2 use rustc_hir::def_id::DefId;
3 use rustc_hir::lang_items::LangItem;
4 use rustc_middle::mir::*;
5 use rustc_middle::ty::query::Providers;
6 use rustc_middle::ty::InternalSubsts;
7 use rustc_middle::ty::{self, EarlyBinder, GeneratorSubsts, Ty, TyCtxt};
8 use rustc_target::abi::VariantIdx;
10 use rustc_index::vec::{Idx, IndexVec};
13 use rustc_target::spec::abi::Abi;
18 use crate::util::expand_aggregate;
20 abort_unwinding_calls, add_call_guards, add_moves_for_packed_drops, deref_separator,
21 pass_manager as pm, remove_noop_landing_pads, simplify,
23 use rustc_middle::mir::patch::MirPatch;
24 use rustc_mir_dataflow::elaborate_drops::{self, DropElaborator, DropFlagMode, DropStyle};
26 pub fn provide(providers: &mut Providers) {
27 providers.mir_shims = make_shim;
30 fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<'tcx> {
31 debug!("make_shim({:?})", instance);
33 let mut result = match instance {
34 ty::InstanceDef::Item(..) => bug!("item {:?} passed to make_shim", instance),
35 ty::InstanceDef::VTableShim(def_id) => {
36 build_call_shim(tcx, instance, Some(Adjustment::Deref), CallKind::Direct(def_id))
38 ty::InstanceDef::FnPtrShim(def_id, ty) => {
39 let trait_ = tcx.trait_of_item(def_id).unwrap();
40 let adjustment = match tcx.fn_trait_kind_from_def_id(trait_) {
41 Some(ty::ClosureKind::FnOnce) => Adjustment::Identity,
42 Some(ty::ClosureKind::FnMut | ty::ClosureKind::Fn) => Adjustment::Deref,
43 None => bug!("fn pointer {:?} is not an fn", ty),
46 build_call_shim(tcx, instance, Some(adjustment), CallKind::Indirect(ty))
48 // We are generating a call back to our def-id, which the
49 // codegen backend knows to turn to an actual call, be it
50 // a virtual call, or a direct call to a function for which
51 // indirect calls must be codegen'd differently than direct ones
52 // (such as `#[track_caller]`).
53 ty::InstanceDef::ReifyShim(def_id) => {
54 build_call_shim(tcx, instance, None, CallKind::Direct(def_id))
56 ty::InstanceDef::ClosureOnceShim { call_once: _, track_caller: _ } => {
57 let fn_mut = tcx.require_lang_item(LangItem::FnMut, None);
59 .associated_items(fn_mut)
60 .in_definition_order()
61 .find(|it| it.kind == ty::AssocKind::Fn)
65 build_call_shim(tcx, instance, Some(Adjustment::RefMut), CallKind::Direct(call_mut))
68 ty::InstanceDef::DropGlue(def_id, ty) => {
69 // FIXME(#91576): Drop shims for generators aren't subject to the MIR passes at the end
70 // of this function. Is this intentional?
71 if let Some(ty::Generator(gen_def_id, substs, _)) = ty.map(Ty::kind) {
72 let body = tcx.optimized_mir(*gen_def_id).generator_drop().unwrap();
73 let body = EarlyBinder(body.clone()).subst(tcx, substs);
74 debug!("make_shim({:?}) = {:?}", instance, body);
78 build_drop_shim(tcx, def_id, ty)
80 ty::InstanceDef::CloneShim(def_id, ty) => build_clone_shim(tcx, def_id, ty),
81 ty::InstanceDef::Virtual(..) => {
82 bug!("InstanceDef::Virtual ({:?}) is for direct calls only", instance)
84 ty::InstanceDef::Intrinsic(_) => {
85 bug!("creating shims from intrinsics ({:?}) is unsupported", instance)
88 debug!("make_shim({:?}) = untransformed {:?}", instance, result);
94 &add_moves_for_packed_drops::AddMovesForPackedDrops,
95 &deref_separator::Derefer,
96 &remove_noop_landing_pads::RemoveNoopLandingPads,
97 &simplify::SimplifyCfg::new("make_shim"),
98 &add_call_guards::CriticalCallEdges,
99 &abort_unwinding_calls::AbortUnwindingCalls,
101 Some(MirPhase::Runtime(RuntimePhase::Optimized)),
104 debug!("make_shim({:?}) = {:?}", instance, result);
109 #[derive(Copy, Clone, Debug, PartialEq)]
111 /// Pass the receiver as-is.
114 /// We get passed `&[mut] self` and call the target with `*self`.
116 /// This either copies `self` (if `Self: Copy`, eg. for function items), or moves out of it
117 /// (for `VTableShim`, which effectively is passed `&own Self`).
120 /// We get passed `self: Self` and call the target with `&mut self`.
122 /// In this case we need to ensure that the `Self` is dropped after the call, as the callee
123 /// won't do it for us.
127 #[derive(Copy, Clone, Debug, PartialEq)]
128 enum CallKind<'tcx> {
129 /// Call the `FnPtr` that was passed as the receiver.
132 /// Call a known `FnDef`.
136 fn local_decls_for_sig<'tcx>(
137 sig: &ty::FnSig<'tcx>,
139 ) -> IndexVec<Local, LocalDecl<'tcx>> {
140 iter::once(LocalDecl::new(sig.output(), span))
141 .chain(sig.inputs().iter().map(|ity| LocalDecl::new(*ity, span).immutable()))
145 fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) -> Body<'tcx> {
146 debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty);
148 assert!(!matches!(ty, Some(ty) if ty.is_generator()));
150 let substs = if let Some(ty) = ty {
151 tcx.intern_substs(&[ty.into()])
153 InternalSubsts::identity_for_item(tcx, def_id)
155 let sig = tcx.bound_fn_sig(def_id).subst(tcx, substs);
156 let sig = tcx.erase_late_bound_regions(sig);
157 let span = tcx.def_span(def_id);
159 let source_info = SourceInfo::outermost(span);
161 let return_block = BasicBlock::new(1);
162 let mut blocks = IndexVec::with_capacity(2);
163 let block = |blocks: &mut IndexVec<_, _>, kind| {
164 blocks.push(BasicBlockData {
166 terminator: Some(Terminator { source_info, kind }),
170 block(&mut blocks, TerminatorKind::Goto { target: return_block });
171 block(&mut blocks, TerminatorKind::Return);
173 let source = MirSource::from_instance(ty::InstanceDef::DropGlue(def_id, ty));
175 new_body(source, blocks, local_decls_for_sig(&sig, span), sig.inputs().len(), span);
177 // The first argument (index 0), but add 1 for the return value.
178 let mut dropee_ptr = Place::from(Local::new(1 + 0));
179 if tcx.sess.opts.unstable_opts.mir_emit_retag {
180 // We want to treat the function argument as if it was passed by `&mut`. As such, we
184 // Retag(temp, FnEntry)
186 // It's important that we do this first, before anything that depends on `dropee_ptr`
187 // has been put into the body.
188 let reborrow = Rvalue::Ref(
189 tcx.lifetimes.re_erased,
190 BorrowKind::Mut { allow_two_phase_borrow: false },
191 tcx.mk_place_deref(dropee_ptr),
193 let ref_ty = reborrow.ty(body.local_decls(), tcx);
194 dropee_ptr = body.local_decls.push(LocalDecl::new(ref_ty, span)).into();
195 let new_statements = [
196 StatementKind::Assign(Box::new((dropee_ptr, reborrow))),
197 StatementKind::Retag(RetagKind::FnEntry, Box::new(dropee_ptr)),
199 for s in new_statements {
200 body.basic_blocks_mut()[START_BLOCK]
202 .push(Statement { source_info, kind: s });
208 let param_env = tcx.param_env_reveal_all_normalized(def_id);
210 DropShimElaborator { body: &body, patch: MirPatch::new(&body), tcx, param_env };
211 let dropee = tcx.mk_place_deref(dropee_ptr);
212 let resume_block = elaborator.patch.resume_block();
213 elaborate_drops::elaborate_drop(
219 elaborate_drops::Unwind::To(resume_block),
224 patch.apply(&mut body);
231 source: MirSource<'tcx>,
232 basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
233 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
240 IndexVec::from_elem_n(
245 inlined_parent_scope: None,
246 local_data: ClearCrossCrate::Clear,
256 // FIXME(compiler-errors): is this correct?
261 pub struct DropShimElaborator<'a, 'tcx> {
262 pub body: &'a Body<'tcx>,
263 pub patch: MirPatch<'tcx>,
264 pub tcx: TyCtxt<'tcx>,
265 pub param_env: ty::ParamEnv<'tcx>,
268 impl fmt::Debug for DropShimElaborator<'_, '_> {
269 fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
274 impl<'a, 'tcx> DropElaborator<'a, 'tcx> for DropShimElaborator<'a, 'tcx> {
277 fn patch(&mut self) -> &mut MirPatch<'tcx> {
280 fn body(&self) -> &'a Body<'tcx> {
283 fn tcx(&self) -> TyCtxt<'tcx> {
286 fn param_env(&self) -> ty::ParamEnv<'tcx> {
290 fn drop_style(&self, _path: Self::Path, mode: DropFlagMode) -> DropStyle {
292 DropFlagMode::Shallow => {
293 // Drops for the contained fields are "shallow" and "static" - they will simply call
294 // the field's own drop glue.
297 DropFlagMode::Deep => {
298 // The top-level drop is "deep" and "open" - it will be elaborated to a drop ladder
299 // dropping each field contained in the value.
305 fn get_drop_flag(&mut self, _path: Self::Path) -> Option<Operand<'tcx>> {
309 fn clear_drop_flag(&mut self, _location: Location, _path: Self::Path, _mode: DropFlagMode) {}
311 fn field_subpath(&self, _path: Self::Path, _field: Field) -> Option<Self::Path> {
314 fn deref_subpath(&self, _path: Self::Path) -> Option<Self::Path> {
317 fn downcast_subpath(&self, _path: Self::Path, _variant: VariantIdx) -> Option<Self::Path> {
320 fn array_subpath(&self, _path: Self::Path, _index: u64, _size: u64) -> Option<Self::Path> {
325 /// Builds a `Clone::clone` shim for `self_ty`. Here, `def_id` is `Clone::clone`.
326 fn build_clone_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Body<'tcx> {
327 debug!("build_clone_shim(def_id={:?})", def_id);
329 let param_env = tcx.param_env(def_id);
331 let mut builder = CloneShimBuilder::new(tcx, def_id, self_ty);
332 let is_copy = self_ty.is_copy_modulo_regions(tcx, param_env);
334 let dest = Place::return_place();
335 let src = tcx.mk_place_deref(Place::from(Local::new(1 + 0)));
337 match self_ty.kind() {
338 _ if is_copy => builder.copy_shim(),
339 ty::Closure(_, substs) => {
340 builder.tuple_like_shim(dest, src, substs.as_closure().upvar_tys())
342 ty::Tuple(..) => builder.tuple_like_shim(dest, src, self_ty.tuple_fields()),
343 ty::Generator(gen_def_id, substs, hir::Movability::Movable) => {
344 builder.generator_shim(dest, src, *gen_def_id, substs.as_generator())
346 _ => bug!("clone shim for `{:?}` which is not `Copy` and is not an aggregate", self_ty),
352 struct CloneShimBuilder<'tcx> {
355 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
356 blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
358 sig: ty::FnSig<'tcx>,
361 impl<'tcx> CloneShimBuilder<'tcx> {
362 fn new(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Self {
363 // we must subst the self_ty because it's
364 // otherwise going to be TySelf and we can't index
365 // or access fields of a Place of type TySelf.
366 let sig = tcx.bound_fn_sig(def_id).subst(tcx, &[self_ty.into()]);
367 let sig = tcx.erase_late_bound_regions(sig);
368 let span = tcx.def_span(def_id);
373 local_decls: local_decls_for_sig(&sig, span),
374 blocks: IndexVec::new(),
380 fn into_mir(self) -> Body<'tcx> {
381 let source = MirSource::from_instance(ty::InstanceDef::CloneShim(
383 self.sig.inputs_and_output[0],
385 new_body(source, self.blocks, self.local_decls, self.sig.inputs().len(), self.span)
388 fn source_info(&self) -> SourceInfo {
389 SourceInfo::outermost(self.span)
394 statements: Vec<Statement<'tcx>>,
395 kind: TerminatorKind<'tcx>,
398 let source_info = self.source_info();
399 self.blocks.push(BasicBlockData {
401 terminator: Some(Terminator { source_info, kind }),
406 /// Gives the index of an upcoming BasicBlock, with an offset.
407 /// offset=0 will give you the index of the next BasicBlock,
408 /// offset=1 will give the index of the next-to-next block,
409 /// offset=-1 will give you the index of the last-created block
410 fn block_index_offset(&self, offset: usize) -> BasicBlock {
411 BasicBlock::new(self.blocks.len() + offset)
414 fn make_statement(&self, kind: StatementKind<'tcx>) -> Statement<'tcx> {
415 Statement { source_info: self.source_info(), kind }
418 fn copy_shim(&mut self) {
419 let rcvr = self.tcx.mk_place_deref(Place::from(Local::new(1 + 0)));
420 let ret_statement = self.make_statement(StatementKind::Assign(Box::new((
421 Place::return_place(),
422 Rvalue::Use(Operand::Copy(rcvr)),
424 self.block(vec![ret_statement], TerminatorKind::Return, false);
427 fn make_place(&mut self, mutability: Mutability, ty: Ty<'tcx>) -> Place<'tcx> {
428 let span = self.span;
429 let mut local = LocalDecl::new(ty, span);
430 if mutability == Mutability::Not {
431 local = local.immutable();
433 Place::from(self.local_decls.push(local))
446 // `func == Clone::clone(&ty) -> ty`
447 let func_ty = tcx.mk_fn_def(self.def_id, [ty]);
448 let func = Operand::Constant(Box::new(Constant {
451 literal: ConstantKind::zero_sized(func_ty),
454 let ref_loc = self.make_place(
456 tcx.mk_ref(tcx.lifetimes.re_erased, ty::TypeAndMut { ty, mutbl: hir::Mutability::Not }),
459 // `let ref_loc: &ty = &src;`
460 let statement = self.make_statement(StatementKind::Assign(Box::new((
462 Rvalue::Ref(tcx.lifetimes.re_erased, BorrowKind::Shared, src),
465 // `let loc = Clone::clone(ref_loc);`
468 TerminatorKind::Call {
470 args: vec![Operand::Move(ref_loc)],
473 cleanup: Some(cleanup),
486 mut unwind: BasicBlock,
490 I: IntoIterator<Item = Ty<'tcx>>,
492 // For an iterator of length n, create 2*n + 1 blocks.
493 for (i, ity) in tys.into_iter().enumerate() {
494 // Each iteration creates two blocks, referred to here as block 2*i and block 2*i + 1.
496 // Block 2*i attempts to clone the field. If successful it branches to 2*i + 2 (the
497 // next clone block). If unsuccessful it branches to the previous unwind block, which
498 // is initially the `unwind` argument passed to this function.
500 // Block 2*i + 1 is the unwind block for this iteration. It drops the cloned value
501 // created by block 2*i. We store this block in `unwind` so that the next clone block
502 // will unwind to it if cloning fails.
504 let field = Field::new(i);
505 let src_field = self.tcx.mk_place_field(src, field, ity);
507 let dest_field = self.tcx.mk_place_field(dest, field, ity);
509 let next_unwind = self.block_index_offset(1);
510 let next_block = self.block_index_offset(2);
511 self.make_clone_call(dest_field, src_field, ity, next_block, unwind);
514 TerminatorKind::Drop { place: dest_field, target: unwind, unwind: None },
517 unwind = next_unwind;
519 // If all clones succeed then we end up here.
520 self.block(vec![], TerminatorKind::Goto { target }, false);
524 fn tuple_like_shim<I>(&mut self, dest: Place<'tcx>, src: Place<'tcx>, tys: I)
526 I: IntoIterator<Item = Ty<'tcx>>,
528 self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false);
529 let unwind = self.block(vec![], TerminatorKind::Resume, true);
530 let target = self.block(vec![], TerminatorKind::Return, false);
532 let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, tys);
540 substs: GeneratorSubsts<'tcx>,
542 self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false);
543 let unwind = self.block(vec![], TerminatorKind::Resume, true);
544 // This will get overwritten with a switch once we know the target blocks
545 let switch = self.block(vec![], TerminatorKind::Unreachable, false);
546 let unwind = self.clone_fields(dest, src, switch, unwind, substs.upvar_tys());
547 let target = self.block(vec![], TerminatorKind::Return, false);
548 let unreachable = self.block(vec![], TerminatorKind::Unreachable, false);
549 let mut cases = Vec::with_capacity(substs.state_tys(gen_def_id, self.tcx).count());
550 for (index, state_tys) in substs.state_tys(gen_def_id, self.tcx).enumerate() {
551 let variant_index = VariantIdx::new(index);
552 let dest = self.tcx.mk_place_downcast_unnamed(dest, variant_index);
553 let src = self.tcx.mk_place_downcast_unnamed(src, variant_index);
554 let clone_block = self.block_index_offset(1);
555 let start_block = self.block(
556 vec![self.make_statement(StatementKind::SetDiscriminant {
557 place: Box::new(Place::return_place()),
560 TerminatorKind::Goto { target: clone_block },
563 cases.push((index as u128, start_block));
564 let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, state_tys);
566 let discr_ty = substs.discr_ty(self.tcx);
567 let temp = self.make_place(Mutability::Mut, discr_ty);
568 let rvalue = Rvalue::Discriminant(src);
569 let statement = self.make_statement(StatementKind::Assign(Box::new((temp, rvalue))));
570 match &mut self.blocks[switch] {
571 BasicBlockData { statements, terminator: Some(Terminator { kind, .. }), .. } => {
572 statements.push(statement);
573 *kind = TerminatorKind::SwitchInt {
574 discr: Operand::Move(temp),
575 targets: SwitchTargets::new(cases.into_iter(), unreachable),
578 BasicBlockData { terminator: None, .. } => unreachable!(),
583 /// Builds a "call" shim for `instance`. The shim calls the function specified by `call_kind`,
584 /// first adjusting its first argument according to `rcvr_adjustment`.
585 #[instrument(level = "debug", skip(tcx), ret)]
586 fn build_call_shim<'tcx>(
588 instance: ty::InstanceDef<'tcx>,
589 rcvr_adjustment: Option<Adjustment>,
590 call_kind: CallKind<'tcx>,
592 // `FnPtrShim` contains the fn pointer type that a call shim is being built for - this is used
593 // to substitute into the signature of the shim. It is not necessary for users of this
594 // MIR body to perform further substitutions (see `InstanceDef::has_polymorphic_mir_body`).
595 let (sig_substs, untuple_args) = if let ty::InstanceDef::FnPtrShim(_, ty) = instance {
596 let sig = tcx.erase_late_bound_regions(ty.fn_sig(tcx));
598 let untuple_args = sig.inputs();
600 // Create substitutions for the `Self` and `Args` generic parameters of the shim body.
601 let arg_tup = tcx.mk_tup(untuple_args.iter());
603 (Some([ty.into(), arg_tup.into()]), Some(untuple_args))
608 let def_id = instance.def_id();
609 let sig = tcx.bound_fn_sig(def_id);
610 let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig));
612 assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body());
614 if let Some(sig_substs) = sig_substs { sig.subst(tcx, &sig_substs) } else { sig.0 };
616 if let CallKind::Indirect(fnty) = call_kind {
617 // `sig` determines our local decls, and thus the callee type in the `Call` terminator. This
618 // can only be an `FnDef` or `FnPtr`, but currently will be `Self` since the types come from
619 // the implemented `FnX` trait.
621 // Apply the opposite adjustment to the MIR input.
622 let mut inputs_and_output = sig.inputs_and_output.to_vec();
624 // Initial signature is `fn(&? Self, Args) -> Self::Output` where `Args` is a tuple of the
625 // fn arguments. `Self` may be passed via (im)mutable reference or by-value.
626 assert_eq!(inputs_and_output.len(), 3);
628 // `Self` is always the original fn type `ty`. The MIR call terminator is only defined for
629 // `FnDef` and `FnPtr` callees, not the `Self` type param.
630 let self_arg = &mut inputs_and_output[0];
631 *self_arg = match rcvr_adjustment.unwrap() {
632 Adjustment::Identity => fnty,
633 Adjustment::Deref => tcx.mk_imm_ptr(fnty),
634 Adjustment::RefMut => tcx.mk_mut_ptr(fnty),
636 sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output);
639 // FIXME(eddyb) avoid having this snippet both here and in
640 // `Instance::fn_sig` (introduce `InstanceDef::fn_sig`?).
641 if let ty::InstanceDef::VTableShim(..) = instance {
642 // Modify fn(self, ...) to fn(self: *mut Self, ...)
643 let mut inputs_and_output = sig.inputs_and_output.to_vec();
644 let self_arg = &mut inputs_and_output[0];
645 debug_assert!(tcx.generics_of(def_id).has_self && *self_arg == tcx.types.self_param);
646 *self_arg = tcx.mk_mut_ptr(*self_arg);
647 sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output);
650 let span = tcx.def_span(def_id);
654 let mut local_decls = local_decls_for_sig(&sig, span);
655 let source_info = SourceInfo::outermost(span);
657 let rcvr_place = || {
658 assert!(rcvr_adjustment.is_some());
659 Place::from(Local::new(1 + 0))
661 let mut statements = vec![];
663 let rcvr = rcvr_adjustment.map(|rcvr_adjustment| match rcvr_adjustment {
664 Adjustment::Identity => Operand::Move(rcvr_place()),
665 Adjustment::Deref => Operand::Move(tcx.mk_place_deref(rcvr_place())),
666 Adjustment::RefMut => {
667 // let rcvr = &mut rcvr;
668 let ref_rcvr = local_decls.push(
671 tcx.lifetimes.re_erased,
672 ty::TypeAndMut { ty: sig.inputs()[0], mutbl: hir::Mutability::Mut },
678 let borrow_kind = BorrowKind::Mut { allow_two_phase_borrow: false };
679 statements.push(Statement {
681 kind: StatementKind::Assign(Box::new((
682 Place::from(ref_rcvr),
683 Rvalue::Ref(tcx.lifetimes.re_erased, borrow_kind, rcvr_place()),
686 Operand::Move(Place::from(ref_rcvr))
690 let (callee, mut args) = match call_kind {
691 // `FnPtr` call has no receiver. Args are untupled below.
692 CallKind::Indirect(_) => (rcvr.unwrap(), vec![]),
694 // `FnDef` call with optional receiver.
695 CallKind::Direct(def_id) => {
696 let ty = tcx.type_of(def_id);
698 Operand::Constant(Box::new(Constant {
701 literal: ConstantKind::zero_sized(ty),
703 rcvr.into_iter().collect::<Vec<_>>(),
708 let mut arg_range = 0..sig.inputs().len();
710 // Take the `self` ("receiver") argument out of the range (it's adjusted above).
711 if rcvr_adjustment.is_some() {
712 arg_range.start += 1;
715 // Take the last argument, if we need to untuple it (handled below).
716 if untuple_args.is_some() {
720 // Pass all of the non-special arguments directly.
721 args.extend(arg_range.map(|i| Operand::Move(Place::from(Local::new(1 + i)))));
723 // Untuple the last argument, if we have to.
724 if let Some(untuple_args) = untuple_args {
725 let tuple_arg = Local::new(1 + (sig.inputs().len() - 1));
726 args.extend(untuple_args.iter().enumerate().map(|(i, ity)| {
727 Operand::Move(tcx.mk_place_field(Place::from(tuple_arg), Field::new(i), *ity))
731 let n_blocks = if let Some(Adjustment::RefMut) = rcvr_adjustment { 5 } else { 2 };
732 let mut blocks = IndexVec::with_capacity(n_blocks);
733 let block = |blocks: &mut IndexVec<_, _>, statements, kind, is_cleanup| {
734 blocks.push(BasicBlockData {
736 terminator: Some(Terminator { source_info, kind }),
745 TerminatorKind::Call {
748 destination: Place::return_place(),
749 target: Some(BasicBlock::new(1)),
750 cleanup: if let Some(Adjustment::RefMut) = rcvr_adjustment {
751 Some(BasicBlock::new(3))
761 if let Some(Adjustment::RefMut) = rcvr_adjustment {
762 // BB #1 - drop for Self
766 TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(2), unwind: None },
771 block(&mut blocks, vec![], TerminatorKind::Return, false);
772 if let Some(Adjustment::RefMut) = rcvr_adjustment {
773 // BB #3 - drop if closure panics
777 TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(4), unwind: None },
782 block(&mut blocks, vec![], TerminatorKind::Resume, true);
786 new_body(MirSource::from_instance(instance), blocks, local_decls, sig.inputs().len(), span);
788 if let Abi::RustCall = sig.abi {
789 body.spread_arg = Some(Local::new(sig.inputs().len()));
795 pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> {
796 debug_assert!(tcx.is_constructor(ctor_id));
798 let param_env = tcx.param_env(ctor_id);
800 // Normalize the sig.
801 let sig = tcx.fn_sig(ctor_id).no_bound_vars().expect("LBR in ADT constructor signature");
802 let sig = tcx.normalize_erasing_regions(param_env, sig);
804 let ty::Adt(adt_def, substs) = sig.output().kind() else {
805 bug!("unexpected type for ADT ctor {:?}", sig.output());
808 debug!("build_ctor: ctor_id={:?} sig={:?}", ctor_id, sig);
810 let span = tcx.def_span(ctor_id);
812 let local_decls = local_decls_for_sig(&sig, span);
814 let source_info = SourceInfo::outermost(span);
816 let variant_index = if adt_def.is_enum() {
817 adt_def.variant_index_with_ctor_id(ctor_id)
822 // Generate the following MIR:
824 // (return as Variant).field0 = arg0;
825 // (return as Variant).field1 = arg1;
828 debug!("build_ctor: variant_index={:?}", variant_index);
830 let statements = expand_aggregate(
831 Place::return_place(),
832 adt_def.variant(variant_index).fields.iter().enumerate().map(|(idx, field_def)| {
833 (Operand::Move(Place::from(Local::new(idx + 1))), field_def.ty(tcx, substs))
835 AggregateKind::Adt(adt_def.did(), variant_index, substs, None, None),
841 let start_block = BasicBlockData {
843 terminator: Some(Terminator { source_info, kind: TerminatorKind::Return }),
847 let source = MirSource::item(ctor_id);
850 IndexVec::from_elem_n(start_block, 1),
856 crate::pass_manager::dump_mir_for_phase_change(tcx, &body);