1 // Copyright 2015 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_data_structures::indexed_vec::Idx;
15 use hair::cx::to_ref::ToRef;
16 use hair::util::UserAnnotatedTyHelpers;
17 use rustc::hir::def::{Def, CtorKind};
18 use rustc::mir::interpret::GlobalId;
19 use rustc::ty::{self, AdtKind, Ty};
20 use rustc::ty::adjustment::{Adjustment, Adjust, AutoBorrow, AutoBorrowMutability};
21 use rustc::ty::cast::CastKind as TyCastKind;
23 use rustc::hir::def_id::LocalDefId;
24 use rustc::mir::{BorrowKind};
27 impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
28 type Output = Expr<'tcx>;
30 fn make_mirror<'a, 'gcx>(self, cx: &mut Cx<'a, 'gcx, 'tcx>) -> Expr<'tcx> {
31 let temp_lifetime = cx.region_scope_tree.temporary_scope(self.hir_id.local_id);
32 let expr_scope = region::Scope {
33 id: self.hir_id.local_id,
34 data: region::ScopeData::Node
37 debug!("Expr::make_mirror(): id={}, span={:?}", self.id, self.span);
39 let mut expr = make_mirror_unadjusted(cx, self);
41 // Now apply adjustments, if any.
42 for adjustment in cx.tables().expr_adjustments(self) {
43 debug!("make_mirror: expr={:?} applying adjustment={:?}",
46 expr = apply_adjustment(cx, self, expr, adjustment);
49 // Next, wrap this up in the expr's scope.
54 kind: ExprKind::Scope {
55 region_scope: expr_scope,
57 lint_level: cx.lint_level_of(self.id),
61 // Finally, create a destruction scope, if any.
62 if let Some(region_scope) =
63 cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id) {
68 kind: ExprKind::Scope {
71 lint_level: LintLevel::Inherited,
81 fn apply_adjustment<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
82 hir_expr: &'tcx hir::Expr,
84 adjustment: &Adjustment<'tcx>)
86 let Expr { temp_lifetime, mut span, .. } = expr;
87 let kind = match adjustment.kind {
88 Adjust::ReifyFnPointer => {
89 ExprKind::ReifyFnPointer { source: expr.to_ref() }
91 Adjust::UnsafeFnPointer => {
92 ExprKind::UnsafeFnPointer { source: expr.to_ref() }
94 Adjust::ClosureFnPointer => {
95 ExprKind::ClosureFnPointer { source: expr.to_ref() }
97 Adjust::NeverToAny => {
98 ExprKind::NeverToAny { source: expr.to_ref() }
100 Adjust::MutToConstPointer => {
101 ExprKind::Cast { source: expr.to_ref() }
103 Adjust::Deref(None) => {
104 // Adjust the span from the block, to the last expression of the
105 // block. This is a better span when returning a mutable reference
106 // with too short a lifetime. The error message will use the span
107 // from the assignment to the return place, which should only point
108 // at the returned value, not the entire function body.
110 // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
112 // // ^ error message points at this expression.
115 // We don't need to do this adjustment in the next match arm since
116 // deref coercions always start with a built-in deref.
117 if let ExprKind::Block { body } = expr.kind {
118 if let Some(ref last_expr) = body.expr {
119 span = last_expr.span;
123 ExprKind::Deref { arg: expr.to_ref() }
125 Adjust::Deref(Some(deref)) => {
126 let call = deref.method_call(cx.tcx(), expr.ty);
130 ty: cx.tcx.mk_ref(deref.region,
136 kind: ExprKind::Borrow {
137 region: deref.region,
138 borrow_kind: deref.mutbl.to_borrow_kind(),
143 overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
145 Adjust::Borrow(AutoBorrow::Ref(r, m)) => {
148 borrow_kind: m.to_borrow_kind(),
152 Adjust::Borrow(AutoBorrow::RawPtr(m)) => {
153 // Convert this to a suitable `&foo` and
154 // then an unsafe coercion. Limit the region to be just this
156 let region = ty::ReScope(region::Scope {
157 id: hir_expr.hir_id.local_id,
158 data: region::ScopeData::Node
160 let region = cx.tcx.mk_region(region);
163 ty: cx.tcx.mk_ref(region,
169 kind: ExprKind::Borrow {
171 borrow_kind: m.to_borrow_kind(),
175 let cast_expr = Expr {
177 ty: adjustment.target,
179 kind: ExprKind::Cast { source: expr.to_ref() }
182 // To ensure that both implicit and explicit coercions are
183 // handled the same way, we insert an extra layer of indirection here.
184 // For explicit casts (e.g. 'foo as *const T'), the source of the 'Use'
185 // will be an ExprKind::Hair with the appropriate cast expression. Here,
186 // we make our Use source the generated Cast from the original coercion.
188 // In both cases, this outer 'Use' ensures that the inner 'Cast' is handled by
189 // as_operand, not by as_rvalue - causing the cast result to be stored in a temporary.
190 // Ordinary, this is identical to using the cast directly as an rvalue. However, if the
191 // source of the cast was previously borrowed as mutable, storing the cast in a
192 // temporary gives the source a chance to expire before the cast is used. For
193 // structs with a self-referential *mut ptr, this allows assignment to work as
196 // For example, consider the type 'struct Foo { field: *mut Foo }',
197 // The method 'fn bar(&mut self) { self.field = self }'
198 // triggers a coercion from '&mut self' to '*mut self'. In order
199 // for the assignment to be valid, the implicit borrow
200 // of 'self' involved in the coercion needs to end before the local
201 // containing the '*mut T' is assigned to 'self.field' - otherwise,
202 // we end up trying to assign to 'self.field' while we have another mutable borrow
205 // We only need to worry about this kind of thing for coercions from refs to ptrs,
206 // since they get rid of a borrow implicitly.
207 ExprKind::Use { source: cast_expr.to_ref() }
210 // See the above comment for Adjust::Deref
211 if let ExprKind::Block { body } = expr.kind {
212 if let Some(ref last_expr) = body.expr {
213 span = last_expr.span;
217 ExprKind::Unsize { source: expr.to_ref() }
223 ty: adjustment.target,
229 fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
230 expr: &'tcx hir::Expr)
232 let expr_ty = cx.tables().expr_ty(expr);
233 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
235 let kind = match expr.node {
236 // Here comes the interesting stuff:
237 hir::ExprKind::MethodCall(_, method_span, ref args) => {
238 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
239 let expr = method_callee(cx, expr, method_span,None);
240 let args = args.iter()
251 hir::ExprKind::Call(ref fun, ref args) => {
252 if cx.tables().is_method_call(expr) {
253 // The callee is something implementing Fn, FnMut, or FnOnce.
254 // Find the actual method implementation being called and
255 // build the appropriate UFCS call expression with the
256 // callee-object as expr parameter.
258 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
260 let method = method_callee(cx, expr, fun.span,None);
262 let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
263 let tupled_args = Expr {
264 ty: cx.tcx.mk_tup(arg_tys),
267 kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
272 fun: method.to_ref(),
273 args: vec![fun.to_ref(), tupled_args.to_ref()],
277 let adt_data = if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) =
280 // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
281 expr_ty.ty_adt_def().and_then(|adt_def| {
283 Def::VariantCtor(variant_id, CtorKind::Fn) => {
284 Some((adt_def, adt_def.variant_index_with_id(variant_id)))
286 Def::StructCtor(_, CtorKind::Fn) |
287 Def::SelfCtor(..) => Some((adt_def, 0)),
294 if let Some((adt_def, index)) = adt_data {
295 let substs = cx.tables().node_substs(fun.hir_id);
297 let user_ty = cx.tables().user_substs(fun.hir_id)
298 .map(|user_substs| UserTypeAnnotation::AdtDef(adt_def, user_substs));
300 let field_refs = args.iter()
304 name: Field::new(idx),
312 variant_index: index,
319 ty: cx.tables().node_id_to_type(fun.hir_id),
328 hir::ExprKind::AddrOf(mutbl, ref expr) => {
329 let region = match expr_ty.sty {
330 ty::Ref(r, _, _) => r,
331 _ => span_bug!(expr.span, "type of & not region"),
335 borrow_kind: mutbl.to_borrow_kind(),
340 hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
342 hir::ExprKind::Assign(ref lhs, ref rhs) => {
349 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
350 if cx.tables().is_method_call(expr) {
351 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
361 hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
362 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
366 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
367 if cx.tables().is_method_call(expr) {
368 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
371 match (op.node, cx.constness) {
372 // FIXME(eddyb) use logical ops in constants when
373 // they can handle that kind of control-flow.
374 (hir::BinOpKind::And, hir::Constness::Const) => {
381 (hir::BinOpKind::Or, hir::Constness::Const) => {
389 (hir::BinOpKind::And, hir::Constness::NotConst) => {
390 ExprKind::LogicalOp {
396 (hir::BinOpKind::Or, hir::Constness::NotConst) => {
397 ExprKind::LogicalOp {
405 let op = bin_op(op.node);
416 hir::ExprKind::Index(ref lhs, ref index) => {
417 if cx.tables().is_method_call(expr) {
418 overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
422 index: index.to_ref(),
427 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
428 if cx.tables().is_method_call(expr) {
429 overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
431 ExprKind::Deref { arg: arg.to_ref() }
435 hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
436 if cx.tables().is_method_call(expr) {
437 overloaded_operator(cx, expr, vec![arg.to_ref()])
446 hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
447 if cx.tables().is_method_call(expr) {
448 overloaded_operator(cx, expr, vec![arg.to_ref()])
450 if let hir::ExprKind::Lit(ref lit) = arg.node {
452 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
464 hir::ExprKind::Struct(ref qpath, ref fields, ref base) => {
466 ty::Adt(adt, substs) => {
467 match adt.adt_kind() {
468 AdtKind::Struct | AdtKind::Union => {
473 user_ty: cx.user_substs_applied_to_adt(expr.hir_id, adt),
474 fields: field_refs(cx, fields),
475 base: base.as_ref().map(|base| {
478 field_types: cx.tables()
479 .fru_field_types()[expr.hir_id]
486 let def = match *qpath {
487 hir::QPath::Resolved(_, ref path) => path.def,
488 hir::QPath::TypeRelative(..) => Def::Err,
491 Def::Variant(variant_id) => {
492 assert!(base.is_none());
494 let index = adt.variant_index_with_id(variant_id);
497 variant_index: index,
499 user_ty: cx.user_substs_applied_to_adt(expr.hir_id, adt),
500 fields: field_refs(cx, fields),
505 span_bug!(expr.span, "unexpected def: {:?}", def);
513 "unexpected type for struct literal: {:?}",
519 hir::ExprKind::Closure(..) => {
520 let closure_ty = cx.tables().expr_ty(expr);
521 let (def_id, substs, movability) = match closure_ty.sty {
522 ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
523 ty::Generator(def_id, substs, movability) => {
524 (def_id, UpvarSubsts::Generator(substs), Some(movability))
527 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
530 let upvars = cx.tcx.with_freevars(expr.id, |freevars| {
532 .zip(substs.upvar_tys(def_id, cx.tcx))
533 .map(|(fv, ty)| capture_freevar(cx, expr, fv, ty))
544 hir::ExprKind::Path(ref qpath) => {
545 let def = cx.tables().qpath_def(qpath, expr.hir_id);
546 convert_path_expr(cx, expr, def)
549 hir::ExprKind::InlineAsm(ref asm, ref outputs, ref inputs) => {
550 ExprKind::InlineAsm {
552 outputs: outputs.to_ref(),
553 inputs: inputs.to_ref(),
557 // Now comes the rote stuff:
558 hir::ExprKind::Repeat(ref v, ref count) => {
559 let def_id = cx.tcx.hir.local_def_id(count.id);
560 let substs = Substs::identity_for_item(cx.tcx.global_tcx(), def_id);
561 let instance = ty::Instance::resolve(
567 let global_id = GlobalId {
571 let span = cx.tcx.def_span(def_id);
572 let count = match cx.tcx.at(span).const_eval(cx.param_env.and(global_id)) {
573 Ok(cv) => cv.unwrap_usize(cx.tcx),
575 e.report_as_error(cx.tcx.at(span), "could not evaluate array length");
585 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
586 hir::ExprKind::Break(dest, ref value) => {
587 match dest.target_id {
588 Ok(target_id) => ExprKind::Break {
589 label: region::Scope {
590 id: cx.tcx.hir.node_to_hir_id(target_id).local_id,
591 data: region::ScopeData::Node
593 value: value.to_ref(),
595 Err(err) => bug!("invalid loop id for break: {}", err)
598 hir::ExprKind::Continue(dest) => {
599 match dest.target_id {
600 Ok(loop_id) => ExprKind::Continue {
601 label: region::Scope {
602 id: cx.tcx.hir.node_to_hir_id(loop_id).local_id,
603 data: region::ScopeData::Node
606 Err(err) => bug!("invalid loop id for continue: {}", err)
609 hir::ExprKind::Match(ref discr, ref arms, _) => {
611 discriminant: discr.to_ref(),
612 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
615 hir::ExprKind::If(ref cond, ref then, ref otherwise) => {
617 condition: cond.to_ref(),
619 otherwise: otherwise.to_ref(),
622 hir::ExprKind::While(ref cond, ref body, _) => {
624 condition: Some(cond.to_ref()),
625 body: block::to_expr_ref(cx, body),
628 hir::ExprKind::Loop(ref body, _, _) => {
631 body: block::to_expr_ref(cx, body),
634 hir::ExprKind::Field(ref source, ..) => {
636 lhs: source.to_ref(),
637 name: Field::new(cx.tcx.field_index(expr.id, cx.tables)),
640 hir::ExprKind::Cast(ref source, _) => {
641 // Check to see if this cast is a "coercion cast", where the cast is actually done
642 // using a coercion (or is a no-op).
643 if let Some(&TyCastKind::CoercionCast) = cx.tables()
645 .get(source.hir_id) {
646 // Convert the lexpr to a vexpr.
647 ExprKind::Use { source: source.to_ref() }
649 // check whether this is casting an enum variant discriminant
650 // to prevent cycles, we refer to the discriminant initializer
651 // which is always an integer and thus doesn't need to know the
652 // enum's layout (or its tag type) to compute it during const eval
656 // B = A as isize + 4,
658 // The correct solution would be to add symbolic computations to miri,
659 // so we wouldn't have to compute and store the actual value
660 let var = if let hir::ExprKind::Path(ref qpath) = source.node {
661 let def = cx.tables().qpath_def(qpath, source.hir_id);
664 .node_id_to_type(source.hir_id)
666 .and_then(|adt_def| {
668 Def::VariantCtor(variant_id, CtorKind::Const) => {
669 let idx = adt_def.variant_index_with_id(variant_id);
670 let (d, o) = adt_def.discriminant_def_for_variant(idx);
671 use rustc::ty::util::IntTypeExt;
672 let ty = adt_def.repr.discr_type();
673 let ty = ty.to_ty(cx.tcx());
682 let source = if let Some((did, offset, ty)) = var {
683 let mk_const = |literal| Expr {
687 kind: ExprKind::Literal { literal, user_ty: None },
689 let offset = mk_const(ty::Const::from_bits(
692 cx.param_env.and(ty),
696 // in case we are offsetting from a computed discriminant
697 // and not the beginning of discriminants (which is always `0`)
698 let substs = Substs::identity_for_item(cx.tcx(), did);
699 let lhs = mk_const(ty::Const::unevaluated(cx.tcx(), did, substs, ty));
700 let bin = ExprKind::Binary {
717 ExprKind::Cast { source }
720 hir::ExprKind::Type(ref source, ref ty) => {
721 let user_provided_tys = cx.tables.user_provided_tys();
722 let user_ty = UserTypeAnnotation::Ty(
726 "{:?} not found in user_provided_tys, source: {:?}",
731 if source.is_place_expr() {
732 ExprKind::PlaceTypeAscription {
733 source: source.to_ref(),
737 ExprKind::ValueTypeAscription {
738 source: source.to_ref(),
743 hir::ExprKind::Box(ref value) => {
745 value: value.to_ref(),
748 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
749 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
751 hir::ExprKind::Yield(ref v) => ExprKind::Yield { value: v.to_ref() },
762 fn user_substs_applied_to_def(
763 cx: &mut Cx<'a, 'gcx, 'tcx>,
766 ) -> Option<UserTypeAnnotation<'tcx>> {
768 // A reference to something callable -- e.g., a fn, method, or
769 // a tuple-struct or tuple-variant. This has the type of a
770 // `Fn` but with the user-given substitutions.
773 Def::StructCtor(_, CtorKind::Fn) |
774 Def::VariantCtor(_, CtorKind::Fn) =>
775 Some(UserTypeAnnotation::FnDef(def.def_id(), cx.tables().user_substs(hir_id)?)),
777 Def::Const(_def_id) |
778 Def::AssociatedConst(_def_id) =>
779 bug!("unimplemented"),
781 // A unit struct/variant which is used as a value (e.g.,
782 // `None`). This has the type of the enum/struct that defines
783 // this variant -- but with the substitutions given by the
785 Def::StructCtor(_def_id, CtorKind::Const) |
786 Def::VariantCtor(_def_id, CtorKind::Const) =>
787 cx.user_substs_applied_to_ty_of_hir_id(hir_id),
789 // `Self` is used in expression as a tuple struct constructor or an unit struct constructor
791 cx.user_substs_applied_to_ty_of_hir_id(hir_id),
794 bug!("user_substs_applied_to_def: unexpected def {:?} at {:?}", def, hir_id)
798 fn method_callee<'a, 'gcx, 'tcx>(
799 cx: &mut Cx<'a, 'gcx, 'tcx>,
802 overloaded_callee: Option<(DefId, &'tcx Substs<'tcx>)>,
804 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
805 let (def_id, substs, user_ty) = match overloaded_callee {
806 Some((def_id, substs)) => (def_id, substs, None),
808 let type_dependent_defs = cx.tables().type_dependent_defs();
809 let def = type_dependent_defs
812 span_bug!(expr.span, "no type-dependent def for method callee")
814 let user_ty = user_substs_applied_to_def(cx, expr.hir_id, def);
815 (def.def_id(), cx.tables().node_substs(expr.hir_id), user_ty)
818 let ty = cx.tcx().mk_fn_def(def_id, substs);
823 kind: ExprKind::Literal {
824 literal: ty::Const::zero_sized(cx.tcx(), ty),
830 trait ToBorrowKind { fn to_borrow_kind(&self) -> BorrowKind; }
832 impl ToBorrowKind for AutoBorrowMutability {
833 fn to_borrow_kind(&self) -> BorrowKind {
834 use rustc::ty::adjustment::AllowTwoPhase;
836 AutoBorrowMutability::Mutable { allow_two_phase_borrow } =>
837 BorrowKind::Mut { allow_two_phase_borrow: match allow_two_phase_borrow {
838 AllowTwoPhase::Yes => true,
839 AllowTwoPhase::No => false
841 AutoBorrowMutability::Immutable =>
847 impl ToBorrowKind for hir::Mutability {
848 fn to_borrow_kind(&self) -> BorrowKind {
850 hir::MutMutable => BorrowKind::Mut { allow_two_phase_borrow: false },
851 hir::MutImmutable => BorrowKind::Shared,
856 fn convert_arm<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
858 patterns: arm.pats.iter().map(|p| cx.pattern_from_hir(p)).collect(),
859 guard: match arm.guard {
860 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
863 body: arm.body.to_ref(),
865 lint_level: LintLevel::Inherited,
869 fn convert_path_expr<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
870 expr: &'tcx hir::Expr,
873 let substs = cx.tables().node_substs(expr.hir_id);
875 // A regular function, constructor function or a constant.
878 Def::StructCtor(_, CtorKind::Fn) |
879 Def::VariantCtor(_, CtorKind::Fn) |
880 Def::SelfCtor(..) => {
881 let user_ty = user_substs_applied_to_def(cx, expr.hir_id, &def);
883 literal: ty::Const::zero_sized(
885 cx.tables().node_id_to_type(expr.hir_id),
892 Def::AssociatedConst(def_id) => ExprKind::Literal {
893 literal: ty::Const::unevaluated(
897 cx.tables().node_id_to_type(expr.hir_id),
899 user_ty: None, // FIXME(#47184) -- user given type annot on constants
902 Def::StructCtor(def_id, CtorKind::Const) |
903 Def::VariantCtor(def_id, CtorKind::Const) => {
904 match cx.tables().node_id_to_type(expr.hir_id).sty {
905 // A unit struct/variant which is used as a value.
906 // We return a completely different ExprKind here to account for this special case.
907 ty::Adt(adt_def, substs) => {
910 variant_index: adt_def.variant_index_with_id(def_id),
912 user_ty: cx.user_substs_applied_to_adt(expr.hir_id, adt_def),
917 ref sty => bug!("unexpected sty: {:?}", sty),
921 Def::Static(node_id, _) => ExprKind::StaticRef { id: node_id },
923 Def::Local(..) | Def::Upvar(..) => convert_var(cx, expr, def),
925 _ => span_bug!(expr.span, "def `{:?}` not yet implemented", def),
929 fn convert_var<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
930 expr: &'tcx hir::Expr,
933 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
936 Def::Local(id) => ExprKind::VarRef { id },
938 Def::Upvar(var_id, index, closure_expr_id) => {
939 debug!("convert_var(upvar({:?}, {:?}, {:?}))",
943 let var_hir_id = cx.tcx.hir.node_to_hir_id(var_id);
944 let var_ty = cx.tables().node_id_to_type(var_hir_id);
946 // FIXME free regions in closures are not right
947 let closure_ty = cx.tables()
948 .node_id_to_type(cx.tcx.hir.node_to_hir_id(closure_expr_id));
950 // FIXME we're just hard-coding the idea that the
951 // signature will be &self or &mut self and hence will
952 // have a bound region with number 0
953 let closure_def_id = cx.tcx.hir.local_def_id(closure_expr_id);
954 let region = ty::ReFree(ty::FreeRegion {
955 scope: closure_def_id,
956 bound_region: ty::BoundRegion::BrAnon(0),
958 let region = cx.tcx.mk_region(region);
960 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.sty {
961 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
962 ty::ClosureKind::Fn => {
963 let ref_closure_ty = cx.tcx.mk_ref(region,
966 mutbl: hir::MutImmutable,
970 temp_lifetime: temp_lifetime,
972 kind: ExprKind::Deref {
977 kind: ExprKind::SelfRef,
983 ty::ClosureKind::FnMut => {
984 let ref_closure_ty = cx.tcx.mk_ref(region,
987 mutbl: hir::MutMutable,
993 kind: ExprKind::Deref {
998 kind: ExprKind::SelfRef,
1003 ty::ClosureKind::FnOnce => {
1008 kind: ExprKind::SelfRef,
1017 kind: ExprKind::SelfRef,
1021 // at this point we have `self.n`, which loads up the upvar
1022 let field_kind = ExprKind::Field {
1023 lhs: self_expr.to_ref(),
1024 name: Field::new(index),
1027 // ...but the upvar might be an `&T` or `&mut T` capture, at which
1028 // point we need an implicit deref
1029 let upvar_id = ty::UpvarId {
1031 closure_expr_id: LocalDefId::from_def_id(closure_def_id),
1033 match cx.tables().upvar_capture(upvar_id) {
1034 ty::UpvarCapture::ByValue => field_kind,
1035 ty::UpvarCapture::ByRef(borrow) => {
1039 ty: cx.tcx.mk_ref(borrow.region,
1042 mutbl: borrow.kind.to_mutbl_lossy(),
1052 _ => span_bug!(expr.span, "type of & not region"),
1057 fn bin_op(op: hir::BinOpKind) -> BinOp {
1059 hir::BinOpKind::Add => BinOp::Add,
1060 hir::BinOpKind::Sub => BinOp::Sub,
1061 hir::BinOpKind::Mul => BinOp::Mul,
1062 hir::BinOpKind::Div => BinOp::Div,
1063 hir::BinOpKind::Rem => BinOp::Rem,
1064 hir::BinOpKind::BitXor => BinOp::BitXor,
1065 hir::BinOpKind::BitAnd => BinOp::BitAnd,
1066 hir::BinOpKind::BitOr => BinOp::BitOr,
1067 hir::BinOpKind::Shl => BinOp::Shl,
1068 hir::BinOpKind::Shr => BinOp::Shr,
1069 hir::BinOpKind::Eq => BinOp::Eq,
1070 hir::BinOpKind::Lt => BinOp::Lt,
1071 hir::BinOpKind::Le => BinOp::Le,
1072 hir::BinOpKind::Ne => BinOp::Ne,
1073 hir::BinOpKind::Ge => BinOp::Ge,
1074 hir::BinOpKind::Gt => BinOp::Gt,
1075 _ => bug!("no equivalent for ast binop {:?}", op),
1079 fn overloaded_operator<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1080 expr: &'tcx hir::Expr,
1081 args: Vec<ExprRef<'tcx>>)
1083 let fun = method_callee(cx, expr, expr.span, None);
1088 from_hir_call: false,
1092 fn overloaded_place<'a, 'gcx, 'tcx>(
1093 cx: &mut Cx<'a, 'gcx, 'tcx>,
1094 expr: &'tcx hir::Expr,
1096 overloaded_callee: Option<(DefId, &'tcx Substs<'tcx>)>,
1097 args: Vec<ExprRef<'tcx>>,
1098 ) -> ExprKind<'tcx> {
1099 // For an overloaded *x or x[y] expression of type T, the method
1100 // call returns an &T and we must add the deref so that the types
1101 // line up (this is because `*x` and `x[y]` represent places):
1103 let recv_ty = match args[0] {
1104 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
1105 ExprRef::Mirror(ref e) => e.ty
1108 // Reconstruct the output assuming it's a reference with the
1109 // same region and mutability as the receiver. This holds for
1110 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
1111 let (region, mutbl) = match recv_ty.sty {
1112 ty::Ref(region, _, mutbl) => (region, mutbl),
1113 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
1115 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut {
1120 // construct the complete expression `foo()` for the overloaded call,
1121 // which will yield the &T type
1122 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
1123 let fun = method_callee(cx, expr, expr.span, overloaded_callee);
1124 let ref_expr = Expr {
1128 kind: ExprKind::Call {
1132 from_hir_call: false,
1136 // construct and return a deref wrapper `*foo()`
1137 ExprKind::Deref { arg: ref_expr.to_ref() }
1140 fn capture_freevar<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1141 closure_expr: &'tcx hir::Expr,
1142 freevar: &hir::Freevar,
1143 freevar_ty: Ty<'tcx>)
1145 let var_hir_id = cx.tcx.hir.node_to_hir_id(freevar.var_id());
1146 let upvar_id = ty::UpvarId {
1148 closure_expr_id: cx.tcx.hir.local_def_id(closure_expr.id).to_local(),
1150 let upvar_capture = cx.tables().upvar_capture(upvar_id);
1151 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1152 let var_ty = cx.tables().node_id_to_type(var_hir_id);
1153 let captured_var = Expr {
1156 span: closure_expr.span,
1157 kind: convert_var(cx, closure_expr, freevar.def),
1159 match upvar_capture {
1160 ty::UpvarCapture::ByValue => captured_var.to_ref(),
1161 ty::UpvarCapture::ByRef(upvar_borrow) => {
1162 let borrow_kind = match upvar_borrow.kind {
1163 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1164 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1165 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false }
1170 span: closure_expr.span,
1171 kind: ExprKind::Borrow {
1172 region: upvar_borrow.region,
1174 arg: captured_var.to_ref(),
1181 /// Converts a list of named fields (i.e. for struct-like struct/enum ADTs) into FieldExprRef.
1182 fn field_refs<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1183 fields: &'tcx [hir::Field])
1184 -> Vec<FieldExprRef<'tcx>> {
1188 name: Field::new(cx.tcx.field_index(field.id, cx.tables)),
1189 expr: field.expr.to_ref(),