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, receiver, 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 =
 271                     self.adjustment_span.replace((receiver.hir_id, expr_span));
 272                 info!("Using method span: {:?}", expr.span);
 273                 let args = std::iter::once(receiver)
 274                     .chain(args.iter())
 275                     .map(|expr| self.mirror_expr(expr))
 276                     .collect();
 277                 self.adjustment_span = old_adjustment_span;
 278                 ExprKind::Call {
 279                     ty: expr.ty,
 280                     fun: self.thir.exprs.push(expr),
 281                     args,
 282                     from_hir_call: true,
 283                     fn_span,
 284                 }
 285             }
 286
 287             hir::ExprKind::Call(ref fun, ref args) => {
 288                 if self.typeck_results().is_method_call(expr) {
 289                     // The callee is something implementing Fn, FnMut, or FnOnce.
 290                     // Find the actual method implementation being called and
 291                     // build the appropriate UFCS call expression with the
 292                     // callee-object as expr parameter.
 293
 294                     // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
 295
 296                     let method = self.method_callee(expr, fun.span, None);
 297
 298                     let arg_tys = args.iter().map(|e| self.typeck_results().expr_ty_adjusted(e));
 299                     let tupled_args = Expr {
 300                         ty: tcx.mk_tup(arg_tys),
 301                         temp_lifetime,
 302                         span: expr.span,
 303                         kind: ExprKind::Tuple { fields: self.mirror_exprs(args) },
 304                     };
 305                     let tupled_args = self.thir.exprs.push(tupled_args);
 306
 307                     ExprKind::Call {
 308                         ty: method.ty,
 309                         fun: self.thir.exprs.push(method),
 310                         args: Box::new([self.mirror_expr(fun), tupled_args]),
 311                         from_hir_call: true,
 312                         fn_span: expr.span,
 313                     }
 314                 } else {
 315                     let adt_data =
 316                         if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = fun.kind {
 317                             // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
 318                             expr_ty.ty_adt_def().and_then(|adt_def| match path.res {
 319                                 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) => {
 320                                     Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id)))
 321                                 }
 322                                 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
 323                                 _ => None,
 324                             })
 325                         } else {
 326                             None
 327                         };
 328                     if let Some((adt_def, index)) = adt_data {
 329                         let substs = self.typeck_results().node_substs(fun.hir_id);
 330                         let user_provided_types = self.typeck_results().user_provided_types();
 331                         let user_ty =
 332                             user_provided_types.get(fun.hir_id).copied().map(|mut u_ty| {
 333                                 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
 334                                     *did = adt_def.did();
 335                                 }
 336                                 Box::new(u_ty)
 337                             });
 338                         debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
 339
 340                         let field_refs = args
 341                             .iter()
 342                             .enumerate()
 343                             .map(|(idx, e)| FieldExpr {
 344                                 name: Field::new(idx),
 345                                 expr: self.mirror_expr(e),
 346                             })
 347                             .collect();
 348                         ExprKind::Adt(Box::new(AdtExpr {
 349                             adt_def,
 350                             substs,
 351                             variant_index: index,
 352                             fields: field_refs,
 353                             user_ty,
 354                             base: None,
 355                         }))
 356                     } else {
 357                         ExprKind::Call {
 358                             ty: self.typeck_results().node_type(fun.hir_id),
 359                             fun: self.mirror_expr(fun),
 360                             args: self.mirror_exprs(args),
 361                             from_hir_call: true,
 362                             fn_span: expr.span,
 363                         }
 364                     }
 365                 }
 366             }
 367
 368             hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, ref arg) => {
 369                 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: self.mirror_expr(arg) }
 370             }
 371
 372             hir::ExprKind::AddrOf(hir::BorrowKind::Raw, mutability, ref arg) => {
 373                 ExprKind::AddressOf { mutability, arg: self.mirror_expr(arg) }
 374             }
 375
 376             hir::ExprKind::Block(ref blk, _) => ExprKind::Block { block: self.mirror_block(blk) },
 377
 378             hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
 379                 ExprKind::Assign { lhs: self.mirror_expr(lhs), rhs: self.mirror_expr(rhs) }
 380             }
 381
 382             hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
 383                 if self.typeck_results().is_method_call(expr) {
 384                     let lhs = self.mirror_expr(lhs);
 385                     let rhs = self.mirror_expr(rhs);
 386                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 387                 } else {
 388                     ExprKind::AssignOp {
 389                         op: bin_op(op.node),
 390                         lhs: self.mirror_expr(lhs),
 391                         rhs: self.mirror_expr(rhs),
 392                     }
 393                 }
 394             }
 395
 396             hir::ExprKind::Lit(ref lit) => ExprKind::Literal { lit, neg: false },
 397
 398             hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
 399                 if self.typeck_results().is_method_call(expr) {
 400                     let lhs = self.mirror_expr(lhs);
 401                     let rhs = self.mirror_expr(rhs);
 402                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 403                 } else {
 404                     // FIXME overflow
 405                     match op.node {
 406                         hir::BinOpKind::And => ExprKind::LogicalOp {
 407                             op: LogicalOp::And,
 408                             lhs: self.mirror_expr(lhs),
 409                             rhs: self.mirror_expr(rhs),
 410                         },
 411                         hir::BinOpKind::Or => ExprKind::LogicalOp {
 412                             op: LogicalOp::Or,
 413                             lhs: self.mirror_expr(lhs),
 414                             rhs: self.mirror_expr(rhs),
 415                         },
 416                         _ => {
 417                             let op = bin_op(op.node);
 418                             ExprKind::Binary {
 419                                 op,
 420                                 lhs: self.mirror_expr(lhs),
 421                                 rhs: self.mirror_expr(rhs),
 422                             }
 423                         }
 424                     }
 425                 }
 426             }
 427
 428             hir::ExprKind::Index(ref lhs, ref index) => {
 429                 if self.typeck_results().is_method_call(expr) {
 430                     let lhs = self.mirror_expr(lhs);
 431                     let index = self.mirror_expr(index);
 432                     self.overloaded_place(expr, expr_ty, None, Box::new([lhs, index]), expr.span)
 433                 } else {
 434                     ExprKind::Index { lhs: self.mirror_expr(lhs), index: self.mirror_expr(index) }
 435                 }
 436             }
 437
 438             hir::ExprKind::Unary(hir::UnOp::Deref, ref arg) => {
 439                 if self.typeck_results().is_method_call(expr) {
 440                     let arg = self.mirror_expr(arg);
 441                     self.overloaded_place(expr, expr_ty, None, Box::new([arg]), expr.span)
 442                 } else {
 443                     ExprKind::Deref { arg: self.mirror_expr(arg) }
 444                 }
 445             }
 446
 447             hir::ExprKind::Unary(hir::UnOp::Not, ref arg) => {
 448                 if self.typeck_results().is_method_call(expr) {
 449                     let arg = self.mirror_expr(arg);
 450                     self.overloaded_operator(expr, Box::new([arg]))
 451                 } else {
 452                     ExprKind::Unary { op: UnOp::Not, arg: self.mirror_expr(arg) }
 453                 }
 454             }
 455
 456             hir::ExprKind::Unary(hir::UnOp::Neg, ref arg) => {
 457                 if self.typeck_results().is_method_call(expr) {
 458                     let arg = self.mirror_expr(arg);
 459                     self.overloaded_operator(expr, Box::new([arg]))
 460                 } else if let hir::ExprKind::Lit(ref lit) = arg.kind {
 461                     ExprKind::Literal { lit, neg: true }
 462                 } else {
 463                     ExprKind::Unary { op: UnOp::Neg, arg: self.mirror_expr(arg) }
 464                 }
 465             }
 466
 467             hir::ExprKind::Struct(ref qpath, ref fields, ref base) => match expr_ty.kind() {
 468                 ty::Adt(adt, substs) => match adt.adt_kind() {
 469                     AdtKind::Struct | AdtKind::Union => {
 470                         let user_provided_types = self.typeck_results().user_provided_types();
 471                         let user_ty = user_provided_types.get(expr.hir_id).copied().map(Box::new);
 472                         debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
 473                         ExprKind::Adt(Box::new(AdtExpr {
 474                             adt_def: *adt,
 475                             variant_index: VariantIdx::new(0),
 476                             substs,
 477                             user_ty,
 478                             fields: self.field_refs(fields),
 479                             base: base.as_ref().map(|base| FruInfo {
 480                                 base: self.mirror_expr(base),
 481                                 field_types: self.typeck_results().fru_field_types()[expr.hir_id]
 482                                     .iter()
 483                                     .copied()
 484                                     .collect(),
 485                             }),
 486                         }))
 487                     }
 488                     AdtKind::Enum => {
 489                         let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 490                         match res {
 491                             Res::Def(DefKind::Variant, variant_id) => {
 492                                 assert!(base.is_none());
 493
 494                                 let index = adt.variant_index_with_id(variant_id);
 495                                 let user_provided_types =
 496                                     self.typeck_results().user_provided_types();
 497                                 let user_ty =
 498                                     user_provided_types.get(expr.hir_id).copied().map(Box::new);
 499                                 debug!("make_mirror_unadjusted: (variant) user_ty={:?}", user_ty);
 500                                 ExprKind::Adt(Box::new(AdtExpr {
 501                                     adt_def: *adt,
 502                                     variant_index: index,
 503                                     substs,
 504                                     user_ty,
 505                                     fields: self.field_refs(fields),
 506                                     base: None,
 507                                 }))
 508                             }
 509                             _ => {
 510                                 span_bug!(expr.span, "unexpected res: {:?}", res);
 511                             }
 512                         }
 513                     }
 514                 },
 515                 _ => {
 516                     span_bug!(expr.span, "unexpected type for struct literal: {:?}", expr_ty);
 517                 }
 518             },
 519
 520             hir::ExprKind::Closure { .. } => {
 521                 let closure_ty = self.typeck_results().expr_ty(expr);
 522                 let (def_id, substs, movability) = match *closure_ty.kind() {
 523                     ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
 524                     ty::Generator(def_id, substs, movability) => {
 525                         (def_id, UpvarSubsts::Generator(substs), Some(movability))
 526                     }
 527                     _ => {
 528                         span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
 529                     }
 530                 };
 531                 let def_id = def_id.expect_local();
 532
 533                 let upvars = self
 534                     .typeck_results
 535                     .closure_min_captures_flattened(def_id)
 536                     .zip(substs.upvar_tys())
 537                     .map(|(captured_place, ty)| {
 538                         let upvars = self.capture_upvar(expr, captured_place, ty);
 539                         self.thir.exprs.push(upvars)
 540                     })
 541                     .collect();
 542
 543                 // Convert the closure fake reads, if any, from hir `Place` to ExprRef
 544                 let fake_reads = match self.typeck_results.closure_fake_reads.get(&def_id) {
 545                     Some(fake_reads) => fake_reads
 546                         .iter()
 547                         .map(|(place, cause, hir_id)| {
 548                             let expr = self.convert_captured_hir_place(expr, place.clone());
 549                             (self.thir.exprs.push(expr), *cause, *hir_id)
 550                         })
 551                         .collect(),
 552                     None => Vec::new(),
 553                 };
 554
 555                 ExprKind::Closure(Box::new(ClosureExpr {
 556                     closure_id: def_id,
 557                     substs,
 558                     upvars,
 559                     movability,
 560                     fake_reads,
 561                 }))
 562             }
 563
 564             hir::ExprKind::Path(ref qpath) => {
 565                 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 566                 self.convert_path_expr(expr, res)
 567             }
 568
 569             hir::ExprKind::InlineAsm(ref asm) => ExprKind::InlineAsm(Box::new(InlineAsmExpr {
 570                 template: asm.template,
 571                 operands: asm
 572                     .operands
 573                     .iter()
 574                     .map(|(op, _op_sp)| match *op {
 575                         hir::InlineAsmOperand::In { reg, ref expr } => {
 576                             InlineAsmOperand::In { reg, expr: self.mirror_expr(expr) }
 577                         }
 578                         hir::InlineAsmOperand::Out { reg, late, ref expr } => {
 579                             InlineAsmOperand::Out {
 580                                 reg,
 581                                 late,
 582                                 expr: expr.as_ref().map(|expr| self.mirror_expr(expr)),
 583                             }
 584                         }
 585                         hir::InlineAsmOperand::InOut { reg, late, ref expr } => {
 586                             InlineAsmOperand::InOut { reg, late, expr: self.mirror_expr(expr) }
 587                         }
 588                         hir::InlineAsmOperand::SplitInOut {
 589                             reg,
 590                             late,
 591                             ref in_expr,
 592                             ref out_expr,
 593                         } => InlineAsmOperand::SplitInOut {
 594                             reg,
 595                             late,
 596                             in_expr: self.mirror_expr(in_expr),
 597                             out_expr: out_expr.as_ref().map(|expr| self.mirror_expr(expr)),
 598                         },
 599                         hir::InlineAsmOperand::Const { ref anon_const } => {
 600                             let anon_const_def_id = tcx.hir().local_def_id(anon_const.hir_id);
 601                             let value = mir::ConstantKind::from_anon_const(
 602                                 tcx,
 603                                 anon_const_def_id,
 604                                 self.param_env,
 605                             );
 606                             let span = tcx.hir().span(anon_const.hir_id);
 607
 608                             InlineAsmOperand::Const { value, span }
 609                         }
 610                         hir::InlineAsmOperand::SymFn { ref anon_const } => {
 611                             let anon_const_def_id = tcx.hir().local_def_id(anon_const.hir_id);
 612                             let value = mir::ConstantKind::from_anon_const(
 613                                 tcx,
 614                                 anon_const_def_id,
 615                                 self.param_env,
 616                             );
 617                             let span = tcx.hir().span(anon_const.hir_id);
 618
 619                             InlineAsmOperand::SymFn { value, span }
 620                         }
 621                         hir::InlineAsmOperand::SymStatic { path: _, def_id } => {
 622                             InlineAsmOperand::SymStatic { def_id }
 623                         }
 624                     })
 625                     .collect(),
 626                 options: asm.options,
 627                 line_spans: asm.line_spans,
 628             })),
 629
 630             hir::ExprKind::ConstBlock(ref anon_const) => {
 631                 let ty = self.typeck_results().node_type(anon_const.hir_id);
 632                 let did = tcx.hir().local_def_id(anon_const.hir_id).to_def_id();
 633                 let typeck_root_def_id = tcx.typeck_root_def_id(did);
 634                 let parent_substs =
 635                     tcx.erase_regions(InternalSubsts::identity_for_item(tcx, typeck_root_def_id));
 636                 let substs =
 637                     InlineConstSubsts::new(tcx, InlineConstSubstsParts { parent_substs, ty })
 638                         .substs;
 639
 640                 ExprKind::ConstBlock { did, substs }
 641             }
 642             // Now comes the rote stuff:
 643             hir::ExprKind::Repeat(ref v, _) => {
 644                 let ty = self.typeck_results().expr_ty(expr);
 645                 let ty::Array(_, count) = ty.kind() else {
 646                     span_bug!(expr.span, "unexpected repeat expr ty: {:?}", ty);
 647                 };
 648
 649                 ExprKind::Repeat { value: self.mirror_expr(v), count: *count }
 650             }
 651             hir::ExprKind::Ret(ref v) => {
 652                 ExprKind::Return { value: v.as_ref().map(|v| self.mirror_expr(v)) }
 653             }
 654             hir::ExprKind::Break(dest, ref value) => match dest.target_id {
 655                 Ok(target_id) => ExprKind::Break {
 656                     label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node },
 657                     value: value.as_ref().map(|value| self.mirror_expr(value)),
 658                 },
 659                 Err(err) => bug!("invalid loop id for break: {}", err),
 660             },
 661             hir::ExprKind::Continue(dest) => match dest.target_id {
 662                 Ok(loop_id) => ExprKind::Continue {
 663                     label: region::Scope { id: loop_id.local_id, data: region::ScopeData::Node },
 664                 },
 665                 Err(err) => bug!("invalid loop id for continue: {}", err),
 666             },
 667             hir::ExprKind::Let(let_expr) => ExprKind::Let {
 668                 expr: self.mirror_expr(let_expr.init),
 669                 pat: self.pattern_from_hir(let_expr.pat),
 670             },
 671             hir::ExprKind::If(cond, then, else_opt) => ExprKind::If {
 672                 if_then_scope: region::Scope {
 673                     id: then.hir_id.local_id,
 674                     data: region::ScopeData::IfThen,
 675                 },
 676                 cond: self.mirror_expr(cond),
 677                 then: self.mirror_expr(then),
 678                 else_opt: else_opt.map(|el| self.mirror_expr(el)),
 679             },
 680             hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
 681                 scrutinee: self.mirror_expr(discr),
 682                 arms: arms.iter().map(|a| self.convert_arm(a)).collect(),
 683             },
 684             hir::ExprKind::Loop(ref body, ..) => {
 685                 let block_ty = self.typeck_results().node_type(body.hir_id);
 686                 let temp_lifetime = self
 687                     .rvalue_scopes
 688                     .temporary_scope(self.region_scope_tree, body.hir_id.local_id);
 689                 let block = self.mirror_block(body);
 690                 let body = self.thir.exprs.push(Expr {
 691                     ty: block_ty,
 692                     temp_lifetime,
 693                     span: self.thir[block].span,
 694                     kind: ExprKind::Block { block },
 695                 });
 696                 ExprKind::Loop { body }
 697             }
 698             hir::ExprKind::Field(ref source, ..) => ExprKind::Field {
 699                 lhs: self.mirror_expr(source),
 700                 variant_index: VariantIdx::new(0),
 701                 name: Field::new(tcx.field_index(expr.hir_id, self.typeck_results)),
 702             },
 703             hir::ExprKind::Cast(ref source, ref cast_ty) => {
 704                 // Check for a user-given type annotation on this `cast`
 705                 let user_provided_types = self.typeck_results.user_provided_types();
 706                 let user_ty = user_provided_types.get(cast_ty.hir_id);
 707
 708                 debug!(
 709                     "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
 710                     expr, cast_ty.hir_id, user_ty,
 711                 );
 712
 713                 let cast = self.mirror_expr_cast(*source, temp_lifetime, expr.span);
 714
 715                 if let Some(user_ty) = user_ty {
 716                     // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
 717                     //       inefficient, revisit this when performance becomes an issue.
 718                     let cast_expr = self.thir.exprs.push(Expr {
 719                         temp_lifetime,
 720                         ty: expr_ty,
 721                         span: expr.span,
 722                         kind: cast,
 723                     });
 724                     debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
 725
 726                     ExprKind::ValueTypeAscription {
 727                         source: cast_expr,
 728                         user_ty: Some(Box::new(*user_ty)),
 729                     }
 730                 } else {
 731                     cast
 732                 }
 733             }
 734             hir::ExprKind::Type(ref source, ref ty) => {
 735                 let user_provided_types = self.typeck_results.user_provided_types();
 736                 let user_ty = user_provided_types.get(ty.hir_id).copied().map(Box::new);
 737                 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
 738                 let mirrored = self.mirror_expr(source);
 739                 if source.is_syntactic_place_expr() {
 740                     ExprKind::PlaceTypeAscription { source: mirrored, user_ty }
 741                 } else {
 742                     ExprKind::ValueTypeAscription { source: mirrored, user_ty }
 743                 }
 744             }
 745             hir::ExprKind::DropTemps(ref source) => {
 746                 ExprKind::Use { source: self.mirror_expr(source) }
 747             }
 748             hir::ExprKind::Box(ref value) => ExprKind::Box { value: self.mirror_expr(value) },
 749             hir::ExprKind::Array(ref fields) => {
 750                 ExprKind::Array { fields: self.mirror_exprs(fields) }
 751             }
 752             hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: self.mirror_exprs(fields) },
 753
 754             hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: self.mirror_expr(v) },
 755             hir::ExprKind::Err => unreachable!(),
 756         };
 757
 758         Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
 759     }
 760
 761     fn user_substs_applied_to_res(
 762         &mut self,
 763         hir_id: hir::HirId,
 764         res: Res,
 765     ) -> Option<Box<ty::CanonicalUserType<'tcx>>> {
 766         debug!("user_substs_applied_to_res: res={:?}", res);
 767         let user_provided_type = match res {
 768             // A reference to something callable -- e.g., a fn, method, or
 769             // a tuple-struct or tuple-variant. This has the type of a
 770             // `Fn` but with the user-given substitutions.
 771             Res::Def(DefKind::Fn, _)
 772             | Res::Def(DefKind::AssocFn, _)
 773             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 774             | Res::Def(DefKind::Const, _)
 775             | Res::Def(DefKind::AssocConst, _) => {
 776                 self.typeck_results().user_provided_types().get(hir_id).copied().map(Box::new)
 777             }
 778
 779             // A unit struct/variant which is used as a value (e.g.,
 780             // `None`). This has the type of the enum/struct that defines
 781             // this variant -- but with the substitutions given by the
 782             // user.
 783             Res::Def(DefKind::Ctor(_, CtorKind::Const), _) => {
 784                 self.user_substs_applied_to_ty_of_hir_id(hir_id).map(Box::new)
 785             }
 786
 787             // `Self` is used in expression as a tuple struct constructor or a unit struct constructor
 788             Res::SelfCtor(_) => self.user_substs_applied_to_ty_of_hir_id(hir_id).map(Box::new),
 789
 790             _ => bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id),
 791         };
 792         debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
 793         user_provided_type
 794     }
 795
 796     fn method_callee(
 797         &mut self,
 798         expr: &hir::Expr<'_>,
 799         span: Span,
 800         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 801     ) -> Expr<'tcx> {
 802         let temp_lifetime =
 803             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 804         let (def_id, substs, user_ty) = match overloaded_callee {
 805             Some((def_id, substs)) => (def_id, substs, None),
 806             None => {
 807                 let (kind, def_id) =
 808                     self.typeck_results().type_dependent_def(expr.hir_id).unwrap_or_else(|| {
 809                         span_bug!(expr.span, "no type-dependent def for method callee")
 810                     });
 811                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, Res::Def(kind, def_id));
 812                 debug!("method_callee: user_ty={:?}", user_ty);
 813                 (def_id, self.typeck_results().node_substs(expr.hir_id), user_ty)
 814             }
 815         };
 816         let ty = self.tcx().mk_fn_def(def_id, substs);
 817         Expr { temp_lifetime, ty, span, kind: ExprKind::ZstLiteral { user_ty } }
 818     }
 819
 820     fn convert_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) -> ArmId {
 821         let arm = Arm {
 822             pattern: self.pattern_from_hir(&arm.pat),
 823             guard: arm.guard.as_ref().map(|g| match g {
 824                 hir::Guard::If(ref e) => Guard::If(self.mirror_expr(e)),
 825                 hir::Guard::IfLet(ref l) => {
 826                     Guard::IfLet(self.pattern_from_hir(l.pat), self.mirror_expr(l.init))
 827                 }
 828             }),
 829             body: self.mirror_expr(arm.body),
 830             lint_level: LintLevel::Explicit(arm.hir_id),
 831             scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
 832             span: arm.span,
 833         };
 834         self.thir.arms.push(arm)
 835     }
 836
 837     fn convert_path_expr(&mut self, expr: &'tcx hir::Expr<'tcx>, res: Res) -> ExprKind<'tcx> {
 838         let substs = self.typeck_results().node_substs(expr.hir_id);
 839         match res {
 840             // A regular function, constructor function or a constant.
 841             Res::Def(DefKind::Fn, _)
 842             | Res::Def(DefKind::AssocFn, _)
 843             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 844             | Res::SelfCtor(_) => {
 845                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 846                 ExprKind::ZstLiteral { user_ty }
 847             }
 848
 849             Res::Def(DefKind::ConstParam, def_id) => {
 850                 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
 851                 let item_id = self.tcx.hir().get_parent_node(hir_id);
 852                 let item_def_id = self.tcx.hir().local_def_id(item_id);
 853                 let generics = self.tcx.generics_of(item_def_id);
 854                 let index = generics.param_def_id_to_index[&def_id];
 855                 let name = self.tcx.hir().name(hir_id);
 856                 let param = ty::ParamConst::new(index, name);
 857
 858                 ExprKind::ConstParam { param, def_id }
 859             }
 860
 861             Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => {
 862                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 863                 ExprKind::NamedConst { def_id, substs, user_ty }
 864             }
 865
 866             Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
 867                 let user_provided_types = self.typeck_results.user_provided_types();
 868                 let user_ty = user_provided_types.get(expr.hir_id).copied().map(Box::new);
 869                 debug!("convert_path_expr: user_ty={:?}", user_ty);
 870                 let ty = self.typeck_results().node_type(expr.hir_id);
 871                 match ty.kind() {
 872                     // A unit struct/variant which is used as a value.
 873                     // We return a completely different ExprKind here to account for this special case.
 874                     ty::Adt(adt_def, substs) => ExprKind::Adt(Box::new(AdtExpr {
 875                         adt_def: *adt_def,
 876                         variant_index: adt_def.variant_index_with_ctor_id(def_id),
 877                         substs,
 878                         user_ty,
 879                         fields: Box::new([]),
 880                         base: None,
 881                     })),
 882                     _ => bug!("unexpected ty: {:?}", ty),
 883                 }
 884             }
 885
 886             // We encode uses of statics as a `*&STATIC` where the `&STATIC` part is
 887             // a constant reference (or constant raw pointer for `static mut`) in MIR
 888             Res::Def(DefKind::Static(_), id) => {
 889                 let ty = self.tcx.static_ptr_ty(id);
 890                 let temp_lifetime = self
 891                     .rvalue_scopes
 892                     .temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 893                 let kind = if self.tcx.is_thread_local_static(id) {
 894                     ExprKind::ThreadLocalRef(id)
 895                 } else {
 896                     let alloc_id = self.tcx.create_static_alloc(id);
 897                     ExprKind::StaticRef { alloc_id, ty, def_id: id }
 898                 };
 899                 ExprKind::Deref {
 900                     arg: self.thir.exprs.push(Expr { ty, temp_lifetime, span: expr.span, kind }),
 901                 }
 902             }
 903
 904             Res::Local(var_hir_id) => self.convert_var(var_hir_id),
 905
 906             _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
 907         }
 908     }
 909
 910     fn convert_var(&mut self, var_hir_id: hir::HirId) -> ExprKind<'tcx> {
 911         // We want upvars here not captures.
 912         // Captures will be handled in MIR.
 913         let is_upvar = self
 914             .tcx
 915             .upvars_mentioned(self.body_owner)
 916             .map_or(false, |upvars| upvars.contains_key(&var_hir_id));
 917
 918         debug!(
 919             "convert_var({:?}): is_upvar={}, body_owner={:?}",
 920             var_hir_id, is_upvar, self.body_owner
 921         );
 922
 923         if is_upvar {
 924             ExprKind::UpvarRef {
 925                 closure_def_id: self.body_owner,
 926                 var_hir_id: LocalVarId(var_hir_id),
 927             }
 928         } else {
 929             ExprKind::VarRef { id: LocalVarId(var_hir_id) }
 930         }
 931     }
 932
 933     fn overloaded_operator(
 934         &mut self,
 935         expr: &'tcx hir::Expr<'tcx>,
 936         args: Box<[ExprId]>,
 937     ) -> ExprKind<'tcx> {
 938         let fun = self.method_callee(expr, expr.span, None);
 939         let fun = self.thir.exprs.push(fun);
 940         ExprKind::Call {
 941             ty: self.thir[fun].ty,
 942             fun,
 943             args,
 944             from_hir_call: false,
 945             fn_span: expr.span,
 946         }
 947     }
 948
 949     fn overloaded_place(
 950         &mut self,
 951         expr: &'tcx hir::Expr<'tcx>,
 952         place_ty: Ty<'tcx>,
 953         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 954         args: Box<[ExprId]>,
 955         span: Span,
 956     ) -> ExprKind<'tcx> {
 957         // For an overloaded *x or x[y] expression of type T, the method
 958         // call returns an &T and we must add the deref so that the types
 959         // line up (this is because `*x` and `x[y]` represent places):
 960
 961         // Reconstruct the output assuming it's a reference with the
 962         // same region and mutability as the receiver. This holds for
 963         // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
 964         let ty::Ref(region, _, mutbl) = *self.thir[args[0]].ty.kind() else {
 965             span_bug!(span, "overloaded_place: receiver is not a reference");
 966         };
 967         let ref_ty = self.tcx.mk_ref(region, ty::TypeAndMut { ty: place_ty, mutbl });
 968
 969         // construct the complete expression `foo()` for the overloaded call,
 970         // which will yield the &T type
 971         let temp_lifetime =
 972             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 973         let fun = self.method_callee(expr, span, overloaded_callee);
 974         let fun = self.thir.exprs.push(fun);
 975         let fun_ty = self.thir[fun].ty;
 976         let ref_expr = self.thir.exprs.push(Expr {
 977             temp_lifetime,
 978             ty: ref_ty,
 979             span,
 980             kind: ExprKind::Call { ty: fun_ty, fun, args, from_hir_call: false, fn_span: span },
 981         });
 982
 983         // construct and return a deref wrapper `*foo()`
 984         ExprKind::Deref { arg: ref_expr }
 985     }
 986
 987     fn convert_captured_hir_place(
 988         &mut self,
 989         closure_expr: &'tcx hir::Expr<'tcx>,
 990         place: HirPlace<'tcx>,
 991     ) -> Expr<'tcx> {
 992         let temp_lifetime = self
 993             .rvalue_scopes
 994             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
 995         let var_ty = place.base_ty;
 996
 997         // The result of capture analysis in `rustc_typeck/check/upvar.rs`represents a captured path
 998         // as it's seen for use within the closure and not at the time of closure creation.
 999         //
1000         // That is we see expect to see it start from a captured upvar and not something that is local
1001         // to the closure's parent.
1002         let var_hir_id = match place.base {
1003             HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id,
1004             base => bug!("Expected an upvar, found {:?}", base),
1005         };
1006
1007         let mut captured_place_expr = Expr {
1008             temp_lifetime,
1009             ty: var_ty,
1010             span: closure_expr.span,
1011             kind: self.convert_var(var_hir_id),
1012         };
1013
1014         for proj in place.projections.iter() {
1015             let kind = match proj.kind {
1016                 HirProjectionKind::Deref => {
1017                     ExprKind::Deref { arg: self.thir.exprs.push(captured_place_expr) }
1018                 }
1019                 HirProjectionKind::Field(field, variant_index) => ExprKind::Field {
1020                     lhs: self.thir.exprs.push(captured_place_expr),
1021                     variant_index,
1022                     name: Field::new(field as usize),
1023                 },
1024                 HirProjectionKind::Index | HirProjectionKind::Subslice => {
1025                     // We don't capture these projections, so we can ignore them here
1026                     continue;
1027                 }
1028             };
1029
1030             captured_place_expr =
1031                 Expr { temp_lifetime, ty: proj.ty, span: closure_expr.span, kind };
1032         }
1033
1034         captured_place_expr
1035     }
1036
1037     fn capture_upvar(
1038         &mut self,
1039         closure_expr: &'tcx hir::Expr<'tcx>,
1040         captured_place: &'tcx ty::CapturedPlace<'tcx>,
1041         upvar_ty: Ty<'tcx>,
1042     ) -> Expr<'tcx> {
1043         let upvar_capture = captured_place.info.capture_kind;
1044         let captured_place_expr =
1045             self.convert_captured_hir_place(closure_expr, captured_place.place.clone());
1046         let temp_lifetime = self
1047             .rvalue_scopes
1048             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
1049
1050         match upvar_capture {
1051             ty::UpvarCapture::ByValue => captured_place_expr,
1052             ty::UpvarCapture::ByRef(upvar_borrow) => {
1053                 let borrow_kind = match upvar_borrow {
1054                     ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1055                     ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1056                     ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false },
1057                 };
1058                 Expr {
1059                     temp_lifetime,
1060                     ty: upvar_ty,
1061                     span: closure_expr.span,
1062                     kind: ExprKind::Borrow {
1063                         borrow_kind,
1064                         arg: self.thir.exprs.push(captured_place_expr),
1065                     },
1066                 }
1067             }
1068         }
1069     }
1070
1071     /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExpr.
1072     fn field_refs(&mut self, fields: &'tcx [hir::ExprField<'tcx>]) -> Box<[FieldExpr]> {
1073         fields
1074             .iter()
1075             .map(|field| FieldExpr {
1076                 name: Field::new(self.tcx.field_index(field.hir_id, self.typeck_results)),
1077                 expr: self.mirror_expr(field.expr),
1078             })
1079             .collect()
1080     }
1081 }
1082
1083 trait ToBorrowKind {
1084     fn to_borrow_kind(&self) -> BorrowKind;
1085 }
1086
1087 impl ToBorrowKind for AutoBorrowMutability {
1088     fn to_borrow_kind(&self) -> BorrowKind {
1089         use rustc_middle::ty::adjustment::AllowTwoPhase;
1090         match *self {
1091             AutoBorrowMutability::Mut { allow_two_phase_borrow } => BorrowKind::Mut {
1092                 allow_two_phase_borrow: match allow_two_phase_borrow {
1093                     AllowTwoPhase::Yes => true,
1094                     AllowTwoPhase::No => false,
1095                 },
1096             },
1097             AutoBorrowMutability::Not => BorrowKind::Shared,
1098         }
1099     }
1100 }
1101
1102 impl ToBorrowKind for hir::Mutability {
1103     fn to_borrow_kind(&self) -> BorrowKind {
1104         match *self {
1105             hir::Mutability::Mut => BorrowKind::Mut { allow_two_phase_borrow: false },
1106             hir::Mutability::Not => BorrowKind::Shared,
1107         }
1108     }
1109 }
1110
1111 fn bin_op(op: hir::BinOpKind) -> BinOp {
1112     match op {
1113         hir::BinOpKind::Add => BinOp::Add,
1114         hir::BinOpKind::Sub => BinOp::Sub,
1115         hir::BinOpKind::Mul => BinOp::Mul,
1116         hir::BinOpKind::Div => BinOp::Div,
1117         hir::BinOpKind::Rem => BinOp::Rem,
1118         hir::BinOpKind::BitXor => BinOp::BitXor,
1119         hir::BinOpKind::BitAnd => BinOp::BitAnd,
1120         hir::BinOpKind::BitOr => BinOp::BitOr,
1121         hir::BinOpKind::Shl => BinOp::Shl,
1122         hir::BinOpKind::Shr => BinOp::Shr,
1123         hir::BinOpKind::Eq => BinOp::Eq,
1124         hir::BinOpKind::Lt => BinOp::Lt,
1125         hir::BinOpKind::Le => BinOp::Le,
1126         hir::BinOpKind::Ne => BinOp::Ne,
1127         hir::BinOpKind::Ge => BinOp::Ge,
1128         hir::BinOpKind::Gt => BinOp::Gt,
1129         _ => bug!("no equivalent for ast binop {:?}", op),
1130     }
1131 }