2 use crate::hair::cx::Cx;
3 use crate::hair::cx::block;
4 use crate::hair::cx::to_ref::ToRef;
5 use crate::hair::util::UserAnnotatedTyHelpers;
6 use rustc_data_structures::indexed_vec::Idx;
7 use rustc::hir::def::{CtorOf, Res, DefKind, CtorKind};
8 use rustc::mir::interpret::{GlobalId, ErrorHandled, ConstValue};
9 use rustc::ty::{self, AdtKind, Ty};
10 use rustc::ty::adjustment::{Adjustment, Adjust, AutoBorrow, AutoBorrowMutability, PointerCast};
11 use rustc::ty::subst::{InternalSubsts, SubstsRef};
13 use rustc::hir::def_id::LocalDefId;
14 use rustc::mir::BorrowKind;
17 impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
18 type Output = Expr<'tcx>;
20 fn make_mirror(self, cx: &mut Cx<'_, 'tcx>) -> Expr<'tcx> {
21 let temp_lifetime = cx.region_scope_tree.temporary_scope(self.hir_id.local_id);
22 let expr_scope = region::Scope {
23 id: self.hir_id.local_id,
24 data: region::ScopeData::Node
27 debug!("Expr::make_mirror(): id={}, span={:?}", self.hir_id, self.span);
29 let mut expr = make_mirror_unadjusted(cx, self);
31 // Now apply adjustments, if any.
32 for adjustment in cx.tables().expr_adjustments(self) {
33 debug!("make_mirror: expr={:?} applying adjustment={:?}",
36 expr = apply_adjustment(cx, self, expr, adjustment);
39 // Next, wrap this up in the expr's scope.
44 kind: ExprKind::Scope {
45 region_scope: expr_scope,
47 lint_level: LintLevel::Explicit(self.hir_id),
51 // Finally, create a destruction scope, if any.
52 if let Some(region_scope) =
53 cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id) {
58 kind: ExprKind::Scope {
61 lint_level: LintLevel::Inherited,
71 fn apply_adjustment<'a, 'tcx>(
72 cx: &mut Cx<'a, 'tcx>,
73 hir_expr: &'tcx hir::Expr,
75 adjustment: &Adjustment<'tcx>
77 let Expr { temp_lifetime, mut span, .. } = expr;
79 // Adjust the span from the block, to the last expression of the
80 // block. This is a better span when returning a mutable reference
81 // with too short a lifetime. The error message will use the span
82 // from the assignment to the return place, which should only point
83 // at the returned value, not the entire function body.
85 // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
87 // // ^ error message points at this expression.
89 let mut adjust_span = |expr: &mut Expr<'tcx>| {
90 if let ExprKind::Block { body } = expr.kind {
91 if let Some(ref last_expr) = body.expr {
92 span = last_expr.span;
98 let kind = match adjustment.kind {
99 Adjust::Pointer(PointerCast::Unsize) => {
100 adjust_span(&mut expr);
101 ExprKind::Pointer { cast: PointerCast::Unsize, source: expr.to_ref() }
103 Adjust::Pointer(cast) => {
104 ExprKind::Pointer { cast, source: expr.to_ref() }
106 Adjust::NeverToAny => {
107 ExprKind::NeverToAny { source: expr.to_ref() }
109 Adjust::Deref(None) => {
110 adjust_span(&mut expr);
111 ExprKind::Deref { arg: expr.to_ref() }
113 Adjust::Deref(Some(deref)) => {
114 // We don't need to do call adjust_span here since
115 // deref coercions always start with a built-in deref.
116 let call = deref.method_call(cx.tcx(), expr.ty);
120 ty: cx.tcx.mk_ref(deref.region,
126 kind: ExprKind::Borrow {
127 borrow_kind: deref.mutbl.to_borrow_kind(),
132 overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
134 Adjust::Borrow(AutoBorrow::Ref(_, m)) => {
136 borrow_kind: m.to_borrow_kind(),
140 Adjust::Borrow(AutoBorrow::RawPtr(m)) => {
141 // Convert this to a suitable `&foo` and
142 // then an unsafe coercion.
145 ty: cx.tcx.mk_ref(cx.tcx.lifetimes.re_erased,
151 kind: ExprKind::Borrow {
152 borrow_kind: m.to_borrow_kind(),
156 let cast_expr = Expr {
158 ty: adjustment.target,
160 kind: ExprKind::Cast { source: expr.to_ref() }
163 // To ensure that both implicit and explicit coercions are
164 // handled the same way, we insert an extra layer of indirection here.
165 // For explicit casts (e.g., 'foo as *const T'), the source of the 'Use'
166 // will be an ExprKind::Hair with the appropriate cast expression. Here,
167 // we make our Use source the generated Cast from the original coercion.
169 // In both cases, this outer 'Use' ensures that the inner 'Cast' is handled by
170 // as_operand, not by as_rvalue - causing the cast result to be stored in a temporary.
171 // Ordinary, this is identical to using the cast directly as an rvalue. However, if the
172 // source of the cast was previously borrowed as mutable, storing the cast in a
173 // temporary gives the source a chance to expire before the cast is used. For
174 // structs with a self-referential *mut ptr, this allows assignment to work as
177 // For example, consider the type 'struct Foo { field: *mut Foo }',
178 // The method 'fn bar(&mut self) { self.field = self }'
179 // triggers a coercion from '&mut self' to '*mut self'. In order
180 // for the assignment to be valid, the implicit borrow
181 // of 'self' involved in the coercion needs to end before the local
182 // containing the '*mut T' is assigned to 'self.field' - otherwise,
183 // we end up trying to assign to 'self.field' while we have another mutable borrow
186 // We only need to worry about this kind of thing for coercions from refs to ptrs,
187 // since they get rid of a borrow implicitly.
188 ExprKind::Use { source: cast_expr.to_ref() }
194 ty: adjustment.target,
200 fn make_mirror_unadjusted<'a, 'tcx>(
201 cx: &mut Cx<'a, 'tcx>,
202 expr: &'tcx hir::Expr,
204 let expr_ty = cx.tables().expr_ty(expr);
205 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
207 let kind = match expr.node {
208 // Here comes the interesting stuff:
209 hir::ExprKind::MethodCall(_, method_span, ref args) => {
210 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
211 let expr = method_callee(cx, expr, method_span,None);
212 let args = args.iter()
223 hir::ExprKind::Call(ref fun, ref args) => {
224 if cx.tables().is_method_call(expr) {
225 // The callee is something implementing Fn, FnMut, or FnOnce.
226 // Find the actual method implementation being called and
227 // build the appropriate UFCS call expression with the
228 // callee-object as expr parameter.
230 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
232 let method = method_callee(cx, expr, fun.span,None);
234 let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
235 let tupled_args = Expr {
236 ty: cx.tcx.mk_tup(arg_tys),
239 kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
244 fun: method.to_ref(),
245 args: vec![fun.to_ref(), tupled_args.to_ref()],
249 let adt_data = if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) =
252 // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
253 expr_ty.ty_adt_def().and_then(|adt_def| {
255 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) =>
256 Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id))),
257 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
264 if let Some((adt_def, index)) = adt_data {
265 let substs = cx.tables().node_substs(fun.hir_id);
266 let user_provided_types = cx.tables().user_provided_types();
267 let user_ty = user_provided_types.get(fun.hir_id)
270 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
275 debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
277 let field_refs = args.iter()
281 name: Field::new(idx),
289 variant_index: index,
296 ty: cx.tables().node_type(fun.hir_id),
305 hir::ExprKind::AddrOf(mutbl, ref expr) => {
307 borrow_kind: mutbl.to_borrow_kind(),
312 hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
314 hir::ExprKind::Assign(ref lhs, ref rhs) => {
321 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
322 if cx.tables().is_method_call(expr) {
323 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
333 hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
334 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
338 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
339 if cx.tables().is_method_call(expr) {
340 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
343 match (op.node, cx.constness) {
344 // FIXME(eddyb) use logical ops in constants when
345 // they can handle that kind of control-flow.
346 (hir::BinOpKind::And, hir::Constness::Const) => {
347 cx.control_flow_destroyed.push((
349 "`&&` operator".into(),
357 (hir::BinOpKind::Or, hir::Constness::Const) => {
358 cx.control_flow_destroyed.push((
360 "`||` operator".into(),
369 (hir::BinOpKind::And, hir::Constness::NotConst) => {
370 ExprKind::LogicalOp {
376 (hir::BinOpKind::Or, hir::Constness::NotConst) => {
377 ExprKind::LogicalOp {
385 let op = bin_op(op.node);
396 hir::ExprKind::Index(ref lhs, ref index) => {
397 if cx.tables().is_method_call(expr) {
398 overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
402 index: index.to_ref(),
407 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
408 if cx.tables().is_method_call(expr) {
409 overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
411 ExprKind::Deref { arg: arg.to_ref() }
415 hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
416 if cx.tables().is_method_call(expr) {
417 overloaded_operator(cx, expr, vec![arg.to_ref()])
426 hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
427 if cx.tables().is_method_call(expr) {
428 overloaded_operator(cx, expr, vec![arg.to_ref()])
430 if let hir::ExprKind::Lit(ref lit) = arg.node {
432 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
444 hir::ExprKind::Struct(ref qpath, ref fields, ref base) => {
446 ty::Adt(adt, substs) => {
447 match adt.adt_kind() {
448 AdtKind::Struct | AdtKind::Union => {
449 let user_provided_types = cx.tables().user_provided_types();
450 let user_ty = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
451 debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
454 variant_index: VariantIdx::new(0),
457 fields: field_refs(cx, fields),
458 base: base.as_ref().map(|base| {
461 field_types: cx.tables()
462 .fru_field_types()[expr.hir_id]
469 let res = cx.tables().qpath_res(qpath, expr.hir_id);
471 Res::Def(DefKind::Variant, variant_id) => {
472 assert!(base.is_none());
474 let index = adt.variant_index_with_id(variant_id);
475 let user_provided_types = cx.tables().user_provided_types();
476 let user_ty = user_provided_types.get(expr.hir_id)
479 "make_mirror_unadjusted: (variant) user_ty={:?}",
484 variant_index: index,
487 fields: field_refs(cx, fields),
492 span_bug!(expr.span, "unexpected res: {:?}", res);
500 "unexpected type for struct literal: {:?}",
506 hir::ExprKind::Closure(..) => {
507 let closure_ty = cx.tables().expr_ty(expr);
508 let (def_id, substs, movability) = match closure_ty.sty {
509 ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
510 ty::Generator(def_id, substs, movability) => {
511 (def_id, UpvarSubsts::Generator(substs), Some(movability))
514 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
517 let upvars = cx.tcx.upvars(def_id).iter()
518 .flat_map(|upvars| upvars.iter())
519 .zip(substs.upvar_tys(def_id, cx.tcx))
520 .map(|((&var_hir_id, _), ty)| capture_upvar(cx, expr, var_hir_id, ty))
530 hir::ExprKind::Path(ref qpath) => {
531 let res = cx.tables().qpath_res(qpath, expr.hir_id);
532 convert_path_expr(cx, expr, res)
535 hir::ExprKind::InlineAsm(ref asm, ref outputs, ref inputs) => {
536 ExprKind::InlineAsm {
538 outputs: outputs.to_ref(),
539 inputs: inputs.to_ref(),
543 // Now comes the rote stuff:
544 hir::ExprKind::Repeat(ref v, ref count) => {
545 let def_id = cx.tcx.hir().local_def_id(count.hir_id);
546 let substs = InternalSubsts::identity_for_item(cx.tcx.global_tcx(), def_id);
547 let instance = ty::Instance::resolve(
553 let global_id = GlobalId {
557 let span = cx.tcx.def_span(def_id);
558 let count = match cx.tcx.at(span).const_eval(cx.param_env.and(global_id)) {
559 Ok(cv) => cv.unwrap_usize(cx.tcx),
560 Err(ErrorHandled::Reported) => 0,
561 Err(ErrorHandled::TooGeneric) => {
562 cx.tcx.sess.span_err(span, "array lengths can't depend on generic parameters");
572 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
573 hir::ExprKind::Break(dest, ref value) => {
574 match dest.target_id {
575 Ok(target_id) => ExprKind::Break {
576 label: region::Scope {
577 id: target_id.local_id,
578 data: region::ScopeData::Node
580 value: value.to_ref(),
582 Err(err) => bug!("invalid loop id for break: {}", err)
585 hir::ExprKind::Continue(dest) => {
586 match dest.target_id {
587 Ok(loop_id) => ExprKind::Continue {
588 label: region::Scope {
589 id: loop_id.local_id,
590 data: region::ScopeData::Node
593 Err(err) => bug!("invalid loop id for continue: {}", err)
596 hir::ExprKind::Match(ref discr, ref arms, _) => {
598 scrutinee: discr.to_ref(),
599 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
602 hir::ExprKind::Loop(ref body, _, _) => {
604 body: block::to_expr_ref(cx, body),
607 hir::ExprKind::Field(ref source, ..) => {
609 lhs: source.to_ref(),
610 name: Field::new(cx.tcx.field_index(expr.hir_id, cx.tables)),
613 hir::ExprKind::Cast(ref source, ref cast_ty) => {
614 // Check for a user-given type annotation on this `cast`
615 let user_provided_types = cx.tables.user_provided_types();
616 let user_ty = user_provided_types.get(cast_ty.hir_id);
619 "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
625 // Check to see if this cast is a "coercion cast", where the cast is actually done
626 // using a coercion (or is a no-op).
627 let cast = if cx.tables().is_coercion_cast(source.hir_id) {
628 // Convert the lexpr to a vexpr.
629 ExprKind::Use { source: source.to_ref() }
631 // check whether this is casting an enum variant discriminant
632 // to prevent cycles, we refer to the discriminant initializer
633 // which is always an integer and thus doesn't need to know the
634 // enum's layout (or its tag type) to compute it during const eval
638 // B = A as isize + 4,
640 // The correct solution would be to add symbolic computations to miri,
641 // so we wouldn't have to compute and store the actual value
642 let var = if let hir::ExprKind::Path(ref qpath) = source.node {
643 let res = cx.tables().qpath_res(qpath, source.hir_id);
646 .node_type(source.hir_id)
648 .and_then(|adt_def| {
651 DefKind::Ctor(CtorOf::Variant, CtorKind::Const),
654 let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
655 let (d, o) = adt_def.discriminant_def_for_variant(idx);
656 use rustc::ty::util::IntTypeExt;
657 let ty = adt_def.repr.discr_type();
658 let ty = ty.to_ty(cx.tcx());
668 let source = if let Some((did, offset, var_ty)) = var {
669 let mk_const = |literal| Expr {
673 kind: ExprKind::Literal {
678 let offset = mk_const(ty::Const::from_bits(
681 cx.param_env.and(var_ty),
685 // in case we are offsetting from a computed discriminant
686 // and not the beginning of discriminants (which is always `0`)
687 let substs = InternalSubsts::identity_for_item(cx.tcx(), did);
688 let lhs = mk_const(cx.tcx().mk_const(ty::Const {
689 val: ConstValue::Unevaluated(did, substs),
692 let bin = ExprKind::Binary {
710 ExprKind::Cast { source }
713 if let Some(user_ty) = user_ty {
714 // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
715 // inefficient, revisit this when performance becomes an issue.
716 let cast_expr = Expr {
722 debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
724 ExprKind::ValueTypeAscription {
725 source: cast_expr.to_ref(),
726 user_ty: Some(*user_ty),
732 hir::ExprKind::Type(ref source, ref ty) => {
733 let user_provided_types = cx.tables.user_provided_types();
734 let user_ty = user_provided_types.get(ty.hir_id).map(|u_ty| *u_ty);
735 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
736 if source.is_place_expr() {
737 ExprKind::PlaceTypeAscription {
738 source: source.to_ref(),
742 ExprKind::ValueTypeAscription {
743 source: source.to_ref(),
748 hir::ExprKind::DropTemps(ref source) => {
749 ExprKind::Use { source: source.to_ref() }
751 hir::ExprKind::Box(ref value) => {
753 value: value.to_ref(),
756 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
757 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
759 hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: v.to_ref() },
760 hir::ExprKind::Err => unreachable!(),
771 fn user_substs_applied_to_res(
772 cx: &mut Cx<'a, 'tcx>,
775 ) -> Option<ty::CanonicalUserType<'tcx>> {
776 debug!("user_substs_applied_to_res: res={:?}", res);
777 let user_provided_type = match res {
778 // A reference to something callable -- e.g., a fn, method, or
779 // a tuple-struct or tuple-variant. This has the type of a
780 // `Fn` but with the user-given substitutions.
781 Res::Def(DefKind::Fn, _) |
782 Res::Def(DefKind::Method, _) |
783 Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
784 Res::Def(DefKind::Const, _) |
785 Res::Def(DefKind::AssocConst, _) =>
786 cx.tables().user_provided_types().get(hir_id).map(|u_ty| *u_ty),
788 // A unit struct/variant which is used as a value (e.g.,
789 // `None`). This has the type of the enum/struct that defines
790 // this variant -- but with the substitutions given by the
792 Res::Def(DefKind::Ctor(_, CtorKind::Const), _) =>
793 cx.user_substs_applied_to_ty_of_hir_id(hir_id),
795 // `Self` is used in expression as a tuple struct constructor or an unit struct constructor
797 cx.user_substs_applied_to_ty_of_hir_id(hir_id),
800 bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id)
802 debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
806 fn method_callee<'a, 'tcx>(
807 cx: &mut Cx<'a, 'tcx>,
810 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
812 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
813 let (def_id, substs, user_ty) = match overloaded_callee {
814 Some((def_id, substs)) => (def_id, substs, None),
816 let (kind, def_id) = cx.tables().type_dependent_def(expr.hir_id)
818 span_bug!(expr.span, "no type-dependent def for method callee")
820 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, Res::Def(kind, def_id));
821 debug!("method_callee: user_ty={:?}", user_ty);
822 (def_id, cx.tables().node_substs(expr.hir_id), user_ty)
825 let ty = cx.tcx().mk_fn_def(def_id, substs);
830 kind: ExprKind::Literal {
831 literal: ty::Const::zero_sized(cx.tcx(), ty),
837 trait ToBorrowKind { fn to_borrow_kind(&self) -> BorrowKind; }
839 impl ToBorrowKind for AutoBorrowMutability {
840 fn to_borrow_kind(&self) -> BorrowKind {
841 use rustc::ty::adjustment::AllowTwoPhase;
843 AutoBorrowMutability::Mutable { allow_two_phase_borrow } =>
844 BorrowKind::Mut { allow_two_phase_borrow: match allow_two_phase_borrow {
845 AllowTwoPhase::Yes => true,
846 AllowTwoPhase::No => false
848 AutoBorrowMutability::Immutable =>
854 impl ToBorrowKind for hir::Mutability {
855 fn to_borrow_kind(&self) -> BorrowKind {
857 hir::MutMutable => BorrowKind::Mut { allow_two_phase_borrow: false },
858 hir::MutImmutable => BorrowKind::Shared,
863 fn convert_arm<'a, 'tcx>(cx: &mut Cx<'a, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
865 patterns: arm.pats.iter().map(|p| cx.pattern_from_hir(p)).collect(),
866 guard: match arm.guard {
867 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
870 body: arm.body.to_ref(),
871 lint_level: LintLevel::Explicit(arm.hir_id),
872 scope: region::Scope {
873 id: arm.hir_id.local_id,
874 data: region::ScopeData::Node
880 fn convert_path_expr<'a, 'tcx>(
881 cx: &mut Cx<'a, 'tcx>,
882 expr: &'tcx hir::Expr,
884 ) -> ExprKind<'tcx> {
885 let substs = cx.tables().node_substs(expr.hir_id);
887 // A regular function, constructor function or a constant.
888 Res::Def(DefKind::Fn, _) |
889 Res::Def(DefKind::Method, _) |
890 Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
891 Res::SelfCtor(..) => {
892 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
893 debug!("convert_path_expr: user_ty={:?}", user_ty);
895 literal: ty::Const::zero_sized(
897 cx.tables().node_type(expr.hir_id),
903 Res::Def(DefKind::ConstParam, def_id) => {
904 let hir_id = cx.tcx.hir().as_local_hir_id(def_id).unwrap();
905 let item_id = cx.tcx.hir().get_parent_node(hir_id);
906 let item_def_id = cx.tcx.hir().local_def_id(item_id);
907 let generics = cx.tcx.generics_of(item_def_id);
908 let local_def_id = cx.tcx.hir().local_def_id(hir_id);
909 let index = generics.param_def_id_to_index[&local_def_id];
910 let name = cx.tcx.hir().name(hir_id).as_interned_str();
911 let val = ConstValue::Param(ty::ParamConst::new(index, name));
913 literal: cx.tcx.mk_const(
916 ty: cx.tables().node_type(expr.hir_id),
923 Res::Def(DefKind::Const, def_id) |
924 Res::Def(DefKind::AssocConst, def_id) => {
925 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
926 debug!("convert_path_expr: (const) user_ty={:?}", user_ty);
928 literal: cx.tcx.mk_const(ty::Const {
929 val: ConstValue::Unevaluated(def_id, substs),
930 ty: cx.tcx.type_of(def_id),
936 Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
937 let user_provided_types = cx.tables.user_provided_types();
938 let user_provided_type = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
939 debug!("convert_path_expr: user_provided_type={:?}", user_provided_type);
940 let ty = cx.tables().node_type(expr.hir_id);
942 // A unit struct/variant which is used as a value.
943 // We return a completely different ExprKind here to account for this special case.
944 ty::Adt(adt_def, substs) => {
947 variant_index: adt_def.variant_index_with_ctor_id(def_id),
949 user_ty: user_provided_type,
954 _ => bug!("unexpected ty: {:?}", ty),
958 Res::Def(DefKind::Static, id) => ExprKind::StaticRef { id },
960 Res::Local(var_hir_id) => convert_var(cx, expr, var_hir_id),
962 _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
967 cx: &mut Cx<'_, 'tcx>,
968 expr: &'tcx hir::Expr,
969 var_hir_id: hir::HirId,
970 ) -> ExprKind<'tcx> {
971 let upvar_index = cx.tables().upvar_list.get(&cx.body_owner)
972 .and_then(|upvars| upvars.get_full(&var_hir_id).map(|(i, _, _)| i));
974 debug!("convert_var({:?}): upvar_index={:?}, body_owner={:?}",
975 var_hir_id, upvar_index, cx.body_owner);
977 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
980 None => ExprKind::VarRef { id: var_hir_id },
982 Some(upvar_index) => {
983 let closure_def_id = cx.body_owner;
984 let upvar_id = ty::UpvarId {
985 var_path: ty::UpvarPath {hir_id: var_hir_id},
986 closure_expr_id: LocalDefId::from_def_id(closure_def_id),
988 let var_ty = cx.tables().node_type(var_hir_id);
990 // FIXME free regions in closures are not right
991 let closure_ty = cx.tables().node_type(
992 cx.tcx.hir().local_def_id_to_hir_id(upvar_id.closure_expr_id),
995 // FIXME we're just hard-coding the idea that the
996 // signature will be &self or &mut self and hence will
997 // have a bound region with number 0
998 let region = ty::ReFree(ty::FreeRegion {
999 scope: closure_def_id,
1000 bound_region: ty::BoundRegion::BrAnon(0),
1002 let region = cx.tcx.mk_region(region);
1004 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.sty {
1005 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
1006 ty::ClosureKind::Fn => {
1007 let ref_closure_ty = cx.tcx.mk_ref(region,
1010 mutbl: hir::MutImmutable,
1014 temp_lifetime: temp_lifetime,
1016 kind: ExprKind::Deref {
1021 kind: ExprKind::SelfRef,
1027 ty::ClosureKind::FnMut => {
1028 let ref_closure_ty = cx.tcx.mk_ref(region,
1031 mutbl: hir::MutMutable,
1037 kind: ExprKind::Deref {
1042 kind: ExprKind::SelfRef,
1047 ty::ClosureKind::FnOnce => {
1052 kind: ExprKind::SelfRef,
1061 kind: ExprKind::SelfRef,
1065 // at this point we have `self.n`, which loads up the upvar
1066 let field_kind = ExprKind::Field {
1067 lhs: self_expr.to_ref(),
1068 name: Field::new(upvar_index),
1071 // ...but the upvar might be an `&T` or `&mut T` capture, at which
1072 // point we need an implicit deref
1073 match cx.tables().upvar_capture(upvar_id) {
1074 ty::UpvarCapture::ByValue => field_kind,
1075 ty::UpvarCapture::ByRef(borrow) => {
1079 ty: cx.tcx.mk_ref(borrow.region,
1082 mutbl: borrow.kind.to_mutbl_lossy(),
1095 fn bin_op(op: hir::BinOpKind) -> BinOp {
1097 hir::BinOpKind::Add => BinOp::Add,
1098 hir::BinOpKind::Sub => BinOp::Sub,
1099 hir::BinOpKind::Mul => BinOp::Mul,
1100 hir::BinOpKind::Div => BinOp::Div,
1101 hir::BinOpKind::Rem => BinOp::Rem,
1102 hir::BinOpKind::BitXor => BinOp::BitXor,
1103 hir::BinOpKind::BitAnd => BinOp::BitAnd,
1104 hir::BinOpKind::BitOr => BinOp::BitOr,
1105 hir::BinOpKind::Shl => BinOp::Shl,
1106 hir::BinOpKind::Shr => BinOp::Shr,
1107 hir::BinOpKind::Eq => BinOp::Eq,
1108 hir::BinOpKind::Lt => BinOp::Lt,
1109 hir::BinOpKind::Le => BinOp::Le,
1110 hir::BinOpKind::Ne => BinOp::Ne,
1111 hir::BinOpKind::Ge => BinOp::Ge,
1112 hir::BinOpKind::Gt => BinOp::Gt,
1113 _ => bug!("no equivalent for ast binop {:?}", op),
1117 fn overloaded_operator<'a, 'tcx>(
1118 cx: &mut Cx<'a, 'tcx>,
1119 expr: &'tcx hir::Expr,
1120 args: Vec<ExprRef<'tcx>>
1121 ) -> ExprKind<'tcx> {
1122 let fun = method_callee(cx, expr, expr.span, None);
1127 from_hir_call: false,
1131 fn overloaded_place<'a, 'tcx>(
1132 cx: &mut Cx<'a, 'tcx>,
1133 expr: &'tcx hir::Expr,
1135 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
1136 args: Vec<ExprRef<'tcx>>,
1137 ) -> ExprKind<'tcx> {
1138 // For an overloaded *x or x[y] expression of type T, the method
1139 // call returns an &T and we must add the deref so that the types
1140 // line up (this is because `*x` and `x[y]` represent places):
1142 let recv_ty = match args[0] {
1143 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
1144 ExprRef::Mirror(ref e) => e.ty
1147 // Reconstruct the output assuming it's a reference with the
1148 // same region and mutability as the receiver. This holds for
1149 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
1150 let (region, mutbl) = match recv_ty.sty {
1151 ty::Ref(region, _, mutbl) => (region, mutbl),
1152 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
1154 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut {
1159 // construct the complete expression `foo()` for the overloaded call,
1160 // which will yield the &T type
1161 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
1162 let fun = method_callee(cx, expr, expr.span, overloaded_callee);
1163 let ref_expr = Expr {
1167 kind: ExprKind::Call {
1171 from_hir_call: false,
1175 // construct and return a deref wrapper `*foo()`
1176 ExprKind::Deref { arg: ref_expr.to_ref() }
1179 fn capture_upvar<'tcx>(
1180 cx: &mut Cx<'_, 'tcx>,
1181 closure_expr: &'tcx hir::Expr,
1182 var_hir_id: hir::HirId,
1184 ) -> ExprRef<'tcx> {
1185 let upvar_id = ty::UpvarId {
1186 var_path: ty::UpvarPath { hir_id: var_hir_id },
1187 closure_expr_id: cx.tcx.hir().local_def_id(closure_expr.hir_id).to_local(),
1189 let upvar_capture = cx.tables().upvar_capture(upvar_id);
1190 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1191 let var_ty = cx.tables().node_type(var_hir_id);
1192 let captured_var = Expr {
1195 span: closure_expr.span,
1196 kind: convert_var(cx, closure_expr, var_hir_id),
1198 match upvar_capture {
1199 ty::UpvarCapture::ByValue => captured_var.to_ref(),
1200 ty::UpvarCapture::ByRef(upvar_borrow) => {
1201 let borrow_kind = match upvar_borrow.kind {
1202 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1203 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1204 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false }
1209 span: closure_expr.span,
1210 kind: ExprKind::Borrow {
1212 arg: captured_var.to_ref(),
1219 /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExprRef.
1220 fn field_refs<'a, 'tcx>(
1221 cx: &mut Cx<'a, 'tcx>,
1222 fields: &'tcx [hir::Field]
1223 ) -> Vec<FieldExprRef<'tcx>> {
1227 name: Field::new(cx.tcx.field_index(field.hir_id, cx.tables)),
1228 expr: field.expr.to_ref(),