1 pub(crate) use crate::build::expr::as_constant::lit_to_mir_constant;
2 use crate::build::expr::as_place::PlaceBuilder;
3 use crate::build::scope::DropKind;
4 use rustc_apfloat::ieee::{Double, Single};
5 use rustc_apfloat::Float;
6 use rustc_data_structures::fx::FxHashMap;
7 use rustc_data_structures::sorted_map::SortedIndexMultiMap;
8 use rustc_errors::ErrorGuaranteed;
10 use rustc_hir::def::DefKind;
11 use rustc_hir::def_id::{DefId, LocalDefId};
12 use rustc_hir::{GeneratorKind, Node};
13 use rustc_index::vec::{Idx, IndexVec};
14 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
15 use rustc_middle::hir::place::PlaceBase as HirPlaceBase;
16 use rustc_middle::middle::region;
17 use rustc_middle::mir::interpret::ConstValue;
18 use rustc_middle::mir::interpret::Scalar;
19 use rustc_middle::mir::*;
20 use rustc_middle::thir::{
21 self, BindingMode, Expr, ExprId, LintLevel, LocalVarId, Param, ParamId, PatKind, Thir,
23 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable, TypeckResults};
24 use rustc_span::symbol::sym;
26 use rustc_span::Symbol;
27 use rustc_target::spec::abi::Abi;
31 pub(crate) fn mir_built<'tcx>(
33 def: ty::WithOptConstParam<LocalDefId>,
34 ) -> &'tcx rustc_data_structures::steal::Steal<Body<'tcx>> {
35 if let Some(def) = def.try_upgrade(tcx) {
36 return tcx.mir_built(def);
39 let mut body = mir_build(tcx, def);
40 if def.const_param_did.is_some() {
41 assert!(matches!(body.source.instance, ty::InstanceDef::Item(_)));
42 body.source = MirSource::from_instance(ty::InstanceDef::Item(def.to_global()));
45 tcx.alloc_steal_mir(body)
48 /// Construct the MIR for a given `DefId`.
49 fn mir_build(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> Body<'_> {
50 let body_owner_kind = tcx.hir().body_owner_kind(def.did);
52 // Ensure unsafeck and abstract const building is ran before we steal the THIR.
53 // We can't use `ensure()` for `thir_abstract_const` as it doesn't compute the query
54 // if inputs are green. This can cause ICEs when calling `thir_abstract_const` after
55 // THIR has been stolen if we haven't computed this query yet.
57 ty::WithOptConstParam { did, const_param_did: Some(const_param_did) } => {
58 tcx.ensure().thir_check_unsafety_for_const_arg((did, const_param_did));
59 drop(tcx.thir_abstract_const_of_const_arg((did, const_param_did)));
61 ty::WithOptConstParam { did, const_param_did: None } => {
62 tcx.ensure().thir_check_unsafety(did);
63 drop(tcx.thir_abstract_const(did));
67 let body = match tcx.thir_body(def) {
68 Err(error_reported) => construct_error(tcx, def.did, body_owner_kind, error_reported),
70 // We ran all queries that depended on THIR at the beginning
71 // of `mir_build`, so now we can steal it
72 let thir = thir.steal();
74 if body_owner_kind.is_fn_or_closure() {
75 construct_fn(tcx, def, &thir, expr)
77 construct_const(tcx, def, &thir, expr)
82 lints::check(tcx, &body);
84 // The borrow checker will replace all the regions here with its own
85 // inference variables. There's no point having non-erased regions here.
86 // The exception is `body.user_type_annotations`, which is used unmodified
87 // by borrow checking.
89 !(body.local_decls.has_free_regions()
90 || body.basic_blocks.has_free_regions()
91 || body.var_debug_info.has_free_regions()
92 || body.yield_ty().has_free_regions()),
93 "Unexpected free regions in MIR: {:?}",
100 ///////////////////////////////////////////////////////////////////////////
101 // BuildMir -- walks a crate, looking for fn items and methods to build MIR from
103 #[derive(Debug, PartialEq, Eq)]
105 /// Evaluation is currently within a statement.
107 /// Examples include:
109 /// 2. `let _ = EXPR;`
110 /// 3. `let x = EXPR;`
112 /// If true, then statement discards result from evaluating
113 /// the expression (such as examples 1 and 2 above).
114 ignores_expr_result: bool,
117 /// Evaluation is currently within the tail expression of a block.
119 /// Example: `{ STMT_1; STMT_2; EXPR }`
121 /// If true, then the surrounding context of the block ignores
122 /// the result of evaluating the block's tail expression.
124 /// Example: `let _ = { STMT_1; EXPR };`
125 tail_result_is_ignored: bool,
127 /// `Span` of the tail expression.
131 /// Generic mark meaning that the block occurred as a subexpression
132 /// where the result might be used.
134 /// Examples: `foo(EXPR)`, `match EXPR { ... }`
139 fn is_tail_expr(&self) -> bool {
141 BlockFrame::TailExpr { .. } => true,
143 BlockFrame::Statement { .. } | BlockFrame::SubExpr => false,
146 fn is_statement(&self) -> bool {
148 BlockFrame::Statement { .. } => true,
150 BlockFrame::TailExpr { .. } | BlockFrame::SubExpr => false,
156 struct BlockContext(Vec<BlockFrame>);
158 struct Builder<'a, 'tcx> {
160 infcx: InferCtxt<'tcx>,
161 typeck_results: &'tcx TypeckResults<'tcx>,
162 region_scope_tree: &'tcx region::ScopeTree,
163 param_env: ty::ParamEnv<'tcx>,
165 thir: &'a Thir<'tcx>,
170 parent_module: DefId,
171 check_overflow: bool,
174 generator_kind: Option<GeneratorKind>,
176 /// The current set of scopes, updated as we traverse;
177 /// see the `scope` module for more details.
178 scopes: scope::Scopes<'tcx>,
180 /// The block-context: each time we build the code within an thir::Block,
181 /// we push a frame here tracking whether we are building a statement or
182 /// if we are pushing the tail expression of the block. This is used to
183 /// embed information in generated temps about whether they were created
184 /// for a block tail expression or not.
186 /// It would be great if we could fold this into `self.scopes`
187 /// somehow, but right now I think that is very tightly tied to
188 /// the code generation in ways that we cannot (or should not)
189 /// start just throwing new entries onto that vector in order to
190 /// distinguish the context of EXPR1 from the context of EXPR2 in
191 /// `{ STMTS; EXPR1 } + EXPR2`.
192 block_context: BlockContext,
194 /// The current unsafe block in scope
195 in_scope_unsafe: Safety,
197 /// The vector of all scopes that we have created thus far;
198 /// we track this for debuginfo later.
199 source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
200 source_scope: SourceScope,
202 /// The guard-context: each time we build the guard expression for
203 /// a match arm, we push onto this stack, and then pop when we
204 /// finish building it.
205 guard_context: Vec<GuardFrame>,
207 /// Maps `HirId`s of variable bindings to the `Local`s created for them.
208 /// (A match binding can have two locals; the 2nd is for the arm's guard.)
209 var_indices: FxHashMap<LocalVarId, LocalsForNode>,
210 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
211 canonical_user_type_annotations: ty::CanonicalUserTypeAnnotations<'tcx>,
212 upvars: CaptureMap<'tcx>,
213 unit_temp: Option<Place<'tcx>>,
215 var_debug_info: Vec<VarDebugInfo<'tcx>>,
218 type CaptureMap<'tcx> = SortedIndexMultiMap<usize, hir::HirId, Capture<'tcx>>;
221 struct Capture<'tcx> {
222 captured_place: &'tcx ty::CapturedPlace<'tcx>,
223 use_place: Place<'tcx>,
224 mutability: Mutability,
227 impl<'a, 'tcx> Builder<'a, 'tcx> {
228 fn is_bound_var_in_guard(&self, id: LocalVarId) -> bool {
229 self.guard_context.iter().any(|frame| frame.locals.iter().any(|local| local.id == id))
232 fn var_local_id(&self, id: LocalVarId, for_guard: ForGuard) -> Local {
233 self.var_indices[&id].local_id(for_guard)
241 fn push(&mut self, bf: BlockFrame) {
244 fn pop(&mut self) -> Option<BlockFrame> {
248 /// Traverses the frames on the `BlockContext`, searching for either
249 /// the first block-tail expression frame with no intervening
252 /// Notably, this skips over `SubExpr` frames; this method is
253 /// meant to be used in the context of understanding the
254 /// relationship of a temp (created within some complicated
255 /// expression) with its containing expression, and whether the
256 /// value of that *containing expression* (not the temp!) is
258 fn currently_in_block_tail(&self) -> Option<BlockTailInfo> {
259 for bf in self.0.iter().rev() {
261 BlockFrame::SubExpr => continue,
262 BlockFrame::Statement { .. } => break,
263 &BlockFrame::TailExpr { tail_result_is_ignored, span } => {
264 return Some(BlockTailInfo { tail_result_is_ignored, span });
272 /// Looks at the topmost frame on the BlockContext and reports
273 /// whether its one that would discard a block tail result.
275 /// Unlike `currently_within_ignored_tail_expression`, this does
276 /// *not* skip over `SubExpr` frames: here, we want to know
277 /// whether the block result itself is discarded.
278 fn currently_ignores_tail_results(&self) -> bool {
279 match self.0.last() {
280 // no context: conservatively assume result is read
283 // sub-expression: block result feeds into some computation
284 Some(BlockFrame::SubExpr) => false,
286 // otherwise: use accumulated is_ignored state.
288 BlockFrame::TailExpr { tail_result_is_ignored: ignored, .. }
289 | BlockFrame::Statement { ignores_expr_result: ignored },
297 /// In the usual case, a `HirId` for an identifier maps to at most
298 /// one `Local` declaration.
301 /// The exceptional case is identifiers in a match arm's pattern
302 /// that are referenced in a guard of that match arm. For these,
303 /// we have `2` Locals.
305 /// * `for_arm_body` is the Local used in the arm body (which is
306 /// just like the `One` case above),
308 /// * `ref_for_guard` is the Local used in the arm's guard (which
309 /// is a reference to a temp that is an alias of
311 ForGuard { ref_for_guard: Local, for_arm_body: Local },
315 struct GuardFrameLocal {
319 impl GuardFrameLocal {
320 fn new(id: LocalVarId, _binding_mode: BindingMode) -> Self {
321 GuardFrameLocal { id }
327 /// These are the id's of names that are bound by patterns of the
328 /// arm of *this* guard.
330 /// (Frames higher up the stack will have the id's bound in arms
331 /// further out, such as in a case like:
334 /// P1(id1) if (... (match E2 { P2(id2) if ... => B2 })) => B1,
337 /// here, when building for FIXME.
338 locals: Vec<GuardFrameLocal>,
341 /// `ForGuard` indicates whether we are talking about:
342 /// 1. The variable for use outside of guard expressions, or
343 /// 2. The temp that holds reference to (1.), which is actually what the
344 /// guard expressions see.
345 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
352 fn local_id(&self, for_guard: ForGuard) -> Local {
353 match (self, for_guard) {
354 (&LocalsForNode::One(local_id), ForGuard::OutsideGuard)
356 &LocalsForNode::ForGuard { ref_for_guard: local_id, .. },
357 ForGuard::RefWithinGuard,
359 | (&LocalsForNode::ForGuard { for_arm_body: local_id, .. }, ForGuard::OutsideGuard) => {
363 (&LocalsForNode::One(_), ForGuard::RefWithinGuard) => {
364 bug!("anything with one local should never be within a guard.")
371 basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
374 rustc_index::newtype_index! {
375 struct ScopeId { .. }
379 enum NeedsTemporary {
380 /// Use this variant when whatever you are converting with `as_operand`
381 /// is the last thing you are converting. This means that if we introduced
382 /// an intermediate temporary, we'd only read it immediately after, so we can
385 /// For all cases where you aren't sure or that are too expensive to compute
386 /// for now. It is always safe to fall back to this.
390 ///////////////////////////////////////////////////////////////////////////
391 /// The `BlockAnd` "monad" packages up the new basic block along with a
392 /// produced value (sometimes just unit, of course). The `unpack!`
393 /// macro (and methods below) makes working with `BlockAnd` much more
396 #[must_use = "if you don't use one of these results, you're leaving a dangling edge"]
397 struct BlockAnd<T>(BasicBlock, T);
399 trait BlockAndExtension {
400 fn and<T>(self, v: T) -> BlockAnd<T>;
401 fn unit(self) -> BlockAnd<()>;
404 impl BlockAndExtension for BasicBlock {
405 fn and<T>(self, v: T) -> BlockAnd<T> {
409 fn unit(self) -> BlockAnd<()> {
414 /// Update a block pointer and return the value.
415 /// Use it like `let x = unpack!(block = self.foo(block, foo))`.
416 macro_rules! unpack {
417 ($x:ident = $c:expr) => {{
418 let BlockAnd(b, v) = $c;
424 let BlockAnd(b, ()) = $c;
429 ///////////////////////////////////////////////////////////////////////////
430 /// the main entry point for building MIR for a function
432 fn construct_fn<'tcx>(
434 fn_def: ty::WithOptConstParam<LocalDefId>,
438 let span = tcx.def_span(fn_def.did);
439 let fn_id = tcx.hir().local_def_id_to_hir_id(fn_def.did);
440 let generator_kind = tcx.generator_kind(fn_def.did);
442 // Figure out what primary body this item has.
443 let body_id = tcx.hir().body_owned_by(fn_def.did);
444 let span_with_body = tcx.hir().span_with_body(fn_id);
445 let return_ty_span = tcx
447 .fn_decl_by_hir_id(fn_id)
448 .unwrap_or_else(|| span_bug!(span, "can't build MIR for {:?}", fn_def.did))
452 // fetch the fully liberated fn signature (that is, all bound
453 // types/lifetimes replaced)
454 let typeck_results = tcx.typeck_opt_const_arg(fn_def);
455 let fn_sig = typeck_results.liberated_fn_sigs()[fn_id];
457 let safety = match fn_sig.unsafety {
458 hir::Unsafety::Normal => Safety::Safe,
459 hir::Unsafety::Unsafe => Safety::FnUnsafe,
462 let mut abi = fn_sig.abi;
463 if let DefKind::Closure = tcx.def_kind(fn_def.did) {
464 // HACK(eddyb) Avoid having RustCall on closures,
465 // as it adds unnecessary (and wrong) auto-tupling.
469 let arguments = &thir.params;
471 let (yield_ty, return_ty) = if generator_kind.is_some() {
472 let gen_ty = arguments[thir::UPVAR_ENV_PARAM].ty;
473 let gen_sig = match gen_ty.kind() {
474 ty::Generator(_, gen_substs, ..) => gen_substs.as_generator().sig(),
476 span_bug!(span, "generator w/o generator type: {:?}", gen_ty)
479 (Some(gen_sig.yield_ty), gen_sig.return_ty)
481 (None, fn_sig.output())
484 if let Some(custom_mir_attr) =
485 tcx.hir().attrs(fn_id).iter().find(|attr| attr.name_or_empty() == sym::custom_mir)
487 return custom::build_custom_mir(
489 fn_def.did.to_def_id(),
500 let infcx = tcx.infer_ctxt().build();
501 let mut builder = Builder::new(
514 let call_site_scope =
515 region::Scope { id: body_id.hir_id.local_id, data: region::ScopeData::CallSite };
517 region::Scope { id: body_id.hir_id.local_id, data: region::ScopeData::Arguments };
518 let source_info = builder.source_info(span);
519 let call_site_s = (call_site_scope, source_info);
520 unpack!(builder.in_scope(call_site_s, LintLevel::Inherited, |builder| {
521 let arg_scope_s = (arg_scope, source_info);
522 // Attribute epilogue to function's closing brace
523 let fn_end = span_with_body.shrink_to_hi();
525 unpack!(builder.in_breakable_scope(None, Place::return_place(), fn_end, |builder| {
526 Some(builder.in_scope(arg_scope_s, LintLevel::Inherited, |builder| {
527 builder.args_and_body(
536 let source_info = builder.source_info(fn_end);
537 builder.cfg.terminate(return_block, source_info, TerminatorKind::Return);
538 builder.build_drop_trees();
542 let mut body = builder.finish();
544 body.spread_arg = if abi == Abi::RustCall {
545 // RustCall pseudo-ABI untuples the last argument.
546 Some(Local::new(arguments.len()))
550 if yield_ty.is_some() {
551 body.generator.as_mut().unwrap().yield_ty = yield_ty;
556 fn construct_const<'a, 'tcx>(
558 def: ty::WithOptConstParam<LocalDefId>,
559 thir: &'a Thir<'tcx>,
562 let hir_id = tcx.hir().local_def_id_to_hir_id(def.did);
564 // Figure out what primary body this item has.
565 let (span, const_ty_span) = match tcx.hir().get(hir_id) {
566 Node::Item(hir::Item {
567 kind: hir::ItemKind::Static(ty, _, _) | hir::ItemKind::Const(ty, _),
571 | Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(ty, _), span, .. })
572 | Node::TraitItem(hir::TraitItem {
573 kind: hir::TraitItemKind::Const(ty, Some(_)),
576 }) => (*span, ty.span),
577 Node::AnonConst(_) => {
578 let span = tcx.def_span(def.did);
581 _ => span_bug!(tcx.def_span(def.did), "can't build MIR for {:?}", def.did),
584 // Get the revealed type of this const. This is *not* the adjusted
585 // type of its body, which may be a subtype of this type. For
589 // static X: fn(&'static ()) = foo;
591 // The adjusted type of the body of X is `for<'a> fn(&'a ())` which
592 // is not the same as the type of X. We need the type of the return
593 // place to be the type of the constant because NLL typeck will
595 let typeck_results = tcx.typeck_opt_const_arg(def);
596 let const_ty = typeck_results.node_type(hir_id);
598 let infcx = tcx.infer_ctxt().build();
599 let mut builder = Builder::new(
612 let mut block = START_BLOCK;
613 unpack!(block = builder.expr_into_dest(Place::return_place(), block, &thir[expr]));
615 let source_info = builder.source_info(span);
616 builder.cfg.terminate(block, source_info, TerminatorKind::Return);
618 builder.build_drop_trees();
623 /// Construct MIR for an item that has had errors in type checking.
625 /// This is required because we may still want to run MIR passes on an item
626 /// with type errors, but normal MIR construction can't handle that in general.
627 fn construct_error<'tcx>(
630 body_owner_kind: hir::BodyOwnerKind,
631 err: ErrorGuaranteed,
633 let span = tcx.def_span(def);
634 let hir_id = tcx.hir().local_def_id_to_hir_id(def);
635 let generator_kind = tcx.generator_kind(def);
637 let ty = tcx.ty_error();
638 let num_params = match body_owner_kind {
639 hir::BodyOwnerKind::Fn => tcx.fn_sig(def).inputs().skip_binder().len(),
640 hir::BodyOwnerKind::Closure => {
641 let ty = tcx.type_of(def);
643 ty::Closure(_, substs) => {
644 1 + substs.as_closure().sig().inputs().skip_binder().len()
646 ty::Generator(..) => 2,
647 _ => bug!("expected closure or generator, found {ty:?}"),
650 hir::BodyOwnerKind::Const => 0,
651 hir::BodyOwnerKind::Static(_) => 0,
653 let mut cfg = CFG { basic_blocks: IndexVec::new() };
654 let mut source_scopes = IndexVec::new();
655 let mut local_decls = IndexVec::from_elem_n(LocalDecl::new(ty, span), 1);
657 cfg.start_new_block();
658 source_scopes.push(SourceScopeData {
662 inlined_parent_scope: None,
663 local_data: ClearCrossCrate::Set(SourceScopeLocalData {
665 safety: Safety::Safe,
668 let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE };
670 // Some MIR passes will expect the number of parameters to match the
671 // function declaration.
672 for _ in 0..num_params {
673 local_decls.push(LocalDecl::with_source_info(ty, source_info));
675 cfg.terminate(START_BLOCK, source_info, TerminatorKind::Unreachable);
677 let mut body = Body::new(
678 MirSource::item(def.to_def_id()),
689 body.generator.as_mut().map(|gen| gen.yield_ty = Some(ty));
693 impl<'a, 'tcx> Builder<'a, 'tcx> {
695 thir: &'a Thir<'tcx>,
696 infcx: InferCtxt<'tcx>,
697 def: ty::WithOptConstParam<LocalDefId>,
704 generator_kind: Option<GeneratorKind>,
705 ) -> Builder<'a, 'tcx> {
707 let attrs = tcx.hir().attrs(hir_id);
708 // Some functions always have overflow checks enabled,
709 // however, they may not get codegen'd, depending on
710 // the settings for the crate they are codegened in.
711 let mut check_overflow = tcx.sess.contains_name(attrs, sym::rustc_inherit_overflow_checks);
712 // Respect -C overflow-checks.
713 check_overflow |= tcx.sess.overflow_checks();
714 // Constants always need overflow checks.
715 check_overflow |= matches!(
716 tcx.hir().body_owner_kind(def.did),
717 hir::BodyOwnerKind::Const | hir::BodyOwnerKind::Static(_)
720 let lint_level = LintLevel::Explicit(hir_id);
721 let param_env = tcx.param_env(def.did);
722 let mut builder = Builder {
726 typeck_results: tcx.typeck_opt_const_arg(def),
727 region_scope_tree: tcx.region_scope_tree(def.did),
729 def_id: def.did.to_def_id(),
731 parent_module: tcx.parent_module(hir_id).to_def_id(),
733 cfg: CFG { basic_blocks: IndexVec::new() },
737 scopes: scope::Scopes::new(),
738 block_context: BlockContext::new(),
739 source_scopes: IndexVec::new(),
740 source_scope: OUTERMOST_SOURCE_SCOPE,
741 guard_context: vec![],
742 in_scope_unsafe: safety,
743 local_decls: IndexVec::from_elem_n(LocalDecl::new(return_ty, return_span), 1),
744 canonical_user_type_annotations: IndexVec::new(),
745 upvars: CaptureMap::new(),
746 var_indices: Default::default(),
748 var_debug_info: vec![],
751 assert_eq!(builder.cfg.start_new_block(), START_BLOCK);
753 builder.new_source_scope(span, lint_level, Some(safety)),
754 OUTERMOST_SOURCE_SCOPE
756 builder.source_scopes[OUTERMOST_SOURCE_SCOPE].parent_scope = None;
761 fn finish(self) -> Body<'tcx> {
762 for (index, block) in self.cfg.basic_blocks.iter().enumerate() {
763 if block.terminator.is_none() {
764 span_bug!(self.fn_span, "no terminator on block {:?}", index);
769 MirSource::item(self.def_id),
770 self.cfg.basic_blocks,
773 self.canonical_user_type_annotations,
778 self.typeck_results.tainted_by_errors,
784 mut block: BasicBlock,
785 fn_def_id: LocalDefId,
786 arguments: &IndexVec<ParamId, Param<'tcx>>,
787 argument_scope: region::Scope,
790 // Allocate locals for the function arguments
791 for param in arguments.iter() {
793 SourceInfo::outermost(param.pat.as_ref().map_or(self.fn_span, |pat| pat.span));
795 self.local_decls.push(LocalDecl::with_source_info(param.ty, source_info));
797 // If this is a simple binding pattern, give debuginfo a nice name.
798 if let Some(ref pat) = param.pat && let Some(name) = pat.simple_ident() {
799 self.var_debug_info.push(VarDebugInfo {
802 value: VarDebugInfoContents::Place(arg_local.into()),
808 let tcx_hir = tcx.hir();
809 let hir_typeck_results = self.typeck_results;
811 // In analyze_closure() in upvar.rs we gathered a list of upvars used by an
812 // indexed closure and we stored in a map called closure_min_captures in TypeckResults
813 // with the closure's DefId. Here, we run through that vec of UpvarIds for
814 // the given closure and use the necessary information to create upvar
815 // debuginfo and to fill `self.upvars`.
816 if hir_typeck_results.closure_min_captures.get(&fn_def_id).is_some() {
817 let mut closure_env_projs = vec![];
818 let mut closure_ty = self.local_decls[ty::CAPTURE_STRUCT_LOCAL].ty;
819 if let ty::Ref(_, ty, _) = closure_ty.kind() {
820 closure_env_projs.push(ProjectionElem::Deref);
823 let upvar_substs = match closure_ty.kind() {
824 ty::Closure(_, substs) => ty::UpvarSubsts::Closure(substs),
825 ty::Generator(_, substs, _) => ty::UpvarSubsts::Generator(substs),
826 _ => span_bug!(self.fn_span, "upvars with non-closure env ty {:?}", closure_ty),
828 let def_id = self.def_id.as_local().unwrap();
829 let capture_syms = tcx.symbols_for_closure_captures((def_id, fn_def_id));
830 let capture_tys = upvar_substs.upvar_tys();
831 let captures_with_tys = hir_typeck_results
832 .closure_min_captures_flattened(fn_def_id)
833 .zip(capture_tys.zip(capture_syms));
835 self.upvars = captures_with_tys
837 .map(|(i, (captured_place, (ty, sym)))| {
838 let capture = captured_place.info.capture_kind;
839 let var_id = match captured_place.place.base {
840 HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id,
841 _ => bug!("Expected an upvar"),
844 let mutability = captured_place.mutability;
846 let mut projs = closure_env_projs.clone();
847 projs.push(ProjectionElem::Field(Field::new(i), ty));
849 ty::UpvarCapture::ByValue => {}
850 ty::UpvarCapture::ByRef(..) => {
851 projs.push(ProjectionElem::Deref);
855 let use_place = Place {
856 local: ty::CAPTURE_STRUCT_LOCAL,
857 projection: tcx.intern_place_elems(&projs),
859 self.var_debug_info.push(VarDebugInfo {
861 source_info: SourceInfo::outermost(tcx_hir.span(var_id)),
862 value: VarDebugInfoContents::Place(use_place),
865 let capture = Capture { captured_place, use_place, mutability };
871 let mut scope = None;
872 // Bind the argument patterns
873 for (index, param) in arguments.iter().enumerate() {
874 // Function arguments always get the first Local indices after the return place
875 let local = Local::new(index + 1);
876 let place = Place::from(local);
878 // Make sure we drop (parts of) the argument even when not matched on.
880 param.pat.as_ref().map_or(expr.span, |pat| pat.span),
886 let Some(ref pat) = param.pat else {
889 let original_source_scope = self.source_scope;
891 if let Some(arg_hir_id) = param.hir_id {
892 self.set_correct_source_scope_for_arg(arg_hir_id, original_source_scope, span);
895 // Don't introduce extra copies for simple bindings
899 mode: BindingMode::ByValue,
903 self.local_decls[local].mutability = mutability;
904 self.local_decls[local].source_info.scope = self.source_scope;
905 self.local_decls[local].local_info = if let Some(kind) = param.self_kind {
906 Some(Box::new(LocalInfo::User(ClearCrossCrate::Set(
907 BindingForm::ImplicitSelf(kind),
910 let binding_mode = ty::BindingMode::BindByValue(mutability);
911 Some(Box::new(LocalInfo::User(ClearCrossCrate::Set(BindingForm::Var(
914 opt_ty_info: param.ty_span,
915 opt_match_place: Some((None, span)),
920 self.var_indices.insert(var, LocalsForNode::One(local));
923 scope = self.declare_bindings(
928 Some((Some(&place), span)),
930 let place_builder = PlaceBuilder::from(local);
931 unpack!(block = self.place_into_pattern(block, &pat, place_builder, false));
934 self.source_scope = original_source_scope;
937 // Enter the argument pattern bindings source scope, if it exists.
938 if let Some(source_scope) = scope {
939 self.source_scope = source_scope;
942 self.expr_into_dest(Place::return_place(), block, &expr)
945 fn set_correct_source_scope_for_arg(
947 arg_hir_id: hir::HirId,
948 original_source_scope: SourceScope,
952 let current_root = tcx.maybe_lint_level_root_bounded(arg_hir_id, self.hir_id);
953 let parent_root = tcx.maybe_lint_level_root_bounded(
954 self.source_scopes[original_source_scope]
957 .assert_crate_local()
961 if current_root != parent_root {
963 self.new_source_scope(pattern_span, LintLevel::Explicit(current_root), None);
967 fn get_unit_temp(&mut self) -> Place<'tcx> {
968 match self.unit_temp {
971 let ty = self.tcx.mk_unit();
972 let fn_span = self.fn_span;
973 let tmp = self.temp(ty, fn_span);
974 self.unit_temp = Some(tmp);
981 fn parse_float_into_constval<'tcx>(
983 float_ty: ty::FloatTy,
985 ) -> Option<ConstValue<'tcx>> {
986 parse_float_into_scalar(num, float_ty, neg).map(ConstValue::Scalar)
989 pub(crate) fn parse_float_into_scalar(
991 float_ty: ty::FloatTy,
993 ) -> Option<Scalar> {
994 let num = num.as_str();
996 ty::FloatTy::F32 => {
997 let Ok(rust_f) = num.parse::<f32>() else { return None };
998 let mut f = num.parse::<Single>().unwrap_or_else(|e| {
999 panic!("apfloat::ieee::Single failed to parse `{}`: {:?}", num, e)
1003 u128::from(rust_f.to_bits()) == f.to_bits(),
1004 "apfloat::ieee::Single gave different result for `{}`: \
1005 {}({:#x}) vs Rust's {}({:#x})",
1009 Single::from_bits(rust_f.to_bits().into()),
1017 Some(Scalar::from_f32(f))
1019 ty::FloatTy::F64 => {
1020 let Ok(rust_f) = num.parse::<f64>() else { return None };
1021 let mut f = num.parse::<Double>().unwrap_or_else(|e| {
1022 panic!("apfloat::ieee::Double failed to parse `{}`: {:?}", num, e)
1026 u128::from(rust_f.to_bits()) == f.to_bits(),
1027 "apfloat::ieee::Double gave different result for `{}`: \
1028 {}({:#x}) vs Rust's {}({:#x})",
1032 Double::from_bits(rust_f.to_bits().into()),
1040 Some(Scalar::from_f64(f))
1045 ///////////////////////////////////////////////////////////////////////////
1046 // Builder methods are broken up into modules, depending on what kind
1047 // of thing is being lowered. Note that they use the `unpack` macro
1048 // above extensively.
1058 pub(crate) use expr::category::Category as ExprCategory;