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;
7 use rustc::hir::def::{CtorKind, CtorOf, DefKind, Res};
8 use rustc::hir::def_id::LocalDefId;
9 use rustc::mir::interpret::{ErrorHandled, Scalar};
10 use rustc::mir::BorrowKind;
11 use rustc::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability, PointerCast};
12 use rustc::ty::subst::{InternalSubsts, SubstsRef};
13 use rustc::ty::{self, AdtKind, Ty};
14 use rustc_index::vec::Idx;
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 { id: self.hir_id.local_id, data: region::ScopeData::Node };
24 debug!("Expr::make_mirror(): id={}, span={:?}", self.hir_id, self.span);
26 let mut expr = make_mirror_unadjusted(cx, self);
28 // Now apply adjustments, if any.
29 for adjustment in cx.tables().expr_adjustments(self) {
30 debug!("make_mirror: expr={:?} applying adjustment={:?}", expr, adjustment);
31 expr = apply_adjustment(cx, self, expr, adjustment);
34 // Next, wrap this up in the expr's scope.
39 kind: ExprKind::Scope {
40 region_scope: expr_scope,
42 lint_level: LintLevel::Explicit(self.hir_id),
46 // Finally, create a destruction scope, if any.
47 if let Some(region_scope) = cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id)
53 kind: ExprKind::Scope {
56 lint_level: LintLevel::Inherited,
66 fn apply_adjustment<'a, 'tcx>(
67 cx: &mut Cx<'a, 'tcx>,
68 hir_expr: &'tcx hir::Expr,
70 adjustment: &Adjustment<'tcx>,
72 let Expr { temp_lifetime, mut span, .. } = expr;
74 // Adjust the span from the block, to the last expression of the
75 // block. This is a better span when returning a mutable reference
76 // with too short a lifetime. The error message will use the span
77 // from the assignment to the return place, which should only point
78 // at the returned value, not the entire function body.
80 // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
82 // // ^ error message points at this expression.
84 let mut adjust_span = |expr: &mut Expr<'tcx>| {
85 if let ExprKind::Block { body } = expr.kind {
86 if let Some(ref last_expr) = body.expr {
87 span = last_expr.span;
93 let kind = match adjustment.kind {
94 Adjust::Pointer(PointerCast::Unsize) => {
95 adjust_span(&mut expr);
96 ExprKind::Pointer { cast: PointerCast::Unsize, source: expr.to_ref() }
98 Adjust::Pointer(cast) => ExprKind::Pointer { cast, source: expr.to_ref() },
99 Adjust::NeverToAny => ExprKind::NeverToAny { source: expr.to_ref() },
100 Adjust::Deref(None) => {
101 adjust_span(&mut expr);
102 ExprKind::Deref { arg: expr.to_ref() }
104 Adjust::Deref(Some(deref)) => {
105 // We don't need to do call adjust_span here since
106 // deref coercions always start with a built-in deref.
107 let call = deref.method_call(cx.tcx(), expr.ty);
111 ty: cx.tcx.mk_ref(deref.region, ty::TypeAndMut { ty: expr.ty, mutbl: deref.mutbl }),
113 kind: ExprKind::Borrow {
114 borrow_kind: deref.mutbl.to_borrow_kind(),
119 overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
121 Adjust::Borrow(AutoBorrow::Ref(_, m)) => {
122 ExprKind::Borrow { borrow_kind: m.to_borrow_kind(), arg: expr.to_ref() }
124 Adjust::Borrow(AutoBorrow::RawPtr(mutability)) => {
125 ExprKind::AddressOf { mutability, arg: expr.to_ref() }
129 Expr { temp_lifetime, ty: adjustment.target, span, kind }
132 fn make_mirror_unadjusted<'a, 'tcx>(cx: &mut Cx<'a, 'tcx>, expr: &'tcx hir::Expr) -> Expr<'tcx> {
133 let expr_ty = cx.tables().expr_ty(expr);
134 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
136 let kind = match expr.kind {
137 // Here comes the interesting stuff:
138 hir::ExprKind::MethodCall(_, method_span, ref args) => {
139 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
140 let expr = method_callee(cx, expr, method_span, None);
141 let args = args.iter().map(|e| e.to_ref()).collect();
142 ExprKind::Call { ty: expr.ty, fun: expr.to_ref(), args, from_hir_call: true }
145 hir::ExprKind::Call(ref fun, ref args) => {
146 if cx.tables().is_method_call(expr) {
147 // The callee is something implementing Fn, FnMut, or FnOnce.
148 // Find the actual method implementation being called and
149 // build the appropriate UFCS call expression with the
150 // callee-object as expr parameter.
152 // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
154 let method = method_callee(cx, expr, fun.span, None);
156 let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
157 let tupled_args = Expr {
158 ty: cx.tcx.mk_tup(arg_tys),
161 kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
166 fun: method.to_ref(),
167 args: vec![fun.to_ref(), tupled_args.to_ref()],
172 if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = fun.kind {
173 // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
174 expr_ty.ty_adt_def().and_then(|adt_def| match path.res {
175 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) => {
176 Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id)))
178 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
184 if let Some((adt_def, index)) = adt_data {
185 let substs = cx.tables().node_substs(fun.hir_id);
186 let user_provided_types = cx.tables().user_provided_types();
188 user_provided_types.get(fun.hir_id).map(|u_ty| *u_ty).map(|mut u_ty| {
189 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
194 debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
196 let field_refs = args
199 .map(|(idx, e)| FieldExprRef { name: Field::new(idx), expr: e.to_ref() })
204 variant_index: index,
211 ty: cx.tables().node_type(fun.hir_id),
220 hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, ref arg) => {
221 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: arg.to_ref() }
224 hir::ExprKind::AddrOf(hir::BorrowKind::Raw, mutability, ref arg) => {
225 ExprKind::AddressOf { mutability, arg: arg.to_ref() }
228 hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
230 hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
231 ExprKind::Assign { lhs: lhs.to_ref(), rhs: rhs.to_ref() }
234 hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
235 if cx.tables().is_method_call(expr) {
236 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
238 ExprKind::AssignOp { op: bin_op(op.node), lhs: lhs.to_ref(), rhs: rhs.to_ref() }
242 hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
243 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
247 hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
248 if cx.tables().is_method_call(expr) {
249 overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
252 match (op.node, cx.constness) {
253 // Destroy control flow if `#![feature(const_if_match)]` is not enabled.
254 (hir::BinOpKind::And, hir::Constness::Const)
255 if !cx.tcx.features().const_if_match =>
257 cx.control_flow_destroyed.push((op.span, "`&&` operator".into()));
258 ExprKind::Binary { op: BinOp::BitAnd, lhs: lhs.to_ref(), rhs: rhs.to_ref() }
260 (hir::BinOpKind::Or, hir::Constness::Const)
261 if !cx.tcx.features().const_if_match =>
263 cx.control_flow_destroyed.push((op.span, "`||` operator".into()));
264 ExprKind::Binary { op: BinOp::BitOr, lhs: lhs.to_ref(), rhs: rhs.to_ref() }
267 (hir::BinOpKind::And, _) => ExprKind::LogicalOp {
272 (hir::BinOpKind::Or, _) => ExprKind::LogicalOp {
279 let op = bin_op(op.node);
280 ExprKind::Binary { op, lhs: lhs.to_ref(), rhs: rhs.to_ref() }
286 hir::ExprKind::Index(ref lhs, ref index) => {
287 if cx.tables().is_method_call(expr) {
288 overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
290 ExprKind::Index { lhs: lhs.to_ref(), index: index.to_ref() }
294 hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
295 if cx.tables().is_method_call(expr) {
296 overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
298 ExprKind::Deref { arg: arg.to_ref() }
302 hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
303 if cx.tables().is_method_call(expr) {
304 overloaded_operator(cx, expr, vec![arg.to_ref()])
306 ExprKind::Unary { op: UnOp::Not, arg: arg.to_ref() }
310 hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
311 if cx.tables().is_method_call(expr) {
312 overloaded_operator(cx, expr, vec![arg.to_ref()])
314 if let hir::ExprKind::Lit(ref lit) = arg.kind {
316 literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
320 ExprKind::Unary { op: UnOp::Neg, arg: arg.to_ref() }
325 hir::ExprKind::Struct(ref qpath, ref fields, ref base) => match expr_ty.kind {
326 ty::Adt(adt, substs) => match adt.adt_kind() {
327 AdtKind::Struct | AdtKind::Union => {
328 let user_provided_types = cx.tables().user_provided_types();
329 let user_ty = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
330 debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
333 variant_index: VariantIdx::new(0),
336 fields: field_refs(cx, fields),
337 base: base.as_ref().map(|base| FruInfo {
339 field_types: cx.tables().fru_field_types()[expr.hir_id].clone(),
344 let res = cx.tables().qpath_res(qpath, expr.hir_id);
346 Res::Def(DefKind::Variant, variant_id) => {
347 assert!(base.is_none());
349 let index = adt.variant_index_with_id(variant_id);
350 let user_provided_types = cx.tables().user_provided_types();
351 let user_ty = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
352 debug!("make_mirror_unadjusted: (variant) user_ty={:?}", user_ty);
355 variant_index: index,
358 fields: field_refs(cx, fields),
363 span_bug!(expr.span, "unexpected res: {:?}", res);
369 span_bug!(expr.span, "unexpected type for struct literal: {:?}", expr_ty);
373 hir::ExprKind::Closure(..) => {
374 let closure_ty = cx.tables().expr_ty(expr);
375 let (def_id, substs, movability) = match closure_ty.kind {
376 ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
377 ty::Generator(def_id, substs, movability) => {
378 (def_id, UpvarSubsts::Generator(substs), Some(movability))
381 span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
388 .flat_map(|upvars| upvars.iter())
389 .zip(substs.upvar_tys(def_id, cx.tcx))
390 .map(|((&var_hir_id, _), ty)| capture_upvar(cx, expr, var_hir_id, ty))
392 ExprKind::Closure { closure_id: def_id, substs, upvars, movability }
395 hir::ExprKind::Path(ref qpath) => {
396 let res = cx.tables().qpath_res(qpath, expr.hir_id);
397 convert_path_expr(cx, expr, res)
400 hir::ExprKind::InlineAsm(ref asm) => ExprKind::InlineAsm {
402 outputs: asm.outputs_exprs.to_ref(),
403 inputs: asm.inputs_exprs.to_ref(),
406 // Now comes the rote stuff:
407 hir::ExprKind::Repeat(ref v, ref count) => {
408 let def_id = cx.tcx.hir().local_def_id(count.hir_id);
409 let substs = InternalSubsts::identity_for_item(cx.tcx, def_id);
410 let span = cx.tcx.def_span(def_id);
411 let count = match cx.tcx.const_eval_resolve(cx.param_env, def_id, substs, Some(span)) {
412 Ok(cv) => cv.eval_usize(cx.tcx, cx.param_env),
413 Err(ErrorHandled::Reported) => 0,
414 Err(ErrorHandled::TooGeneric) => {
415 let span = cx.tcx.def_span(def_id);
416 cx.tcx.sess.span_err(span, "array lengths can't depend on generic parameters");
421 ExprKind::Repeat { value: v.to_ref(), count }
423 hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
424 hir::ExprKind::Break(dest, ref value) => match dest.target_id {
425 Ok(target_id) => ExprKind::Break {
426 label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node },
427 value: value.to_ref(),
429 Err(err) => bug!("invalid loop id for break: {}", err),
431 hir::ExprKind::Continue(dest) => match dest.target_id {
432 Ok(loop_id) => ExprKind::Continue {
433 label: region::Scope { id: loop_id.local_id, data: region::ScopeData::Node },
435 Err(err) => bug!("invalid loop id for continue: {}", err),
437 hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
438 scrutinee: discr.to_ref(),
439 arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
441 hir::ExprKind::Loop(ref body, _, _) => {
442 ExprKind::Loop { body: block::to_expr_ref(cx, body) }
444 hir::ExprKind::Field(ref source, ..) => ExprKind::Field {
445 lhs: source.to_ref(),
446 name: Field::new(cx.tcx.field_index(expr.hir_id, cx.tables)),
448 hir::ExprKind::Cast(ref source, ref cast_ty) => {
449 // Check for a user-given type annotation on this `cast`
450 let user_provided_types = cx.tables.user_provided_types();
451 let user_ty = user_provided_types.get(cast_ty.hir_id);
454 "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
455 expr, cast_ty.hir_id, user_ty,
458 // Check to see if this cast is a "coercion cast", where the cast is actually done
459 // using a coercion (or is a no-op).
460 let cast = if cx.tables().is_coercion_cast(source.hir_id) {
461 // Convert the lexpr to a vexpr.
462 ExprKind::Use { source: source.to_ref() }
463 } else if cx.tables().expr_ty(source).is_region_ptr() {
464 // Special cased so that we can type check that the element
465 // type of the source matches the pointed to type of the
467 ExprKind::Pointer { source: source.to_ref(), cast: PointerCast::ArrayToPointer }
469 // check whether this is casting an enum variant discriminant
470 // to prevent cycles, we refer to the discriminant initializer
471 // which is always an integer and thus doesn't need to know the
472 // enum's layout (or its tag type) to compute it during const eval
476 // B = A as isize + 4,
478 // The correct solution would be to add symbolic computations to miri,
479 // so we wouldn't have to compute and store the actual value
480 let var = if let hir::ExprKind::Path(ref qpath) = source.kind {
481 let res = cx.tables().qpath_res(qpath, source.hir_id);
482 cx.tables().node_type(source.hir_id).ty_adt_def().and_then(
483 |adt_def| match res {
485 DefKind::Ctor(CtorOf::Variant, CtorKind::Const),
488 let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
489 let (d, o) = adt_def.discriminant_def_for_variant(idx);
490 use rustc::ty::util::IntTypeExt;
491 let ty = adt_def.repr.discr_type();
492 let ty = ty.to_ty(cx.tcx());
502 let source = if let Some((did, offset, var_ty)) = var {
503 let mk_const = |literal| {
508 kind: ExprKind::Literal { literal, user_ty: None },
512 let offset = mk_const(ty::Const::from_bits(
515 cx.param_env.and(var_ty),
519 // in case we are offsetting from a computed discriminant
520 // and not the beginning of discriminants (which is always `0`)
521 let substs = InternalSubsts::identity_for_item(cx.tcx(), did);
522 let lhs = mk_const(cx.tcx().mk_const(ty::Const {
523 val: ty::ConstKind::Unevaluated(did, substs),
526 let bin = ExprKind::Binary { op: BinOp::Add, lhs, rhs: offset };
527 Expr { temp_lifetime, ty: var_ty, span: expr.span, kind: bin }.to_ref()
535 ExprKind::Cast { source }
538 if let Some(user_ty) = user_ty {
539 // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
540 // inefficient, revisit this when performance becomes an issue.
541 let cast_expr = Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind: cast };
542 debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
544 ExprKind::ValueTypeAscription {
545 source: cast_expr.to_ref(),
546 user_ty: Some(*user_ty),
552 hir::ExprKind::Type(ref source, ref ty) => {
553 let user_provided_types = cx.tables.user_provided_types();
554 let user_ty = user_provided_types.get(ty.hir_id).map(|u_ty| *u_ty);
555 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
556 if source.is_syntactic_place_expr() {
557 ExprKind::PlaceTypeAscription { source: source.to_ref(), user_ty }
559 ExprKind::ValueTypeAscription { source: source.to_ref(), user_ty }
562 hir::ExprKind::DropTemps(ref source) => ExprKind::Use { source: source.to_ref() },
563 hir::ExprKind::Box(ref value) => ExprKind::Box { value: value.to_ref() },
564 hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
565 hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
567 hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: v.to_ref() },
568 hir::ExprKind::Err => unreachable!(),
571 Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
574 fn user_substs_applied_to_res(
575 cx: &mut Cx<'a, 'tcx>,
578 ) -> Option<ty::CanonicalUserType<'tcx>> {
579 debug!("user_substs_applied_to_res: res={:?}", res);
580 let user_provided_type = match res {
581 // A reference to something callable -- e.g., a fn, method, or
582 // a tuple-struct or tuple-variant. This has the type of a
583 // `Fn` but with the user-given substitutions.
584 Res::Def(DefKind::Fn, _)
585 | Res::Def(DefKind::Method, _)
586 | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
587 | Res::Def(DefKind::Const, _)
588 | Res::Def(DefKind::AssocConst, _) => {
589 cx.tables().user_provided_types().get(hir_id).map(|u_ty| *u_ty)
592 // A unit struct/variant which is used as a value (e.g.,
593 // `None`). This has the type of the enum/struct that defines
594 // this variant -- but with the substitutions given by the
596 Res::Def(DefKind::Ctor(_, CtorKind::Const), _) => {
597 cx.user_substs_applied_to_ty_of_hir_id(hir_id)
600 // `Self` is used in expression as a tuple struct constructor or an unit struct constructor
601 Res::SelfCtor(_) => cx.user_substs_applied_to_ty_of_hir_id(hir_id),
603 _ => bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id),
605 debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
609 fn method_callee<'a, 'tcx>(
610 cx: &mut Cx<'a, 'tcx>,
613 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
615 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
616 let (def_id, substs, user_ty) = match overloaded_callee {
617 Some((def_id, substs)) => (def_id, substs, None),
619 let (kind, def_id) = cx
621 .type_dependent_def(expr.hir_id)
622 .unwrap_or_else(|| span_bug!(expr.span, "no type-dependent def for method callee"));
623 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, Res::Def(kind, def_id));
624 debug!("method_callee: user_ty={:?}", user_ty);
625 (def_id, cx.tables().node_substs(expr.hir_id), user_ty)
628 let ty = cx.tcx().mk_fn_def(def_id, substs);
633 kind: ExprKind::Literal { literal: ty::Const::zero_sized(cx.tcx(), ty), user_ty },
638 fn to_borrow_kind(&self) -> BorrowKind;
641 impl ToBorrowKind for AutoBorrowMutability {
642 fn to_borrow_kind(&self) -> BorrowKind {
643 use rustc::ty::adjustment::AllowTwoPhase;
645 AutoBorrowMutability::Mut { allow_two_phase_borrow } => BorrowKind::Mut {
646 allow_two_phase_borrow: match allow_two_phase_borrow {
647 AllowTwoPhase::Yes => true,
648 AllowTwoPhase::No => false,
651 AutoBorrowMutability::Not => BorrowKind::Shared,
656 impl ToBorrowKind for hir::Mutability {
657 fn to_borrow_kind(&self) -> BorrowKind {
659 hir::Mutability::Mut => BorrowKind::Mut { allow_two_phase_borrow: false },
660 hir::Mutability::Not => BorrowKind::Shared,
665 fn convert_arm<'tcx>(cx: &mut Cx<'_, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
667 pattern: cx.pattern_from_hir(&arm.pat),
668 guard: match arm.guard {
669 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
672 body: arm.body.to_ref(),
673 lint_level: LintLevel::Explicit(arm.hir_id),
674 scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
679 fn convert_path_expr<'a, 'tcx>(
680 cx: &mut Cx<'a, 'tcx>,
681 expr: &'tcx hir::Expr,
683 ) -> ExprKind<'tcx> {
684 let substs = cx.tables().node_substs(expr.hir_id);
686 // A regular function, constructor function or a constant.
687 Res::Def(DefKind::Fn, _)
688 | Res::Def(DefKind::Method, _)
689 | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
690 | Res::SelfCtor(..) => {
691 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
692 debug!("convert_path_expr: user_ty={:?}", user_ty);
694 literal: ty::Const::zero_sized(cx.tcx, cx.tables().node_type(expr.hir_id)),
699 Res::Def(DefKind::ConstParam, def_id) => {
700 let hir_id = cx.tcx.hir().as_local_hir_id(def_id).unwrap();
701 let item_id = cx.tcx.hir().get_parent_node(hir_id);
702 let item_def_id = cx.tcx.hir().local_def_id(item_id);
703 let generics = cx.tcx.generics_of(item_def_id);
704 let local_def_id = cx.tcx.hir().local_def_id(hir_id);
705 let index = generics.param_def_id_to_index[&local_def_id];
706 let name = cx.tcx.hir().name(hir_id);
707 let val = ty::ConstKind::Param(ty::ParamConst::new(index, name));
709 literal: cx.tcx.mk_const(ty::Const { val, ty: cx.tables().node_type(expr.hir_id) }),
714 Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => {
715 let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
716 debug!("convert_path_expr: (const) user_ty={:?}", user_ty);
718 literal: cx.tcx.mk_const(ty::Const {
719 val: ty::ConstKind::Unevaluated(def_id, substs),
720 ty: cx.tables().node_type(expr.hir_id),
726 Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
727 let user_provided_types = cx.tables.user_provided_types();
728 let user_provided_type = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
729 debug!("convert_path_expr: user_provided_type={:?}", user_provided_type);
730 let ty = cx.tables().node_type(expr.hir_id);
732 // A unit struct/variant which is used as a value.
733 // We return a completely different ExprKind here to account for this special case.
734 ty::Adt(adt_def, substs) => ExprKind::Adt {
736 variant_index: adt_def.variant_index_with_ctor_id(def_id),
738 user_ty: user_provided_type,
742 _ => bug!("unexpected ty: {:?}", ty),
746 // We encode uses of statics as a `*&STATIC` where the `&STATIC` part is
747 // a constant reference (or constant raw pointer for `static mut`) in MIR
748 Res::Def(DefKind::Static, id) => {
749 let ty = cx.tcx.static_ptr_ty(id);
750 let ptr = cx.tcx.alloc_map.lock().create_static_alloc(id);
751 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
757 kind: ExprKind::StaticRef {
758 literal: ty::Const::from_scalar(cx.tcx, Scalar::Ptr(ptr.into()), ty),
766 Res::Local(var_hir_id) => convert_var(cx, expr, var_hir_id),
768 _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
773 cx: &mut Cx<'_, 'tcx>,
774 expr: &'tcx hir::Expr,
775 var_hir_id: hir::HirId,
776 ) -> ExprKind<'tcx> {
781 .and_then(|upvars| upvars.get_full(&var_hir_id).map(|(i, _, _)| i));
784 "convert_var({:?}): upvar_index={:?}, body_owner={:?}",
785 var_hir_id, upvar_index, cx.body_owner
788 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
791 None => ExprKind::VarRef { id: var_hir_id },
793 Some(upvar_index) => {
794 let closure_def_id = cx.body_owner;
795 let upvar_id = ty::UpvarId {
796 var_path: ty::UpvarPath { hir_id: var_hir_id },
797 closure_expr_id: LocalDefId::from_def_id(closure_def_id),
799 let var_ty = cx.tables().node_type(var_hir_id);
801 // FIXME free regions in closures are not right
804 .node_type(cx.tcx.hir().local_def_id_to_hir_id(upvar_id.closure_expr_id));
806 // FIXME we're just hard-coding the idea that the
807 // signature will be &self or &mut self and hence will
808 // have a bound region with number 0
809 let region = ty::ReFree(ty::FreeRegion {
810 scope: closure_def_id,
811 bound_region: ty::BoundRegion::BrAnon(0),
813 let region = cx.tcx.mk_region(region);
815 let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.kind {
816 match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
817 ty::ClosureKind::Fn => {
818 let ref_closure_ty = cx.tcx.mk_ref(
820 ty::TypeAndMut { ty: closure_ty, mutbl: hir::Mutability::Not },
826 kind: ExprKind::Deref {
831 kind: ExprKind::SelfRef,
837 ty::ClosureKind::FnMut => {
838 let ref_closure_ty = cx.tcx.mk_ref(
840 ty::TypeAndMut { ty: closure_ty, mutbl: hir::Mutability::Mut },
846 kind: ExprKind::Deref {
851 kind: ExprKind::SelfRef,
857 ty::ClosureKind::FnOnce => Expr {
861 kind: ExprKind::SelfRef,
865 Expr { ty: closure_ty, temp_lifetime, span: expr.span, kind: ExprKind::SelfRef }
868 // at this point we have `self.n`, which loads up the upvar
870 ExprKind::Field { lhs: self_expr.to_ref(), name: Field::new(upvar_index) };
872 // ...but the upvar might be an `&T` or `&mut T` capture, at which
873 // point we need an implicit deref
874 match cx.tables().upvar_capture(upvar_id) {
875 ty::UpvarCapture::ByValue => field_kind,
876 ty::UpvarCapture::ByRef(borrow) => ExprKind::Deref {
881 ty::TypeAndMut { ty: var_ty, mutbl: borrow.kind.to_mutbl_lossy() },
893 fn bin_op(op: hir::BinOpKind) -> BinOp {
895 hir::BinOpKind::Add => BinOp::Add,
896 hir::BinOpKind::Sub => BinOp::Sub,
897 hir::BinOpKind::Mul => BinOp::Mul,
898 hir::BinOpKind::Div => BinOp::Div,
899 hir::BinOpKind::Rem => BinOp::Rem,
900 hir::BinOpKind::BitXor => BinOp::BitXor,
901 hir::BinOpKind::BitAnd => BinOp::BitAnd,
902 hir::BinOpKind::BitOr => BinOp::BitOr,
903 hir::BinOpKind::Shl => BinOp::Shl,
904 hir::BinOpKind::Shr => BinOp::Shr,
905 hir::BinOpKind::Eq => BinOp::Eq,
906 hir::BinOpKind::Lt => BinOp::Lt,
907 hir::BinOpKind::Le => BinOp::Le,
908 hir::BinOpKind::Ne => BinOp::Ne,
909 hir::BinOpKind::Ge => BinOp::Ge,
910 hir::BinOpKind::Gt => BinOp::Gt,
911 _ => bug!("no equivalent for ast binop {:?}", op),
915 fn overloaded_operator<'a, 'tcx>(
916 cx: &mut Cx<'a, 'tcx>,
917 expr: &'tcx hir::Expr,
918 args: Vec<ExprRef<'tcx>>,
919 ) -> ExprKind<'tcx> {
920 let fun = method_callee(cx, expr, expr.span, None);
921 ExprKind::Call { ty: fun.ty, fun: fun.to_ref(), args, from_hir_call: false }
924 fn overloaded_place<'a, 'tcx>(
925 cx: &mut Cx<'a, 'tcx>,
926 expr: &'tcx hir::Expr,
928 overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
929 args: Vec<ExprRef<'tcx>>,
930 ) -> ExprKind<'tcx> {
931 // For an overloaded *x or x[y] expression of type T, the method
932 // call returns an &T and we must add the deref so that the types
933 // line up (this is because `*x` and `x[y]` represent places):
935 let recv_ty = match args[0] {
936 ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
937 ExprRef::Mirror(ref e) => e.ty,
940 // Reconstruct the output assuming it's a reference with the
941 // same region and mutability as the receiver. This holds for
942 // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
943 let (region, mutbl) = match recv_ty.kind {
944 ty::Ref(region, _, mutbl) => (region, mutbl),
945 _ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
947 let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut { ty: place_ty, mutbl });
949 // construct the complete expression `foo()` for the overloaded call,
950 // which will yield the &T type
951 let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
952 let fun = method_callee(cx, expr, expr.span, overloaded_callee);
953 let ref_expr = Expr {
957 kind: ExprKind::Call { ty: fun.ty, fun: fun.to_ref(), args, from_hir_call: false },
960 // construct and return a deref wrapper `*foo()`
961 ExprKind::Deref { arg: ref_expr.to_ref() }
964 fn capture_upvar<'tcx>(
965 cx: &mut Cx<'_, 'tcx>,
966 closure_expr: &'tcx hir::Expr,
967 var_hir_id: hir::HirId,
970 let upvar_id = ty::UpvarId {
971 var_path: ty::UpvarPath { hir_id: var_hir_id },
972 closure_expr_id: cx.tcx.hir().local_def_id(closure_expr.hir_id).to_local(),
974 let upvar_capture = cx.tables().upvar_capture(upvar_id);
975 let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
976 let var_ty = cx.tables().node_type(var_hir_id);
977 let captured_var = Expr {
980 span: closure_expr.span,
981 kind: convert_var(cx, closure_expr, var_hir_id),
983 match upvar_capture {
984 ty::UpvarCapture::ByValue => captured_var.to_ref(),
985 ty::UpvarCapture::ByRef(upvar_borrow) => {
986 let borrow_kind = match upvar_borrow.kind {
987 ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
988 ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
989 ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false },
994 span: closure_expr.span,
995 kind: ExprKind::Borrow { borrow_kind, arg: captured_var.to_ref() },
1002 /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExprRef.
1003 fn field_refs<'a, 'tcx>(
1004 cx: &mut Cx<'a, 'tcx>,
1005 fields: &'tcx [hir::Field],
1006 ) -> Vec<FieldExprRef<'tcx>> {
1009 .map(|field| FieldExprRef {
1010 name: Field::new(cx.tcx.field_index(field.hir_id, cx.tables)),
1011 expr: field.expr.to_ref(),