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_index::vec::Idx;
7 use rustc::hir::def::{CtorOf, Res, DefKind, CtorKind};
8 use rustc::mir::interpret::{GlobalId, ErrorHandled};
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.kind {
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.kind {
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.kind {
509 ty::Closure(def_id, substs) => (def_id,
510 UpvarSubsts::Closure(substs), None),
511 ty::Generator(def_id, substs, movability) => {
512 (def_id, UpvarSubsts::Generator(substs), Some(movability))
515 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
518 let upvars = cx.tcx.upvars(def_id).iter()
519 .flat_map(|upvars| upvars.iter())
520 .zip(substs.upvar_tys(def_id, cx.tcx))
521 .map(|((&var_hir_id, _), ty)| capture_upvar(cx, expr, var_hir_id, ty))
531 hir::ExprKind::Path(ref qpath) => {
532 let res = cx.tables().qpath_res(qpath, expr.hir_id);
533 convert_path_expr(cx, expr, res)
536 hir::ExprKind::InlineAsm(ref asm, ref outputs, ref inputs) => {
537 ExprKind::InlineAsm {
539 outputs: outputs.to_ref(),
540 inputs: inputs.to_ref(),
544 // Now comes the rote stuff:
545 hir::ExprKind::Repeat(ref v, ref count) => {
546 let def_id = cx.tcx.hir().local_def_id(count.hir_id);
547 let substs = InternalSubsts::identity_for_item(cx.tcx, def_id);
548 let instance = ty::Instance::resolve(
554 let global_id = GlobalId {
558 let span = cx.tcx.def_span(def_id);
559 let count = match cx.tcx.at(span).const_eval(cx.param_env.and(global_id)) {
560 Ok(cv) => cv.eval_usize(cx.tcx, cx.param_env),
561 Err(ErrorHandled::Reported) => 0,
562 Err(ErrorHandled::TooGeneric) => {
563 cx.tcx.sess.span_err(span, "array lengths can't depend on generic parameters");
573 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
574 hir::ExprKind::Break(dest, ref value) => {
575 match dest.target_id {
576 Ok(target_id) => ExprKind::Break {
577 label: region::Scope {
578 id: target_id.local_id,
579 data: region::ScopeData::Node
581 value: value.to_ref(),
583 Err(err) => bug!("invalid loop id for break: {}", err)
586 hir::ExprKind::Continue(dest) => {
587 match dest.target_id {
588 Ok(loop_id) => ExprKind::Continue {
589 label: region::Scope {
590 id: loop_id.local_id,
591 data: region::ScopeData::Node
594 Err(err) => bug!("invalid loop id for continue: {}", err)
597 hir::ExprKind::Match(ref discr, ref arms, _) => {
599 scrutinee: discr.to_ref(),
600 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
603 hir::ExprKind::Loop(ref body, _, _) => {
605 body: block::to_expr_ref(cx, body),
608 hir::ExprKind::Field(ref source, ..) => {
610 lhs: source.to_ref(),
611 name: Field::new(cx.tcx.field_index(expr.hir_id, cx.tables)),
614 hir::ExprKind::Cast(ref source, ref cast_ty) => {
615 // Check for a user-given type annotation on this `cast`
616 let user_provided_types = cx.tables.user_provided_types();
617 let user_ty = user_provided_types.get(cast_ty.hir_id);
620 "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
626 // Check to see if this cast is a "coercion cast", where the cast is actually done
627 // using a coercion (or is a no-op).
628 let cast = if cx.tables().is_coercion_cast(source.hir_id) {
629 // Convert the lexpr to a vexpr.
630 ExprKind::Use { source: source.to_ref() }
631 } else if cx.tables().expr_ty(source).is_region_ptr() {
632 // Special cased so that we can type check that the element
633 // type of the source matches the pointed to type of the
635 ExprKind::Pointer { source: source.to_ref(), cast: PointerCast::ArrayToPointer }
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.kind {
649 let res = cx.tables().qpath_res(qpath, source.hir_id);
652 .node_type(source.hir_id)
654 .and_then(|adt_def| {
657 DefKind::Ctor(CtorOf::Variant, CtorKind::Const),
660 let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
661 let (d, o) = adt_def.discriminant_def_for_variant(idx);
662 use rustc::ty::util::IntTypeExt;
663 let ty = adt_def.repr.discr_type();
664 let ty = ty.to_ty(cx.tcx());
674 let source = if let Some((did, offset, var_ty)) = var {
675 let mk_const = |literal| Expr {
679 kind: ExprKind::Literal {
684 let offset = mk_const(ty::Const::from_bits(
687 cx.param_env.and(var_ty),
691 // in case we are offsetting from a computed discriminant
692 // and not the beginning of discriminants (which is always `0`)
693 let substs = InternalSubsts::identity_for_item(cx.tcx(), did);
694 let lhs = mk_const(cx.tcx().mk_const(ty::Const {
695 val: ty::ConstKind::Unevaluated(did, substs),
698 let bin = ExprKind::Binary {
716 ExprKind::Cast { source }
719 if let Some(user_ty) = user_ty {
720 // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
721 // inefficient, revisit this when performance becomes an issue.
722 let cast_expr = Expr {
728 debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
730 ExprKind::ValueTypeAscription {
731 source: cast_expr.to_ref(),
732 user_ty: Some(*user_ty),
738 hir::ExprKind::Type(ref source, ref ty) => {
739 let user_provided_types = cx.tables.user_provided_types();
740 let user_ty = user_provided_types.get(ty.hir_id).map(|u_ty| *u_ty);
741 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
742 if source.is_place_expr() {
743 ExprKind::PlaceTypeAscription {
744 source: source.to_ref(),
748 ExprKind::ValueTypeAscription {
749 source: source.to_ref(),
754 hir::ExprKind::DropTemps(ref source) => {
755 ExprKind::Use { source: source.to_ref() }
757 hir::ExprKind::Box(ref value) => {
759 value: value.to_ref(),
762 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
763 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
765 hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: v.to_ref() },
766 hir::ExprKind::Err => unreachable!(),
777 fn user_substs_applied_to_res(
778 cx: &mut Cx<'a, 'tcx>,
781 ) -> Option<ty::CanonicalUserType<'tcx>> {
782 debug!("user_substs_applied_to_res: res={:?}", res);
783 let user_provided_type = match res {
784 // A reference to something callable -- e.g., a fn, method, or
785 // a tuple-struct or tuple-variant. This has the type of a
786 // `Fn` but with the user-given substitutions.
787 Res::Def(DefKind::Fn, _) |
788 Res::Def(DefKind::Method, _) |
789 Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
790 Res::Def(DefKind::Const, _) |
791 Res::Def(DefKind::AssocConst, _) =>
792 cx.tables().user_provided_types().get(hir_id).map(|u_ty| *u_ty),
794 // A unit struct/variant which is used as a value (e.g.,
795 // `None`). This has the type of the enum/struct that defines
796 // this variant -- but with the substitutions given by the
798 Res::Def(DefKind::Ctor(_, CtorKind::Const), _) =>
799 cx.user_substs_applied_to_ty_of_hir_id(hir_id),
801 // `Self` is used in expression as a tuple struct constructor or an unit struct constructor
803 cx.user_substs_applied_to_ty_of_hir_id(hir_id),
806 bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id)
808 debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
812 fn method_callee<'a, 'tcx>(
813 cx: &mut Cx<'a, 'tcx>,
816 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
818 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
819 let (def_id, substs, user_ty) = match overloaded_callee {
820 Some((def_id, substs)) => (def_id, substs, None),
822 let (kind, def_id) = cx.tables().type_dependent_def(expr.hir_id)
824 span_bug!(expr.span, "no type-dependent def for method callee")
826 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, Res::Def(kind, def_id));
827 debug!("method_callee: user_ty={:?}", user_ty);
828 (def_id, cx.tables().node_substs(expr.hir_id), user_ty)
831 let ty = cx.tcx().mk_fn_def(def_id, substs);
836 kind: ExprKind::Literal {
837 literal: ty::Const::zero_sized(cx.tcx(), ty),
843 trait ToBorrowKind { fn to_borrow_kind(&self) -> BorrowKind; }
845 impl ToBorrowKind for AutoBorrowMutability {
846 fn to_borrow_kind(&self) -> BorrowKind {
847 use rustc::ty::adjustment::AllowTwoPhase;
849 AutoBorrowMutability::Mutable { allow_two_phase_borrow } =>
850 BorrowKind::Mut { allow_two_phase_borrow: match allow_two_phase_borrow {
851 AllowTwoPhase::Yes => true,
852 AllowTwoPhase::No => false
854 AutoBorrowMutability::Immutable =>
860 impl ToBorrowKind for hir::Mutability {
861 fn to_borrow_kind(&self) -> BorrowKind {
863 hir::Mutability::Mutable => BorrowKind::Mut { allow_two_phase_borrow: false },
864 hir::Mutability::Immutable => BorrowKind::Shared,
869 fn convert_arm<'tcx>(cx: &mut Cx<'_, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
871 pattern: cx.pattern_from_hir(&arm.pat),
872 guard: match arm.guard {
873 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
876 body: arm.body.to_ref(),
877 lint_level: LintLevel::Explicit(arm.hir_id),
878 scope: region::Scope {
879 id: arm.hir_id.local_id,
880 data: region::ScopeData::Node
886 fn convert_path_expr<'a, 'tcx>(
887 cx: &mut Cx<'a, 'tcx>,
888 expr: &'tcx hir::Expr,
890 ) -> ExprKind<'tcx> {
891 let substs = cx.tables().node_substs(expr.hir_id);
893 // A regular function, constructor function or a constant.
894 Res::Def(DefKind::Fn, _) |
895 Res::Def(DefKind::Method, _) |
896 Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
897 Res::SelfCtor(..) => {
898 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
899 debug!("convert_path_expr: user_ty={:?}", user_ty);
901 literal: ty::Const::zero_sized(
903 cx.tables().node_type(expr.hir_id),
909 Res::Def(DefKind::ConstParam, def_id) => {
910 let hir_id = cx.tcx.hir().as_local_hir_id(def_id).unwrap();
911 let item_id = cx.tcx.hir().get_parent_node(hir_id);
912 let item_def_id = cx.tcx.hir().local_def_id(item_id);
913 let generics = cx.tcx.generics_of(item_def_id);
914 let local_def_id = cx.tcx.hir().local_def_id(hir_id);
915 let index = generics.param_def_id_to_index[&local_def_id];
916 let name = cx.tcx.hir().name(hir_id);
917 let val = ty::ConstKind::Param(ty::ParamConst::new(index, name));
919 literal: cx.tcx.mk_const(
922 ty: cx.tables().node_type(expr.hir_id),
929 Res::Def(DefKind::Const, def_id) |
930 Res::Def(DefKind::AssocConst, def_id) => {
931 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
932 debug!("convert_path_expr: (const) user_ty={:?}", user_ty);
934 literal: cx.tcx.mk_const(ty::Const {
935 val: ty::ConstKind::Unevaluated(def_id, substs),
936 ty: cx.tables().node_type(expr.hir_id),
942 Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
943 let user_provided_types = cx.tables.user_provided_types();
944 let user_provided_type = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
945 debug!("convert_path_expr: user_provided_type={:?}", user_provided_type);
946 let ty = cx.tables().node_type(expr.hir_id);
948 // A unit struct/variant which is used as a value.
949 // We return a completely different ExprKind here to account for this special case.
950 ty::Adt(adt_def, substs) => {
953 variant_index: adt_def.variant_index_with_ctor_id(def_id),
955 user_ty: user_provided_type,
960 _ => bug!("unexpected ty: {:?}", ty),
964 Res::Def(DefKind::Static, id) => ExprKind::StaticRef { id },
966 Res::Local(var_hir_id) => convert_var(cx, expr, var_hir_id),
968 _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
973 cx: &mut Cx<'_, 'tcx>,
974 expr: &'tcx hir::Expr,
975 var_hir_id: hir::HirId,
976 ) -> ExprKind<'tcx> {
977 let upvar_index = cx.tables().upvar_list.get(&cx.body_owner)
978 .and_then(|upvars| upvars.get_full(&var_hir_id).map(|(i, _, _)| i));
980 debug!("convert_var({:?}): upvar_index={:?}, body_owner={:?}",
981 var_hir_id, upvar_index, cx.body_owner);
983 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
986 None => ExprKind::VarRef { id: var_hir_id },
988 Some(upvar_index) => {
989 let closure_def_id = cx.body_owner;
990 let upvar_id = ty::UpvarId {
991 var_path: ty::UpvarPath {hir_id: var_hir_id},
992 closure_expr_id: LocalDefId::from_def_id(closure_def_id),
994 let var_ty = cx.tables().node_type(var_hir_id);
996 // FIXME free regions in closures are not right
997 let closure_ty = cx.tables().node_type(
998 cx.tcx.hir().local_def_id_to_hir_id(upvar_id.closure_expr_id),
1001 // FIXME we're just hard-coding the idea that the
1002 // signature will be &self or &mut self and hence will
1003 // have a bound region with number 0
1004 let region = ty::ReFree(ty::FreeRegion {
1005 scope: closure_def_id,
1006 bound_region: ty::BoundRegion::BrAnon(0),
1008 let region = cx.tcx.mk_region(region);
1010 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.kind {
1011 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
1012 ty::ClosureKind::Fn => {
1013 let ref_closure_ty = cx.tcx.mk_ref(region,
1016 mutbl: hir::Mutability::Immutable,
1022 kind: ExprKind::Deref {
1027 kind: ExprKind::SelfRef,
1033 ty::ClosureKind::FnMut => {
1034 let ref_closure_ty = cx.tcx.mk_ref(region,
1037 mutbl: hir::Mutability::Mutable,
1043 kind: ExprKind::Deref {
1048 kind: ExprKind::SelfRef,
1053 ty::ClosureKind::FnOnce => {
1058 kind: ExprKind::SelfRef,
1067 kind: ExprKind::SelfRef,
1071 // at this point we have `self.n`, which loads up the upvar
1072 let field_kind = ExprKind::Field {
1073 lhs: self_expr.to_ref(),
1074 name: Field::new(upvar_index),
1077 // ...but the upvar might be an `&T` or `&mut T` capture, at which
1078 // point we need an implicit deref
1079 match cx.tables().upvar_capture(upvar_id) {
1080 ty::UpvarCapture::ByValue => field_kind,
1081 ty::UpvarCapture::ByRef(borrow) => {
1085 ty: cx.tcx.mk_ref(borrow.region,
1088 mutbl: borrow.kind.to_mutbl_lossy(),
1101 fn bin_op(op: hir::BinOpKind) -> BinOp {
1103 hir::BinOpKind::Add => BinOp::Add,
1104 hir::BinOpKind::Sub => BinOp::Sub,
1105 hir::BinOpKind::Mul => BinOp::Mul,
1106 hir::BinOpKind::Div => BinOp::Div,
1107 hir::BinOpKind::Rem => BinOp::Rem,
1108 hir::BinOpKind::BitXor => BinOp::BitXor,
1109 hir::BinOpKind::BitAnd => BinOp::BitAnd,
1110 hir::BinOpKind::BitOr => BinOp::BitOr,
1111 hir::BinOpKind::Shl => BinOp::Shl,
1112 hir::BinOpKind::Shr => BinOp::Shr,
1113 hir::BinOpKind::Eq => BinOp::Eq,
1114 hir::BinOpKind::Lt => BinOp::Lt,
1115 hir::BinOpKind::Le => BinOp::Le,
1116 hir::BinOpKind::Ne => BinOp::Ne,
1117 hir::BinOpKind::Ge => BinOp::Ge,
1118 hir::BinOpKind::Gt => BinOp::Gt,
1119 _ => bug!("no equivalent for ast binop {:?}", op),
1123 fn overloaded_operator<'a, 'tcx>(
1124 cx: &mut Cx<'a, 'tcx>,
1125 expr: &'tcx hir::Expr,
1126 args: Vec<ExprRef<'tcx>>
1127 ) -> ExprKind<'tcx> {
1128 let fun = method_callee(cx, expr, expr.span, None);
1133 from_hir_call: false,
1137 fn overloaded_place<'a, 'tcx>(
1138 cx: &mut Cx<'a, 'tcx>,
1139 expr: &'tcx hir::Expr,
1141 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
1142 args: Vec<ExprRef<'tcx>>,
1143 ) -> ExprKind<'tcx> {
1144 // For an overloaded *x or x[y] expression of type T, the method
1145 // call returns an &T and we must add the deref so that the types
1146 // line up (this is because `*x` and `x[y]` represent places):
1148 let recv_ty = match args[0] {
1149 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
1150 ExprRef::Mirror(ref e) => e.ty
1153 // Reconstruct the output assuming it's a reference with the
1154 // same region and mutability as the receiver. This holds for
1155 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
1156 let (region, mutbl) = match recv_ty.kind {
1157 ty::Ref(region, _, mutbl) => (region, mutbl),
1158 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
1160 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut {
1165 // construct the complete expression `foo()` for the overloaded call,
1166 // which will yield the &T type
1167 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
1168 let fun = method_callee(cx, expr, expr.span, overloaded_callee);
1169 let ref_expr = Expr {
1173 kind: ExprKind::Call {
1177 from_hir_call: false,
1181 // construct and return a deref wrapper `*foo()`
1182 ExprKind::Deref { arg: ref_expr.to_ref() }
1185 fn capture_upvar<'tcx>(
1186 cx: &mut Cx<'_, 'tcx>,
1187 closure_expr: &'tcx hir::Expr,
1188 var_hir_id: hir::HirId,
1190 ) -> ExprRef<'tcx> {
1191 let upvar_id = ty::UpvarId {
1192 var_path: ty::UpvarPath { hir_id: var_hir_id },
1193 closure_expr_id: cx.tcx.hir().local_def_id(closure_expr.hir_id).to_local(),
1195 let upvar_capture = cx.tables().upvar_capture(upvar_id);
1196 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1197 let var_ty = cx.tables().node_type(var_hir_id);
1198 let captured_var = Expr {
1201 span: closure_expr.span,
1202 kind: convert_var(cx, closure_expr, var_hir_id),
1204 match upvar_capture {
1205 ty::UpvarCapture::ByValue => captured_var.to_ref(),
1206 ty::UpvarCapture::ByRef(upvar_borrow) => {
1207 let borrow_kind = match upvar_borrow.kind {
1208 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1209 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1210 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false }
1215 span: closure_expr.span,
1216 kind: ExprKind::Borrow {
1218 arg: captured_var.to_ref(),
1225 /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExprRef.
1226 fn field_refs<'a, 'tcx>(
1227 cx: &mut Cx<'a, 'tcx>,
1228 fields: &'tcx [hir::Field]
1229 ) -> Vec<FieldExprRef<'tcx>> {
1233 name: Field::new(cx.tcx.field_index(field.hir_id, cx.tables)),
1234 expr: field.expr.to_ref(),