compiler/rustc_mir_build/src/thir/cx/expr.rs

   1 use crate::thir::cx::region::Scope;
   2 use crate::thir::cx::Cx;
   3 use crate::thir::util::UserAnnotatedTyHelpers;
   4 use rustc_data_structures::stack::ensure_sufficient_stack;
   5 use rustc_hir as hir;
   6 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
   7 use rustc_index::vec::Idx;
   8 use rustc_middle::hir::place::Place as HirPlace;
   9 use rustc_middle::hir::place::PlaceBase as HirPlaceBase;
  10 use rustc_middle::hir::place::ProjectionKind as HirProjectionKind;
  11 use rustc_middle::middle::region;
  12 use rustc_middle::mir::{self, BinOp, BorrowKind, Field, UnOp};
  13 use rustc_middle::thir::*;
  14 use rustc_middle::ty::adjustment::{
  15     Adjust, Adjustment, AutoBorrow, AutoBorrowMutability, PointerCast,
  16 };
  17 use rustc_middle::ty::subst::{InternalSubsts, SubstsRef};
  18 use rustc_middle::ty::{
  19     self, AdtKind, InlineConstSubsts, InlineConstSubstsParts, ScalarInt, Ty, UpvarSubsts, UserType,
  20 };
  21 use rustc_span::def_id::DefId;
  22 use rustc_span::Span;
  23 use rustc_target::abi::VariantIdx;
  24
  25 impl<'tcx> Cx<'tcx> {
  26     pub(crate) fn mirror_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) -> ExprId {
  27         // `mirror_expr` is recursing very deep. Make sure the stack doesn't overflow.
  28         ensure_sufficient_stack(|| self.mirror_expr_inner(expr))
  29     }
  30
  31     pub(crate) fn mirror_exprs(&mut self, exprs: &'tcx [hir::Expr<'tcx>]) -> Box<[ExprId]> {
  32         exprs.iter().map(|expr| self.mirror_expr_inner(expr)).collect()
  33     }
  34
  35     #[instrument(level = "trace", skip(self, hir_expr))]
  36     pub(super) fn mirror_expr_inner(&mut self, hir_expr: &'tcx hir::Expr<'tcx>) -> ExprId {
  37         let temp_lifetime =
  38             self.rvalue_scopes.temporary_scope(self.region_scope_tree, hir_expr.hir_id.local_id);
  39         let expr_scope =
  40             region::Scope { id: hir_expr.hir_id.local_id, data: region::ScopeData::Node };
  41
  42         trace!(?hir_expr.hir_id, ?hir_expr.span);
  43
  44         let mut expr = self.make_mirror_unadjusted(hir_expr);
  45
  46         let adjustment_span = match self.adjustment_span {
  47             Some((hir_id, span)) if hir_id == hir_expr.hir_id => Some(span),
  48             _ => None,
  49         };
  50
  51         trace!(?expr.ty);
  52
  53         // Now apply adjustments, if any.
  54         for adjustment in self.typeck_results.expr_adjustments(hir_expr) {
  55             trace!(?expr, ?adjustment);
  56             let span = expr.span;
  57             expr =
  58                 self.apply_adjustment(hir_expr, expr, adjustment, adjustment_span.unwrap_or(span));
  59         }
  60
  61         trace!(?expr.ty, "after adjustments");
  62
  63         // Next, wrap this up in the expr's scope.
  64         expr = Expr {
  65             temp_lifetime,
  66             ty: expr.ty,
  67             span: hir_expr.span,
  68             kind: ExprKind::Scope {
  69                 region_scope: expr_scope,
  70                 value: self.thir.exprs.push(expr),
  71                 lint_level: LintLevel::Explicit(hir_expr.hir_id),
  72             },
  73         };
  74
  75         // Finally, create a destruction scope, if any.
  76         if let Some(region_scope) =
  77             self.region_scope_tree.opt_destruction_scope(hir_expr.hir_id.local_id)
  78         {
  79             expr = Expr {
  80                 temp_lifetime,
  81                 ty: expr.ty,
  82                 span: hir_expr.span,
  83                 kind: ExprKind::Scope {
  84                     region_scope,
  85                     value: self.thir.exprs.push(expr),
  86                     lint_level: LintLevel::Inherited,
  87                 },
  88             };
  89         }
  90
  91         // OK, all done!
  92         self.thir.exprs.push(expr)
  93     }
  94
  95     fn apply_adjustment(
  96         &mut self,
  97         hir_expr: &'tcx hir::Expr<'tcx>,
  98         mut expr: Expr<'tcx>,
  99         adjustment: &Adjustment<'tcx>,
 100         mut span: Span,
 101     ) -> Expr<'tcx> {
 102         let Expr { temp_lifetime, .. } = expr;
 103
 104         // Adjust the span from the block, to the last expression of the
 105         // block. This is a better span when returning a mutable reference
 106         // with too short a lifetime. The error message will use the span
 107         // from the assignment to the return place, which should only point
 108         // at the returned value, not the entire function body.
 109         //
 110         // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
 111         //      x
 112         //   // ^ error message points at this expression.
 113         // }
 114         let mut adjust_span = |expr: &mut Expr<'tcx>| {
 115             if let ExprKind::Block { block } = expr.kind {
 116                 if let Some(last_expr) = self.thir[block].expr {
 117                     span = self.thir[last_expr].span;
 118                     expr.span = span;
 119                 }
 120             }
 121         };
 122
 123         let kind = match adjustment.kind {
 124             Adjust::Pointer(PointerCast::Unsize) => {
 125                 adjust_span(&mut expr);
 126                 ExprKind::Pointer { cast: PointerCast::Unsize, source: self.thir.exprs.push(expr) }
 127             }
 128             Adjust::Pointer(cast) => ExprKind::Pointer { cast, source: self.thir.exprs.push(expr) },
 129             Adjust::NeverToAny => ExprKind::NeverToAny { source: self.thir.exprs.push(expr) },
 130             Adjust::Deref(None) => {
 131                 adjust_span(&mut expr);
 132                 ExprKind::Deref { arg: self.thir.exprs.push(expr) }
 133             }
 134             Adjust::Deref(Some(deref)) => {
 135                 // We don't need to do call adjust_span here since
 136                 // deref coercions always start with a built-in deref.
 137                 let call = deref.method_call(self.tcx(), expr.ty);
 138
 139                 expr = Expr {
 140                     temp_lifetime,
 141                     ty: self
 142                         .tcx
 143                         .mk_ref(deref.region, ty::TypeAndMut { ty: expr.ty, mutbl: deref.mutbl }),
 144                     span,
 145                     kind: ExprKind::Borrow {
 146                         borrow_kind: deref.mutbl.to_borrow_kind(),
 147                         arg: self.thir.exprs.push(expr),
 148                     },
 149                 };
 150
 151                 let expr = Box::new([self.thir.exprs.push(expr)]);
 152
 153                 self.overloaded_place(hir_expr, adjustment.target, Some(call), expr, deref.span)
 154             }
 155             Adjust::Borrow(AutoBorrow::Ref(_, m)) => ExprKind::Borrow {
 156                 borrow_kind: m.to_borrow_kind(),
 157                 arg: self.thir.exprs.push(expr),
 158             },
 159             Adjust::Borrow(AutoBorrow::RawPtr(mutability)) => {
 160                 ExprKind::AddressOf { mutability, arg: self.thir.exprs.push(expr) }
 161             }
 162         };
 163
 164         Expr { temp_lifetime, ty: adjustment.target, span, kind }
 165     }
 166
 167     /// Lowers a cast expression.
 168     ///
 169     /// Dealing with user type annotations is left to the caller.
 170     fn mirror_expr_cast(
 171         &mut self,
 172         source: &'tcx hir::Expr<'tcx>,
 173         temp_lifetime: Option<Scope>,
 174         span: Span,
 175     ) -> ExprKind<'tcx> {
 176         let tcx = self.tcx;
 177
 178         // Check to see if this cast is a "coercion cast", where the cast is actually done
 179         // using a coercion (or is a no-op).
 180         if self.typeck_results().is_coercion_cast(source.hir_id) {
 181             // Convert the lexpr to a vexpr.
 182             ExprKind::Use { source: self.mirror_expr(source) }
 183         } else if self.typeck_results().expr_ty(source).is_region_ptr() {
 184             // Special cased so that we can type check that the element
 185             // type of the source matches the pointed to type of the
 186             // destination.
 187             ExprKind::Pointer {
 188                 source: self.mirror_expr(source),
 189                 cast: PointerCast::ArrayToPointer,
 190             }
 191         } else {
 192             // check whether this is casting an enum variant discriminant
 193             // to prevent cycles, we refer to the discriminant initializer
 194             // which is always an integer and thus doesn't need to know the
 195             // enum's layout (or its tag type) to compute it during const eval
 196             // Example:
 197             // enum Foo {
 198             //     A,
 199             //     B = A as isize + 4,
 200             // }
 201             // The correct solution would be to add symbolic computations to miri,
 202             // so we wouldn't have to compute and store the actual value
 203
 204             let hir::ExprKind::Path(ref qpath) = source.kind else {
 205                 return ExprKind::Cast { source: self.mirror_expr(source)};
 206             };
 207
 208             let res = self.typeck_results().qpath_res(qpath, source.hir_id);
 209             let ty = self.typeck_results().node_type(source.hir_id);
 210             let ty::Adt(adt_def, substs) = ty.kind() else {
 211                 return ExprKind::Cast { source: self.mirror_expr(source)};
 212             };
 213
 214             let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), variant_ctor_id) = res else {
 215                 return ExprKind::Cast { source: self.mirror_expr(source)};
 216             };
 217
 218             let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
 219             let (discr_did, discr_offset) = adt_def.discriminant_def_for_variant(idx);
 220
 221             use rustc_middle::ty::util::IntTypeExt;
 222             let ty = adt_def.repr().discr_type();
 223             let discr_ty = ty.to_ty(tcx);
 224
 225             let param_env_ty = self.param_env.and(discr_ty);
 226             let size = tcx
 227                 .layout_of(param_env_ty)
 228                 .unwrap_or_else(|e| {
 229                     panic!("could not compute layout for {:?}: {:?}", param_env_ty, e)
 230                 })
 231                 .size;
 232
 233             let lit = ScalarInt::try_from_uint(discr_offset as u128, size).unwrap();
 234             let kind = ExprKind::NonHirLiteral { lit, user_ty: None };
 235             let offset = self.thir.exprs.push(Expr { temp_lifetime, ty: discr_ty, span, kind });
 236
 237             let source = match discr_did {
 238                 // in case we are offsetting from a computed discriminant
 239                 // and not the beginning of discriminants (which is always `0`)
 240                 Some(did) => {
 241                     let kind = ExprKind::NamedConst { def_id: did, substs, user_ty: None };
 242                     let lhs =
 243                         self.thir.exprs.push(Expr { temp_lifetime, ty: discr_ty, span, kind });
 244                     let bin = ExprKind::Binary { op: BinOp::Add, lhs, rhs: offset };
 245                     self.thir.exprs.push(Expr {
 246                         temp_lifetime,
 247                         ty: discr_ty,
 248                         span: span,
 249                         kind: bin,
 250                     })
 251                 }
 252                 None => offset,
 253             };
 254
 255             ExprKind::Cast { source }
 256         }
 257     }
 258
 259     fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx> {
 260         let tcx = self.tcx;
 261         let expr_ty = self.typeck_results().expr_ty(expr);
 262         let expr_span = expr.span;
 263         let temp_lifetime =
 264             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 265
 266         let kind = match expr.kind {
 267             // Here comes the interesting stuff:
 268             hir::ExprKind::MethodCall(segment, receiver, ref args, fn_span) => {
 269                 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
 270                 let expr = self.method_callee(expr, segment.ident.span, None);
 271                 // When we apply adjustments to the receiver, use the span of
 272                 // the overall method call for better diagnostics. args[0]
 273                 // is guaranteed to exist, since a method call always has a receiver.
 274                 let old_adjustment_span =
 275                     self.adjustment_span.replace((receiver.hir_id, expr_span));
 276                 info!("Using method span: {:?}", expr.span);
 277                 let args = std::iter::once(receiver)
 278                     .chain(args.iter())
 279                     .map(|expr| self.mirror_expr(expr))
 280                     .collect();
 281                 self.adjustment_span = old_adjustment_span;
 282                 ExprKind::Call {
 283                     ty: expr.ty,
 284                     fun: self.thir.exprs.push(expr),
 285                     args,
 286                     from_hir_call: true,
 287                     fn_span,
 288                 }
 289             }
 290
 291             hir::ExprKind::Call(ref fun, ref args) => {
 292                 if self.typeck_results().is_method_call(expr) {
 293                     // The callee is something implementing Fn, FnMut, or FnOnce.
 294                     // Find the actual method implementation being called and
 295                     // build the appropriate UFCS call expression with the
 296                     // callee-object as expr parameter.
 297
 298                     // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
 299
 300                     let method = self.method_callee(expr, fun.span, None);
 301
 302                     let arg_tys = args.iter().map(|e| self.typeck_results().expr_ty_adjusted(e));
 303                     let tupled_args = Expr {
 304                         ty: tcx.mk_tup(arg_tys),
 305                         temp_lifetime,
 306                         span: expr.span,
 307                         kind: ExprKind::Tuple { fields: self.mirror_exprs(args) },
 308                     };
 309                     let tupled_args = self.thir.exprs.push(tupled_args);
 310
 311                     ExprKind::Call {
 312                         ty: method.ty,
 313                         fun: self.thir.exprs.push(method),
 314                         args: Box::new([self.mirror_expr(fun), tupled_args]),
 315                         from_hir_call: true,
 316                         fn_span: expr.span,
 317                     }
 318                 } else {
 319                     let adt_data =
 320                         if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = fun.kind {
 321                             // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
 322                             expr_ty.ty_adt_def().and_then(|adt_def| match path.res {
 323                                 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) => {
 324                                     Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id)))
 325                                 }
 326                                 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
 327                                 _ => None,
 328                             })
 329                         } else {
 330                             None
 331                         };
 332                     if let Some((adt_def, index)) = adt_data {
 333                         let substs = self.typeck_results().node_substs(fun.hir_id);
 334                         let user_provided_types = self.typeck_results().user_provided_types();
 335                         let user_ty =
 336                             user_provided_types.get(fun.hir_id).copied().map(|mut u_ty| {
 337                                 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
 338                                     *did = adt_def.did();
 339                                 }
 340                                 Box::new(u_ty)
 341                             });
 342                         debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
 343
 344                         let field_refs = args
 345                             .iter()
 346                             .enumerate()
 347                             .map(|(idx, e)| FieldExpr {
 348                                 name: Field::new(idx),
 349                                 expr: self.mirror_expr(e),
 350                             })
 351                             .collect();
 352                         ExprKind::Adt(Box::new(AdtExpr {
 353                             adt_def,
 354                             substs,
 355                             variant_index: index,
 356                             fields: field_refs,
 357                             user_ty,
 358                             base: None,
 359                         }))
 360                     } else {
 361                         ExprKind::Call {
 362                             ty: self.typeck_results().node_type(fun.hir_id),
 363                             fun: self.mirror_expr(fun),
 364                             args: self.mirror_exprs(args),
 365                             from_hir_call: true,
 366                             fn_span: expr.span,
 367                         }
 368                     }
 369                 }
 370             }
 371
 372             hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, ref arg) => {
 373                 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: self.mirror_expr(arg) }
 374             }
 375
 376             hir::ExprKind::AddrOf(hir::BorrowKind::Raw, mutability, ref arg) => {
 377                 ExprKind::AddressOf { mutability, arg: self.mirror_expr(arg) }
 378             }
 379
 380             hir::ExprKind::Block(ref blk, _) => ExprKind::Block { block: self.mirror_block(blk) },
 381
 382             hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
 383                 ExprKind::Assign { lhs: self.mirror_expr(lhs), rhs: self.mirror_expr(rhs) }
 384             }
 385
 386             hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
 387                 if self.typeck_results().is_method_call(expr) {
 388                     let lhs = self.mirror_expr(lhs);
 389                     let rhs = self.mirror_expr(rhs);
 390                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 391                 } else {
 392                     ExprKind::AssignOp {
 393                         op: bin_op(op.node),
 394                         lhs: self.mirror_expr(lhs),
 395                         rhs: self.mirror_expr(rhs),
 396                     }
 397                 }
 398             }
 399
 400             hir::ExprKind::Lit(ref lit) => ExprKind::Literal { lit, neg: false },
 401
 402             hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
 403                 if self.typeck_results().is_method_call(expr) {
 404                     let lhs = self.mirror_expr(lhs);
 405                     let rhs = self.mirror_expr(rhs);
 406                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 407                 } else {
 408                     // FIXME overflow
 409                     match op.node {
 410                         hir::BinOpKind::And => ExprKind::LogicalOp {
 411                             op: LogicalOp::And,
 412                             lhs: self.mirror_expr(lhs),
 413                             rhs: self.mirror_expr(rhs),
 414                         },
 415                         hir::BinOpKind::Or => ExprKind::LogicalOp {
 416                             op: LogicalOp::Or,
 417                             lhs: self.mirror_expr(lhs),
 418                             rhs: self.mirror_expr(rhs),
 419                         },
 420                         _ => {
 421                             let op = bin_op(op.node);
 422                             ExprKind::Binary {
 423                                 op,
 424                                 lhs: self.mirror_expr(lhs),
 425                                 rhs: self.mirror_expr(rhs),
 426                             }
 427                         }
 428                     }
 429                 }
 430             }
 431
 432             hir::ExprKind::Index(ref lhs, ref index) => {
 433                 if self.typeck_results().is_method_call(expr) {
 434                     let lhs = self.mirror_expr(lhs);
 435                     let index = self.mirror_expr(index);
 436                     self.overloaded_place(expr, expr_ty, None, Box::new([lhs, index]), expr.span)
 437                 } else {
 438                     ExprKind::Index { lhs: self.mirror_expr(lhs), index: self.mirror_expr(index) }
 439                 }
 440             }
 441
 442             hir::ExprKind::Unary(hir::UnOp::Deref, ref arg) => {
 443                 if self.typeck_results().is_method_call(expr) {
 444                     let arg = self.mirror_expr(arg);
 445                     self.overloaded_place(expr, expr_ty, None, Box::new([arg]), expr.span)
 446                 } else {
 447                     ExprKind::Deref { arg: self.mirror_expr(arg) }
 448                 }
 449             }
 450
 451             hir::ExprKind::Unary(hir::UnOp::Not, ref arg) => {
 452                 if self.typeck_results().is_method_call(expr) {
 453                     let arg = self.mirror_expr(arg);
 454                     self.overloaded_operator(expr, Box::new([arg]))
 455                 } else {
 456                     ExprKind::Unary { op: UnOp::Not, arg: self.mirror_expr(arg) }
 457                 }
 458             }
 459
 460             hir::ExprKind::Unary(hir::UnOp::Neg, ref arg) => {
 461                 if self.typeck_results().is_method_call(expr) {
 462                     let arg = self.mirror_expr(arg);
 463                     self.overloaded_operator(expr, Box::new([arg]))
 464                 } else if let hir::ExprKind::Lit(ref lit) = arg.kind {
 465                     ExprKind::Literal { lit, neg: true }
 466                 } else {
 467                     ExprKind::Unary { op: UnOp::Neg, arg: self.mirror_expr(arg) }
 468                 }
 469             }
 470
 471             hir::ExprKind::Struct(ref qpath, ref fields, ref base) => match expr_ty.kind() {
 472                 ty::Adt(adt, substs) => match adt.adt_kind() {
 473                     AdtKind::Struct | AdtKind::Union => {
 474                         let user_provided_types = self.typeck_results().user_provided_types();
 475                         let user_ty = user_provided_types.get(expr.hir_id).copied().map(Box::new);
 476                         debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
 477                         ExprKind::Adt(Box::new(AdtExpr {
 478                             adt_def: *adt,
 479                             variant_index: VariantIdx::new(0),
 480                             substs,
 481                             user_ty,
 482                             fields: self.field_refs(fields),
 483                             base: base.as_ref().map(|base| FruInfo {
 484                                 base: self.mirror_expr(base),
 485                                 field_types: self.typeck_results().fru_field_types()[expr.hir_id]
 486                                     .iter()
 487                                     .copied()
 488                                     .collect(),
 489                             }),
 490                         }))
 491                     }
 492                     AdtKind::Enum => {
 493                         let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 494                         match res {
 495                             Res::Def(DefKind::Variant, variant_id) => {
 496                                 assert!(base.is_none());
 497
 498                                 let index = adt.variant_index_with_id(variant_id);
 499                                 let user_provided_types =
 500                                     self.typeck_results().user_provided_types();
 501                                 let user_ty =
 502                                     user_provided_types.get(expr.hir_id).copied().map(Box::new);
 503                                 debug!("make_mirror_unadjusted: (variant) user_ty={:?}", user_ty);
 504                                 ExprKind::Adt(Box::new(AdtExpr {
 505                                     adt_def: *adt,
 506                                     variant_index: index,
 507                                     substs,
 508                                     user_ty,
 509                                     fields: self.field_refs(fields),
 510                                     base: None,
 511                                 }))
 512                             }
 513                             _ => {
 514                                 span_bug!(expr.span, "unexpected res: {:?}", res);
 515                             }
 516                         }
 517                     }
 518                 },
 519                 _ => {
 520                     span_bug!(expr.span, "unexpected type for struct literal: {:?}", expr_ty);
 521                 }
 522             },
 523
 524             hir::ExprKind::Closure { .. } => {
 525                 let closure_ty = self.typeck_results().expr_ty(expr);
 526                 let (def_id, substs, movability) = match *closure_ty.kind() {
 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))
 530                     }
 531                     _ => {
 532                         span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
 533                     }
 534                 };
 535                 let def_id = def_id.expect_local();
 536
 537                 let upvars = self
 538                     .typeck_results
 539                     .closure_min_captures_flattened(def_id)
 540                     .zip(substs.upvar_tys())
 541                     .map(|(captured_place, ty)| {
 542                         let upvars = self.capture_upvar(expr, captured_place, ty);
 543                         self.thir.exprs.push(upvars)
 544                     })
 545                     .collect();
 546
 547                 // Convert the closure fake reads, if any, from hir `Place` to ExprRef
 548                 let fake_reads = match self.typeck_results.closure_fake_reads.get(&def_id) {
 549                     Some(fake_reads) => fake_reads
 550                         .iter()
 551                         .map(|(place, cause, hir_id)| {
 552                             let expr = self.convert_captured_hir_place(expr, place.clone());
 553                             (self.thir.exprs.push(expr), *cause, *hir_id)
 554                         })
 555                         .collect(),
 556                     None => Vec::new(),
 557                 };
 558
 559                 ExprKind::Closure(Box::new(ClosureExpr {
 560                     closure_id: def_id,
 561                     substs,
 562                     upvars,
 563                     movability,
 564                     fake_reads,
 565                 }))
 566             }
 567
 568             hir::ExprKind::Path(ref qpath) => {
 569                 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 570                 self.convert_path_expr(expr, res)
 571             }
 572
 573             hir::ExprKind::InlineAsm(ref asm) => ExprKind::InlineAsm(Box::new(InlineAsmExpr {
 574                 template: asm.template,
 575                 operands: asm
 576                     .operands
 577                     .iter()
 578                     .map(|(op, _op_sp)| match *op {
 579                         hir::InlineAsmOperand::In { reg, ref expr } => {
 580                             InlineAsmOperand::In { reg, expr: self.mirror_expr(expr) }
 581                         }
 582                         hir::InlineAsmOperand::Out { reg, late, ref expr } => {
 583                             InlineAsmOperand::Out {
 584                                 reg,
 585                                 late,
 586                                 expr: expr.as_ref().map(|expr| self.mirror_expr(expr)),
 587                             }
 588                         }
 589                         hir::InlineAsmOperand::InOut { reg, late, ref expr } => {
 590                             InlineAsmOperand::InOut { reg, late, expr: self.mirror_expr(expr) }
 591                         }
 592                         hir::InlineAsmOperand::SplitInOut {
 593                             reg,
 594                             late,
 595                             ref in_expr,
 596                             ref out_expr,
 597                         } => InlineAsmOperand::SplitInOut {
 598                             reg,
 599                             late,
 600                             in_expr: self.mirror_expr(in_expr),
 601                             out_expr: out_expr.as_ref().map(|expr| self.mirror_expr(expr)),
 602                         },
 603                         hir::InlineAsmOperand::Const { ref anon_const } => {
 604                             let anon_const_def_id = tcx.hir().local_def_id(anon_const.hir_id);
 605                             let value = mir::ConstantKind::from_anon_const(
 606                                 tcx,
 607                                 anon_const_def_id,
 608                                 self.param_env,
 609                             );
 610                             let span = tcx.hir().span(anon_const.hir_id);
 611
 612                             InlineAsmOperand::Const { value, span }
 613                         }
 614                         hir::InlineAsmOperand::SymFn { ref anon_const } => {
 615                             let anon_const_def_id = tcx.hir().local_def_id(anon_const.hir_id);
 616                             let value = mir::ConstantKind::from_anon_const(
 617                                 tcx,
 618                                 anon_const_def_id,
 619                                 self.param_env,
 620                             );
 621                             let span = tcx.hir().span(anon_const.hir_id);
 622
 623                             InlineAsmOperand::SymFn { value, span }
 624                         }
 625                         hir::InlineAsmOperand::SymStatic { path: _, def_id } => {
 626                             InlineAsmOperand::SymStatic { def_id }
 627                         }
 628                     })
 629                     .collect(),
 630                 options: asm.options,
 631                 line_spans: asm.line_spans,
 632             })),
 633
 634             hir::ExprKind::ConstBlock(ref anon_const) => {
 635                 let ty = self.typeck_results().node_type(anon_const.hir_id);
 636                 let did = tcx.hir().local_def_id(anon_const.hir_id).to_def_id();
 637                 let typeck_root_def_id = tcx.typeck_root_def_id(did);
 638                 let parent_substs =
 639                     tcx.erase_regions(InternalSubsts::identity_for_item(tcx, typeck_root_def_id));
 640                 let substs =
 641                     InlineConstSubsts::new(tcx, InlineConstSubstsParts { parent_substs, ty })
 642                         .substs;
 643
 644                 ExprKind::ConstBlock { did, substs }
 645             }
 646             // Now comes the rote stuff:
 647             hir::ExprKind::Repeat(ref v, _) => {
 648                 let ty = self.typeck_results().expr_ty(expr);
 649                 let ty::Array(_, count) = ty.kind() else {
 650                     span_bug!(expr.span, "unexpected repeat expr ty: {:?}", ty);
 651                 };
 652
 653                 ExprKind::Repeat { value: self.mirror_expr(v), count: *count }
 654             }
 655             hir::ExprKind::Ret(ref v) => {
 656                 ExprKind::Return { value: v.as_ref().map(|v| self.mirror_expr(v)) }
 657             }
 658             hir::ExprKind::Break(dest, ref value) => match dest.target_id {
 659                 Ok(target_id) => ExprKind::Break {
 660                     label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node },
 661                     value: value.as_ref().map(|value| self.mirror_expr(value)),
 662                 },
 663                 Err(err) => bug!("invalid loop id for break: {}", err),
 664             },
 665             hir::ExprKind::Continue(dest) => match dest.target_id {
 666                 Ok(loop_id) => ExprKind::Continue {
 667                     label: region::Scope { id: loop_id.local_id, data: region::ScopeData::Node },
 668                 },
 669                 Err(err) => bug!("invalid loop id for continue: {}", err),
 670             },
 671             hir::ExprKind::Let(let_expr) => ExprKind::Let {
 672                 expr: self.mirror_expr(let_expr.init),
 673                 pat: self.pattern_from_hir(let_expr.pat),
 674             },
 675             hir::ExprKind::If(cond, then, else_opt) => ExprKind::If {
 676                 if_then_scope: region::Scope {
 677                     id: then.hir_id.local_id,
 678                     data: region::ScopeData::IfThen,
 679                 },
 680                 cond: self.mirror_expr(cond),
 681                 then: self.mirror_expr(then),
 682                 else_opt: else_opt.map(|el| self.mirror_expr(el)),
 683             },
 684             hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
 685                 scrutinee: self.mirror_expr(discr),
 686                 arms: arms.iter().map(|a| self.convert_arm(a)).collect(),
 687             },
 688             hir::ExprKind::Loop(ref body, ..) => {
 689                 let block_ty = self.typeck_results().node_type(body.hir_id);
 690                 let temp_lifetime = self
 691                     .rvalue_scopes
 692                     .temporary_scope(self.region_scope_tree, body.hir_id.local_id);
 693                 let block = self.mirror_block(body);
 694                 let body = self.thir.exprs.push(Expr {
 695                     ty: block_ty,
 696                     temp_lifetime,
 697                     span: self.thir[block].span,
 698                     kind: ExprKind::Block { block },
 699                 });
 700                 ExprKind::Loop { body }
 701             }
 702             hir::ExprKind::Field(ref source, ..) => ExprKind::Field {
 703                 lhs: self.mirror_expr(source),
 704                 variant_index: VariantIdx::new(0),
 705                 name: Field::new(tcx.field_index(expr.hir_id, self.typeck_results)),
 706             },
 707             hir::ExprKind::Cast(ref source, ref cast_ty) => {
 708                 // Check for a user-given type annotation on this `cast`
 709                 let user_provided_types = self.typeck_results.user_provided_types();
 710                 let user_ty = user_provided_types.get(cast_ty.hir_id);
 711
 712                 debug!(
 713                     "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
 714                     expr, cast_ty.hir_id, user_ty,
 715                 );
 716
 717                 let cast = self.mirror_expr_cast(*source, temp_lifetime, expr.span);
 718
 719                 if let Some(user_ty) = user_ty {
 720                     // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
 721                     //       inefficient, revisit this when performance becomes an issue.
 722                     let cast_expr = self.thir.exprs.push(Expr {
 723                         temp_lifetime,
 724                         ty: expr_ty,
 725                         span: expr.span,
 726                         kind: cast,
 727                     });
 728                     debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
 729
 730                     ExprKind::ValueTypeAscription {
 731                         source: cast_expr,
 732                         user_ty: Some(Box::new(*user_ty)),
 733                     }
 734                 } else {
 735                     cast
 736                 }
 737             }
 738             hir::ExprKind::Type(ref source, ref ty) => {
 739                 let user_provided_types = self.typeck_results.user_provided_types();
 740                 let user_ty = user_provided_types.get(ty.hir_id).copied().map(Box::new);
 741                 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
 742                 let mirrored = self.mirror_expr(source);
 743                 if source.is_syntactic_place_expr() {
 744                     ExprKind::PlaceTypeAscription { source: mirrored, user_ty }
 745                 } else {
 746                     ExprKind::ValueTypeAscription { source: mirrored, user_ty }
 747                 }
 748             }
 749             hir::ExprKind::DropTemps(ref source) => {
 750                 ExprKind::Use { source: self.mirror_expr(source) }
 751             }
 752             hir::ExprKind::Box(ref value) => ExprKind::Box { value: self.mirror_expr(value) },
 753             hir::ExprKind::Array(ref fields) => {
 754                 ExprKind::Array { fields: self.mirror_exprs(fields) }
 755             }
 756             hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: self.mirror_exprs(fields) },
 757
 758             hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: self.mirror_expr(v) },
 759             hir::ExprKind::Err => unreachable!(),
 760         };
 761
 762         Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
 763     }
 764
 765     fn user_substs_applied_to_res(
 766         &mut self,
 767         hir_id: hir::HirId,
 768         res: Res,
 769     ) -> Option<Box<ty::CanonicalUserType<'tcx>>> {
 770         debug!("user_substs_applied_to_res: res={:?}", res);
 771         let user_provided_type = match res {
 772             // A reference to something callable -- e.g., a fn, method, or
 773             // a tuple-struct or tuple-variant. This has the type of a
 774             // `Fn` but with the user-given substitutions.
 775             Res::Def(DefKind::Fn, _)
 776             | Res::Def(DefKind::AssocFn, _)
 777             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 778             | Res::Def(DefKind::Const, _)
 779             | Res::Def(DefKind::AssocConst, _) => {
 780                 self.typeck_results().user_provided_types().get(hir_id).copied().map(Box::new)
 781             }
 782
 783             // A unit struct/variant which is used as a value (e.g.,
 784             // `None`). This has the type of the enum/struct that defines
 785             // this variant -- but with the substitutions given by the
 786             // user.
 787             Res::Def(DefKind::Ctor(_, CtorKind::Const), _) => {
 788                 self.user_substs_applied_to_ty_of_hir_id(hir_id).map(Box::new)
 789             }
 790
 791             // `Self` is used in expression as a tuple struct constructor or a unit struct constructor
 792             Res::SelfCtor(_) => self.user_substs_applied_to_ty_of_hir_id(hir_id).map(Box::new),
 793
 794             _ => bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id),
 795         };
 796         debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
 797         user_provided_type
 798     }
 799
 800     fn method_callee(
 801         &mut self,
 802         expr: &hir::Expr<'_>,
 803         span: Span,
 804         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 805     ) -> Expr<'tcx> {
 806         let temp_lifetime =
 807             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 808         let (def_id, substs, user_ty) = match overloaded_callee {
 809             Some((def_id, substs)) => (def_id, substs, None),
 810             None => {
 811                 let (kind, def_id) =
 812                     self.typeck_results().type_dependent_def(expr.hir_id).unwrap_or_else(|| {
 813                         span_bug!(expr.span, "no type-dependent def for method callee")
 814                     });
 815                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, Res::Def(kind, def_id));
 816                 debug!("method_callee: user_ty={:?}", user_ty);
 817                 (def_id, self.typeck_results().node_substs(expr.hir_id), user_ty)
 818             }
 819         };
 820         let ty = self.tcx().mk_fn_def(def_id, substs);
 821         Expr { temp_lifetime, ty, span, kind: ExprKind::ZstLiteral { user_ty } }
 822     }
 823
 824     fn convert_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) -> ArmId {
 825         let arm = Arm {
 826             pattern: self.pattern_from_hir(&arm.pat),
 827             guard: arm.guard.as_ref().map(|g| match g {
 828                 hir::Guard::If(ref e) => Guard::If(self.mirror_expr(e)),
 829                 hir::Guard::IfLet(ref l) => {
 830                     Guard::IfLet(self.pattern_from_hir(l.pat), self.mirror_expr(l.init))
 831                 }
 832             }),
 833             body: self.mirror_expr(arm.body),
 834             lint_level: LintLevel::Explicit(arm.hir_id),
 835             scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
 836             span: arm.span,
 837         };
 838         self.thir.arms.push(arm)
 839     }
 840
 841     fn convert_path_expr(&mut self, expr: &'tcx hir::Expr<'tcx>, res: Res) -> ExprKind<'tcx> {
 842         let substs = self.typeck_results().node_substs(expr.hir_id);
 843         match res {
 844             // A regular function, constructor function or a constant.
 845             Res::Def(DefKind::Fn, _)
 846             | Res::Def(DefKind::AssocFn, _)
 847             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 848             | Res::SelfCtor(_) => {
 849                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 850                 ExprKind::ZstLiteral { user_ty }
 851             }
 852
 853             Res::Def(DefKind::ConstParam, def_id) => {
 854                 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
 855                 let item_id = self.tcx.hir().get_parent_node(hir_id);
 856                 let item_def_id = self.tcx.hir().local_def_id(item_id);
 857                 let generics = self.tcx.generics_of(item_def_id);
 858                 let index = generics.param_def_id_to_index[&def_id];
 859                 let name = self.tcx.hir().name(hir_id);
 860                 let param = ty::ParamConst::new(index, name);
 861
 862                 ExprKind::ConstParam { param, def_id }
 863             }
 864
 865             Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => {
 866                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 867                 ExprKind::NamedConst { def_id, substs, user_ty }
 868             }
 869
 870             Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
 871                 let user_provided_types = self.typeck_results.user_provided_types();
 872                 let user_ty = user_provided_types.get(expr.hir_id).copied().map(Box::new);
 873                 debug!("convert_path_expr: user_ty={:?}", user_ty);
 874                 let ty = self.typeck_results().node_type(expr.hir_id);
 875                 match ty.kind() {
 876                     // A unit struct/variant which is used as a value.
 877                     // We return a completely different ExprKind here to account for this special case.
 878                     ty::Adt(adt_def, substs) => ExprKind::Adt(Box::new(AdtExpr {
 879                         adt_def: *adt_def,
 880                         variant_index: adt_def.variant_index_with_ctor_id(def_id),
 881                         substs,
 882                         user_ty,
 883                         fields: Box::new([]),
 884                         base: None,
 885                     })),
 886                     _ => bug!("unexpected ty: {:?}", ty),
 887                 }
 888             }
 889
 890             // We encode uses of statics as a `*&STATIC` where the `&STATIC` part is
 891             // a constant reference (or constant raw pointer for `static mut`) in MIR
 892             Res::Def(DefKind::Static(_), id) => {
 893                 let ty = self.tcx.static_ptr_ty(id);
 894                 let temp_lifetime = self
 895                     .rvalue_scopes
 896                     .temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 897                 let kind = if self.tcx.is_thread_local_static(id) {
 898                     ExprKind::ThreadLocalRef(id)
 899                 } else {
 900                     let alloc_id = self.tcx.create_static_alloc(id);
 901                     ExprKind::StaticRef { alloc_id, ty, def_id: id }
 902                 };
 903                 ExprKind::Deref {
 904                     arg: self.thir.exprs.push(Expr { ty, temp_lifetime, span: expr.span, kind }),
 905                 }
 906             }
 907
 908             Res::Local(var_hir_id) => self.convert_var(var_hir_id),
 909
 910             _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
 911         }
 912     }
 913
 914     fn convert_var(&mut self, var_hir_id: hir::HirId) -> ExprKind<'tcx> {
 915         // We want upvars here not captures.
 916         // Captures will be handled in MIR.
 917         let is_upvar = self
 918             .tcx
 919             .upvars_mentioned(self.body_owner)
 920             .map_or(false, |upvars| upvars.contains_key(&var_hir_id));
 921
 922         debug!(
 923             "convert_var({:?}): is_upvar={}, body_owner={:?}",
 924             var_hir_id, is_upvar, self.body_owner
 925         );
 926
 927         if is_upvar {
 928             ExprKind::UpvarRef {
 929                 closure_def_id: self.body_owner,
 930                 var_hir_id: LocalVarId(var_hir_id),
 931             }
 932         } else {
 933             ExprKind::VarRef { id: LocalVarId(var_hir_id) }
 934         }
 935     }
 936
 937     fn overloaded_operator(
 938         &mut self,
 939         expr: &'tcx hir::Expr<'tcx>,
 940         args: Box<[ExprId]>,
 941     ) -> ExprKind<'tcx> {
 942         let fun = self.method_callee(expr, expr.span, None);
 943         let fun = self.thir.exprs.push(fun);
 944         ExprKind::Call {
 945             ty: self.thir[fun].ty,
 946             fun,
 947             args,
 948             from_hir_call: false,
 949             fn_span: expr.span,
 950         }
 951     }
 952
 953     fn overloaded_place(
 954         &mut self,
 955         expr: &'tcx hir::Expr<'tcx>,
 956         place_ty: Ty<'tcx>,
 957         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 958         args: Box<[ExprId]>,
 959         span: Span,
 960     ) -> ExprKind<'tcx> {
 961         // For an overloaded *x or x[y] expression of type T, the method
 962         // call returns an &T and we must add the deref so that the types
 963         // line up (this is because `*x` and `x[y]` represent places):
 964
 965         // Reconstruct the output assuming it's a reference with the
 966         // same region and mutability as the receiver. This holds for
 967         // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
 968         let ty::Ref(region, _, mutbl) = *self.thir[args[0]].ty.kind() else {
 969             span_bug!(span, "overloaded_place: receiver is not a reference");
 970         };
 971         let ref_ty = self.tcx.mk_ref(region, ty::TypeAndMut { ty: place_ty, mutbl });
 972
 973         // construct the complete expression `foo()` for the overloaded call,
 974         // which will yield the &T type
 975         let temp_lifetime =
 976             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 977         let fun = self.method_callee(expr, span, overloaded_callee);
 978         let fun = self.thir.exprs.push(fun);
 979         let fun_ty = self.thir[fun].ty;
 980         let ref_expr = self.thir.exprs.push(Expr {
 981             temp_lifetime,
 982             ty: ref_ty,
 983             span,
 984             kind: ExprKind::Call { ty: fun_ty, fun, args, from_hir_call: false, fn_span: span },
 985         });
 986
 987         // construct and return a deref wrapper `*foo()`
 988         ExprKind::Deref { arg: ref_expr }
 989     }
 990
 991     fn convert_captured_hir_place(
 992         &mut self,
 993         closure_expr: &'tcx hir::Expr<'tcx>,
 994         place: HirPlace<'tcx>,
 995     ) -> Expr<'tcx> {
 996         let temp_lifetime = self
 997             .rvalue_scopes
 998             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
 999         let var_ty = place.base_ty;
1000
1001         // The result of capture analysis in `rustc_typeck/check/upvar.rs`represents a captured path
1002         // as it's seen for use within the closure and not at the time of closure creation.
1003         //
1004         // That is we see expect to see it start from a captured upvar and not something that is local
1005         // to the closure's parent.
1006         let var_hir_id = match place.base {
1007             HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id,
1008             base => bug!("Expected an upvar, found {:?}", base),
1009         };
1010
1011         let mut captured_place_expr = Expr {
1012             temp_lifetime,
1013             ty: var_ty,
1014             span: closure_expr.span,
1015             kind: self.convert_var(var_hir_id),
1016         };
1017
1018         for proj in place.projections.iter() {
1019             let kind = match proj.kind {
1020                 HirProjectionKind::Deref => {
1021                     ExprKind::Deref { arg: self.thir.exprs.push(captured_place_expr) }
1022                 }
1023                 HirProjectionKind::Field(field, variant_index) => ExprKind::Field {
1024                     lhs: self.thir.exprs.push(captured_place_expr),
1025                     variant_index,
1026                     name: Field::new(field as usize),
1027                 },
1028                 HirProjectionKind::Index | HirProjectionKind::Subslice => {
1029                     // We don't capture these projections, so we can ignore them here
1030                     continue;
1031                 }
1032             };
1033
1034             captured_place_expr =
1035                 Expr { temp_lifetime, ty: proj.ty, span: closure_expr.span, kind };
1036         }
1037
1038         captured_place_expr
1039     }
1040
1041     fn capture_upvar(
1042         &mut self,
1043         closure_expr: &'tcx hir::Expr<'tcx>,
1044         captured_place: &'tcx ty::CapturedPlace<'tcx>,
1045         upvar_ty: Ty<'tcx>,
1046     ) -> Expr<'tcx> {
1047         let upvar_capture = captured_place.info.capture_kind;
1048         let captured_place_expr =
1049             self.convert_captured_hir_place(closure_expr, captured_place.place.clone());
1050         let temp_lifetime = self
1051             .rvalue_scopes
1052             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
1053
1054         match upvar_capture {
1055             ty::UpvarCapture::ByValue => captured_place_expr,
1056             ty::UpvarCapture::ByRef(upvar_borrow) => {
1057                 let borrow_kind = match upvar_borrow {
1058                     ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1059                     ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1060                     ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false },
1061                 };
1062                 Expr {
1063                     temp_lifetime,
1064                     ty: upvar_ty,
1065                     span: closure_expr.span,
1066                     kind: ExprKind::Borrow {
1067                         borrow_kind,
1068                         arg: self.thir.exprs.push(captured_place_expr),
1069                     },
1070                 }
1071             }
1072         }
1073     }
1074
1075     /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExpr.
1076     fn field_refs(&mut self, fields: &'tcx [hir::ExprField<'tcx>]) -> Box<[FieldExpr]> {
1077         fields
1078             .iter()
1079             .map(|field| FieldExpr {
1080                 name: Field::new(self.tcx.field_index(field.hir_id, self.typeck_results)),
1081                 expr: self.mirror_expr(field.expr),
1082             })
1083             .collect()
1084     }
1085 }
1086
1087 trait ToBorrowKind {
1088     fn to_borrow_kind(&self) -> BorrowKind;
1089 }
1090
1091 impl ToBorrowKind for AutoBorrowMutability {
1092     fn to_borrow_kind(&self) -> BorrowKind {
1093         use rustc_middle::ty::adjustment::AllowTwoPhase;
1094         match *self {
1095             AutoBorrowMutability::Mut { allow_two_phase_borrow } => BorrowKind::Mut {
1096                 allow_two_phase_borrow: match allow_two_phase_borrow {
1097                     AllowTwoPhase::Yes => true,
1098                     AllowTwoPhase::No => false,
1099                 },
1100             },
1101             AutoBorrowMutability::Not => BorrowKind::Shared,
1102         }
1103     }
1104 }
1105
1106 impl ToBorrowKind for hir::Mutability {
1107     fn to_borrow_kind(&self) -> BorrowKind {
1108         match *self {
1109             hir::Mutability::Mut => BorrowKind::Mut { allow_two_phase_borrow: false },
1110             hir::Mutability::Not => BorrowKind::Shared,
1111         }
1112     }
1113 }
1114
1115 fn bin_op(op: hir::BinOpKind) -> BinOp {
1116     match op {
1117         hir::BinOpKind::Add => BinOp::Add,
1118         hir::BinOpKind::Sub => BinOp::Sub,
1119         hir::BinOpKind::Mul => BinOp::Mul,
1120         hir::BinOpKind::Div => BinOp::Div,
1121         hir::BinOpKind::Rem => BinOp::Rem,
1122         hir::BinOpKind::BitXor => BinOp::BitXor,
1123         hir::BinOpKind::BitAnd => BinOp::BitAnd,
1124         hir::BinOpKind::BitOr => BinOp::BitOr,
1125         hir::BinOpKind::Shl => BinOp::Shl,
1126         hir::BinOpKind::Shr => BinOp::Shr,
1127         hir::BinOpKind::Eq => BinOp::Eq,
1128         hir::BinOpKind::Lt => BinOp::Lt,
1129         hir::BinOpKind::Le => BinOp::Le,
1130         hir::BinOpKind::Ne => BinOp::Ne,
1131         hir::BinOpKind::Ge => BinOp::Ge,
1132         hir::BinOpKind::Gt => BinOp::Gt,
1133         _ => bug!("no equivalent for ast binop {:?}", op),
1134     }
1135 }