diff options
| author | bors <bors@rust-lang.org> | 2024-04-23 02:10:23 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2024-04-23 02:10:23 +0000 |
| commit | aca749eefceaed0cda19a7ec5e472fce9387bc00 (patch) | |
| tree | 391e0a9380929d3eec91a04db511437d5d8d95c0 /compiler | |
| parent | 9cf10bcf5b368de79abc24fc4d50a9d85b377ffa (diff) | |
| parent | 67980dd6fb11917d23d01a19c2cf4cfc3978aac8 (diff) | |
| download | rust-aca749eefceaed0cda19a7ec5e472fce9387bc00.tar.gz rust-aca749eefceaed0cda19a7ec5e472fce9387bc00.zip | |
Auto merge of #121801 - zetanumbers:async_drop_glue, r=oli-obk
Add simple async drop glue generation This is a prototype of the async drop glue generation for some simple types. Async drop glue is intended to behave very similar to the regular drop glue except for being asynchronous. Currently it does not execute synchronous drops but only calls user implementations of `AsyncDrop::async_drop` associative function and awaits the returned future. It is not complete as it only recurses into arrays, slices, tuples, and structs and does not have same sensible restrictions as the old `Drop` trait implementation like having the same bounds as the type definition, while code assumes their existence (requires a future work). This current design uses a workaround as it does not create any custom async destructor state machine types for ADTs, but instead uses types defined in the std library called future combinators (deferred_async_drop, chain, ready_unit). Also I recommend reading my [explainer](https://zetanumbers.github.io/book/async-drop-design.html). This is a part of the [MCP: Low level components for async drop](https://github.com/rust-lang/compiler-team/issues/727) work. Feature completeness: - [x] `AsyncDrop` trait - [ ] `async_drop_in_place_raw`/async drop glue generation support for - [x] Trivially destructible types (integers, bools, floats, string slices, pointers, references, etc.) - [x] Arrays and slices (array pointer is unsized into slice pointer) - [x] ADTs (enums, structs, unions) - [x] tuple-like types (tuples, closures) - [ ] Dynamic types (`dyn Trait`, see explainer's [proposed design](https://github.com/zetanumbers/posts/blob/main/async-drop-design.md#async-drop-glue-for-dyn-trait)) - [ ] coroutines (https://github.com/rust-lang/rust/pull/123948) - [x] Async drop glue includes sync drop glue code - [x] Cleanup branch generation for `async_drop_in_place_raw` - [ ] Union rejects non-trivially async destructible fields - [ ] `AsyncDrop` implementation requires same bounds as type definition - [ ] Skip trivially destructible fields (optimization) - [ ] New [`TyKind::AdtAsyncDestructor`](https://github.com/zetanumbers/posts/blob/main/async-drop-design.md#adt-async-destructor-types) and get rid of combinators - [ ] [Synchronously undroppable types](https://github.com/zetanumbers/posts/blob/main/async-drop-design.md#exclusively-async-drop) - [ ] Automatic async drop at the end of the scope in async context
Diffstat (limited to 'compiler')
35 files changed, 1174 insertions, 24 deletions
diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs index b19f52182b6..cce3f0e6f2d 100644 --- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs +++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs @@ -363,6 +363,24 @@ fn exported_symbols_provider_local( }, )); } + MonoItem::Fn(Instance { + def: InstanceDef::AsyncDropGlueCtorShim(def_id, Some(ty)), + args, + }) => { + // A little sanity-check + debug_assert_eq!( + args.non_erasable_generics(tcx, def_id).skip(1).next(), + Some(GenericArgKind::Type(ty)) + ); + symbols.push(( + ExportedSymbol::AsyncDropGlueCtorShim(ty), + SymbolExportInfo { + level: SymbolExportLevel::Rust, + kind: SymbolExportKind::Text, + used: false, + }, + )); + } _ => { // Any other symbols don't qualify for sharing } @@ -385,6 +403,7 @@ fn upstream_monomorphizations_provider( let mut instances: DefIdMap<UnordMap<_, _>> = Default::default(); let drop_in_place_fn_def_id = tcx.lang_items().drop_in_place_fn(); + let async_drop_in_place_fn_def_id = tcx.lang_items().async_drop_in_place_fn(); for &cnum in cnums.iter() { for (exported_symbol, _) in tcx.exported_symbols(cnum).iter() { @@ -399,6 +418,18 @@ fn upstream_monomorphizations_provider( continue; } } + ExportedSymbol::AsyncDropGlueCtorShim(ty) => { + if let Some(async_drop_in_place_fn_def_id) = async_drop_in_place_fn_def_id { + ( + async_drop_in_place_fn_def_id, + tcx.mk_args(&[tcx.lifetimes.re_erased.into(), ty.into()]), + ) + } else { + // `drop_in_place` in place does not exist, don't try + // to use it. + continue; + } + } ExportedSymbol::NonGeneric(..) | ExportedSymbol::ThreadLocalShim(..) | ExportedSymbol::NoDefId(..) => { @@ -534,6 +565,13 @@ pub fn symbol_name_for_instance_in_crate<'tcx>( Instance::resolve_drop_in_place(tcx, ty), instantiating_crate, ), + ExportedSymbol::AsyncDropGlueCtorShim(ty) => { + rustc_symbol_mangling::symbol_name_for_instance_in_crate( + tcx, + Instance::resolve_async_drop_in_place(tcx, ty), + instantiating_crate, + ) + } ExportedSymbol::NoDefId(symbol_name) => symbol_name.to_string(), } } @@ -582,6 +620,9 @@ pub fn linking_symbol_name_for_instance_in_crate<'tcx>( // DropGlue always use the Rust calling convention and thus follow the target's default // symbol decoration scheme. ExportedSymbol::DropGlue(..) => None, + // AsyncDropGlueCtorShim always use the Rust calling convention and thus follow the + // target's default symbol decoration scheme. + ExportedSymbol::AsyncDropGlueCtorShim(..) => None, // NoDefId always follow the target's default symbol decoration scheme. ExportedSymbol::NoDefId(..) => None, // ThreadLocalShim always follow the target's default symbol decoration scheme. diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 452398e6d82..64c13fa7c1f 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -835,7 +835,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let def = instance.map(|i| i.def); - if let Some(ty::InstanceDef::DropGlue(_, None)) = def { + if let Some( + ty::InstanceDef::DropGlue(_, None) | ty::InstanceDef::AsyncDropGlueCtorShim(_, None), + ) = def + { // Empty drop glue; a no-op. let target = target.unwrap(); return helper.funclet_br(self, bx, target, mergeable_succ); diff --git a/compiler/rustc_const_eval/src/interpret/terminator.rs b/compiler/rustc_const_eval/src/interpret/terminator.rs index c0e27e86d50..908c4da71f1 100644 --- a/compiler/rustc_const_eval/src/interpret/terminator.rs +++ b/compiler/rustc_const_eval/src/interpret/terminator.rs @@ -558,6 +558,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { | ty::InstanceDef::CloneShim(..) | ty::InstanceDef::FnPtrAddrShim(..) | ty::InstanceDef::ThreadLocalShim(..) + | ty::InstanceDef::AsyncDropGlueCtorShim(..) | ty::InstanceDef::Item(_) => { // We need MIR for this fn let Some((body, instance)) = M::find_mir_or_eval_fn( diff --git a/compiler/rustc_hir/src/lang_items.rs b/compiler/rustc_hir/src/lang_items.rs index 2a796ca5465..879476f890e 100644 --- a/compiler/rustc_hir/src/lang_items.rs +++ b/compiler/rustc_hir/src/lang_items.rs @@ -162,6 +162,18 @@ language_item_table! { Drop, sym::drop, drop_trait, Target::Trait, GenericRequirement::None; Destruct, sym::destruct, destruct_trait, Target::Trait, GenericRequirement::None; + AsyncDrop, sym::async_drop, async_drop_trait, Target::Trait, GenericRequirement::Exact(0); + AsyncDestruct, sym::async_destruct, async_destruct_trait, Target::Trait, GenericRequirement::Exact(0); + AsyncDropInPlace, sym::async_drop_in_place, async_drop_in_place_fn, Target::Fn, GenericRequirement::Exact(1); + SurfaceAsyncDropInPlace, sym::surface_async_drop_in_place, surface_async_drop_in_place_fn, Target::Fn, GenericRequirement::Exact(1); + AsyncDropSurfaceDropInPlace, sym::async_drop_surface_drop_in_place, async_drop_surface_drop_in_place_fn, Target::Fn, GenericRequirement::Exact(1); + AsyncDropSlice, sym::async_drop_slice, async_drop_slice_fn, Target::Fn, GenericRequirement::Exact(1); + AsyncDropChain, sym::async_drop_chain, async_drop_chain_fn, Target::Fn, GenericRequirement::Exact(2); + AsyncDropNoop, sym::async_drop_noop, async_drop_noop_fn, Target::Fn, GenericRequirement::Exact(0); + AsyncDropFuse, sym::async_drop_fuse, async_drop_fuse_fn, Target::Fn, GenericRequirement::Exact(1); + AsyncDropDefer, sym::async_drop_defer, async_drop_defer_fn, Target::Fn, GenericRequirement::Exact(1); + AsyncDropEither, sym::async_drop_either, async_drop_either_fn, Target::Fn, GenericRequirement::Exact(3); + CoerceUnsized, sym::coerce_unsized, coerce_unsized_trait, Target::Trait, GenericRequirement::Minimum(1); DispatchFromDyn, sym::dispatch_from_dyn, dispatch_from_dyn_trait, Target::Trait, GenericRequirement::Minimum(1); @@ -281,6 +293,7 @@ language_item_table! { ExchangeMalloc, sym::exchange_malloc, exchange_malloc_fn, Target::Fn, GenericRequirement::None; DropInPlace, sym::drop_in_place, drop_in_place_fn, Target::Fn, GenericRequirement::Minimum(1); + FallbackSurfaceDrop, sym::fallback_surface_drop, fallback_surface_drop_fn, Target::Fn, GenericRequirement::None; AllocLayout, sym::alloc_layout, alloc_layout, Target::Struct, GenericRequirement::None; Start, sym::start, start_fn, Target::Fn, GenericRequirement::Exact(1); diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs index a64d3b9633f..dfd0b7c2945 100644 --- a/compiler/rustc_hir_typeck/src/callee.rs +++ b/compiler/rustc_hir_typeck/src/callee.rs @@ -38,8 +38,11 @@ pub fn check_legal_trait_for_method_call( receiver: Option<Span>, expr_span: Span, trait_id: DefId, + body_id: DefId, ) -> Result<(), ErrorGuaranteed> { - if tcx.lang_items().drop_trait() == Some(trait_id) { + if tcx.lang_items().drop_trait() == Some(trait_id) + && tcx.lang_items().fallback_surface_drop_fn() != Some(body_id) + { let sugg = if let Some(receiver) = receiver.filter(|s| !s.is_empty()) { errors::ExplicitDestructorCallSugg::Snippet { lo: expr_span.shrink_to_lo(), diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs index bd2454f6368..0b684fdf57b 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs @@ -1131,6 +1131,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { None, span, container_id, + self.body_id.to_def_id(), ) { self.set_tainted_by_errors(e); } diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs index 02759064abd..d57015282de 100644 --- a/compiler/rustc_hir_typeck/src/method/confirm.rs +++ b/compiler/rustc_hir_typeck/src/method/confirm.rs @@ -628,6 +628,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { Some(self.self_expr.span), self.call_expr.span, trait_def_id, + self.body_id.to_def_id(), ) { self.set_tainted_by_errors(e); } diff --git a/compiler/rustc_middle/src/middle/exported_symbols.rs b/compiler/rustc_middle/src/middle/exported_symbols.rs index e30b6b203d7..123b32f4aea 100644 --- a/compiler/rustc_middle/src/middle/exported_symbols.rs +++ b/compiler/rustc_middle/src/middle/exported_symbols.rs @@ -43,6 +43,7 @@ pub enum ExportedSymbol<'tcx> { NonGeneric(DefId), Generic(DefId, GenericArgsRef<'tcx>), DropGlue(Ty<'tcx>), + AsyncDropGlueCtorShim(Ty<'tcx>), ThreadLocalShim(DefId), NoDefId(ty::SymbolName<'tcx>), } @@ -59,6 +60,9 @@ impl<'tcx> ExportedSymbol<'tcx> { ExportedSymbol::DropGlue(ty) => { tcx.symbol_name(ty::Instance::resolve_drop_in_place(tcx, ty)) } + ExportedSymbol::AsyncDropGlueCtorShim(ty) => { + tcx.symbol_name(ty::Instance::resolve_async_drop_in_place(tcx, ty)) + } ExportedSymbol::ThreadLocalShim(def_id) => tcx.symbol_name(ty::Instance { def: ty::InstanceDef::ThreadLocalShim(def_id), args: ty::GenericArgs::empty(), diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs index 43e1318a75a..9eed7019782 100644 --- a/compiler/rustc_middle/src/mir/mono.rs +++ b/compiler/rustc_middle/src/mir/mono.rs @@ -65,7 +65,9 @@ impl<'tcx> MonoItem<'tcx> { match instance.def { // "Normal" functions size estimate: the number of // statements, plus one for the terminator. - InstanceDef::Item(..) | InstanceDef::DropGlue(..) => { + InstanceDef::Item(..) + | InstanceDef::DropGlue(..) + | InstanceDef::AsyncDropGlueCtorShim(..) => { let mir = tcx.instance_mir(instance.def); mir.basic_blocks.iter().map(|bb| bb.statements.len() + 1).sum() } @@ -406,7 +408,8 @@ impl<'tcx> CodegenUnit<'tcx> { | InstanceDef::DropGlue(..) | InstanceDef::CloneShim(..) | InstanceDef::ThreadLocalShim(..) - | InstanceDef::FnPtrAddrShim(..) => None, + | InstanceDef::FnPtrAddrShim(..) + | InstanceDef::AsyncDropGlueCtorShim(..) => None, } } MonoItem::Static(def_id) => def_id.as_local().map(Idx::index), diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs index 0c9ceae63c1..7a91d7383e5 100644 --- a/compiler/rustc_middle/src/mir/pretty.rs +++ b/compiler/rustc_middle/src/mir/pretty.rs @@ -187,6 +187,17 @@ fn dump_path<'tcx>( })); s } + ty::InstanceDef::AsyncDropGlueCtorShim(_, Some(ty)) => { + // Unfortunately, pretty-printed typed are not very filename-friendly. + // We dome some filtering. + let mut s = ".".to_owned(); + s.extend(ty.to_string().chars().filter_map(|c| match c { + ' ' => None, + ':' | '<' | '>' => Some('_'), + c => Some(c), + })); + s + } _ => String::new(), }; diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs index fc1ab0f12ac..a6d525230b0 100644 --- a/compiler/rustc_middle/src/mir/visit.rs +++ b/compiler/rustc_middle/src/mir/visit.rs @@ -350,12 +350,14 @@ macro_rules! make_mir_visitor { receiver_by_ref: _, } | ty::InstanceDef::CoroutineKindShim { coroutine_def_id: _def_id } | + ty::InstanceDef::AsyncDropGlueCtorShim(_def_id, None) | ty::InstanceDef::DropGlue(_def_id, None) => {} ty::InstanceDef::FnPtrShim(_def_id, ty) | ty::InstanceDef::DropGlue(_def_id, Some(ty)) | ty::InstanceDef::CloneShim(_def_id, ty) | - ty::InstanceDef::FnPtrAddrShim(_def_id, ty) => { + ty::InstanceDef::FnPtrAddrShim(_def_id, ty) | + ty::InstanceDef::AsyncDropGlueCtorShim(_def_id, Some(ty)) => { // FIXME(eddyb) use a better `TyContext` here. self.visit_ty($(& $mutability)? *ty, TyContext::Location(location)); } diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs index 0d625ff0fae..4ae79399ef4 100644 --- a/compiler/rustc_middle/src/query/mod.rs +++ b/compiler/rustc_middle/src/query/mod.rs @@ -1344,6 +1344,14 @@ rustc_queries! { query is_unpin_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool { desc { "computing whether `{}` is `Unpin`", env.value } } + /// Query backing `Ty::has_surface_async_drop`. + query has_surface_async_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool { + desc { "computing whether `{}` has `AsyncDrop` implementation", env.value } + } + /// Query backing `Ty::has_surface_drop`. + query has_surface_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool { + desc { "computing whether `{}` has `Drop` implementation", env.value } + } /// Query backing `Ty::needs_drop`. query needs_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool { desc { "computing whether `{}` needs drop", env.value } diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs index f8f59fbeab4..4002d0da790 100644 --- a/compiler/rustc_middle/src/ty/instance.rs +++ b/compiler/rustc_middle/src/ty/instance.rs @@ -168,6 +168,12 @@ pub enum InstanceDef<'tcx> { /// /// The `DefId` is for `FnPtr::addr`, the `Ty` is the type `T`. FnPtrAddrShim(DefId, Ty<'tcx>), + + /// `core::future::async_drop::async_drop_in_place::<'_, T>`. + /// + /// The `DefId` is for `core::future::async_drop::async_drop_in_place`, the `Ty` + /// is the type `T`. + AsyncDropGlueCtorShim(DefId, Option<Ty<'tcx>>), } impl<'tcx> Instance<'tcx> { @@ -210,7 +216,9 @@ impl<'tcx> Instance<'tcx> { InstanceDef::Item(def) => tcx .upstream_monomorphizations_for(def) .and_then(|monos| monos.get(&self.args).cloned()), - InstanceDef::DropGlue(_, Some(_)) => tcx.upstream_drop_glue_for(self.args), + InstanceDef::DropGlue(_, Some(_)) | InstanceDef::AsyncDropGlueCtorShim(_, _) => { + tcx.upstream_drop_glue_for(self.args) + } _ => None, } } @@ -235,7 +243,8 @@ impl<'tcx> InstanceDef<'tcx> { | ty::InstanceDef::CoroutineKindShim { coroutine_def_id: def_id } | InstanceDef::DropGlue(def_id, _) | InstanceDef::CloneShim(def_id, _) - | InstanceDef::FnPtrAddrShim(def_id, _) => def_id, + | InstanceDef::FnPtrAddrShim(def_id, _) + | InstanceDef::AsyncDropGlueCtorShim(def_id, _) => def_id, } } @@ -243,9 +252,9 @@ impl<'tcx> InstanceDef<'tcx> { pub fn def_id_if_not_guaranteed_local_codegen(self) -> Option<DefId> { match self { ty::InstanceDef::Item(def) => Some(def), - ty::InstanceDef::DropGlue(def_id, Some(_)) | InstanceDef::ThreadLocalShim(def_id) => { - Some(def_id) - } + ty::InstanceDef::DropGlue(def_id, Some(_)) + | InstanceDef::AsyncDropGlueCtorShim(def_id, _) + | InstanceDef::ThreadLocalShim(def_id) => Some(def_id), InstanceDef::VTableShim(..) | InstanceDef::ReifyShim(..) | InstanceDef::FnPtrShim(..) @@ -279,6 +288,7 @@ impl<'tcx> InstanceDef<'tcx> { let def_id = match *self { ty::InstanceDef::Item(def) => def, ty::InstanceDef::DropGlue(_, Some(_)) => return false, + ty::InstanceDef::AsyncDropGlueCtorShim(_, Some(_)) => return false, ty::InstanceDef::ThreadLocalShim(_) => return false, _ => return true, }; @@ -347,11 +357,13 @@ impl<'tcx> InstanceDef<'tcx> { | InstanceDef::ThreadLocalShim(..) | InstanceDef::FnPtrAddrShim(..) | InstanceDef::FnPtrShim(..) - | InstanceDef::DropGlue(_, Some(_)) => false, + | InstanceDef::DropGlue(_, Some(_)) + | InstanceDef::AsyncDropGlueCtorShim(_, Some(_)) => false, InstanceDef::ClosureOnceShim { .. } | InstanceDef::ConstructCoroutineInClosureShim { .. } | InstanceDef::CoroutineKindShim { .. } | InstanceDef::DropGlue(..) + | InstanceDef::AsyncDropGlueCtorShim(..) | InstanceDef::Item(_) | InstanceDef::Intrinsic(..) | InstanceDef::ReifyShim(..) @@ -396,6 +408,8 @@ fn fmt_instance( InstanceDef::DropGlue(_, Some(ty)) => write!(f, " - shim(Some({ty}))"), InstanceDef::CloneShim(_, ty) => write!(f, " - shim({ty})"), InstanceDef::FnPtrAddrShim(_, ty) => write!(f, " - shim({ty})"), + InstanceDef::AsyncDropGlueCtorShim(_, None) => write!(f, " - shim(None)"), + InstanceDef::AsyncDropGlueCtorShim(_, Some(ty)) => write!(f, " - shim(Some({ty}))"), } } @@ -638,6 +652,12 @@ impl<'tcx> Instance<'tcx> { Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args) } + pub fn resolve_async_drop_in_place(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ty::Instance<'tcx> { + let def_id = tcx.require_lang_item(LangItem::AsyncDropInPlace, None); + let args = tcx.mk_args(&[ty.into()]); + Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args) + } + #[instrument(level = "debug", skip(tcx), ret)] pub fn fn_once_adapter_instance( tcx: TyCtxt<'tcx>, diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index d0a69c6fd2c..cc026e349d7 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -1797,7 +1797,8 @@ impl<'tcx> TyCtxt<'tcx> { | ty::InstanceDef::DropGlue(..) | ty::InstanceDef::CloneShim(..) | ty::InstanceDef::ThreadLocalShim(..) - | ty::InstanceDef::FnPtrAddrShim(..) => self.mir_shims(instance), + | ty::InstanceDef::FnPtrAddrShim(..) + | ty::InstanceDef::AsyncDropGlueCtorShim(..) => self.mir_shims(instance), } } diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index 2a1af97ef24..0184ff54979 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -24,6 +24,7 @@ use rustc_target::abi::{FieldIdx, VariantIdx, FIRST_VARIANT}; use rustc_target::spec::abi::{self, Abi}; use std::assert_matches::debug_assert_matches; use std::borrow::Cow; +use std::iter; use std::ops::{ControlFlow, Deref, Range}; use ty::util::IntTypeExt; @@ -2316,6 +2317,133 @@ impl<'tcx> Ty<'tcx> { } } + /// Returns the type of the async destructor of this type. + pub fn async_destructor_ty(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> Ty<'tcx> { + if self.is_async_destructor_noop(tcx, param_env) || matches!(self.kind(), ty::Error(_)) { + return Ty::async_destructor_combinator(tcx, LangItem::AsyncDropNoop) + .instantiate_identity(); + } + match *self.kind() { + ty::Param(_) | ty::Alias(..) | ty::Infer(ty::TyVar(_)) => { + let assoc_items = tcx + .associated_item_def_ids(tcx.require_lang_item(LangItem::AsyncDestruct, None)); + Ty::new_projection(tcx, assoc_items[0], [self]) + } + + ty::Array(elem_ty, _) | ty::Slice(elem_ty) => { + let dtor = Ty::async_destructor_combinator(tcx, LangItem::AsyncDropSlice) + .instantiate(tcx, &[elem_ty.into()]); + Ty::async_destructor_combinator(tcx, LangItem::AsyncDropFuse) + .instantiate(tcx, &[dtor.into()]) + } + + ty::Adt(adt_def, args) if adt_def.is_enum() || adt_def.is_struct() => self + .adt_async_destructor_ty( + tcx, + adt_def.variants().iter().map(|v| v.fields.iter().map(|f| f.ty(tcx, args))), + param_env, + ), + ty::Tuple(tys) => self.adt_async_destructor_ty(tcx, iter::once(tys), param_env), + ty::Closure(_, args) => self.adt_async_destructor_ty( + tcx, + iter::once(args.as_closure().upvar_tys()), + param_env, + ), + ty::CoroutineClosure(_, args) => self.adt_async_destructor_ty( + tcx, + iter::once(args.as_coroutine_closure().upvar_tys()), + param_env, + ), + + ty::Adt(adt_def, _) => { + assert!(adt_def.is_union()); + + let surface_drop = self.surface_async_dropper_ty(tcx, param_env).unwrap(); + + Ty::async_destructor_combinator(tcx, LangItem::AsyncDropFuse) + .instantiate(tcx, &[surface_drop.into()]) + } + + ty::Bound(..) + | ty::Foreign(_) + | ty::Placeholder(_) + | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => { + bug!("`async_destructor_ty` applied to unexpected type: {self:?}") + } + + _ => bug!("`async_destructor_ty` is not yet implemented for type: {self:?}"), + } + } + + fn adt_async_destructor_ty<I>( + self, + tcx: TyCtxt<'tcx>, + variants: I, + param_env: ParamEnv<'tcx>, + ) -> Ty<'tcx> + where + I: Iterator + ExactSizeIterator, + I::Item: IntoIterator<Item = Ty<'tcx>>, + { + debug_assert!(!self.is_async_destructor_noop(tcx, param_env)); + + let defer = Ty::async_destructor_combinator(tcx, LangItem::AsyncDropDefer); + let chain = Ty::async_destructor_combinator(tcx, LangItem::AsyncDropChain); + + let noop = + Ty::async_destructor_combinator(tcx, LangItem::AsyncDropNoop).instantiate_identity(); + let either = Ty::async_destructor_combinator(tcx, LangItem::AsyncDropEither); + + let variants_dtor = variants + .into_iter() + .map(|variant| { + variant + .into_iter() + .map(|ty| defer.instantiate(tcx, &[ty.into()])) + .reduce(|acc, next| chain.instantiate(tcx, &[acc.into(), next.into()])) + .unwrap_or(noop) + }) + .reduce(|other, matched| { + either.instantiate(tcx, &[other.into(), matched.into(), self.into()]) + }) + .unwrap(); + + let dtor = if let Some(dropper_ty) = self.surface_async_dropper_ty(tcx, param_env) { + Ty::async_destructor_combinator(tcx, LangItem::AsyncDropChain) + .instantiate(tcx, &[dropper_ty.into(), variants_dtor.into()]) + } else { + variants_dtor + }; + + Ty::async_destructor_combinator(tcx, LangItem::AsyncDropFuse) + .instantiate(tcx, &[dtor.into()]) + } + + fn surface_async_dropper_ty( + self, + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + ) -> Option<Ty<'tcx>> { + if self.has_surface_async_drop(tcx, param_env) { + Some(LangItem::SurfaceAsyncDropInPlace) + } else if self.has_surface_drop(tcx, param_env) { + Some(LangItem::AsyncDropSurfaceDropInPlace) + } else { + None + } + .map(|dropper| { + Ty::async_destructor_combinator(tcx, dropper).instantiate(tcx, &[self.into()]) + }) + } + + fn async_destructor_combinator( + tcx: TyCtxt<'tcx>, + lang_item: LangItem, + ) -> ty::EarlyBinder<Ty<'tcx>> { + tcx.fn_sig(tcx.require_lang_item(lang_item, None)) + .map_bound(|fn_sig| fn_sig.output().no_bound_vars().unwrap()) + } + /// Returns the type of metadata for (potentially fat) pointers to this type, /// or the struct tail if the metadata type cannot be determined. pub fn ptr_metadata_ty_or_tail( diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs index 793ac126aa6..42e0565db83 100644 --- a/compiler/rustc_middle/src/ty/util.rs +++ b/compiler/rustc_middle/src/ty/util.rs @@ -1303,6 +1303,98 @@ impl<'tcx> Ty<'tcx> { } } + /// Checks whether values of this type `T` implements the `AsyncDrop` + /// trait. + pub fn has_surface_async_drop(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool { + self.could_have_surface_async_drop() && tcx.has_surface_async_drop_raw(param_env.and(self)) + } + + /// Fast path helper for testing if a type has `AsyncDrop` + /// implementation. + /// + /// Returning `false` means the type is known to not have `AsyncDrop` + /// implementation. Returning `true` means nothing -- could be + /// `AsyncDrop`, might not be. + fn could_have_surface_async_drop(self) -> bool { + !self.is_async_destructor_trivially_noop() + && !matches!( + self.kind(), + ty::Tuple(_) + | ty::Slice(_) + | ty::Array(_, _) + | ty::Closure(..) + | ty::CoroutineClosure(..) + | ty::Coroutine(..) + ) + } + + /// Checks whether values of this type `T` implements the `Drop` + /// trait. + pub fn has_surface_drop(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool { + self.could_have_surface_drop() && tcx.has_surface_drop_raw(param_env.and(self)) + } + + /// Fast path helper for testing if a type has `Drop` implementation. + /// + /// Returning `false` means the type is known to not have `Drop` + /// implementation. Returning `true` means nothing -- could be + /// `Drop`, might not be. + fn could_have_surface_drop(self) -> bool { + !self.is_async_destructor_trivially_noop() + && !matches!( + self.kind(), + ty::Tuple(_) + | ty::Slice(_) + | ty::Array(_, _) + | ty::Closure(..) + | ty::CoroutineClosure(..) + | ty::Coroutine(..) + ) + } + + /// Checks whether values of this type `T` implement has noop async destructor. + // + // FIXME: implement optimization to make ADTs, which do not need drop, + // to skip fields or to have noop async destructor. + pub fn is_async_destructor_noop( + self, + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + ) -> bool { + self.is_async_destructor_trivially_noop() + || if let ty::Adt(adt_def, _) = self.kind() { + (adt_def.is_union() || adt_def.is_payloadfree()) + && !self.has_surface_async_drop(tcx, param_env) + && !self.has_surface_drop(tcx, param_env) + } else { + false + } + } + + /// Fast path helper for testing if a type has noop async destructor. + /// + /// Returning `true` means the type is known to have noop async destructor + /// implementation. Returning `true` means nothing -- could be + /// `Drop`, might not be. + fn is_async_destructor_trivially_noop(self) -> bool { + match self.kind() { + ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Bool + | ty::Char + | ty::Str + | ty::Never + | ty::Ref(..) + | ty::RawPtr(..) + | ty::FnDef(..) + | ty::FnPtr(_) => true, + ty::Tuple(tys) => tys.is_empty(), + ty::Adt(adt_def, _) => adt_def.is_manually_drop(), + _ => false, + } + } + /// If `ty.needs_drop(...)` returns `true`, then `ty` is definitely /// non-copy and *might* have a destructor attached; if it returns /// `false`, then `ty` definitely has no destructor (i.e., no drop glue). diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 625d8f53939..7dcff458ced 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -332,7 +332,8 @@ impl<'tcx> Inliner<'tcx> { | InstanceDef::DropGlue(..) | InstanceDef::CloneShim(..) | InstanceDef::ThreadLocalShim(..) - | InstanceDef::FnPtrAddrShim(..) => return Ok(()), + | InstanceDef::FnPtrAddrShim(..) + | InstanceDef::AsyncDropGlueCtorShim(..) => return Ok(()), } if self.tcx.is_constructor(callee_def_id) { @@ -1083,7 +1084,8 @@ fn try_instance_mir<'tcx>( tcx: TyCtxt<'tcx>, instance: InstanceDef<'tcx>, ) -> Result<&'tcx Body<'tcx>, &'static str> { - if let ty::InstanceDef::DropGlue(_, Some(ty)) = instance + if let ty::InstanceDef::DropGlue(_, Some(ty)) + | ty::InstanceDef::AsyncDropGlueCtorShim(_, Some(ty)) = instance && let ty::Adt(def, args) = ty.kind() { let fields = def.all_fields(); diff --git a/compiler/rustc_mir_transform/src/inline/cycle.rs b/compiler/rustc_mir_transform/src/inline/cycle.rs index 99c7b616f1b..8c5f965108b 100644 --- a/compiler/rustc_mir_transform/src/inline/cycle.rs +++ b/compiler/rustc_mir_transform/src/inline/cycle.rs @@ -94,8 +94,10 @@ pub(crate) fn mir_callgraph_reachable<'tcx>( | InstanceDef::CloneShim(..) => {} // This shim does not call any other functions, thus there can be no recursion. - InstanceDef::FnPtrAddrShim(..) => continue, - InstanceDef::DropGlue(..) => { + InstanceDef::FnPtrAddrShim(..) => { + continue; + } + InstanceDef::DropGlue(..) | InstanceDef::AsyncDropGlueCtorShim(..) => { // FIXME: A not fully instantiated drop shim can cause ICEs if one attempts to // have its MIR built. Likely oli-obk just screwed up the `ParamEnv`s, so this // needs some more analysis. diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index fa6906bdd55..1c85a604053 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -22,6 +22,8 @@ use crate::{ use rustc_middle::mir::patch::MirPatch; use rustc_mir_dataflow::elaborate_drops::{self, DropElaborator, DropFlagMode, DropStyle}; +mod async_destructor_ctor; + pub fn provide(providers: &mut Providers) { providers.mir_shims = make_shim; } @@ -127,6 +129,9 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<' ty::InstanceDef::ThreadLocalShim(..) => build_thread_local_shim(tcx, instance), ty::InstanceDef::CloneShim(def_id, ty) => build_clone_shim(tcx, def_id, ty), ty::InstanceDef::FnPtrAddrShim(def_id, ty) => build_fn_ptr_addr_shim(tcx, def_id, ty), + ty::InstanceDef::AsyncDropGlueCtorShim(def_id, ty) => { + async_destructor_ctor::build_async_destructor_ctor_shim(tcx, def_id, ty) + } ty::InstanceDef::Virtual(..) => { bug!("InstanceDef::Virtual ({:?}) is for direct calls only", instance) } diff --git a/compiler/rustc_mir_transform/src/shim/async_destructor_ctor.rs b/compiler/rustc_mir_transform/src/shim/async_destructor_ctor.rs new file mode 100644 index 00000000000..80eadb9abdc --- /dev/null +++ b/compiler/rustc_mir_transform/src/shim/async_destructor_ctor.rs @@ -0,0 +1,618 @@ +use std::iter; + +use itertools::Itertools; +use rustc_ast::Mutability; +use rustc_const_eval::interpret; +use rustc_hir::def_id::DefId; +use rustc_hir::lang_items::LangItem; +use rustc_index::{Idx, IndexVec}; +use rustc_middle::mir::{ + BasicBlock, BasicBlockData, Body, CallSource, CastKind, Const, ConstOperand, ConstValue, Local, + LocalDecl, MirSource, Operand, Place, PlaceElem, Rvalue, SourceInfo, Statement, StatementKind, + Terminator, TerminatorKind, UnwindAction, UnwindTerminateReason, RETURN_PLACE, +}; +use rustc_middle::ty::adjustment::PointerCoercion; +use rustc_middle::ty::util::Discr; +use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_span::source_map::respan; +use rustc_span::{Span, Symbol}; +use rustc_target::abi::{FieldIdx, VariantIdx}; +use rustc_target::spec::PanicStrategy; + +use super::{local_decls_for_sig, new_body}; + +pub fn build_async_destructor_ctor_shim<'tcx>( + tcx: TyCtxt<'tcx>, + def_id: DefId, + ty: Option<Ty<'tcx>>, +) -> Body<'tcx> { + debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty); + + AsyncDestructorCtorShimBuilder::new(tcx, def_id, ty).build() +} + +/// Builder for async_drop_in_place shim. Functions as a stack machine +/// to build up an expression using combinators. Stack contains pairs +/// of locals and types. Combinator is a not yet instantiated pair of a +/// function and a type, is considered to be an operator which consumes +/// operands from the stack by instantiating its function and its type +/// with operand types and moving locals into the function call. Top +/// pair is considered to be the last operand. +// FIXME: add mir-opt tests +struct AsyncDestructorCtorShimBuilder<'tcx> { + tcx: TyCtxt<'tcx>, + def_id: DefId, + self_ty: Option<Ty<'tcx>>, + span: Span, + source_info: SourceInfo, + param_env: ty::ParamEnv<'tcx>, + + stack: Vec<Operand<'tcx>>, + last_bb: BasicBlock, + top_cleanup_bb: Option<BasicBlock>, + + locals: IndexVec<Local, LocalDecl<'tcx>>, + bbs: IndexVec<BasicBlock, BasicBlockData<'tcx>>, +} + +#[derive(Clone, Copy)] +enum SurfaceDropKind { + Async, + Sync, +} + +impl<'tcx> AsyncDestructorCtorShimBuilder<'tcx> { + const SELF_PTR: Local = Local::from_u32(1); + const INPUT_COUNT: usize = 1; + const MAX_STACK_LEN: usize = 2; + + fn new(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Option<Ty<'tcx>>) -> Self { + let args = if let Some(ty) = self_ty { + tcx.mk_args(&[ty.into()]) + } else { + ty::GenericArgs::identity_for_item(tcx, def_id) + }; + let sig = tcx.fn_sig(def_id).instantiate(tcx, args); + let sig = tcx.instantiate_bound_regions_with_erased(sig); + let span = tcx.def_span(def_id); + + let source_info = SourceInfo::outermost(span); + + debug_assert_eq!(sig.inputs().len(), Self::INPUT_COUNT); + let locals = local_decls_for_sig(&sig, span); + + // Usual case: noop() + unwind resume + return + let mut bbs = IndexVec::with_capacity(3); + let param_env = tcx.param_env_reveal_all_normalized(def_id); + AsyncDestructorCtorShimBuilder { + tcx, + def_id, + self_ty, + span, + source_info, + param_env, + + stack: Vec::with_capacity(Self::MAX_STACK_LEN), + last_bb: bbs.push(BasicBlockData::new(None)), + top_cleanup_bb: match tcx.sess.panic_strategy() { + PanicStrategy::Unwind => { + // Don't drop input arg because it's just a pointer + Some(bbs.push(BasicBlockData { + statements: Vec::new(), + terminator: Some(Terminator { + source_info, + kind: TerminatorKind::UnwindResume, + }), + is_cleanup: true, + })) + } + PanicStrategy::Abort => None, + }, + + locals, + bbs, + } + } + + fn build(self) -> Body<'tcx> { + let (tcx, def_id, Some(self_ty)) = (self.tcx, self.def_id, self.self_ty) else { + return self.build_zst_output(); + }; + + let surface_drop_kind = || { + let param_env = tcx.param_env_reveal_all_normalized(def_id); + if self_ty.has_surface_async_drop(tcx, param_env) { + Some(SurfaceDropKind::Async) + } else if self_ty.has_surface_drop(tcx, param_env) { + Some(SurfaceDropKind::Sync) + } else { + None + } + }; + + match self_ty.kind() { + ty::Array(elem_ty, _) => self.build_slice(true, *elem_ty), + ty::Slice(elem_ty) => self.build_slice(false, *elem_ty), + + ty::Tuple(elem_tys) => self.build_chain(None, elem_tys.iter()), + ty::Adt(adt_def, args) if adt_def.is_struct() => { + let field_tys = adt_def.non_enum_variant().fields.iter().map(|f| f.ty(tcx, args)); + self.build_chain(surface_drop_kind(), field_tys) + } + ty::Closure(_, args) => self.build_chain(None, args.as_closure().upvar_tys().iter()), + ty::CoroutineClosure(_, args) => { + self.build_chain(None, args.as_coroutine_closure().upvar_tys().iter()) + } + + ty::Adt(adt_def, args) if adt_def.is_enum() => { + self.build_enum(*adt_def, *args, surface_drop_kind()) + } + + ty::Adt(adt_def, _) => { + assert!(adt_def.is_union()); + match surface_drop_kind().unwrap() { + SurfaceDropKind::Async => self.build_fused_async_surface(), + SurfaceDropKind::Sync => self.build_fused_sync_surface(), + } + } + + ty::Bound(..) + | ty::Foreign(_) + | ty::Placeholder(_) + | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_) | ty::TyVar(_)) + | ty::Param(_) + | ty::Alias(..) => { + bug!("Building async destructor for unexpected type: {self_ty:?}") + } + + _ => { + bug!( + "Building async destructor constructor shim is not yet implemented for type: {self_ty:?}" + ) + } + } + } + + fn build_enum( + mut self, + adt_def: ty::AdtDef<'tcx>, + args: ty::GenericArgsRef<'tcx>, + surface_drop: Option<SurfaceDropKind>, + ) -> Body<'tcx> { + let tcx = self.tcx; + + let surface = match surface_drop { + None => None, + Some(kind) => { + self.put_self(); + Some(match kind { + SurfaceDropKind::Async => self.combine_async_surface(), + SurfaceDropKind::Sync => self.combine_sync_surface(), + }) + } + }; + + let mut other = None; + for (variant_idx, discr) in adt_def.discriminants(tcx) { + let variant = adt_def.variant(variant_idx); + + let mut chain = None; + for (field_idx, field) in variant.fields.iter_enumerated() { + let field_ty = field.ty(tcx, args); + self.put_variant_field(variant.name, variant_idx, field_idx, field_ty); + let defer = self.combine_defer(field_ty); + chain = Some(match chain { + None => defer, + Some(chain) => self.combine_chain(chain, defer), + }) + } + let variant_dtor = chain.unwrap_or_else(|| self.put_noop()); + + other = Some(match other { + None => variant_dtor, + Some(other) => { + self.put_self(); + self.put_discr(discr); + self.combine_either(other, variant_dtor) + } + }); + } + let variants_dtor = other.unwrap_or_else(|| self.put_noop()); + + let dtor = match surface { + None => variants_dtor, + Some(surface) => self.combine_chain(surface, variants_dtor), + }; + self.combine_fuse(dtor); + self.return_() + } + + fn build_chain<I>(mut self, surface_drop: Option<SurfaceDropKind>, elem_tys: I) -> Body<'tcx> + where + I: Iterator<Item = Ty<'tcx>> + ExactSizeIterator, + { + let surface = match surface_drop { + None => None, + Some(kind) => { + self.put_self(); + Some(match kind { + SurfaceDropKind::Async => self.combine_async_surface(), + SurfaceDropKind::Sync => self.combine_sync_surface(), + }) + } + }; + + let mut chain = None; + for (field_idx, field_ty) in elem_tys.enumerate().map(|(i, ty)| (FieldIdx::new(i), ty)) { + self.put_field(field_idx, field_ty); + let defer = self.combine_defer(field_ty); + chain = Some(match chain { + None => defer, + Some(chain) => self.combine_chain(chain, defer), + }) + } + let chain = chain.unwrap_or_else(|| self.put_noop()); + + let dtor = match surface { + None => chain, + Some(surface) => self.combine_chain(surface, chain), + }; + self.combine_fuse(dtor); + self.return_() + } + + fn build_zst_output(mut self) -> Body<'tcx> { + self.put_zst_output(); + self.return_() + } + + fn build_fused_async_surface(mut self) -> Body<'tcx> { + self.put_self(); + let surface = self.combine_async_surface(); + self.combine_fuse(surface); + self.return_() + } + + fn build_fused_sync_surface(mut self) -> Body<'tcx> { + self.put_self(); + let surface = self.combine_sync_surface(); + self.combine_fuse(surface); + self.return_() + } + + fn build_slice(mut self, is_array: bool, elem_ty: Ty<'tcx>) -> Body<'tcx> { + if is_array { + self.put_array_as_slice(elem_ty) + } else { + self.put_self() + } + let dtor = self.combine_slice(elem_ty); + self.combine_fuse(dtor); + self.return_() + } + + fn put_zst_output(&mut self) { + let return_ty = self.locals[RETURN_PLACE].ty; + self.put_operand(Operand::Constant(Box::new(ConstOperand { + span: self.span, + user_ty: None, + const_: Const::zero_sized(return_ty), + }))); + } + + /// Puts `to_drop: *mut Self` on top of the stack. + fn put_self(&mut self) { + self.put_operand(Operand::Copy(Self::SELF_PTR.into())) + } + + /// Given that `Self is [ElemTy; N]` puts `to_drop: *mut [ElemTy]` + /// on top of the stack. + fn put_array_as_slice(&mut self, elem_ty: Ty<'tcx>) { + let slice_ptr_ty = Ty::new_mut_ptr(self.tcx, Ty::new_slice(self.tcx, elem_ty)); + self.put_temp_rvalue(Rvalue::Cast( + CastKind::PointerCoercion(PointerCoercion::Unsize), + Operand::Copy(Self::SELF_PTR.into()), + slice_ptr_ty, + )) + } + + /// If given Self is a struct puts `to_drop: *mut FieldTy` on top + /// of the stack. + fn put_field(&mut self, field: FieldIdx, field_ty: Ty<'tcx>) { + let place = Place { + local: Self::SELF_PTR, + projection: self + .tcx + .mk_place_elems(&[PlaceElem::Deref, PlaceElem::Field(field, field_ty)]), + }; + self.put_temp_rvalue(Rvalue::AddressOf(Mutability::Mut, place)) + } + + /// If given Self is an enum puts `to_drop: *mut FieldTy` on top of + /// the stack. + fn put_variant_field( + &mut self, + variant_sym: Symbol, + variant: VariantIdx, + field: FieldIdx, + field_ty: Ty<'tcx>, + ) { + let place = Place { + local: Self::SELF_PTR, + projection: self.tcx.mk_place_elems(&[ + PlaceElem::Deref, + PlaceElem::Downcast(Some(variant_sym), variant), + PlaceElem::Field(field, field_ty), + ]), + }; + self.put_temp_rvalue(Rvalue::AddressOf(Mutability::Mut, place)) + } + + /// If given Self is an enum puts `to_drop: *mut FieldTy` on top of + /// the stack. + fn put_discr(&mut self, discr: Discr<'tcx>) { + let (size, _) = discr.ty.int_size_and_signed(self.tcx); + self.put_operand(Operand::const_from_scalar( + self.tcx, + discr.ty, + interpret::Scalar::from_uint(discr.val, size), + self.span, + )); + } + + /// Puts `x: RvalueType` on top of the stack. + fn put_temp_rvalue(&mut self, rvalue: Rvalue<'tcx>) { + let last_bb = &mut self.bbs[self.last_bb]; + debug_assert!(last_bb.terminator.is_none()); + let source_info = self.source_info; + + let local_ty = rvalue.ty(&self.locals, self.tcx); + // We need to create a new local to be able to "consume" it with + // a combinator + let local = self.locals.push(LocalDecl::with_source_info(local_ty, source_info)); + last_bb.statements.extend_from_slice(&[ + Statement { source_info, kind: StatementKind::StorageLive(local) }, + Statement { + source_info, + kind: StatementKind::Assign(Box::new((local.into(), rvalue))), + }, + ]); + + self.put_operand(Operand::Move(local.into())); + } + + /// Puts operand on top of the stack. + fn put_operand(&mut self, operand: Operand<'tcx>) { + if let Some(top_cleanup_bb) = &mut self.top_cleanup_bb { + let source_info = self.source_info; + match &operand { + Operand::Copy(_) | Operand::Constant(_) => { + *top_cleanup_bb = self.bbs.push(BasicBlockData { + statements: Vec::new(), + terminator: Some(Terminator { + source_info, + kind: TerminatorKind::Goto { target: *top_cleanup_bb }, + }), + is_cleanup: true, + }); + } + Operand::Move(place) => { + let local = place.as_local().unwrap(); + *top_cleanup_bb = self.bbs.push(BasicBlockData { + statements: Vec::new(), + terminator: Some(Terminator { + source_info, + kind: if self.locals[local].ty.needs_drop(self.tcx, self.param_env) { + TerminatorKind::Drop { + place: local.into(), + target: *top_cleanup_bb, + unwind: UnwindAction::Terminate( + UnwindTerminateReason::InCleanup, + ), + replace: false, + } + } else { + TerminatorKind::Goto { target: *top_cleanup_bb } + }, + }), + is_cleanup: true, + }); + } + }; + } + self.stack.push(operand); + } + + /// Puts `noop: async_drop::Noop` on top of the stack + fn put_noop(&mut self) -> Ty<'tcx> { + self.apply_combinator(0, LangItem::AsyncDropNoop, &[]) + } + + fn combine_async_surface(&mut self) -> Ty<'tcx> { + self.apply_combinator(1, LangItem::SurfaceAsyncDropInPlace, &[self.self_ty.unwrap().into()]) + } + + fn combine_sync_surface(&mut self) -> Ty<'tcx> { + self.apply_combinator( + 1, + LangItem::AsyncDropSurfaceDropInPlace, + &[self.self_ty.unwrap().into()], + ) + } + + fn combine_fuse(&mut self, inner_future_ty: Ty<'tcx>) -> Ty<'tcx> { + self.apply_combinator(1, LangItem::AsyncDropFuse, &[inner_future_ty.into()]) + } + + fn combine_slice(&mut self, elem_ty: Ty<'tcx>) -> Ty<'tcx> { + self.apply_combinator(1, LangItem::AsyncDropSlice, &[elem_ty.into()]) + } + + fn combine_defer(&mut self, to_drop_ty: Ty<'tcx>) -> Ty<'tcx> { + self.apply_combinator(1, LangItem::AsyncDropDefer, &[to_drop_ty.into()]) + } + + fn combine_chain(&mut self, first: Ty<'tcx>, second: Ty<'tcx>) -> Ty<'tcx> { + self.apply_combinator(2, LangItem::AsyncDropChain, &[first.into(), second.into()]) + } + + fn combine_either(&mut self, other: Ty<'tcx>, matched: Ty<'tcx>) -> Ty<'tcx> { + self.apply_combinator( + 4, + LangItem::AsyncDropEither, + &[other.into(), matched.into(), self.self_ty.unwrap().into()], + ) + } + + fn return_(mut self) -> Body<'tcx> { + let last_bb = &mut self.bbs[self.last_bb]; + debug_assert!(last_bb.terminator.is_none()); + let source_info = self.source_info; + + let (1, Some(output)) = (self.stack.len(), self.stack.pop()) else { + span_bug!( + self.span, + "async destructor ctor shim builder finished with invalid number of stack items: expected 1 found {}", + self.stack.len(), + ) + }; + #[cfg(debug_assertions)] + if let Some(ty) = self.self_ty { + debug_assert_eq!( + output.ty(&self.locals, self.tcx), + ty.async_destructor_ty(self.tcx, self.param_env), + "output async destructor types did not match for type: {ty:?}", + ); + } + + let dead_storage = match &output { + Operand::Move(place) => Some(Statement { + source_info, + kind: StatementKind::StorageDead(place.as_local().unwrap()), + }), + _ => None, + }; + + last_bb.statements.extend( + iter::once(Statement { + source_info, + kind: StatementKind::Assign(Box::new((RETURN_PLACE.into(), Rvalue::Use(output)))), + }) + .chain(dead_storage), + ); + + last_bb.terminator = Some(Terminator { source_info, kind: TerminatorKind::Return }); + + let source = MirSource::from_instance(ty::InstanceDef::AsyncDropGlueCtorShim( + self.def_id, + self.self_ty, + )); + new_body(source, self.bbs, self.locals, Self::INPUT_COUNT, self.span) + } + + fn apply_combinator( + &mut self, + arity: usize, + function: LangItem, + args: &[ty::GenericArg<'tcx>], + ) -> Ty<'tcx> { + let function = self.tcx.require_lang_item(function, Some(self.span)); + let operands_split = self + .stack + .len() + .checked_sub(arity) + .expect("async destructor ctor shim combinator tried to consume too many items"); + let operands = &self.stack[operands_split..]; + + let func_ty = Ty::new_fn_def(self.tcx, function, args.iter().copied()); + let func_sig = func_ty.fn_sig(self.tcx).no_bound_vars().unwrap(); + #[cfg(debug_assertions)] + operands.iter().zip(func_sig.inputs()).for_each(|(operand, expected_ty)| { + let operand_ty = operand.ty(&self.locals, self.tcx); + if operand_ty == *expected_ty { + return; + } + + // If projection of Discriminant then compare with `Ty::discriminant_ty` + if let ty::Alias(ty::AliasKind::Projection, ty::AliasTy { args, def_id, .. }) = + expected_ty.kind() + && Some(*def_id) == self.tcx.lang_items().discriminant_type() + && args.first().unwrap().as_type().unwrap().discriminant_ty(self.tcx) == operand_ty + { + return; + } + + span_bug!( + self.span, + "Operand type and combinator argument type are not equal. + operand_ty: {:?} + argument_ty: {:?} +", + operand_ty, + expected_ty + ); + }); + + let target = self.bbs.push(BasicBlockData { + statements: operands + .iter() + .rev() + .filter_map(|o| { + if let Operand::Move(Place { local, projection }) = o { + assert!(projection.is_empty()); + Some(Statement { + source_info: self.source_info, + kind: StatementKind::StorageDead(*local), + }) + } else { + None + } + }) + .collect(), + terminator: None, + is_cleanup: false, + }); + + let dest_ty = func_sig.output(); + let dest = + self.locals.push(LocalDecl::with_source_info(dest_ty, self.source_info).immutable()); + + let unwind = if let Some(top_cleanup_bb) = &mut self.top_cleanup_bb { + for _ in 0..arity { + *top_cleanup_bb = + self.bbs[*top_cleanup_bb].terminator().successors().exactly_one().ok().unwrap(); + } + UnwindAction::Cleanup(*top_cleanup_bb) + } else { + UnwindAction::Unreachable + }; + + let last_bb = &mut self.bbs[self.last_bb]; + debug_assert!(last_bb.terminator.is_none()); + last_bb.statements.push(Statement { + source_info: self.source_info, + kind: StatementKind::StorageLive(dest), + }); + last_bb.terminator = Some(Terminator { + source_info: self.source_info, + kind: TerminatorKind::Call { + func: Operand::Constant(Box::new(ConstOperand { + span: self.span, + user_ty: None, + const_: Const::Val(ConstValue::ZeroSized, func_ty), + })), + destination: dest.into(), + target: Some(target), + unwind, + call_source: CallSource::Misc, + fn_span: self.span, + args: self.stack.drain(operands_split..).map(|o| respan(self.span, o)).collect(), + }, + }); + + self.put_operand(Operand::Move(dest.into())); + self.last_bb = target; + + dest_ty + } +} diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 36d623fd93e..a8fa6fe002d 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -966,13 +966,14 @@ fn visit_instance_use<'tcx>( ty::InstanceDef::ThreadLocalShim(..) => { bug!("{:?} being reified", instance); } - ty::InstanceDef::DropGlue(_, None) => { + ty::InstanceDef::DropGlue(_, None) | ty::InstanceDef::AsyncDropGlueCtorShim(_, None) => { // Don't need to emit noop drop glue if we are calling directly. if !is_direct_call { output.push(create_fn_mono_item(tcx, instance, source)); } } ty::InstanceDef::DropGlue(_, Some(_)) + | ty::InstanceDef::AsyncDropGlueCtorShim(_, Some(_)) | ty::InstanceDef::VTableShim(..) | ty::InstanceDef::ReifyShim(..) | ty::InstanceDef::ClosureOnceShim { .. } diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs index 5a92657cb40..23e07890bb6 100644 --- a/compiler/rustc_monomorphize/src/partitioning.rs +++ b/compiler/rustc_monomorphize/src/partitioning.rs @@ -625,7 +625,8 @@ fn characteristic_def_id_of_mono_item<'tcx>( | ty::InstanceDef::Virtual(..) | ty::InstanceDef::CloneShim(..) | ty::InstanceDef::ThreadLocalShim(..) - | ty::InstanceDef::FnPtrAddrShim(..) => return None, + | ty::InstanceDef::FnPtrAddrShim(..) + | ty::InstanceDef::AsyncDropGlueCtorShim(..) => return None, }; // If this is a method, we want to put it into the same module as @@ -769,7 +770,9 @@ fn mono_item_visibility<'tcx>( }; let def_id = match instance.def { - InstanceDef::Item(def_id) | InstanceDef::DropGlue(def_id, Some(_)) => def_id, + InstanceDef::Item(def_id) + | InstanceDef::DropGlue(def_id, Some(_)) + | InstanceDef::AsyncDropGlueCtorShim(def_id, Some(_)) => def_id, // We match the visibility of statics here InstanceDef::ThreadLocalShim(def_id) => { @@ -786,6 +789,7 @@ fn mono_item_visibility<'tcx>( | InstanceDef::ConstructCoroutineInClosureShim { .. } | InstanceDef::CoroutineKindShim { .. } | InstanceDef::DropGlue(..) + | InstanceDef::AsyncDropGlueCtorShim(..) | InstanceDef::CloneShim(..) | InstanceDef::FnPtrAddrShim(..) => return Visibility::Hidden, }; diff --git a/compiler/rustc_smir/src/rustc_smir/context.rs b/compiler/rustc_smir/src/rustc_smir/context.rs index 61bbedf9eec..fd31c020f89 100644 --- a/compiler/rustc_smir/src/rustc_smir/context.rs +++ b/compiler/rustc_smir/src/rustc_smir/context.rs @@ -500,6 +500,12 @@ impl<'tcx> Context for TablesWrapper<'tcx> { matches!(instance.def, ty::InstanceDef::DropGlue(_, None)) } + fn is_empty_async_drop_ctor_shim(&self, def: InstanceDef) -> bool { + let tables = self.0.borrow_mut(); + let instance = tables.instances[def]; + matches!(instance.def, ty::InstanceDef::AsyncDropGlueCtorShim(_, None)) + } + fn mono_instance(&self, def_id: stable_mir::DefId) -> stable_mir::mir::mono::Instance { let mut tables = self.0.borrow_mut(); let def_id = tables[def_id]; diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs index 112e44f674e..4abf991fba2 100644 --- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs +++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs @@ -807,7 +807,10 @@ impl<'tcx> Stable<'tcx> for ty::Instance<'tcx> { | ty::InstanceDef::ThreadLocalShim(..) | ty::InstanceDef::DropGlue(..) | ty::InstanceDef::CloneShim(..) - | ty::InstanceDef::FnPtrShim(..) => stable_mir::mir::mono::InstanceKind::Shim, + | ty::InstanceDef::FnPtrShim(..) + | ty::InstanceDef::AsyncDropGlueCtorShim(..) => { + stable_mir::mir::mono::InstanceKind::Shim + } }; stable_mir::mir::mono::Instance { def, kind } } diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index f5eeb3d4ff1..2d3053ccee6 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -425,6 +425,16 @@ symbols! { async_call_mut, async_call_once, async_closure, + async_destruct, + async_drop, + async_drop_chain, + async_drop_defer, + async_drop_either, + async_drop_fuse, + async_drop_in_place, + async_drop_noop, + async_drop_slice, + async_drop_surface_drop_in_place, async_fn, async_fn_in_trait, async_fn_kind_helper, @@ -826,6 +836,7 @@ symbols! { fadd_fast, fake_variadic, fallback, + fallback_surface_drop, fdiv_algebraic, fdiv_fast, feature, @@ -1789,6 +1800,7 @@ symbols! { sub_assign, sub_with_overflow, suggestion, + surface_async_drop_in_place, sym, sync, synthetic, diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs index f68668a91e6..f1c3512315f 100644 --- a/compiler/rustc_symbol_mangling/src/legacy.rs +++ b/compiler/rustc_symbol_mangling/src/legacy.rs @@ -55,7 +55,9 @@ pub(super) fn mangle<'tcx>( printer .print_def_path( def_id, - if let ty::InstanceDef::DropGlue(_, _) = instance.def { + if let ty::InstanceDef::DropGlue(_, _) | ty::InstanceDef::AsyncDropGlueCtorShim(_, _) = + instance.def + { // Add the name of the dropped type to the symbol name &*instance.args } else { diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs index 8b5c029428c..68b0db21141 100644 --- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs @@ -240,6 +240,11 @@ pub(super) trait GoalKind<'tcx>: goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx>; + fn consider_builtin_async_destruct_candidate( + ecx: &mut EvalCtxt<'_, 'tcx>, + goal: Goal<'tcx, Self>, + ) -> QueryResult<'tcx>; + fn consider_builtin_destruct_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, @@ -520,6 +525,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { G::consider_builtin_coroutine_candidate(self, goal) } else if lang_items.discriminant_kind_trait() == Some(trait_def_id) { G::consider_builtin_discriminant_kind_candidate(self, goal) + } else if lang_items.async_destruct_trait() == Some(trait_def_id) { + G::consider_builtin_async_destruct_candidate(self, goal) } else if lang_items.destruct_trait() == Some(trait_def_id) { G::consider_builtin_destruct_candidate(self, goal) } else if lang_items.transmute_trait() == Some(trait_def_id) { diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs index ebf2a0d9621..c662ab23c53 100644 --- a/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs @@ -814,6 +814,59 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> { }) } + fn consider_builtin_async_destruct_candidate( + ecx: &mut EvalCtxt<'_, 'tcx>, + goal: Goal<'tcx, Self>, + ) -> QueryResult<'tcx> { + let self_ty = goal.predicate.self_ty(); + let async_destructor_ty = match *self_ty.kind() { + ty::Bool + | ty::Char + | ty::Int(..) + | ty::Uint(..) + | ty::Float(..) + | ty::Array(..) + | ty::RawPtr(..) + | ty::Ref(..) + | ty::FnDef(..) + | ty::FnPtr(..) + | ty::Closure(..) + | ty::CoroutineClosure(..) + | ty::Infer(ty::IntVar(..) | ty::FloatVar(..)) + | ty::Never + | ty::Adt(_, _) + | ty::Str + | ty::Slice(_) + | ty::Tuple(_) + | ty::Error(_) => self_ty.async_destructor_ty(ecx.tcx(), goal.param_env), + + // We do not call `Ty::async_destructor_ty` on alias, param, or placeholder + // types, which return `<self_ty as AsyncDestruct>::AsyncDestructor` + // (or ICE in the case of placeholders). Projecting a type to itself + // is never really productive. + ty::Alias(_, _) | ty::Param(_) | ty::Placeholder(..) => { + return Err(NoSolution); + } + + ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) + | ty::Foreign(..) + | ty::Bound(..) => bug!( + "unexpected self ty `{:?}` when normalizing `<T as AsyncDestruct>::AsyncDestructor`", + goal.predicate.self_ty() + ), + + ty::Pat(..) | ty::Dynamic(..) | ty::Coroutine(..) | ty::CoroutineWitness(..) => bug!( + "`consider_builtin_async_destruct_candidate` is not yet implemented for type: {self_ty:?}" + ), + }; + + ecx.probe_misc_candidate("builtin async destruct").enter(|ecx| { + ecx.eq(goal.param_env, goal.predicate.term, async_destructor_ty.into()) + .expect("expected goal term to be fully unconstrained"); + ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) + }) + } + fn consider_builtin_destruct_candidate( _ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs index e522339358a..ed76ea74f08 100644 --- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs +++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs @@ -544,6 +544,18 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } + fn consider_builtin_async_destruct_candidate( + ecx: &mut EvalCtxt<'_, 'tcx>, + goal: Goal<'tcx, Self>, + ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::PredicatePolarity::Positive { + return Err(NoSolution); + } + + // `AsyncDestruct` is automatically implemented for every type. + ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) + } + fn consider_builtin_destruct_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index ca0b50864a8..116e17c7e43 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -1074,6 +1074,42 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( | ty::Infer(..) | ty::Error(_) => false, } + } else if lang_items.async_destruct_trait() == Some(trait_ref.def_id) { + match self_ty.kind() { + ty::Bool + | ty::Char + | ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Adt(..) + | ty::Str + | ty::Array(..) + | ty::Slice(_) + | ty::RawPtr(..) + | ty::Ref(..) + | ty::FnDef(..) + | ty::FnPtr(..) + | ty::Dynamic(..) + | ty::Closure(..) + | ty::CoroutineClosure(..) + | ty::Coroutine(..) + | ty::CoroutineWitness(..) + | ty::Pat(..) + | ty::Never + | ty::Tuple(..) + | ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(..)) => true, + + // type parameters, opaques, and unnormalized projections don't have + // a known async destructor and may need to be normalized further or rely + // on param env for async destructor projections + ty::Param(_) + | ty::Foreign(_) + | ty::Alias(..) + | ty::Bound(..) + | ty::Placeholder(..) + | ty::Infer(_) + | ty::Error(_) => false, + } } else if lang_items.pointee_trait() == Some(trait_ref.def_id) { let tail = selcx.tcx().struct_tail_with_normalize( self_ty, @@ -1488,15 +1524,20 @@ fn confirm_builtin_candidate<'cx, 'tcx>( ) -> Progress<'tcx> { let tcx = selcx.tcx(); let self_ty = obligation.predicate.self_ty(); - let args = tcx.mk_args(&[self_ty.into()]); let lang_items = tcx.lang_items(); let item_def_id = obligation.predicate.def_id; let trait_def_id = tcx.trait_of_item(item_def_id).unwrap(); + let args = tcx.mk_args(&[self_ty.into()]); let (term, obligations) = if lang_items.discriminant_kind_trait() == Some(trait_def_id) { let discriminant_def_id = tcx.require_lang_item(LangItem::Discriminant, None); assert_eq!(discriminant_def_id, item_def_id); (self_ty.discriminant_ty(tcx).into(), Vec::new()) + } else if lang_items.async_destruct_trait() == Some(trait_def_id) { + let destructor_def_id = tcx.associated_item_def_ids(trait_def_id)[0]; + assert_eq!(destructor_def_id, item_def_id); + + (self_ty.async_destructor_ty(tcx, obligation.param_env).into(), Vec::new()) } else if lang_items.pointee_trait() == Some(trait_def_id) { let metadata_def_id = tcx.require_lang_item(LangItem::Metadata, None); assert_eq!(metadata_def_id, item_def_id); diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index c415d288b8f..40d206b92b8 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -81,6 +81,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } else if lang_items.discriminant_kind_trait() == Some(def_id) { // `DiscriminantKind` is automatically implemented for every type. candidates.vec.push(BuiltinCandidate { has_nested: false }); + } else if lang_items.async_destruct_trait() == Some(def_id) { + // `AsyncDestruct` is automatically implemented for every type. + candidates.vec.push(BuiltinCandidate { has_nested: false }); } else if lang_items.pointee_trait() == Some(def_id) { // `Pointee` is automatically implemented for every type. candidates.vec.push(BuiltinCandidate { has_nested: false }); diff --git a/compiler/rustc_ty_utils/src/common_traits.rs b/compiler/rustc_ty_utils/src/common_traits.rs index 51b908881eb..cb95239e991 100644 --- a/compiler/rustc_ty_utils/src/common_traits.rs +++ b/compiler/rustc_ty_utils/src/common_traits.rs @@ -22,6 +22,17 @@ fn is_unpin_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) is_item_raw(tcx, query, LangItem::Unpin) } +fn has_surface_async_drop_raw<'tcx>( + tcx: TyCtxt<'tcx>, + query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>, +) -> bool { + is_item_raw(tcx, query, LangItem::AsyncDrop) +} + +fn has_surface_drop_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool { + is_item_raw(tcx, query, LangItem::Drop) +} + fn is_item_raw<'tcx>( tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>, @@ -34,5 +45,13 @@ fn is_item_raw<'tcx>( } pub(crate) fn provide(providers: &mut Providers) { - *providers = Providers { is_copy_raw, is_sized_raw, is_freeze_raw, is_unpin_raw, ..*providers }; + *providers = Providers { + is_copy_raw, + is_sized_raw, + is_freeze_raw, + is_unpin_raw, + has_surface_async_drop_raw, + has_surface_drop_raw, + ..*providers + }; } diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs index a8f9afb87dd..c1661fa63a8 100644 --- a/compiler/rustc_ty_utils/src/instance.rs +++ b/compiler/rustc_ty_utils/src/instance.rs @@ -54,6 +54,28 @@ fn resolve_instance<'tcx>( debug!(" => trivial drop glue"); ty::InstanceDef::DropGlue(def_id, None) } + } else if Some(def_id) == tcx.lang_items().async_drop_in_place_fn() { + let ty = args.type_at(0); + + if !ty.is_async_destructor_noop(tcx, param_env) { + match *ty.kind() { + ty::Closure(..) + | ty::CoroutineClosure(..) + | ty::Coroutine(..) + | ty::Tuple(..) + | ty::Adt(..) + | ty::Dynamic(..) + | ty::Array(..) + | ty::Slice(..) => {} + // Async destructor ctor shims can only be built from ADTs. + _ => return Ok(None), + } + debug!(" => nontrivial async drop glue ctor"); + ty::InstanceDef::AsyncDropGlueCtorShim(def_id, Some(ty)) + } else { + debug!(" => trivial async drop glue ctor"); + ty::InstanceDef::AsyncDropGlueCtorShim(def_id, None) + } } else { debug!(" => free item"); // FIXME(effects): we may want to erase the effect param if that is present on this item. diff --git a/compiler/stable_mir/src/compiler_interface.rs b/compiler/stable_mir/src/compiler_interface.rs index 94c552199bc..e82d1f4813e 100644 --- a/compiler/stable_mir/src/compiler_interface.rs +++ b/compiler/stable_mir/src/compiler_interface.rs @@ -158,6 +158,9 @@ pub trait Context { /// Check if this is an empty DropGlue shim. fn is_empty_drop_shim(&self, def: InstanceDef) -> bool; + /// Check if this is an empty AsyncDropGlueCtor shim. + fn is_empty_async_drop_ctor_shim(&self, def: InstanceDef) -> bool; + /// Convert a non-generic crate item into an instance. /// This function will panic if the item is generic. fn mono_instance(&self, def_id: DefId) -> Instance; diff --git a/compiler/stable_mir/src/mir/mono.rs b/compiler/stable_mir/src/mir/mono.rs index a032a180fcf..394038926f6 100644 --- a/compiler/stable_mir/src/mir/mono.rs +++ b/compiler/stable_mir/src/mir/mono.rs @@ -157,7 +157,10 @@ impl Instance { /// When generating code for a Drop terminator, users can ignore an empty drop glue. /// These shims are only needed to generate a valid Drop call done via VTable. pub fn is_empty_shim(&self) -> bool { - self.kind == InstanceKind::Shim && with(|cx| cx.is_empty_drop_shim(self.def)) + self.kind == InstanceKind::Shim + && with(|cx| { + cx.is_empty_drop_shim(self.def) || cx.is_empty_async_drop_ctor_shim(self.def) + }) } /// Try to constant evaluate the instance into a constant with the given type. |