| use crate::build::expr::as_place::PlaceBuilder; |
| use crate::build::scope::DropKind; |
| use rustc_apfloat::ieee::{Double, Single}; |
| use rustc_apfloat::Float; |
| use rustc_ast::attr; |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_data_structures::sorted_map::SortedIndexMultiMap; |
| use rustc_errors::ErrorGuaranteed; |
| use rustc_hir as hir; |
| use rustc_hir::def::DefKind; |
| use rustc_hir::def_id::{DefId, LocalDefId}; |
| use rustc_hir::{GeneratorKind, Node}; |
| use rustc_index::{Idx, IndexSlice, IndexVec}; |
| use rustc_infer::infer::{InferCtxt, TyCtxtInferExt}; |
| use rustc_middle::hir::place::PlaceBase as HirPlaceBase; |
| use rustc_middle::middle::region; |
| use rustc_middle::mir::interpret::ConstValue; |
| use rustc_middle::mir::interpret::Scalar; |
| use rustc_middle::mir::*; |
| use rustc_middle::thir::{ |
| self, BindingMode, Expr, ExprId, LintLevel, LocalVarId, Param, ParamId, PatKind, Thir, |
| }; |
| use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt}; |
| use rustc_span::symbol::sym; |
| use rustc_span::Span; |
| use rustc_span::Symbol; |
| use rustc_target::abi::FieldIdx; |
| use rustc_target::spec::abi::Abi; |
| |
| use super::lints; |
| |
| pub(crate) fn mir_built( |
| tcx: TyCtxt<'_>, |
| def: LocalDefId, |
| ) -> &rustc_data_structures::steal::Steal<Body<'_>> { |
| tcx.alloc_steal_mir(mir_build(tcx, def)) |
| } |
| |
| /// Construct the MIR for a given `DefId`. |
| fn mir_build(tcx: TyCtxt<'_>, def: LocalDefId) -> Body<'_> { |
| // Ensure unsafeck and abstract const building is ran before we steal the THIR. |
| tcx.ensure_with_value().thir_check_unsafety(def); |
| tcx.ensure_with_value().thir_abstract_const(def); |
| if let Err(e) = tcx.check_match(def) { |
| return construct_error(tcx, def, e); |
| } |
| |
| let body = match tcx.thir_body(def) { |
| Err(error_reported) => construct_error(tcx, def, error_reported), |
| Ok((thir, expr)) => { |
| // We ran all queries that depended on THIR at the beginning |
| // of `mir_build`, so now we can steal it |
| let thir = thir.steal(); |
| |
| tcx.ensure().check_match(def); |
| // this must run before MIR dump, because |
| // "not all control paths return a value" is reported here. |
| // |
| // maybe move the check to a MIR pass? |
| tcx.ensure().check_liveness(def); |
| |
| match thir.body_type { |
| thir::BodyTy::Fn(fn_sig) => construct_fn(tcx, def, &thir, expr, fn_sig), |
| thir::BodyTy::Const(ty) => construct_const(tcx, def, &thir, expr, ty), |
| } |
| } |
| }; |
| |
| lints::check(tcx, &body); |
| |
| // The borrow checker will replace all the regions here with its own |
| // inference variables. There's no point having non-erased regions here. |
| // The exception is `body.user_type_annotations`, which is used unmodified |
| // by borrow checking. |
| debug_assert!( |
| !(body.local_decls.has_free_regions() |
| || body.basic_blocks.has_free_regions() |
| || body.var_debug_info.has_free_regions() |
| || body.yield_ty().has_free_regions()), |
| "Unexpected free regions in MIR: {:?}", |
| body, |
| ); |
| |
| body |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // BuildMir -- walks a crate, looking for fn items and methods to build MIR from |
| |
| #[derive(Debug, PartialEq, Eq)] |
| enum BlockFrame { |
| /// Evaluation is currently within a statement. |
| /// |
| /// Examples include: |
| /// 1. `EXPR;` |
| /// 2. `let _ = EXPR;` |
| /// 3. `let x = EXPR;` |
| Statement { |
| /// If true, then statement discards result from evaluating |
| /// the expression (such as examples 1 and 2 above). |
| ignores_expr_result: bool, |
| }, |
| |
| /// Evaluation is currently within the tail expression of a block. |
| /// |
| /// Example: `{ STMT_1; STMT_2; EXPR }` |
| TailExpr { |
| /// If true, then the surrounding context of the block ignores |
| /// the result of evaluating the block's tail expression. |
| /// |
| /// Example: `let _ = { STMT_1; EXPR };` |
| tail_result_is_ignored: bool, |
| |
| /// `Span` of the tail expression. |
| span: Span, |
| }, |
| |
| /// Generic mark meaning that the block occurred as a subexpression |
| /// where the result might be used. |
| /// |
| /// Examples: `foo(EXPR)`, `match EXPR { ... }` |
| SubExpr, |
| } |
| |
| impl BlockFrame { |
| fn is_tail_expr(&self) -> bool { |
| match *self { |
| BlockFrame::TailExpr { .. } => true, |
| |
| BlockFrame::Statement { .. } | BlockFrame::SubExpr => false, |
| } |
| } |
| fn is_statement(&self) -> bool { |
| match *self { |
| BlockFrame::Statement { .. } => true, |
| |
| BlockFrame::TailExpr { .. } | BlockFrame::SubExpr => false, |
| } |
| } |
| } |
| |
| #[derive(Debug)] |
| struct BlockContext(Vec<BlockFrame>); |
| |
| struct Builder<'a, 'tcx> { |
| tcx: TyCtxt<'tcx>, |
| infcx: InferCtxt<'tcx>, |
| region_scope_tree: &'tcx region::ScopeTree, |
| param_env: ty::ParamEnv<'tcx>, |
| |
| thir: &'a Thir<'tcx>, |
| cfg: CFG<'tcx>, |
| |
| def_id: LocalDefId, |
| hir_id: hir::HirId, |
| parent_module: DefId, |
| check_overflow: bool, |
| fn_span: Span, |
| arg_count: usize, |
| generator_kind: Option<GeneratorKind>, |
| |
| /// The current set of scopes, updated as we traverse; |
| /// see the `scope` module for more details. |
| scopes: scope::Scopes<'tcx>, |
| |
| /// The block-context: each time we build the code within an thir::Block, |
| /// we push a frame here tracking whether we are building a statement or |
| /// if we are pushing the tail expression of the block. This is used to |
| /// embed information in generated temps about whether they were created |
| /// for a block tail expression or not. |
| /// |
| /// It would be great if we could fold this into `self.scopes` |
| /// somehow, but right now I think that is very tightly tied to |
| /// the code generation in ways that we cannot (or should not) |
| /// start just throwing new entries onto that vector in order to |
| /// distinguish the context of EXPR1 from the context of EXPR2 in |
| /// `{ STMTS; EXPR1 } + EXPR2`. |
| block_context: BlockContext, |
| |
| /// The current unsafe block in scope |
| in_scope_unsafe: Safety, |
| |
| /// The vector of all scopes that we have created thus far; |
| /// we track this for debuginfo later. |
| source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>, |
| source_scope: SourceScope, |
| |
| /// The guard-context: each time we build the guard expression for |
| /// a match arm, we push onto this stack, and then pop when we |
| /// finish building it. |
| guard_context: Vec<GuardFrame>, |
| |
| /// Maps `HirId`s of variable bindings to the `Local`s created for them. |
| /// (A match binding can have two locals; the 2nd is for the arm's guard.) |
| var_indices: FxHashMap<LocalVarId, LocalsForNode>, |
| local_decls: IndexVec<Local, LocalDecl<'tcx>>, |
| canonical_user_type_annotations: ty::CanonicalUserTypeAnnotations<'tcx>, |
| upvars: CaptureMap<'tcx>, |
| unit_temp: Option<Place<'tcx>>, |
| |
| var_debug_info: Vec<VarDebugInfo<'tcx>>, |
| } |
| |
| type CaptureMap<'tcx> = SortedIndexMultiMap<usize, hir::HirId, Capture<'tcx>>; |
| |
| #[derive(Debug)] |
| struct Capture<'tcx> { |
| captured_place: &'tcx ty::CapturedPlace<'tcx>, |
| use_place: Place<'tcx>, |
| mutability: Mutability, |
| } |
| |
| impl<'a, 'tcx> Builder<'a, 'tcx> { |
| fn is_bound_var_in_guard(&self, id: LocalVarId) -> bool { |
| self.guard_context.iter().any(|frame| frame.locals.iter().any(|local| local.id == id)) |
| } |
| |
| fn var_local_id(&self, id: LocalVarId, for_guard: ForGuard) -> Local { |
| self.var_indices[&id].local_id(for_guard) |
| } |
| } |
| |
| impl BlockContext { |
| fn new() -> Self { |
| BlockContext(vec![]) |
| } |
| fn push(&mut self, bf: BlockFrame) { |
| self.0.push(bf); |
| } |
| fn pop(&mut self) -> Option<BlockFrame> { |
| self.0.pop() |
| } |
| |
| /// Traverses the frames on the `BlockContext`, searching for either |
| /// the first block-tail expression frame with no intervening |
| /// statement frame. |
| /// |
| /// Notably, this skips over `SubExpr` frames; this method is |
| /// meant to be used in the context of understanding the |
| /// relationship of a temp (created within some complicated |
| /// expression) with its containing expression, and whether the |
| /// value of that *containing expression* (not the temp!) is |
| /// ignored. |
| fn currently_in_block_tail(&self) -> Option<BlockTailInfo> { |
| for bf in self.0.iter().rev() { |
| match bf { |
| BlockFrame::SubExpr => continue, |
| BlockFrame::Statement { .. } => break, |
| &BlockFrame::TailExpr { tail_result_is_ignored, span } => { |
| return Some(BlockTailInfo { tail_result_is_ignored, span }); |
| } |
| } |
| } |
| |
| None |
| } |
| |
| /// Looks at the topmost frame on the BlockContext and reports |
| /// whether its one that would discard a block tail result. |
| /// |
| /// Unlike `currently_within_ignored_tail_expression`, this does |
| /// *not* skip over `SubExpr` frames: here, we want to know |
| /// whether the block result itself is discarded. |
| fn currently_ignores_tail_results(&self) -> bool { |
| match self.0.last() { |
| // no context: conservatively assume result is read |
| None => false, |
| |
| // sub-expression: block result feeds into some computation |
| Some(BlockFrame::SubExpr) => false, |
| |
| // otherwise: use accumulated is_ignored state. |
| Some( |
| BlockFrame::TailExpr { tail_result_is_ignored: ignored, .. } |
| | BlockFrame::Statement { ignores_expr_result: ignored }, |
| ) => *ignored, |
| } |
| } |
| } |
| |
| #[derive(Debug)] |
| enum LocalsForNode { |
| /// In the usual case, a `HirId` for an identifier maps to at most |
| /// one `Local` declaration. |
| One(Local), |
| |
| /// The exceptional case is identifiers in a match arm's pattern |
| /// that are referenced in a guard of that match arm. For these, |
| /// we have `2` Locals. |
| /// |
| /// * `for_arm_body` is the Local used in the arm body (which is |
| /// just like the `One` case above), |
| /// |
| /// * `ref_for_guard` is the Local used in the arm's guard (which |
| /// is a reference to a temp that is an alias of |
| /// `for_arm_body`). |
| ForGuard { ref_for_guard: Local, for_arm_body: Local }, |
| } |
| |
| #[derive(Debug)] |
| struct GuardFrameLocal { |
| id: LocalVarId, |
| } |
| |
| impl GuardFrameLocal { |
| fn new(id: LocalVarId, _binding_mode: BindingMode) -> Self { |
| GuardFrameLocal { id } |
| } |
| } |
| |
| #[derive(Debug)] |
| struct GuardFrame { |
| /// These are the id's of names that are bound by patterns of the |
| /// arm of *this* guard. |
| /// |
| /// (Frames higher up the stack will have the id's bound in arms |
| /// further out, such as in a case like: |
| /// |
| /// match E1 { |
| /// P1(id1) if (... (match E2 { P2(id2) if ... => B2 })) => B1, |
| /// } |
| /// |
| /// here, when building for FIXME. |
| locals: Vec<GuardFrameLocal>, |
| } |
| |
| /// `ForGuard` indicates whether we are talking about: |
| /// 1. The variable for use outside of guard expressions, or |
| /// 2. The temp that holds reference to (1.), which is actually what the |
| /// guard expressions see. |
| #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| enum ForGuard { |
| RefWithinGuard, |
| OutsideGuard, |
| } |
| |
| impl LocalsForNode { |
| fn local_id(&self, for_guard: ForGuard) -> Local { |
| match (self, for_guard) { |
| (&LocalsForNode::One(local_id), ForGuard::OutsideGuard) |
| | ( |
| &LocalsForNode::ForGuard { ref_for_guard: local_id, .. }, |
| ForGuard::RefWithinGuard, |
| ) |
| | (&LocalsForNode::ForGuard { for_arm_body: local_id, .. }, ForGuard::OutsideGuard) => { |
| local_id |
| } |
| |
| (&LocalsForNode::One(_), ForGuard::RefWithinGuard) => { |
| bug!("anything with one local should never be within a guard.") |
| } |
| } |
| } |
| } |
| |
| struct CFG<'tcx> { |
| basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>, |
| } |
| |
| rustc_index::newtype_index! { |
| struct ScopeId {} |
| } |
| |
| #[derive(Debug)] |
| enum NeedsTemporary { |
| /// Use this variant when whatever you are converting with `as_operand` |
| /// is the last thing you are converting. This means that if we introduced |
| /// an intermediate temporary, we'd only read it immediately after, so we can |
| /// also avoid it. |
| No, |
| /// For all cases where you aren't sure or that are too expensive to compute |
| /// for now. It is always safe to fall back to this. |
| Maybe, |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// The `BlockAnd` "monad" packages up the new basic block along with a |
| /// produced value (sometimes just unit, of course). The `unpack!` |
| /// macro (and methods below) makes working with `BlockAnd` much more |
| /// convenient. |
| |
| #[must_use = "if you don't use one of these results, you're leaving a dangling edge"] |
| struct BlockAnd<T>(BasicBlock, T); |
| |
| trait BlockAndExtension { |
| fn and<T>(self, v: T) -> BlockAnd<T>; |
| fn unit(self) -> BlockAnd<()>; |
| } |
| |
| impl BlockAndExtension for BasicBlock { |
| fn and<T>(self, v: T) -> BlockAnd<T> { |
| BlockAnd(self, v) |
| } |
| |
| fn unit(self) -> BlockAnd<()> { |
| BlockAnd(self, ()) |
| } |
| } |
| |
| /// Update a block pointer and return the value. |
| /// Use it like `let x = unpack!(block = self.foo(block, foo))`. |
| macro_rules! unpack { |
| ($x:ident = $c:expr) => {{ |
| let BlockAnd(b, v) = $c; |
| $x = b; |
| v |
| }}; |
| |
| ($c:expr) => {{ |
| let BlockAnd(b, ()) = $c; |
| b |
| }}; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// the main entry point for building MIR for a function |
| |
| fn construct_fn<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| fn_def: LocalDefId, |
| thir: &Thir<'tcx>, |
| expr: ExprId, |
| fn_sig: ty::FnSig<'tcx>, |
| ) -> Body<'tcx> { |
| let span = tcx.def_span(fn_def); |
| let fn_id = tcx.hir().local_def_id_to_hir_id(fn_def); |
| let generator_kind = tcx.generator_kind(fn_def); |
| |
| // The representation of thir for `-Zunpretty=thir-tree` relies on |
| // the entry expression being the last element of `thir.exprs`. |
| assert_eq!(expr.as_usize(), thir.exprs.len() - 1); |
| |
| // Figure out what primary body this item has. |
| let body_id = tcx.hir().body_owned_by(fn_def); |
| let span_with_body = tcx.hir().span_with_body(fn_id); |
| let return_ty_span = tcx |
| .hir() |
| .fn_decl_by_hir_id(fn_id) |
| .unwrap_or_else(|| span_bug!(span, "can't build MIR for {:?}", fn_def)) |
| .output |
| .span(); |
| |
| let safety = match fn_sig.unsafety { |
| hir::Unsafety::Normal => Safety::Safe, |
| hir::Unsafety::Unsafe => Safety::FnUnsafe, |
| }; |
| |
| let mut abi = fn_sig.abi; |
| if let DefKind::Closure = tcx.def_kind(fn_def) { |
| // HACK(eddyb) Avoid having RustCall on closures, |
| // as it adds unnecessary (and wrong) auto-tupling. |
| abi = Abi::Rust; |
| } |
| |
| let arguments = &thir.params; |
| |
| let (yield_ty, return_ty) = if generator_kind.is_some() { |
| let gen_ty = arguments[thir::UPVAR_ENV_PARAM].ty; |
| let gen_sig = match gen_ty.kind() { |
| ty::Generator(_, gen_substs, ..) => gen_substs.as_generator().sig(), |
| _ => { |
| span_bug!(span, "generator w/o generator type: {:?}", gen_ty) |
| } |
| }; |
| (Some(gen_sig.yield_ty), gen_sig.return_ty) |
| } else { |
| (None, fn_sig.output()) |
| }; |
| |
| if let Some(custom_mir_attr) = |
| tcx.hir().attrs(fn_id).iter().find(|attr| attr.name_or_empty() == sym::custom_mir) |
| { |
| return custom::build_custom_mir( |
| tcx, |
| fn_def.to_def_id(), |
| fn_id, |
| thir, |
| expr, |
| arguments, |
| return_ty, |
| return_ty_span, |
| span_with_body, |
| custom_mir_attr, |
| ); |
| } |
| |
| let infcx = tcx.infer_ctxt().build(); |
| let mut builder = Builder::new( |
| thir, |
| infcx, |
| fn_def, |
| fn_id, |
| span_with_body, |
| arguments.len(), |
| safety, |
| return_ty, |
| return_ty_span, |
| generator_kind, |
| ); |
| |
| let call_site_scope = |
| region::Scope { id: body_id.hir_id.local_id, data: region::ScopeData::CallSite }; |
| let arg_scope = |
| region::Scope { id: body_id.hir_id.local_id, data: region::ScopeData::Arguments }; |
| let source_info = builder.source_info(span); |
| let call_site_s = (call_site_scope, source_info); |
| unpack!(builder.in_scope(call_site_s, LintLevel::Inherited, |builder| { |
| let arg_scope_s = (arg_scope, source_info); |
| // Attribute epilogue to function's closing brace |
| let fn_end = span_with_body.shrink_to_hi(); |
| let return_block = |
| unpack!(builder.in_breakable_scope(None, Place::return_place(), fn_end, |builder| { |
| Some(builder.in_scope(arg_scope_s, LintLevel::Inherited, |builder| { |
| builder.args_and_body(START_BLOCK, arguments, arg_scope, &thir[expr]) |
| })) |
| })); |
| let source_info = builder.source_info(fn_end); |
| builder.cfg.terminate(return_block, source_info, TerminatorKind::Return); |
| builder.build_drop_trees(); |
| return_block.unit() |
| })); |
| |
| let mut body = builder.finish(); |
| |
| body.spread_arg = if abi == Abi::RustCall { |
| // RustCall pseudo-ABI untuples the last argument. |
| Some(Local::new(arguments.len())) |
| } else { |
| None |
| }; |
| if yield_ty.is_some() { |
| body.generator.as_mut().unwrap().yield_ty = yield_ty; |
| } |
| body |
| } |
| |
| fn construct_const<'a, 'tcx>( |
| tcx: TyCtxt<'tcx>, |
| def: LocalDefId, |
| thir: &'a Thir<'tcx>, |
| expr: ExprId, |
| const_ty: Ty<'tcx>, |
| ) -> Body<'tcx> { |
| let hir_id = tcx.hir().local_def_id_to_hir_id(def); |
| |
| // Figure out what primary body this item has. |
| let (span, const_ty_span) = match tcx.hir().get(hir_id) { |
| Node::Item(hir::Item { |
| kind: hir::ItemKind::Static(ty, _, _) | hir::ItemKind::Const(ty, _), |
| span, |
| .. |
| }) |
| | Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(ty, _), span, .. }) |
| | Node::TraitItem(hir::TraitItem { |
| kind: hir::TraitItemKind::Const(ty, Some(_)), |
| span, |
| .. |
| }) => (*span, ty.span), |
| Node::AnonConst(_) => { |
| let span = tcx.def_span(def); |
| (span, span) |
| } |
| _ => span_bug!(tcx.def_span(def), "can't build MIR for {:?}", def), |
| }; |
| |
| let infcx = tcx.infer_ctxt().build(); |
| let mut builder = Builder::new( |
| thir, |
| infcx, |
| def, |
| hir_id, |
| span, |
| 0, |
| Safety::Safe, |
| const_ty, |
| const_ty_span, |
| None, |
| ); |
| |
| let mut block = START_BLOCK; |
| unpack!(block = builder.expr_into_dest(Place::return_place(), block, &thir[expr])); |
| |
| let source_info = builder.source_info(span); |
| builder.cfg.terminate(block, source_info, TerminatorKind::Return); |
| |
| builder.build_drop_trees(); |
| |
| builder.finish() |
| } |
| |
| /// Construct MIR for an item that has had errors in type checking. |
| /// |
| /// This is required because we may still want to run MIR passes on an item |
| /// with type errors, but normal MIR construction can't handle that in general. |
| fn construct_error(tcx: TyCtxt<'_>, def: LocalDefId, err: ErrorGuaranteed) -> Body<'_> { |
| let span = tcx.def_span(def); |
| let hir_id = tcx.hir().local_def_id_to_hir_id(def); |
| let generator_kind = tcx.generator_kind(def); |
| let body_owner_kind = tcx.hir().body_owner_kind(def); |
| |
| let ty = tcx.ty_error(err); |
| let num_params = match body_owner_kind { |
| hir::BodyOwnerKind::Fn => tcx.fn_sig(def).skip_binder().inputs().skip_binder().len(), |
| hir::BodyOwnerKind::Closure => { |
| let ty = tcx.type_of(def).subst_identity(); |
| match ty.kind() { |
| ty::Closure(_, substs) => { |
| 1 + substs.as_closure().sig().inputs().skip_binder().len() |
| } |
| ty::Generator(..) => 2, |
| _ => bug!("expected closure or generator, found {ty:?}"), |
| } |
| } |
| hir::BodyOwnerKind::Const => 0, |
| hir::BodyOwnerKind::Static(_) => 0, |
| }; |
| let mut cfg = CFG { basic_blocks: IndexVec::new() }; |
| let mut source_scopes = IndexVec::new(); |
| let mut local_decls = IndexVec::from_elem_n(LocalDecl::new(ty, span), 1); |
| |
| cfg.start_new_block(); |
| source_scopes.push(SourceScopeData { |
| span, |
| parent_scope: None, |
| inlined: None, |
| inlined_parent_scope: None, |
| local_data: ClearCrossCrate::Set(SourceScopeLocalData { |
| lint_root: hir_id, |
| safety: Safety::Safe, |
| }), |
| }); |
| let source_info = SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }; |
| |
| // Some MIR passes will expect the number of parameters to match the |
| // function declaration. |
| for _ in 0..num_params { |
| local_decls.push(LocalDecl::with_source_info(ty, source_info)); |
| } |
| cfg.terminate(START_BLOCK, source_info, TerminatorKind::Unreachable); |
| |
| let mut body = Body::new( |
| MirSource::item(def.to_def_id()), |
| cfg.basic_blocks, |
| source_scopes, |
| local_decls, |
| IndexVec::new(), |
| num_params, |
| vec![], |
| span, |
| generator_kind, |
| Some(err), |
| ); |
| body.generator.as_mut().map(|gen| gen.yield_ty = Some(ty)); |
| body |
| } |
| |
| impl<'a, 'tcx> Builder<'a, 'tcx> { |
| fn new( |
| thir: &'a Thir<'tcx>, |
| infcx: InferCtxt<'tcx>, |
| def: LocalDefId, |
| hir_id: hir::HirId, |
| span: Span, |
| arg_count: usize, |
| safety: Safety, |
| return_ty: Ty<'tcx>, |
| return_span: Span, |
| generator_kind: Option<GeneratorKind>, |
| ) -> Builder<'a, 'tcx> { |
| let tcx = infcx.tcx; |
| let attrs = tcx.hir().attrs(hir_id); |
| // Some functions always have overflow checks enabled, |
| // however, they may not get codegen'd, depending on |
| // the settings for the crate they are codegened in. |
| let mut check_overflow = attr::contains_name(attrs, sym::rustc_inherit_overflow_checks); |
| // Respect -C overflow-checks. |
| check_overflow |= tcx.sess.overflow_checks(); |
| // Constants always need overflow checks. |
| check_overflow |= matches!( |
| tcx.hir().body_owner_kind(def), |
| hir::BodyOwnerKind::Const | hir::BodyOwnerKind::Static(_) |
| ); |
| |
| let lint_level = LintLevel::Explicit(hir_id); |
| let param_env = tcx.param_env(def); |
| let mut builder = Builder { |
| thir, |
| tcx, |
| infcx, |
| region_scope_tree: tcx.region_scope_tree(def), |
| param_env, |
| def_id: def, |
| hir_id, |
| parent_module: tcx.parent_module(hir_id).to_def_id(), |
| check_overflow, |
| cfg: CFG { basic_blocks: IndexVec::new() }, |
| fn_span: span, |
| arg_count, |
| generator_kind, |
| scopes: scope::Scopes::new(), |
| block_context: BlockContext::new(), |
| source_scopes: IndexVec::new(), |
| source_scope: OUTERMOST_SOURCE_SCOPE, |
| guard_context: vec![], |
| in_scope_unsafe: safety, |
| local_decls: IndexVec::from_elem_n(LocalDecl::new(return_ty, return_span), 1), |
| canonical_user_type_annotations: IndexVec::new(), |
| upvars: CaptureMap::new(), |
| var_indices: Default::default(), |
| unit_temp: None, |
| var_debug_info: vec![], |
| }; |
| |
| assert_eq!(builder.cfg.start_new_block(), START_BLOCK); |
| assert_eq!( |
| builder.new_source_scope(span, lint_level, Some(safety)), |
| OUTERMOST_SOURCE_SCOPE |
| ); |
| builder.source_scopes[OUTERMOST_SOURCE_SCOPE].parent_scope = None; |
| |
| builder |
| } |
| |
| fn finish(self) -> Body<'tcx> { |
| for (index, block) in self.cfg.basic_blocks.iter().enumerate() { |
| if block.terminator.is_none() { |
| span_bug!(self.fn_span, "no terminator on block {:?}", index); |
| } |
| } |
| |
| Body::new( |
| MirSource::item(self.def_id.to_def_id()), |
| self.cfg.basic_blocks, |
| self.source_scopes, |
| self.local_decls, |
| self.canonical_user_type_annotations, |
| self.arg_count, |
| self.var_debug_info, |
| self.fn_span, |
| self.generator_kind, |
| None, |
| ) |
| } |
| |
| fn insert_upvar_arg(&mut self) { |
| let Some(closure_arg) = self.local_decls.get(ty::CAPTURE_STRUCT_LOCAL) else { return }; |
| |
| let mut closure_ty = closure_arg.ty; |
| let mut closure_env_projs = vec![]; |
| if let ty::Ref(_, ty, _) = closure_ty.kind() { |
| closure_env_projs.push(ProjectionElem::Deref); |
| closure_ty = *ty; |
| } |
| |
| let upvar_substs = match closure_ty.kind() { |
| ty::Closure(_, substs) => ty::UpvarSubsts::Closure(substs), |
| ty::Generator(_, substs, _) => ty::UpvarSubsts::Generator(substs), |
| _ => return, |
| }; |
| |
| // In analyze_closure() in upvar.rs we gathered a list of upvars used by an |
| // indexed closure and we stored in a map called closure_min_captures in TypeckResults |
| // with the closure's DefId. Here, we run through that vec of UpvarIds for |
| // the given closure and use the necessary information to create upvar |
| // debuginfo and to fill `self.upvars`. |
| let capture_tys = upvar_substs.upvar_tys(); |
| |
| let tcx = self.tcx; |
| self.upvars = tcx |
| .closure_captures(self.def_id) |
| .iter() |
| .zip(capture_tys) |
| .enumerate() |
| .map(|(i, (captured_place, ty))| { |
| let name = captured_place.to_symbol(); |
| |
| let capture = captured_place.info.capture_kind; |
| let var_id = match captured_place.place.base { |
| HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id, |
| _ => bug!("Expected an upvar"), |
| }; |
| |
| let mutability = captured_place.mutability; |
| |
| let mut projs = closure_env_projs.clone(); |
| projs.push(ProjectionElem::Field(FieldIdx::new(i), ty)); |
| match capture { |
| ty::UpvarCapture::ByValue => {} |
| ty::UpvarCapture::ByRef(..) => { |
| projs.push(ProjectionElem::Deref); |
| } |
| }; |
| |
| let use_place = Place { |
| local: ty::CAPTURE_STRUCT_LOCAL, |
| projection: tcx.mk_place_elems(&projs), |
| }; |
| self.var_debug_info.push(VarDebugInfo { |
| name, |
| references: 0, |
| source_info: SourceInfo::outermost(captured_place.var_ident.span), |
| value: VarDebugInfoContents::Place(use_place), |
| argument_index: None, |
| }); |
| |
| let capture = Capture { captured_place, use_place, mutability }; |
| (var_id, capture) |
| }) |
| .collect(); |
| } |
| |
| fn args_and_body( |
| &mut self, |
| mut block: BasicBlock, |
| arguments: &IndexSlice<ParamId, Param<'tcx>>, |
| argument_scope: region::Scope, |
| expr: &Expr<'tcx>, |
| ) -> BlockAnd<()> { |
| // Allocate locals for the function arguments |
| for (argument_index, param) in arguments.iter().enumerate() { |
| let source_info = |
| SourceInfo::outermost(param.pat.as_ref().map_or(self.fn_span, |pat| pat.span)); |
| let arg_local = |
| self.local_decls.push(LocalDecl::with_source_info(param.ty, source_info)); |
| |
| // If this is a simple binding pattern, give debuginfo a nice name. |
| if let Some(ref pat) = param.pat && let Some(name) = pat.simple_ident() { |
| self.var_debug_info.push(VarDebugInfo { |
| name, |
| source_info, |
| references: 0, |
| value: VarDebugInfoContents::Place(arg_local.into()), |
| argument_index: Some(argument_index as u16 + 1), |
| }); |
| } |
| } |
| |
| self.insert_upvar_arg(); |
| |
| let mut scope = None; |
| // Bind the argument patterns |
| for (index, param) in arguments.iter().enumerate() { |
| // Function arguments always get the first Local indices after the return place |
| let local = Local::new(index + 1); |
| let place = Place::from(local); |
| |
| // Make sure we drop (parts of) the argument even when not matched on. |
| self.schedule_drop( |
| param.pat.as_ref().map_or(expr.span, |pat| pat.span), |
| argument_scope, |
| local, |
| DropKind::Value, |
| ); |
| |
| let Some(ref pat) = param.pat else { |
| continue; |
| }; |
| let original_source_scope = self.source_scope; |
| let span = pat.span; |
| if let Some(arg_hir_id) = param.hir_id { |
| self.set_correct_source_scope_for_arg(arg_hir_id, original_source_scope, span); |
| } |
| match pat.kind { |
| // Don't introduce extra copies for simple bindings |
| PatKind::Binding { |
| mutability, |
| var, |
| mode: BindingMode::ByValue, |
| subpattern: None, |
| .. |
| } => { |
| self.local_decls[local].mutability = mutability; |
| self.local_decls[local].source_info.scope = self.source_scope; |
| **self.local_decls[local].local_info.as_mut().assert_crate_local() = |
| if let Some(kind) = param.self_kind { |
| LocalInfo::User(BindingForm::ImplicitSelf(kind)) |
| } else { |
| let binding_mode = ty::BindingMode::BindByValue(mutability); |
| LocalInfo::User(BindingForm::Var(VarBindingForm { |
| binding_mode, |
| opt_ty_info: param.ty_span, |
| opt_match_place: Some((None, span)), |
| pat_span: span, |
| })) |
| }; |
| self.var_indices.insert(var, LocalsForNode::One(local)); |
| } |
| _ => { |
| scope = self.declare_bindings( |
| scope, |
| expr.span, |
| &pat, |
| None, |
| Some((Some(&place), span)), |
| ); |
| let place_builder = PlaceBuilder::from(local); |
| unpack!(block = self.place_into_pattern(block, &pat, place_builder, false)); |
| } |
| } |
| self.source_scope = original_source_scope; |
| } |
| |
| // Enter the argument pattern bindings source scope, if it exists. |
| if let Some(source_scope) = scope { |
| self.source_scope = source_scope; |
| } |
| |
| self.expr_into_dest(Place::return_place(), block, &expr) |
| } |
| |
| fn set_correct_source_scope_for_arg( |
| &mut self, |
| arg_hir_id: hir::HirId, |
| original_source_scope: SourceScope, |
| pattern_span: Span, |
| ) { |
| let parent_id = self.source_scopes[original_source_scope] |
| .local_data |
| .as_ref() |
| .assert_crate_local() |
| .lint_root; |
| self.maybe_new_source_scope(pattern_span, None, arg_hir_id, parent_id); |
| } |
| |
| fn get_unit_temp(&mut self) -> Place<'tcx> { |
| match self.unit_temp { |
| Some(tmp) => tmp, |
| None => { |
| let ty = self.tcx.mk_unit(); |
| let fn_span = self.fn_span; |
| let tmp = self.temp(ty, fn_span); |
| self.unit_temp = Some(tmp); |
| tmp |
| } |
| } |
| } |
| } |
| |
| fn parse_float_into_constval<'tcx>( |
| num: Symbol, |
| float_ty: ty::FloatTy, |
| neg: bool, |
| ) -> Option<ConstValue<'tcx>> { |
| parse_float_into_scalar(num, float_ty, neg).map(ConstValue::Scalar) |
| } |
| |
| pub(crate) fn parse_float_into_scalar( |
| num: Symbol, |
| float_ty: ty::FloatTy, |
| neg: bool, |
| ) -> Option<Scalar> { |
| let num = num.as_str(); |
| match float_ty { |
| ty::FloatTy::F32 => { |
| let Ok(rust_f) = num.parse::<f32>() else { return None }; |
| let mut f = num.parse::<Single>().unwrap_or_else(|e| { |
| panic!("apfloat::ieee::Single failed to parse `{}`: {:?}", num, e) |
| }); |
| |
| assert!( |
| u128::from(rust_f.to_bits()) == f.to_bits(), |
| "apfloat::ieee::Single gave different result for `{}`: \ |
| {}({:#x}) vs Rust's {}({:#x})", |
| rust_f, |
| f, |
| f.to_bits(), |
| Single::from_bits(rust_f.to_bits().into()), |
| rust_f.to_bits() |
| ); |
| |
| if neg { |
| f = -f; |
| } |
| |
| Some(Scalar::from_f32(f)) |
| } |
| ty::FloatTy::F64 => { |
| let Ok(rust_f) = num.parse::<f64>() else { return None }; |
| let mut f = num.parse::<Double>().unwrap_or_else(|e| { |
| panic!("apfloat::ieee::Double failed to parse `{}`: {:?}", num, e) |
| }); |
| |
| assert!( |
| u128::from(rust_f.to_bits()) == f.to_bits(), |
| "apfloat::ieee::Double gave different result for `{}`: \ |
| {}({:#x}) vs Rust's {}({:#x})", |
| rust_f, |
| f, |
| f.to_bits(), |
| Double::from_bits(rust_f.to_bits().into()), |
| rust_f.to_bits() |
| ); |
| |
| if neg { |
| f = -f; |
| } |
| |
| Some(Scalar::from_f64(f)) |
| } |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Builder methods are broken up into modules, depending on what kind |
| // of thing is being lowered. Note that they use the `unpack` macro |
| // above extensively. |
| |
| mod block; |
| mod cfg; |
| mod custom; |
| mod expr; |
| mod matches; |
| mod misc; |
| mod scope; |
| |
| pub(crate) use expr::category::Category as ExprCategory; |
