1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 use rustc::hir::def_id::DefId;
15 use rustc::ty::{self, Ty, TyCtxt, GenericParamDefKind};
16 use rustc::ty::layout::VariantIdx;
17 use rustc::ty::subst::{Subst, Substs};
18 use rustc::ty::query::Providers;
20 use rustc_data_structures::indexed_vec::{IndexVec, Idx};
22 use rustc_target::spec::abi::Abi;
29 use transform::{add_moves_for_packed_drops, add_call_guards};
30 use transform::{remove_noop_landing_pads, no_landing_pads, simplify};
31 use util::elaborate_drops::{self, DropElaborator, DropStyle, DropFlagMode};
32 use util::patch::MirPatch;
34 pub fn provide(providers: &mut Providers) {
35 providers.mir_shims = make_shim;
38 fn make_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
39 instance: ty::InstanceDef<'tcx>)
42 debug!("make_shim({:?})", instance);
44 let mut result = match instance {
45 ty::InstanceDef::Item(..) =>
46 bug!("item {:?} passed to make_shim", instance),
47 ty::InstanceDef::VtableShim(def_id) => {
51 Adjustment::DerefMove,
52 CallKind::Direct(def_id),
56 ty::InstanceDef::FnPtrShim(def_id, ty) => {
57 let trait_ = tcx.trait_of_item(def_id).unwrap();
58 let adjustment = match tcx.lang_items().fn_trait_kind(trait_) {
59 Some(ty::ClosureKind::FnOnce) => Adjustment::Identity,
60 Some(ty::ClosureKind::FnMut) |
61 Some(ty::ClosureKind::Fn) => Adjustment::Deref,
62 None => bug!("fn pointer {:?} is not an fn", ty)
64 // HACK: we need the "real" argument types for the MIR,
65 // but because our substs are (Self, Args), where Args
66 // is a tuple, we must include the *concrete* argument
67 // types in the MIR. They will be substituted again with
68 // the param-substs, but because they are concrete, this
69 // will not do any harm.
70 let sig = tcx.erase_late_bound_regions(&ty.fn_sig(tcx));
71 let arg_tys = sig.inputs();
81 ty::InstanceDef::Virtual(def_id, _) => {
82 // We are generating a call back to our def-id, which the
83 // codegen backend knows to turn to an actual virtual call.
88 CallKind::Direct(def_id),
92 ty::InstanceDef::ClosureOnceShim { call_once } => {
93 let fn_mut = tcx.lang_items().fn_mut_trait().unwrap();
94 let call_mut = tcx.global_tcx()
95 .associated_items(fn_mut)
96 .find(|it| it.kind == ty::AssociatedKind::Method)
103 CallKind::Direct(call_mut),
107 ty::InstanceDef::DropGlue(def_id, ty) => {
108 build_drop_shim(tcx, def_id, ty)
110 ty::InstanceDef::CloneShim(def_id, ty) => {
111 let name = tcx.item_name(def_id);
113 build_clone_shim(tcx, def_id, ty)
114 } else if name == "clone_from" {
115 debug!("make_shim({:?}: using default trait implementation", instance);
116 return tcx.optimized_mir(def_id);
118 bug!("builtin clone shim {:?} not supported", instance)
121 ty::InstanceDef::Intrinsic(_) => {
122 bug!("creating shims from intrinsics ({:?}) is unsupported", instance)
125 debug!("make_shim({:?}) = untransformed {:?}", instance, result);
126 add_moves_for_packed_drops::add_moves_for_packed_drops(
127 tcx, &mut result, instance.def_id());
128 no_landing_pads::no_landing_pads(tcx, &mut result);
129 remove_noop_landing_pads::remove_noop_landing_pads(tcx, &mut result);
130 simplify::simplify_cfg(&mut result);
131 add_call_guards::CriticalCallEdges.add_call_guards(&mut result);
132 debug!("make_shim({:?}) = {:?}", instance, result);
134 tcx.alloc_mir(result)
137 #[derive(Copy, Clone, Debug, PartialEq)]
145 #[derive(Copy, Clone, Debug, PartialEq)]
151 fn temp_decl(mutability: Mutability, ty: Ty, span: Span) -> LocalDecl {
152 let source_info = SourceInfo { scope: OUTERMOST_SOURCE_SCOPE, span };
156 user_ty: UserTypeProjections::none(),
159 visibility_scope: source_info.scope,
161 is_user_variable: None,
166 fn local_decls_for_sig<'tcx>(sig: &ty::FnSig<'tcx>, span: Span)
167 -> IndexVec<Local, LocalDecl<'tcx>>
169 iter::once(temp_decl(Mutability::Mut, sig.output(), span))
170 .chain(sig.inputs().iter().map(
171 |ity| temp_decl(Mutability::Not, ity, span)))
175 fn build_drop_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
177 ty: Option<Ty<'tcx>>)
180 debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty);
182 // Check if this is a generator, if so, return the drop glue for it
183 if let Some(&ty::TyS { sty: ty::Generator(gen_def_id, substs, _), .. }) = ty {
184 let mir = &**tcx.optimized_mir(gen_def_id).generator_drop.as_ref().unwrap();
185 return mir.subst(tcx, substs.substs);
188 let substs = if let Some(ty) = ty {
189 tcx.intern_substs(&[ty.into()])
191 Substs::identity_for_item(tcx, def_id)
193 let sig = tcx.fn_sig(def_id).subst(tcx, substs);
194 let sig = tcx.erase_late_bound_regions(&sig);
195 let span = tcx.def_span(def_id);
197 let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE };
199 let return_block = BasicBlock::new(1);
200 let mut blocks = IndexVec::with_capacity(2);
201 let block = |blocks: &mut IndexVec<_, _>, kind| {
202 blocks.push(BasicBlockData {
204 terminator: Some(Terminator { source_info, kind }),
208 block(&mut blocks, TerminatorKind::Goto { target: return_block });
209 block(&mut blocks, TerminatorKind::Return);
211 let mut mir = Mir::new(
213 IndexVec::from_elem_n(
214 SourceScopeData { span: span, parent_scope: None }, 1
216 ClearCrossCrate::Clear,
219 local_decls_for_sig(&sig, span),
226 if let Some(..) = ty {
227 // The first argument (index 0), but add 1 for the return value.
228 let dropee_ptr = Place::Local(Local::new(1+0));
229 if tcx.sess.opts.debugging_opts.mir_emit_retag {
230 // Function arguments should be retagged, and we make this one raw.
231 mir.basic_blocks_mut()[START_BLOCK].statements.insert(0, Statement {
233 kind: StatementKind::Retag(RetagKind::Raw, dropee_ptr.clone()),
237 let param_env = tcx.param_env(def_id).with_reveal_all();
238 let mut elaborator = DropShimElaborator {
240 patch: MirPatch::new(&mir),
244 let dropee = dropee_ptr.deref();
245 let resume_block = elaborator.patch.resume_block();
246 elaborate_drops::elaborate_drop(
252 elaborate_drops::Unwind::To(resume_block),
257 patch.apply(&mut mir);
263 pub struct DropShimElaborator<'a, 'tcx: 'a> {
264 pub mir: &'a Mir<'tcx>,
265 pub patch: MirPatch<'tcx>,
266 pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
267 pub param_env: ty::ParamEnv<'tcx>,
270 impl<'a, 'tcx> fmt::Debug for DropShimElaborator<'a, 'tcx> {
271 fn fmt(&self, _f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
276 impl<'a, 'tcx> DropElaborator<'a, 'tcx> for DropShimElaborator<'a, 'tcx> {
279 fn patch(&mut self) -> &mut MirPatch<'tcx> { &mut self.patch }
280 fn mir(&self) -> &'a Mir<'tcx> { self.mir }
281 fn tcx(&self) -> TyCtxt<'a, 'tcx, 'tcx> { self.tcx }
282 fn param_env(&self) -> ty::ParamEnv<'tcx> { self.param_env }
284 fn drop_style(&self, _path: Self::Path, mode: DropFlagMode) -> DropStyle {
285 if let DropFlagMode::Shallow = mode {
292 fn get_drop_flag(&mut self, _path: Self::Path) -> Option<Operand<'tcx>> {
296 fn clear_drop_flag(&mut self, _location: Location, _path: Self::Path, _mode: DropFlagMode) {
299 fn field_subpath(&self, _path: Self::Path, _field: Field) -> Option<Self::Path> {
302 fn deref_subpath(&self, _path: Self::Path) -> Option<Self::Path> {
305 fn downcast_subpath(&self, _path: Self::Path, _variant: VariantIdx) -> Option<Self::Path> {
308 fn array_subpath(&self, _path: Self::Path, _index: u32, _size: u32) -> Option<Self::Path> {
313 /// Build a `Clone::clone` shim for `self_ty`. Here, `def_id` is `Clone::clone`.
314 fn build_clone_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
319 debug!("build_clone_shim(def_id={:?})", def_id);
321 let mut builder = CloneShimBuilder::new(tcx, def_id, self_ty);
322 let is_copy = !self_ty.moves_by_default(tcx, tcx.param_env(def_id), builder.span);
324 let dest = Place::Local(RETURN_PLACE);
325 let src = Place::Local(Local::new(1+0)).deref();
328 _ if is_copy => builder.copy_shim(),
329 ty::Array(ty, len) => {
330 let len = len.unwrap_usize(tcx);
331 builder.array_shim(dest, src, ty, len)
333 ty::Closure(def_id, substs) => {
334 builder.tuple_like_shim(
336 substs.upvar_tys(def_id, tcx)
339 ty::Tuple(tys) => builder.tuple_like_shim(dest, src, tys.iter().cloned()),
341 bug!("clone shim for `{:?}` which is not `Copy` and is not an aggregate", self_ty)
348 struct CloneShimBuilder<'a, 'tcx: 'a> {
349 tcx: TyCtxt<'a, 'tcx, 'tcx>,
351 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
352 blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
354 sig: ty::FnSig<'tcx>,
357 impl<'a, 'tcx> CloneShimBuilder<'a, 'tcx> {
358 fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>,
360 self_ty: Ty<'tcx>) -> Self {
361 // we must subst the self_ty because it's
362 // otherwise going to be TySelf and we can't index
363 // or access fields of a Place of type TySelf.
364 let substs = tcx.mk_substs_trait(self_ty, &[]);
365 let sig = tcx.fn_sig(def_id).subst(tcx, substs);
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) -> Mir<'tcx> {
382 IndexVec::from_elem_n(
383 SourceScopeData { span: self.span, parent_scope: None }, 1
385 ClearCrossCrate::Clear,
389 self.sig.inputs().len(),
396 fn source_info(&self) -> SourceInfo {
397 SourceInfo { span: self.span, scope: OUTERMOST_SOURCE_SCOPE }
402 statements: Vec<Statement<'tcx>>,
403 kind: TerminatorKind<'tcx>,
406 let source_info = self.source_info();
407 self.blocks.push(BasicBlockData {
409 terminator: Some(Terminator { source_info, kind }),
414 /// Gives the index of an upcoming BasicBlock, with an offset.
415 /// offset=0 will give you the index of the next BasicBlock,
416 /// offset=1 will give the index of the next-to-next block,
417 /// offset=-1 will give you the index of the last-created block
418 fn block_index_offset(&mut self, offset: usize) -> BasicBlock {
419 BasicBlock::new(self.blocks.len() + offset)
422 fn make_statement(&self, kind: StatementKind<'tcx>) -> Statement<'tcx> {
424 source_info: self.source_info(),
429 fn copy_shim(&mut self) {
430 let rcvr = Place::Local(Local::new(1+0)).deref();
431 let ret_statement = self.make_statement(
432 StatementKind::Assign(
433 Place::Local(RETURN_PLACE),
434 box Rvalue::Use(Operand::Copy(rcvr))
437 self.block(vec![ret_statement], TerminatorKind::Return, false);
440 fn make_place(&mut self, mutability: Mutability, ty: Ty<'tcx>) -> Place<'tcx> {
441 let span = self.span;
443 self.local_decls.push(temp_decl(mutability, ty, span))
457 let substs = Substs::for_item(tcx, self.def_id, |param, _| {
459 GenericParamDefKind::Lifetime => tcx.types.re_erased.into(),
460 GenericParamDefKind::Type {..} => ty.into(),
464 // `func == Clone::clone(&ty) -> ty`
465 let func_ty = tcx.mk_fn_def(self.def_id, substs);
466 let func = Operand::Constant(box Constant {
470 literal: ty::Const::zero_sized(self.tcx, func_ty),
473 let ref_loc = self.make_place(
475 tcx.mk_ref(tcx.types.re_erased, ty::TypeAndMut {
477 mutbl: hir::Mutability::MutImmutable,
481 // `let ref_loc: &ty = &src;`
482 let statement = self.make_statement(
483 StatementKind::Assign(
485 box Rvalue::Ref(tcx.types.re_erased, BorrowKind::Shared, src)
489 // `let loc = Clone::clone(ref_loc);`
490 self.block(vec![statement], TerminatorKind::Call {
492 args: vec![Operand::Move(ref_loc)],
493 destination: Some((dest, next)),
494 cleanup: Some(cleanup),
503 loop_body: BasicBlock,
504 loop_end: BasicBlock,
509 let cond = self.make_place(Mutability::Mut, tcx.types.bool);
510 let compute_cond = self.make_statement(
511 StatementKind::Assign(
513 box Rvalue::BinaryOp(BinOp::Ne, Operand::Copy(end), Operand::Copy(beg))
517 // `if end != beg { goto loop_body; } else { goto loop_end; }`
520 TerminatorKind::if_(tcx, Operand::Move(cond), loop_body, loop_end),
525 fn make_usize(&self, value: u64) -> Box<Constant<'tcx>> {
528 ty: self.tcx.types.usize,
530 literal: ty::Const::from_usize(self.tcx, value),
534 fn array_shim(&mut self, dest: Place<'tcx>, src: Place<'tcx>, ty: Ty<'tcx>, len: u64) {
536 let span = self.span;
538 let beg = self.local_decls.push(temp_decl(Mutability::Mut, tcx.types.usize, span));
539 let end = self.make_place(Mutability::Not, tcx.types.usize);
542 // `let mut beg = 0;`
547 StatementKind::Assign(
549 box Rvalue::Use(Operand::Constant(self.make_usize(0)))
553 StatementKind::Assign(
555 box Rvalue::Use(Operand::Constant(self.make_usize(len)))
559 self.block(inits, TerminatorKind::Goto { target: BasicBlock::new(1) }, false);
566 self.loop_header(Place::Local(beg), end, BasicBlock::new(2), BasicBlock::new(4), false);
569 // `dest[i] = Clone::clone(src[beg])`;
570 // Goto #3 if ok, #5 if unwinding happens.
571 let dest_field = dest.clone().index(beg);
572 let src_field = src.index(beg);
573 self.make_clone_call(dest_field, src_field, ty, BasicBlock::new(3),
579 let statements = vec![
581 StatementKind::Assign(
583 box Rvalue::BinaryOp(
585 Operand::Copy(Place::Local(beg)),
586 Operand::Constant(self.make_usize(1))
591 self.block(statements, TerminatorKind::Goto { target: BasicBlock::new(1) }, false);
595 self.block(vec![], TerminatorKind::Return, false);
599 // `let mut beg = 0;`
602 let beg = self.local_decls.push(temp_decl(Mutability::Mut, tcx.types.usize, span));
603 let init = self.make_statement(
604 StatementKind::Assign(
606 box Rvalue::Use(Operand::Constant(self.make_usize(0)))
609 self.block(vec![init], TerminatorKind::Goto { target: BasicBlock::new(6) }, true);
611 // BB #6 (cleanup): loop {
616 self.loop_header(Place::Local(beg), Place::Local(end),
617 BasicBlock::new(7), BasicBlock::new(9), true);
620 // `drop(dest[beg])`;
621 self.block(vec![], TerminatorKind::Drop {
622 location: dest.index(beg),
623 target: BasicBlock::new(8),
630 let statement = self.make_statement(
631 StatementKind::Assign(
633 box Rvalue::BinaryOp(
635 Operand::Copy(Place::Local(beg)),
636 Operand::Constant(self.make_usize(1))
640 self.block(vec![statement], TerminatorKind::Goto { target: BasicBlock::new(6) }, true);
643 self.block(vec![], TerminatorKind::Resume, true);
646 fn tuple_like_shim<I>(&mut self, dest: Place<'tcx>,
647 src: Place<'tcx>, tys: I)
648 where I: Iterator<Item = ty::Ty<'tcx>> {
649 let mut previous_field = None;
650 for (i, ity) in tys.enumerate() {
651 let field = Field::new(i);
652 let src_field = src.clone().field(field, ity);
654 let dest_field = dest.clone().field(field, ity);
656 // #(2i + 1) is the cleanup block for the previous clone operation
657 let cleanup_block = self.block_index_offset(1);
658 // #(2i + 2) is the next cloning block
659 // (or the Return terminator if this is the last block)
660 let next_block = self.block_index_offset(2);
663 // `dest.i = Clone::clone(&src.i);`
664 // Goto #(2i + 2) if ok, #(2i + 1) if unwinding happens.
665 self.make_clone_call(
673 // BB #(2i + 1) (cleanup)
674 if let Some((previous_field, previous_cleanup)) = previous_field.take() {
675 // Drop previous field and goto previous cleanup block.
676 self.block(vec![], TerminatorKind::Drop {
677 location: previous_field,
678 target: previous_cleanup,
682 // Nothing to drop, just resume.
683 self.block(vec![], TerminatorKind::Resume, true);
686 previous_field = Some((dest_field, cleanup_block));
689 self.block(vec![], TerminatorKind::Return, false);
693 /// Build a "call" shim for `def_id`. The shim calls the
694 /// function specified by `call_kind`, first adjusting its first
695 /// argument according to `rcvr_adjustment`.
697 /// If `untuple_args` is a vec of types, the second argument of the
698 /// function will be untupled as these types.
699 fn build_call_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
701 rcvr_adjustment: Adjustment,
703 untuple_args: Option<&[Ty<'tcx>]>)
706 debug!("build_call_shim(def_id={:?}, rcvr_adjustment={:?}, \
707 call_kind={:?}, untuple_args={:?})",
708 def_id, rcvr_adjustment, call_kind, untuple_args);
710 let sig = tcx.fn_sig(def_id);
711 let sig = tcx.erase_late_bound_regions(&sig);
712 let span = tcx.def_span(def_id);
714 debug!("build_call_shim: sig={:?}", sig);
716 let mut local_decls = local_decls_for_sig(&sig, span);
717 let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE };
719 let rcvr_arg = Local::new(1+0);
720 let rcvr_l = Place::Local(rcvr_arg);
721 let mut statements = vec![];
723 let rcvr = match rcvr_adjustment {
724 Adjustment::Identity => Operand::Move(rcvr_l),
725 Adjustment::Deref => Operand::Copy(rcvr_l.deref()),
726 Adjustment::DerefMove => {
727 // fn(Self, ...) -> fn(*mut Self, ...)
728 let arg_ty = local_decls[rcvr_arg].ty;
729 assert!(arg_ty.is_self());
730 local_decls[rcvr_arg].ty = tcx.mk_mut_ptr(arg_ty);
732 Operand::Move(rcvr_l.deref())
734 Adjustment::RefMut => {
735 // let rcvr = &mut rcvr;
736 let ref_rcvr = local_decls.push(temp_decl(
738 tcx.mk_ref(tcx.types.re_erased, ty::TypeAndMut {
740 mutbl: hir::Mutability::MutMutable
744 let borrow_kind = BorrowKind::Mut {
745 allow_two_phase_borrow: false,
747 statements.push(Statement {
749 kind: StatementKind::Assign(
750 Place::Local(ref_rcvr),
751 box Rvalue::Ref(tcx.types.re_erased, borrow_kind, rcvr_l)
754 Operand::Move(Place::Local(ref_rcvr))
758 let (callee, mut args) = match call_kind {
759 CallKind::Indirect => (rcvr, vec![]),
760 CallKind::Direct(def_id) => {
761 let ty = tcx.type_of(def_id);
762 (Operand::Constant(box Constant {
766 literal: ty::Const::zero_sized(tcx, ty),
772 if let Some(untuple_args) = untuple_args {
773 args.extend(untuple_args.iter().enumerate().map(|(i, ity)| {
774 let arg_place = Place::Local(Local::new(1+1));
775 Operand::Move(arg_place.field(Field::new(i), *ity))
778 args.extend((1..sig.inputs().len()).map(|i| {
779 Operand::Move(Place::Local(Local::new(1+i)))
783 let n_blocks = if let Adjustment::RefMut = rcvr_adjustment { 5 } else { 2 };
784 let mut blocks = IndexVec::with_capacity(n_blocks);
785 let block = |blocks: &mut IndexVec<_, _>, statements, kind, is_cleanup| {
786 blocks.push(BasicBlockData {
788 terminator: Some(Terminator { source_info, kind }),
794 block(&mut blocks, statements, TerminatorKind::Call {
797 destination: Some((Place::Local(RETURN_PLACE),
798 BasicBlock::new(1))),
799 cleanup: if let Adjustment::RefMut = rcvr_adjustment {
800 Some(BasicBlock::new(3))
807 if let Adjustment::RefMut = rcvr_adjustment {
808 // BB #1 - drop for Self
809 block(&mut blocks, vec![], TerminatorKind::Drop {
810 location: Place::Local(rcvr_arg),
811 target: BasicBlock::new(2),
816 block(&mut blocks, vec![], TerminatorKind::Return, false);
817 if let Adjustment::RefMut = rcvr_adjustment {
818 // BB #3 - drop if closure panics
819 block(&mut blocks, vec![], TerminatorKind::Drop {
820 location: Place::Local(rcvr_arg),
821 target: BasicBlock::new(4),
826 block(&mut blocks, vec![], TerminatorKind::Resume, true);
829 let mut mir = Mir::new(
831 IndexVec::from_elem_n(
832 SourceScopeData { span: span, parent_scope: None }, 1
834 ClearCrossCrate::Clear,
843 if let Abi::RustCall = sig.abi {
844 mir.spread_arg = Some(Local::new(sig.inputs().len()));
849 pub fn build_adt_ctor<'a, 'gcx, 'tcx>(infcx: &infer::InferCtxt<'a, 'gcx, 'tcx>,
850 ctor_id: ast::NodeId,
851 fields: &[hir::StructField],
856 let gcx = tcx.global_tcx();
857 let def_id = tcx.hir().local_def_id(ctor_id);
858 let param_env = gcx.param_env(def_id);
860 // Normalize the sig.
861 let sig = gcx.fn_sig(def_id)
863 .expect("LBR in ADT constructor signature");
864 let sig = gcx.normalize_erasing_regions(param_env, sig);
866 let (adt_def, substs) = match sig.output().sty {
867 ty::Adt(adt_def, substs) => (adt_def, substs),
868 _ => bug!("unexpected type for ADT ctor {:?}", sig.output())
871 debug!("build_ctor: def_id={:?} sig={:?} fields={:?}", def_id, sig, fields);
873 let local_decls = local_decls_for_sig(&sig, span);
875 let source_info = SourceInfo {
877 scope: OUTERMOST_SOURCE_SCOPE
880 let variant_no = if adt_def.is_enum() {
881 adt_def.variant_index_with_id(def_id)
886 // return = ADT(arg0, arg1, ...); return
887 let start_block = BasicBlockData {
888 statements: vec![Statement {
890 kind: StatementKind::Assign(
891 Place::Local(RETURN_PLACE),
892 box Rvalue::Aggregate(
893 box AggregateKind::Adt(adt_def, variant_no, substs, None, None),
894 (1..sig.inputs().len()+1).map(|i| {
895 Operand::Move(Place::Local(Local::new(i)))
900 terminator: Some(Terminator {
902 kind: TerminatorKind::Return,
908 IndexVec::from_elem_n(start_block, 1),
909 IndexVec::from_elem_n(
910 SourceScopeData { span: span, parent_scope: None }, 1
912 ClearCrossCrate::Clear,