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;
19 abort_unwinding_calls, add_call_guards, add_moves_for_packed_drops, deref_separator,
20 pass_manager as pm, remove_noop_landing_pads, simplify,
22 use rustc_middle::mir::patch::MirPatch;
23 use rustc_mir_dataflow::elaborate_drops::{self, DropElaborator, DropFlagMode, DropStyle};
25 pub fn provide(providers: &mut Providers) {
26 providers.mir_shims = make_shim;
29 fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<'tcx> {
30 debug!("make_shim({:?})", instance);
32 let mut result = match instance {
33 ty::InstanceDef::Item(..) => bug!("item {:?} passed to make_shim", instance),
34 ty::InstanceDef::VTableShim(def_id) => {
35 build_call_shim(tcx, instance, Some(Adjustment::Deref), CallKind::Direct(def_id))
37 ty::InstanceDef::FnPtrShim(def_id, ty) => {
38 let trait_ = tcx.trait_of_item(def_id).unwrap();
39 let adjustment = match tcx.fn_trait_kind_from_def_id(trait_) {
40 Some(ty::ClosureKind::FnOnce) => Adjustment::Identity,
41 Some(ty::ClosureKind::FnMut | ty::ClosureKind::Fn) => Adjustment::Deref,
42 None => bug!("fn pointer {:?} is not an fn", ty),
45 build_call_shim(tcx, instance, Some(adjustment), CallKind::Indirect(ty))
47 // We are generating a call back to our def-id, which the
48 // codegen backend knows to turn to an actual call, be it
49 // a virtual call, or a direct call to a function for which
50 // indirect calls must be codegen'd differently than direct ones
51 // (such as `#[track_caller]`).
52 ty::InstanceDef::ReifyShim(def_id) => {
53 build_call_shim(tcx, instance, None, CallKind::Direct(def_id))
55 ty::InstanceDef::ClosureOnceShim { call_once: _, track_caller: _ } => {
56 let fn_mut = tcx.require_lang_item(LangItem::FnMut, None);
58 .associated_items(fn_mut)
59 .in_definition_order()
60 .find(|it| it.kind == ty::AssocKind::Fn)
64 build_call_shim(tcx, instance, Some(Adjustment::RefMut), CallKind::Direct(call_mut))
67 ty::InstanceDef::DropGlue(def_id, ty) => {
68 // FIXME(#91576): Drop shims for generators aren't subject to the MIR passes at the end
69 // of this function. Is this intentional?
70 if let Some(ty::Generator(gen_def_id, substs, _)) = ty.map(Ty::kind) {
71 let body = tcx.optimized_mir(*gen_def_id).generator_drop().unwrap();
72 let body = EarlyBinder(body.clone()).subst(tcx, substs);
73 debug!("make_shim({:?}) = {:?}", instance, body);
77 build_drop_shim(tcx, def_id, ty)
79 ty::InstanceDef::CloneShim(def_id, ty) => build_clone_shim(tcx, def_id, ty),
80 ty::InstanceDef::Virtual(..) => {
81 bug!("InstanceDef::Virtual ({:?}) is for direct calls only", instance)
83 ty::InstanceDef::Intrinsic(_) => {
84 bug!("creating shims from intrinsics ({:?}) is unsupported", instance)
87 debug!("make_shim({:?}) = untransformed {:?}", instance, result);
93 &add_moves_for_packed_drops::AddMovesForPackedDrops,
94 &deref_separator::Derefer,
95 &remove_noop_landing_pads::RemoveNoopLandingPads,
96 &simplify::SimplifyCfg::new("make_shim"),
97 &add_call_guards::CriticalCallEdges,
98 &abort_unwinding_calls::AbortUnwindingCalls,
100 Some(MirPhase::Runtime(RuntimePhase::Optimized)),
103 debug!("make_shim({:?}) = {:?}", instance, result);
108 #[derive(Copy, Clone, Debug, PartialEq)]
110 /// Pass the receiver as-is.
113 /// We get passed `&[mut] self` and call the target with `*self`.
115 /// This either copies `self` (if `Self: Copy`, eg. for function items), or moves out of it
116 /// (for `VTableShim`, which effectively is passed `&own Self`).
119 /// We get passed `self: Self` and call the target with `&mut self`.
121 /// In this case we need to ensure that the `Self` is dropped after the call, as the callee
122 /// won't do it for us.
126 #[derive(Copy, Clone, Debug, PartialEq)]
127 enum CallKind<'tcx> {
128 /// Call the `FnPtr` that was passed as the receiver.
131 /// Call a known `FnDef`.
135 fn local_decls_for_sig<'tcx>(
136 sig: &ty::FnSig<'tcx>,
138 ) -> IndexVec<Local, LocalDecl<'tcx>> {
139 iter::once(LocalDecl::new(sig.output(), span))
140 .chain(sig.inputs().iter().map(|ity| LocalDecl::new(*ity, span).immutable()))
144 fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) -> Body<'tcx> {
145 debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty);
147 assert!(!matches!(ty, Some(ty) if ty.is_generator()));
149 let substs = if let Some(ty) = ty {
150 tcx.intern_substs(&[ty.into()])
152 InternalSubsts::identity_for_item(tcx, def_id)
154 let sig = tcx.fn_sig(def_id).subst(tcx, substs);
155 let sig = tcx.erase_late_bound_regions(sig);
156 let span = tcx.def_span(def_id);
158 let source_info = SourceInfo::outermost(span);
160 let return_block = BasicBlock::new(1);
161 let mut blocks = IndexVec::with_capacity(2);
162 let block = |blocks: &mut IndexVec<_, _>, kind| {
163 blocks.push(BasicBlockData {
165 terminator: Some(Terminator { source_info, kind }),
169 block(&mut blocks, TerminatorKind::Goto { target: return_block });
170 block(&mut blocks, TerminatorKind::Return);
172 let source = MirSource::from_instance(ty::InstanceDef::DropGlue(def_id, ty));
174 new_body(source, blocks, local_decls_for_sig(&sig, span), sig.inputs().len(), span);
176 // The first argument (index 0), but add 1 for the return value.
177 let mut dropee_ptr = Place::from(Local::new(1 + 0));
178 if tcx.sess.opts.unstable_opts.mir_emit_retag {
179 // We want to treat the function argument as if it was passed by `&mut`. As such, we
183 // Retag(temp, FnEntry)
185 // It's important that we do this first, before anything that depends on `dropee_ptr`
186 // has been put into the body.
187 let reborrow = Rvalue::Ref(
188 tcx.lifetimes.re_erased,
189 BorrowKind::Mut { allow_two_phase_borrow: false },
190 tcx.mk_place_deref(dropee_ptr),
192 let ref_ty = reborrow.ty(body.local_decls(), tcx);
193 dropee_ptr = body.local_decls.push(LocalDecl::new(ref_ty, span)).into();
194 let new_statements = [
195 StatementKind::Assign(Box::new((dropee_ptr, reborrow))),
196 StatementKind::Retag(RetagKind::FnEntry, Box::new(dropee_ptr)),
198 for s in new_statements {
199 body.basic_blocks_mut()[START_BLOCK]
201 .push(Statement { source_info, kind: s });
207 let param_env = tcx.param_env_reveal_all_normalized(def_id);
209 DropShimElaborator { body: &body, patch: MirPatch::new(&body), tcx, param_env };
210 let dropee = tcx.mk_place_deref(dropee_ptr);
211 let resume_block = elaborator.patch.resume_block();
212 elaborate_drops::elaborate_drop(
218 elaborate_drops::Unwind::To(resume_block),
223 patch.apply(&mut body);
230 source: MirSource<'tcx>,
231 basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
232 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
239 IndexVec::from_elem_n(
244 inlined_parent_scope: None,
245 local_data: ClearCrossCrate::Clear,
255 // FIXME(compiler-errors): is this correct?
260 pub struct DropShimElaborator<'a, 'tcx> {
261 pub body: &'a Body<'tcx>,
262 pub patch: MirPatch<'tcx>,
263 pub tcx: TyCtxt<'tcx>,
264 pub param_env: ty::ParamEnv<'tcx>,
267 impl fmt::Debug for DropShimElaborator<'_, '_> {
268 fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
273 impl<'a, 'tcx> DropElaborator<'a, 'tcx> for DropShimElaborator<'a, 'tcx> {
276 fn patch(&mut self) -> &mut MirPatch<'tcx> {
279 fn body(&self) -> &'a Body<'tcx> {
282 fn tcx(&self) -> TyCtxt<'tcx> {
285 fn param_env(&self) -> ty::ParamEnv<'tcx> {
289 fn drop_style(&self, _path: Self::Path, mode: DropFlagMode) -> DropStyle {
291 DropFlagMode::Shallow => {
292 // Drops for the contained fields are "shallow" and "static" - they will simply call
293 // the field's own drop glue.
296 DropFlagMode::Deep => {
297 // The top-level drop is "deep" and "open" - it will be elaborated to a drop ladder
298 // dropping each field contained in the value.
304 fn get_drop_flag(&mut self, _path: Self::Path) -> Option<Operand<'tcx>> {
308 fn clear_drop_flag(&mut self, _location: Location, _path: Self::Path, _mode: DropFlagMode) {}
310 fn field_subpath(&self, _path: Self::Path, _field: Field) -> Option<Self::Path> {
313 fn deref_subpath(&self, _path: Self::Path) -> Option<Self::Path> {
316 fn downcast_subpath(&self, _path: Self::Path, _variant: VariantIdx) -> Option<Self::Path> {
319 fn array_subpath(&self, _path: Self::Path, _index: u64, _size: u64) -> Option<Self::Path> {
324 /// Builds a `Clone::clone` shim for `self_ty`. Here, `def_id` is `Clone::clone`.
325 fn build_clone_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Body<'tcx> {
326 debug!("build_clone_shim(def_id={:?})", def_id);
328 let param_env = tcx.param_env(def_id);
330 let mut builder = CloneShimBuilder::new(tcx, def_id, self_ty);
331 let is_copy = self_ty.is_copy_modulo_regions(tcx, param_env);
333 let dest = Place::return_place();
334 let src = tcx.mk_place_deref(Place::from(Local::new(1 + 0)));
336 match self_ty.kind() {
337 _ if is_copy => builder.copy_shim(),
338 ty::Closure(_, substs) => {
339 builder.tuple_like_shim(dest, src, substs.as_closure().upvar_tys())
341 ty::Tuple(..) => builder.tuple_like_shim(dest, src, self_ty.tuple_fields()),
342 ty::Generator(gen_def_id, substs, hir::Movability::Movable) => {
343 builder.generator_shim(dest, src, *gen_def_id, substs.as_generator())
345 _ => bug!("clone shim for `{:?}` which is not `Copy` and is not an aggregate", self_ty),
351 struct CloneShimBuilder<'tcx> {
354 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
355 blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
357 sig: ty::FnSig<'tcx>,
360 impl<'tcx> CloneShimBuilder<'tcx> {
361 fn new(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Self {
362 // we must subst the self_ty because it's
363 // otherwise going to be TySelf and we can't index
364 // or access fields of a Place of type TySelf.
365 let sig = tcx.fn_sig(def_id).subst(tcx, &[self_ty.into()]);
366 let sig = tcx.erase_late_bound_regions(sig);
367 let span = tcx.def_span(def_id);
372 local_decls: local_decls_for_sig(&sig, span),
373 blocks: IndexVec::new(),
379 fn into_mir(self) -> Body<'tcx> {
380 let source = MirSource::from_instance(ty::InstanceDef::CloneShim(
382 self.sig.inputs_and_output[0],
384 new_body(source, self.blocks, self.local_decls, self.sig.inputs().len(), self.span)
387 fn source_info(&self) -> SourceInfo {
388 SourceInfo::outermost(self.span)
393 statements: Vec<Statement<'tcx>>,
394 kind: TerminatorKind<'tcx>,
397 let source_info = self.source_info();
398 self.blocks.push(BasicBlockData {
400 terminator: Some(Terminator { source_info, kind }),
405 /// Gives the index of an upcoming BasicBlock, with an offset.
406 /// offset=0 will give you the index of the next BasicBlock,
407 /// offset=1 will give the index of the next-to-next block,
408 /// offset=-1 will give you the index of the last-created block
409 fn block_index_offset(&self, offset: usize) -> BasicBlock {
410 BasicBlock::new(self.blocks.len() + offset)
413 fn make_statement(&self, kind: StatementKind<'tcx>) -> Statement<'tcx> {
414 Statement { source_info: self.source_info(), kind }
417 fn copy_shim(&mut self) {
418 let rcvr = self.tcx.mk_place_deref(Place::from(Local::new(1 + 0)));
419 let ret_statement = self.make_statement(StatementKind::Assign(Box::new((
420 Place::return_place(),
421 Rvalue::Use(Operand::Copy(rcvr)),
423 self.block(vec![ret_statement], TerminatorKind::Return, false);
426 fn make_place(&mut self, mutability: Mutability, ty: Ty<'tcx>) -> Place<'tcx> {
427 let span = self.span;
428 let mut local = LocalDecl::new(ty, span);
429 if mutability.is_not() {
430 local = local.immutable();
432 Place::from(self.local_decls.push(local))
445 // `func == Clone::clone(&ty) -> ty`
446 let func_ty = tcx.mk_fn_def(self.def_id, [ty]);
447 let func = Operand::Constant(Box::new(Constant {
450 literal: ConstantKind::zero_sized(func_ty),
453 let ref_loc = self.make_place(
455 tcx.mk_ref(tcx.lifetimes.re_erased, ty::TypeAndMut { ty, mutbl: hir::Mutability::Not }),
458 // `let ref_loc: &ty = &src;`
459 let statement = self.make_statement(StatementKind::Assign(Box::new((
461 Rvalue::Ref(tcx.lifetimes.re_erased, BorrowKind::Shared, src),
464 // `let loc = Clone::clone(ref_loc);`
467 TerminatorKind::Call {
469 args: vec![Operand::Move(ref_loc)],
472 cleanup: Some(cleanup),
485 mut unwind: BasicBlock,
489 I: IntoIterator<Item = Ty<'tcx>>,
491 // For an iterator of length n, create 2*n + 1 blocks.
492 for (i, ity) in tys.into_iter().enumerate() {
493 // Each iteration creates two blocks, referred to here as block 2*i and block 2*i + 1.
495 // Block 2*i attempts to clone the field. If successful it branches to 2*i + 2 (the
496 // next clone block). If unsuccessful it branches to the previous unwind block, which
497 // is initially the `unwind` argument passed to this function.
499 // Block 2*i + 1 is the unwind block for this iteration. It drops the cloned value
500 // created by block 2*i. We store this block in `unwind` so that the next clone block
501 // will unwind to it if cloning fails.
503 let field = Field::new(i);
504 let src_field = self.tcx.mk_place_field(src, field, ity);
506 let dest_field = self.tcx.mk_place_field(dest, field, ity);
508 let next_unwind = self.block_index_offset(1);
509 let next_block = self.block_index_offset(2);
510 self.make_clone_call(dest_field, src_field, ity, next_block, unwind);
513 TerminatorKind::Drop { place: dest_field, target: unwind, unwind: None },
516 unwind = next_unwind;
518 // If all clones succeed then we end up here.
519 self.block(vec![], TerminatorKind::Goto { target }, false);
523 fn tuple_like_shim<I>(&mut self, dest: Place<'tcx>, src: Place<'tcx>, tys: I)
525 I: IntoIterator<Item = Ty<'tcx>>,
527 self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false);
528 let unwind = self.block(vec![], TerminatorKind::Resume, true);
529 let target = self.block(vec![], TerminatorKind::Return, false);
531 let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, tys);
539 substs: GeneratorSubsts<'tcx>,
541 self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false);
542 let unwind = self.block(vec![], TerminatorKind::Resume, true);
543 // This will get overwritten with a switch once we know the target blocks
544 let switch = self.block(vec![], TerminatorKind::Unreachable, false);
545 let unwind = self.clone_fields(dest, src, switch, unwind, substs.upvar_tys());
546 let target = self.block(vec![], TerminatorKind::Return, false);
547 let unreachable = self.block(vec![], TerminatorKind::Unreachable, false);
548 let mut cases = Vec::with_capacity(substs.state_tys(gen_def_id, self.tcx).count());
549 for (index, state_tys) in substs.state_tys(gen_def_id, self.tcx).enumerate() {
550 let variant_index = VariantIdx::new(index);
551 let dest = self.tcx.mk_place_downcast_unnamed(dest, variant_index);
552 let src = self.tcx.mk_place_downcast_unnamed(src, variant_index);
553 let clone_block = self.block_index_offset(1);
554 let start_block = self.block(
555 vec![self.make_statement(StatementKind::SetDiscriminant {
556 place: Box::new(Place::return_place()),
559 TerminatorKind::Goto { target: clone_block },
562 cases.push((index as u128, start_block));
563 let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, state_tys);
565 let discr_ty = substs.discr_ty(self.tcx);
566 let temp = self.make_place(Mutability::Mut, discr_ty);
567 let rvalue = Rvalue::Discriminant(src);
568 let statement = self.make_statement(StatementKind::Assign(Box::new((temp, rvalue))));
569 match &mut self.blocks[switch] {
570 BasicBlockData { statements, terminator: Some(Terminator { kind, .. }), .. } => {
571 statements.push(statement);
572 *kind = TerminatorKind::SwitchInt {
573 discr: Operand::Move(temp),
574 targets: SwitchTargets::new(cases.into_iter(), unreachable),
577 BasicBlockData { terminator: None, .. } => unreachable!(),
582 /// Builds a "call" shim for `instance`. The shim calls the function specified by `call_kind`,
583 /// first adjusting its first argument according to `rcvr_adjustment`.
584 #[instrument(level = "debug", skip(tcx), ret)]
585 fn build_call_shim<'tcx>(
587 instance: ty::InstanceDef<'tcx>,
588 rcvr_adjustment: Option<Adjustment>,
589 call_kind: CallKind<'tcx>,
591 // `FnPtrShim` contains the fn pointer type that a call shim is being built for - this is used
592 // to substitute into the signature of the shim. It is not necessary for users of this
593 // MIR body to perform further substitutions (see `InstanceDef::has_polymorphic_mir_body`).
594 let (sig_substs, untuple_args) = if let ty::InstanceDef::FnPtrShim(_, ty) = instance {
595 let sig = tcx.erase_late_bound_regions(ty.fn_sig(tcx));
597 let untuple_args = sig.inputs();
599 // Create substitutions for the `Self` and `Args` generic parameters of the shim body.
600 let arg_tup = tcx.mk_tup(untuple_args.iter());
602 (Some([ty.into(), arg_tup.into()]), Some(untuple_args))
607 let def_id = instance.def_id();
608 let sig = tcx.fn_sig(def_id);
609 let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig));
611 assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body());
613 if let Some(sig_substs) = sig_substs { sig.subst(tcx, &sig_substs) } else { sig.0 };
615 if let CallKind::Indirect(fnty) = call_kind {
616 // `sig` determines our local decls, and thus the callee type in the `Call` terminator. This
617 // can only be an `FnDef` or `FnPtr`, but currently will be `Self` since the types come from
618 // the implemented `FnX` trait.
620 // Apply the opposite adjustment to the MIR input.
621 let mut inputs_and_output = sig.inputs_and_output.to_vec();
623 // Initial signature is `fn(&? Self, Args) -> Self::Output` where `Args` is a tuple of the
624 // fn arguments. `Self` may be passed via (im)mutable reference or by-value.
625 assert_eq!(inputs_and_output.len(), 3);
627 // `Self` is always the original fn type `ty`. The MIR call terminator is only defined for
628 // `FnDef` and `FnPtr` callees, not the `Self` type param.
629 let self_arg = &mut inputs_and_output[0];
630 *self_arg = match rcvr_adjustment.unwrap() {
631 Adjustment::Identity => fnty,
632 Adjustment::Deref => tcx.mk_imm_ptr(fnty),
633 Adjustment::RefMut => tcx.mk_mut_ptr(fnty),
635 sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output);
638 // FIXME(eddyb) avoid having this snippet both here and in
639 // `Instance::fn_sig` (introduce `InstanceDef::fn_sig`?).
640 if let ty::InstanceDef::VTableShim(..) = instance {
641 // Modify fn(self, ...) to fn(self: *mut Self, ...)
642 let mut inputs_and_output = sig.inputs_and_output.to_vec();
643 let self_arg = &mut inputs_and_output[0];
644 debug_assert!(tcx.generics_of(def_id).has_self && *self_arg == tcx.types.self_param);
645 *self_arg = tcx.mk_mut_ptr(*self_arg);
646 sig.inputs_and_output = tcx.intern_type_list(&inputs_and_output);
649 let span = tcx.def_span(def_id);
653 let mut local_decls = local_decls_for_sig(&sig, span);
654 let source_info = SourceInfo::outermost(span);
656 let rcvr_place = || {
657 assert!(rcvr_adjustment.is_some());
658 Place::from(Local::new(1 + 0))
660 let mut statements = vec![];
662 let rcvr = rcvr_adjustment.map(|rcvr_adjustment| match rcvr_adjustment {
663 Adjustment::Identity => Operand::Move(rcvr_place()),
664 Adjustment::Deref => Operand::Move(tcx.mk_place_deref(rcvr_place())),
665 Adjustment::RefMut => {
666 // let rcvr = &mut rcvr;
667 let ref_rcvr = local_decls.push(
670 tcx.lifetimes.re_erased,
671 ty::TypeAndMut { ty: sig.inputs()[0], mutbl: hir::Mutability::Mut },
677 let borrow_kind = BorrowKind::Mut { allow_two_phase_borrow: false };
678 statements.push(Statement {
680 kind: StatementKind::Assign(Box::new((
681 Place::from(ref_rcvr),
682 Rvalue::Ref(tcx.lifetimes.re_erased, borrow_kind, rcvr_place()),
685 Operand::Move(Place::from(ref_rcvr))
689 let (callee, mut args) = match call_kind {
690 // `FnPtr` call has no receiver. Args are untupled below.
691 CallKind::Indirect(_) => (rcvr.unwrap(), vec![]),
693 // `FnDef` call with optional receiver.
694 CallKind::Direct(def_id) => {
695 let ty = tcx.type_of(def_id);
697 Operand::Constant(Box::new(Constant {
700 literal: ConstantKind::zero_sized(ty),
702 rcvr.into_iter().collect::<Vec<_>>(),
707 let mut arg_range = 0..sig.inputs().len();
709 // Take the `self` ("receiver") argument out of the range (it's adjusted above).
710 if rcvr_adjustment.is_some() {
711 arg_range.start += 1;
714 // Take the last argument, if we need to untuple it (handled below).
715 if untuple_args.is_some() {
719 // Pass all of the non-special arguments directly.
720 args.extend(arg_range.map(|i| Operand::Move(Place::from(Local::new(1 + i)))));
722 // Untuple the last argument, if we have to.
723 if let Some(untuple_args) = untuple_args {
724 let tuple_arg = Local::new(1 + (sig.inputs().len() - 1));
725 args.extend(untuple_args.iter().enumerate().map(|(i, ity)| {
726 Operand::Move(tcx.mk_place_field(Place::from(tuple_arg), Field::new(i), *ity))
730 let n_blocks = if let Some(Adjustment::RefMut) = rcvr_adjustment { 5 } else { 2 };
731 let mut blocks = IndexVec::with_capacity(n_blocks);
732 let block = |blocks: &mut IndexVec<_, _>, statements, kind, is_cleanup| {
733 blocks.push(BasicBlockData {
735 terminator: Some(Terminator { source_info, kind }),
744 TerminatorKind::Call {
747 destination: Place::return_place(),
748 target: Some(BasicBlock::new(1)),
749 cleanup: if let Some(Adjustment::RefMut) = rcvr_adjustment {
750 Some(BasicBlock::new(3))
760 if let Some(Adjustment::RefMut) = rcvr_adjustment {
761 // BB #1 - drop for Self
765 TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(2), unwind: None },
770 block(&mut blocks, vec![], TerminatorKind::Return, false);
771 if let Some(Adjustment::RefMut) = rcvr_adjustment {
772 // BB #3 - drop if closure panics
776 TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(4), unwind: None },
781 block(&mut blocks, vec![], TerminatorKind::Resume, true);
785 new_body(MirSource::from_instance(instance), blocks, local_decls, sig.inputs().len(), span);
787 if let Abi::RustCall = sig.abi {
788 body.spread_arg = Some(Local::new(sig.inputs().len()));
794 pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> {
795 debug_assert!(tcx.is_constructor(ctor_id));
797 let param_env = tcx.param_env(ctor_id);
799 // Normalize the sig.
804 .expect("LBR in ADT constructor signature");
805 let sig = tcx.normalize_erasing_regions(param_env, sig);
807 let ty::Adt(adt_def, substs) = sig.output().kind() else {
808 bug!("unexpected type for ADT ctor {:?}", sig.output());
811 debug!("build_ctor: ctor_id={:?} sig={:?}", ctor_id, sig);
813 let span = tcx.def_span(ctor_id);
815 let local_decls = local_decls_for_sig(&sig, span);
817 let source_info = SourceInfo::outermost(span);
819 let variant_index = if adt_def.is_enum() {
820 adt_def.variant_index_with_ctor_id(ctor_id)
825 // Generate the following MIR:
827 // (return as Variant).field0 = arg0;
828 // (return as Variant).field1 = arg1;
831 debug!("build_ctor: variant_index={:?}", variant_index);
833 let kind = AggregateKind::Adt(adt_def.did(), variant_index, substs, None, None);
834 let variant = adt_def.variant(variant_index);
835 let statement = Statement {
836 kind: StatementKind::Assign(Box::new((
837 Place::return_place(),
840 (0..variant.fields.len())
841 .map(|idx| Operand::Move(Place::from(Local::new(idx + 1))))
848 let start_block = BasicBlockData {
849 statements: vec![statement],
850 terminator: Some(Terminator { source_info, kind: TerminatorKind::Return }),
854 let source = MirSource::item(ctor_id);
857 IndexVec::from_elem_n(start_block, 1),
863 crate::pass_manager::dump_mir_for_phase_change(tcx, &body);