1 use crate::hair::cx::block;
2 use crate::hair::cx::to_ref::ToRef;
3 use crate::hair::cx::Cx;
4 use crate::hair::util::UserAnnotatedTyHelpers;
6 use rustc::mir::interpret::{ErrorHandled, Scalar};
7 use rustc::mir::BorrowKind;
8 use rustc::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability, PointerCast};
9 use rustc::ty::subst::{InternalSubsts, SubstsRef};
10 use rustc::ty::{self, AdtKind, Ty};
12 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
13 use rustc_index::vec::Idx;
16 impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr<'tcx> {
17 type Output = Expr<'tcx>;
19 fn make_mirror(self, cx: &mut Cx<'_, 'tcx>) -> Expr<'tcx> {
20 let temp_lifetime = cx.region_scope_tree.temporary_scope(self.hir_id.local_id);
21 let expr_scope = region::Scope { id: self.hir_id.local_id, data: region::ScopeData::Node };
23 debug!("Expr::make_mirror(): id={}, span={:?}", self.hir_id, self.span);
25 let mut expr = make_mirror_unadjusted(cx, self);
27 // Now apply adjustments, if any.
28 for adjustment in cx.tables().expr_adjustments(self) {
29 debug!("make_mirror: expr={:?} applying adjustment={:?}", expr, adjustment);
30 expr = apply_adjustment(cx, self, expr, adjustment);
33 // Next, wrap this up in the expr's scope.
38 kind: ExprKind::Scope {
39 region_scope: expr_scope,
41 lint_level: LintLevel::Explicit(self.hir_id),
45 // Finally, create a destruction scope, if any.
46 if let Some(region_scope) = cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id)
52 kind: ExprKind::Scope {
55 lint_level: LintLevel::Inherited,
65 fn apply_adjustment<'a, 'tcx>(
66 cx: &mut Cx<'a, 'tcx>,
67 hir_expr: &'tcx hir::Expr<'tcx>,
69 adjustment: &Adjustment<'tcx>,
71 let Expr { temp_lifetime, mut span, .. } = expr;
73 // Adjust the span from the block, to the last expression of the
74 // block. This is a better span when returning a mutable reference
75 // with too short a lifetime. The error message will use the span
76 // from the assignment to the return place, which should only point
77 // at the returned value, not the entire function body.
79 // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
81 // // ^ error message points at this expression.
83 let mut adjust_span = |expr: &mut Expr<'tcx>| {
84 if let ExprKind::Block { body } = expr.kind {
85 if let Some(ref last_expr) = body.expr {
86 span = last_expr.span;
92 let kind = match adjustment.kind {
93 Adjust::Pointer(PointerCast::Unsize) => {
94 adjust_span(&mut expr);
95 ExprKind::Pointer { cast: PointerCast::Unsize, source: expr.to_ref() }
97 Adjust::Pointer(cast) => ExprKind::Pointer { cast, source: expr.to_ref() },
98 Adjust::NeverToAny => ExprKind::NeverToAny { source: expr.to_ref() },
99 Adjust::Deref(None) => {
100 adjust_span(&mut expr);
101 ExprKind::Deref { arg: expr.to_ref() }
103 Adjust::Deref(Some(deref)) => {
104 // We don't need to do call adjust_span here since
105 // deref coercions always start with a built-in deref.
106 let call = deref.method_call(cx.tcx(), expr.ty);
110 ty: cx.tcx.mk_ref(deref.region, ty::TypeAndMut { ty: expr.ty, mutbl: deref.mutbl }),
112 kind: ExprKind::Borrow {
113 borrow_kind: deref.mutbl.to_borrow_kind(),
118 overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
120 Adjust::Borrow(AutoBorrow::Ref(_, m)) => {
121 ExprKind::Borrow { borrow_kind: m.to_borrow_kind(), arg: expr.to_ref() }
123 Adjust::Borrow(AutoBorrow::RawPtr(mutability)) => {
124 ExprKind::AddressOf { mutability, arg: expr.to_ref() }
128 Expr { temp_lifetime, ty: adjustment.target, span, kind }
131 fn make_mirror_unadjusted<'a, 'tcx>(
132 cx: &mut Cx<'a, 'tcx>,
133 expr: &'tcx hir::Expr<'tcx>,
135 let expr_ty = cx.tables().expr_ty(expr);
136 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
138 let kind = match expr.kind {
139 // Here comes the interesting stuff:
140 hir::ExprKind::MethodCall(_, method_span, ref args) => {
141 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
142 let expr = method_callee(cx, expr, method_span, None);
143 let args = args.iter().map(|e| e.to_ref()).collect();
144 ExprKind::Call { ty: expr.ty, fun: expr.to_ref(), args, from_hir_call: true }
147 hir::ExprKind::Call(ref fun, ref args) => {
148 if cx.tables().is_method_call(expr) {
149 // The callee is something implementing Fn, FnMut, or FnOnce.
150 // Find the actual method implementation being called and
151 // build the appropriate UFCS call expression with the
152 // callee-object as expr parameter.
154 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
156 let method = method_callee(cx, expr, fun.span, None);
158 let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
159 let tupled_args = Expr {
160 ty: cx.tcx.mk_tup(arg_tys),
163 kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
168 fun: method.to_ref(),
169 args: vec![fun.to_ref(), tupled_args.to_ref()],
174 if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = fun.kind {
175 // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
176 expr_ty.ty_adt_def().and_then(|adt_def| match path.res {
177 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) => {
178 Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id)))
180 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
186 if let Some((adt_def, index)) = adt_data {
187 let substs = cx.tables().node_substs(fun.hir_id);
188 let user_provided_types = cx.tables().user_provided_types();
189 let user_ty = user_provided_types.get(fun.hir_id).copied().map(|mut u_ty| {
190 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
195 debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
197 let field_refs = args
200 .map(|(idx, e)| FieldExprRef { name: Field::new(idx), expr: e.to_ref() })
205 variant_index: index,
212 ty: cx.tables().node_type(fun.hir_id),
221 hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, ref arg) => {
222 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: arg.to_ref() }
225 hir::ExprKind::AddrOf(hir::BorrowKind::Raw, mutability, ref arg) => {
226 ExprKind::AddressOf { mutability, arg: arg.to_ref() }
229 hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
231 hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
232 ExprKind::Assign { lhs: lhs.to_ref(), rhs: rhs.to_ref() }
235 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
236 if cx.tables().is_method_call(expr) {
237 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
239 ExprKind::AssignOp { op: bin_op(op.node), lhs: lhs.to_ref(), rhs: rhs.to_ref() }
243 hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
244 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
248 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
249 if cx.tables().is_method_call(expr) {
250 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
253 match (op.node, cx.constness) {
254 // Destroy control flow if `#![feature(const_if_match)]` is not enabled.
255 (hir::BinOpKind::And, hir::Constness::Const)
256 if !cx.tcx.features().const_if_match =>
258 cx.control_flow_destroyed.push((op.span, "`&&` operator".into()));
259 ExprKind::Binary { op: BinOp::BitAnd, lhs: lhs.to_ref(), rhs: rhs.to_ref() }
261 (hir::BinOpKind::Or, hir::Constness::Const)
262 if !cx.tcx.features().const_if_match =>
264 cx.control_flow_destroyed.push((op.span, "`||` operator".into()));
265 ExprKind::Binary { op: BinOp::BitOr, lhs: lhs.to_ref(), rhs: rhs.to_ref() }
268 (hir::BinOpKind::And, _) => ExprKind::LogicalOp {
273 (hir::BinOpKind::Or, _) => ExprKind::LogicalOp {
280 let op = bin_op(op.node);
281 ExprKind::Binary { op, lhs: lhs.to_ref(), rhs: rhs.to_ref() }
287 hir::ExprKind::Index(ref lhs, ref index) => {
288 if cx.tables().is_method_call(expr) {
289 overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
291 ExprKind::Index { lhs: lhs.to_ref(), index: index.to_ref() }
295 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
296 if cx.tables().is_method_call(expr) {
297 overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
299 ExprKind::Deref { arg: arg.to_ref() }
303 hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
304 if cx.tables().is_method_call(expr) {
305 overloaded_operator(cx, expr, vec![arg.to_ref()])
307 ExprKind::Unary { op: UnOp::Not, arg: arg.to_ref() }
311 hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
312 if cx.tables().is_method_call(expr) {
313 overloaded_operator(cx, expr, vec![arg.to_ref()])
315 if let hir::ExprKind::Lit(ref lit) = arg.kind {
317 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
321 ExprKind::Unary { op: UnOp::Neg, arg: arg.to_ref() }
326 hir::ExprKind::Struct(ref qpath, ref fields, ref base) => match expr_ty.kind {
327 ty::Adt(adt, substs) => match adt.adt_kind() {
328 AdtKind::Struct | AdtKind::Union => {
329 let user_provided_types = cx.tables().user_provided_types();
330 let user_ty = user_provided_types.get(expr.hir_id).copied();
331 debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
334 variant_index: VariantIdx::new(0),
337 fields: field_refs(cx, fields),
338 base: base.as_ref().map(|base| FruInfo {
340 field_types: cx.tables().fru_field_types()[expr.hir_id].clone(),
345 let res = cx.tables().qpath_res(qpath, expr.hir_id);
347 Res::Def(DefKind::Variant, variant_id) => {
348 assert!(base.is_none());
350 let index = adt.variant_index_with_id(variant_id);
351 let user_provided_types = cx.tables().user_provided_types();
352 let user_ty = user_provided_types.get(expr.hir_id).copied();
353 debug!("make_mirror_unadjusted: (variant) user_ty={:?}", user_ty);
356 variant_index: index,
359 fields: field_refs(cx, fields),
364 span_bug!(expr.span, "unexpected res: {:?}", res);
370 span_bug!(expr.span, "unexpected type for struct literal: {:?}", expr_ty);
374 hir::ExprKind::Closure(..) => {
375 let closure_ty = cx.tables().expr_ty(expr);
376 let (def_id, substs, movability) = match closure_ty.kind {
377 ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
378 ty::Generator(def_id, substs, movability) => {
379 (def_id, UpvarSubsts::Generator(substs), Some(movability))
382 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
389 .flat_map(|upvars| upvars.iter())
390 .zip(substs.upvar_tys(def_id, cx.tcx))
391 .map(|((&var_hir_id, _), ty)| capture_upvar(cx, expr, var_hir_id, ty))
393 ExprKind::Closure { closure_id: def_id, substs, upvars, movability }
396 hir::ExprKind::Path(ref qpath) => {
397 let res = cx.tables().qpath_res(qpath, expr.hir_id);
398 convert_path_expr(cx, expr, res)
401 hir::ExprKind::InlineAsm(ref asm) => ExprKind::InlineAsm {
403 outputs: asm.outputs_exprs.to_ref(),
404 inputs: asm.inputs_exprs.to_ref(),
407 // Now comes the rote stuff:
408 hir::ExprKind::Repeat(ref v, ref count) => {
409 let def_id = cx.tcx.hir().local_def_id(count.hir_id);
410 let substs = InternalSubsts::identity_for_item(cx.tcx, def_id);
411 let span = cx.tcx.def_span(def_id);
412 let count = match cx.tcx.const_eval_resolve(
413 ty::ParamEnv::reveal_all(),
420 if let Some(count) = cv.try_to_bits_for_ty(
422 ty::ParamEnv::reveal_all(),
427 bug!("repeat count constant value can't be converted to usize");
430 Err(ErrorHandled::Reported) => 0,
431 Err(ErrorHandled::TooGeneric) => {
432 let span = cx.tcx.def_span(def_id);
433 cx.tcx.sess.span_err(span, "array lengths can't depend on generic parameters");
438 ExprKind::Repeat { value: v.to_ref(), count }
440 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
441 hir::ExprKind::Break(dest, ref value) => match dest.target_id {
442 Ok(target_id) => ExprKind::Break {
443 label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node },
444 value: value.to_ref(),
446 Err(err) => bug!("invalid loop id for break: {}", err),
448 hir::ExprKind::Continue(dest) => match dest.target_id {
449 Ok(loop_id) => ExprKind::Continue {
450 label: region::Scope { id: loop_id.local_id, data: region::ScopeData::Node },
452 Err(err) => bug!("invalid loop id for continue: {}", err),
454 hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
455 scrutinee: discr.to_ref(),
456 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
458 hir::ExprKind::Loop(ref body, _, _) => {
459 ExprKind::Loop { body: block::to_expr_ref(cx, body) }
461 hir::ExprKind::Field(ref source, ..) => ExprKind::Field {
462 lhs: source.to_ref(),
463 name: Field::new(cx.tcx.field_index(expr.hir_id, cx.tables)),
465 hir::ExprKind::Cast(ref source, ref cast_ty) => {
466 // Check for a user-given type annotation on this `cast`
467 let user_provided_types = cx.tables.user_provided_types();
468 let user_ty = user_provided_types.get(cast_ty.hir_id);
471 "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
472 expr, cast_ty.hir_id, user_ty,
475 // Check to see if this cast is a "coercion cast", where the cast is actually done
476 // using a coercion (or is a no-op).
477 let cast = if cx.tables().is_coercion_cast(source.hir_id) {
478 // Convert the lexpr to a vexpr.
479 ExprKind::Use { source: source.to_ref() }
480 } else if cx.tables().expr_ty(source).is_region_ptr() {
481 // Special cased so that we can type check that the element
482 // type of the source matches the pointed to type of the
484 ExprKind::Pointer { source: source.to_ref(), cast: PointerCast::ArrayToPointer }
486 // check whether this is casting an enum variant discriminant
487 // to prevent cycles, we refer to the discriminant initializer
488 // which is always an integer and thus doesn't need to know the
489 // enum's layout (or its tag type) to compute it during const eval
493 // B = A as isize + 4,
495 // The correct solution would be to add symbolic computations to miri,
496 // so we wouldn't have to compute and store the actual value
497 let var = if let hir::ExprKind::Path(ref qpath) = source.kind {
498 let res = cx.tables().qpath_res(qpath, source.hir_id);
499 cx.tables().node_type(source.hir_id).ty_adt_def().and_then(
500 |adt_def| match res {
502 DefKind::Ctor(CtorOf::Variant, CtorKind::Const),
505 let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
506 let (d, o) = adt_def.discriminant_def_for_variant(idx);
507 use rustc::ty::util::IntTypeExt;
508 let ty = adt_def.repr.discr_type();
509 let ty = ty.to_ty(cx.tcx());
519 let source = if let Some((did, offset, var_ty)) = var {
520 let mk_const = |literal| {
525 kind: ExprKind::Literal { literal, user_ty: None },
529 let offset = mk_const(ty::Const::from_bits(
532 cx.param_env.and(var_ty),
536 // in case we are offsetting from a computed discriminant
537 // and not the beginning of discriminants (which is always `0`)
538 let substs = InternalSubsts::identity_for_item(cx.tcx(), did);
539 let lhs = mk_const(cx.tcx().mk_const(ty::Const {
540 val: ty::ConstKind::Unevaluated(did, substs, None),
543 let bin = ExprKind::Binary { op: BinOp::Add, lhs, rhs: offset };
544 Expr { temp_lifetime, ty: var_ty, span: expr.span, kind: bin }.to_ref()
552 ExprKind::Cast { source }
555 if let Some(user_ty) = user_ty {
556 // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
557 // inefficient, revisit this when performance becomes an issue.
558 let cast_expr = Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind: cast };
559 debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
561 ExprKind::ValueTypeAscription {
562 source: cast_expr.to_ref(),
563 user_ty: Some(*user_ty),
569 hir::ExprKind::Type(ref source, ref ty) => {
570 let user_provided_types = cx.tables.user_provided_types();
571 let user_ty = user_provided_types.get(ty.hir_id).copied();
572 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
573 if source.is_syntactic_place_expr() {
574 ExprKind::PlaceTypeAscription { source: source.to_ref(), user_ty }
576 ExprKind::ValueTypeAscription { source: source.to_ref(), user_ty }
579 hir::ExprKind::DropTemps(ref source) => ExprKind::Use { source: source.to_ref() },
580 hir::ExprKind::Box(ref value) => ExprKind::Box { value: value.to_ref() },
581 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
582 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
584 hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: v.to_ref() },
585 hir::ExprKind::Err => unreachable!(),
588 Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
591 fn user_substs_applied_to_res<'tcx>(
592 cx: &mut Cx<'_, 'tcx>,
595 ) -> Option<ty::CanonicalUserType<'tcx>> {
596 debug!("user_substs_applied_to_res: res={:?}", res);
597 let user_provided_type = match res {
598 // A reference to something callable -- e.g., a fn, method, or
599 // a tuple-struct or tuple-variant. This has the type of a
600 // `Fn` but with the user-given substitutions.
601 Res::Def(DefKind::Fn, _)
602 | Res::Def(DefKind::AssocFn, _)
603 | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
604 | Res::Def(DefKind::Const, _)
605 | Res::Def(DefKind::AssocConst, _) => {
606 cx.tables().user_provided_types().get(hir_id).copied()
609 // A unit struct/variant which is used as a value (e.g.,
610 // `None`). This has the type of the enum/struct that defines
611 // this variant -- but with the substitutions given by the
613 Res::Def(DefKind::Ctor(_, CtorKind::Const), _) => {
614 cx.user_substs_applied_to_ty_of_hir_id(hir_id)
617 // `Self` is used in expression as a tuple struct constructor or an unit struct constructor
618 Res::SelfCtor(_) => cx.user_substs_applied_to_ty_of_hir_id(hir_id),
620 _ => bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id),
622 debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
626 fn method_callee<'a, 'tcx>(
627 cx: &mut Cx<'a, 'tcx>,
628 expr: &hir::Expr<'_>,
630 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
632 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
633 let (def_id, substs, user_ty) = match overloaded_callee {
634 Some((def_id, substs)) => (def_id, substs, None),
636 let (kind, def_id) = cx
638 .type_dependent_def(expr.hir_id)
639 .unwrap_or_else(|| span_bug!(expr.span, "no type-dependent def for method callee"));
640 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, Res::Def(kind, def_id));
641 debug!("method_callee: user_ty={:?}", user_ty);
642 (def_id, cx.tables().node_substs(expr.hir_id), user_ty)
645 let ty = cx.tcx().mk_fn_def(def_id, substs);
650 kind: ExprKind::Literal { literal: ty::Const::zero_sized(cx.tcx(), ty), user_ty },
655 fn to_borrow_kind(&self) -> BorrowKind;
658 impl ToBorrowKind for AutoBorrowMutability {
659 fn to_borrow_kind(&self) -> BorrowKind {
660 use rustc::ty::adjustment::AllowTwoPhase;
662 AutoBorrowMutability::Mut { allow_two_phase_borrow } => BorrowKind::Mut {
663 allow_two_phase_borrow: match allow_two_phase_borrow {
664 AllowTwoPhase::Yes => true,
665 AllowTwoPhase::No => false,
668 AutoBorrowMutability::Not => BorrowKind::Shared,
673 impl ToBorrowKind for hir::Mutability {
674 fn to_borrow_kind(&self) -> BorrowKind {
676 hir::Mutability::Mut => BorrowKind::Mut { allow_two_phase_borrow: false },
677 hir::Mutability::Not => BorrowKind::Shared,
682 fn convert_arm<'tcx>(cx: &mut Cx<'_, 'tcx>, arm: &'tcx hir::Arm<'tcx>) -> Arm<'tcx> {
684 pattern: cx.pattern_from_hir(&arm.pat),
685 guard: match arm.guard {
686 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
689 body: arm.body.to_ref(),
690 lint_level: LintLevel::Explicit(arm.hir_id),
691 scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
696 fn convert_path_expr<'a, 'tcx>(
697 cx: &mut Cx<'a, 'tcx>,
698 expr: &'tcx hir::Expr<'tcx>,
700 ) -> ExprKind<'tcx> {
701 let substs = cx.tables().node_substs(expr.hir_id);
703 // A regular function, constructor function or a constant.
704 Res::Def(DefKind::Fn, _)
705 | Res::Def(DefKind::AssocFn, _)
706 | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
707 | Res::SelfCtor(..) => {
708 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
709 debug!("convert_path_expr: user_ty={:?}", user_ty);
711 literal: ty::Const::zero_sized(cx.tcx, cx.tables().node_type(expr.hir_id)),
716 Res::Def(DefKind::ConstParam, def_id) => {
717 let hir_id = cx.tcx.hir().as_local_hir_id(def_id).unwrap();
718 let item_id = cx.tcx.hir().get_parent_node(hir_id);
719 let item_def_id = cx.tcx.hir().local_def_id(item_id);
720 let generics = cx.tcx.generics_of(item_def_id);
721 let local_def_id = cx.tcx.hir().local_def_id(hir_id);
722 let index = generics.param_def_id_to_index[&local_def_id];
723 let name = cx.tcx.hir().name(hir_id);
724 let val = ty::ConstKind::Param(ty::ParamConst::new(index, name));
726 literal: cx.tcx.mk_const(ty::Const { val, ty: cx.tables().node_type(expr.hir_id) }),
731 Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => {
732 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
733 debug!("convert_path_expr: (const) user_ty={:?}", user_ty);
735 literal: cx.tcx.mk_const(ty::Const {
736 val: ty::ConstKind::Unevaluated(def_id, substs, None),
737 ty: cx.tables().node_type(expr.hir_id),
743 Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
744 let user_provided_types = cx.tables.user_provided_types();
745 let user_provided_type = user_provided_types.get(expr.hir_id).copied();
746 debug!("convert_path_expr: user_provided_type={:?}", user_provided_type);
747 let ty = cx.tables().node_type(expr.hir_id);
749 // A unit struct/variant which is used as a value.
750 // We return a completely different ExprKind here to account for this special case.
751 ty::Adt(adt_def, substs) => ExprKind::Adt {
753 variant_index: adt_def.variant_index_with_ctor_id(def_id),
755 user_ty: user_provided_type,
759 _ => bug!("unexpected ty: {:?}", ty),
763 // We encode uses of statics as a `*&STATIC` where the `&STATIC` part is
764 // a constant reference (or constant raw pointer for `static mut`) in MIR
765 Res::Def(DefKind::Static, id) => {
766 let ty = cx.tcx.static_ptr_ty(id);
767 let ptr = cx.tcx.alloc_map.lock().create_static_alloc(id);
768 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
774 kind: ExprKind::StaticRef {
775 literal: ty::Const::from_scalar(cx.tcx, Scalar::Ptr(ptr.into()), ty),
783 Res::Local(var_hir_id) => convert_var(cx, expr, var_hir_id),
785 _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
789 fn convert_var<'tcx>(
790 cx: &mut Cx<'_, 'tcx>,
791 expr: &'tcx hir::Expr<'tcx>,
792 var_hir_id: hir::HirId,
793 ) -> ExprKind<'tcx> {
798 .and_then(|upvars| upvars.get_full(&var_hir_id).map(|(i, _, _)| i));
801 "convert_var({:?}): upvar_index={:?}, body_owner={:?}",
802 var_hir_id, upvar_index, cx.body_owner
805 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
808 None => ExprKind::VarRef { id: var_hir_id },
810 Some(upvar_index) => {
811 let closure_def_id = cx.body_owner;
812 let upvar_id = ty::UpvarId {
813 var_path: ty::UpvarPath { hir_id: var_hir_id },
814 closure_expr_id: closure_def_id.expect_local(),
816 let var_ty = cx.tables().node_type(var_hir_id);
818 // FIXME free regions in closures are not right
821 .node_type(cx.tcx.hir().local_def_id_to_hir_id(upvar_id.closure_expr_id));
823 // FIXME we're just hard-coding the idea that the
824 // signature will be &self or &mut self and hence will
825 // have a bound region with number 0
826 let region = ty::ReFree(ty::FreeRegion {
827 scope: closure_def_id,
828 bound_region: ty::BoundRegion::BrAnon(0),
830 let region = cx.tcx.mk_region(region);
832 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.kind {
833 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
834 ty::ClosureKind::Fn => {
835 let ref_closure_ty = cx.tcx.mk_ref(
837 ty::TypeAndMut { ty: closure_ty, mutbl: hir::Mutability::Not },
843 kind: ExprKind::Deref {
848 kind: ExprKind::SelfRef,
854 ty::ClosureKind::FnMut => {
855 let ref_closure_ty = cx.tcx.mk_ref(
857 ty::TypeAndMut { ty: closure_ty, mutbl: hir::Mutability::Mut },
863 kind: ExprKind::Deref {
868 kind: ExprKind::SelfRef,
874 ty::ClosureKind::FnOnce => Expr {
878 kind: ExprKind::SelfRef,
882 Expr { ty: closure_ty, temp_lifetime, span: expr.span, kind: ExprKind::SelfRef }
885 // at this point we have `self.n`, which loads up the upvar
887 ExprKind::Field { lhs: self_expr.to_ref(), name: Field::new(upvar_index) };
889 // ...but the upvar might be an `&T` or `&mut T` capture, at which
890 // point we need an implicit deref
891 match cx.tables().upvar_capture(upvar_id) {
892 ty::UpvarCapture::ByValue => field_kind,
893 ty::UpvarCapture::ByRef(borrow) => ExprKind::Deref {
898 ty::TypeAndMut { ty: var_ty, mutbl: borrow.kind.to_mutbl_lossy() },
910 fn bin_op(op: hir::BinOpKind) -> BinOp {
912 hir::BinOpKind::Add => BinOp::Add,
913 hir::BinOpKind::Sub => BinOp::Sub,
914 hir::BinOpKind::Mul => BinOp::Mul,
915 hir::BinOpKind::Div => BinOp::Div,
916 hir::BinOpKind::Rem => BinOp::Rem,
917 hir::BinOpKind::BitXor => BinOp::BitXor,
918 hir::BinOpKind::BitAnd => BinOp::BitAnd,
919 hir::BinOpKind::BitOr => BinOp::BitOr,
920 hir::BinOpKind::Shl => BinOp::Shl,
921 hir::BinOpKind::Shr => BinOp::Shr,
922 hir::BinOpKind::Eq => BinOp::Eq,
923 hir::BinOpKind::Lt => BinOp::Lt,
924 hir::BinOpKind::Le => BinOp::Le,
925 hir::BinOpKind::Ne => BinOp::Ne,
926 hir::BinOpKind::Ge => BinOp::Ge,
927 hir::BinOpKind::Gt => BinOp::Gt,
928 _ => bug!("no equivalent for ast binop {:?}", op),
932 fn overloaded_operator<'a, 'tcx>(
933 cx: &mut Cx<'a, 'tcx>,
934 expr: &'tcx hir::Expr<'tcx>,
935 args: Vec<ExprRef<'tcx>>,
936 ) -> ExprKind<'tcx> {
937 let fun = method_callee(cx, expr, expr.span, None);
938 ExprKind::Call { ty: fun.ty, fun: fun.to_ref(), args, from_hir_call: false }
941 fn overloaded_place<'a, 'tcx>(
942 cx: &mut Cx<'a, 'tcx>,
943 expr: &'tcx hir::Expr<'tcx>,
945 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
946 args: Vec<ExprRef<'tcx>>,
947 ) -> ExprKind<'tcx> {
948 // For an overloaded *x or x[y] expression of type T, the method
949 // call returns an &T and we must add the deref so that the types
950 // line up (this is because `*x` and `x[y]` represent places):
952 let recv_ty = match args[0] {
953 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
954 ExprRef::Mirror(ref e) => e.ty,
957 // Reconstruct the output assuming it's a reference with the
958 // same region and mutability as the receiver. This holds for
959 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
960 let (region, mutbl) = match recv_ty.kind {
961 ty::Ref(region, _, mutbl) => (region, mutbl),
962 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
964 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut { ty: place_ty, mutbl });
966 // construct the complete expression `foo()` for the overloaded call,
967 // which will yield the &T type
968 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
969 let fun = method_callee(cx, expr, expr.span, overloaded_callee);
970 let ref_expr = Expr {
974 kind: ExprKind::Call { ty: fun.ty, fun: fun.to_ref(), args, from_hir_call: false },
977 // construct and return a deref wrapper `*foo()`
978 ExprKind::Deref { arg: ref_expr.to_ref() }
981 fn capture_upvar<'tcx>(
982 cx: &mut Cx<'_, 'tcx>,
983 closure_expr: &'tcx hir::Expr<'tcx>,
984 var_hir_id: hir::HirId,
987 let upvar_id = ty::UpvarId {
988 var_path: ty::UpvarPath { hir_id: var_hir_id },
989 closure_expr_id: cx.tcx.hir().local_def_id(closure_expr.hir_id).expect_local(),
991 let upvar_capture = cx.tables().upvar_capture(upvar_id);
992 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
993 let var_ty = cx.tables().node_type(var_hir_id);
994 let captured_var = Expr {
997 span: closure_expr.span,
998 kind: convert_var(cx, closure_expr, var_hir_id),
1000 match upvar_capture {
1001 ty::UpvarCapture::ByValue => captured_var.to_ref(),
1002 ty::UpvarCapture::ByRef(upvar_borrow) => {
1003 let borrow_kind = match upvar_borrow.kind {
1004 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1005 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1006 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false },
1011 span: closure_expr.span,
1012 kind: ExprKind::Borrow { borrow_kind, arg: captured_var.to_ref() },
1019 /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExprRef.
1020 fn field_refs<'a, 'tcx>(
1021 cx: &mut Cx<'a, 'tcx>,
1022 fields: &'tcx [hir::Field<'tcx>],
1023 ) -> Vec<FieldExprRef<'tcx>> {
1026 .map(|field| FieldExprRef {
1027 name: Field::new(cx.tcx.field_index(field.hir_id, cx.tables)),
1028 expr: field.expr.to_ref(),