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};
26 impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
27 type Output = Expr<'tcx>;
29 fn make_mirror<'a, 'gcx>(self, cx: &mut Cx<'a, 'gcx, 'tcx>) -> Expr<'tcx> {
30 let temp_lifetime = cx.region_scope_tree.temporary_scope(self.hir_id.local_id);
31 let expr_scope = region::Scope {
32 id: self.hir_id.local_id,
33 data: region::ScopeData::Node
36 debug!("Expr::make_mirror(): id={}, span={:?}", self.id, self.span);
38 let mut expr = make_mirror_unadjusted(cx, self);
40 // Now apply adjustments, if any.
41 for adjustment in cx.tables().expr_adjustments(self) {
42 debug!("make_mirror: expr={:?} applying adjustment={:?}",
45 expr = apply_adjustment(cx, self, expr, adjustment);
48 // Next, wrap this up in the expr's scope.
53 kind: ExprKind::Scope {
54 region_scope: expr_scope,
56 lint_level: cx.lint_level_of(self.id),
60 // Finally, create a destruction scope, if any.
61 if let Some(region_scope) =
62 cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id) {
67 kind: ExprKind::Scope {
70 lint_level: LintLevel::Inherited,
80 fn apply_adjustment<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
81 hir_expr: &'tcx hir::Expr,
83 adjustment: &Adjustment<'tcx>)
85 let Expr { temp_lifetime, mut span, .. } = expr;
86 let kind = match adjustment.kind {
87 Adjust::ReifyFnPointer => {
88 ExprKind::ReifyFnPointer { source: expr.to_ref() }
90 Adjust::UnsafeFnPointer => {
91 ExprKind::UnsafeFnPointer { source: expr.to_ref() }
93 Adjust::ClosureFnPointer => {
94 ExprKind::ClosureFnPointer { source: expr.to_ref() }
96 Adjust::NeverToAny => {
97 ExprKind::NeverToAny { source: expr.to_ref() }
99 Adjust::MutToConstPointer => {
100 ExprKind::Cast { source: expr.to_ref() }
102 Adjust::Deref(None) => {
103 // Adjust the span from the block, to the last expression of the
104 // block. This is a better span when returning a mutable reference
105 // with too short a lifetime. The error message will use the span
106 // from the assignment to the return place, which should only point
107 // at the returned value, not the entire function body.
109 // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
111 // // ^ error message points at this expression.
114 // We don't need to do this adjustment in the next match arm since
115 // deref coercions always start with a built-in deref.
116 if let ExprKind::Block { body } = expr.kind {
117 if let Some(ref last_expr) = body.expr {
118 span = last_expr.span;
122 ExprKind::Deref { arg: expr.to_ref() }
124 Adjust::Deref(Some(deref)) => {
125 let call = deref.method_call(cx.tcx(), expr.ty);
129 ty: cx.tcx.mk_ref(deref.region,
135 kind: ExprKind::Borrow {
136 region: deref.region,
137 borrow_kind: deref.mutbl.to_borrow_kind(),
142 overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
144 Adjust::Borrow(AutoBorrow::Ref(r, m)) => {
147 borrow_kind: m.to_borrow_kind(),
151 Adjust::Borrow(AutoBorrow::RawPtr(m)) => {
152 // Convert this to a suitable `&foo` and
153 // then an unsafe coercion. Limit the region to be just this
155 let region = ty::ReScope(region::Scope {
156 id: hir_expr.hir_id.local_id,
157 data: region::ScopeData::Node
159 let region = cx.tcx.mk_region(region);
162 ty: cx.tcx.mk_ref(region,
168 kind: ExprKind::Borrow {
170 borrow_kind: m.to_borrow_kind(),
174 let cast_expr = Expr {
176 ty: adjustment.target,
178 kind: ExprKind::Cast { source: expr.to_ref() }
181 // To ensure that both implicit and explicit coercions are
182 // handled the same way, we insert an extra layer of indirection here.
183 // For explicit casts (e.g. 'foo as *const T'), the source of the 'Use'
184 // will be an ExprKind::Hair with the appropriate cast expression. Here,
185 // we make our Use source the generated Cast from the original coercion.
187 // In both cases, this outer 'Use' ensures that the inner 'Cast' is handled by
188 // as_operand, not by as_rvalue - causing the cast result to be stored in a temporary.
189 // Ordinary, this is identical to using the cast directly as an rvalue. However, if the
190 // source of the cast was previously borrowed as mutable, storing the cast in a
191 // temporary gives the source a chance to expire before the cast is used. For
192 // structs with a self-referential *mut ptr, this allows assignment to work as
195 // For example, consider the type 'struct Foo { field: *mut Foo }',
196 // The method 'fn bar(&mut self) { self.field = self }'
197 // triggers a coercion from '&mut self' to '*mut self'. In order
198 // for the assignment to be valid, the implicit borrow
199 // of 'self' involved in the coercion needs to end before the local
200 // containing the '*mut T' is assigned to 'self.field' - otherwise,
201 // we end up trying to assign to 'self.field' while we have another mutable borrow
204 // We only need to worry about this kind of thing for coercions from refs to ptrs,
205 // since they get rid of a borrow implicitly.
206 ExprKind::Use { source: cast_expr.to_ref() }
209 // See the above comment for Adjust::Deref
210 if let ExprKind::Block { body } = expr.kind {
211 if let Some(ref last_expr) = body.expr {
212 span = last_expr.span;
216 ExprKind::Unsize { source: expr.to_ref() }
222 ty: adjustment.target,
228 fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
229 expr: &'tcx hir::Expr)
231 let expr_ty = cx.tables().expr_ty(expr);
232 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
234 let kind = match expr.node {
235 // Here comes the interesting stuff:
236 hir::ExprKind::MethodCall(_, method_span, ref args) => {
237 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
238 let expr = method_callee(cx, expr, method_span,None);
239 let args = args.iter()
250 hir::ExprKind::Call(ref fun, ref args) => {
251 if cx.tables().is_method_call(expr) {
252 // The callee is something implementing Fn, FnMut, or FnOnce.
253 // Find the actual method implementation being called and
254 // build the appropriate UFCS call expression with the
255 // callee-object as expr parameter.
257 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
259 let method = method_callee(cx, expr, fun.span,None);
261 let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
262 let tupled_args = Expr {
263 ty: cx.tcx.mk_tup(arg_tys),
266 kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
271 fun: method.to_ref(),
272 args: vec![fun.to_ref(), tupled_args.to_ref()],
276 let adt_data = if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) =
279 // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
280 expr_ty.ty_adt_def().and_then(|adt_def| {
282 Def::VariantCtor(variant_id, CtorKind::Fn) => {
283 Some((adt_def, adt_def.variant_index_with_id(variant_id)))
285 Def::StructCtor(_, CtorKind::Fn) |
286 Def::SelfCtor(..) => Some((adt_def, 0)),
293 if let Some((adt_def, index)) = adt_data {
294 let substs = cx.tables().node_substs(fun.hir_id);
296 let user_ty = cx.tables().user_substs(fun.hir_id)
298 user_substs.unchecked_map(|user_substs| {
299 // Here, we just pair an `AdtDef` with the
300 // `user_substs`, so no new types etc are introduced.
301 cx.tcx().mk_adt(adt_def, user_substs)
305 let field_refs = args.iter()
309 name: Field::new(idx),
317 variant_index: index,
324 ty: cx.tables().node_id_to_type(fun.hir_id),
333 hir::ExprKind::AddrOf(mutbl, ref expr) => {
334 let region = match expr_ty.sty {
335 ty::Ref(r, _, _) => r,
336 _ => span_bug!(expr.span, "type of & not region"),
340 borrow_kind: mutbl.to_borrow_kind(),
345 hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
347 hir::ExprKind::Assign(ref lhs, ref rhs) => {
354 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
355 if cx.tables().is_method_call(expr) {
356 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
366 hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
367 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
371 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
372 if cx.tables().is_method_call(expr) {
373 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
376 match (op.node, cx.constness) {
377 // FIXME(eddyb) use logical ops in constants when
378 // they can handle that kind of control-flow.
379 (hir::BinOpKind::And, hir::Constness::Const) => {
386 (hir::BinOpKind::Or, hir::Constness::Const) => {
394 (hir::BinOpKind::And, hir::Constness::NotConst) => {
395 ExprKind::LogicalOp {
401 (hir::BinOpKind::Or, hir::Constness::NotConst) => {
402 ExprKind::LogicalOp {
410 let op = bin_op(op.node);
421 hir::ExprKind::Index(ref lhs, ref index) => {
422 if cx.tables().is_method_call(expr) {
423 overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
427 index: index.to_ref(),
432 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
433 if cx.tables().is_method_call(expr) {
434 overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
436 ExprKind::Deref { arg: arg.to_ref() }
440 hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
441 if cx.tables().is_method_call(expr) {
442 overloaded_operator(cx, expr, vec![arg.to_ref()])
451 hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
452 if cx.tables().is_method_call(expr) {
453 overloaded_operator(cx, expr, vec![arg.to_ref()])
455 if let hir::ExprKind::Lit(ref lit) = arg.node {
457 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
469 hir::ExprKind::Struct(ref qpath, ref fields, ref base) => {
471 ty::Adt(adt, substs) => {
472 match adt.adt_kind() {
473 AdtKind::Struct | AdtKind::Union => {
478 user_ty: user_annotated_ty_for_adt(cx, expr.hir_id, adt),
479 fields: field_refs(cx, fields),
480 base: base.as_ref().map(|base| {
483 field_types: cx.tables()
484 .fru_field_types()[expr.hir_id]
491 let def = match *qpath {
492 hir::QPath::Resolved(_, ref path) => path.def,
493 hir::QPath::TypeRelative(..) => Def::Err,
496 Def::Variant(variant_id) => {
497 assert!(base.is_none());
499 let index = adt.variant_index_with_id(variant_id);
502 variant_index: index,
504 user_ty: user_annotated_ty_for_adt(cx, expr.hir_id, adt),
505 fields: field_refs(cx, fields),
510 span_bug!(expr.span, "unexpected def: {:?}", def);
518 "unexpected type for struct literal: {:?}",
524 hir::ExprKind::Closure(..) => {
525 let closure_ty = cx.tables().expr_ty(expr);
526 let (def_id, substs, movability) = match closure_ty.sty {
527 ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
528 ty::Generator(def_id, substs, movability) => {
529 (def_id, UpvarSubsts::Generator(substs), Some(movability))
532 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
535 let upvars = cx.tcx.with_freevars(expr.id, |freevars| {
537 .zip(substs.upvar_tys(def_id, cx.tcx))
538 .map(|(fv, ty)| capture_freevar(cx, expr, fv, ty))
549 hir::ExprKind::Path(ref qpath) => {
550 let def = cx.tables().qpath_def(qpath, expr.hir_id);
551 convert_path_expr(cx, expr, def)
554 hir::ExprKind::InlineAsm(ref asm, ref outputs, ref inputs) => {
555 ExprKind::InlineAsm {
557 outputs: outputs.to_ref(),
558 inputs: inputs.to_ref(),
562 // Now comes the rote stuff:
563 hir::ExprKind::Repeat(ref v, ref count) => {
564 let def_id = cx.tcx.hir.local_def_id(count.id);
565 let substs = Substs::identity_for_item(cx.tcx.global_tcx(), def_id);
566 let instance = ty::Instance::resolve(
572 let global_id = GlobalId {
576 let span = cx.tcx.def_span(def_id);
577 let count = match cx.tcx.at(span).const_eval(cx.param_env.and(global_id)) {
578 Ok(cv) => cv.unwrap_usize(cx.tcx),
580 e.report_as_error(cx.tcx.at(span), "could not evaluate array length");
590 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
591 hir::ExprKind::Break(dest, ref value) => {
592 match dest.target_id {
593 Ok(target_id) => ExprKind::Break {
594 label: region::Scope {
595 id: cx.tcx.hir.node_to_hir_id(target_id).local_id,
596 data: region::ScopeData::Node
598 value: value.to_ref(),
600 Err(err) => bug!("invalid loop id for break: {}", err)
603 hir::ExprKind::Continue(dest) => {
604 match dest.target_id {
605 Ok(loop_id) => ExprKind::Continue {
606 label: region::Scope {
607 id: cx.tcx.hir.node_to_hir_id(loop_id).local_id,
608 data: region::ScopeData::Node
611 Err(err) => bug!("invalid loop id for continue: {}", err)
614 hir::ExprKind::Match(ref discr, ref arms, _) => {
616 discriminant: discr.to_ref(),
617 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
620 hir::ExprKind::If(ref cond, ref then, ref otherwise) => {
622 condition: cond.to_ref(),
624 otherwise: otherwise.to_ref(),
627 hir::ExprKind::While(ref cond, ref body, _) => {
629 condition: Some(cond.to_ref()),
630 body: block::to_expr_ref(cx, body),
633 hir::ExprKind::Loop(ref body, _, _) => {
636 body: block::to_expr_ref(cx, body),
639 hir::ExprKind::Field(ref source, ..) => {
641 lhs: source.to_ref(),
642 name: Field::new(cx.tcx.field_index(expr.id, cx.tables)),
645 hir::ExprKind::Cast(ref source, _) => {
646 // Check to see if this cast is a "coercion cast", where the cast is actually done
647 // using a coercion (or is a no-op).
648 if let Some(&TyCastKind::CoercionCast) = cx.tables()
650 .get(source.hir_id) {
651 // Convert the lexpr to a vexpr.
652 ExprKind::Use { source: source.to_ref() }
654 // check whether this is casting an enum variant discriminant
655 // to prevent cycles, we refer to the discriminant initializer
656 // which is always an integer and thus doesn't need to know the
657 // enum's layout (or its tag type) to compute it during const eval
661 // B = A as isize + 4,
663 // The correct solution would be to add symbolic computations to miri,
664 // so we wouldn't have to compute and store the actual value
665 let var = if let hir::ExprKind::Path(ref qpath) = source.node {
666 let def = cx.tables().qpath_def(qpath, source.hir_id);
669 .node_id_to_type(source.hir_id)
671 .and_then(|adt_def| {
673 Def::VariantCtor(variant_id, CtorKind::Const) => {
674 let idx = adt_def.variant_index_with_id(variant_id);
675 let (d, o) = adt_def.discriminant_def_for_variant(idx);
676 use rustc::ty::util::IntTypeExt;
677 let ty = adt_def.repr.discr_type();
678 let ty = ty.to_ty(cx.tcx());
687 let source = if let Some((did, offset, ty)) = var {
688 let mk_const = |literal| Expr {
692 kind: ExprKind::Literal { literal, user_ty: None },
694 let offset = mk_const(ty::Const::from_bits(
697 cx.param_env.and(ty),
701 // in case we are offsetting from a computed discriminant
702 // and not the beginning of discriminants (which is always `0`)
703 let substs = Substs::identity_for_item(cx.tcx(), did);
704 let lhs = mk_const(ty::Const::unevaluated(cx.tcx(), did, substs, ty));
705 let bin = ExprKind::Binary {
722 ExprKind::Cast { source }
725 hir::ExprKind::Type(ref source, ref ty) => {
726 let user_provided_tys = cx.tables.user_provided_tys();
727 let user_ty = *user_provided_tys
729 .expect(&format!("{:?} not found in user_provided_tys, source: {:?}", ty, source));
730 if source.is_place_expr() {
731 ExprKind::PlaceTypeAscription {
732 source: source.to_ref(),
736 ExprKind::ValueTypeAscription {
737 source: source.to_ref(),
742 hir::ExprKind::Box(ref value) => {
744 value: value.to_ref(),
747 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
748 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
750 hir::ExprKind::Yield(ref v) => ExprKind::Yield { value: v.to_ref() },
761 fn user_annotated_ty_for_def(
762 cx: &mut Cx<'a, 'gcx, 'tcx>,
765 ) -> Option<CanonicalTy<'tcx>> {
767 // A reference to something callable -- e.g., a fn, method, or
768 // a tuple-struct or tuple-variant. This has the type of a
769 // `Fn` but with the user-given substitutions.
772 Def::StructCtor(_, CtorKind::Fn) |
773 Def::VariantCtor(_, CtorKind::Fn) =>
774 Some(cx.tables().user_substs(hir_id)?.unchecked_map(|user_substs| {
775 // Here, we just pair a `DefId` with the
776 // `user_substs`, so no new types etc are introduced.
777 cx.tcx().mk_fn_def(def.def_id(), user_substs)
780 Def::Const(_def_id) |
781 Def::AssociatedConst(_def_id) =>
782 bug!("unimplemented"),
784 // A unit struct/variant which is used as a value (e.g.,
785 // `None`). This has the type of the enum/struct that defines
786 // this variant -- but with the substitutions given by the
788 Def::StructCtor(_def_id, CtorKind::Const) |
789 Def::VariantCtor(_def_id, CtorKind::Const) =>
790 match &cx.tables().node_id_to_type(hir_id).sty {
791 ty::Adt(adt_def, _) => user_annotated_ty_for_adt(cx, hir_id, adt_def),
792 sty => bug!("unexpected sty: {:?}", sty),
795 // `Self` is used in expression as a tuple struct constructor or an unit struct constructor
796 Def::SelfCtor(_) => {
797 let sty = &cx.tables().node_id_to_type(hir_id).sty;
799 ty::FnDef(ref def_id, _) => {
800 Some(cx.tables().user_substs(hir_id)?.unchecked_map(|user_substs| {
801 // Here, we just pair a `DefId` with the
802 // `user_substs`, so no new types etc are introduced.
803 cx.tcx().mk_fn_def(*def_id, user_substs)
806 ty::Adt(ref adt_def, _) => {
807 user_annotated_ty_for_adt(cx, hir_id, adt_def)
810 bug!("unexpected sty: {:?}", sty)
815 bug!("user_annotated_ty_for_def: unexpected def {:?} at {:?}", def, hir_id)
819 fn user_annotated_ty_for_adt(
820 cx: &mut Cx<'a, 'gcx, 'tcx>,
822 adt_def: &'tcx AdtDef,
823 ) -> Option<CanonicalTy<'tcx>> {
824 let user_substs = cx.tables().user_substs(hir_id)?;
825 Some(user_substs.unchecked_map(|user_substs| {
826 // Here, we just pair an `AdtDef` with the
827 // `user_substs`, so no new types etc are introduced.
828 cx.tcx().mk_adt(adt_def, user_substs)
832 fn method_callee<'a, 'gcx, 'tcx>(
833 cx: &mut Cx<'a, 'gcx, 'tcx>,
836 overloaded_callee: Option<(DefId, &'tcx Substs<'tcx>)>,
838 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
839 let (def_id, substs, user_ty) = match overloaded_callee {
840 Some((def_id, substs)) => (def_id, substs, None),
842 let type_dependent_defs = cx.tables().type_dependent_defs();
843 let def = type_dependent_defs
846 span_bug!(expr.span, "no type-dependent def for method callee")
848 let user_ty = user_annotated_ty_for_def(cx, expr.hir_id, def);
849 (def.def_id(), cx.tables().node_substs(expr.hir_id), user_ty)
852 let ty = cx.tcx().mk_fn_def(def_id, substs);
857 kind: ExprKind::Literal {
858 literal: ty::Const::zero_sized(cx.tcx(), ty),
864 trait ToBorrowKind { fn to_borrow_kind(&self) -> BorrowKind; }
866 impl ToBorrowKind for AutoBorrowMutability {
867 fn to_borrow_kind(&self) -> BorrowKind {
868 use rustc::ty::adjustment::AllowTwoPhase;
870 AutoBorrowMutability::Mutable { allow_two_phase_borrow } =>
871 BorrowKind::Mut { allow_two_phase_borrow: match allow_two_phase_borrow {
872 AllowTwoPhase::Yes => true,
873 AllowTwoPhase::No => false
875 AutoBorrowMutability::Immutable =>
881 impl ToBorrowKind for hir::Mutability {
882 fn to_borrow_kind(&self) -> BorrowKind {
884 hir::MutMutable => BorrowKind::Mut { allow_two_phase_borrow: false },
885 hir::MutImmutable => BorrowKind::Shared,
890 fn convert_arm<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
892 patterns: arm.pats.iter().map(|p| cx.pattern_from_hir(p)).collect(),
893 guard: match arm.guard {
894 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
897 body: arm.body.to_ref(),
899 lint_level: LintLevel::Inherited,
903 fn convert_path_expr<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
904 expr: &'tcx hir::Expr,
907 let substs = cx.tables().node_substs(expr.hir_id);
909 // A regular function, constructor function or a constant.
912 Def::StructCtor(_, CtorKind::Fn) |
913 Def::VariantCtor(_, CtorKind::Fn) |
914 Def::SelfCtor(..) => {
915 let user_ty = user_annotated_ty_for_def(cx, expr.hir_id, &def);
917 literal: ty::Const::zero_sized(
919 cx.tables().node_id_to_type(expr.hir_id),
926 Def::AssociatedConst(def_id) => ExprKind::Literal {
927 literal: ty::Const::unevaluated(
931 cx.tables().node_id_to_type(expr.hir_id),
933 user_ty: None, // FIXME(#47184) -- user given type annot on constants
936 Def::StructCtor(def_id, CtorKind::Const) |
937 Def::VariantCtor(def_id, CtorKind::Const) => {
938 match cx.tables().node_id_to_type(expr.hir_id).sty {
939 // A unit struct/variant which is used as a value.
940 // We return a completely different ExprKind here to account for this special case.
941 ty::Adt(adt_def, substs) => {
944 variant_index: adt_def.variant_index_with_id(def_id),
946 user_ty: user_annotated_ty_for_adt(cx, expr.hir_id, adt_def),
951 ref sty => bug!("unexpected sty: {:?}", sty),
955 Def::Static(node_id, _) => ExprKind::StaticRef { id: node_id },
957 Def::Local(..) | Def::Upvar(..) => convert_var(cx, expr, def),
959 _ => span_bug!(expr.span, "def `{:?}` not yet implemented", def),
963 fn convert_var<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
964 expr: &'tcx hir::Expr,
967 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
970 Def::Local(id) => ExprKind::VarRef { id },
972 Def::Upvar(var_id, index, closure_expr_id) => {
973 debug!("convert_var(upvar({:?}, {:?}, {:?}))",
977 let var_hir_id = cx.tcx.hir.node_to_hir_id(var_id);
978 let var_ty = cx.tables().node_id_to_type(var_hir_id);
980 // FIXME free regions in closures are not right
981 let closure_ty = cx.tables()
982 .node_id_to_type(cx.tcx.hir.node_to_hir_id(closure_expr_id));
984 // FIXME we're just hard-coding the idea that the
985 // signature will be &self or &mut self and hence will
986 // have a bound region with number 0
987 let closure_def_id = cx.tcx.hir.local_def_id(closure_expr_id);
988 let region = ty::ReFree(ty::FreeRegion {
989 scope: closure_def_id,
990 bound_region: ty::BoundRegion::BrAnon(0),
992 let region = cx.tcx.mk_region(region);
994 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.sty {
995 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
996 ty::ClosureKind::Fn => {
997 let ref_closure_ty = cx.tcx.mk_ref(region,
1000 mutbl: hir::MutImmutable,
1004 temp_lifetime: temp_lifetime,
1006 kind: ExprKind::Deref {
1011 kind: ExprKind::SelfRef,
1017 ty::ClosureKind::FnMut => {
1018 let ref_closure_ty = cx.tcx.mk_ref(region,
1021 mutbl: hir::MutMutable,
1027 kind: ExprKind::Deref {
1032 kind: ExprKind::SelfRef,
1037 ty::ClosureKind::FnOnce => {
1042 kind: ExprKind::SelfRef,
1051 kind: ExprKind::SelfRef,
1055 // at this point we have `self.n`, which loads up the upvar
1056 let field_kind = ExprKind::Field {
1057 lhs: self_expr.to_ref(),
1058 name: Field::new(index),
1061 // ...but the upvar might be an `&T` or `&mut T` capture, at which
1062 // point we need an implicit deref
1063 let upvar_id = ty::UpvarId {
1065 closure_expr_id: LocalDefId::from_def_id(closure_def_id),
1067 match cx.tables().upvar_capture(upvar_id) {
1068 ty::UpvarCapture::ByValue => field_kind,
1069 ty::UpvarCapture::ByRef(borrow) => {
1073 ty: cx.tcx.mk_ref(borrow.region,
1076 mutbl: borrow.kind.to_mutbl_lossy(),
1086 _ => span_bug!(expr.span, "type of & not region"),
1091 fn bin_op(op: hir::BinOpKind) -> BinOp {
1093 hir::BinOpKind::Add => BinOp::Add,
1094 hir::BinOpKind::Sub => BinOp::Sub,
1095 hir::BinOpKind::Mul => BinOp::Mul,
1096 hir::BinOpKind::Div => BinOp::Div,
1097 hir::BinOpKind::Rem => BinOp::Rem,
1098 hir::BinOpKind::BitXor => BinOp::BitXor,
1099 hir::BinOpKind::BitAnd => BinOp::BitAnd,
1100 hir::BinOpKind::BitOr => BinOp::BitOr,
1101 hir::BinOpKind::Shl => BinOp::Shl,
1102 hir::BinOpKind::Shr => BinOp::Shr,
1103 hir::BinOpKind::Eq => BinOp::Eq,
1104 hir::BinOpKind::Lt => BinOp::Lt,
1105 hir::BinOpKind::Le => BinOp::Le,
1106 hir::BinOpKind::Ne => BinOp::Ne,
1107 hir::BinOpKind::Ge => BinOp::Ge,
1108 hir::BinOpKind::Gt => BinOp::Gt,
1109 _ => bug!("no equivalent for ast binop {:?}", op),
1113 fn overloaded_operator<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1114 expr: &'tcx hir::Expr,
1115 args: Vec<ExprRef<'tcx>>)
1117 let fun = method_callee(cx, expr, expr.span, None);
1122 from_hir_call: false,
1126 fn overloaded_place<'a, 'gcx, 'tcx>(
1127 cx: &mut Cx<'a, 'gcx, 'tcx>,
1128 expr: &'tcx hir::Expr,
1130 overloaded_callee: Option<(DefId, &'tcx Substs<'tcx>)>,
1131 args: Vec<ExprRef<'tcx>>,
1132 ) -> ExprKind<'tcx> {
1133 // For an overloaded *x or x[y] expression of type T, the method
1134 // call returns an &T and we must add the deref so that the types
1135 // line up (this is because `*x` and `x[y]` represent places):
1137 let recv_ty = match args[0] {
1138 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
1139 ExprRef::Mirror(ref e) => e.ty
1142 // Reconstruct the output assuming it's a reference with the
1143 // same region and mutability as the receiver. This holds for
1144 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
1145 let (region, mutbl) = match recv_ty.sty {
1146 ty::Ref(region, _, mutbl) => (region, mutbl),
1147 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
1149 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut {
1154 // construct the complete expression `foo()` for the overloaded call,
1155 // which will yield the &T type
1156 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
1157 let fun = method_callee(cx, expr, expr.span, overloaded_callee);
1158 let ref_expr = Expr {
1162 kind: ExprKind::Call {
1166 from_hir_call: false,
1170 // construct and return a deref wrapper `*foo()`
1171 ExprKind::Deref { arg: ref_expr.to_ref() }
1174 fn capture_freevar<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1175 closure_expr: &'tcx hir::Expr,
1176 freevar: &hir::Freevar,
1177 freevar_ty: Ty<'tcx>)
1179 let var_hir_id = cx.tcx.hir.node_to_hir_id(freevar.var_id());
1180 let upvar_id = ty::UpvarId {
1182 closure_expr_id: cx.tcx.hir.local_def_id(closure_expr.id).to_local(),
1184 let upvar_capture = cx.tables().upvar_capture(upvar_id);
1185 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1186 let var_ty = cx.tables().node_id_to_type(var_hir_id);
1187 let captured_var = Expr {
1190 span: closure_expr.span,
1191 kind: convert_var(cx, closure_expr, freevar.def),
1193 match upvar_capture {
1194 ty::UpvarCapture::ByValue => captured_var.to_ref(),
1195 ty::UpvarCapture::ByRef(upvar_borrow) => {
1196 let borrow_kind = match upvar_borrow.kind {
1197 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1198 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1199 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false }
1204 span: closure_expr.span,
1205 kind: ExprKind::Borrow {
1206 region: upvar_borrow.region,
1208 arg: captured_var.to_ref(),
1215 /// Converts a list of named fields (i.e. for struct-like struct/enum ADTs) into FieldExprRef.
1216 fn field_refs<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
1217 fields: &'tcx [hir::Field])
1218 -> Vec<FieldExprRef<'tcx>> {
1222 name: Field::new(cx.tcx.field_index(field.id, cx.tables)),
1223 expr: field.expr.to_ref(),