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

   1 use crate::thir::cx::Cx;
   2 use crate::thir::util::UserAnnotatedTyHelpers;
   3 use rustc_data_structures::stack::ensure_sufficient_stack;
   4 use rustc_hir as hir;
   5 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
   6 use rustc_index::vec::Idx;
   7 use rustc_middle::hir::place::Place as HirPlace;
   8 use rustc_middle::hir::place::PlaceBase as HirPlaceBase;
   9 use rustc_middle::hir::place::ProjectionKind as HirProjectionKind;
  10 use rustc_middle::middle::region;
  11 use rustc_middle::mir::{BinOp, BorrowKind, Field, UnOp};
  12 use rustc_middle::thir::*;
  13 use rustc_middle::ty::adjustment::{
  14     Adjust, Adjustment, AutoBorrow, AutoBorrowMutability, PointerCast,
  15 };
  16 use rustc_middle::ty::subst::{InternalSubsts, SubstsRef};
  17 use rustc_middle::ty::{self, AdtKind, Ty, UpvarSubsts, UserType};
  18 use rustc_span::def_id::DefId;
  19 use rustc_span::Span;
  20 use rustc_target::abi::VariantIdx;
  21
  22 impl<'tcx> Cx<'tcx> {
  23     crate fn mirror_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) -> ExprId {
  24         // `mirror_expr` is recursing very deep. Make sure the stack doesn't overflow.
  25         ensure_sufficient_stack(|| self.mirror_expr_inner(expr))
  26     }
  27
  28     crate fn mirror_exprs(&mut self, exprs: &'tcx [hir::Expr<'tcx>]) -> Box<[ExprId]> {
  29         exprs.iter().map(|expr| self.mirror_expr_inner(expr)).collect()
  30     }
  31
  32     pub(super) fn mirror_expr_inner(&mut self, hir_expr: &'tcx hir::Expr<'tcx>) -> ExprId {
  33         let temp_lifetime = self.region_scope_tree.temporary_scope(hir_expr.hir_id.local_id);
  34         let expr_scope =
  35             region::Scope { id: hir_expr.hir_id.local_id, data: region::ScopeData::Node };
  36
  37         debug!("Expr::make_mirror(): id={}, span={:?}", hir_expr.hir_id, hir_expr.span);
  38
  39         let mut expr = self.make_mirror_unadjusted(hir_expr);
  40
  41         let adjustment_span = match self.adjustment_span {
  42             Some((hir_id, span)) if hir_id == hir_expr.hir_id => Some(span),
  43             _ => None,
  44         };
  45
  46         // Now apply adjustments, if any.
  47         for adjustment in self.typeck_results.expr_adjustments(hir_expr) {
  48             debug!("make_mirror: expr={:?} applying adjustment={:?}", expr, adjustment);
  49             let span = expr.span;
  50             expr =
  51                 self.apply_adjustment(hir_expr, expr, adjustment, adjustment_span.unwrap_or(span));
  52         }
  53
  54         // Next, wrap this up in the expr's scope.
  55         expr = Expr {
  56             temp_lifetime,
  57             ty: expr.ty,
  58             span: hir_expr.span,
  59             kind: ExprKind::Scope {
  60                 region_scope: expr_scope,
  61                 value: self.thir.exprs.push(expr),
  62                 lint_level: LintLevel::Explicit(hir_expr.hir_id),
  63             },
  64         };
  65
  66         // Finally, create a destruction scope, if any.
  67         if let Some(region_scope) =
  68             self.region_scope_tree.opt_destruction_scope(hir_expr.hir_id.local_id)
  69         {
  70             expr = Expr {
  71                 temp_lifetime,
  72                 ty: expr.ty,
  73                 span: hir_expr.span,
  74                 kind: ExprKind::Scope {
  75                     region_scope,
  76                     value: self.thir.exprs.push(expr),
  77                     lint_level: LintLevel::Inherited,
  78                 },
  79             };
  80         }
  81
  82         // OK, all done!
  83         self.thir.exprs.push(expr)
  84     }
  85
  86     fn apply_adjustment(
  87         &mut self,
  88         hir_expr: &'tcx hir::Expr<'tcx>,
  89         mut expr: Expr<'tcx>,
  90         adjustment: &Adjustment<'tcx>,
  91         mut span: Span,
  92     ) -> Expr<'tcx> {
  93         let Expr { temp_lifetime, .. } = expr;
  94
  95         // Adjust the span from the block, to the last expression of the
  96         // block. This is a better span when returning a mutable reference
  97         // with too short a lifetime. The error message will use the span
  98         // from the assignment to the return place, which should only point
  99         // at the returned value, not the entire function body.
 100         //
 101         // fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
 102         //      x
 103         //   // ^ error message points at this expression.
 104         // }
 105         let mut adjust_span = |expr: &mut Expr<'tcx>| {
 106             if let ExprKind::Block { body } = &expr.kind {
 107                 if let Some(last_expr) = body.expr {
 108                     span = self.thir[last_expr].span;
 109                     expr.span = span;
 110                 }
 111             }
 112         };
 113
 114         let kind = match adjustment.kind {
 115             Adjust::Pointer(PointerCast::Unsize) => {
 116                 adjust_span(&mut expr);
 117                 ExprKind::Pointer { cast: PointerCast::Unsize, source: self.thir.exprs.push(expr) }
 118             }
 119             Adjust::Pointer(cast) => ExprKind::Pointer { cast, source: self.thir.exprs.push(expr) },
 120             Adjust::NeverToAny => ExprKind::NeverToAny { source: self.thir.exprs.push(expr) },
 121             Adjust::Deref(None) => {
 122                 adjust_span(&mut expr);
 123                 ExprKind::Deref { arg: self.thir.exprs.push(expr) }
 124             }
 125             Adjust::Deref(Some(deref)) => {
 126                 // We don't need to do call adjust_span here since
 127                 // deref coercions always start with a built-in deref.
 128                 let call = deref.method_call(self.tcx(), expr.ty);
 129
 130                 expr = Expr {
 131                     temp_lifetime,
 132                     ty: self
 133                         .tcx
 134                         .mk_ref(deref.region, ty::TypeAndMut { ty: expr.ty, mutbl: deref.mutbl }),
 135                     span,
 136                     kind: ExprKind::Borrow {
 137                         borrow_kind: deref.mutbl.to_borrow_kind(),
 138                         arg: self.thir.exprs.push(expr),
 139                     },
 140                 };
 141
 142                 let expr = Box::new([self.thir.exprs.push(expr)]);
 143
 144                 self.overloaded_place(hir_expr, adjustment.target, Some(call), expr, deref.span)
 145             }
 146             Adjust::Borrow(AutoBorrow::Ref(_, m)) => ExprKind::Borrow {
 147                 borrow_kind: m.to_borrow_kind(),
 148                 arg: self.thir.exprs.push(expr),
 149             },
 150             Adjust::Borrow(AutoBorrow::RawPtr(mutability)) => {
 151                 ExprKind::AddressOf { mutability, arg: self.thir.exprs.push(expr) }
 152             }
 153         };
 154
 155         Expr { temp_lifetime, ty: adjustment.target, span, kind }
 156     }
 157
 158     fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx> {
 159         let expr_ty = self.typeck_results().expr_ty(expr);
 160         let expr_span = expr.span;
 161         let temp_lifetime = self.region_scope_tree.temporary_scope(expr.hir_id.local_id);
 162
 163         let kind = match expr.kind {
 164             // Here comes the interesting stuff:
 165             hir::ExprKind::MethodCall(segment, ref args, fn_span) => {
 166                 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
 167                 let expr = self.method_callee(expr, segment.ident.span, None);
 168                 // When we apply adjustments to the receiver, use the span of
 169                 // the overall method call for better diagnostics. args[0]
 170                 // is guaranteed to exist, since a method call always has a receiver.
 171                 let old_adjustment_span = self.adjustment_span.replace((args[0].hir_id, expr_span));
 172                 tracing::info!("Using method span: {:?}", expr.span);
 173                 let args = self.mirror_exprs(args);
 174                 self.adjustment_span = old_adjustment_span;
 175                 ExprKind::Call {
 176                     ty: expr.ty,
 177                     fun: self.thir.exprs.push(expr),
 178                     args,
 179                     from_hir_call: true,
 180                     fn_span,
 181                 }
 182             }
 183
 184             hir::ExprKind::Call(ref fun, ref args) => {
 185                 if self.typeck_results().is_method_call(expr) {
 186                     // The callee is something implementing Fn, FnMut, or FnOnce.
 187                     // Find the actual method implementation being called and
 188                     // build the appropriate UFCS call expression with the
 189                     // callee-object as expr parameter.
 190
 191                     // rewrite f(u, v) into FnOnce::call_once(f, (u, v))
 192
 193                     let method = self.method_callee(expr, fun.span, None);
 194
 195                     let arg_tys = args.iter().map(|e| self.typeck_results().expr_ty_adjusted(e));
 196                     let tupled_args = Expr {
 197                         ty: self.tcx.mk_tup(arg_tys),
 198                         temp_lifetime,
 199                         span: expr.span,
 200                         kind: ExprKind::Tuple { fields: self.mirror_exprs(args) },
 201                     };
 202                     let tupled_args = self.thir.exprs.push(tupled_args);
 203
 204                     ExprKind::Call {
 205                         ty: method.ty,
 206                         fun: self.thir.exprs.push(method),
 207                         args: Box::new([self.mirror_expr(fun), tupled_args]),
 208                         from_hir_call: true,
 209                         fn_span: expr.span,
 210                     }
 211                 } else {
 212                     let adt_data =
 213                         if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = fun.kind {
 214                             // Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
 215                             expr_ty.ty_adt_def().and_then(|adt_def| match path.res {
 216                                 Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) => {
 217                                     Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id)))
 218                                 }
 219                                 Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
 220                                 _ => None,
 221                             })
 222                         } else {
 223                             None
 224                         };
 225                     if let Some((adt_def, index)) = adt_data {
 226                         let substs = self.typeck_results().node_substs(fun.hir_id);
 227                         let user_provided_types = self.typeck_results().user_provided_types();
 228                         let user_ty =
 229                             user_provided_types.get(fun.hir_id).copied().map(|mut u_ty| {
 230                                 if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
 231                                     *did = adt_def.did;
 232                                 }
 233                                 u_ty
 234                             });
 235                         debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
 236
 237                         let field_refs = args
 238                             .iter()
 239                             .enumerate()
 240                             .map(|(idx, e)| FieldExpr {
 241                                 name: Field::new(idx),
 242                                 expr: self.mirror_expr(e),
 243                             })
 244                             .collect();
 245                         ExprKind::Adt(Box::new(Adt {
 246                             adt_def,
 247                             substs,
 248                             variant_index: index,
 249                             fields: field_refs,
 250                             user_ty,
 251                             base: None,
 252                         }))
 253                     } else {
 254                         ExprKind::Call {
 255                             ty: self.typeck_results().node_type(fun.hir_id),
 256                             fun: self.mirror_expr(fun),
 257                             args: self.mirror_exprs(args),
 258                             from_hir_call: true,
 259                             fn_span: expr.span,
 260                         }
 261                     }
 262                 }
 263             }
 264
 265             hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, ref arg) => {
 266                 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: self.mirror_expr(arg) }
 267             }
 268
 269             hir::ExprKind::AddrOf(hir::BorrowKind::Raw, mutability, ref arg) => {
 270                 ExprKind::AddressOf { mutability, arg: self.mirror_expr(arg) }
 271             }
 272
 273             hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: self.mirror_block(blk) },
 274
 275             hir::ExprKind::Assign(ref lhs, ref rhs, _) => {
 276                 ExprKind::Assign { lhs: self.mirror_expr(lhs), rhs: self.mirror_expr(rhs) }
 277             }
 278
 279             hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
 280                 if self.typeck_results().is_method_call(expr) {
 281                     let lhs = self.mirror_expr(lhs);
 282                     let rhs = self.mirror_expr(rhs);
 283                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 284                 } else {
 285                     ExprKind::AssignOp {
 286                         op: bin_op(op.node),
 287                         lhs: self.mirror_expr(lhs),
 288                         rhs: self.mirror_expr(rhs),
 289                     }
 290                 }
 291             }
 292
 293             hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
 294                 literal: self.const_eval_literal(&lit.node, expr_ty, lit.span, false),
 295                 user_ty: None,
 296                 const_id: None,
 297             },
 298
 299             hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
 300                 if self.typeck_results().is_method_call(expr) {
 301                     let lhs = self.mirror_expr(lhs);
 302                     let rhs = self.mirror_expr(rhs);
 303                     self.overloaded_operator(expr, Box::new([lhs, rhs]))
 304                 } else {
 305                     // FIXME overflow
 306                     match op.node {
 307                         hir::BinOpKind::And => ExprKind::LogicalOp {
 308                             op: LogicalOp::And,
 309                             lhs: self.mirror_expr(lhs),
 310                             rhs: self.mirror_expr(rhs),
 311                         },
 312                         hir::BinOpKind::Or => ExprKind::LogicalOp {
 313                             op: LogicalOp::Or,
 314                             lhs: self.mirror_expr(lhs),
 315                             rhs: self.mirror_expr(rhs),
 316                         },
 317                         _ => {
 318                             let op = bin_op(op.node);
 319                             ExprKind::Binary {
 320                                 op,
 321                                 lhs: self.mirror_expr(lhs),
 322                                 rhs: self.mirror_expr(rhs),
 323                             }
 324                         }
 325                     }
 326                 }
 327             }
 328
 329             hir::ExprKind::Index(ref lhs, ref index) => {
 330                 if self.typeck_results().is_method_call(expr) {
 331                     let lhs = self.mirror_expr(lhs);
 332                     let index = self.mirror_expr(index);
 333                     self.overloaded_place(expr, expr_ty, None, Box::new([lhs, index]), expr.span)
 334                 } else {
 335                     ExprKind::Index { lhs: self.mirror_expr(lhs), index: self.mirror_expr(index) }
 336                 }
 337             }
 338
 339             hir::ExprKind::Unary(hir::UnOp::Deref, ref arg) => {
 340                 if self.typeck_results().is_method_call(expr) {
 341                     let arg = self.mirror_expr(arg);
 342                     self.overloaded_place(expr, expr_ty, None, Box::new([arg]), expr.span)
 343                 } else {
 344                     ExprKind::Deref { arg: self.mirror_expr(arg) }
 345                 }
 346             }
 347
 348             hir::ExprKind::Unary(hir::UnOp::Not, ref arg) => {
 349                 if self.typeck_results().is_method_call(expr) {
 350                     let arg = self.mirror_expr(arg);
 351                     self.overloaded_operator(expr, Box::new([arg]))
 352                 } else {
 353                     ExprKind::Unary { op: UnOp::Not, arg: self.mirror_expr(arg) }
 354                 }
 355             }
 356
 357             hir::ExprKind::Unary(hir::UnOp::Neg, ref arg) => {
 358                 if self.typeck_results().is_method_call(expr) {
 359                     let arg = self.mirror_expr(arg);
 360                     self.overloaded_operator(expr, Box::new([arg]))
 361                 } else if let hir::ExprKind::Lit(ref lit) = arg.kind {
 362                     ExprKind::Literal {
 363                         literal: self.const_eval_literal(&lit.node, expr_ty, lit.span, true),
 364                         user_ty: None,
 365                         const_id: None,
 366                     }
 367                 } else {
 368                     ExprKind::Unary { op: UnOp::Neg, arg: self.mirror_expr(arg) }
 369                 }
 370             }
 371
 372             hir::ExprKind::Struct(ref qpath, ref fields, ref base) => match expr_ty.kind() {
 373                 ty::Adt(adt, substs) => match adt.adt_kind() {
 374                     AdtKind::Struct | AdtKind::Union => {
 375                         let user_provided_types = self.typeck_results().user_provided_types();
 376                         let user_ty = user_provided_types.get(expr.hir_id).copied();
 377                         debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
 378                         ExprKind::Adt(Box::new(Adt {
 379                             adt_def: adt,
 380                             variant_index: VariantIdx::new(0),
 381                             substs,
 382                             user_ty,
 383                             fields: self.field_refs(fields),
 384                             base: base.as_ref().map(|base| FruInfo {
 385                                 base: self.mirror_expr(base),
 386                                 field_types: self.typeck_results().fru_field_types()[expr.hir_id]
 387                                     .iter()
 388                                     .copied()
 389                                     .collect(),
 390                             }),
 391                         }))
 392                     }
 393                     AdtKind::Enum => {
 394                         let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 395                         match res {
 396                             Res::Def(DefKind::Variant, variant_id) => {
 397                                 assert!(base.is_none());
 398
 399                                 let index = adt.variant_index_with_id(variant_id);
 400                                 let user_provided_types =
 401                                     self.typeck_results().user_provided_types();
 402                                 let user_ty = user_provided_types.get(expr.hir_id).copied();
 403                                 debug!("make_mirror_unadjusted: (variant) user_ty={:?}", user_ty);
 404                                 ExprKind::Adt(Box::new(Adt {
 405                                     adt_def: adt,
 406                                     variant_index: index,
 407                                     substs,
 408                                     user_ty,
 409                                     fields: self.field_refs(fields),
 410                                     base: None,
 411                                 }))
 412                             }
 413                             _ => {
 414                                 span_bug!(expr.span, "unexpected res: {:?}", res);
 415                             }
 416                         }
 417                     }
 418                 },
 419                 _ => {
 420                     span_bug!(expr.span, "unexpected type for struct literal: {:?}", expr_ty);
 421                 }
 422             },
 423
 424             hir::ExprKind::Closure(..) => {
 425                 let closure_ty = self.typeck_results().expr_ty(expr);
 426                 let (def_id, substs, movability) = match *closure_ty.kind() {
 427                     ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
 428                     ty::Generator(def_id, substs, movability) => {
 429                         (def_id, UpvarSubsts::Generator(substs), Some(movability))
 430                     }
 431                     _ => {
 432                         span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
 433                     }
 434                 };
 435
 436                 let upvars = self
 437                     .typeck_results
 438                     .closure_min_captures_flattened(def_id)
 439                     .zip(substs.upvar_tys())
 440                     .map(|(captured_place, ty)| {
 441                         let upvars = self.capture_upvar(expr, captured_place, ty);
 442                         self.thir.exprs.push(upvars)
 443                     })
 444                     .collect();
 445
 446                 // Convert the closure fake reads, if any, from hir `Place` to ExprRef
 447                 let fake_reads = match self.typeck_results.closure_fake_reads.get(&def_id) {
 448                     Some(fake_reads) => fake_reads
 449                         .iter()
 450                         .map(|(place, cause, hir_id)| {
 451                             let expr = self.convert_captured_hir_place(expr, place.clone());
 452                             (self.thir.exprs.push(expr), *cause, *hir_id)
 453                         })
 454                         .collect(),
 455                     None => Vec::new(),
 456                 };
 457
 458                 ExprKind::Closure { closure_id: def_id, substs, upvars, movability, fake_reads }
 459             }
 460
 461             hir::ExprKind::Path(ref qpath) => {
 462                 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 463                 self.convert_path_expr(expr, res)
 464             }
 465
 466             hir::ExprKind::InlineAsm(ref asm) => ExprKind::InlineAsm {
 467                 template: asm.template,
 468                 operands: asm
 469                     .operands
 470                     .iter()
 471                     .map(|(op, _op_sp)| {
 472                         match *op {
 473                             hir::InlineAsmOperand::In { reg, ref expr } => {
 474                                 InlineAsmOperand::In { reg, expr: self.mirror_expr(expr) }
 475                             }
 476                             hir::InlineAsmOperand::Out { reg, late, ref expr } => {
 477                                 InlineAsmOperand::Out {
 478                                     reg,
 479                                     late,
 480                                     expr: expr.as_ref().map(|expr| self.mirror_expr(expr)),
 481                                 }
 482                             }
 483                             hir::InlineAsmOperand::InOut { reg, late, ref expr } => {
 484                                 InlineAsmOperand::InOut { reg, late, expr: self.mirror_expr(expr) }
 485                             }
 486                             hir::InlineAsmOperand::SplitInOut {
 487                                 reg,
 488                                 late,
 489                                 ref in_expr,
 490                                 ref out_expr,
 491                             } => InlineAsmOperand::SplitInOut {
 492                                 reg,
 493                                 late,
 494                                 in_expr: self.mirror_expr(in_expr),
 495                                 out_expr: out_expr.as_ref().map(|expr| self.mirror_expr(expr)),
 496                             },
 497                             hir::InlineAsmOperand::Const { ref anon_const } => {
 498                                 let anon_const_def_id =
 499                                     self.tcx.hir().local_def_id(anon_const.hir_id);
 500                                 let value = ty::Const::from_anon_const(self.tcx, anon_const_def_id);
 501                                 let span = self.tcx.hir().span(anon_const.hir_id);
 502
 503                                 InlineAsmOperand::Const { value, span }
 504                             }
 505                             hir::InlineAsmOperand::Sym { ref expr } => {
 506                                 let hir::ExprKind::Path(ref qpath) = expr.kind else {
 507                                     span_bug!(
 508                                         expr.span,
 509                                         "asm `sym` operand should be a path, found {:?}",
 510                                         expr.kind
 511                                     );
 512                                 };
 513                                 let temp_lifetime =
 514                                     self.region_scope_tree.temporary_scope(expr.hir_id.local_id);
 515                                 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
 516                                 let ty;
 517                                 match res {
 518                                     Res::Def(DefKind::Fn, _) | Res::Def(DefKind::AssocFn, _) => {
 519                                         ty = self.typeck_results().node_type(expr.hir_id);
 520                                         let user_ty =
 521                                             self.user_substs_applied_to_res(expr.hir_id, res);
 522                                         InlineAsmOperand::SymFn {
 523                                             expr: self.thir.exprs.push(Expr {
 524                                                 ty,
 525                                                 temp_lifetime,
 526                                                 span: expr.span,
 527                                                 kind: ExprKind::Literal {
 528                                                     literal: ty::Const::zero_sized(self.tcx, ty),
 529                                                     user_ty,
 530                                                     const_id: None,
 531                                                 },
 532                                             }),
 533                                         }
 534                                     }
 535
 536                                     Res::Def(DefKind::Static, def_id) => {
 537                                         InlineAsmOperand::SymStatic { def_id }
 538                                     }
 539
 540                                     _ => {
 541                                         self.tcx.sess.span_err(
 542                                             expr.span,
 543                                             "asm `sym` operand must point to a fn or static",
 544                                         );
 545
 546                                         // Not a real fn, but we're not reaching codegen anyways...
 547                                         ty = self.tcx.ty_error();
 548                                         InlineAsmOperand::SymFn {
 549                                             expr: self.thir.exprs.push(Expr {
 550                                                 ty,
 551                                                 temp_lifetime,
 552                                                 span: expr.span,
 553                                                 kind: ExprKind::Literal {
 554                                                     literal: ty::Const::zero_sized(self.tcx, ty),
 555                                                     user_ty: None,
 556                                                     const_id: None,
 557                                                 },
 558                                             }),
 559                                         }
 560                                     }
 561                                 }
 562                             }
 563                         }
 564                     })
 565                     .collect(),
 566                 options: asm.options,
 567                 line_spans: asm.line_spans,
 568             },
 569
 570             hir::ExprKind::ConstBlock(ref anon_const) => {
 571                 let anon_const_def_id = self.tcx.hir().local_def_id(anon_const.hir_id);
 572                 let value = ty::Const::from_inline_const(self.tcx, anon_const_def_id);
 573
 574                 ExprKind::ConstBlock { value }
 575             }
 576             // Now comes the rote stuff:
 577             hir::ExprKind::Repeat(ref v, _) => {
 578                 let ty = self.typeck_results().expr_ty(expr);
 579                 let ty::Array(_, count) = ty.kind() else {
 580                     span_bug!(expr.span, "unexpected repeat expr ty: {:?}", ty);
 581                 };
 582
 583                 ExprKind::Repeat { value: self.mirror_expr(v), count: *count }
 584             }
 585             hir::ExprKind::Ret(ref v) => {
 586                 ExprKind::Return { value: v.as_ref().map(|v| self.mirror_expr(v)) }
 587             }
 588             hir::ExprKind::Break(dest, ref value) => match dest.target_id {
 589                 Ok(target_id) => ExprKind::Break {
 590                     label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node },
 591                     value: value.as_ref().map(|value| self.mirror_expr(value)),
 592                 },
 593                 Err(err) => bug!("invalid loop id for break: {}", err),
 594             },
 595             hir::ExprKind::Continue(dest) => match dest.target_id {
 596                 Ok(loop_id) => ExprKind::Continue {
 597                     label: region::Scope { id: loop_id.local_id, data: region::ScopeData::Node },
 598                 },
 599                 Err(err) => bug!("invalid loop id for continue: {}", err),
 600             },
 601             hir::ExprKind::Let(let_expr) => ExprKind::Let {
 602                 expr: self.mirror_expr(let_expr.init),
 603                 pat: self.pattern_from_hir(let_expr.pat),
 604             },
 605             hir::ExprKind::If(cond, then, else_opt) => ExprKind::If {
 606                 if_then_scope: region::Scope {
 607                     id: then.hir_id.local_id,
 608                     data: region::ScopeData::IfThen,
 609                 },
 610                 cond: self.mirror_expr(cond),
 611                 then: self.mirror_expr(then),
 612                 else_opt: else_opt.map(|el| self.mirror_expr(el)),
 613             },
 614             hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
 615                 scrutinee: self.mirror_expr(discr),
 616                 arms: arms.iter().map(|a| self.convert_arm(a)).collect(),
 617             },
 618             hir::ExprKind::Loop(ref body, ..) => {
 619                 let block_ty = self.typeck_results().node_type(body.hir_id);
 620                 let temp_lifetime = self.region_scope_tree.temporary_scope(body.hir_id.local_id);
 621                 let block = self.mirror_block(body);
 622                 let body = self.thir.exprs.push(Expr {
 623                     ty: block_ty,
 624                     temp_lifetime,
 625                     span: block.span,
 626                     kind: ExprKind::Block { body: block },
 627                 });
 628                 ExprKind::Loop { body }
 629             }
 630             hir::ExprKind::Field(ref source, ..) => ExprKind::Field {
 631                 lhs: self.mirror_expr(source),
 632                 name: Field::new(self.tcx.field_index(expr.hir_id, self.typeck_results)),
 633             },
 634             hir::ExprKind::Cast(ref source, ref cast_ty) => {
 635                 // Check for a user-given type annotation on this `cast`
 636                 let user_provided_types = self.typeck_results.user_provided_types();
 637                 let user_ty = user_provided_types.get(cast_ty.hir_id);
 638
 639                 debug!(
 640                     "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
 641                     expr, cast_ty.hir_id, user_ty,
 642                 );
 643
 644                 // Check to see if this cast is a "coercion cast", where the cast is actually done
 645                 // using a coercion (or is a no-op).
 646                 let cast = if self.typeck_results().is_coercion_cast(source.hir_id) {
 647                     // Convert the lexpr to a vexpr.
 648                     ExprKind::Use { source: self.mirror_expr(source) }
 649                 } else if self.typeck_results().expr_ty(source).is_region_ptr() {
 650                     // Special cased so that we can type check that the element
 651                     // type of the source matches the pointed to type of the
 652                     // destination.
 653                     ExprKind::Pointer {
 654                         source: self.mirror_expr(source),
 655                         cast: PointerCast::ArrayToPointer,
 656                     }
 657                 } else {
 658                     // check whether this is casting an enum variant discriminant
 659                     // to prevent cycles, we refer to the discriminant initializer
 660                     // which is always an integer and thus doesn't need to know the
 661                     // enum's layout (or its tag type) to compute it during const eval
 662                     // Example:
 663                     // enum Foo {
 664                     //     A,
 665                     //     B = A as isize + 4,
 666                     // }
 667                     // The correct solution would be to add symbolic computations to miri,
 668                     // so we wouldn't have to compute and store the actual value
 669                     let var = if let hir::ExprKind::Path(ref qpath) = source.kind {
 670                         let res = self.typeck_results().qpath_res(qpath, source.hir_id);
 671                         self.typeck_results().node_type(source.hir_id).ty_adt_def().and_then(
 672                             |adt_def| match res {
 673                                 Res::Def(
 674                                     DefKind::Ctor(CtorOf::Variant, CtorKind::Const),
 675                                     variant_ctor_id,
 676                                 ) => {
 677                                     let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
 678                                     let (d, o) = adt_def.discriminant_def_for_variant(idx);
 679                                     use rustc_middle::ty::util::IntTypeExt;
 680                                     let ty = adt_def.repr.discr_type();
 681                                     let ty = ty.to_ty(self.tcx());
 682                                     Some((d, o, ty))
 683                                 }
 684                                 _ => None,
 685                             },
 686                         )
 687                     } else {
 688                         None
 689                     };
 690
 691                     let source = if let Some((did, offset, var_ty)) = var {
 692                         let mk_const = |literal| Expr {
 693                             temp_lifetime,
 694                             ty: var_ty,
 695                             span: expr.span,
 696                             kind: ExprKind::Literal { literal, user_ty: None, const_id: None },
 697                         };
 698                         let offset = self.thir.exprs.push(mk_const(ty::Const::from_bits(
 699                             self.tcx,
 700                             offset as u128,
 701                             self.param_env.and(var_ty),
 702                         )));
 703                         match did {
 704                             Some(did) => {
 705                                 // in case we are offsetting from a computed discriminant
 706                                 // and not the beginning of discriminants (which is always `0`)
 707                                 let substs = InternalSubsts::identity_for_item(self.tcx(), did);
 708                                 let lhs = ty::ConstS {
 709                                     val: ty::ConstKind::Unevaluated(ty::Unevaluated::new(
 710                                         ty::WithOptConstParam::unknown(did),
 711                                         substs,
 712                                     )),
 713                                     ty: var_ty,
 714                                 };
 715                                 let lhs = self.thir.exprs.push(mk_const(self.tcx().mk_const(lhs)));
 716                                 let bin =
 717                                     ExprKind::Binary { op: BinOp::Add, lhs: lhs, rhs: offset };
 718                                 self.thir.exprs.push(Expr {
 719                                     temp_lifetime,
 720                                     ty: var_ty,
 721                                     span: expr.span,
 722                                     kind: bin,
 723                                 })
 724                             }
 725                             None => offset,
 726                         }
 727                     } else {
 728                         self.mirror_expr(source)
 729                     };
 730
 731                     ExprKind::Cast { source: source }
 732                 };
 733
 734                 if let Some(user_ty) = user_ty {
 735                     // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
 736                     //       inefficient, revisit this when performance becomes an issue.
 737                     let cast_expr = self.thir.exprs.push(Expr {
 738                         temp_lifetime,
 739                         ty: expr_ty,
 740                         span: expr.span,
 741                         kind: cast,
 742                     });
 743                     debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
 744
 745                     ExprKind::ValueTypeAscription { source: cast_expr, user_ty: Some(*user_ty) }
 746                 } else {
 747                     cast
 748                 }
 749             }
 750             hir::ExprKind::Type(ref source, ref ty) => {
 751                 let user_provided_types = self.typeck_results.user_provided_types();
 752                 let user_ty = user_provided_types.get(ty.hir_id).copied();
 753                 debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
 754                 let mirrored = self.mirror_expr(source);
 755                 if source.is_syntactic_place_expr() {
 756                     ExprKind::PlaceTypeAscription { source: mirrored, user_ty }
 757                 } else {
 758                     ExprKind::ValueTypeAscription { source: mirrored, user_ty }
 759                 }
 760             }
 761             hir::ExprKind::DropTemps(ref source) => {
 762                 ExprKind::Use { source: self.mirror_expr(source) }
 763             }
 764             hir::ExprKind::Box(ref value) => ExprKind::Box { value: self.mirror_expr(value) },
 765             hir::ExprKind::Array(ref fields) => {
 766                 ExprKind::Array { fields: self.mirror_exprs(fields) }
 767             }
 768             hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: self.mirror_exprs(fields) },
 769
 770             hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: self.mirror_expr(v) },
 771             hir::ExprKind::Err => unreachable!(),
 772         };
 773
 774         Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
 775     }
 776
 777     fn user_substs_applied_to_res(
 778         &mut self,
 779         hir_id: hir::HirId,
 780         res: Res,
 781     ) -> Option<ty::CanonicalUserType<'tcx>> {
 782         debug!("user_substs_applied_to_res: res={:?}", res);
 783         let user_provided_type = match res {
 784             // A reference to something callable -- e.g., a fn, method, or
 785             // a tuple-struct or tuple-variant. This has the type of a
 786             // `Fn` but with the user-given substitutions.
 787             Res::Def(DefKind::Fn, _)
 788             | Res::Def(DefKind::AssocFn, _)
 789             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 790             | Res::Def(DefKind::Const, _)
 791             | Res::Def(DefKind::AssocConst, _) => {
 792                 self.typeck_results().user_provided_types().get(hir_id).copied()
 793             }
 794
 795             // A unit struct/variant which is used as a value (e.g.,
 796             // `None`). This has the type of the enum/struct that defines
 797             // this variant -- but with the substitutions given by the
 798             // user.
 799             Res::Def(DefKind::Ctor(_, CtorKind::Const), _) => {
 800                 self.user_substs_applied_to_ty_of_hir_id(hir_id)
 801             }
 802
 803             // `Self` is used in expression as a tuple struct constructor or a unit struct constructor
 804             Res::SelfCtor(_) => self.user_substs_applied_to_ty_of_hir_id(hir_id),
 805
 806             _ => bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id),
 807         };
 808         debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
 809         user_provided_type
 810     }
 811
 812     fn method_callee(
 813         &mut self,
 814         expr: &hir::Expr<'_>,
 815         span: Span,
 816         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 817     ) -> Expr<'tcx> {
 818         let temp_lifetime = self.region_scope_tree.temporary_scope(expr.hir_id.local_id);
 819         let (def_id, substs, user_ty) = match overloaded_callee {
 820             Some((def_id, substs)) => (def_id, substs, None),
 821             None => {
 822                 let (kind, def_id) =
 823                     self.typeck_results().type_dependent_def(expr.hir_id).unwrap_or_else(|| {
 824                         span_bug!(expr.span, "no type-dependent def for method callee")
 825                     });
 826                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, Res::Def(kind, def_id));
 827                 debug!("method_callee: user_ty={:?}", user_ty);
 828                 (def_id, self.typeck_results().node_substs(expr.hir_id), user_ty)
 829             }
 830         };
 831         let ty = self.tcx().mk_fn_def(def_id, substs);
 832         Expr {
 833             temp_lifetime,
 834             ty,
 835             span,
 836             kind: ExprKind::Literal {
 837                 literal: ty::Const::zero_sized(self.tcx(), ty),
 838                 user_ty,
 839                 const_id: None,
 840             },
 841         }
 842     }
 843
 844     fn convert_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) -> ArmId {
 845         let arm = Arm {
 846             pattern: self.pattern_from_hir(&arm.pat),
 847             guard: arm.guard.as_ref().map(|g| match g {
 848                 hir::Guard::If(ref e) => Guard::If(self.mirror_expr(e)),
 849                 hir::Guard::IfLet(ref pat, ref e) => {
 850                     Guard::IfLet(self.pattern_from_hir(pat), self.mirror_expr(e))
 851                 }
 852             }),
 853             body: self.mirror_expr(arm.body),
 854             lint_level: LintLevel::Explicit(arm.hir_id),
 855             scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
 856             span: arm.span,
 857         };
 858         self.thir.arms.push(arm)
 859     }
 860
 861     fn convert_path_expr(&mut self, expr: &'tcx hir::Expr<'tcx>, res: Res) -> ExprKind<'tcx> {
 862         let substs = self.typeck_results().node_substs(expr.hir_id);
 863         match res {
 864             // A regular function, constructor function or a constant.
 865             Res::Def(DefKind::Fn, _)
 866             | Res::Def(DefKind::AssocFn, _)
 867             | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
 868             | Res::SelfCtor(..) => {
 869                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 870                 debug!("convert_path_expr: user_ty={:?}", user_ty);
 871                 ExprKind::Literal {
 872                     literal: ty::Const::zero_sized(
 873                         self.tcx,
 874                         self.typeck_results().node_type(expr.hir_id),
 875                     ),
 876                     user_ty,
 877                     const_id: None,
 878                 }
 879             }
 880
 881             Res::Def(DefKind::ConstParam, def_id) => {
 882                 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
 883                 let item_id = self.tcx.hir().get_parent_node(hir_id);
 884                 let item_def_id = self.tcx.hir().local_def_id(item_id);
 885                 let generics = self.tcx.generics_of(item_def_id);
 886                 let index = generics.param_def_id_to_index[&def_id];
 887                 let name = self.tcx.hir().name(hir_id);
 888                 let val = ty::ConstKind::Param(ty::ParamConst::new(index, name));
 889                 ExprKind::Literal {
 890                     literal: self.tcx.mk_const(ty::ConstS {
 891                         val,
 892                         ty: self.typeck_results().node_type(expr.hir_id),
 893                     }),
 894                     user_ty: None,
 895                     const_id: Some(def_id),
 896                 }
 897             }
 898
 899             Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => {
 900                 let user_ty = self.user_substs_applied_to_res(expr.hir_id, res);
 901                 debug!("convert_path_expr: (const) user_ty={:?}", user_ty);
 902                 ExprKind::Literal {
 903                     literal: self.tcx.mk_const(ty::ConstS {
 904                         val: ty::ConstKind::Unevaluated(ty::Unevaluated::new(
 905                             ty::WithOptConstParam::unknown(def_id),
 906                             substs,
 907                         )),
 908                         ty: self.typeck_results().node_type(expr.hir_id),
 909                     }),
 910                     user_ty,
 911                     const_id: Some(def_id),
 912                 }
 913             }
 914
 915             Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
 916                 let user_provided_types = self.typeck_results.user_provided_types();
 917                 let user_provided_type = user_provided_types.get(expr.hir_id).copied();
 918                 debug!("convert_path_expr: user_provided_type={:?}", user_provided_type);
 919                 let ty = self.typeck_results().node_type(expr.hir_id);
 920                 match ty.kind() {
 921                     // A unit struct/variant which is used as a value.
 922                     // We return a completely different ExprKind here to account for this special case.
 923                     ty::Adt(adt_def, substs) => ExprKind::Adt(Box::new(Adt {
 924                         adt_def,
 925                         variant_index: adt_def.variant_index_with_ctor_id(def_id),
 926                         substs,
 927                         user_ty: user_provided_type,
 928                         fields: Box::new([]),
 929                         base: None,
 930                     })),
 931                     _ => bug!("unexpected ty: {:?}", ty),
 932                 }
 933             }
 934
 935             // We encode uses of statics as a `*&STATIC` where the `&STATIC` part is
 936             // a constant reference (or constant raw pointer for `static mut`) in MIR
 937             Res::Def(DefKind::Static, id) => {
 938                 let ty = self.tcx.static_ptr_ty(id);
 939                 let temp_lifetime = self.region_scope_tree.temporary_scope(expr.hir_id.local_id);
 940                 let kind = if self.tcx.is_thread_local_static(id) {
 941                     ExprKind::ThreadLocalRef(id)
 942                 } else {
 943                     let alloc_id = self.tcx.create_static_alloc(id);
 944                     ExprKind::StaticRef { alloc_id, ty, def_id: id }
 945                 };
 946                 ExprKind::Deref {
 947                     arg: self.thir.exprs.push(Expr { ty, temp_lifetime, span: expr.span, kind }),
 948                 }
 949             }
 950
 951             Res::Local(var_hir_id) => self.convert_var(var_hir_id),
 952
 953             _ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
 954         }
 955     }
 956
 957     fn convert_var(&mut self, var_hir_id: hir::HirId) -> ExprKind<'tcx> {
 958         // We want upvars here not captures.
 959         // Captures will be handled in MIR.
 960         let is_upvar = self
 961             .tcx
 962             .upvars_mentioned(self.body_owner)
 963             .map_or(false, |upvars| upvars.contains_key(&var_hir_id));
 964
 965         debug!(
 966             "convert_var({:?}): is_upvar={}, body_owner={:?}",
 967             var_hir_id, is_upvar, self.body_owner
 968         );
 969
 970         if is_upvar {
 971             ExprKind::UpvarRef { closure_def_id: self.body_owner, var_hir_id }
 972         } else {
 973             ExprKind::VarRef { id: var_hir_id }
 974         }
 975     }
 976
 977     fn overloaded_operator(
 978         &mut self,
 979         expr: &'tcx hir::Expr<'tcx>,
 980         args: Box<[ExprId]>,
 981     ) -> ExprKind<'tcx> {
 982         let fun = self.method_callee(expr, expr.span, None);
 983         let fun = self.thir.exprs.push(fun);
 984         ExprKind::Call {
 985             ty: self.thir[fun].ty,
 986             fun,
 987             args,
 988             from_hir_call: false,
 989             fn_span: expr.span,
 990         }
 991     }
 992
 993     fn overloaded_place(
 994         &mut self,
 995         expr: &'tcx hir::Expr<'tcx>,
 996         place_ty: Ty<'tcx>,
 997         overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
 998         args: Box<[ExprId]>,
 999         span: Span,
1000     ) -> ExprKind<'tcx> {
1001         // For an overloaded *x or x[y] expression of type T, the method
1002         // call returns an &T and we must add the deref so that the types
1003         // line up (this is because `*x` and `x[y]` represent places):
1004
1005         // Reconstruct the output assuming it's a reference with the
1006         // same region and mutability as the receiver. This holds for
1007         // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
1008         let ty::Ref(region, _, mutbl) = *self.thir[args[0]].ty.kind() else {
1009             span_bug!(span, "overloaded_place: receiver is not a reference");
1010         };
1011         let ref_ty = self.tcx.mk_ref(region, ty::TypeAndMut { ty: place_ty, mutbl });
1012
1013         // construct the complete expression `foo()` for the overloaded call,
1014         // which will yield the &T type
1015         let temp_lifetime = self.region_scope_tree.temporary_scope(expr.hir_id.local_id);
1016         let fun = self.method_callee(expr, span, overloaded_callee);
1017         let fun = self.thir.exprs.push(fun);
1018         let fun_ty = self.thir[fun].ty;
1019         let ref_expr = self.thir.exprs.push(Expr {
1020             temp_lifetime,
1021             ty: ref_ty,
1022             span,
1023             kind: ExprKind::Call { ty: fun_ty, fun, args, from_hir_call: false, fn_span: span },
1024         });
1025
1026         // construct and return a deref wrapper `*foo()`
1027         ExprKind::Deref { arg: ref_expr }
1028     }
1029
1030     fn convert_captured_hir_place(
1031         &mut self,
1032         closure_expr: &'tcx hir::Expr<'tcx>,
1033         place: HirPlace<'tcx>,
1034     ) -> Expr<'tcx> {
1035         let temp_lifetime = self.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1036         let var_ty = place.base_ty;
1037
1038         // The result of capture analysis in `rustc_typeck/check/upvar.rs`represents a captured path
1039         // as it's seen for use within the closure and not at the time of closure creation.
1040         //
1041         // That is we see expect to see it start from a captured upvar and not something that is local
1042         // to the closure's parent.
1043         let var_hir_id = match place.base {
1044             HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id,
1045             base => bug!("Expected an upvar, found {:?}", base),
1046         };
1047
1048         let mut captured_place_expr = Expr {
1049             temp_lifetime,
1050             ty: var_ty,
1051             span: closure_expr.span,
1052             kind: self.convert_var(var_hir_id),
1053         };
1054
1055         for proj in place.projections.iter() {
1056             let kind = match proj.kind {
1057                 HirProjectionKind::Deref => {
1058                     ExprKind::Deref { arg: self.thir.exprs.push(captured_place_expr) }
1059                 }
1060                 HirProjectionKind::Field(field, ..) => {
1061                     // Variant index will always be 0, because for multi-variant
1062                     // enums, we capture the enum entirely.
1063                     ExprKind::Field {
1064                         lhs: self.thir.exprs.push(captured_place_expr),
1065                         name: Field::new(field as usize),
1066                     }
1067                 }
1068                 HirProjectionKind::Index | HirProjectionKind::Subslice => {
1069                     // We don't capture these projections, so we can ignore them here
1070                     continue;
1071                 }
1072             };
1073
1074             captured_place_expr =
1075                 Expr { temp_lifetime, ty: proj.ty, span: closure_expr.span, kind };
1076         }
1077
1078         captured_place_expr
1079     }
1080
1081     fn capture_upvar(
1082         &mut self,
1083         closure_expr: &'tcx hir::Expr<'tcx>,
1084         captured_place: &'tcx ty::CapturedPlace<'tcx>,
1085         upvar_ty: Ty<'tcx>,
1086     ) -> Expr<'tcx> {
1087         let upvar_capture = captured_place.info.capture_kind;
1088         let captured_place_expr =
1089             self.convert_captured_hir_place(closure_expr, captured_place.place.clone());
1090         let temp_lifetime = self.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
1091
1092         match upvar_capture {
1093             ty::UpvarCapture::ByValue => captured_place_expr,
1094             ty::UpvarCapture::ByRef(upvar_borrow) => {
1095                 let borrow_kind = match upvar_borrow {
1096                     ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
1097                     ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
1098                     ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false },
1099                 };
1100                 Expr {
1101                     temp_lifetime,
1102                     ty: upvar_ty,
1103                     span: closure_expr.span,
1104                     kind: ExprKind::Borrow {
1105                         borrow_kind,
1106                         arg: self.thir.exprs.push(captured_place_expr),
1107                     },
1108                 }
1109             }
1110         }
1111     }
1112
1113     /// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExpr.
1114     fn field_refs(&mut self, fields: &'tcx [hir::ExprField<'tcx>]) -> Box<[FieldExpr]> {
1115         fields
1116             .iter()
1117             .map(|field| FieldExpr {
1118                 name: Field::new(self.tcx.field_index(field.hir_id, self.typeck_results)),
1119                 expr: self.mirror_expr(field.expr),
1120             })
1121             .collect()
1122     }
1123 }
1124
1125 trait ToBorrowKind {
1126     fn to_borrow_kind(&self) -> BorrowKind;
1127 }
1128
1129 impl ToBorrowKind for AutoBorrowMutability {
1130     fn to_borrow_kind(&self) -> BorrowKind {
1131         use rustc_middle::ty::adjustment::AllowTwoPhase;
1132         match *self {
1133             AutoBorrowMutability::Mut { allow_two_phase_borrow } => BorrowKind::Mut {
1134                 allow_two_phase_borrow: match allow_two_phase_borrow {
1135                     AllowTwoPhase::Yes => true,
1136                     AllowTwoPhase::No => false,
1137                 },
1138             },
1139             AutoBorrowMutability::Not => BorrowKind::Shared,
1140         }
1141     }
1142 }
1143
1144 impl ToBorrowKind for hir::Mutability {
1145     fn to_borrow_kind(&self) -> BorrowKind {
1146         match *self {
1147             hir::Mutability::Mut => BorrowKind::Mut { allow_two_phase_borrow: false },
1148             hir::Mutability::Not => BorrowKind::Shared,
1149         }
1150     }
1151 }
1152
1153 fn bin_op(op: hir::BinOpKind) -> BinOp {
1154     match op {
1155         hir::BinOpKind::Add => BinOp::Add,
1156         hir::BinOpKind::Sub => BinOp::Sub,
1157         hir::BinOpKind::Mul => BinOp::Mul,
1158         hir::BinOpKind::Div => BinOp::Div,
1159         hir::BinOpKind::Rem => BinOp::Rem,
1160         hir::BinOpKind::BitXor => BinOp::BitXor,
1161         hir::BinOpKind::BitAnd => BinOp::BitAnd,
1162         hir::BinOpKind::BitOr => BinOp::BitOr,
1163         hir::BinOpKind::Shl => BinOp::Shl,
1164         hir::BinOpKind::Shr => BinOp::Shr,
1165         hir::BinOpKind::Eq => BinOp::Eq,
1166         hir::BinOpKind::Lt => BinOp::Lt,
1167         hir::BinOpKind::Le => BinOp::Le,
1168         hir::BinOpKind::Ne => BinOp::Ne,
1169         hir::BinOpKind::Ge => BinOp::Ge,
1170         hir::BinOpKind::Gt => BinOp::Gt,
1171         _ => bug!("no equivalent for ast binop {:?}", op),
1172     }
1173 }