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         // Now apply adjustments, if any.
  52         for adjustment in self.typeck_results.expr_adjustments(hir_expr) {
  53             trace!(?expr, ?adjustment);
  54             let span = expr.span;
  55             expr =
  56                 self.apply_adjustment(hir_expr, expr, adjustment, adjustment_span.unwrap_or(span));
  57         }
  58
  59         // Next, wrap this up in the expr's scope.
  60         expr = Expr {
  61             temp_lifetime,
  62             ty: expr.ty,
  63             span: hir_expr.span,
  64             kind: ExprKind::Scope {
  65                 region_scope: expr_scope,
  66                 value: self.thir.exprs.push(expr),
  67                 lint_level: LintLevel::Explicit(hir_expr.hir_id),
  68             },
  69         };
  70
  71         // Finally, create a destruction scope, if any.
  72         if let Some(region_scope) =
  73             self.region_scope_tree.opt_destruction_scope(hir_expr.hir_id.local_id)
  74         {
  75             expr = Expr {
  76                 temp_lifetime,
  77                 ty: expr.ty,
  78                 span: hir_expr.span,
  79                 kind: ExprKind::Scope {
  80                     region_scope,
  81                     value: self.thir.exprs.push(expr),
  82                     lint_level: LintLevel::Inherited,
  83                 },
  84             };
  85         }
  86
  87         // OK, all done!
  88         self.thir.exprs.push(expr)
  89     }
  90
  91     fn apply_adjustment(
  92         &mut self,
  93         hir_expr: &'tcx hir::Expr<'tcx>,
  94         mut expr: Expr<'tcx>,
  95         adjustment: &Adjustment<'tcx>,
  96         mut span: Span,
  97     ) -> Expr<'tcx> {
  98         let Expr { temp_lifetime, .. } = expr;
  99
 100         // Adjust the span from the block, to the last expression of the
 101         // block. This is a better span when returning a mutable reference
 102         // with too short a lifetime. The error message will use the span
 103         // from the assignment to the return place, which should only point
 104         // at the returned value, not the entire function body.
 105         //
 106         // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
 107         //      x
 108         //   // ^ error message points at this expression.
 109         // }
 110         let mut adjust_span = |expr: &mut Expr<'tcx>| {
 111             if let ExprKind::Block { block } = expr.kind {
 112                 if let Some(last_expr) = self.thir[block].expr {
 113                     span = self.thir[last_expr].span;
 114                     expr.span = span;
 115                 }
 116             }
 117         };
 118
 119         let kind = match adjustment.kind {
 120             Adjust::Pointer(PointerCast::Unsize) => {
 121                 adjust_span(&mut expr);
 122                 ExprKind::Pointer { cast: PointerCast::Unsize, source: self.thir.exprs.push(expr) }
 123             }
 124             Adjust::Pointer(cast) => ExprKind::Pointer { cast, source: self.thir.exprs.push(expr) },
 125             Adjust::NeverToAny => ExprKind::NeverToAny { source: self.thir.exprs.push(expr) },
 126             Adjust::Deref(None) => {
 127                 adjust_span(&mut expr);
 128                 ExprKind::Deref { arg: self.thir.exprs.push(expr) }
 129             }
 130             Adjust::Deref(Some(deref)) => {
 131                 // We don't need to do call adjust_span here since
 132                 // deref coercions always start with a built-in deref.
 133                 let call = deref.method_call(self.tcx(), expr.ty);
 134
 135                 expr = Expr {
 136                     temp_lifetime,
 137                     ty: self
 138                         .tcx
 139                         .mk_ref(deref.region, ty::TypeAndMut { ty: expr.ty, mutbl: deref.mutbl }),
 140                     span,
 141                     kind: ExprKind::Borrow {
 142                         borrow_kind: deref.mutbl.to_borrow_kind(),
 143                         arg: self.thir.exprs.push(expr),
 144                     },
 145                 };
 146
 147                 let expr = Box::new([self.thir.exprs.push(expr)]);
 148
 149                 self.overloaded_place(hir_expr, adjustment.target, Some(call), expr, deref.span)
 150             }
 151             Adjust::Borrow(AutoBorrow::Ref(_, m)) => ExprKind::Borrow {
 152                 borrow_kind: m.to_borrow_kind(),
 153                 arg: self.thir.exprs.push(expr),
 154             },
 155             Adjust::Borrow(AutoBorrow::RawPtr(mutability)) => {
 156                 ExprKind::AddressOf { mutability, arg: self.thir.exprs.push(expr) }
 157             }
 158         };
 159
 160         Expr { temp_lifetime, ty: adjustment.target, span, kind }
 161     }
 162
 163     /// Lowers a cast expression.
 164     ///
 165     /// Dealing with user type annotations is left to the caller.
 166     fn mirror_expr_cast(
 167         &mut self,
 168         source: &'tcx hir::Expr<'tcx>,
 169         temp_lifetime: Option<Scope>,
 170         span: Span,
 171     ) -> ExprKind<'tcx> {
 172         let tcx = self.tcx;
 173
 174         // Check to see if this cast is a "coercion cast", where the cast is actually done
 175         // using a coercion (or is a no-op).
 176         if self.typeck_results().is_coercion_cast(source.hir_id) {
 177             // Convert the lexpr to a vexpr.
 178             ExprKind::Use { source: self.mirror_expr(source) }
 179         } else if self.typeck_results().expr_ty(source).is_region_ptr() {
 180             // Special cased so that we can type check that the element
 181             // type of the source matches the pointed to type of the
 182             // destination.
 183             ExprKind::Pointer {
 184                 source: self.mirror_expr(source),
 185                 cast: PointerCast::ArrayToPointer,
 186             }
 187         } else {
 188             // check whether this is casting an enum variant discriminant
 189             // to prevent cycles, we refer to the discriminant initializer
 190             // which is always an integer and thus doesn't need to know the
 191             // enum's layout (or its tag type) to compute it during const eval
 192             // Example:
 193             // enum Foo {
 194             //     A,
 195             //     B = A as isize + 4,
 196             // }
 197             // The correct solution would be to add symbolic computations to miri,
 198             // so we wouldn't have to compute and store the actual value
 199
 200             let hir::ExprKind::Path(ref qpath) = source.kind else {
 201                 return ExprKind::Cast { source: self.mirror_expr(source)};
 202             };
 203
 204             let res = self.typeck_results().qpath_res(qpath, source.hir_id);
 205             let ty = self.typeck_results().node_type(source.hir_id);
 206             let ty::Adt(adt_def, substs) = ty.kind() else {
 207                 return ExprKind::Cast { source: self.mirror_expr(source)};
 208             };
 209
 210             let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), variant_ctor_id) = res else {
 211                 return ExprKind::Cast { source: self.mirror_expr(source)};
 212             };
 213
 214             let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
 215             let (discr_did, discr_offset) = adt_def.discriminant_def_for_variant(idx);
 216
 217             use rustc_middle::ty::util::IntTypeExt;
 218             let ty = adt_def.repr().discr_type();
 219             let discr_ty = ty.to_ty(tcx);
 220
 221             let param_env_ty = self.param_env.and(discr_ty);
 222             let size = tcx
 223                 .layout_of(param_env_ty)
 224                 .unwrap_or_else(|e| {
 225                     panic!("could not compute layout for {:?}: {:?}", param_env_ty, e)
 226                 })
 227                 .size;
 228
 229             let lit = ScalarInt::try_from_uint(discr_offset as u128, size).unwrap();
 230             let kind = ExprKind::NonHirLiteral { lit, user_ty: None };
 231             let offset = self.thir.exprs.push(Expr { temp_lifetime, ty: discr_ty, span, kind });
 232
 233             let source = match discr_did {
 234                 // in case we are offsetting from a computed discriminant
 235                 // and not the beginning of discriminants (which is always `0`)
 236                 Some(did) => {
 237                     let kind = ExprKind::NamedConst { def_id: did, substs, user_ty: None };
 238                     let lhs =
 239                         self.thir.exprs.push(Expr { temp_lifetime, ty: discr_ty, span, kind });
 240                     let bin = ExprKind::Binary { op: BinOp::Add, lhs, rhs: offset };
 241                     self.thir.exprs.push(Expr {
 242                         temp_lifetime,
 243                         ty: discr_ty,
 244                         span: span,
 245                         kind: bin,
 246                     })
 247                 }
 248                 None => offset,
 249             };
 250
 251             ExprKind::Cast { source }
 252         }
 253     }
 254
 255     fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx> {
 256         let tcx = self.tcx;
 257         let expr_ty = self.typeck_results().expr_ty(expr);
 258         let expr_span = expr.span;
 259         let temp_lifetime =
 260             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 261
 262         let kind = match expr.kind {
 263             // Here comes the interesting stuff:
 264             hir::ExprKind::MethodCall(segment, ref args, fn_span) => {
 265                 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
 266                 let expr = self.method_callee(expr, segment.ident.span, None);
 267                 // When we apply adjustments to the receiver, use the span of
 268                 // the overall method call for better diagnostics. args[0]
 269                 // is guaranteed to exist, since a method call always has a receiver.
 270                 let old_adjustment_span = self.adjustment_span.replace((args[0].hir_id, expr_span));
 271                 tracing::info!("Using method span: {:?}", expr.span);
 272                 let args = self.mirror_exprs(args);
 273                 self.adjustment_span = old_adjustment_span;
 274                 ExprKind::Call {
 275                     ty: expr.ty,
 276                     fun: self.thir.exprs.push(expr),
 277                     args,
 278                     from_hir_call: true,
 279                     fn_span,
 280                 }
 281             }
 282
 283             hir::ExprKind::Call(ref fun, ref args) => {
 284                 if self.typeck_results().is_method_call(expr) {
 285                     // The callee is something implementing Fn, FnMut, or FnOnce.
 286                     // Find the actual method implementation being called and
 287                     // build the appropriate UFCS call expression with the
 288                     // callee-object as expr parameter.
 289
 290                     // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
 291
 292                     let method = self.method_callee(expr, fun.span, None);
 293
 294                     let arg_tys = args.iter().map(|e| self.typeck_results().expr_ty_adjusted(e));
 295                     let tupled_args = Expr {
 296                         ty: tcx.mk_tup(arg_tys),
 297                         temp_lifetime,
 298                         span: expr.span,
 299                         kind: ExprKind::Tuple { fields: self.mirror_exprs(args) },
 300                     };
 301                     let tupled_args = self.thir.exprs.push(tupled_args);
 302
 303                     ExprKind::Call {
 304                         ty: method.ty,
 305                         fun: self.thir.exprs.push(method),
 306                         args: Box::new([self.mirror_expr(fun), tupled_args]),
 307                         from_hir_call: true,
 308                         fn_span: expr.span,
 309                     }
 310                 } else {
 311                     let adt_data =
 312                         if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = fun.kind {
 313                             // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
 314                             expr_ty.ty_adt_def().and_then(|adt_def| match path.res {
 315                                 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) => {
 316                                     Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id)))
 317                                 }
 318                                 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
 319                                 _ => None,
 320                             })
 321                         } else {
 322                             None
 323                         };
 324                     if let Some((adt_def, index)) = adt_data {
 325                         let substs = self.typeck_results().node_substs(fun.hir_id);
 326                         let user_provided_types = self.typeck_results().user_provided_types();
 327                         let user_ty =
 328                             user_provided_types.get(fun.hir_id).copied().map(|mut u_ty| {
 329                                 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
 330                                     *did = adt_def.did();
 331                                 }
 332                                 Box::new(u_ty)
 333                             });
 334                         debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
 335
 336                         let field_refs = args
 337                             .iter()
 338                             .enumerate()
 339                             .map(|(idx, e)| FieldExpr {
 340                                 name: Field::new(idx),
 341                                 expr: self.mirror_expr(e),
 342                             })
 343                             .collect();
 344                         ExprKind::Adt(Box::new(AdtExpr {
 345                             adt_def,
 346                             substs,
 347                             variant_index: index,
 348                             fields: field_refs,
 349                             user_ty,
 350                             base: None,
 351                         }))
 352                     } else {
 353                         ExprKind::Call {
 354                             ty: self.typeck_results().node_type(fun.hir_id),
 355                             fun: self.mirror_expr(fun),
 356                             args: self.mirror_exprs(args),
 357                             from_hir_call: true,
 358                             fn_span: expr.span,
 359                         }
 360                     }
 361                 }
 362             }
 363
 364             hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, ref arg) => {
 365                 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: self.mirror_expr(arg) }
 366             }
 367
 368             hir::ExprKind::AddrOf(hir::BorrowKind::Raw, mutability, ref arg) => {
 369                 ExprKind::AddressOf { mutability, arg: self.mirror_expr(arg) }
 370             }
 371
 372             hir::ExprKind::Block(ref blk, _) => ExprKind::Block { block: self.mirror_block(blk) },
 373
 374             hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
 375                 ExprKind::Assign { lhs: self.mirror_expr(lhs), rhs: self.mirror_expr(rhs) }
 376             }
 377
 378             hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
 379                 if self.typeck_results().is_method_call(expr) {
 380                     let lhs = self.mirror_expr(lhs);
 381                     let rhs = self.mirror_expr(rhs);
 382                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 383                 } else {
 384                     ExprKind::AssignOp {
 385                         op: bin_op(op.node),
 386                         lhs: self.mirror_expr(lhs),
 387                         rhs: self.mirror_expr(rhs),
 388                     }
 389                 }
 390             }
 391
 392             hir::ExprKind::Lit(ref lit) => ExprKind::Literal { lit, neg: false },
 393
 394             hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
 395                 if self.typeck_results().is_method_call(expr) {
 396                     let lhs = self.mirror_expr(lhs);
 397                     let rhs = self.mirror_expr(rhs);
 398                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 399                 } else {
 400                     // FIXME overflow
 401                     match op.node {
 402                         hir::BinOpKind::And => ExprKind::LogicalOp {
 403                             op: LogicalOp::And,
 404                             lhs: self.mirror_expr(lhs),
 405                             rhs: self.mirror_expr(rhs),
 406                         },
 407                         hir::BinOpKind::Or => ExprKind::LogicalOp {
 408                             op: LogicalOp::Or,
 409                             lhs: self.mirror_expr(lhs),
 410                             rhs: self.mirror_expr(rhs),
 411                         },
 412                         _ => {
 413                             let op = bin_op(op.node);
 414                             ExprKind::Binary {
 415                                 op,
 416                                 lhs: self.mirror_expr(lhs),
 417                                 rhs: self.mirror_expr(rhs),
 418                             }
 419                         }
 420                     }
 421                 }
 422             }
 423
 424             hir::ExprKind::Index(ref lhs, ref index) => {
 425                 if self.typeck_results().is_method_call(expr) {
 426                     let lhs = self.mirror_expr(lhs);
 427                     let index = self.mirror_expr(index);
 428                     self.overloaded_place(expr, expr_ty, None, Box::new([lhs, index]), expr.span)
 429                 } else {
 430                     ExprKind::Index { lhs: self.mirror_expr(lhs), index: self.mirror_expr(index) }
 431                 }
 432             }
 433
 434             hir::ExprKind::Unary(hir::UnOp::Deref, ref arg) => {
 435                 if self.typeck_results().is_method_call(expr) {
 436                     let arg = self.mirror_expr(arg);
 437                     self.overloaded_place(expr, expr_ty, None, Box::new([arg]), expr.span)
 438                 } else {
 439                     ExprKind::Deref { arg: self.mirror_expr(arg) }
 440                 }
 441             }
 442
 443             hir::ExprKind::Unary(hir::UnOp::Not, ref arg) => {
 444                 if self.typeck_results().is_method_call(expr) {
 445                     let arg = self.mirror_expr(arg);
 446                     self.overloaded_operator(expr, Box::new([arg]))
 447                 } else {
 448                     ExprKind::Unary { op: UnOp::Not, arg: self.mirror_expr(arg) }
 449                 }
 450             }
 451
 452             hir::ExprKind::Unary(hir::UnOp::Neg, ref arg) => {
 453                 if self.typeck_results().is_method_call(expr) {
 454                     let arg = self.mirror_expr(arg);
 455                     self.overloaded_operator(expr, Box::new([arg]))
 456                 } else if let hir::ExprKind::Lit(ref lit) = arg.kind {
 457                     ExprKind::Literal { lit, neg: true }
 458                 } else {
 459                     ExprKind::Unary { op: UnOp::Neg, arg: self.mirror_expr(arg) }
 460                 }
 461             }
 462
 463             hir::ExprKind::Struct(ref qpath, ref fields, ref base) => match expr_ty.kind() {
 464                 ty::Adt(adt, substs) => match adt.adt_kind() {
 465                     AdtKind::Struct | AdtKind::Union => {
 466                         let user_provided_types = self.typeck_results().user_provided_types();
 467                         let user_ty = user_provided_types.get(expr.hir_id).copied().map(Box::new);
 468                         debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
 469                         ExprKind::Adt(Box::new(AdtExpr {
 470                             adt_def: *adt,
 471                             variant_index: VariantIdx::new(0),
 472                             substs,
 473                             user_ty,
 474                             fields: self.field_refs(fields),
 475                             base: base.as_ref().map(|base| FruInfo {
 476                                 base: self.mirror_expr(base),
 477                                 field_types: self.typeck_results().fru_field_types()[expr.hir_id]
 478                                     .iter()
 479                                     .copied()
 480                                     .collect(),
 481                             }),
 482                         }))
 483                     }
 484                     AdtKind::Enum => {
 485                         let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 486                         match res {
 487                             Res::Def(DefKind::Variant, variant_id) => {
 488                                 assert!(base.is_none());
 489
 490                                 let index = adt.variant_index_with_id(variant_id);
 491                                 let user_provided_types =
 492                                     self.typeck_results().user_provided_types();
 493                                 let user_ty =
 494                                     user_provided_types.get(expr.hir_id).copied().map(Box::new);
 495                                 debug!("make_mirror_unadjusted: (variant) user_ty={:?}", user_ty);
 496                                 ExprKind::Adt(Box::new(AdtExpr {
 497                                     adt_def: *adt,
 498                                     variant_index: index,
 499                                     substs,
 500                                     user_ty,
 501                                     fields: self.field_refs(fields),
 502                                     base: None,
 503                                 }))
 504                             }
 505                             _ => {
 506                                 span_bug!(expr.span, "unexpected res: {:?}", res);
 507                             }
 508                         }
 509                     }
 510                 },
 511                 _ => {
 512                     span_bug!(expr.span, "unexpected type for struct literal: {:?}", expr_ty);
 513                 }
 514             },
 515
 516             hir::ExprKind::Closure { .. } => {
 517                 let closure_ty = self.typeck_results().expr_ty(expr);
 518                 let (def_id, substs, movability) = match *closure_ty.kind() {
 519                     ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
 520                     ty::Generator(def_id, substs, movability) => {
 521                         (def_id, UpvarSubsts::Generator(substs), Some(movability))
 522                     }
 523                     _ => {
 524                         span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
 525                     }
 526                 };
 527                 let def_id = def_id.expect_local();
 528
 529                 let upvars = self
 530                     .typeck_results
 531                     .closure_min_captures_flattened(def_id)
 532                     .zip(substs.upvar_tys())
 533                     .map(|(captured_place, ty)| {
 534                         let upvars = self.capture_upvar(expr, captured_place, ty);
 535                         self.thir.exprs.push(upvars)
 536                     })
 537                     .collect();
 538
 539                 // Convert the closure fake reads, if any, from hir `Place` to ExprRef
 540                 let fake_reads = match self.typeck_results.closure_fake_reads.get(&def_id) {
 541                     Some(fake_reads) => fake_reads
 542                         .iter()
 543                         .map(|(place, cause, hir_id)| {
 544                             let expr = self.convert_captured_hir_place(expr, place.clone());
 545                             (self.thir.exprs.push(expr), *cause, *hir_id)
 546                         })
 547                         .collect(),
 548                     None => Vec::new(),
 549                 };
 550
 551                 ExprKind::Closure(Box::new(ClosureExpr {
 552                     closure_id: def_id,
 553                     substs,
 554                     upvars,
 555                     movability,
 556                     fake_reads,
 557                 }))
 558             }
 559
 560             hir::ExprKind::Path(ref qpath) => {
 561                 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 562                 self.convert_path_expr(expr, res)
 563             }
 564
 565             hir::ExprKind::InlineAsm(ref asm) => ExprKind::InlineAsm(Box::new(InlineAsmExpr {
 566                 template: asm.template,
 567                 operands: asm
 568                     .operands
 569                     .iter()
 570                     .map(|(op, _op_sp)| match *op {
 571                         hir::InlineAsmOperand::In { reg, ref expr } => {
 572                             InlineAsmOperand::In { reg, expr: self.mirror_expr(expr) }
 573                         }
 574                         hir::InlineAsmOperand::Out { reg, late, ref expr } => {
 575                             InlineAsmOperand::Out {
 576                                 reg,
 577                                 late,
 578                                 expr: expr.as_ref().map(|expr| self.mirror_expr(expr)),
 579                             }
 580                         }
 581                         hir::InlineAsmOperand::InOut { reg, late, ref expr } => {
 582                             InlineAsmOperand::InOut { reg, late, expr: self.mirror_expr(expr) }
 583                         }
 584                         hir::InlineAsmOperand::SplitInOut {
 585                             reg,
 586                             late,
 587                             ref in_expr,
 588                             ref out_expr,
 589                         } => InlineAsmOperand::SplitInOut {
 590                             reg,
 591                             late,
 592                             in_expr: self.mirror_expr(in_expr),
 593                             out_expr: out_expr.as_ref().map(|expr| self.mirror_expr(expr)),
 594                         },
 595                         hir::InlineAsmOperand::Const { ref anon_const } => {
 596                             let anon_const_def_id = tcx.hir().local_def_id(anon_const.hir_id);
 597                             let value = mir::ConstantKind::from_anon_const(
 598                                 tcx,
 599                                 anon_const_def_id,
 600                                 self.param_env,
 601                             );
 602                             let span = tcx.hir().span(anon_const.hir_id);
 603
 604                             InlineAsmOperand::Const { value, span }
 605                         }
 606                         hir::InlineAsmOperand::SymFn { ref anon_const } => {
 607                             let anon_const_def_id = tcx.hir().local_def_id(anon_const.hir_id);
 608                             let value = mir::ConstantKind::from_anon_const(
 609                                 tcx,
 610                                 anon_const_def_id,
 611                                 self.param_env,
 612                             );
 613                             let span = tcx.hir().span(anon_const.hir_id);
 614
 615                             InlineAsmOperand::SymFn { value, span }
 616                         }
 617                         hir::InlineAsmOperand::SymStatic { path: _, def_id } => {
 618                             InlineAsmOperand::SymStatic { def_id }
 619                         }
 620                     })
 621                     .collect(),
 622                 options: asm.options,
 623                 line_spans: asm.line_spans,
 624             })),
 625
 626             hir::ExprKind::ConstBlock(ref anon_const) => {
 627                 let ty = self.typeck_results().node_type(anon_const.hir_id);
 628                 let did = tcx.hir().local_def_id(anon_const.hir_id).to_def_id();
 629                 let typeck_root_def_id = tcx.typeck_root_def_id(did);
 630                 let parent_substs =
 631                     tcx.erase_regions(InternalSubsts::identity_for_item(tcx, typeck_root_def_id));
 632                 let substs =
 633                     InlineConstSubsts::new(tcx, InlineConstSubstsParts { parent_substs, ty })
 634                         .substs;
 635
 636                 ExprKind::ConstBlock { did, substs }
 637             }
 638             // Now comes the rote stuff:
 639             hir::ExprKind::Repeat(ref v, _) => {
 640                 let ty = self.typeck_results().expr_ty(expr);
 641                 let ty::Array(_, count) = ty.kind() else {
 642                     span_bug!(expr.span, "unexpected repeat expr ty: {:?}", ty);
 643                 };
 644
 645                 ExprKind::Repeat { value: self.mirror_expr(v), count: *count }
 646             }
 647             hir::ExprKind::Ret(ref v) => {
 648                 ExprKind::Return { value: v.as_ref().map(|v| self.mirror_expr(v)) }
 649             }
 650             hir::ExprKind::Break(dest, ref value) => match dest.target_id {
 651                 Ok(target_id) => ExprKind::Break {
 652                     label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node },
 653                     value: value.as_ref().map(|value| self.mirror_expr(value)),
 654                 },
 655                 Err(err) => bug!("invalid loop id for break: {}", err),
 656             },
 657             hir::ExprKind::Continue(dest) => match dest.target_id {
 658                 Ok(loop_id) => ExprKind::Continue {
 659                     label: region::Scope { id: loop_id.local_id, data: region::ScopeData::Node },
 660                 },
 661                 Err(err) => bug!("invalid loop id for continue: {}", err),
 662             },
 663             hir::ExprKind::Let(let_expr) => ExprKind::Let {
 664                 expr: self.mirror_expr(let_expr.init),
 665                 pat: self.pattern_from_hir(let_expr.pat),
 666             },
 667             hir::ExprKind::If(cond, then, else_opt) => ExprKind::If {
 668                 if_then_scope: region::Scope {
 669                     id: then.hir_id.local_id,
 670                     data: region::ScopeData::IfThen,
 671                 },
 672                 cond: self.mirror_expr(cond),
 673                 then: self.mirror_expr(then),
 674                 else_opt: else_opt.map(|el| self.mirror_expr(el)),
 675             },
 676             hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
 677                 scrutinee: self.mirror_expr(discr),
 678                 arms: arms.iter().map(|a| self.convert_arm(a)).collect(),
 679             },
 680             hir::ExprKind::Loop(ref body, ..) => {
 681                 let block_ty = self.typeck_results().node_type(body.hir_id);
 682                 let temp_lifetime = self
 683                     .rvalue_scopes
 684                     .temporary_scope(self.region_scope_tree, body.hir_id.local_id);
 685                 let block = self.mirror_block(body);
 686                 let body = self.thir.exprs.push(Expr {
 687                     ty: block_ty,
 688                     temp_lifetime,
 689                     span: self.thir[block].span,
 690                     kind: ExprKind::Block { block },
 691                 });
 692                 ExprKind::Loop { body }
 693             }
 694             hir::ExprKind::Field(ref source, ..) => ExprKind::Field {
 695                 lhs: self.mirror_expr(source),
 696                 variant_index: VariantIdx::new(0),
 697                 name: Field::new(tcx.field_index(expr.hir_id, self.typeck_results)),
 698             },
 699             hir::ExprKind::Cast(ref source, ref cast_ty) => {
 700                 // Check for a user-given type annotation on this `cast`
 701                 let user_provided_types = self.typeck_results.user_provided_types();
 702                 let user_ty = user_provided_types.get(cast_ty.hir_id);
 703
 704                 debug!(
 705                     "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
 706                     expr, cast_ty.hir_id, user_ty,
 707                 );
 708
 709                 let cast = self.mirror_expr_cast(*source, temp_lifetime, expr.span);
 710
 711                 if let Some(user_ty) = user_ty {
 712                     // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
 713                     //       inefficient, revisit this when performance becomes an issue.
 714                     let cast_expr = self.thir.exprs.push(Expr {
 715                         temp_lifetime,
 716                         ty: expr_ty,
 717                         span: expr.span,
 718                         kind: cast,
 719                     });
 720                     debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
 721
 722                     ExprKind::ValueTypeAscription {
 723                         source: cast_expr,
 724                         user_ty: Some(Box::new(*user_ty)),
 725                     }
 726                 } else {
 727                     cast
 728                 }
 729             }
 730             hir::ExprKind::Type(ref source, ref ty) => {
 731                 let user_provided_types = self.typeck_results.user_provided_types();
 732                 let user_ty = user_provided_types.get(ty.hir_id).copied().map(Box::new);
 733                 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
 734                 let mirrored = self.mirror_expr(source);
 735                 if source.is_syntactic_place_expr() {
 736                     ExprKind::PlaceTypeAscription { source: mirrored, user_ty }
 737                 } else {
 738                     ExprKind::ValueTypeAscription { source: mirrored, user_ty }
 739                 }
 740             }
 741             hir::ExprKind::DropTemps(ref source) => {
 742                 ExprKind::Use { source: self.mirror_expr(source) }
 743             }
 744             hir::ExprKind::Box(ref value) => ExprKind::Box { value: self.mirror_expr(value) },
 745             hir::ExprKind::Array(ref fields) => {
 746                 ExprKind::Array { fields: self.mirror_exprs(fields) }
 747             }
 748             hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: self.mirror_exprs(fields) },
 749
 750             hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: self.mirror_expr(v) },
 751             hir::ExprKind::Err => unreachable!(),
 752         };
 753
 754         Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
 755     }
 756
 757     fn user_substs_applied_to_res(
 758         &mut self,
 759         hir_id: hir::HirId,
 760         res: Res,
 761     ) -> Option<Box<ty::CanonicalUserType<'tcx>>> {
 762         debug!("user_substs_applied_to_res: res={:?}", res);
 763         let user_provided_type = match res {
 764             // A reference to something callable -- e.g., a fn, method, or
 765             // a tuple-struct or tuple-variant. This has the type of a
 766             // `Fn` but with the user-given substitutions.
 767             Res::Def(DefKind::Fn, _)
 768             | Res::Def(DefKind::AssocFn, _)
 769             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 770             | Res::Def(DefKind::Const, _)
 771             | Res::Def(DefKind::AssocConst, _) => {
 772                 self.typeck_results().user_provided_types().get(hir_id).copied().map(Box::new)
 773             }
 774
 775             // A unit struct/variant which is used as a value (e.g.,
 776             // `None`). This has the type of the enum/struct that defines
 777             // this variant -- but with the substitutions given by the
 778             // user.
 779             Res::Def(DefKind::Ctor(_, CtorKind::Const), _) => {
 780                 self.user_substs_applied_to_ty_of_hir_id(hir_id).map(Box::new)
 781             }
 782
 783             // `Self` is used in expression as a tuple struct constructor or a unit struct constructor
 784             Res::SelfCtor(_) => self.user_substs_applied_to_ty_of_hir_id(hir_id).map(Box::new),
 785
 786             _ => bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id),
 787         };
 788         debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
 789         user_provided_type
 790     }
 791
 792     fn method_callee(
 793         &mut self,
 794         expr: &hir::Expr<'_>,
 795         span: Span,
 796         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 797     ) -> Expr<'tcx> {
 798         let temp_lifetime =
 799             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 800         let (def_id, substs, user_ty) = match overloaded_callee {
 801             Some((def_id, substs)) => (def_id, substs, None),
 802             None => {
 803                 let (kind, def_id) =
 804                     self.typeck_results().type_dependent_def(expr.hir_id).unwrap_or_else(|| {
 805                         span_bug!(expr.span, "no type-dependent def for method callee")
 806                     });
 807                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, Res::Def(kind, def_id));
 808                 debug!("method_callee: user_ty={:?}", user_ty);
 809                 (def_id, self.typeck_results().node_substs(expr.hir_id), user_ty)
 810             }
 811         };
 812         let ty = self.tcx().mk_fn_def(def_id, substs);
 813         Expr { temp_lifetime, ty, span, kind: ExprKind::ZstLiteral { user_ty } }
 814     }
 815
 816     fn convert_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) -> ArmId {
 817         let arm = Arm {
 818             pattern: self.pattern_from_hir(&arm.pat),
 819             guard: arm.guard.as_ref().map(|g| match g {
 820                 hir::Guard::If(ref e) => Guard::If(self.mirror_expr(e)),
 821                 hir::Guard::IfLet(ref l) => {
 822                     Guard::IfLet(self.pattern_from_hir(l.pat), self.mirror_expr(l.init))
 823                 }
 824             }),
 825             body: self.mirror_expr(arm.body),
 826             lint_level: LintLevel::Explicit(arm.hir_id),
 827             scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
 828             span: arm.span,
 829         };
 830         self.thir.arms.push(arm)
 831     }
 832
 833     fn convert_path_expr(&mut self, expr: &'tcx hir::Expr<'tcx>, res: Res) -> ExprKind<'tcx> {
 834         let substs = self.typeck_results().node_substs(expr.hir_id);
 835         match res {
 836             // A regular function, constructor function or a constant.
 837             Res::Def(DefKind::Fn, _)
 838             | Res::Def(DefKind::AssocFn, _)
 839             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 840             | Res::SelfCtor(_) => {
 841                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 842                 ExprKind::ZstLiteral { user_ty }
 843             }
 844
 845             Res::Def(DefKind::ConstParam, def_id) => {
 846                 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
 847                 let item_id = self.tcx.hir().get_parent_node(hir_id);
 848                 let item_def_id = self.tcx.hir().local_def_id(item_id);
 849                 let generics = self.tcx.generics_of(item_def_id);
 850                 let index = generics.param_def_id_to_index[&def_id];
 851                 let name = self.tcx.hir().name(hir_id);
 852                 let param = ty::ParamConst::new(index, name);
 853
 854                 ExprKind::ConstParam { param, def_id }
 855             }
 856
 857             Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => {
 858                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 859                 ExprKind::NamedConst { def_id, substs, user_ty }
 860             }
 861
 862             Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
 863                 let user_provided_types = self.typeck_results.user_provided_types();
 864                 let user_ty = user_provided_types.get(expr.hir_id).copied().map(Box::new);
 865                 debug!("convert_path_expr: user_ty={:?}", user_ty);
 866                 let ty = self.typeck_results().node_type(expr.hir_id);
 867                 match ty.kind() {
 868                     // A unit struct/variant which is used as a value.
 869                     // We return a completely different ExprKind here to account for this special case.
 870                     ty::Adt(adt_def, substs) => ExprKind::Adt(Box::new(AdtExpr {
 871                         adt_def: *adt_def,
 872                         variant_index: adt_def.variant_index_with_ctor_id(def_id),
 873                         substs,
 874                         user_ty,
 875                         fields: Box::new([]),
 876                         base: None,
 877                     })),
 878                     _ => bug!("unexpected ty: {:?}", ty),
 879                 }
 880             }
 881
 882             // We encode uses of statics as a `*&STATIC` where the `&STATIC` part is
 883             // a constant reference (or constant raw pointer for `static mut`) in MIR
 884             Res::Def(DefKind::Static(_), id) => {
 885                 let ty = self.tcx.static_ptr_ty(id);
 886                 let temp_lifetime = self
 887                     .rvalue_scopes
 888                     .temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 889                 let kind = if self.tcx.is_thread_local_static(id) {
 890                     ExprKind::ThreadLocalRef(id)
 891                 } else {
 892                     let alloc_id = self.tcx.create_static_alloc(id);
 893                     ExprKind::StaticRef { alloc_id, ty, def_id: id }
 894                 };
 895                 ExprKind::Deref {
 896                     arg: self.thir.exprs.push(Expr { ty, temp_lifetime, span: expr.span, kind }),
 897                 }
 898             }
 899
 900             Res::Local(var_hir_id) => self.convert_var(var_hir_id),
 901
 902             _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
 903         }
 904     }
 905
 906     fn convert_var(&mut self, var_hir_id: hir::HirId) -> ExprKind<'tcx> {
 907         // We want upvars here not captures.
 908         // Captures will be handled in MIR.
 909         let is_upvar = self
 910             .tcx
 911             .upvars_mentioned(self.body_owner)
 912             .map_or(false, |upvars| upvars.contains_key(&var_hir_id));
 913
 914         debug!(
 915             "convert_var({:?}): is_upvar={}, body_owner={:?}",
 916             var_hir_id, is_upvar, self.body_owner
 917         );
 918
 919         if is_upvar {
 920             ExprKind::UpvarRef {
 921                 closure_def_id: self.body_owner,
 922                 var_hir_id: LocalVarId(var_hir_id),
 923             }
 924         } else {
 925             ExprKind::VarRef { id: LocalVarId(var_hir_id) }
 926         }
 927     }
 928
 929     fn overloaded_operator(
 930         &mut self,
 931         expr: &'tcx hir::Expr<'tcx>,
 932         args: Box<[ExprId]>,
 933     ) -> ExprKind<'tcx> {
 934         let fun = self.method_callee(expr, expr.span, None);
 935         let fun = self.thir.exprs.push(fun);
 936         ExprKind::Call {
 937             ty: self.thir[fun].ty,
 938             fun,
 939             args,
 940             from_hir_call: false,
 941             fn_span: expr.span,
 942         }
 943     }
 944
 945     fn overloaded_place(
 946         &mut self,
 947         expr: &'tcx hir::Expr<'tcx>,
 948         place_ty: Ty<'tcx>,
 949         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 950         args: Box<[ExprId]>,
 951         span: Span,
 952     ) -> ExprKind<'tcx> {
 953         // For an overloaded *x or x[y] expression of type T, the method
 954         // call returns an &T and we must add the deref so that the types
 955         // line up (this is because `*x` and `x[y]` represent places):
 956
 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 ty::Ref(region, _, mutbl) = *self.thir[args[0]].ty.kind() else {
 961             span_bug!(span, "overloaded_place: receiver is not a reference");
 962         };
 963         let ref_ty = self.tcx.mk_ref(region, ty::TypeAndMut { ty: place_ty, mutbl });
 964
 965         // construct the complete expression `foo()` for the overloaded call,
 966         // which will yield the &T type
 967         let temp_lifetime =
 968             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 969         let fun = self.method_callee(expr, span, overloaded_callee);
 970         let fun = self.thir.exprs.push(fun);
 971         let fun_ty = self.thir[fun].ty;
 972         let ref_expr = self.thir.exprs.push(Expr {
 973             temp_lifetime,
 974             ty: ref_ty,
 975             span,
 976             kind: ExprKind::Call { ty: fun_ty, fun, args, from_hir_call: false, fn_span: span },
 977         });
 978
 979         // construct and return a deref wrapper `*foo()`
 980         ExprKind::Deref { arg: ref_expr }
 981     }
 982
 983     fn convert_captured_hir_place(
 984         &mut self,
 985         closure_expr: &'tcx hir::Expr<'tcx>,
 986         place: HirPlace<'tcx>,
 987     ) -> Expr<'tcx> {
 988         let temp_lifetime = self
 989             .rvalue_scopes
 990             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
 991         let var_ty = place.base_ty;
 992
 993         // The result of capture analysis in `rustc_typeck/check/upvar.rs`represents a captured path
 994         // as it's seen for use within the closure and not at the time of closure creation.
 995         //
 996         // That is we see expect to see it start from a captured upvar and not something that is local
 997         // to the closure's parent.
 998         let var_hir_id = match place.base {
 999             HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id,
1000             base => bug!("Expected an upvar, found {:?}", base),
1001         };
1002
1003         let mut captured_place_expr = Expr {
1004             temp_lifetime,
1005             ty: var_ty,
1006             span: closure_expr.span,
1007             kind: self.convert_var(var_hir_id),
1008         };
1009
1010         for proj in place.projections.iter() {
1011             let kind = match proj.kind {
1012                 HirProjectionKind::Deref => {
1013                     ExprKind::Deref { arg: self.thir.exprs.push(captured_place_expr) }
1014                 }
1015                 HirProjectionKind::Field(field, variant_index) => ExprKind::Field {
1016                     lhs: self.thir.exprs.push(captured_place_expr),
1017                     variant_index,
1018                     name: Field::new(field as usize),
1019                 },
1020                 HirProjectionKind::Index | HirProjectionKind::Subslice => {
1021                     // We don't capture these projections, so we can ignore them here
1022                     continue;
1023                 }
1024             };
1025
1026             captured_place_expr =
1027                 Expr { temp_lifetime, ty: proj.ty, span: closure_expr.span, kind };
1028         }
1029
1030         captured_place_expr
1031     }
1032
1033     fn capture_upvar(
1034         &mut self,
1035         closure_expr: &'tcx hir::Expr<'tcx>,
1036         captured_place: &'tcx ty::CapturedPlace<'tcx>,
1037         upvar_ty: Ty<'tcx>,
1038     ) -> Expr<'tcx> {
1039         let upvar_capture = captured_place.info.capture_kind;
1040         let captured_place_expr =
1041             self.convert_captured_hir_place(closure_expr, captured_place.place.clone());
1042         let temp_lifetime = self
1043             .rvalue_scopes
1044             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
1045
1046         match upvar_capture {
1047             ty::UpvarCapture::ByValue => captured_place_expr,
1048             ty::UpvarCapture::ByRef(upvar_borrow) => {
1049                 let borrow_kind = match upvar_borrow {
1050                     ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1051                     ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1052                     ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false },
1053                 };
1054                 Expr {
1055                     temp_lifetime,
1056                     ty: upvar_ty,
1057                     span: closure_expr.span,
1058                     kind: ExprKind::Borrow {
1059                         borrow_kind,
1060                         arg: self.thir.exprs.push(captured_place_expr),
1061                     },
1062                 }
1063             }
1064         }
1065     }
1066
1067     /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExpr.
1068     fn field_refs(&mut self, fields: &'tcx [hir::ExprField<'tcx>]) -> Box<[FieldExpr]> {
1069         fields
1070             .iter()
1071             .map(|field| FieldExpr {
1072                 name: Field::new(self.tcx.field_index(field.hir_id, self.typeck_results)),
1073                 expr: self.mirror_expr(field.expr),
1074             })
1075             .collect()
1076     }
1077 }
1078
1079 trait ToBorrowKind {
1080     fn to_borrow_kind(&self) -> BorrowKind;
1081 }
1082
1083 impl ToBorrowKind for AutoBorrowMutability {
1084     fn to_borrow_kind(&self) -> BorrowKind {
1085         use rustc_middle::ty::adjustment::AllowTwoPhase;
1086         match *self {
1087             AutoBorrowMutability::Mut { allow_two_phase_borrow } => BorrowKind::Mut {
1088                 allow_two_phase_borrow: match allow_two_phase_borrow {
1089                     AllowTwoPhase::Yes => true,
1090                     AllowTwoPhase::No => false,
1091                 },
1092             },
1093             AutoBorrowMutability::Not => BorrowKind::Shared,
1094         }
1095     }
1096 }
1097
1098 impl ToBorrowKind for hir::Mutability {
1099     fn to_borrow_kind(&self) -> BorrowKind {
1100         match *self {
1101             hir::Mutability::Mut => BorrowKind::Mut { allow_two_phase_borrow: false },
1102             hir::Mutability::Not => BorrowKind::Shared,
1103         }
1104     }
1105 }
1106
1107 fn bin_op(op: hir::BinOpKind) -> BinOp {
1108     match op {
1109         hir::BinOpKind::Add => BinOp::Add,
1110         hir::BinOpKind::Sub => BinOp::Sub,
1111         hir::BinOpKind::Mul => BinOp::Mul,
1112         hir::BinOpKind::Div => BinOp::Div,
1113         hir::BinOpKind::Rem => BinOp::Rem,
1114         hir::BinOpKind::BitXor => BinOp::BitXor,
1115         hir::BinOpKind::BitAnd => BinOp::BitAnd,
1116         hir::BinOpKind::BitOr => BinOp::BitOr,
1117         hir::BinOpKind::Shl => BinOp::Shl,
1118         hir::BinOpKind::Shr => BinOp::Shr,
1119         hir::BinOpKind::Eq => BinOp::Eq,
1120         hir::BinOpKind::Lt => BinOp::Lt,
1121         hir::BinOpKind::Le => BinOp::Le,
1122         hir::BinOpKind::Ne => BinOp::Ne,
1123         hir::BinOpKind::Ge => BinOp::Ge,
1124         hir::BinOpKind::Gt => BinOp::Gt,
1125         _ => bug!("no equivalent for ast binop {:?}", op),
1126     }
1127 }