diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/shim.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/shim.rs | 377 |
1 files changed, 267 insertions, 110 deletions
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index eaa61d8614d..5f12f1937c0 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -2,12 +2,12 @@ use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_hir::lang_items::LangItem; use rustc_middle::mir::*; -use rustc_middle::ty::query::Providers; -use rustc_middle::ty::subst::{InternalSubsts, Subst}; -use rustc_middle::ty::{self, EarlyBinder, Ty, TyCtxt}; -use rustc_target::abi::VariantIdx; +use rustc_middle::query::Providers; +use rustc_middle::ty::InternalSubsts; +use rustc_middle::ty::{self, EarlyBinder, GeneratorSubsts, Ty, TyCtxt}; +use rustc_target::abi::{FieldIdx, VariantIdx, FIRST_VARIANT}; -use rustc_index::vec::{Idx, IndexVec}; +use rustc_index::{Idx, IndexVec}; use rustc_span::Span; use rustc_target::spec::abi::Abi; @@ -15,10 +15,9 @@ use rustc_target::spec::abi::Abi; use std::fmt; use std::iter; -use crate::util::expand_aggregate; use crate::{ - abort_unwinding_calls, add_call_guards, add_moves_for_packed_drops, marker, pass_manager as pm, - remove_noop_landing_pads, simplify, + abort_unwinding_calls, add_call_guards, add_moves_for_packed_drops, deref_separator, + pass_manager as pm, remove_noop_landing_pads, simplify, }; use rustc_middle::mir::patch::MirPatch; use rustc_mir_dataflow::elaborate_drops::{self, DropElaborator, DropFlagMode, DropStyle}; @@ -32,12 +31,12 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<' let mut result = match instance { ty::InstanceDef::Item(..) => bug!("item {:?} passed to make_shim", instance), - ty::InstanceDef::VtableShim(def_id) => { + ty::InstanceDef::VTableShim(def_id) => { build_call_shim(tcx, instance, Some(Adjustment::Deref), CallKind::Direct(def_id)) } ty::InstanceDef::FnPtrShim(def_id, ty) => { let trait_ = tcx.trait_of_item(def_id).unwrap(); - let adjustment = match tcx.fn_trait_kind_from_lang_item(trait_) { + let adjustment = match tcx.fn_trait_kind_from_def_id(trait_) { Some(ty::ClosureKind::FnOnce) => Adjustment::Identity, Some(ty::ClosureKind::FnMut | ty::ClosureKind::Fn) => Adjustment::Deref, None => bug!("fn pointer {:?} is not an fn", ty), @@ -70,14 +69,16 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<' // of this function. Is this intentional? if let Some(ty::Generator(gen_def_id, substs, _)) = ty.map(Ty::kind) { let body = tcx.optimized_mir(*gen_def_id).generator_drop().unwrap(); - let body = EarlyBinder(body.clone()).subst(tcx, substs); + let body = EarlyBinder::bind(body.clone()).subst(tcx, substs); debug!("make_shim({:?}) = {:?}", instance, body); return body; } build_drop_shim(tcx, def_id, ty) } + 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::Virtual(..) => { bug!("InstanceDef::Virtual ({:?}) is for direct calls only", instance) } @@ -92,12 +93,13 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<' &mut result, &[ &add_moves_for_packed_drops::AddMovesForPackedDrops, + &deref_separator::Derefer, &remove_noop_landing_pads::RemoveNoopLandingPads, - &simplify::SimplifyCfg::new("make_shim"), + &simplify::SimplifyCfg::MakeShim, &add_call_guards::CriticalCallEdges, &abort_unwinding_calls::AbortUnwindingCalls, - &marker::PhaseChange(MirPhase::Const), ], + Some(MirPhase::Runtime(RuntimePhase::Optimized)), ); debug!("make_shim({:?}) = {:?}", instance, result); @@ -113,7 +115,7 @@ enum Adjustment { /// We get passed `&[mut] self` and call the target with `*self`. /// /// This either copies `self` (if `Self: Copy`, eg. for function items), or moves out of it - /// (for `VtableShim`, which effectively is passed `&own Self`). + /// (for `VTableShim`, which effectively is passed `&own Self`). Deref, /// We get passed `self: Self` and call the target with `&mut self`. @@ -147,11 +149,11 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) assert!(!matches!(ty, Some(ty) if ty.is_generator())); let substs = if let Some(ty) = ty { - tcx.intern_substs(&[ty.into()]) + tcx.mk_substs(&[ty.into()]) } else { InternalSubsts::identity_for_item(tcx, def_id) }; - let sig = tcx.bound_fn_sig(def_id).subst(tcx, substs); + let sig = tcx.fn_sig(def_id).subst(tcx, substs); let sig = tcx.erase_late_bound_regions(sig); let span = tcx.def_span(def_id); @@ -173,19 +175,36 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) let mut body = new_body(source, blocks, local_decls_for_sig(&sig, span), sig.inputs().len(), span); - if ty.is_some() { - // The first argument (index 0), but add 1 for the return value. - let dropee_ptr = Place::from(Local::new(1 + 0)); - if tcx.sess.opts.unstable_opts.mir_emit_retag { - // Function arguments should be retagged, and we make this one raw. - body.basic_blocks_mut()[START_BLOCK].statements.insert( - 0, - Statement { - source_info, - kind: StatementKind::Retag(RetagKind::Raw, Box::new(dropee_ptr)), - }, - ); + // The first argument (index 0), but add 1 for the return value. + let mut dropee_ptr = Place::from(Local::new(1 + 0)); + if tcx.sess.opts.unstable_opts.mir_emit_retag { + // We want to treat the function argument as if it was passed by `&mut`. As such, we + // generate + // ``` + // temp = &mut *arg; + // Retag(temp, FnEntry) + // ``` + // It's important that we do this first, before anything that depends on `dropee_ptr` + // has been put into the body. + let reborrow = Rvalue::Ref( + tcx.lifetimes.re_erased, + BorrowKind::Mut { allow_two_phase_borrow: false }, + tcx.mk_place_deref(dropee_ptr), + ); + let ref_ty = reborrow.ty(body.local_decls(), tcx); + dropee_ptr = body.local_decls.push(LocalDecl::new(ref_ty, span)).into(); + let new_statements = [ + StatementKind::Assign(Box::new((dropee_ptr, reborrow))), + StatementKind::Retag(RetagKind::FnEntry, Box::new(dropee_ptr)), + ]; + for s in new_statements { + body.basic_blocks_mut()[START_BLOCK] + .statements + .push(Statement { source_info, kind: s }); } + } + + if ty.is_some() { let patch = { let param_env = tcx.param_env_reveal_all_normalized(def_id); let mut elaborator = @@ -290,7 +309,7 @@ impl<'a, 'tcx> DropElaborator<'a, 'tcx> for DropShimElaborator<'a, 'tcx> { fn clear_drop_flag(&mut self, _location: Location, _path: Self::Path, _mode: DropFlagMode) {} - fn field_subpath(&self, _path: Self::Path, _field: Field) -> Option<Self::Path> { + fn field_subpath(&self, _path: Self::Path, _field: FieldIdx) -> Option<Self::Path> { None } fn deref_subpath(&self, _path: Self::Path) -> Option<Self::Path> { @@ -304,14 +323,42 @@ impl<'a, 'tcx> DropElaborator<'a, 'tcx> for DropShimElaborator<'a, 'tcx> { } } +fn build_thread_local_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<'tcx> { + let def_id = instance.def_id(); + + let span = tcx.def_span(def_id); + let source_info = SourceInfo::outermost(span); + + let mut blocks = IndexVec::with_capacity(1); + blocks.push(BasicBlockData { + statements: vec![Statement { + source_info, + kind: StatementKind::Assign(Box::new(( + Place::return_place(), + Rvalue::ThreadLocalRef(def_id), + ))), + }], + terminator: Some(Terminator { source_info, kind: TerminatorKind::Return }), + is_cleanup: false, + }); + + new_body( + MirSource::from_instance(instance), + blocks, + IndexVec::from_raw(vec![LocalDecl::new(tcx.thread_local_ptr_ty(def_id), span)]), + 0, + span, + ) +} + /// Builds a `Clone::clone` shim for `self_ty`. Here, `def_id` is `Clone::clone`. fn build_clone_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Body<'tcx> { debug!("build_clone_shim(def_id={:?})", def_id); - let param_env = tcx.param_env(def_id); + let param_env = tcx.param_env_reveal_all_normalized(def_id); let mut builder = CloneShimBuilder::new(tcx, def_id, self_ty); - let is_copy = self_ty.is_copy_modulo_regions(tcx.at(builder.span), param_env); + let is_copy = self_ty.is_copy_modulo_regions(tcx, param_env); let dest = Place::return_place(); let src = tcx.mk_place_deref(Place::from(Local::new(1 + 0))); @@ -322,6 +369,9 @@ fn build_clone_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) - builder.tuple_like_shim(dest, src, substs.as_closure().upvar_tys()) } ty::Tuple(..) => builder.tuple_like_shim(dest, src, self_ty.tuple_fields()), + ty::Generator(gen_def_id, substs, hir::Movability::Movable) => { + builder.generator_shim(dest, src, *gen_def_id, substs.as_generator()) + } _ => bug!("clone shim for `{:?}` which is not `Copy` and is not an aggregate", self_ty), }; @@ -342,8 +392,7 @@ impl<'tcx> CloneShimBuilder<'tcx> { // we must subst the self_ty because it's // otherwise going to be TySelf and we can't index // or access fields of a Place of type TySelf. - let substs = tcx.mk_substs_trait(self_ty, &[]); - let sig = tcx.bound_fn_sig(def_id).subst(tcx, substs); + let sig = tcx.fn_sig(def_id).subst(tcx, &[self_ty.into()]); let sig = tcx.erase_late_bound_regions(sig); let span = tcx.def_span(def_id); @@ -387,7 +436,7 @@ impl<'tcx> CloneShimBuilder<'tcx> { /// offset=0 will give you the index of the next BasicBlock, /// offset=1 will give the index of the next-to-next block, /// offset=-1 will give you the index of the last-created block - fn block_index_offset(&mut self, offset: usize) -> BasicBlock { + fn block_index_offset(&self, offset: usize) -> BasicBlock { BasicBlock::new(self.blocks.len() + offset) } @@ -407,7 +456,7 @@ impl<'tcx> CloneShimBuilder<'tcx> { fn make_place(&mut self, mutability: Mutability, ty: Ty<'tcx>) -> Place<'tcx> { let span = self.span; let mut local = LocalDecl::new(ty, span); - if mutability == Mutability::Not { + if mutability.is_not() { local = local.immutable(); } Place::from(self.local_decls.push(local)) @@ -423,10 +472,8 @@ impl<'tcx> CloneShimBuilder<'tcx> { ) { let tcx = self.tcx; - let substs = tcx.mk_substs_trait(ty, &[]); - // `func == Clone::clone(&ty) -> ty` - let func_ty = tcx.mk_fn_def(self.def_id, substs); + let func_ty = tcx.mk_fn_def(self.def_id, [ty]); let func = Operand::Constant(Box::new(Constant { span: self.span, user_ty: None, @@ -452,7 +499,7 @@ impl<'tcx> CloneShimBuilder<'tcx> { args: vec![Operand::Move(ref_loc)], destination: dest, target: Some(next), - cleanup: Some(cleanup), + unwind: UnwindAction::Cleanup(cleanup), from_hir_call: true, fn_span: self.span, }, @@ -460,65 +507,122 @@ impl<'tcx> CloneShimBuilder<'tcx> { ); } - fn tuple_like_shim<I>(&mut self, dest: Place<'tcx>, src: Place<'tcx>, tys: I) + fn clone_fields<I>( + &mut self, + dest: Place<'tcx>, + src: Place<'tcx>, + target: BasicBlock, + mut unwind: BasicBlock, + tys: I, + ) -> BasicBlock where I: IntoIterator<Item = Ty<'tcx>>, { - let mut previous_field = None; + // For an iterator of length n, create 2*n + 1 blocks. for (i, ity) in tys.into_iter().enumerate() { - let field = Field::new(i); + // Each iteration creates two blocks, referred to here as block 2*i and block 2*i + 1. + // + // Block 2*i attempts to clone the field. If successful it branches to 2*i + 2 (the + // next clone block). If unsuccessful it branches to the previous unwind block, which + // is initially the `unwind` argument passed to this function. + // + // Block 2*i + 1 is the unwind block for this iteration. It drops the cloned value + // created by block 2*i. We store this block in `unwind` so that the next clone block + // will unwind to it if cloning fails. + + let field = FieldIdx::new(i); let src_field = self.tcx.mk_place_field(src, field, ity); let dest_field = self.tcx.mk_place_field(dest, field, ity); - // #(2i + 1) is the cleanup block for the previous clone operation - let cleanup_block = self.block_index_offset(1); - // #(2i + 2) is the next cloning block - // (or the Return terminator if this is the last block) + let next_unwind = self.block_index_offset(1); let next_block = self.block_index_offset(2); + self.make_clone_call(dest_field, src_field, ity, next_block, unwind); + self.block( + vec![], + TerminatorKind::Drop { + place: dest_field, + target: unwind, + unwind: UnwindAction::Terminate, + replace: false, + }, + true, + ); + unwind = next_unwind; + } + // If all clones succeed then we end up here. + self.block(vec![], TerminatorKind::Goto { target }, false); + unwind + } - // BB #(2i) - // `dest.i = Clone::clone(&src.i);` - // Goto #(2i + 2) if ok, #(2i + 1) if unwinding happens. - self.make_clone_call(dest_field, src_field, ity, next_block, cleanup_block); - - // BB #(2i + 1) (cleanup) - if let Some((previous_field, previous_cleanup)) = previous_field.take() { - // Drop previous field and goto previous cleanup block. - self.block( - vec![], - TerminatorKind::Drop { - place: previous_field, - target: previous_cleanup, - unwind: None, - }, - true, - ); - } else { - // Nothing to drop, just resume. - self.block(vec![], TerminatorKind::Resume, true); - } + fn tuple_like_shim<I>(&mut self, dest: Place<'tcx>, src: Place<'tcx>, tys: I) + where + I: IntoIterator<Item = Ty<'tcx>>, + { + self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false); + let unwind = self.block(vec![], TerminatorKind::Resume, true); + let target = self.block(vec![], TerminatorKind::Return, false); - previous_field = Some((dest_field, cleanup_block)); - } + let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, tys); + } - self.block(vec![], TerminatorKind::Return, false); + fn generator_shim( + &mut self, + dest: Place<'tcx>, + src: Place<'tcx>, + gen_def_id: DefId, + substs: GeneratorSubsts<'tcx>, + ) { + self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false); + let unwind = self.block(vec![], TerminatorKind::Resume, true); + // This will get overwritten with a switch once we know the target blocks + let switch = self.block(vec![], TerminatorKind::Unreachable, false); + let unwind = self.clone_fields(dest, src, switch, unwind, substs.upvar_tys()); + let target = self.block(vec![], TerminatorKind::Return, false); + let unreachable = self.block(vec![], TerminatorKind::Unreachable, false); + let mut cases = Vec::with_capacity(substs.state_tys(gen_def_id, self.tcx).count()); + for (index, state_tys) in substs.state_tys(gen_def_id, self.tcx).enumerate() { + let variant_index = VariantIdx::new(index); + let dest = self.tcx.mk_place_downcast_unnamed(dest, variant_index); + let src = self.tcx.mk_place_downcast_unnamed(src, variant_index); + let clone_block = self.block_index_offset(1); + let start_block = self.block( + vec![self.make_statement(StatementKind::SetDiscriminant { + place: Box::new(Place::return_place()), + variant_index, + })], + TerminatorKind::Goto { target: clone_block }, + false, + ); + cases.push((index as u128, start_block)); + let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, state_tys); + } + let discr_ty = substs.discr_ty(self.tcx); + let temp = self.make_place(Mutability::Mut, discr_ty); + let rvalue = Rvalue::Discriminant(src); + let statement = self.make_statement(StatementKind::Assign(Box::new((temp, rvalue)))); + match &mut self.blocks[switch] { + BasicBlockData { statements, terminator: Some(Terminator { kind, .. }), .. } => { + statements.push(statement); + *kind = TerminatorKind::SwitchInt { + discr: Operand::Move(temp), + targets: SwitchTargets::new(cases.into_iter(), unreachable), + }; + } + BasicBlockData { terminator: None, .. } => unreachable!(), + } } } /// Builds a "call" shim for `instance`. The shim calls the function specified by `call_kind`, /// first adjusting its first argument according to `rcvr_adjustment`. +#[instrument(level = "debug", skip(tcx), ret)] fn build_call_shim<'tcx>( tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>, rcvr_adjustment: Option<Adjustment>, call_kind: CallKind<'tcx>, ) -> Body<'tcx> { - debug!( - "build_call_shim(instance={:?}, rcvr_adjustment={:?}, call_kind={:?})", - instance, rcvr_adjustment, call_kind - ); - // `FnPtrShim` contains the fn pointer type that a call shim is being built for - this is used // to substitute into the signature of the shim. It is not necessary for users of this // MIR body to perform further substitutions (see `InstanceDef::has_polymorphic_mir_body`). @@ -528,21 +632,23 @@ fn build_call_shim<'tcx>( let untuple_args = sig.inputs(); // Create substitutions for the `Self` and `Args` generic parameters of the shim body. - let arg_tup = tcx.mk_tup(untuple_args.iter()); - let sig_substs = tcx.mk_substs_trait(ty, &[ty::subst::GenericArg::from(arg_tup)]); + let arg_tup = tcx.mk_tup(untuple_args); - (Some(sig_substs), Some(untuple_args)) + (Some([ty.into(), arg_tup.into()]), Some(untuple_args)) } else { (None, None) }; let def_id = instance.def_id(); - let sig = tcx.bound_fn_sig(def_id); + let sig = tcx.fn_sig(def_id); let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig)); assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body()); - let mut sig = - if let Some(sig_substs) = sig_substs { sig.subst(tcx, sig_substs) } else { sig.0 }; + let mut sig = if let Some(sig_substs) = sig_substs { + sig.subst(tcx, &sig_substs) + } else { + sig.subst_identity() + }; if let CallKind::Indirect(fnty) = call_kind { // `sig` determines our local decls, and thus the callee type in the `Call` terminator. This @@ -564,23 +670,23 @@ fn build_call_shim<'tcx>( Adjustment::Deref => tcx.mk_imm_ptr(fnty), Adjustment::RefMut => tcx.mk_mut_ptr(fnty), }; - sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output); + sig.inputs_and_output = tcx.mk_type_list(&inputs_and_output); } // FIXME(eddyb) avoid having this snippet both here and in // `Instance::fn_sig` (introduce `InstanceDef::fn_sig`?). - if let ty::InstanceDef::VtableShim(..) = instance { + if let ty::InstanceDef::VTableShim(..) = instance { // Modify fn(self, ...) to fn(self: *mut Self, ...) let mut inputs_and_output = sig.inputs_and_output.to_vec(); let self_arg = &mut inputs_and_output[0]; debug_assert!(tcx.generics_of(def_id).has_self && *self_arg == tcx.types.self_param); *self_arg = tcx.mk_mut_ptr(*self_arg); - sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output); + sig.inputs_and_output = tcx.mk_type_list(&inputs_and_output); } let span = tcx.def_span(def_id); - debug!("build_call_shim: sig={:?}", sig); + debug!(?sig); let mut local_decls = local_decls_for_sig(&sig, span); let source_info = SourceInfo::outermost(span); @@ -624,7 +730,7 @@ fn build_call_shim<'tcx>( // `FnDef` call with optional receiver. CallKind::Direct(def_id) => { - let ty = tcx.type_of(def_id); + let ty = tcx.type_of(def_id).subst_identity(); ( Operand::Constant(Box::new(Constant { span, @@ -655,7 +761,7 @@ fn build_call_shim<'tcx>( if let Some(untuple_args) = untuple_args { let tuple_arg = Local::new(1 + (sig.inputs().len() - 1)); args.extend(untuple_args.iter().enumerate().map(|(i, ity)| { - Operand::Move(tcx.mk_place_field(Place::from(tuple_arg), Field::new(i), *ity)) + Operand::Move(tcx.mk_place_field(Place::from(tuple_arg), FieldIdx::new(i), *ity)) })); } @@ -678,10 +784,10 @@ fn build_call_shim<'tcx>( args, destination: Place::return_place(), target: Some(BasicBlock::new(1)), - cleanup: if let Some(Adjustment::RefMut) = rcvr_adjustment { - Some(BasicBlock::new(3)) + unwind: if let Some(Adjustment::RefMut) = rcvr_adjustment { + UnwindAction::Cleanup(BasicBlock::new(3)) } else { - None + UnwindAction::Continue }, from_hir_call: true, fn_span: span, @@ -694,7 +800,12 @@ fn build_call_shim<'tcx>( block( &mut blocks, vec![], - TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(2), unwind: None }, + TerminatorKind::Drop { + place: rcvr_place(), + target: BasicBlock::new(2), + unwind: UnwindAction::Continue, + replace: false, + }, false, ); } @@ -705,7 +816,12 @@ fn build_call_shim<'tcx>( block( &mut blocks, vec![], - TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(4), unwind: None }, + TerminatorKind::Drop { + place: rcvr_place(), + target: BasicBlock::new(4), + unwind: UnwindAction::Terminate, + replace: false, + }, true, ); @@ -726,10 +842,14 @@ fn build_call_shim<'tcx>( pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> { debug_assert!(tcx.is_constructor(ctor_id)); - let param_env = tcx.param_env(ctor_id); + let param_env = tcx.param_env_reveal_all_normalized(ctor_id); // Normalize the sig. - let sig = tcx.fn_sig(ctor_id).no_bound_vars().expect("LBR in ADT constructor signature"); + let sig = tcx + .fn_sig(ctor_id) + .subst_identity() + .no_bound_vars() + .expect("LBR in ADT constructor signature"); let sig = tcx.normalize_erasing_regions(param_env, sig); let ty::Adt(adt_def, substs) = sig.output().kind() else { @@ -744,11 +864,8 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> { let source_info = SourceInfo::outermost(span); - let variant_index = if adt_def.is_enum() { - adt_def.variant_index_with_ctor_id(ctor_id) - } else { - VariantIdx::new(0) - }; + let variant_index = + if adt_def.is_enum() { adt_def.variant_index_with_ctor_id(ctor_id) } else { FIRST_VARIANT }; // Generate the following MIR: // @@ -758,19 +875,23 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> { // return; debug!("build_ctor: variant_index={:?}", variant_index); - let statements = expand_aggregate( - Place::return_place(), - adt_def.variant(variant_index).fields.iter().enumerate().map(|(idx, field_def)| { - (Operand::Move(Place::from(Local::new(idx + 1))), field_def.ty(tcx, substs)) - }), - AggregateKind::Adt(adt_def.did(), variant_index, substs, None, None), + let kind = AggregateKind::Adt(adt_def.did(), variant_index, substs, None, None); + let variant = adt_def.variant(variant_index); + let statement = Statement { + kind: StatementKind::Assign(Box::new(( + Place::return_place(), + Rvalue::Aggregate( + Box::new(kind), + (0..variant.fields.len()) + .map(|idx| Operand::Move(Place::from(Local::new(idx + 1)))) + .collect(), + ), + ))), source_info, - tcx, - ) - .collect(); + }; let start_block = BasicBlockData { - statements, + statements: vec![statement], terminator: Some(Terminator { source_info, kind: TerminatorKind::Return }), is_cleanup: false, }; @@ -784,7 +905,43 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> { span, ); - rustc_middle::mir::dump_mir(tcx, None, "mir_map", &0, &body, |_, _| Ok(())); + crate::pass_manager::dump_mir_for_phase_change(tcx, &body); body } + +/// ```ignore (pseudo-impl) +/// impl FnPtr for fn(u32) { +/// fn addr(self) -> usize { +/// self as usize +/// } +/// } +/// ``` +fn build_fn_ptr_addr_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Body<'tcx> { + assert!(matches!(self_ty.kind(), ty::FnPtr(..)), "expected fn ptr, found {self_ty}"); + let span = tcx.def_span(def_id); + let Some(sig) = tcx.fn_sig(def_id).subst(tcx, &[self_ty.into()]).no_bound_vars() else { + span_bug!(span, "FnPtr::addr with bound vars for `{self_ty}`"); + }; + let locals = local_decls_for_sig(&sig, span); + + let source_info = SourceInfo::outermost(span); + // FIXME: use `expose_addr` once we figure out whether function pointers have meaningful provenance. + let rvalue = Rvalue::Cast( + CastKind::FnPtrToPtr, + Operand::Move(Place::from(Local::new(1))), + tcx.mk_imm_ptr(tcx.types.unit), + ); + let stmt = Statement { + source_info, + kind: StatementKind::Assign(Box::new((Place::return_place(), rvalue))), + }; + let statements = vec![stmt]; + let start_block = BasicBlockData { + statements, + terminator: Some(Terminator { source_info, kind: TerminatorKind::Return }), + is_cleanup: false, + }; + let source = MirSource::from_instance(ty::InstanceDef::FnPtrAddrShim(def_id, self_ty)); + new_body(source, IndexVec::from_elem_n(start_block, 1), locals, sig.inputs().len(), span) +} |