trait))?; - - // It might be surprising that we use a pointer as the receiver even if this - // is a by-val case; this works because by-val passing of an unsized `dyn - // Trait` to a function is actually desugared to a pointer. - (receiver_trait.principal(), dyn_ty, receiver_place.ptr()) + // Doesn't have to be a `dyn Trait`, but the unsized tail must be `dyn Trait`. + // (For that reason we also cannot use `unpack_dyn_trait`.) + let receiver_tail = + self.tcx.struct_tail_for_codegen(receiver_place.layout.ty, self.typing_env); + let ty::Dynamic(receiver_trait, _, ty::Dyn) = receiver_tail.kind() else { + span_bug!(self.cur_span(), "dynamic call on non-`dyn` type {}", receiver_tail) }; + assert!(receiver_place.layout.is_unsized()); + + // Get the required information from the vtable. + let vptr = receiver_place.meta().unwrap_meta().to_pointer(self)?; + let dyn_ty = self.get_ptr_vtable_ty(vptr, Some(receiver_trait))?; + let adjusted_recv = receiver_place.ptr(); // Now determine the actual method to call. Usually we use the easy way of just // looking up the method at index `idx`. - let vtable_entries = self.vtable_entries(trait_, dyn_ty); + let vtable_entries = self.vtable_entries(receiver_trait.principal(), dyn_ty); let Some(ty::VtblEntry::Method(fn_inst)) = vtable_entries.get(idx).copied() else { // FIXME(fee1-dead) these could be variants of the UB info enum instead of this throw_ub_custom!(fluent::const_eval_dyn_call_not_a_method); @@ -830,10 +807,6 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { // Dropping a trait object. Need to find actual drop fn. self.unpack_dyn_trait(&place, data)? } - ty::Dynamic(data, _, ty::DynStar) => { - // Dropping a `dyn*`. Need to find actual drop fn. - self.unpack_dyn_star(&place, data)? - } _ => { debug_assert_eq!( instance, diff --git a/compiler/rustc_const_eval/src/interpret/cast.rs b/compiler/rustc_const_eval/src/interpret/cast.rs index 1036935bb10..7a73d70fc85 100644 --- a/compiler/rustc_const_eval/src/interpret/cast.rs +++ b/compiler/rustc_const_eval/src/interpret/cast.rs @@ -126,20 +126,6 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { } } - CastKind::PointerCoercion(PointerCoercion::DynStar, _) => { - if let ty::Dynamic(data, _, ty::DynStar) = cast_ty.kind() { - // Initial cast from sized to dyn trait - let vtable = self.get_vtable_ptr(src.layout.ty, data)?; - let vtable = Scalar::from_maybe_pointer(vtable, self); - let data = self.read_immediate(src)?.to_scalar(); - let _assert_pointer_like = data.to_pointer(self)?; - let val = Immediate::ScalarPair(data, vtable); - self.write_immediate(val, dest)?; - } else { - bug!() - } - } - CastKind::Transmute => { assert!(src.layout.is_sized()); assert!(dest.layout.is_sized()); diff --git a/compiler/rustc_const_eval/src/interpret/stack.rs b/compiler/rustc_const_eval/src/interpret/stack.rs index 3361a586b8e..543d68d7f45 100644 --- a/compiler/rustc_const_eval/src/interpret/stack.rs +++ b/compiler/rustc_const_eval/src/interpret/stack.rs @@ -499,8 +499,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never - | ty::Error(_) - | ty::Dynamic(_, _, ty::DynStar) => true, + | ty::Error(_) => true, ty::Str | ty::Slice(_) | ty::Dynamic(_, _, ty::Dyn) | ty::Foreign(..) => false, diff --git a/compiler/rustc_const_eval/src/interpret/traits.rs b/compiler/rustc_const_eval/src/interpret/traits.rs index 8b634955bb7..e4b5c82853a 100644 --- a/compiler/rustc_const_eval/src/interpret/traits.rs +++ b/compiler/rustc_const_eval/src/interpret/traits.rs @@ -1,4 +1,4 @@ -use rustc_abi::{Align, FieldIdx, Size}; +use rustc_abi::{Align, Size}; use rustc_middle::mir::interpret::{InterpResult, Pointer}; use rustc_middle::ty::{self, ExistentialPredicateStableCmpExt, Ty, TyCtxt, VtblEntry}; use tracing::trace; @@ -125,24 +125,4 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { )?; interp_ok(mplace) } - - /// Turn a `dyn* Trait` type into an value with the actual dynamic type. - pub(super) fn unpack_dyn_star<P: Projectable<'tcx, M::Provenance>>( - &self, - val: &P, - expected_trait: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>, - ) -> InterpResult<'tcx, P> { - assert!( - matches!(val.layout().ty.kind(), ty::Dynamic(_, _, ty::DynStar)), - "`unpack_dyn_star` only makes sense on `dyn*` types" - ); - let data = self.project_field(val, FieldIdx::ZERO)?; - let vtable = self.project_field(val, FieldIdx::ONE)?; - let vtable = self.read_pointer(&vtable.to_op(self)?)?; - let ty = self.get_ptr_vtable_ty(vtable, Some(expected_trait))?; - // `data` is already the right thing but has the wrong type. So we transmute it. - let layout = self.layout_of(ty)?; - let data = data.transmute(layout, self)?; - interp_ok(data) - } } diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs index 72680019380..e26cf0a4900 100644 --- a/compiler/rustc_const_eval/src/interpret/validity.rs +++ b/compiler/rustc_const_eval/src/interpret/validity.rs @@ -358,9 +358,6 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { // arrays/slices ty::Array(..) | ty::Slice(..) => PathElem::ArrayElem(field), - // dyn* vtables - ty::Dynamic(_, _, ty::DynKind::DynStar) if field == 1 => PathElem::Vtable, - // dyn traits ty::Dynamic(..) => { assert_eq!(field, 0); diff --git a/compiler/rustc_const_eval/src/interpret/visitor.rs b/compiler/rustc_const_eval/src/interpret/visitor.rs index d5970b69baf..a27b6646131 100644 --- a/compiler/rustc_const_eval/src/interpret/visitor.rs +++ b/compiler/rustc_const_eval/src/interpret/visitor.rs @@ -101,26 +101,6 @@ pub trait ValueVisitor<'tcx, M: Machine<'tcx>>: Sized { // recurse with the inner type return self.visit_field(v, 0, &inner_mplace.into()); } - ty::Dynamic(data, _, ty::DynStar) => { - // DynStar types. Very different from a dyn type (but strangely part of the - // same variant in `TyKind`): These are pairs where the 2nd component is the - // vtable, and the first component is the data (which must be ptr-sized). - - // First make sure the vtable can be read at its type. - // The type of this vtable is fake, it claims to be a reference to some actual memory but that isn't true. - // So we transmute it to a raw pointer. - let raw_ptr_ty = Ty::new_mut_ptr(*self.ecx().tcx, self.ecx().tcx.types.unit); - let raw_ptr_ty = self.ecx().layout_of(raw_ptr_ty)?; - let vtable_field = self - .ecx() - .project_field(v, FieldIdx::ONE)? - .transmute(raw_ptr_ty, self.ecx())?; - self.visit_field(v, 1, &vtable_field)?; - - // Then unpack the first field, and continue. - let data = self.ecx().unpack_dyn_star(v, data)?; - return self.visit_field(v, 0, &data); - } // Slices do not need special handling here: they have `Array` field // placement with length 0, so we enter the `Array` case below which // indirectly uses the metadata to determine the actual length. diff --git a/compiler/rustc_feature/src/removed.rs b/compiler/rustc_feature/src/removed.rs index a855e4c1b0e..10fcf744fbc 100644 --- a/compiler/rustc_feature/src/removed.rs +++ b/compiler/rustc_feature/src/removed.rs @@ -123,6 +123,9 @@ declare_features! ( /// [^1]: Formerly known as "object safe". (removed, dyn_compatible_for_dispatch, "1.87.0", Some(43561), Some("removed, not used heavily and represented additional complexity in dyn compatibility"), 136522), + /// Allows `dyn* Trait` objects. + (removed, dyn_star, "1.65.0", Some(102425), + Some("removed as it was no longer necessary for AFIDT (async fn in dyn trait) support")), /// Uses generic effect parameters for [const] bounds (removed, effects, "1.84.0", Some(102090), Some("removed, redundant with `#![feature(const_trait_impl)]`"), 132479), diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs index 719ba597da1..ea6c38a65c1 100644 --- a/compiler/rustc_feature/src/unstable.rs +++ b/compiler/rustc_feature/src/unstable.rs @@ -481,8 +481,6 @@ declare_features! ( (unstable, doc_cfg_hide, "1.57.0", Some(43781)), /// Allows `#[doc(masked)]`. (unstable, doc_masked, "1.21.0", Some(44027)), - /// Allows `dyn* Trait` objects. - (incomplete, dyn_star, "1.65.0", Some(102425)), /// Allows the .use postfix syntax `x.use` and use closures `use |x| { ... }` (incomplete, ergonomic_clones, "1.87.0", Some(132290)), /// Allows exhaustive pattern matching on types that contain uninhabited types. diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs index 0170a880454..c90cd93ff07 100644 --- a/compiler/rustc_hir/src/hir.rs +++ b/compiler/rustc_hir/src/hir.rs @@ -956,7 +956,7 @@ impl<'hir> Generics<'hir> { && let Some(ret_ty) = segment.args().paren_sugar_output() && let ret_ty = ret_ty.peel_refs() && let TyKind::TraitObject(_, tagged_ptr) = ret_ty.kind - && let TraitObjectSyntax::Dyn | TraitObjectSyntax::DynStar = tagged_ptr.tag() + && let TraitObjectSyntax::Dyn = tagged_ptr.tag() && ret_ty.span.can_be_used_for_suggestions() { Some(ret_ty.span) diff --git a/compiler/rustc_hir/src/hir/tests.rs b/compiler/rustc_hir/src/hir/tests.rs index 1fd793bc161..4f9609fd360 100644 --- a/compiler/rustc_hir/src/hir/tests.rs +++ b/compiler/rustc_hir/src/hir/tests.rs @@ -45,7 +45,6 @@ define_tests! { #[test] fn trait_object_roundtrips() { trait_object_roundtrips_impl(TraitObjectSyntax::Dyn); - trait_object_roundtrips_impl(TraitObjectSyntax::DynStar); trait_object_roundtrips_impl(TraitObjectSyntax::None); } diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index 55bf2ab6b50..6b2854d96af 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -2433,7 +2433,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } else { let repr = match repr { TraitObjectSyntax::Dyn | TraitObjectSyntax::None => ty::Dyn, - TraitObjectSyntax::DynStar => ty::DynStar, }; self.lower_trait_object_ty(hir_ty.span, hir_ty.hir_id, bounds, lifetime, repr) } diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs index e00c22c47aa..c523a03e012 100644 --- a/compiler/rustc_hir_pretty/src/lib.rs +++ b/compiler/rustc_hir_pretty/src/lib.rs @@ -420,7 +420,6 @@ impl<'a> State<'a> { let syntax = lifetime.tag(); match syntax { ast::TraitObjectSyntax::Dyn => self.word_nbsp("dyn"), - ast::TraitObjectSyntax::DynStar => self.word_nbsp("dyn*"), ast::TraitObjectSyntax::None => {} } let mut first = true; diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs index 6f8abc1e67d..3eeb0eac023 100644 --- a/compiler/rustc_hir_typeck/src/cast.rs +++ b/compiler/rustc_hir_typeck/src/cast.rs @@ -143,7 +143,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { | ty::Coroutine(..) | ty::Adt(..) | ty::Never - | ty::Dynamic(_, _, ty::DynStar) | ty::Error(_) => { let guar = self .dcx() @@ -734,14 +733,6 @@ impl<'a, 'tcx> CastCheck<'tcx> { use rustc_middle::ty::cast::CastTy::*; use rustc_middle::ty::cast::IntTy::*; - if self.cast_ty.is_dyn_star() { - // This coercion will fail if the feature is not enabled, OR - // if the coercion is (currently) illegal (e.g. `dyn* Foo + Send` - // to `dyn* Foo`). Report "casting is invalid" rather than - // "non-primitive cast". - return Err(CastError::IllegalCast); - } - let (t_from, t_cast) = match (CastTy::from_ty(self.expr_ty), CastTy::from_ty(self.cast_ty)) { (Some(t_from), Some(t_cast)) => (t_from, t_cast), diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs index 57d3c5da873..3ca04ba330b 100644 --- a/compiler/rustc_hir_typeck/src/coercion.rs +++ b/compiler/rustc_hir_typeck/src/coercion.rs @@ -231,9 +231,6 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> { ty::Ref(r_b, _, mutbl_b) => { return self.coerce_borrowed_pointer(a, b, r_b, mutbl_b); } - ty::Dynamic(predicates, region, ty::DynStar) if self.tcx.features().dyn_star() => { - return self.coerce_dyn_star(a, b, predicates, region); - } ty::Adt(pin, _) if self.tcx.features().pin_ergonomics() && self.tcx.is_lang_item(pin.did(), hir::LangItem::Pin) => @@ -773,71 +770,6 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> { Ok(coercion) } - fn coerce_dyn_star( - &self, - a: Ty<'tcx>, - b: Ty<'tcx>, - predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>, - b_region: ty::Region<'tcx>, - ) -> CoerceResult<'tcx> { - if !self.tcx.features().dyn_star() { - return Err(TypeError::Mismatch); - } - - // FIXME(dyn_star): We should probably allow things like casting from - // `dyn* Foo + Send` to `dyn* Foo`. - if let ty::Dynamic(a_data, _, ty::DynStar) = a.kind() - && let ty::Dynamic(b_data, _, ty::DynStar) = b.kind() - && a_data.principal_def_id() == b_data.principal_def_id() - { - return self.unify(a, b); - } - - // Check the obligations of the cast -- for example, when casting - // `usize` to `dyn* Clone + 'static`: - let obligations = predicates - .iter() - .map(|predicate| { - // For each existential predicate (e.g., `?Self: Clone`) instantiate - // the type of the expression (e.g., `usize` in our example above) - // and then require that the resulting predicate (e.g., `usize: Clone`) - // holds (it does). - let predicate = predicate.with_self_ty(self.tcx, a); - Obligation::new(self.tcx, self.cause.clone(), self.param_env, predicate) - }) - .chain([ - // Enforce the region bound (e.g., `usize: 'static`, in our example). - Obligation::new( - self.tcx, - self.cause.clone(), - self.param_env, - ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::TypeOutlives( - ty::OutlivesPredicate(a, b_region), - ))), - ), - // Enforce that the type is `usize`/pointer-sized. - Obligation::new( - self.tcx, - self.cause.clone(), - self.param_env, - ty::TraitRef::new( - self.tcx, - self.tcx.require_lang_item(hir::LangItem::PointerLike, self.cause.span), - [a], - ), - ), - ]) - .collect(); - - Ok(InferOk { - value: ( - vec![Adjustment { kind: Adjust::Pointer(PointerCoercion::DynStar), target: b }], - b, - ), - obligations, - }) - } - /// Applies reborrowing for `Pin` /// /// We currently only support reborrowing `Pin<&mut T>` as `Pin<&mut T>`. This is accomplished diff --git a/compiler/rustc_middle/src/ty/adjustment.rs b/compiler/rustc_middle/src/ty/adjustment.rs index 3bacdfe5ac8..74573455f53 100644 --- a/compiler/rustc_middle/src/ty/adjustment.rs +++ b/compiler/rustc_middle/src/ty/adjustment.rs @@ -36,9 +36,6 @@ pub enum PointerCoercion { /// type. Codegen backends and miri figure out what has to be done /// based on the precise source/target type at hand. Unsize, - - /// Go from a pointer-like type to a `dyn*` object. - DynStar, } /// Represents coercing a value to a different type of value. diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs index 90b832df281..09379d9d805 100644 --- a/compiler/rustc_middle/src/ty/layout.rs +++ b/compiler/rustc_middle/src/ty/layout.rs @@ -946,21 +946,6 @@ where } } - ty::Dynamic(_, _, ty::DynStar) => { - if i == 0 { - TyMaybeWithLayout::Ty(Ty::new_mut_ptr(tcx, tcx.types.unit)) - } else if i == 1 { - // FIXME(dyn-star) same FIXME as above applies here too - TyMaybeWithLayout::Ty(Ty::new_imm_ref( - tcx, - tcx.lifetimes.re_static, - Ty::new_array(tcx, tcx.types.usize, 3), - )) - } else { - bug!("no field {i} on dyn*") - } - } - ty::Alias(..) | ty::Bound(..) | ty::Placeholder(..) diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index bee490b3648..b4c4f48a0a6 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -810,7 +810,6 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write { } match repr { ty::Dyn => p!("dyn "), - ty::DynStar => p!("dyn* "), } p!(print(data)); if print_r { diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index 3971ac13bbe..399a6d6ebc5 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -1322,11 +1322,6 @@ impl<'tcx> Ty<'tcx> { } #[inline] - pub fn is_dyn_star(self) -> bool { - matches!(self.kind(), Dynamic(_, _, ty::DynStar)) - } - - #[inline] pub fn is_enum(self) -> bool { matches!(self.kind(), Adt(adt_def, _) if adt_def.is_enum()) } @@ -1629,8 +1624,6 @@ impl<'tcx> Ty<'tcx> { | ty::Error(_) // Extern types have metadata = (). | ty::Foreign(..) - // `dyn*` has metadata = (). - | ty::Dynamic(_, _, ty::DynStar) // If returned by `struct_tail_raw` this is a unit struct // without any fields, or not a struct, and therefore is Sized. | ty::Adt(..) @@ -1820,8 +1813,7 @@ impl<'tcx> Ty<'tcx> { | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never - | ty::Error(_) - | ty::Dynamic(_, _, ty::DynStar) => true, + | ty::Error(_) => true, ty::Str | ty::Slice(_) | ty::Dynamic(_, _, ty::Dyn) => match sizedness { SizedTraitKind::Sized => false, diff --git a/compiler/rustc_mir_transform/src/mentioned_items.rs b/compiler/rustc_mir_transform/src/mentioned_items.rs index 9fd8d81d64a..f011d394f61 100644 --- a/compiler/rustc_mir_transform/src/mentioned_items.rs +++ b/compiler/rustc_mir_transform/src/mentioned_items.rs @@ -74,8 +74,7 @@ impl<'tcx> Visitor<'tcx> for MentionedItemsVisitor<'_, 'tcx> { match *rvalue { // We need to detect unsizing casts that required vtables. mir::Rvalue::Cast( - mir::CastKind::PointerCoercion(PointerCoercion::Unsize, _) - | mir::CastKind::PointerCoercion(PointerCoercion::DynStar, _), + mir::CastKind::PointerCoercion(PointerCoercion::Unsize, _), ref operand, target_ty, ) => { diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs index 7dcdd7999f2..cbb9bbfd12f 100644 --- a/compiler/rustc_mir_transform/src/validate.rs +++ b/compiler/rustc_mir_transform/src/validate.rs @@ -1260,9 +1260,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { self.fail(location, format!("Unsize coercion, but `{op_ty}` isn't coercible to `{target_type}`")); } } - CastKind::PointerCoercion(PointerCoercion::DynStar, _) => { - // FIXME(dyn-star): make sure nothing needs to be done here. - } CastKind::IntToInt | CastKind::IntToFloat => { let input_valid = op_ty.is_integral() || op_ty.is_char() || op_ty.is_bool(); let target_valid = target_type.is_numeric() || target_type.is_char(); diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 798f4da9b3b..91e371d697d 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -694,8 +694,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { // have to instantiate all methods of the trait being cast to, so we // can build the appropriate vtable. mir::Rvalue::Cast( - mir::CastKind::PointerCoercion(PointerCoercion::Unsize, _) - | mir::CastKind::PointerCoercion(PointerCoercion::DynStar, _), + mir::CastKind::PointerCoercion(PointerCoercion::Unsize, _), ref operand, target_ty, ) => { @@ -710,9 +709,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { // This could also be a different Unsize instruction, like // from a fixed sized array to a slice. But we are only // interested in things that produce a vtable. - if (target_ty.is_trait() && !source_ty.is_trait()) - || (target_ty.is_dyn_star() && !source_ty.is_dyn_star()) - { + if target_ty.is_trait() && !source_ty.is_trait() { create_mono_items_for_vtable_methods( self.tcx, target_ty, @@ -1109,14 +1106,6 @@ fn find_tails_for_unsizing<'tcx>( find_tails_for_unsizing(tcx, source_field, target_field) } - // `T` as `dyn* Trait` unsizes *directly*. - // - // FIXME(dyn_star): This case is a bit awkward, b/c we're not really computing - // a tail here. We probably should handle this separately in the *caller* of - // this function, rather than returning something that is semantically different - // than what we return above. - (_, &ty::Dynamic(_, _, ty::DynStar)) => (source_ty, target_ty), - _ => bug!( "find_vtable_types_for_unsizing: invalid coercion {:?} -> {:?}", source_ty, @@ -1344,9 +1333,7 @@ fn visit_mentioned_item<'tcx>( // This could also be a different Unsize instruction, like // from a fixed sized array to a slice. But we are only // interested in things that produce a vtable. - if (target_ty.is_trait() && !source_ty.is_trait()) - || (target_ty.is_dyn_star() && !source_ty.is_dyn_star()) - { + if target_ty.is_trait() && !source_ty.is_trait() { create_mono_items_for_vtable_methods(tcx, target_ty, source_ty, span, output); } } diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs index 73bb1508de9..c0bebdf6fb6 100644 --- a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs +++ b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs @@ -135,7 +135,6 @@ where | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never - | ty::Dynamic(_, _, ty::DynStar) | ty::Error(_) => Ok(ty::Binder::dummy(vec![])), // impl {Meta,}Sized for str, [T], dyn Trait diff --git a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs index edb354b4a84..1e0a90eb2ee 100644 --- a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs +++ b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs @@ -657,8 +657,7 @@ where | ty::Coroutine(..) | ty::CoroutineWitness(..) | ty::Never - | ty::Foreign(..) - | ty::Dynamic(_, _, ty::DynStar) => Ty::new_unit(cx), + | ty::Foreign(..) => Ty::new_unit(cx), ty::Error(e) => Ty::new_error(cx, e), diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs index d874a071cee..8221c709027 100644 --- a/compiler/rustc_parse/src/parser/ty.rs +++ b/compiler/rustc_parse/src/parser/ty.rs @@ -796,16 +796,10 @@ impl<'a> Parser<'a> { /// /// Note that this does *not* parse bare trait objects. fn parse_dyn_ty(&mut self, impl_dyn_multi: &mut bool) -> PResult<'a, TyKind> { - let lo = self.token.span; self.bump(); // `dyn` - // parse dyn* types - let syntax = if self.eat(exp!(Star)) { - self.psess.gated_spans.gate(sym::dyn_star, lo.to(self.prev_token.span)); - TraitObjectSyntax::DynStar - } else { - TraitObjectSyntax::Dyn - }; + // We used to parse `*` for `dyn*` here. + let syntax = TraitObjectSyntax::Dyn; // Always parse bounds greedily for better error recovery. let bounds = self.parse_generic_bounds()?; diff --git a/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs b/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs index 9d1d3412f8d..f4a14b36ce5 100644 --- a/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs +++ b/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs @@ -631,7 +631,6 @@ pub(crate) fn encode_ty<'tcx>( // vendor extended type. let mut s = String::from(match kind { ty::Dyn => "u3dynI", - ty::DynStar => "u7dynstarI", }); s.push_str(&encode_predicates(tcx, predicates, dict, options)); s.push_str(&encode_region(*region, dict)); diff --git a/compiler/rustc_smir/src/rustc_internal/internal.rs b/compiler/rustc_smir/src/rustc_internal/internal.rs index 24351eee1c4..f878b6e6b71 100644 --- a/compiler/rustc_smir/src/rustc_internal/internal.rs +++ b/compiler/rustc_smir/src/rustc_internal/internal.rs @@ -369,7 +369,6 @@ impl RustcInternal for DynKind { fn internal<'tcx>(&self, _tables: &mut Tables<'_>, _tcx: TyCtxt<'tcx>) -> Self::T<'tcx> { match self { DynKind::Dyn => rustc_ty::DynKind::Dyn, - DynKind::DynStar => rustc_ty::DynKind::DynStar, } } } diff --git a/compiler/rustc_smir/src/rustc_smir/convert/mir.rs b/compiler/rustc_smir/src/rustc_smir/convert/mir.rs index 85e71ed2c25..daea4acc36c 100644 --- a/compiler/rustc_smir/src/rustc_smir/convert/mir.rs +++ b/compiler/rustc_smir/src/rustc_smir/convert/mir.rs @@ -301,11 +301,9 @@ impl<'tcx> Stable<'tcx> for mir::CastKind { type T = stable_mir::mir::CastKind; fn stable(&self, tables: &mut Tables<'_>) -> Self::T { use rustc_middle::mir::CastKind::*; - use rustc_middle::ty::adjustment::PointerCoercion; match self { PointerExposeProvenance => stable_mir::mir::CastKind::PointerExposeAddress, PointerWithExposedProvenance => stable_mir::mir::CastKind::PointerWithExposedProvenance, - PointerCoercion(PointerCoercion::DynStar, _) => stable_mir::mir::CastKind::DynStar, PointerCoercion(c, _) => stable_mir::mir::CastKind::PointerCoercion(c.stable(tables)), IntToInt => stable_mir::mir::CastKind::IntToInt, FloatToInt => stable_mir::mir::CastKind::FloatToInt, diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs index 7abec488151..ff0b8e833dc 100644 --- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs +++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs @@ -43,7 +43,6 @@ impl<'tcx> Stable<'tcx> for ty::DynKind { fn stable(&self, _: &mut Tables<'_>) -> Self::T { match self { ty::Dyn => stable_mir::ty::DynKind::Dyn, - ty::DynStar => stable_mir::ty::DynKind::DynStar, } } } @@ -120,7 +119,6 @@ impl<'tcx> Stable<'tcx> for ty::adjustment::PointerCoercion { } PointerCoercion::ArrayToPointer => stable_mir::mir::PointerCoercion::ArrayToPointer, PointerCoercion::Unsize => stable_mir::mir::PointerCoercion::Unsize, - PointerCoercion::DynStar => unreachable!("represented as `CastKind::DynStar` in smir"), } } } diff --git a/compiler/rustc_smir/src/stable_mir/mir/body.rs b/compiler/rustc_smir/src/stable_mir/mir/body.rs index e4b7659ce7f..90d4a06b177 100644 --- a/compiler/rustc_smir/src/stable_mir/mir/body.rs +++ b/compiler/rustc_smir/src/stable_mir/mir/body.rs @@ -1025,8 +1025,6 @@ pub enum CastKind { PointerExposeAddress, PointerWithExposedProvenance, PointerCoercion(PointerCoercion), - // FIXME(smir-rename): change this to PointerCoercion(DynStar) - DynStar, IntToInt, FloatToInt, FloatToFloat, diff --git a/compiler/rustc_smir/src/stable_mir/ty.rs b/compiler/rustc_smir/src/stable_mir/ty.rs index 7f6237e7062..4ea2bb04c5d 100644 --- a/compiler/rustc_smir/src/stable_mir/ty.rs +++ b/compiler/rustc_smir/src/stable_mir/ty.rs @@ -1205,7 +1205,6 @@ pub enum BoundRegionKind { #[derive(Clone, Debug, Eq, PartialEq, Serialize)] pub enum DynKind { Dyn, - DynStar, } #[derive(Clone, Debug, Eq, PartialEq, Serialize)] diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs index 1db8ad72b32..fe0f8e6113e 100644 --- a/compiler/rustc_symbol_mangling/src/v0.rs +++ b/compiler/rustc_symbol_mangling/src/v0.rs @@ -576,8 +576,6 @@ impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> { ty::Dynamic(predicates, r, kind) => { self.push(match kind { ty::Dyn => "D", - // FIXME(dyn-star): need to update v0 mangling docs - ty::DynStar => "D*", }); self.print_dyn_existential(predicates)?; r.print(self)?; diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs index 0a4a9144c94..aea42df4dfd 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs @@ -353,26 +353,6 @@ impl<T> Trait<T> for X { )); } } - (ty::Dynamic(t, _, ty::DynKind::DynStar), _) - if let Some(def_id) = t.principal_def_id() => - { - let mut has_matching_impl = false; - tcx.for_each_relevant_impl(def_id, values.found, |did| { - if DeepRejectCtxt::relate_rigid_infer(tcx) - .types_may_unify(values.found, tcx.type_of(did).skip_binder()) - { - has_matching_impl = true; - } - }); - if has_matching_impl { - let trait_name = tcx.item_name(def_id); - diag.help(format!( - "`{}` implements `{trait_name}`, `#[feature(dyn_star)]` is likely \ - not enabled; that feature it is currently incomplete", - values.found, - )); - } - } (_, ty::Alias(ty::Opaque, opaque_ty)) | (ty::Alias(ty::Opaque, opaque_ty), _) => { if opaque_ty.def_id.is_local() diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 316b4dfc15f..af3641c22ed 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -2129,7 +2129,6 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never - | ty::Dynamic(_, _, ty::DynStar) | ty::Error(_) => { // safe for everything Where(ty::Binder::dummy(Vec::new())) diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs index d5222822461..a225b712d4b 100644 --- a/compiler/rustc_ty_utils/src/layout.rs +++ b/compiler/rustc_ty_utils/src/layout.rs @@ -449,14 +449,6 @@ fn layout_of_uncached<'tcx>( tcx.mk_layout(LayoutData::scalar_pair(cx, data_ptr, metadata)) } - ty::Dynamic(_, _, ty::DynStar) => { - let mut data = scalar_unit(Pointer(AddressSpace::DATA)); - data.valid_range_mut().start = 0; - let mut vtable = scalar_unit(Pointer(AddressSpace::DATA)); - vtable.valid_range_mut().start = 1; - tcx.mk_layout(LayoutData::scalar_pair(cx, data, vtable)) - } - // Arrays and slices. ty::Array(element, count) => { let count = extract_const_value(cx, ty, count)? diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs index 553f5e0e1b5..f8d793464a9 100644 --- a/compiler/rustc_ty_utils/src/ty.rs +++ b/compiler/rustc_ty_utils/src/ty.rs @@ -38,8 +38,7 @@ fn sizedness_constraint_for_ty<'tcx>( | ty::CoroutineClosure(..) | ty::Coroutine(..) | ty::CoroutineWitness(..) - | ty::Never - | ty::Dynamic(_, _, ty::DynStar) => None, + | ty::Never => None, ty::Str | ty::Slice(..) | ty::Dynamic(_, _, ty::Dyn) => match sizedness { // Never `Sized` @@ -383,8 +382,7 @@ fn impl_self_is_guaranteed_unsized<'tcx>(tcx: TyCtxt<'tcx>, impl_def_id: DefId) | ty::Bound(_, _) | ty::Placeholder(_) | ty::Infer(_) - | ty::Error(_) - | ty::Dynamic(_, _, ty::DynStar) => false, + | ty::Error(_) => false, } } diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs index 272fca5b026..2754d40fd36 100644 --- a/compiler/rustc_type_ir/src/inherent.rs +++ b/compiler/rustc_type_ir/src/inherent.rs @@ -183,8 +183,7 @@ pub trait Ty<I: Interner<Ty = Self>>: | ty::Bound(_, _) | ty::Placeholder(_) | ty::Infer(_) - | ty::Error(_) - | ty::Dynamic(_, _, ty::DynStar) => false, + | ty::Error(_) => false, } } } diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs index 9669772d1a6..db6fbefcf05 100644 --- a/compiler/rustc_type_ir/src/ty_kind.rs +++ b/compiler/rustc_type_ir/src/ty_kind.rs @@ -20,6 +20,9 @@ use crate::{self as ty, DebruijnIndex, Interner}; mod closure; /// Specifies how a trait object is represented. +/// +/// This used to have a variant `DynStar`, but that variant has been removed, +/// and it's likely this whole enum will be removed soon. #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] #[cfg_attr( feature = "nightly", @@ -28,13 +31,6 @@ mod closure; pub enum DynKind { /// An unsized `dyn Trait` object Dyn, - /// A sized `dyn* Trait` object - /// - /// These objects are represented as a `(data, vtable)` pair where `data` is a value of some - /// ptr-sized and ptr-aligned dynamically determined type `T` and `vtable` is a pointer to the - /// vtable of `impl T for Trait`. This allows a `dyn*` object to be treated agnostically with - /// respect to whether it points to a `Box<T>`, `Rc<T>`, etc. - DynStar, } #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] @@ -371,7 +367,6 @@ impl<I: Interner> fmt::Debug for TyKind<I> { UnsafeBinder(binder) => write!(f, "{:?}", binder), Dynamic(p, r, repr) => match repr { DynKind::Dyn => write!(f, "dyn {p:?} + {r:?}"), - DynKind::DynStar => write!(f, "dyn* {p:?} + {r:?}"), }, Closure(d, s) => f.debug_tuple("Closure").field(d).field(&s).finish(), CoroutineClosure(d, s) => f.debug_tuple("CoroutineClosure").field(d).field(&s).finish(), |