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::fnv::FnvHashMap;
15 use hair::cx::to_ref::ToRef;
16 use rustc::front::map;
17 use rustc::middle::def::Def;
18 use rustc::middle::const_eval;
19 use rustc::middle::region::CodeExtent;
20 use rustc::middle::pat_util;
21 use rustc::middle::ty::{self, VariantDef, Ty};
22 use rustc::mir::repr::*;
24 use rustc_front::util as hir_util;
25 use syntax::parse::token;
28 impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
29 type Output = Expr<'tcx>;
31 fn make_mirror<'a>(self, cx: &mut Cx<'a, 'tcx>) -> Expr<'tcx> {
32 debug!("Expr::make_mirror(): id={}, span={:?}", self.id, self.span);
34 let expr_ty = cx.tcx.expr_ty(self); // note: no adjustments (yet)!
35 let temp_lifetime = cx.tcx.region_maps.temporary_scope(self.id);
36 let expr_extent = cx.tcx.region_maps.node_extent(self.id);
38 let kind = match self.node {
39 // Here comes the interesting stuff:
40 hir::ExprMethodCall(_, _, ref args) => {
41 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
42 let expr = method_callee(cx, self, ty::MethodCall::expr(self.id));
43 let args = args.iter()
53 hir::ExprCall(ref fun, ref args) => {
54 if cx.tcx.is_method_call(self.id) {
55 // The callee is something implementing Fn, FnMut, or FnOnce.
56 // Find the actual method implementation being called and
57 // build the appropriate UFCS call expression with the
58 // callee-object as self parameter.
60 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
62 let method = method_callee(cx, self, ty::MethodCall::expr(self.id));
64 let sig = match method.ty.sty {
65 ty::TyBareFn(_, fn_ty) => &fn_ty.sig,
66 _ => cx.tcx.sess.span_bug(self.span, "type of method is not an fn")
69 let sig = cx.tcx.no_late_bound_regions(sig).unwrap_or_else(|| {
70 cx.tcx.sess.span_bug(self.span, "method call has late-bound regions")
73 assert_eq!(sig.inputs.len(), 2);
75 let tupled_args = Expr {
77 temp_lifetime: temp_lifetime,
79 kind: ExprKind::Tuple {
80 fields: args.iter().map(ToRef::to_ref).collect()
87 args: vec![fun.to_ref(), tupled_args.to_ref()]
90 let adt_data = if let hir::ExprPath(..) = fun.node {
91 // Tuple-like ADTs are represented as ExprCall. We convert them here.
92 expr_ty.ty_adt_def().and_then(|adt_def|{
93 match cx.tcx.def_map.borrow()[&fun.id].full_def() {
94 Def::Variant(_, variant_id) => {
95 Some((adt_def, adt_def.variant_index_with_id(variant_id)))
104 if let Some((adt_def, index)) = adt_data {
105 let substs = cx.tcx.mk_substs(cx.tcx.node_id_item_substs(fun.id).substs);
106 let field_refs = args.iter().enumerate().map(|(idx, e)| FieldExprRef {
107 name: Field::new(idx),
113 variant_index: index,
119 ty: cx.tcx.node_id_to_type(fun.id),
127 hir::ExprAddrOf(mutbl, ref expr) => {
128 let region = match expr_ty.sty {
129 ty::TyRef(r, _) => r,
130 _ => cx.tcx.sess.span_bug(expr.span, "type of & not region"),
134 borrow_kind: to_borrow_kind(mutbl),
139 hir::ExprBlock(ref blk) => {
140 ExprKind::Block { body: &blk }
143 hir::ExprAssign(ref lhs, ref rhs) => {
150 hir::ExprAssignOp(op, ref lhs, ref rhs) => {
151 if cx.tcx.is_method_call(self.id) {
152 let pass_args = if hir_util::is_by_value_binop(op.node) {
157 overloaded_operator(cx, self, ty::MethodCall::expr(self.id),
158 pass_args, lhs.to_ref(), vec![rhs])
168 hir::ExprLit(..) => ExprKind::Literal {
169 literal: cx.const_eval_literal(self)
172 hir::ExprBinary(op, ref lhs, ref rhs) => {
173 if cx.tcx.is_method_call(self.id) {
174 let pass_args = if hir_util::is_by_value_binop(op.node) {
179 overloaded_operator(cx, self, ty::MethodCall::expr(self.id),
180 pass_args, lhs.to_ref(), vec![rhs])
184 hir::BinOp_::BiAnd => {
185 ExprKind::LogicalOp {
191 hir::BinOp_::BiOr => {
192 ExprKind::LogicalOp {
199 let op = bin_op(op.node);
210 hir::ExprIndex(ref lhs, ref index) => {
211 if cx.tcx.is_method_call(self.id) {
212 overloaded_lvalue(cx, self, ty::MethodCall::expr(self.id),
213 PassArgs::ByValue, lhs.to_ref(), vec![index])
217 index: index.to_ref(),
222 hir::ExprUnary(hir::UnOp::UnDeref, ref arg) => {
223 if cx.tcx.is_method_call(self.id) {
224 overloaded_lvalue(cx, self, ty::MethodCall::expr(self.id),
225 PassArgs::ByValue, arg.to_ref(), vec![])
227 ExprKind::Deref { arg: arg.to_ref() }
231 hir::ExprUnary(op, ref arg) => {
232 if cx.tcx.is_method_call(self.id) {
233 overloaded_operator(cx, self, ty::MethodCall::expr(self.id),
234 PassArgs::ByValue, arg.to_ref(), vec![])
238 hir::UnOp::UnNot => UnOp::Not,
239 hir::UnOp::UnNeg => UnOp::Neg,
240 hir::UnOp::UnDeref => {
241 cx.tcx.sess.span_bug(
243 "UnDeref should have been handled elsewhere");
253 hir::ExprStruct(_, ref fields, ref base) => {
255 ty::TyStruct(adt, substs) => {
256 let field_refs = field_refs(&adt.variants[0], fields);
262 base: base.as_ref().map(|base| {
265 field_types: cx.tcx.tables
267 .fru_field_types[&self.id]
273 ty::TyEnum(adt, substs) => {
274 match cx.tcx.def_map.borrow()[&self.id].full_def() {
275 Def::Variant(enum_id, variant_id) => {
276 debug_assert!(adt.did == enum_id);
277 assert!(base.is_none());
279 let index = adt.variant_index_with_id(variant_id);
280 let field_refs = field_refs(&adt.variants[index], fields);
283 variant_index: index,
290 cx.tcx.sess.span_bug(
292 &format!("unexpected def: {:?}", def));
297 cx.tcx.sess.span_bug(
299 &format!("unexpected type for struct literal: {:?}", expr_ty));
304 hir::ExprClosure(..) => {
305 let closure_ty = cx.tcx.expr_ty(self);
306 let (def_id, substs) = match closure_ty.sty {
307 ty::TyClosure(def_id, ref substs) => (def_id, substs),
309 cx.tcx.sess.span_bug(self.span,
310 &format!("closure expr w/o closure type: {:?}",
314 let upvars = cx.tcx.with_freevars(self.id, |freevars| {
317 .map(|(i, fv)| capture_freevar(cx, self, fv, substs.upvar_tys[i]))
327 hir::ExprRange(ref start, ref end) => {
328 let range_ty = cx.tcx.expr_ty(self);
329 let (adt_def, substs) = match range_ty.sty {
330 ty::TyStruct(adt_def, substs) => (adt_def, substs),
332 cx.tcx.sess.span_bug(self.span, "unexpanded ast");
336 let field_expr_ref = |s: &'tcx P<hir::Expr>, name: &str| {
337 let name = token::intern(name);
338 let index = adt_def.variants[0].index_of_field_named(name).unwrap();
339 FieldExprRef { name: Field::new(index), expr: s.to_ref() }
342 let start_field = start.as_ref()
344 .map(|s| field_expr_ref(s, "start"));
346 let end_field = end.as_ref()
348 .map(|e| field_expr_ref(e, "end"));
354 fields: start_field.chain(end_field).collect(),
359 hir::ExprPath(..) => {
360 convert_path_expr(cx, self)
363 hir::ExprInlineAsm(ref asm) => {
364 ExprKind::InlineAsm { asm: asm }
367 // Now comes the rote stuff:
369 hir::ExprRepeat(ref v, ref c) => ExprKind::Repeat {
371 count: TypedConstVal {
372 ty: cx.tcx.expr_ty(c),
374 value: const_eval::eval_const_expr(cx.tcx, c)
377 hir::ExprRet(ref v) =>
378 ExprKind::Return { value: v.to_ref() },
379 hir::ExprBreak(label) =>
380 ExprKind::Break { label: label.map(|_| loop_label(cx, self)) },
381 hir::ExprAgain(label) =>
382 ExprKind::Continue { label: label.map(|_| loop_label(cx, self)) },
383 hir::ExprMatch(ref discr, ref arms, _) =>
384 ExprKind::Match { discriminant: discr.to_ref(),
385 arms: arms.iter().map(|a| convert_arm(cx, a)).collect() },
386 hir::ExprIf(ref cond, ref then, ref otherwise) =>
387 ExprKind::If { condition: cond.to_ref(),
388 then: block::to_expr_ref(cx, then),
389 otherwise: otherwise.to_ref() },
390 hir::ExprWhile(ref cond, ref body, _) =>
391 ExprKind::Loop { condition: Some(cond.to_ref()),
392 body: block::to_expr_ref(cx, body) },
393 hir::ExprLoop(ref body, _) =>
394 ExprKind::Loop { condition: None,
395 body: block::to_expr_ref(cx, body) },
396 hir::ExprField(ref source, name) => {
397 let index = match cx.tcx.expr_ty_adjusted(source).sty {
398 ty::TyStruct(adt_def, _) =>
399 adt_def.variants[0].index_of_field_named(name.node),
401 cx.tcx.sess.span_bug(
403 &format!("field of non-struct: {:?}", ty)),
405 let index = index.unwrap_or_else(|| {
406 cx.tcx.sess.span_bug(
408 &format!("no index found for field `{}`", name.node));
410 ExprKind::Field { lhs: source.to_ref(), name: Field::new(index) }
412 hir::ExprTupField(ref source, index) =>
413 ExprKind::Field { lhs: source.to_ref(),
414 name: Field::new(index.node as usize) },
415 hir::ExprCast(ref source, _) =>
416 ExprKind::Cast { source: source.to_ref() },
417 hir::ExprType(ref source, _) =>
418 return source.make_mirror(cx),
419 hir::ExprBox(ref value) =>
421 value: value.to_ref(),
422 value_extents: cx.tcx.region_maps.node_extent(value.id)
424 hir::ExprVec(ref fields) =>
425 ExprKind::Vec { fields: fields.to_ref() },
426 hir::ExprTup(ref fields) =>
427 ExprKind::Tuple { fields: fields.to_ref() },
430 let mut expr = Expr {
431 temp_lifetime: temp_lifetime,
437 debug!("make_mirror: unadjusted-expr={:?} applying adjustments={:?}",
438 expr, cx.tcx.tables.borrow().adjustments.get(&self.id));
440 // Now apply adjustments, if any.
441 match cx.tcx.tables.borrow().adjustments.get(&self.id) {
443 Some(&ty::adjustment::AdjustReifyFnPointer) => {
444 let adjusted_ty = cx.tcx.expr_ty_adjusted(self);
446 temp_lifetime: temp_lifetime,
449 kind: ExprKind::ReifyFnPointer { source: expr.to_ref() },
452 Some(&ty::adjustment::AdjustUnsafeFnPointer) => {
453 let adjusted_ty = cx.tcx.expr_ty_adjusted(self);
455 temp_lifetime: temp_lifetime,
458 kind: ExprKind::UnsafeFnPointer { source: expr.to_ref() },
461 Some(&ty::adjustment::AdjustMutToConstPointer) => {
462 let adjusted_ty = cx.tcx.expr_ty_adjusted(self);
464 temp_lifetime: temp_lifetime,
467 kind: ExprKind::Cast { source: expr.to_ref() },
470 Some(&ty::adjustment::AdjustDerefRef(ref adj)) => {
471 for i in 0..adj.autoderefs {
474 expr.ty.adjust_for_autoderef(
479 |mc| cx.tcx.tables.borrow().method_map.get(&mc).map(|m| m.ty));
480 debug!("make_mirror: autoderef #{}, adjusted_ty={:?}", i, adjusted_ty);
481 let method_key = ty::MethodCall::autoderef(self.id, i);
483 cx.tcx.tables.borrow().method_map.get(&method_key).map(|m| m.ty);
484 let kind = if let Some(meth_ty) = meth_ty {
485 debug!("make_mirror: overloaded autoderef (meth_ty={:?})", meth_ty);
487 let ref_ty = cx.tcx.no_late_bound_regions(&meth_ty.fn_ret());
488 let (region, mutbl) = match ref_ty {
489 Some(ty::FnConverging(&ty::TyS {
490 sty: ty::TyRef(region, mt), ..
491 })) => (region, mt.mutbl),
492 _ => cx.tcx.sess.span_bug(
493 expr.span, "autoderef returned bad type")
497 temp_lifetime: temp_lifetime,
499 region, ty::TypeAndMut { ty: expr.ty, mutbl: mutbl }),
501 kind: ExprKind::Borrow {
503 borrow_kind: to_borrow_kind(mutbl),
508 overloaded_lvalue(cx, self, method_key,
509 PassArgs::ByRef, expr.to_ref(), vec![])
511 debug!("make_mirror: built-in autoderef");
512 ExprKind::Deref { arg: expr.to_ref() }
515 temp_lifetime: temp_lifetime,
522 if let Some(autoref) = adj.autoref {
523 let adjusted_ty = expr.ty.adjust_for_autoref(cx.tcx, Some(autoref));
525 ty::adjustment::AutoPtr(r, m) => {
527 temp_lifetime: temp_lifetime,
530 kind: ExprKind::Borrow {
532 borrow_kind: to_borrow_kind(m),
537 ty::adjustment::AutoUnsafe(m) => {
538 // Convert this to a suitable `&foo` and
539 // then an unsafe coercion. Limit the region to be just this
541 let region = ty::ReScope(expr_extent);
542 let region = cx.tcx.mk_region(region);
544 temp_lifetime: temp_lifetime,
545 ty: cx.tcx.mk_ref(region, ty::TypeAndMut { ty: expr.ty, mutbl: m }),
547 kind: ExprKind::Borrow {
549 borrow_kind: to_borrow_kind(m),
554 temp_lifetime: temp_lifetime,
557 kind: ExprKind::Cast { source: expr.to_ref() },
563 if let Some(target) = adj.unsize {
565 temp_lifetime: temp_lifetime,
568 kind: ExprKind::Unsize { source: expr.to_ref() },
574 // Next, wrap this up in the expr's scope.
576 temp_lifetime: temp_lifetime,
579 kind: ExprKind::Scope {
581 value: expr.to_ref(),
585 // Finally, create a destruction scope, if any.
586 if let Some(extent) = cx.tcx.region_maps.opt_destruction_extent(self.id) {
588 temp_lifetime: temp_lifetime,
591 kind: ExprKind::Scope {
593 value: expr.to_ref(),
603 fn method_callee<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>,
605 method_call: ty::MethodCall)
607 let tables = cx.tcx.tables.borrow();
608 let callee = &tables.method_map[&method_call];
609 let temp_lifetime = cx.tcx.region_maps.temporary_scope(expr.id);
611 temp_lifetime: temp_lifetime,
614 kind: ExprKind::Literal {
615 literal: Literal::Item {
616 def_id: callee.def_id,
617 kind: ItemKind::Method,
618 substs: callee.substs,
624 fn to_borrow_kind(m: hir::Mutability) -> BorrowKind {
626 hir::MutMutable => BorrowKind::Mut,
627 hir::MutImmutable => BorrowKind::Shared,
631 fn convert_arm<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
633 let opt_map = if arm.pats.len() == 1 {
637 pat_util::pat_bindings(&cx.tcx.def_map, &arm.pats[0], |_, p_id, _, path| {
638 map.insert(path.node, p_id);
644 patterns: arm.pats.iter().map(|p| cx.refutable_pat(opt_map, p)).collect(),
645 guard: arm.guard.to_ref(),
646 body: arm.body.to_ref(),
650 fn convert_path_expr<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>, expr: &'tcx hir::Expr) -> ExprKind<'tcx> {
651 let substs = cx.tcx.mk_substs(cx.tcx.node_id_item_substs(expr.id).substs);
652 // Otherwise there may be def_map borrow conflicts
653 let def = cx.tcx.def_map.borrow()[&expr.id].full_def();
654 let (def_id, kind) = match def {
655 // A regular function.
656 Def::Fn(def_id) => (def_id, ItemKind::Function),
657 Def::Method(def_id) => (def_id, ItemKind::Method),
658 Def::Struct(def_id) => match cx.tcx.node_id_to_type(expr.id).sty {
659 // A tuple-struct constructor. Should only be reached if not called in the same
661 ty::TyBareFn(..) => (def_id, ItemKind::Function),
662 // A unit struct which is used as a value. We return a completely different ExprKind
663 // here to account for this special case.
664 ty::TyStruct(adt_def, substs) => return ExprKind::Adt {
671 ref sty => panic!("unexpected sty: {:?}", sty)
673 Def::Variant(enum_id, variant_id) => match cx.tcx.node_id_to_type(expr.id).sty {
674 // A variant constructor. Should only be reached if not called in the same
676 ty::TyBareFn(..) => (variant_id, ItemKind::Function),
677 // A unit variant, similar special case to the struct case above.
678 ty::TyEnum(adt_def, substs) => {
679 debug_assert!(adt_def.did == enum_id);
680 let index = adt_def.variant_index_with_id(variant_id);
681 return ExprKind::Adt {
684 variant_index: index,
689 ref sty => panic!("unexpected sty: {:?}", sty)
692 Def::AssociatedConst(def_id) => {
693 if let Some(v) = cx.try_const_eval_literal(expr) {
694 return ExprKind::Literal { literal: v };
696 (def_id, ItemKind::Constant)
700 Def::Static(node_id, _) => return ExprKind::StaticRef {
704 def @ Def::Local(..) |
705 def @ Def::Upvar(..) => return convert_var(cx, expr, def),
708 cx.tcx.sess.span_bug(
710 &format!("def `{:?}` not yet implemented", def)),
713 literal: Literal::Item { def_id: def_id, kind: kind, substs: substs }
717 fn convert_var<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>,
718 expr: &'tcx hir::Expr,
721 let temp_lifetime = cx.tcx.region_maps.temporary_scope(expr.id);
724 Def::Local(_, node_id) => {
730 Def::Upvar(_, id_var, index, closure_expr_id) => {
731 debug!("convert_var(upvar({:?}, {:?}, {:?}))", id_var, index, closure_expr_id);
732 let var_ty = cx.tcx.node_id_to_type(id_var);
734 let body_id = match cx.tcx.map.find(closure_expr_id) {
735 Some(map::NodeExpr(expr)) => {
737 hir::ExprClosure(_, _, ref body) => body.id,
739 cx.tcx.sess.span_bug(expr.span, "closure expr is not a closure expr");
744 cx.tcx.sess.span_bug(expr.span, "ast-map has garbage for closure expr");
748 // FIXME free regions in closures are not right
749 let closure_ty = cx.tcx.node_id_to_type(closure_expr_id);
751 // FIXME we're just hard-coding the idea that the
752 // signature will be &self or &mut self and hence will
753 // have a bound region with number 0
754 let region = ty::Region::ReFree(ty::FreeRegion {
755 scope: cx.tcx.region_maps.node_extent(body_id),
756 bound_region: ty::BoundRegion::BrAnon(0),
758 let region = cx.tcx.mk_region(region);
760 let self_expr = match cx.tcx.closure_kind(cx.tcx.map.local_def_id(closure_expr_id)) {
761 ty::ClosureKind::FnClosureKind => {
763 cx.tcx.mk_ref(region,
764 ty::TypeAndMut { ty: closure_ty,
765 mutbl: hir::MutImmutable });
768 temp_lifetime: temp_lifetime,
770 kind: ExprKind::Deref {
773 temp_lifetime: temp_lifetime,
775 kind: ExprKind::SelfRef
780 ty::ClosureKind::FnMutClosureKind => {
782 cx.tcx.mk_ref(region,
783 ty::TypeAndMut { ty: closure_ty,
784 mutbl: hir::MutMutable });
787 temp_lifetime: temp_lifetime,
789 kind: ExprKind::Deref {
792 temp_lifetime: temp_lifetime,
794 kind: ExprKind::SelfRef
799 ty::ClosureKind::FnOnceClosureKind => {
802 temp_lifetime: temp_lifetime,
804 kind: ExprKind::SelfRef,
809 // at this point we have `self.n`, which loads up the upvar
810 let field_kind = ExprKind::Field {
811 lhs: self_expr.to_ref(),
812 name: Field::new(index),
815 // ...but the upvar might be an `&T` or `&mut T` capture, at which
816 // point we need an implicit deref
817 let upvar_id = ty::UpvarId {
819 closure_expr_id: closure_expr_id,
821 let upvar_capture = match cx.tcx.upvar_capture(upvar_id) {
824 cx.tcx.sess.span_bug(
826 &format!("no upvar_capture for {:?}", upvar_id));
829 match upvar_capture {
830 ty::UpvarCapture::ByValue => field_kind,
831 ty::UpvarCapture::ByRef(borrow) => {
834 temp_lifetime: temp_lifetime,
836 cx.tcx.mk_region(borrow.region),
839 mutbl: borrow.kind.to_mutbl_lossy()
849 _ => cx.tcx.sess.span_bug(expr.span, "type of & not region"),
854 fn bin_op(op: hir::BinOp_) -> BinOp {
856 hir::BinOp_::BiAdd => BinOp::Add,
857 hir::BinOp_::BiSub => BinOp::Sub,
858 hir::BinOp_::BiMul => BinOp::Mul,
859 hir::BinOp_::BiDiv => BinOp::Div,
860 hir::BinOp_::BiRem => BinOp::Rem,
861 hir::BinOp_::BiBitXor => BinOp::BitXor,
862 hir::BinOp_::BiBitAnd => BinOp::BitAnd,
863 hir::BinOp_::BiBitOr => BinOp::BitOr,
864 hir::BinOp_::BiShl => BinOp::Shl,
865 hir::BinOp_::BiShr => BinOp::Shr,
866 hir::BinOp_::BiEq => BinOp::Eq,
867 hir::BinOp_::BiLt => BinOp::Lt,
868 hir::BinOp_::BiLe => BinOp::Le,
869 hir::BinOp_::BiNe => BinOp::Ne,
870 hir::BinOp_::BiGe => BinOp::Ge,
871 hir::BinOp_::BiGt => BinOp::Gt,
872 _ => panic!("no equivalent for ast binop {:?}", op),
881 fn overloaded_operator<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>,
882 expr: &'tcx hir::Expr,
883 method_call: ty::MethodCall,
885 receiver: ExprRef<'tcx>,
886 args: Vec<&'tcx P<hir::Expr>>)
888 // the receiver has all the adjustments that are needed, so we can
889 // just push a reference to it
890 let mut argrefs = vec![receiver];
892 // the arguments, unfortunately, do not, so if this is a ByRef
893 // operator, we have to gin up the autorefs (but by value is easy)
895 PassArgs::ByValue => {
896 argrefs.extend(args.iter().map(|arg| arg.to_ref()))
900 let scope = cx.tcx.region_maps.node_extent(expr.id);
901 let region = cx.tcx.mk_region(ty::ReScope(scope));
902 let temp_lifetime = cx.tcx.region_maps.temporary_scope(expr.id);
906 let arg_ty = cx.tcx.expr_ty_adjusted(arg);
908 cx.tcx.mk_ref(region,
909 ty::TypeAndMut { ty: arg_ty,
910 mutbl: hir::MutImmutable });
912 temp_lifetime: temp_lifetime,
915 kind: ExprKind::Borrow { region: *region,
916 borrow_kind: BorrowKind::Shared,
923 // now create the call itself
924 let fun = method_callee(cx, expr, method_call);
932 fn overloaded_lvalue<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>,
933 expr: &'tcx hir::Expr,
934 method_call: ty::MethodCall,
936 receiver: ExprRef<'tcx>,
937 args: Vec<&'tcx P<hir::Expr>>)
939 // For an overloaded *x or x[y] expression of type T, the method
940 // call returns an &T and we must add the deref so that the types
941 // line up (this is because `*x` and `x[y]` represent lvalues):
943 // to find the type &T of the content returned by the method;
944 let tables = cx.tcx.tables.borrow();
945 let callee = &tables.method_map[&method_call];
946 let ref_ty = callee.ty.fn_ret();
947 let ref_ty = cx.tcx.no_late_bound_regions(&ref_ty).unwrap().unwrap();
949 // (1) callees always have all late-bound regions fully instantiated,
950 // (2) overloaded methods don't return `!`
952 // construct the complete expression `foo()` for the overloaded call,
953 // which will yield the &T type
954 let temp_lifetime = cx.tcx.region_maps.temporary_scope(expr.id);
955 let ref_kind = overloaded_operator(cx, expr, method_call, pass_args, receiver, args);
956 let ref_expr = Expr {
957 temp_lifetime: temp_lifetime,
963 // construct and return a deref wrapper `*foo()`
964 ExprKind::Deref { arg: ref_expr.to_ref() }
967 fn capture_freevar<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>,
968 closure_expr: &'tcx hir::Expr,
969 freevar: &ty::Freevar,
970 freevar_ty: Ty<'tcx>)
972 let id_var = freevar.def.var_id();
973 let upvar_id = ty::UpvarId {
975 closure_expr_id: closure_expr.id,
977 let upvar_capture = cx.tcx.upvar_capture(upvar_id).unwrap();
978 let temp_lifetime = cx.tcx.region_maps.temporary_scope(closure_expr.id);
979 let var_ty = cx.tcx.node_id_to_type(id_var);
980 let captured_var = Expr {
981 temp_lifetime: temp_lifetime,
983 span: closure_expr.span,
984 kind: convert_var(cx, closure_expr, freevar.def),
986 match upvar_capture {
987 ty::UpvarCapture::ByValue => {
988 captured_var.to_ref()
990 ty::UpvarCapture::ByRef(upvar_borrow) => {
991 let borrow_kind = match upvar_borrow.kind {
992 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
993 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
994 ty::BorrowKind::MutBorrow => BorrowKind::Mut,
997 temp_lifetime: temp_lifetime,
999 span: closure_expr.span,
1000 kind: ExprKind::Borrow { region: upvar_borrow.region,
1001 borrow_kind: borrow_kind,
1002 arg: captured_var.to_ref() }
1008 fn loop_label<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>, expr: &'tcx hir::Expr) -> CodeExtent {
1009 match cx.tcx.def_map.borrow().get(&expr.id).map(|d| d.full_def()) {
1010 Some(Def::Label(loop_id)) => cx.tcx.region_maps.node_extent(loop_id),
1012 cx.tcx.sess.span_bug(expr.span, &format!("loop scope resolved to {:?}", d));
1017 /// Converts a list of named fields (i.e. for struct-like struct/enum ADTs) into FieldExprRef.
1018 fn field_refs<'tcx>(variant: VariantDef<'tcx>,
1019 fields: &'tcx [hir::Field])
1020 -> Vec<FieldExprRef<'tcx>>
1023 .map(|field| FieldExprRef {
1024 name: Field::new(variant.index_of_field_named(field.name.node).unwrap()),
1025 expr: field.expr.to_ref(),