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 rustc::hir::def::{Def, CtorKind};
17 use rustc::mir::interpret::GlobalId;
18 use rustc::ty::{self, AdtKind, Ty};
19 use rustc::ty::adjustment::{Adjustment, Adjust, AutoBorrow, AutoBorrowMutability};
20 use rustc::ty::cast::CastKind as TyCastKind;
22 use rustc::hir::def_id::LocalDefId;
23 use rustc::mir::{BorrowKind};
25 impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
26 type Output = Expr<'tcx>;
28 fn make_mirror<'a, 'gcx>(self, cx: &mut Cx<'a, 'gcx, 'tcx>) -> Expr<'tcx> {
29 let temp_lifetime = cx.region_scope_tree.temporary_scope(self.hir_id.local_id);
30 let expr_scope = region::Scope::Node(self.hir_id.local_id);
32 debug!("Expr::make_mirror(): id={}, span={:?}", self.id, self.span);
34 let mut expr = make_mirror_unadjusted(cx, self);
36 // Now apply adjustments, if any.
37 for adjustment in cx.tables().expr_adjustments(self) {
38 debug!("make_mirror: expr={:?} applying adjustment={:?}",
41 expr = apply_adjustment(cx, self, expr, adjustment);
44 // Next, wrap this up in the expr's scope.
49 kind: ExprKind::Scope {
50 region_scope: expr_scope,
52 lint_level: cx.lint_level_of(self.id),
56 // Finally, create a destruction scope, if any.
57 if let Some(region_scope) =
58 cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id) {
63 kind: ExprKind::Scope {
66 lint_level: LintLevel::Inherited,
76 fn apply_adjustment<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
77 hir_expr: &'tcx hir::Expr,
79 adjustment: &Adjustment<'tcx>)
81 let Expr { temp_lifetime, mut span, .. } = expr;
82 let kind = match adjustment.kind {
83 Adjust::ReifyFnPointer => {
84 ExprKind::ReifyFnPointer { source: expr.to_ref() }
86 Adjust::UnsafeFnPointer => {
87 ExprKind::UnsafeFnPointer { source: expr.to_ref() }
89 Adjust::ClosureFnPointer => {
90 ExprKind::ClosureFnPointer { source: expr.to_ref() }
92 Adjust::NeverToAny => {
93 ExprKind::NeverToAny { source: expr.to_ref() }
95 Adjust::MutToConstPointer => {
96 ExprKind::Cast { source: expr.to_ref() }
98 Adjust::Deref(None) => {
99 // Adjust the span from the block, to the last expression of the
100 // block. This is a better span when returning a mutable reference
101 // with too short a lifetime. The error message will use the span
102 // from the assignment to the return place, which should only point
103 // at the returned value, not the entire function body.
105 // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
107 // // ^ error message points at this expression.
110 // We don't need to do this adjustment in the next match arm since
111 // deref coercions always start with a built-in deref.
112 if let ExprKind::Block { body } = expr.kind {
113 if let Some(ref last_expr) = body.expr {
114 span = last_expr.span;
118 ExprKind::Deref { arg: expr.to_ref() }
120 Adjust::Deref(Some(deref)) => {
121 let call = deref.method_call(cx.tcx(), expr.ty);
125 ty: cx.tcx.mk_ref(deref.region,
131 kind: ExprKind::Borrow {
132 region: deref.region,
133 borrow_kind: deref.mutbl.to_borrow_kind(),
138 overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
140 Adjust::Borrow(AutoBorrow::Ref(r, m)) => {
143 borrow_kind: m.to_borrow_kind(),
147 Adjust::Borrow(AutoBorrow::RawPtr(m)) => {
148 // Convert this to a suitable `&foo` and
149 // then an unsafe coercion. Limit the region to be just this
151 let region = ty::ReScope(region::Scope::Node(hir_expr.hir_id.local_id));
152 let region = cx.tcx.mk_region(region);
155 ty: cx.tcx.mk_ref(region,
161 kind: ExprKind::Borrow {
163 borrow_kind: m.to_borrow_kind(),
167 let cast_expr = Expr {
169 ty: adjustment.target,
171 kind: ExprKind::Cast { source: expr.to_ref() }
174 // To ensure that both implicit and explicit coercions are
175 // handled the same way, we insert an extra layer of indirection here.
176 // For explicit casts (e.g. 'foo as *const T'), the source of the 'Use'
177 // will be an ExprKind::Hair with the appropriate cast expression. Here,
178 // we make our Use source the generated Cast from the original coercion.
180 // In both cases, this outer 'Use' ensures that the inner 'Cast' is handled by
181 // as_operand, not by as_rvalue - causing the cast result to be stored in a temporary.
182 // Ordinary, this is identical to using the cast directly as an rvalue. However, if the
183 // source of the cast was previously borrowed as mutable, storing the cast in a
184 // temporary gives the source a chance to expire before the cast is used. For
185 // structs with a self-referential *mut ptr, this allows assignment to work as
188 // For example, consider the type 'struct Foo { field: *mut Foo }',
189 // The method 'fn bar(&mut self) { self.field = self }'
190 // triggers a coercion from '&mut self' to '*mut self'. In order
191 // for the assignment to be valid, the implicit borrow
192 // of 'self' involved in the coercion needs to end before the local
193 // containing the '*mut T' is assigned to 'self.field' - otherwise,
194 // we end up trying to assign to 'self.field' while we have another mutable borrow
197 // We only need to worry about this kind of thing for coercions from refs to ptrs,
198 // since they get rid of a borrow implicitly.
199 ExprKind::Use { source: cast_expr.to_ref() }
202 // See the above comment for Adjust::Deref
203 if let ExprKind::Block { body } = expr.kind {
204 if let Some(ref last_expr) = body.expr {
205 span = last_expr.span;
209 ExprKind::Unsize { source: expr.to_ref() }
215 ty: adjustment.target,
221 fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
222 expr: &'tcx hir::Expr)
224 let expr_ty = cx.tables().expr_ty(expr);
225 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
227 let kind = match expr.node {
228 // Here comes the interesting stuff:
229 hir::ExprKind::MethodCall(.., ref args) => {
230 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
231 let expr = method_callee(cx, expr, None);
232 let args = args.iter()
242 hir::ExprKind::Call(ref fun, ref args) => {
243 if cx.tables().is_method_call(expr) {
244 // The callee is something implementing Fn, FnMut, or FnOnce.
245 // Find the actual method implementation being called and
246 // build the appropriate UFCS call expression with the
247 // callee-object as expr parameter.
249 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
251 let method = method_callee(cx, expr, None);
253 let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
254 let tupled_args = Expr {
255 ty: cx.tcx.mk_tup(arg_tys),
258 kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
263 fun: method.to_ref(),
264 args: vec![fun.to_ref(), tupled_args.to_ref()],
267 let adt_data = if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) =
270 // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
271 expr_ty.ty_adt_def().and_then(|adt_def| {
273 Def::VariantCtor(variant_id, CtorKind::Fn) => {
274 Some((adt_def, adt_def.variant_index_with_id(variant_id)))
276 Def::StructCtor(_, CtorKind::Fn) => Some((adt_def, 0)),
283 if let Some((adt_def, index)) = adt_data {
284 let substs = cx.tables().node_substs(fun.hir_id);
286 let user_ty = cx.tables().user_substs(fun.hir_id)
288 user_substs.unchecked_map(|user_substs| {
289 // Here, we just pair an `AdtDef` with the
290 // `user_substs`, so no new types etc are introduced.
291 cx.tcx().mk_adt(adt_def, user_substs)
295 let field_refs = args.iter()
299 name: Field::new(idx),
307 variant_index: index,
314 ty: cx.tables().node_id_to_type(fun.hir_id),
322 hir::ExprKind::AddrOf(mutbl, ref expr) => {
323 let region = match expr_ty.sty {
324 ty::Ref(r, _, _) => r,
325 _ => span_bug!(expr.span, "type of & not region"),
329 borrow_kind: mutbl.to_borrow_kind(),
334 hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
336 hir::ExprKind::Assign(ref lhs, ref rhs) => {
343 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
344 if cx.tables().is_method_call(expr) {
345 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
355 hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
356 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
360 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
361 if cx.tables().is_method_call(expr) {
362 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
365 match (op.node, cx.constness) {
366 // FIXME(eddyb) use logical ops in constants when
367 // they can handle that kind of control-flow.
368 (hir::BinOpKind::And, hir::Constness::Const) => {
375 (hir::BinOpKind::Or, hir::Constness::Const) => {
383 (hir::BinOpKind::And, hir::Constness::NotConst) => {
384 ExprKind::LogicalOp {
390 (hir::BinOpKind::Or, hir::Constness::NotConst) => {
391 ExprKind::LogicalOp {
399 let op = bin_op(op.node);
410 hir::ExprKind::Index(ref lhs, ref index) => {
411 if cx.tables().is_method_call(expr) {
412 overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
416 index: index.to_ref(),
421 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
422 if cx.tables().is_method_call(expr) {
423 overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
425 ExprKind::Deref { arg: arg.to_ref() }
429 hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
430 if cx.tables().is_method_call(expr) {
431 overloaded_operator(cx, expr, vec![arg.to_ref()])
440 hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
441 if cx.tables().is_method_call(expr) {
442 overloaded_operator(cx, expr, vec![arg.to_ref()])
444 if let hir::ExprKind::Lit(ref lit) = arg.node {
446 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
458 hir::ExprKind::Struct(ref qpath, ref fields, ref base) => {
460 ty::Adt(adt, substs) => {
461 match adt.adt_kind() {
462 AdtKind::Struct | AdtKind::Union => {
467 user_ty: user_annotated_ty_for_adt(cx, expr.hir_id, adt),
468 fields: field_refs(cx, fields),
469 base: base.as_ref().map(|base| {
472 field_types: cx.tables()
473 .fru_field_types()[expr.hir_id]
480 let def = match *qpath {
481 hir::QPath::Resolved(_, ref path) => path.def,
482 hir::QPath::TypeRelative(..) => Def::Err,
485 Def::Variant(variant_id) => {
486 assert!(base.is_none());
488 let index = adt.variant_index_with_id(variant_id);
491 variant_index: index,
493 user_ty: user_annotated_ty_for_adt(cx, expr.hir_id, adt),
494 fields: field_refs(cx, fields),
499 span_bug!(expr.span, "unexpected def: {:?}", def);
507 "unexpected type for struct literal: {:?}",
513 hir::ExprKind::Closure(..) => {
514 let closure_ty = cx.tables().expr_ty(expr);
515 let (def_id, substs, movability) = match closure_ty.sty {
516 ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
517 ty::Generator(def_id, substs, movability) => {
518 (def_id, UpvarSubsts::Generator(substs), Some(movability))
521 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
524 let upvars = cx.tcx.with_freevars(expr.id, |freevars| {
526 .zip(substs.upvar_tys(def_id, cx.tcx))
527 .map(|(fv, ty)| capture_freevar(cx, expr, fv, ty))
538 hir::ExprKind::Path(ref qpath) => {
539 let def = cx.tables().qpath_def(qpath, expr.hir_id);
540 convert_path_expr(cx, expr, def)
543 hir::ExprKind::InlineAsm(ref asm, ref outputs, ref inputs) => {
544 ExprKind::InlineAsm {
546 outputs: outputs.to_ref(),
547 inputs: inputs.to_ref(),
551 // Now comes the rote stuff:
552 hir::ExprKind::Repeat(ref v, ref count) => {
553 let def_id = cx.tcx.hir.local_def_id(count.id);
554 let substs = Substs::identity_for_item(cx.tcx.global_tcx(), def_id);
555 let instance = ty::Instance::resolve(
561 let global_id = GlobalId {
565 let span = cx.tcx.def_span(def_id);
566 let count = match cx.tcx.at(span).const_eval(cx.param_env.and(global_id)) {
567 Ok(cv) => cv.unwrap_usize(cx.tcx),
569 e.report_as_error(cx.tcx.at(span), "could not evaluate array length");
579 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
580 hir::ExprKind::Break(dest, ref value) => {
581 match dest.target_id {
582 Ok(target_id) => ExprKind::Break {
583 label: region::Scope::Node(cx.tcx.hir.node_to_hir_id(target_id).local_id),
584 value: value.to_ref(),
586 Err(err) => bug!("invalid loop id for break: {}", err)
589 hir::ExprKind::Continue(dest) => {
590 match dest.target_id {
591 Ok(loop_id) => ExprKind::Continue {
592 label: region::Scope::Node(cx.tcx.hir.node_to_hir_id(loop_id).local_id),
594 Err(err) => bug!("invalid loop id for continue: {}", err)
597 hir::ExprKind::Match(ref discr, ref arms, _) => {
599 discriminant: discr.to_ref(),
600 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
603 hir::ExprKind::If(ref cond, ref then, ref otherwise) => {
605 condition: cond.to_ref(),
607 otherwise: otherwise.to_ref(),
610 hir::ExprKind::While(ref cond, ref body, _) => {
612 condition: Some(cond.to_ref()),
613 body: block::to_expr_ref(cx, body),
616 hir::ExprKind::Loop(ref body, _, _) => {
619 body: block::to_expr_ref(cx, body),
622 hir::ExprKind::Field(ref source, ..) => {
624 lhs: source.to_ref(),
625 name: Field::new(cx.tcx.field_index(expr.id, cx.tables)),
628 hir::ExprKind::Cast(ref source, _) => {
629 // Check to see if this cast is a "coercion cast", where the cast is actually done
630 // using a coercion (or is a no-op).
631 if let Some(&TyCastKind::CoercionCast) = cx.tables()
633 .get(source.hir_id) {
634 // Convert the lexpr to a vexpr.
635 ExprKind::Use { source: source.to_ref() }
637 // check whether this is casting an enum variant discriminant
638 // to prevent cycles, we refer to the discriminant initializer
639 // which is always an integer and thus doesn't need to know the
640 // enum's layout (or its tag type) to compute it during const eval
644 // B = A as isize + 4,
646 // The correct solution would be to add symbolic computations to miri,
647 // so we wouldn't have to compute and store the actual value
648 let var = if let hir::ExprKind::Path(ref qpath) = source.node {
649 let def = cx.tables().qpath_def(qpath, source.hir_id);
652 .node_id_to_type(source.hir_id)
654 .and_then(|adt_def| {
656 Def::VariantCtor(variant_id, CtorKind::Const) => {
657 let idx = adt_def.variant_index_with_id(variant_id);
658 let (d, o) = adt_def.discriminant_def_for_variant(idx);
659 use rustc::ty::util::IntTypeExt;
660 let ty = adt_def.repr.discr_type();
661 let ty = ty.to_ty(cx.tcx());
670 let source = if let Some((did, offset, ty)) = var {
671 let mk_const = |literal| Expr {
675 kind: ExprKind::Literal { literal, user_ty: None },
677 let offset = mk_const(ty::Const::from_bits(
680 cx.param_env.and(ty),
684 // in case we are offsetting from a computed discriminant
685 // and not the beginning of discriminants (which is always `0`)
686 let substs = Substs::identity_for_item(cx.tcx(), did);
687 let lhs = mk_const(ty::Const::unevaluated(cx.tcx(), did, substs, ty));
688 let bin = ExprKind::Binary {
705 ExprKind::Cast { source }
708 hir::ExprKind::Type(ref source, _) => return source.make_mirror(cx),
709 hir::ExprKind::Box(ref value) => {
711 value: value.to_ref(),
714 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
715 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
717 hir::ExprKind::Yield(ref v) => ExprKind::Yield { value: v.to_ref() },
728 fn user_annotated_ty_for_def(
729 cx: &mut Cx<'a, 'gcx, 'tcx>,
732 ) -> Option<CanonicalTy<'tcx>> {
734 // A reference to something callable -- e.g., a fn, method, or
735 // a tuple-struct or tuple-variant. This has the type of a
736 // `Fn` but with the user-given substitutions.
739 Def::StructCtor(_, CtorKind::Fn) |
740 Def::VariantCtor(_, CtorKind::Fn) =>
741 Some(cx.tables().user_substs(hir_id)?.unchecked_map(|user_substs| {
742 // Here, we just pair a `DefId` with the
743 // `user_substs`, so no new types etc are introduced.
744 cx.tcx().mk_fn_def(def.def_id(), user_substs)
747 Def::Const(_def_id) |
748 Def::AssociatedConst(_def_id) =>
749 bug!("unimplemented"),
751 // A unit struct/variant which is used as a value (e.g.,
752 // `None`). This has the type of the enum/struct that defines
753 // this variant -- but with the substitutions given by the
755 Def::StructCtor(_def_id, CtorKind::Const) |
756 Def::VariantCtor(_def_id, CtorKind::Const) =>
757 match &cx.tables().node_id_to_type(hir_id).sty {
758 ty::Adt(adt_def, _) => user_annotated_ty_for_adt(cx, hir_id, adt_def),
759 sty => bug!("unexpected sty: {:?}", sty),
763 bug!("user_annotated_ty_for_def: unexpected def {:?} at {:?}", def, hir_id)
767 fn user_annotated_ty_for_adt(
768 cx: &mut Cx<'a, 'gcx, 'tcx>,
770 adt_def: &'tcx AdtDef,
771 ) -> Option<CanonicalTy<'tcx>> {
772 let user_substs = cx.tables().user_substs(hir_id)?;
773 Some(user_substs.unchecked_map(|user_substs| {
774 // Here, we just pair an `AdtDef` with the
775 // `user_substs`, so no new types etc are introduced.
776 cx.tcx().mk_adt(adt_def, user_substs)
780 fn method_callee<'a, 'gcx, 'tcx>(
781 cx: &mut Cx<'a, 'gcx, 'tcx>,
783 overloaded_callee: Option<(DefId, &'tcx Substs<'tcx>)>,
785 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
786 let (def_id, substs, user_ty) = match overloaded_callee {
787 Some((def_id, substs)) => (def_id, substs, None),
789 let type_dependent_defs = cx.tables().type_dependent_defs();
790 let def = type_dependent_defs
793 span_bug!(expr.span, "no type-dependent def for method callee")
795 let user_ty = user_annotated_ty_for_def(cx, expr.hir_id, def);
796 (def.def_id(), cx.tables().node_substs(expr.hir_id), user_ty)
799 let ty = cx.tcx().mk_fn_def(def_id, substs);
804 kind: ExprKind::Literal {
805 literal: ty::Const::zero_sized(cx.tcx(), ty),
811 trait ToBorrowKind { fn to_borrow_kind(&self) -> BorrowKind; }
813 impl ToBorrowKind for AutoBorrowMutability {
814 fn to_borrow_kind(&self) -> BorrowKind {
815 use rustc::ty::adjustment::AllowTwoPhase;
817 AutoBorrowMutability::Mutable { allow_two_phase_borrow } =>
818 BorrowKind::Mut { allow_two_phase_borrow: match allow_two_phase_borrow {
819 AllowTwoPhase::Yes => true,
820 AllowTwoPhase::No => false
822 AutoBorrowMutability::Immutable =>
828 impl ToBorrowKind for hir::Mutability {
829 fn to_borrow_kind(&self) -> BorrowKind {
831 hir::MutMutable => BorrowKind::Mut { allow_two_phase_borrow: false },
832 hir::MutImmutable => BorrowKind::Shared,
837 fn convert_arm<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
839 patterns: arm.pats.iter().map(|p| cx.pattern_from_hir(p)).collect(),
840 guard: arm.guard.to_ref(),
841 body: arm.body.to_ref(),
843 lint_level: LintLevel::Inherited,
847 fn convert_path_expr<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
848 expr: &'tcx hir::Expr,
851 let substs = cx.tables().node_substs(expr.hir_id);
853 // A regular function, constructor function or a constant.
856 Def::StructCtor(_, CtorKind::Fn) |
857 Def::VariantCtor(_, CtorKind::Fn) => {
858 let user_ty = user_annotated_ty_for_def(cx, expr.hir_id, &def);
860 literal: ty::Const::zero_sized(
862 cx.tables().node_id_to_type(expr.hir_id),
869 Def::AssociatedConst(def_id) => ExprKind::Literal {
870 literal: ty::Const::unevaluated(
874 cx.tables().node_id_to_type(expr.hir_id),
876 user_ty: None, // FIXME(#47184) -- user given type annot on constants
879 Def::StructCtor(def_id, CtorKind::Const) |
880 Def::VariantCtor(def_id, CtorKind::Const) => {
881 match cx.tables().node_id_to_type(expr.hir_id).sty {
882 // A unit struct/variant which is used as a value.
883 // We return a completely different ExprKind here to account for this special case.
884 ty::Adt(adt_def, substs) => {
887 variant_index: adt_def.variant_index_with_id(def_id),
889 user_ty: user_annotated_ty_for_adt(cx, expr.hir_id, adt_def),
894 ref sty => bug!("unexpected sty: {:?}", sty),
898 Def::Static(node_id, _) => ExprKind::StaticRef { id: node_id },
900 Def::Local(..) | Def::Upvar(..) => convert_var(cx, expr, def),
902 _ => span_bug!(expr.span, "def `{:?}` not yet implemented", def),
906 fn convert_var<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
907 expr: &'tcx hir::Expr,
910 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
913 Def::Local(id) => ExprKind::VarRef { id },
915 Def::Upvar(var_id, index, closure_expr_id) => {
916 debug!("convert_var(upvar({:?}, {:?}, {:?}))",
920 let var_hir_id = cx.tcx.hir.node_to_hir_id(var_id);
921 let var_ty = cx.tables().node_id_to_type(var_hir_id);
923 // FIXME free regions in closures are not right
924 let closure_ty = cx.tables()
925 .node_id_to_type(cx.tcx.hir.node_to_hir_id(closure_expr_id));
927 // FIXME we're just hard-coding the idea that the
928 // signature will be &self or &mut self and hence will
929 // have a bound region with number 0
930 let closure_def_id = cx.tcx.hir.local_def_id(closure_expr_id);
931 let region = ty::ReFree(ty::FreeRegion {
932 scope: closure_def_id,
933 bound_region: ty::BoundRegion::BrAnon(0),
935 let region = cx.tcx.mk_region(region);
937 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.sty {
938 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
939 ty::ClosureKind::Fn => {
940 let ref_closure_ty = cx.tcx.mk_ref(region,
943 mutbl: hir::MutImmutable,
947 temp_lifetime: temp_lifetime,
949 kind: ExprKind::Deref {
954 kind: ExprKind::SelfRef,
960 ty::ClosureKind::FnMut => {
961 let ref_closure_ty = cx.tcx.mk_ref(region,
964 mutbl: hir::MutMutable,
970 kind: ExprKind::Deref {
975 kind: ExprKind::SelfRef,
980 ty::ClosureKind::FnOnce => {
985 kind: ExprKind::SelfRef,
994 kind: ExprKind::SelfRef,
998 // at this point we have `self.n`, which loads up the upvar
999 let field_kind = ExprKind::Field {
1000 lhs: self_expr.to_ref(),
1001 name: Field::new(index),
1004 // ...but the upvar might be an `&T` or `&mut T` capture, at which
1005 // point we need an implicit deref
1006 let upvar_id = ty::UpvarId {
1008 closure_expr_id: LocalDefId::from_def_id(closure_def_id),
1010 match cx.tables().upvar_capture(upvar_id) {
1011 ty::UpvarCapture::ByValue => field_kind,
1012 ty::UpvarCapture::ByRef(borrow) => {
1016 ty: cx.tcx.mk_ref(borrow.region,
1019 mutbl: borrow.kind.to_mutbl_lossy(),
1029 _ => span_bug!(expr.span, "type of & not region"),
1034 fn bin_op(op: hir::BinOpKind) -> BinOp {
1036 hir::BinOpKind::Add => BinOp::Add,
1037 hir::BinOpKind::Sub => BinOp::Sub,
1038 hir::BinOpKind::Mul => BinOp::Mul,
1039 hir::BinOpKind::Div => BinOp::Div,
1040 hir::BinOpKind::Rem => BinOp::Rem,
1041 hir::BinOpKind::BitXor => BinOp::BitXor,
1042 hir::BinOpKind::BitAnd => BinOp::BitAnd,
1043 hir::BinOpKind::BitOr => BinOp::BitOr,
1044 hir::BinOpKind::Shl => BinOp::Shl,
1045 hir::BinOpKind::Shr => BinOp::Shr,
1046 hir::BinOpKind::Eq => BinOp::Eq,
1047 hir::BinOpKind::Lt => BinOp::Lt,
1048 hir::BinOpKind::Le => BinOp::Le,
1049 hir::BinOpKind::Ne => BinOp::Ne,
1050 hir::BinOpKind::Ge => BinOp::Ge,
1051 hir::BinOpKind::Gt => BinOp::Gt,
1052 _ => bug!("no equivalent for ast binop {:?}", op),
1056 fn overloaded_operator<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1057 expr: &'tcx hir::Expr,
1058 args: Vec<ExprRef<'tcx>>)
1060 let fun = method_callee(cx, expr, None);
1068 fn overloaded_place<'a, 'gcx, 'tcx>(
1069 cx: &mut Cx<'a, 'gcx, 'tcx>,
1070 expr: &'tcx hir::Expr,
1072 overloaded_callee: Option<(DefId, &'tcx Substs<'tcx>)>,
1073 args: Vec<ExprRef<'tcx>>,
1074 ) -> ExprKind<'tcx> {
1075 // For an overloaded *x or x[y] expression of type T, the method
1076 // call returns an &T and we must add the deref so that the types
1077 // line up (this is because `*x` and `x[y]` represent places):
1079 let recv_ty = match args[0] {
1080 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
1081 ExprRef::Mirror(ref e) => e.ty
1084 // Reconstruct the output assuming it's a reference with the
1085 // same region and mutability as the receiver. This holds for
1086 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
1087 let (region, mutbl) = match recv_ty.sty {
1088 ty::Ref(region, _, mutbl) => (region, mutbl),
1089 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
1091 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut {
1096 // construct the complete expression `foo()` for the overloaded call,
1097 // which will yield the &T type
1098 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
1099 let fun = method_callee(cx, expr, overloaded_callee);
1100 let ref_expr = Expr {
1104 kind: ExprKind::Call {
1111 // construct and return a deref wrapper `*foo()`
1112 ExprKind::Deref { arg: ref_expr.to_ref() }
1115 fn capture_freevar<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1116 closure_expr: &'tcx hir::Expr,
1117 freevar: &hir::Freevar,
1118 freevar_ty: Ty<'tcx>)
1120 let var_hir_id = cx.tcx.hir.node_to_hir_id(freevar.var_id());
1121 let upvar_id = ty::UpvarId {
1123 closure_expr_id: cx.tcx.hir.local_def_id(closure_expr.id).to_local(),
1125 let upvar_capture = cx.tables().upvar_capture(upvar_id);
1126 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1127 let var_ty = cx.tables().node_id_to_type(var_hir_id);
1128 let captured_var = Expr {
1131 span: closure_expr.span,
1132 kind: convert_var(cx, closure_expr, freevar.def),
1134 match upvar_capture {
1135 ty::UpvarCapture::ByValue => captured_var.to_ref(),
1136 ty::UpvarCapture::ByRef(upvar_borrow) => {
1137 let borrow_kind = match upvar_borrow.kind {
1138 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1139 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1140 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false }
1145 span: closure_expr.span,
1146 kind: ExprKind::Borrow {
1147 region: upvar_borrow.region,
1149 arg: captured_var.to_ref(),
1156 /// Converts a list of named fields (i.e. for struct-like struct/enum ADTs) into FieldExprRef.
1157 fn field_refs<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1158 fields: &'tcx [hir::Field])
1159 -> Vec<FieldExprRef<'tcx>> {
1163 name: Field::new(cx.tcx.field_index(field.id, cx.tables)),
1164 expr: field.expr.to_ref(),